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Yang X, Yang Y, Li Y, Li Z, Zhang Y, He X, Yang J. Real-time imaging and quantitative analysis of internal gap formation in bulk-fill and conventional resin composites: An OCT evaluation. Photodiagnosis Photodyn Ther 2024; 47:104103. [PMID: 38677500 DOI: 10.1016/j.pdpdt.2024.104103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 04/19/2024] [Accepted: 04/24/2024] [Indexed: 04/29/2024]
Abstract
BACKGROUND This study used optical coherence tomography (OCT) to observe real-time internal gap formation in both bulk-fill and conventional resin composites. It aimed to provide a quantitative analysis of variations, addressing the inconclusive nature of microleakage assessment caused by differences in testing methods. METHODS Fifty extracted third molars prepared with Class I cavities, were divided into five groups (n = 10). Conventional resin Filtek Z350 XT (FZX) was applied with a double-layer filling of 2 mm per layer. Bulk-fill resins X-tra fil (XTF), Filtek Bulk Fill Posterior Restorative (FBP), Surefil SDR Flow + (SDR), and Filtek Flowable Restorative (FFR) were applied with a single-layer filling of 4 mm. Real-time OCT imaging was conducted during light curing. Post-curing, the entire sample was OCT-scanned. Following this, ImageJ software was used to measure the gap (G1 %). Subsequently, thermal cycling (TC) (5000 times, 5 °C-55 °C) was applied, followed by OCT scanning to calculate the gap (G2 %) and ΔG%. Data were analyzed using two-way repeated measures ANOVA, Kruskal-Wallis test, and Duncan's test (α=0.05). RESULTS There was no significant difference in G1 % among the groups (p > 0.05). Following TC, FZX exhibited the highest G2 %, succeeded by FFR, FBP, XTF, and SDR, with SDR demonstrating the lowest G2 % (p < 0.05). FZX showed the highest ΔG% (p < 0.05), while SDR exhibited the lowest ΔG% (p < 0.05). CONCLUSION OCT proves to be a promising tool for detecting microleakage. TC exerted a more significant negative impact on conventional resin. Surefil SDR Flow + displayed the least microleakage, both before and after TC.
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Affiliation(s)
- Xinyu Yang
- Department of Cariology & Endodontics, The Affiliated Stomatological Hospital, Jiangxi Medical College, Nanchang University, Nanchang 330006, Jiangxi, China; Jiangxi Province Key Laboratory of Oral Biomedicine, Nanchang 330006, Jiangxi, China
| | - Yuhao Yang
- Department of Cariology & Endodontics, The Affiliated Stomatological Hospital, Jiangxi Medical College, Nanchang University, Nanchang 330006, Jiangxi, China; Jiangxi Province Key Laboratory of Oral Biomedicine, Nanchang 330006, Jiangxi, China
| | - Yingji Li
- Key Laboratory of Opto-Electronic Information Science and Technology of Jiangxi Province and Jiangxi Engineering Laboratory for Optoelectronics Testing Technology, Nanchang Hangkong University, Nanchang 330063, Jiangxi, China
| | - Zekun Li
- Department of Cariology & Endodontics, The Affiliated Stomatological Hospital, Jiangxi Medical College, Nanchang University, Nanchang 330006, Jiangxi, China; Jiangxi Province Key Laboratory of Oral Biomedicine, Nanchang 330006, Jiangxi, China
| | - Yubao Zhang
- Key Laboratory of Opto-Electronic Information Science and Technology of Jiangxi Province and Jiangxi Engineering Laboratory for Optoelectronics Testing Technology, Nanchang Hangkong University, Nanchang 330063, Jiangxi, China
| | - Xingdao He
- Key Laboratory of Opto-Electronic Information Science and Technology of Jiangxi Province and Jiangxi Engineering Laboratory for Optoelectronics Testing Technology, Nanchang Hangkong University, Nanchang 330063, Jiangxi, China
| | - Jian Yang
- Department of Cariology & Endodontics, The Affiliated Stomatological Hospital, Jiangxi Medical College, Nanchang University, Nanchang 330006, Jiangxi, China; Jiangxi Province Key Laboratory of Oral Biomedicine, Nanchang 330006, Jiangxi, China.
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Basheer RR, Hasanain FA, Abuelenain DA. Evaluating flexure properties, hardness, roughness and microleakage of high-strength injectable dental composite: an in vitro study. BMC Oral Health 2024; 24:546. [PMID: 38730400 PMCID: PMC11088093 DOI: 10.1186/s12903-024-04333-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Accepted: 05/03/2024] [Indexed: 05/12/2024] Open
Abstract
BACKGROUND Recently, a new generation of high-strength flowable dental composites has been introduced by manufacturers. The manufacturers claim that these materials have enhanced mechanical and physical properties and are suitable for use in a wide range of direct anterior and posterior restorations, even in high-stress bearing areas. AIM The objective of this study was to assess certain physical and mechanical properties of these recently introduced high-strength flowable composites in comparison to conventional multipurpose dental composites. METHODS Four types of high-strength flowable composites (Genial Universal FLO, Gaenial Universal Injectable, Beautifil Injectable, and Beautifil Flow Plus) were tested in experimental groups, while a nanohybrid conventional composite (Filtek Z350 XT) was used as the control. For flexure properties, ten rectangular samples (2 × 2 × 25 mm) were prepared from each composite material and subjected to 5000 cycles of thermocycling. Samples were then subjected to flexural strength testing using the universal testing machine. Another twenty disc-shaped specimens of dimensions (5 mm diameter × 2 mm thickness) were fabricated from each composite material for surface roughness (Ra) (n = 10) and hardness (VHN) test (n = 10). All samples underwent 5000 cycles of thermocycling before testing. Additionally, microleakage testing was conducted on 60 standardized class V cavities prepared on molar teeth and divided randomly into five groups (n = 12). Cavities were then filled with composite according to the manufacturer's instructions and subjected to thermocycling for 1000 cycles before testing using methylene blue solution and a stereomicroscope. RESULTS All tested materials were comparable to the control group in terms of flexural strength and surface roughness (p > 0.05), with Gaenial Universal FLO exhibiting significantly higher flexural strength compared to the other flowable composite materials tested. However, all tested materials demonstrated significantly lower elastic modulus and surface hardness than the control group (p < 0.05). The control group exhibited higher microleakage scores, while the lowest scores were observed in the Gaenial Universal FLO material (p < 0.05) CONCLUSION: The physical and mechanical behaviors of the different high-strength flowable composites investigated in this study varied. Some of these materials may serve as suitable alternatives to conventional composites in specific applications, emphasizing the importance of dentists being familiar with material properties before making material selections.
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Affiliation(s)
- Rasha R Basheer
- Restorative Dentistry Department, Operative dentistry division, King Abdulaziz University, Jeddah, Saudi Arabia.
- Conservative Dentistry Department, Faculty of Dentistry, October University for Modern Sciences and Arts, Giza, Egypt.
| | - Fatin A Hasanain
- Restorative Dentistry Department, Operative dentistry division, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Dalia A Abuelenain
- Restorative Dentistry Department, Operative dentistry division, King Abdulaziz University, Jeddah, Saudi Arabia
- Restorative Dentistry Department, Biomaterials Division, King Abdulaziz University, Jeddah, Saudi Arabia
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Guarneri JAG, Chima MVA, Assis DG, Rueggeberg FA, Arrais CAG. Influence of light exposure techniques on in vitro pulp temperature rise during bulk fill composite Class I restorations. Odontology 2024; 112:479-488. [PMID: 37938400 DOI: 10.1007/s10266-023-00867-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 10/16/2023] [Indexed: 11/09/2023]
Abstract
This in vitro study assessed peak temperature and temperature increase (ΔT) within the pulp chamber during different extended photoactivation techniques (EPT-applying similar radiant exposure values) to resin-based composites (RBCs) placed in a Class I cavity preparation in an extracted human lower third molar. A T-type thermocouple was placed in the pulp chamber and connected to a temperature analysis device (Thermes, Physitemp). The tooth was attached to an assembly simulating the in vivo environment (controlled baseline pulp chamber temperature and fluid flow). The real-time pulp chamber temperature was evaluated throughout the photoactivation (Bluephase N, Ivoclar Vivadent) of two bulk-fill RBCs: Tetric N Ceram Bulk Fill (TBF; shade: IVA; Ivoclar Vivadent); Surefill SDR flow + (SDR, shade: Universal; Dentsply Sirona), which were exposed to different curing techniques: 40 s-occlusal surface; 20 s-occlusal + 10 s-buccal + 10 s-lingual surfaces; 10 s-buccal + 10 s + lingual + 20 s-occlusal surfaces. Each EPT delivered 42.4 J/cm2. Vickers hardness (VHN) was measured on the removed, sectioned RBC restorations at the top and bottom middle areas after curing. ΔT and VHN data were analyzed using 2-way ANOVA followed by Bonferroni post-hoc test (α = 0.05). Peak temperature data were analyzed using one-way ANOVA and Dunnett's post-hoc test (α = 0.05). SDR showed higher ΔT values than TBF (p = 0.008) in some EPTs. Neither technique resulted in ΔT values greater than 5.5 °C. Both composites had acceptable bottom/top hardness ratios (greater than 80%), regardless of the photoactivation technique. The evaluated EPTs may be considered safe as a low-temperature increase was noticed within the pulp chamber.
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Affiliation(s)
- Juliana Anany Gonzales Guarneri
- Department of Restorative Dentistry, State University of Ponta Grossa, General Carlos Cavalcanti St., 4748, Uvaranas, Ponta Grossa, Parana, 84030-900, Brazil
| | - Maria Victoria Arteaga Chima
- Department of Restorative Dentistry, State University of Ponta Grossa, General Carlos Cavalcanti St., 4748, Uvaranas, Ponta Grossa, Parana, 84030-900, Brazil
| | - Danielle Gomes Assis
- Department of Restorative Dentistry, State University of Ponta Grossa, General Carlos Cavalcanti St., 4748, Uvaranas, Ponta Grossa, Parana, 84030-900, Brazil
| | - Frederick Allen Rueggeberg
- Dental Materials Section, Department of Restorative Sciences, Dental College of Georgia, Augusta University, Room GC 4344, 1430 John Wesley Gilbert Drive, Augusta, GA, 30912, USA
| | - Cesar Augusto Galvão Arrais
- Department of Restorative Dentistry, State University of Ponta Grossa, General Carlos Cavalcanti St., 4748, Uvaranas, Ponta Grossa, Parana, 84030-900, Brazil.
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Baltacioğlu İH, Demirel G, Öztürk B, Aydin F, Orhan K. Marginal adaptation of bulk-fill resin composites with different viscosities in class II restorations: a micro-CT evaluation. BMC Oral Health 2024; 24:228. [PMID: 38350901 PMCID: PMC10863248 DOI: 10.1186/s12903-024-03975-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 02/02/2024] [Indexed: 02/15/2024] Open
Abstract
BACKGROUND The purpose of this study is to evaluate the marginal adaptation of bulk-fill resin composites with different viscosities (paste-like and flowable) in Class II restorations using micro-CT imaging. METHODS Forty extracted human molars were used. Mesial and distal Class II box cavities (approximately 3 mm x 3 mm x 4 mm) were prepared for each tooth, with cavity floors located 1 mm below the enamel-cementum junction. Following adhesive application, teeth were restored using eight different groups: Group XB: X-tra Base Bulk-fill Flowable (VOCO), Group XF: X-tra Fill Bulk-fill (VOCO), Group FB: Filtek Bulk-fill Posterior (3 M ESPE), Group FF: Filtek Bulk-fill Flowable (3 M ESPE), Group BB: Beautifil-Bulk (SHOFU), Group BF: Beautifil-Bulk Flowable (SHOFU), and Group CO: "as a control group", Clearfil Majesty Posterior (KURARAY) and Group CF: "as a control group", Clearfil Majesty Flow + Clearfil Majesty Posterior (KURARAY). The restored teeth underwent an aging protocol involving 1000 cycles in a water bath fluctuating between 5 ± 1.0 °C and 55 ± 1.0 °C. Post-aging, teeth were immersed in 50% silver nitrate solution for 24 h and then in a film developer solution for 8 h. Microleakage analysis was performed using micro-CT, evaluated with 3D Slicer software. A two-way ANOVA was employed for statistical analysis. RESULTS Two-way ANOVA results indicated significant effects of both viscosity (p < 0.0001) and composite type (p < 0.0001) on marginal adaptation. Viscosity analysis (comparing flowable and paste-like) revealed no significant differences in the FB-FF, XB-XF and BB-BF groups but significant differences in the and CO-CF group, with flowable type exhibiting less microleakage than paste-like type. CONCLUSIONS The study suggests that while the viscosity of bulk-fill composites did not significantly affect marginal adaptation, the brand of bulk-fill composite did influence it.
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Affiliation(s)
| | - Gülbike Demirel
- Department of Restorative Dentistry, Faculty of Dentistry, Ankara University, Ankara, Turkey.
| | - Burcu Öztürk
- Department of Restorative Dentistry, Faculty of Dentistry, Ankara University, Ankara, Turkey
| | - Fulya Aydin
- Department of Restorative Dentistry, Faculty of Dentistry, Ankara Medipol University, Ankara, Turkey
| | - Kaan Orhan
- Department of Maxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara, Turkey
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Hu P, Xu H, Pan Y, Sang X, Liu R. Upconversion particle-assisted NIR polymerization enables microdomain gradient photopolymerization at inter-particulate length scale. Nat Commun 2023; 14:3653. [PMID: 37339956 DOI: 10.1038/s41467-023-39440-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 06/14/2023] [Indexed: 06/22/2023] Open
Abstract
High crosslinking and low shrinkage stress are difficult to reconcile in the preparation of performance-enhancing photopolymer materials. Here we report the unique mechanism of upconversion particles-assisted NIR polymerization (UCAP) in reducing shrinkage stress and enhancing mechanical properties of cured materials. The excited upconversion particle emit UV-vis light with gradient intensity to the surroundings, forming a domain-limited gradient photopolymerization centered on the particle, and the photopolymer grows within this domain. The curing system remains fluid until the percolated photopolymer network is formed and starts gelation at high functional group conversion, with most of the shrinkage stresses generated by the crosslinking reaction having been released prior to gelation. Longer exposures after gelation contribute to a homogeneous solidification of cured material, and polymer materials cured by UCAP exhibit high gel point conversion, low shrinkage stress and strong mechanical properties than those cured by conventional UV polymerization techniques.
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Affiliation(s)
- Peng Hu
- International Research Center for Photoresponsive Molecules and Materials, Jiangnan University, Wuxi, 214122, Jiangsu, PR China
| | - Hang Xu
- International Research Center for Photoresponsive Molecules and Materials, Jiangnan University, Wuxi, 214122, Jiangsu, PR China
| | - Yue Pan
- International Research Center for Photoresponsive Molecules and Materials, Jiangnan University, Wuxi, 214122, Jiangsu, PR China
| | - Xinxin Sang
- International Research Center for Photoresponsive Molecules and Materials, Jiangnan University, Wuxi, 214122, Jiangsu, PR China
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, Jiangnan University, Wuxi, 214122, Jiangsu, PR China
| | - Ren Liu
- International Research Center for Photoresponsive Molecules and Materials, Jiangnan University, Wuxi, 214122, Jiangsu, PR China.
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, Jiangnan University, Wuxi, 214122, Jiangsu, PR China.
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Wylie ME, Parashos P, Fernando JR, Palamara J, Sloan AJ. Biological considerations of dental materials as orifice barriers for restoring root-filled teeth. Aust Dent J 2023; 68 Suppl 1:S82-S95. [PMID: 37607102 DOI: 10.1111/adj.12970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/02/2023] [Indexed: 08/24/2023]
Abstract
There is ample published literature regarding the technical aspects of restoring root-filled teeth, but little concerning the biological impacts, consequences, and criteria for the selection of direct restorative materials following endodontic treatment. The provision of an effective coronal seal in addition to a sound root filling is known to be important in the prevention of root canal infection. This review seeks to explore the evidence concerning the selection of dental materials in the restoration of root-filled teeth, specifically with a close examination of the properties of commonly used materials as orifice barriers. © 2023 Australian Dental Association.
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Affiliation(s)
- M E Wylie
- Melbourne Dental School, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - P Parashos
- Melbourne Dental School, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - J R Fernando
- Melbourne Dental School, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Victoria, Australia
- Centre for Oral Health Research, Melbourne Dental School, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Jea Palamara
- Melbourne Dental School, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - A J Sloan
- Melbourne Dental School, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Victoria, Australia
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Leyva Del Rio D, Johnston WM. Effect of monomer composition and filler fraction on surface microhardness and depth of cure of experimental resin composites. Eur J Oral Sci 2023; 131:e12933. [PMID: 37121780 DOI: 10.1111/eos.12933] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 03/28/2023] [Indexed: 05/02/2023]
Abstract
This study evaluated microhardness profiles and calculated depths of cure at 80% of the surface microhardness of experimental dental resin composites having different base monomer compositions and different filler fractions. Composites were prepared using four different base monomers (bisphenol A-glycidyl methacrylate [Bis-GMA], urethane dimethacrylate [UDMA], ethoxylated bisphenol-A dimethacrylate [Bis-EMA], and Fit-852) with triethylene glycol dimethacrylate (TEGDMA) used as a co-monomer at three filler:resin matrix weight percent fractions (50:50, 60:40, and 70:30). Uncured material was placed in 3D printed molds and light cured for 40 s from the top surface only. Knoop microhardness was measured at the top of the specimen, and at every 0.5 mm up to 4 mm in depth. Microhardness at the surface increased in all experimental composites as the filler fraction increased. When comparing base monomers, microhardness was the highest in UDMA-based composites, while Bis-GMA-based composites showed the lowest values. When comparing depth of cure as a function of base monomer type, both Bis-GMA and Bis-EMA showed significantly lower values than UDMA or Fit-852. Composites having 50 wt% filler showed a significantly higher depth of cure than those with 60 and 70 wt% filler. Base monomer and filler fraction significantly influence microhardness and depth of cure in these experimental composites.
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Affiliation(s)
- Diana Leyva Del Rio
- The Ohio State University, College of Dentistry, Division of Restorative and Prosthetic Dentistry, Columbus, Ohio, USA
| | - William Michael Johnston
- The Ohio State University, College of Dentistry, Division of Restorative and Prosthetic Dentistry, Columbus, Ohio, USA
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Maucoski C, Price RB, Rocha MG, Roulet JF, Sullivan B. Ability of short exposures from laser and quad-wave curing lights to photo-cure bulk-fill resin-based composites. Dent Mater 2023; 39:275-292. [PMID: 36868892 DOI: 10.1016/j.dental.2023.01.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 01/10/2023] [Accepted: 01/25/2023] [Indexed: 03/05/2023]
Abstract
OBJECTIVE This study investigated the ability of a laser, and a 'quad-wave' LCU, to photo-cure paste and flowable bulk-fill resin-based composites (RBCs). METHODS Five LCUs and nine exposure conditions were used. The laser LCU (Monet) used for 1 s and 3 s, the quad-wave LCU (PinkWave) used for 3 s in the Boost and 20 s in the Standard modes, the the multi-peak LCU (Valo X) used for 5 s in the Xtra and 20 s in the Standard modes, were compared to the polywave PowerCure used in the 3 s mode and for 20 s in the Standard mode, and to the mono-peak SmartLite Pro used for 20 s. Two paste consistency bulk-fill RBCs: Filtek One Bulk Fill Shade A2 (3 M), Tetric PowerFill Shade IVA (Ivoclar Vivadent), and two flowable RBCs: Filtek Bulk Fill Flowable Shade A2 (3 M), Tetric PowerFlow Shade IVA (Ivoclar Vivadent) were photo-cured in 4-mm deep x 4-mm diameter metal molds. The light received by these specimens was measured using a spectrometer (Flame-T, Ocean Insight), and the radiant exposure delivered to the top surface of the RBCs was mapped. The immediate degree of conversion (DC) at the bottom, and the 24-hour Vickers Hardness (VH) at the top and bottom of the RBCs were measured and compared. RESULTS The irradiance received by the 4-mm diameter specimens ranged from 1035 mW/cm2 (SmartLite Pro) to 5303 mW/cm2 (Monet). The radiant exposures between 350 and 500 nm delivered to the top surface of the RBCs ranged from 5.3 J/cm2 (Monet in 1 s) to 26.4 J/cm2 (Valo X), although the PinkWave delivered 32.1 J/cm2 in 20 s 350 to 900 nm. All four RBCs achieved their maximum DC and VH values at the bottom when photo-cured for 20 s. The Monet used for 1 s and the PinkWave used for 3 s on the Boost setting delivered the lowest radiant exposures between 420 and 500 nm (5.3 J/cm2 and 3.5 J/cm2 respectively), and they produced the lowest DC and VH values. CONCLUSIONS Despite delivering a high irradiance, the short 1 or 3-s exposures delivered less energy to the RBC than 20-s exposures from LCUs that deliver> 1000 mW/cm2. There was an excellent linear correlation (r > 0.98) between the DC and the VH at the bottom. There was a logarithmic relationship between the DC and the radiant exposure (Pearson's r = 0.87-97) and between the VH and the radiant exposure (Pearson's r = 0.92-0.96) delivered in the 420-500 nm range.
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Affiliation(s)
- Cristiane Maucoski
- Department of Restorative Dentistry, State University of Ponta Grossa, Ponta Grossa, Parana, Brazil; Department of Dental Clinical Sciences, Dalhousie University, Faculty of Dentistry, Halifax, Nova Scotia, Canada
| | - Richard Bengt Price
- Department of Dental Clinical Sciences, Dalhousie University, Faculty of Dentistry, Halifax, Nova Scotia, Canada.
| | - Mateus Garcia Rocha
- Department of Restorative Dental Science, Center of Dental Biomaterials College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Jean-François Roulet
- Department of Restorative Dental Science, Center of Dental Biomaterials College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Braden Sullivan
- Department of Restorative Dentistry, State University of Ponta Grossa, Ponta Grossa, Parana, Brazil
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Mechanical and Biomimetic Characteristics of Bulk-Fill Resin Dental Composites Following Exposure in a Simulated Acidic Oral Environment. Biomimetics (Basel) 2023; 8:biomimetics8010019. [PMID: 36648805 PMCID: PMC9844310 DOI: 10.3390/biomimetics8010019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 12/30/2022] [Accepted: 12/31/2022] [Indexed: 01/05/2023] Open
Abstract
During the last 10 years, various companies have marketed different "bulk-fill" resin dental composites for the restoration of posterior stress-bearing teeth; however, the impact of acidic conditions on these relatively newer materials has not been thoroughly investigated. Therefore, an attempt was made to evaluate the effect of acidic beverages on the mechanical biomimetic characteristics of four bulk-fill and one conventional nanohybrid resin-based dental composites (RBCs). The specimens of each RBC were stored in two acidic beverages namely 'Orange Juice' and 'Coca-Cola', whereas 'dry' and 'distilled water' storage of specimens served as controls. After 1 week of storage, flexural and surface hardness properties of specimens were determined using a universal testing machine and Vickers hardness tester, respectively. In general, the 'Coca-Cola' beverage caused the greatest degradation of flexural strength, flexural modulus, and surface hardness characteristics in all RBCs in contrast to the 'dry', 'distilled water' controls and 'Orange Juice' storage conditions. However, the overall mechanical biomimetic performance of nanohybrid RBCs was relatively better than all other bulk-fill RBCs and may, therefore, be considered a suitable candidate for the restoration of posterior stress-bearing permanent dentition.
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AYAZ EAYDOĞAN, ALADAĞ SÜSTÜN. Effect of cigarette smoke and denture cleansers on the surface properties and color stability of CAD-CAM and conventional denture base resins. Dent Mater J 2023; 42:167-176. [PMID: 36476683 DOI: 10.4012/dmj.2022-117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This study aimed to evaluate the hardness, roughness, and color stability of heat- and microwave-polymerized polymethyl methacrylate (PMMA), polyamide, and CAD-CAM PMMA resins when exposed to cigarette smoke (CS) and immersed in a denture cleanser (DC). Specimens of each resins were divided into four subgroups (n=10). The DC and CS+DC specimens were immersed in a DC; the CS and CS+DC specimens were exposed to CS; and the control (C) specimens were kept in distilled water. Hardness, roughness, and color measurements were performed. DC and CS significantly affected the roughness and color of all resins (p<0.05). However, these did not affect the hardness of the CAD-CAM PMMA resin (p>0.05). The CAD-CAM PMMA resin presented the lowest roughness, highest hardness, and lowest ΔE00 values. While the roughness of all resins exposed to CS when immersed in DC decreased, the ΔE00 values of the conventional PMMAs also decreased. Although this decreases were not significant, it may be advisable to use DC for smokers to decrease discoloration and roughness especially for conventional PMMAs resins.
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Affiliation(s)
- Elif AYDOĞAN AYAZ
- Department of Prosthodontics, Faculty of Dentistry, Karadeniz Technical University
| | - Seda ÜSTÜN ALADAĞ
- Department of Prosthodontics, Faculty of Dentistry, Bursa Uludağ University
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Berto-Inga J, Santander-Rengifo F, Ladera-Castañeda M, López-Gurreonero C, Castro Pérez-Vargas A, Cornejo-Pinto A, Cervantes-Ganoza L, Cayo-Rojas C. Surface Microhardness of Bulk-Fill Resin Composites Handled With Gloves. Int Dent J 2022:S0020-6539(22)00231-3. [DOI: 10.1016/j.identj.2022.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 10/14/2022] [Accepted: 10/14/2022] [Indexed: 11/19/2022] Open
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Gazzani F, Bellisario D, Quadrini F, Danesi C, Alberti A, Cozza P, Pavoni C. Light-curing process for clear aligners' attachment reproduction: comparison between two nanocomposites cured by the auxiliary of a new tool. BMC Oral Health 2022; 22:376. [PMID: 36064526 PMCID: PMC9442987 DOI: 10.1186/s12903-022-02407-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 08/23/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Attachments' configuration play an important role during Clear Aligner Treatment (CAT) for aligner retention and control of movements planned. The aims were to compare the macroscopic morphology of attachments reproduced with flowable (FNC) and conventional (CNC) composites and the effects on them of two light-guide tips with different dimensions. METHODS 4 resin casts derived from the initial scan of the same patient were obtained. 10 vestibular attachments were replaced on both upper and lower arches of each model with CNC (Models A, B) and FNC (Models C, D). Each composite was cured by means of the same LED lamp with both regular light-guide (Models A, B) and push and light tool® (Models C, D). The 80 attachments were qualitative analyzed by means of a digital stereo microscope. Surface roughness and waviness measurements were assessed by contact probe surface profiler (TalySurf CLI 2000; Taylor Hobson, Leicester, United Kingdom). Statistical analysis was performed with independent samples t-tests. Significance was established at the P < 0.05 level. RESULTS Model A showed lower values of surface roughness (Ra - 1.41 µm, Rt - 3.46 µm) and waviness (Wa - 2.36 µm, Wt - 10.95 µm) when compared with Model C. Significant reduction of waviness (Wa - 3.85 µm, Wt - 4.90 µm) was observed on Model B when compared with Model D. Significant increase of roughness and waviness parameters (Ra 3.88 µm, Rt 21.07, Wa 2.89 µm, Wt 14.74 µm) was found when CNC sample (Model A) was cured with regular light-guide tip. Higher values (Ra 2.33 µm, Rt 24.07 µm, Wa 1.67 µm, Wt 20.79 µm) were observed after regular light-guide tips curing on FNC sample (Model C). CONCLUSIONS CNC resins determine more regular surfaces of attachments profiles. The additional use of a smaller light- guide of the LED push and light tool® allows to improve the macroscopic morphology of the attachments and to maximize light irradiance delivering by enhancing the polymerization process and the integrity of the features during the treatment.
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Affiliation(s)
- Francesca Gazzani
- Department of Systems Medicine, University of Rome 'Tor Vergata', Viale Oxford 81, 00133, Rome, Italy.
| | - Denise Bellisario
- Department of Industrial Engineering, University of Rome 'Tor Vergata', Rome, Italy
| | - Fabrizio Quadrini
- Department of Industrial Engineering, University of Rome 'Tor Vergata', Rome, Italy
| | - Carlotta Danesi
- Department of Systems Medicine, University of Rome 'Tor Vergata', Viale Oxford 81, 00133, Rome, Italy
| | - Andrea Alberti
- UniCamillus International Medical University, Rome, Italy.,Department of Dentistry, UNSBC, Tirana, Albania
| | - Paola Cozza
- Department of Systems Medicine, University of Rome 'Tor Vergata', Viale Oxford 81, 00133, Rome, Italy.,Department of Dentistry, UNSBC, Tirana, Albania.,Department of Faculty of Medicine and Surgery, UniCamillus International Medical University, Rome, Italy
| | - Chiara Pavoni
- Department of Systems Medicine, University of Rome 'Tor Vergata', Viale Oxford 81, 00133, Rome, Italy.,Department of Dentistry, UNSBC, Tirana, Albania.,Department of Faculty of Medicine and Surgery, UniCamillus International Medical University, Rome, Italy
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Investigating the Cytotoxicity of Dual-Cure Bulk-Fill Resin Materials on L929 Cells. PROSTHESIS 2022. [DOI: 10.3390/prosthesis4030036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The aim of this in vitro study was to investigate cytotoxic effects of dual-cure bulk-fill resin materials polymerized with a third-generation LED light-curing unit (LCU) on L929 fibroblast cells in terms of morphology and viability. Three novel dual-cure, flowable bulk-fill materials (Fill-Up!™), a bioactive material (ACTIVA™ BioACTIVE-RESTORATIVE™), and a dual-cure bulk-fill composite material (HyperFIL® HAp) polymerized by LED LCU (VALO™ Cordless) were tested. Each material was placed in plastic rings (4 mm × 5 mm) in a single layer. Unpolymerized rings filled with each material were placed in direct contact with cells and then polymerized. After polymerization, the removed medium was readded to wells. In this study, four control groups were performed: the medium-free control group, medium control group, physical control group, and light applied control group. Three samples were prepared from each group. After 24 h, the morphology of cells was examined and a WST-1 test was performed. The percentage of cell viability (PCV) of each group was calculated. The experiment was repeated three times. Data were analyzed by a Kruskal–Wallis Test and a Mann–Whitney U test. p < 0.05 was considered significant. The PCV of all groups were found to be significantly lower than the medium control group (p < 0.05). The lowest PCV was obtained in HyperFIL® Hap, while highest was in the Fill-Up!™. In the morphology of cells related to the experimental groups, it was observed that the spindle structures of cells were disrupted due to cytotoxicity; cells became rounded and intercellular space increased. There were no significant differences between the control groups (p > 0.05). All control groups showed acceptable PCV (>70%) and cells were spindle-like, similar to the original fibroblast cells. It can be suggested that clinicians should pay attention when applying dual-cure bulk-fill materials in deep cavities, or they should use a liner material under these materials.
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David C, Cuevas-Suárez CE, de Cardoso GC, Isolan CP, de Moraes RR, da Rosa W, Münchow EA, da Silva AF. Characterization of Contemporary Conventional, Bulk-fill, and Self-adhesive Resin Composite Materials. Oper Dent 2022; 47:392-402. [PMID: 35917238 DOI: 10.2341/21-063-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2021] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To evaluate the physical and biological properties of different types of flowable resin composites and their bonding ability to dentin, comparing the performance of self-adhesive and bulk-fill materials with a conventional control. METHODS AND MATERIALS Four flowable resin composites were tested: two self-adhesive (Y-flow [SA_YF]; and Dyad Flow [SA_DF]); one bulk-fill (Filtek Bulk Fill Flow [BF]); and one conventional composite (Opallis Flow [OF]). The microshear bond strength (μSBS) to dentin (bovine samples) was investigated at 24 hours and 6 months of storage. The materials were also characterized by degree of conversion, cross-link density, water contact angle, color stability, and cell viability (ISO 10993-5/2009) analyses. Data were analyzed using Analysis of Variance and Tukey tests (α=0.05). RESULTS The μSBS values were higher for control specimens at 24 hours, whereas the resin-dentin bonds were similarly distributed among the groups after aging. Adhesive failure was the most frequent pattern observed at both time intervals. SA_YF was the only material that increased the bond strength over time. Degree of conversion increased in the following order: SA_YF (28.6±1.4%) < BF (49.7±0.8%) < OF (60.0±2.0%) = SA_DF (63.6±2.3%). Cross-link density was similar among all materials. The self-adhesive composites were more hydrophilic than the other types, with BF showing the lowest water contact angle and the greatest color alteration. All resin composites had a biocompatible behavior. CONCLUSION Chemical composition appeared to be an influential factor affecting the physicomechanical and biological behavior of the materials tested.
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Affiliation(s)
- C David
- Carla David, Biopathological Research Group, Faculty of Dentistry (GIBFO), University of the Andes Mérida, Mda, Venezuela; Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, RS, Brazil
| | - C E Cuevas-Suárez
- Carlos Enrique Cuevas-Suárez, Dental Materials Laboratory, Academic Area of Dentistry, Autonomous University of Hidalgo State, Pachuca, Hgo, Mexico
| | - G C de Cardoso
- Gabriela Cardoso de Cardoso, Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, RS, Brazil
| | - C P Isolan
- Cristina Pereira Isolan, Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, RS, Brazil
| | - R R de Moraes
- Rafael Ratto de Moraes, Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Wlo da Rosa
- Wellington Luiz Oliveira da Rosa, Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, RS, Brazil
| | - E A Münchow
- Eliseu A Münchow, Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul, POA, RS, Brazil
| | - A F da Silva
- *Adriana Fernandes da Silva, Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, RS, Brazil
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15
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Gilli M, Hollaert TG, Setbon HM, des Rieux A, Leprince JG. Quality of Cure in Depth of Commercially Available Bulk-fill Composites: A Layer-by-layer Mechanical and Biological Evaluation. Oper Dent 2022; 47:437-448. [PMID: 35917249 DOI: 10.2341/21-084-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2021] [Indexed: 11/23/2022]
Abstract
Despite their popularity, the use of bulk-fill composites remains controversial, both in terms of their properties and their in-depth development. The objectives of the present work were (1) to provide a more comprehensive evaluation of the quality of cure in depth of commercially available bulk-fill composites by combining various key mechanical and biological characterization methods, (2) to evaluate the inter-material differences when optimally cured, and (3) to evaluate the efficiency of an antioxidant-N-acetyl-cysteine (NAC)-to restrain the adverse effects of the leached components on cell viability. Nine bulk-fill composites (including flowable and high-viscosity materials) were investigated and compared to two conventional resin-based composites, one flowable and one high-viscosity restorative material. The materials were injected or packed into Teflon molds of various configurations, up to 6 mm material thickness. They were then light-cured from the top for 20 seconds with Bluephase G2 (Ivoclar Vivadent, irradiance = 1050 mW/cm2). The following physicomechanical properties were measured for the upper (0-2 mm), intermediate (2-4 mm), and lower (4-6 mm) layers: degree of conversion using Raman Spectrometry (DC, in %), microhardness using a Vickers micro-indenter before (VHN dry) and after 24 hours of storage in ethanol (VHN EtOH), and flexural strength (in MPa) and flexural modulus (in GPa) using a three-point bend test. Each composite layer and an uncured layer were also stored for one week in a standard cell growth medium to generate conditioned media. Human dental pulp cells were then cultured for 24 hours with the latter and cell viability was measured using an MTS assay. A similar experiment was repeated with conditioned media produced in contact with uncured composites, with and without the addition of 4 mM NAC. The data were subjected to a Shapiro-Wilk test, then one-way ANOVA or Kruskal-Wallis test, followed either by Tukey's test (inter-material comparison) or by Dunnett's or Dunn's test (comparison between layers relative to the upper one). The level of statistical significance was set at 0.05. Some materials (EverX, X-traF, VenusBF, X-traB) did not show any significant differences (p>0.05) for any of the properties considered between the intermediate layers compared to the upper one (considered as reference). Others displayed significant differences, at least for some properties, highlighting the value of combining various key mechanical and biological characterization methods when investigating the quality of cure in depth. Significant inter-material differences (p<0.05) were observed when comparing the properties of their upper layer, considered as "optimally" polymerized. Hence, one needs to consider the absolute property values, not only their relative evolution concerning layer thickness. Finally, the use of NAC appeared as beneficial to reduce the risk of harmful effects to dental pulp cells, especially in case of excessive thickness use, and may therefore be of potential interest as an additive to composites in the future.
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Affiliation(s)
- M Gilli
- *Matthieu Gilli, Adult and Child Dentistry, Cliniques Universitaires Saint-Luc, Brussels, Belgium; DRIM Research Group & Advanced Drug Delivery and Biomaterials, Louvain Drug Research Institute, UCLouvain, Brussels, Belgium
| | - T G Hollaert
- Thibaut G Hollaert, Adult and Child Dentistry, Cliniques Universitaires Saint-Luc, Brussels, Belgium; DRIM Research Group & Advanced Drug Delivery and Biomaterials, Louvain Drug Research Institute, UCLouvain, Brussels, Belgium
| | - H M Setbon
- Hugo M Setbon, private practice; DRIM Research Group & Advanced Drug Delivery and Biomaterials, Louvain Drug Research Institute, UCLouvain, Brussels, Belgium
| | - A des Rieux
- Anne des Rieux, DRIM Research Group & Advanced Drug Delivery and Biomaterials, Louvain Drug Research Institute, UCLouvain, Brussels, Belgium
| | - J G Leprince
- Julian G. Leprince, Adult and Child Dentistry, Cliniques Universitaires Saint-Luc, Brussels, Belgium; DRIM Research Group & Advanced Drug Delivery and Biomaterials, Louvain Drug Research Institute, UCLouvain, Brussels, Belgium
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Soto-Montero J, de Castro EF, Romano BDC, Nima G, Shimokawa CAK, Giannini M. Color alterations, flexural strength, and microhardness of 3D printed resins for fixed provisional restoration using different post-curing times. Dent Mater 2022; 38:1271-1282. [PMID: 35717230 DOI: 10.1016/j.dental.2022.06.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 06/06/2022] [Accepted: 06/06/2022] [Indexed: 11/03/2022]
Abstract
OBJECTIVES To evaluate the effect of post-curing times on the color change, flexural strength (FS), modulus (FM) and microhardness at different depths of four 3D printed resins. MATERIALS AND METHODS A characterization of the light emitted by 3D-resin post-curing unit (Wash and Cure 2.0, Anycubic) was performed. The tested 3D printed resins were Cosmos Temp3D (COS), SmartPrint BioTemp (SM) Resilab3D Temp (RES) and Prizma3D BioProv (PRI) were evaluated under five different post-curing conditions (no post-curing or 5-, 10-, 15, and 20 min of post-curing). For color change analysis, 10 mm diameter x 1 mm thick discs (n = 7) were printed, and the luminosity, color and translucency were measured before post-curing as control, and repeatedly after 5 min cycles of post-curing until a total of 20 min was reached for ΔE00 [CIED2000 (1:1:1)] calculation. For FS and FM, 25 × 2×2 mm (n = 10, for each post-curing time) 3D printed bars were subjected to a 3-point being test. Knoop microhardness (KHN) was measured transversally on 5 × 5×5 mm blocks (n = 10, for each post-curing time). Color results were analyzed by one-way repeated measures ANOVA (factor: color change). FS and FM were analyzed by two-way ANOVA (factors: Material*Post-Curing Time). KHN was analyzed individually for each material by two-way ANOVA (factors: Depth*Post-Curing Time). RESULTS The post-curing time significantly influenced the ΔE00, FS, FM and KHN of all the evaluated materials. COS and SMA presented ΔE00 values above the acceptability threshold after 5 and 10 min of post-curing, respectively. The FS of RES reached a plateau after 5 min of post-curing, and for PRI and SMA, the FS stabilized after 10 min of post-curing. The post-curing process improved the KHN of the tested materials, and longer exposure periods were associated to higher KHN values at all the evaluated depths. SIGNIFICANCE A fine adjustment of the post-curing time is crucial to produce adequate mechanical properties in 3D-printed restorative resins, while minimizing the color alterations on the restorations. For the evaluated resins, 5-10 min of post-curing will result in adequate mechanical properties, without affecting the acceptability in the color of the material. However, the results are material-dependent, and evaluation of each specific resin is advised.
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Affiliation(s)
- Jorge Soto-Montero
- Department of Restorative Dentistry, School of Dentistry, Universidad de Costa Rica, Montes de Oca, SJ, Costa Rica.
| | - Eduardo F de Castro
- Department of Restorative Dentistry, Operative Dentistry Division, Piracicaba Dental School, Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | - Beatriz de C Romano
- Department of Restorative Dentistry, Operative Dentistry Division, Piracicaba Dental School, Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | - Gabriel Nima
- School of Dentistry, Universidad Científica del Sur, Lima, Perú
| | - Carlos A K Shimokawa
- Department of Restorative Dentistry, School of Dentistry, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Marcelo Giannini
- Department of Restorative Dentistry, Operative Dentistry Division, Piracicaba Dental School, Universidade Estadual de Campinas, Piracicaba, SP, Brazil
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Wolf TG, Dekert N, Campus G, Ernst CP. White-opaque flowable composite liner as a depth marker in composite restorations prevents tooth substance loss in filling removal: a randomized double-blinded in vitro study. Clin Oral Investig 2022; 26:2711-2717. [PMID: 34714398 PMCID: PMC8898228 DOI: 10.1007/s00784-021-04244-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/18/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Removal of esthetic restorations leads to loss of tooth structure and the extent of the loss is difficult to estimate due to exact-shade matching. This randomized double-blinded in vitro study aimed examining the influence of a white-opaque flowable composite depth marker as an optical removal aid for tooth substance preservation and shortened restoration removal time. MATERIALS AND METHODS Class II cavities (n = 100) in extracted healthy mandibular molars (n = 50, two runs) were prepared, filled, and the restoration removed. Tooth weight and volume (before and after) and removal time were measured and remnants visually documented. An optimal tooth shade-matched flowable composite liner was used as control. RESULTS Tooth structure loss was significantly lower using a white-opaque liner. Mean values for volume/weight loss were 0.037 ± 0.030 g and 0.016 ± 0.005 cm3 (p < 0.01) for white-opaque liner; 0.067 ± 0.000 g and 0.028 ± 0.003 cm3 (p < 0.01) for tooth-colored composite. Removal time and number of pulp chamber perforations showed no significant differences (p = 0.80). CONCLUSIONS Within the limitations of this randomized double-blinded in vitro study, the use of a white-opaque flowable liner as a depth marker may provide the practitioner a visual aid in the replacement of a composite restoration and may protect against tooth structure loss. CLINICAL RELEVANCE When restoration replacement is indicated, removal of esthetic restorations often causes tooth structure loss due to difficult optical color matching. Using a white-opaque flowable liner as a depth marker clinically aids in restoration removal and protects against tooth structure loss.
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Affiliation(s)
- Thomas Gerhard Wolf
- Department of Restorative, Preventive and Pediatric Dentistry, School of Dental Medicine, University of Bern, Freiburgstrasse 7, CH-3010, Bern, Switzerland.
- Department of Periodontology and Operative Dentistry, University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany.
| | - Natalie Dekert
- Department of Periodontology and Operative Dentistry, University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Guglielmo Campus
- Department of Restorative, Preventive and Pediatric Dentistry, School of Dental Medicine, University of Bern, Freiburgstrasse 7, CH-3010, Bern, Switzerland
- Department of Surgery, Microsurgery and Medicine Sciences, School of Dentistry, University of Sassari, Sassari, Italy
- Department of Pediatric, Prophylaxis Dentistry and Orthodontics, School of Dentistry, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Claus-Peter Ernst
- Department of Periodontology and Operative Dentistry, University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany
- medi+ Zahnärztliche Praxisklinik, Mainz, Germany
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Rocha MG, Oliveira DCRSD, de Menezes LR, Roulet JF, Sinhoreti MAC, Correr AB. The use of an elastomeric methacrylate monomer (Exothane 24) to reduce the polymerization shrinkage stress and improve the two-body wear resistance of bulk fill composites. Dent Mater 2021; 38:e43-e57. [PMID: 34953625 DOI: 10.1016/j.dental.2021.12.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 11/03/2022]
Abstract
OBJECTIVES Characterize the chemical structure of an elastomeric monomer (Exothane 24) and evaluate the degree of conversion (DC), polymerization shrinkage stress (PSS), rate of polymerization (Rp), flexural strength (FStrenght), flexural modulus (FModulus), Vickers hardness (VHardness) and two-body wear resistance of dental bulk fill composites (BFCs) containing Exothane 24. METHODS The Exothane 24 was characterized using mass spectroscopy, elemental analysis, 13C- and 1H NMR. BFCs were formulated containing Exothane 24 (E10, E25, and E50). Similar BFCs containing regular UDMA (U10, U25, and U50), commercial conventional, and BFCs were used as control groups. ATR-FTIR spectroscopy was used to measure DC and the Rp of the composites. The PSS was measured using the universal testing machine method. Specimen bars were used to assess the FStrenght, FModulus, and VHardness. RBCs were submitted to a two-body wear test using a chewing simulator machine; the rate and volumetric wear loss were evaluated using an optical scanner. Data were analyzed statistically with α = 0.05 and β = 0.2. RESULTS Exothane 24 is a urethane isophorone tetramethyl methacrylate monomer with polymerization stress-relieving properties. No differences were found in the DC up to 4 mm in depth for E25. All BFCs had similar FStrenght, except for E50. E25 had the lowest volumetric wear loss and wear rate. E25 had approximately 30% lower PSS and slower Rp than commercial BFCs with similar wear resistance to conventional commercial composites. SIGNIFICANCE The Exothane 24 reduced the PSS and increased the wear resistance of BFCs; however, the formulation is important to optimize the properties of the BFCs.
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Affiliation(s)
- Mateus Garcia Rocha
- Center for Dental Biomaterials, Department of Restorative Dental Sciences, College of Dentistry, University of Florida, Gainesville, FL, USA.
| | | | - Livia Rodrigues de Menezes
- Institute of Macromolecules Professor Eloisa Mano, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Jean-François Roulet
- Center for Dental Biomaterials, Department of Restorative Dental Sciences, College of Dentistry, University of Florida, Gainesville, FL, USA
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Effect of extended light activation and increment thickness on physical properties of conventional and bulk-filled resin-based composites. Clin Oral Investig 2021; 26:3141-3150. [PMID: 34826031 DOI: 10.1007/s00784-021-04296-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 11/11/2021] [Indexed: 10/19/2022]
Abstract
OBJECTIVES To evaluate the biaxial flexural strength (BFS), flexural modulus (BFM), and Knoop microhardness (KHN) of incremental and bulk-filled resin-based composites (RBCs) using extended curing exposure times. MATERIALS AND METHODS Disc specimens (n = 8; 6-mm diameter) were fabricated using three stacked molds (0.5-mm thick for the top and bottom molds, and a 1-mm-thick center mold for the conventional and 3-mm thick for the bulk-fill RBCs). Conventional (Tetric EvoCeram/TCE and Filtek Z250/FIZ) and bulk-fill RBCs (Tetric EvoCeram Bulk Fill/TBF and Filtek One Bulk Fill Restorative/FOB) were evaluated. The stacked RBC-filled molds were light-cured for (1) the manufacturer-recommended exposure (MRE) duration; (2) 50%, and (3) 100% extension of the MRE. The BFS, BFM, and KHN of the top and bottom discs were measured. BFS and BFM were analyzed by three-way ANOVA (material*curing time*depth) and Tukey's post hoc (α = 0.05). KHN was analyzed by two-way ANOVA (curing time*depth) and Tukey's post hoc (α = 0.05). RESULTS Extending the exposure duration did not change the BFS and BFM on the top of the RBCs, but the BFS and KHN increased at the bottom of bulk-fill RBCs. For the conventional RBCs, TCE showed the highest increase on BFS at the bottom, going from 53.6 MPa at T1 to 69.9 at T3. Among the bulk-fill RBCs, FOB presented the highest increase on the bottom BFS (T1: 101.0 ± 19.9 MPa, T3: 147.6 ± 12.9 MPa). For all RBCs and exposure times, BFS and KHN were lower at the bottom. Only FIZ and FOB reached a bottom-to-top hardness ratio of 80%, at T3 and T2. CONCLUSION A significant increase on the BFS and KHN on the bottom of bulk-fill RBCs can be observed when the time of exposure to the curing light is double the MRE. However, extended exposure does not eliminate differences on the BFS and KHN between the shallow and deep regions of RBCs. TCE and TBF failed to reach an acceptable B/T hardness ratio at all evaluated exposure times. CLINICAL RELEVANCE Mechanical properties of RBCs can be affected by insufficient polymerization, specially at deeper regions of the increment. Therefore, clinicians should consider applying twice the MRE to curing-light to polymerize the maximal increment thickness of bulk-fill RBCs.
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Improper Light Curing of Bulkfill Composite Drives Surface Changes and Increases S. mutans Biofilm Growth as a Pathway for Higher Risk of Recurrent Caries around Restorations. Dent J (Basel) 2021; 9:dj9080083. [PMID: 34435995 PMCID: PMC8394739 DOI: 10.3390/dj9080083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 07/15/2021] [Accepted: 07/26/2021] [Indexed: 01/10/2023] Open
Abstract
How dentists cure a resin-based material has deleterious effects on the material's properties and its interaction with surrounding dental tissues. Biofilm accumulation has been implicated in the pathogenesis of carious lesions around dental restorations, with its composition manifesting expressed dysbiosis in patients suffering from dental caries. To evaluate the influence of varying radiant exposure on the degree of conversion (DC%), Streptococcus mutans biofilm growth, and surface roughness of bulk-fill composites under different light-curing conditions. Two light-curing units (LCU) at 600 and 1000 mW/cm2 were used to simulate curing conditions with different angulations (∢20° and ∢35°) or 2 mm-distance displacements of the LCU tip. The radiant exposure (RE) was assessed, and the composites were analyzed for DC%. Biofilm formation was induced over the bulk-fill composites and analyzed via colony-forming units counting and scanning electron microscopy (SEM). The surface roughness was analyzed via a profilometer and SEM after biofilm formation. Curing conditions with different angulation or displacement decreased RE compared to the "optimal condition". The moderately (∢35°) angulated LCU tip and low (600 mW/cm2) radiant emittance significantly reduced the DC% (p < 0.05). The difference in DC% between the top and bottom of the composites ranged from 8 to 11% for 600 mW/cm2 and 10 to 20% for 1000 mW/cm2. Greater S. mutans biofilm and surface changes were found in composites with non-optimal RE delivery (e.g., tip displacement and angulation) (p < 0.05). Inadequate polymerization of bulk-fill composites was associated with more biofilm accumulation and surface topography changes. Overall, non-optimally performed curing procedures reduced the amount of delivered RE, which led to low DC%, more biofilm formation, and higher surface roughness. The improper light-curing of bulk-fill composites compromises their physicochemical and biological properties, which could lead to inferior clinical performance and reduced restorative treatments' longevity.
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Sword RJ, Bachand W, Mears B, Quibeuf L, Looney S, Price RB, Rueggeberg FA. Effect of Operator Experience on Ability to Place Sequential, 2-mm-thick Increments of Composite. Oper Dent 2021; 46:327-338. [PMID: 34143219 DOI: 10.2341/19-286-l] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2020] [Indexed: 11/23/2022]
Abstract
Because an operator has only about one chance out of three to place a composite increment within this clinically acceptable range, clinicians are advised to use an instrument (e.g., a periodontal probe with a 2-mm mark) to estimate the thickness of each increment of composite they place. SUMMARY Objective: To measure and compare the effect of operator experience in their ability to place composite in increments that are 2 mm thick.Methods and Materials: Fifteen volunteers from each class of freshmen, sophomores, juniors, and senior dental students and 15 clinical faculty (total number of volunteers = 75) were asked to restore a Class I preparation that was 5 mm in diameter and 8 mm deep from the cusp tips using three increments of composite that were each to be 2 mm thick. Once completed, the models were sectioned, and the thickness of each increment was measured. A repeated-measures analysis of variance (pre-set α=0.05) was used to compare the mean increment thickness with respect to operator experience level and increment sequence number. In addition, the proportion of operators placing clinically acceptable increments (between 1.75 and 2.25 mm thick), as well as the proportions from each group who placed increments that either were thinner or thicker than this range, was determined using nonparametric analyses.Results: Overall, there was an increasing trend for groups with a higher experience level to provide mean incremental thickness values close to 2 mm. However, the likelihood of placing an increment that was thicker or thinner than the manufacturer-recommended thickness was not significantly different. Regardless of the increment value, only about one-third of the increments placed fell within the desired range of 1.75 to 2.25 mm.Conclusions: Operator experience had no overwhelming significant influence on the ability to place increments of composite that were between 1.75 and 2.25 mm thick. An operator has only about one chance out of three to place a composite increment within this clinically acceptable range when using no external measurement system.
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22
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Martins ARM, Silva ID, Machado‐Santos L, Vitti RP, Sinhoreti MAC, Brandt WC. Isobornyl methacrylate as diluent co‐monomer on physical‐mechanical properties of dental resin composites. J Appl Polym Sci 2021. [DOI: 10.1002/app.50498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Aurealice Rosa Maria Martins
- Department of Restorative Dentistry, Piracicaba Dental School University of Campinas Piracicaba São Paulo Brazil
| | - Isaias Donizeti Silva
- School of Dentistry, Implantology Area Santo Amaro University São Paulo São Paulo Brazil
| | - Luciana Machado‐Santos
- Department of Prosthodontics, School of Dentistry University of Taubaté Taubaté São Paulo Brazil
| | - Rafael Pino Vitti
- School of Dentistry Herminio Ometto University Center Araras São Paulo Brazil
| | | | - William Cunha Brandt
- School of Dentistry, Implantology Area Santo Amaro University São Paulo São Paulo Brazil
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23
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Blum IR, Martos R, Szalóki M, Lynch CD, Hegedűs C. Effects of different surface treatments and adhesive self-etch functional monomers on the repair of bulk fill composites: A randomised controlled study. J Dent 2021; 108:103637. [PMID: 33766513 DOI: 10.1016/j.jdent.2021.103637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/07/2021] [Accepted: 03/09/2021] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVE To evaluate the effect of different adhesive protocols on the microtensile bond strength (μTBS) and integrity of the repaired bulk fill composite interface. METHODS Two hundred and seventy composite blocks made of bulk fill composites of different viscosity were randomly assigned to 18 surface conditioning groups (n = 15/group). The universal adhesive systems used were Heliobond™, Tokuyama bond force II™ and Scotchbond Universal™. A nanohybrid resin composite was applied as the repair material. Negative and positive control groups were included. Stick shape specimens of each group were subjected to μTBS testing. Representative samples from all test groups were subjected to microscopic, profilometric and SEM examination to determine their mode of failure. The data were analysed statistically using two-way ANOVA test, Tukey's test and the independent t-test (α = 0.05). RESULTS The mean μTBS of all test groups ranged between 28.5 and 46.8 MPa and varied with the type of adhesive system employed. Significantly highest μTBS values were obtained when Tokuyama bond force II™ and Scotchbond Universal™ adhesives were used (p < 0.01) which were comparable to the coherent strength of the bulk fill resin composite in the positive control groups (p > 0.05). The viscosity of the bulk fill composite did not significantly influence repair bond strength. The microscopy and SEM examination of the failed interfaces revealed a mixture of adhesive and cohesive failures. CONCLUSIONS Under the tested conditions, significantly greater μTBS of repaired bulk fill composite was achieved when the substrate surface was treated with adhesive systems containing a functional monomer. CLINICAL SIGNIFICANCE Eff ;ecting a repair of a bulk fill resin composite restoration with the application of a functional monomer containing adhesive system, such as Tokuyama Bond Force II™ or Scotchbond Universal™, would seem to enhance the interfacial bond strength and integrity of the repaired resin composite interface.
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Affiliation(s)
- Igor R Blum
- Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London, United Kingdom.
| | - Renáta Martos
- Department of Restorative Dentistry, Faculty of Dentistry, University of Debrecen, Nagyerdei krt. 98., H4032, Debrecen, Hungary.
| | - Melinda Szalóki
- Department of Biomaterials and Prosthetic Dentistry, Faculty of Dentistry, University of Debrecen, Nagyerdei krt. 98., H4032, Debrecen, Hungary.
| | - Christopher D Lynch
- Department of Restorative Dentistry, University Dental School and Hospital, University College Cork, Wilton, Cork Ireland, Ireland.
| | - Csaba Hegedűs
- Department of Biomaterials and Prosthetic Dentistry, Faculty of Dentistry, University of Debrecen, Nagyerdei krt. 98., H4032, Debrecen, Hungary.
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24
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Ebner C, Mitterer J, Gonzalez-Gutierrez J, Rieß G, Kern W. Resins for Frontal Photopolymerization: Combining Depth-Cure and Tunable Mechanical Properties. MATERIALS 2021; 14:ma14040743. [PMID: 33562577 PMCID: PMC7914558 DOI: 10.3390/ma14040743] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 01/28/2021] [Accepted: 02/02/2021] [Indexed: 11/28/2022]
Abstract
Photopolymerization has undergone significant development in recent years. It enables fast and easy processing of materials with customized properties and allows precise printing of complex surface geometries. Nevertheless, photopolymerization is mainly applied to cure thin films since the low curing depth limits the fast production of large volumes. Frontal photopolymerization (FPP) is suitable to overcome these limitations so that curing of centimeter-thick (meth)acrylic layers can be accomplished within minutes by light induction only. Prerequisites, however, are the low optical density of the resin and bleaching ability of the photoinitiator. To date, tailored FPP-resins are not commercially available. This study discusses the potential of long-chain polyether dimethacrylates, offering high-temperature resistance and low optical density, as crosslinkers in photobleaching resins and investigates the mechanical properties of photofrontally-cured copolymers. Characteristics ranging from ductile to hard and brittle are observed in tensile tests, demonstrating that deep curing and versatile material properties are achieved with FPP. Analyzed components display uniform polymerization over a depth of four centimeters in Fourier transform infrared spectroscopy and swelling tests.
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Affiliation(s)
- Catharina Ebner
- Department of Polymer Engineering and Science, Chair in Chemistry of Polymeric Materials, University of Leoben, 8700 Leoben, Austria; (C.E.); (J.M.); (W.K.)
| | - Julia Mitterer
- Department of Polymer Engineering and Science, Chair in Chemistry of Polymeric Materials, University of Leoben, 8700 Leoben, Austria; (C.E.); (J.M.); (W.K.)
| | - Joamin Gonzalez-Gutierrez
- Department of Polymer Engineering and Science, Chair of Polymer Processing, University of Leoben, 8700 Leoben, Austria;
| | - Gisbert Rieß
- Department of Polymer Engineering and Science, Chair in Chemistry of Polymeric Materials, University of Leoben, 8700 Leoben, Austria; (C.E.); (J.M.); (W.K.)
- Correspondence: ; Tel.: +43-3842-402-2301
| | - Wolfgang Kern
- Department of Polymer Engineering and Science, Chair in Chemistry of Polymeric Materials, University of Leoben, 8700 Leoben, Austria; (C.E.); (J.M.); (W.K.)
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25
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Sandomierski M, Buchwald Z, Buchwald T, Voelkel A. Silica-filled methacrylic composites with extremely high compressive strength. J Mech Behav Biomed Mater 2021; 116:104319. [PMID: 33482591 DOI: 10.1016/j.jmbbm.2021.104319] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 12/10/2020] [Accepted: 01/06/2021] [Indexed: 11/25/2022]
Abstract
SYLOID® 244 has never been applied as a filler in composites with potential dental application. Therefore, the aim of research was to apply this silica in its unmodified and diazonium salt-modified forms in different mass ratios as fillers in light-cured methacrylic composites. The effectiveness of modification process was confirmed with the use of Raman spectroscopy. Methacrylic composites with the modified and unmodified SYLOID® 244, as well as unfilled resin as a control group were prepared. Their basic physicochemical properties, such as depth of cure, mass stability during incubation in saline, flexural and compressive strengths were examined. A positive effect of SYLOID® 244 modification on the properties of the examined composites was also demonstrated. The obtained results proved the high applicability of SYLOID® 244 as a filler in composites with potential dental applications.
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Affiliation(s)
- Mariusz Sandomierski
- Poznan University of Technology, Institute of Chemical Technology and Engineering, ul. Berdychowo 4, 60-965, Poznań, Poland.
| | - Zuzanna Buchwald
- Poznan University of Technology, Institute of Chemical Technology and Engineering, ul. Berdychowo 4, 60-965, Poznań, Poland
| | - Tomasz Buchwald
- Poznan University of Technology, Institute of Materials Research and Quantum Engineering, ul. Piotrowo 3, 60-965, Poznań, Poland
| | - Adam Voelkel
- Poznan University of Technology, Institute of Chemical Technology and Engineering, ul. Berdychowo 4, 60-965, Poznań, Poland
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26
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Gomes de Araújo-Neto V, Sebold M, Fernandes de Castro E, Feitosa VP, Giannini M. Evaluation of physico-mechanical properties and filler particles characterization of conventional, bulk-fill, and bioactive resin-based composites. J Mech Behav Biomed Mater 2020; 115:104288. [PMID: 33383377 DOI: 10.1016/j.jmbbm.2020.104288] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/05/2020] [Accepted: 12/13/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVE This study evaluated physical and mechanical properties and characterized the filler particles of seven composites. MATERIALS AND METHODS Filtek Supreme (FS, 3M Oral Care), Forma (FO, Ultradent), Charisma Diamond (CD, Kulzer), Spectra Smart (SS, Dentsply), Filtek Bulk Fill (FB, 3M Oral Care), Tetric N-Ceram Bulk Fill (TB, Ivoclar), and Cention N (Ivoclar) in self- (CNSC) or dual-curing (CNDC) were evaluated. Fillers size, shape, and content were analyzed by scanning electron microscopy (SEM) and X-ray dispersive energy spectroscopy (EDX). Disk-shaped specimens (n = 5) were prepared for sorption (SP) and solubility (SL). Flexural strength and elastic modulus were tested at 24 h and 12 months (n = 10). Degree of conversion (DC%) and maximum rate of polymerization (Rpmax) were evaluated using micro-Raman spectroscopy. SP and SL results were submitted to Kruskal-Wallis one-way ANOVA and Dunn's pairwise test (α = 0.05). Mechanical properties were analyzed by 2-way ANOVA and Tukey's test (α = 0.05). DC% of CNSC and CNDC was compared by independent t-test (α = 0.05). Rpmax results were analyzed by 1-way ANOVA and Tukey's test (α = 0.05). RESULTS The composites differed regarding filler size, shape, and content. CD and CNSC showed lower SP than FS. SS had lower SL than CNSC and CNDC. CNDC presented higher DC% than CNSC. CD, TB, and CNDC showed the highest Rpmax. TB, CNSC, and CNDC showed the lowest 24-h flexural strengths. Mechanical properties of CD did not decrease, while FO, TB, and CNSC showed a significant reduction after storage. CONCLUSIONS Monomer composition and fillers characteristics greatly influenced the physico-mechanical properties of the tested composites.
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Affiliation(s)
- Vitaliano Gomes de Araújo-Neto
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, University of Campinas, Avenida Limeira, 901, Bairro Areião, Piracicaba, SP, Brazil.
| | - Maicon Sebold
- Department of Restorative Dentistry, Operative Dentistry Division, Piracicaba Dental School, University of Campinas, Avenida Limeira, 901, Bairro Areião, Piracicaba, SP, Brazil.
| | - Eduardo Fernandes de Castro
- Department of Restorative Dentistry, Operative Dentistry Division, Piracicaba Dental School, University of Campinas, Avenida Limeira, 901, Bairro Areião, Piracicaba, SP, Brazil.
| | - Victor Pinheiro Feitosa
- School of Dentistry, Faculty Paulo Picanço, Rua Joaquim Sá, 900, Dionísio Torres, Fortaleza, CE, Brazil.
| | - Marcelo Giannini
- Department of Restorative Dentistry, Operative Dentistry Division, Piracicaba Dental School, University of Campinas, Avenida Limeira, 901, Bairro Areião, Piracicaba, SP, Brazil.
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Bin Nooh AN, Nahedh HA, AlRefeai M, Alkhudhairy F. The Effect of Irradiance on the Degree of Conversion and Volumetric Polymerization Shrinkage of Different Bulk-Fill Resin-Based Composites: An In Vitro Study. Eur J Dent 2020; 15:312-319. [PMID: 33321544 PMCID: PMC8184305 DOI: 10.1055/s-0040-1721236] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Objective
The influence of different light-emitting diode (LED) curing light intensities on the degree of conversion (DC) and volumetric polymerization shrinkage (VPS) of bulk-fill resin-based composite (RBC) restorative materials was evaluated.
Materials and Methods
Twenty-four specimens of each RBC material (Filtek one bulk-fill posterior, Reveal HD Bulk, Tetric N-Ceram, and Filtek Z350) were prepared. The RBCs were shaped in molds and cured using an LED curing light unit at high-intensity (1,200 mW/cm
2
) for 20 seconds and low-intensity (650 mW/cm
2
) for 40 seconds Fourier-transform infrared (FTIR) spectroscopy was used to determine the DC and microcomputed tomography was used to evaluate VPS. Data were analyzed using one- and two-way ANOVA, independent
t
-test, and Tukey’s and Scheffe’s post hoc multiple comparison tests.
Results
With high-intensity curing light, Reveal HD showed the highest DC (85.689 ± 6.811%) and Tetric N-Ceram the lowest (52.60 ± 9.38%). There was no statistical difference in VPS when using high- or low-intensity curing light. The highest VPS was observed for Reveal HD (2.834–3.193%); there was no statistical difference (
p
> 0.05) among the other RBCs.
Conclusion
Curing light intensities do not significantly influence the VPS of RBC materials. Reveal HD bulk cured with high-intensity light had the highest DC.
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Affiliation(s)
- Abrar N Bin Nooh
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Hend Al Nahedh
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Mohammad AlRefeai
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Fahad Alkhudhairy
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia
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28
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Wikant AW, Gedde UW, Hakeberg M, Örtengren UT. Suboptimal light curing and direct exposure to water of two contemporary composites: degree of conversion, sorption, solubility, and Knoop hardness. Eur J Oral Sci 2020; 128:345-353. [DOI: 10.1111/eos.12705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2020] [Indexed: 12/01/2022]
Affiliation(s)
- Aksel W. Wikant
- Department of Clinical Dentistry Faculty of Health Sciences Tromsø University Tromsø Norway
| | - Ulf W. Gedde
- School of Engineering Sciences in Chemistry, Biotechnology and Health, Fibre and Polymer Technology KTH Royal Institute of Technology Stockholm Sweden
| | - Magnus Hakeberg
- Department of Behavioural and Community Dentistry Institute of Odontology/Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
| | - Ulf T. Örtengren
- Department of Clinical Dentistry Faculty of Health Sciences Tromsø University Tromsø Norway
- Department of Cariology Institute of Odontology/Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
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Elshazly TM, Bourauel C, Aboushelib MN, Sherief DI, El-Korashy DI. The polymerization efficiency of a bulk-fill composite based on matrix-modification technology. Restor Dent Endod 2020; 45:e32. [PMID: 32839713 PMCID: PMC7431929 DOI: 10.5395/rde.2020.45.e32] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 02/13/2020] [Accepted: 02/14/2020] [Indexed: 11/11/2022] Open
Abstract
Objectives To evaluate the polymerization efficiency of a matrix-modified bulk-fill composite, and compare it to a conventional composite which has a similar filler system. The degree of conversion (DC%) and monomer elution were measured over different storage periods. Additionally, fillers' content was examined. Materials and Methods Cylindrical specimens were prepared, in bulk and incrementally, from Filtek Bulk Fill (B) and Filtek Supreme XTE (S) composites using a Teflon mold, for each test (n = 6). Using attenuated total reflection method of Fourier transformation infrared spectroscopy, DC% was measured after 24 hours, 7 days, and 30 days. Using high-performance liquid chromatography, elution of hydroxyethyl methacrylate, triethylene glycol dimethacrylate, urethane dimethacrylate, and bisphenol-A glycidyl dimethacrylate was measured after 24 hours, 7 days and 30 days. Filler content was examined by scanning electron microscopy (SEM). Data were analyzed using 2-way mixed-model analysis of variance (α = 0.05). Results There was no significant difference in DC% over different storage periods between B-bulk and S-incremental. Higher monomer elution was detected significantly from S than B. The elution quantity and rate varied significantly over storage periods and between different monomers. SEM images showed differences in fillers' sizes and agglomeration between both materials. Conclusions Matrix-modified bulk-fill composites could be packed and cured in bulk with polymerization efficiency similar to conventional composites.
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Affiliation(s)
- Tarek M Elshazly
- Oral Technology, School of Dentistry, University of Bonn, Bonn, Germany.,Biomaterials Department, Faculty of Dentistry, Ain Shams University, Cairo, Egypt
| | | | | | - Dalia I Sherief
- Biomaterials Department, Faculty of Dentistry, Ain Shams University, Cairo, Egypt
| | - Dalia I El-Korashy
- Biomaterials Department, Faculty of Dentistry, Ain Shams University, Cairo, Egypt
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30
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Evaluation of Two Resin Composites Having Different Matrix Compositions. Dent J (Basel) 2020; 8:dj8030076. [PMID: 32709056 PMCID: PMC7559380 DOI: 10.3390/dj8030076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 07/14/2020] [Accepted: 07/15/2020] [Indexed: 11/16/2022] Open
Abstract
This study compared two resin composites with similar filler systems and different matrix compositions. The depth of cure (DoC), polymerization shrinkage, and marginal leakage were evaluated. A Filtek Bulk Fill resin composite (FB) and a Filtek Supreme resin composite (FS) were used. For the DoC and polymerization shrinkage, cylindrical specimens with different thicknesses were prepared. The DoC was attributed to the bottom/top ratios of Vickers microhardness numbers. For polymerization shrinkage, each specimen was firstly scanned using micro-computed tomography (µCT) then cured for 20 s, then for 10 s, and then for 10 s, and they were rescanned between each curing time. Data were processed using the Mimics software. For marginal leakage, standardized 5 mm cavities were prepared in 90 molars. After etching and bonding, materials were packed according to groups: FB-bulk, FB-incremental, and FS-incremental, which were cured for 20, 30, and 40 s, respectively. After thermo-cycling, teeth were stored in 1% methylene blue dye for 24 h and then sectioned and observed for dye penetration. The results showed insignificant differences in the shrinkage and leakage between the different packing techniques and curing times of both materials. In conclusion, the introduction of a novel matrix into resin composite composition enabled bulk-filling in one layer up to 5 mm deep while keeping a tolerable polymerization shrinkage.
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31
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Makhdoom SN, Campbell KM, Carvalho RM, Manso AP. Effects of curing modes on depth of cure and microtensile bond strength of bulk fill composites to dentin. J Appl Oral Sci 2020; 28:e20190753. [PMID: 32638829 PMCID: PMC7340207 DOI: 10.1590/1678-7757-2019-0753] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 05/19/2020] [Indexed: 11/22/2022] Open
Abstract
Objectives To compare the microtensile bond strength (µTBS) and depth of cure (DOC) of bulk-fill composites cured by monowave (MW) and polywave (PW) LED units using different curing times. Methodology Three composites were tested: Tetric EvoCeram Bulk Fill (TBF), Filtek Bulk Fill (FBF), and Tetric EvoCeram (T; control). Flat dentin surfaces treated with adhesive (AdheSE Universal®, Ivoclar Vivadent) were bonded with 4 mm cylindrical samples of each bulk-fill composite material (n=6) and cured with monowave (Satelec) or polywave (Bluephase Style) curing units for 10 or 20 seconds. After 24 hours, teeth were sectioned into individual 0.9 mm2 beams and tested for µTBS. Failure modes were analysed. Moreover, the DOC scrape test (IOS 4090) was completed (n=5) following the same curing protocols. Two-way ANOVA (a=0.05) was performed, isolating light-curing units. Results For samples cured with the MW light-curing unit, no significant effects were observed in the µTBS results between any of the resin composite brands and the curing times. Conversely, when resins were cured with a PW light unit, a significant effect was observed for TBF resin. In general, bulk-fill composites presented greater DOC and longer curing time resulted in higher DOC for all composites. Conclusion The µTBS of the composites to dentin was not affected by the curing mode of the resins, except for TBF cured with PW light unit. Bulk-fill composites exhibit greater DOC than conventional resin-based composites.
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Affiliation(s)
- Sara N Makhdoom
- Department of Oral Health Sciences, Faculty of Dentistry, The University of British Columbia, Vancouver, Canada
| | - Karen M Campbell
- Graduate Program in Pediatric Dentistry, Faculty of Dentistry, University of Toronto, Toronto, Canada
| | - Ricardo Marins Carvalho
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, The University of British Columbia, Vancouver, Canada
| | - Adriana Pigozzo Manso
- Department of Oral Health Sciences, Faculty of Dentistry, The University of British Columbia, Vancouver, Canada
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32
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Comba A, Scotti N, Maravić T, Mazzoni A, Carossa M, Breschi L, Cadenaro M. Vickers Hardness and Shrinkage Stress Evaluation of Low and High Viscosity Bulk-Fill Resin Composite. Polymers (Basel) 2020; 12:polym12071477. [PMID: 32630127 PMCID: PMC7407633 DOI: 10.3390/polym12071477] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 06/28/2020] [Accepted: 06/29/2020] [Indexed: 11/23/2022] Open
Abstract
The aim of this in vitro study was to evaluate the hardness and shrinkage stress (SS) of six bulk-fill resin composites. To evaluate microhardness (MH), ten 6 mm specimens were prepared using a metal mold for each selected bulk-fill resin composite and irradiated from the top side for 40 s using an LED light. After 24 h of storage, Vickers MH was evaluated on the upper, lower and lateral sides of the specimens. SS evaluation was then performed with a universal machine, which evaluated the contraction force generated by a bulk-fill composite specimen placed between two metal cylinders during and after light curing. The results were evaluated with a one-way ANOVA test with a post-hoc Bonferroni test and linear regression analysis (p < 0.05). All materials showed a significant MH decrease between the top and bottom surfaces. However, the bulk-fill materials tested performed differently when considering lateral depth progression. ANOVA tests for SS evaluation showed that both SDR and Venus Bulk Fill had significantly lower stress during irradiation than other tested materials. Further, MH decrease became significantly lower from the top surface at different depths in each tested group. Among the different resins, Venus Bulk Fill and SDR showed not only inferior hardness, but also a significant reduction in SS.
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Affiliation(s)
- Allegra Comba
- Department of Biomedical and Neuromotor Sciences, DIBINEM, University of Bologna, Alma Mater Studiorum, Via San Vitale 59, 40125 Bologna, Italy; (A.C.); (T.M.); (A.M.); (L.B.)
| | - Nicola Scotti
- Department of Surgical Science, CIR Dental School, University of Turin, Via Nizza 230, 10126 Turin, Italy;
- Correspondence: ; Tel.: +39-340-2861799
| | - Tatjana Maravić
- Department of Biomedical and Neuromotor Sciences, DIBINEM, University of Bologna, Alma Mater Studiorum, Via San Vitale 59, 40125 Bologna, Italy; (A.C.); (T.M.); (A.M.); (L.B.)
| | - Annalisa Mazzoni
- Department of Biomedical and Neuromotor Sciences, DIBINEM, University of Bologna, Alma Mater Studiorum, Via San Vitale 59, 40125 Bologna, Italy; (A.C.); (T.M.); (A.M.); (L.B.)
| | - Massimo Carossa
- Department of Surgical Science, CIR Dental School, University of Turin, Via Nizza 230, 10126 Turin, Italy;
| | - Lorenzo Breschi
- Department of Biomedical and Neuromotor Sciences, DIBINEM, University of Bologna, Alma Mater Studiorum, Via San Vitale 59, 40125 Bologna, Italy; (A.C.); (T.M.); (A.M.); (L.B.)
| | - Milena Cadenaro
- Department of Medical Sciences, University of Trieste, Strada di Fiume 447, 34149 Trieste, Italy;
- Institute for Maternal and Child Health—IRCCS “Burlo Garofolo”, Via dell’Istria 65/1, 34137 Trieste, Italy
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33
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de Cássia Romano B, Soto-Montero J, Rueggeberg FA, Giannini M. Effects of extending duration of exposure to curing light and different measurement methods on depth-of-cure analyses of conventional and bulk-fill composites. Eur J Oral Sci 2020; 128:336-344. [PMID: 32502304 DOI: 10.1111/eos.12703] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2020] [Indexed: 11/30/2022]
Abstract
This study evaluated the effect of extending the duration of exposure to curing light on the depth of cure of two conventional (RBC1-conventional and RBC2-conventional) and two bulk-fill (RBC1-bulk and RBC2-bulk) resin composites. Polywave and single-peak photocuring units were used. Cylinder-shaped specimens were exposed to curing light either for the time period recommended by the manufacturer or twice the length of that time, and depth of cure was estimated using manual scraping (similar to the ISO-4049 standard) and solvent immersion techniques. Depth of cure was analyzed, using two-way ANOVA, for the factors measurement method and exposure time. For RBC1-conventional and RBC1-bulk, the solvent immersion technique estimated a greater depth of cure than did manual scraping; for RBC1-conventional, both techniques and both light-exposure time periods resulted in a depth of cure of >2 mm; and for RBC1-bulk, only the solvent method after photocuring for twice the manufacturer's recommended time resulted in a depth of cure of 5 mm. For RBC2-conventional and RBC2-bulk, neither technique nor exposure time resulted in estimated depths of cure that matched those indicated by the manufacturer. The results suggest that extending the duration of photopolymerization increases depth of cure. Also, calculation of depth of cure can vary according to the measurement technique used.
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Affiliation(s)
- Beatriz de Cássia Romano
- Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | - Jorge Soto-Montero
- Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil.,Department of Restorative Dentistry, School of Dentistry, University of Costa Rica, Montes de Oca, Costa Rica
| | - Frederick A Rueggeberg
- Department of Restorative Sciences, Dental College of Georgia, Augusta University, Augusta, GA, USA
| | - Marcelo Giannini
- Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
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Aminoroaya A, Esmaeely Neisiany R, Nouri Khorasani S, Panahi P, Das O, Ramakrishna S. A Review of Dental Composites: Methods of Characterizations. ACS Biomater Sci Eng 2020; 6:3713-3744. [DOI: 10.1021/acsbiomaterials.0c00051] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alireza Aminoroaya
- Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Rasoul Esmaeely Neisiany
- Department of Materials and Polymer Engineering, Faculty of Engineering, Hakim Sabzevari University, Sabzevar 9617976487, Iran
| | - Saied Nouri Khorasani
- Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Parisa Panahi
- Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Oisik Das
- Material Science Division, Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå 97187, Sweden
| | - Seeram Ramakrishna
- Centre for Nanofibers and Nanotechnology, Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore
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Sirovica S, Solheim JH, Skoda MWA, Hirschmugl CJ, Mattson EC, Aboualizadeh E, Guo Y, Chen X, Kohler A, Romanyk DL, Rosendahl SM, Morsch S, Martin RA, Addison O. Origin of micro-scale heterogeneity in polymerisation of photo-activated resin composites. Nat Commun 2020; 11:1849. [PMID: 32296060 PMCID: PMC7160210 DOI: 10.1038/s41467-020-15669-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 03/20/2020] [Indexed: 11/18/2022] Open
Abstract
Photo-activated resin composites are widely used in industry and medicine. Despite extensive chemical characterisation, the micro-scale pattern of resin matrix reactive group conversion between filler particles is not fully understood. Using an advanced synchrotron-based wide-field IR imaging system and state-of-the-art Mie scattering corrections, we observe how the presence of monodispersed silica filler particles in a methacrylate based resin reduces local conversion and chemical bond strain in the polymer phase. Here we show that heterogeneity originates from a lower converted and reduced bond strain boundary layer encapsulating each particle, whilst at larger inter-particulate distances light attenuation and monomer mobility predominantly influence conversion. Increased conversion corresponds to greater bond strain, however, strain generation appears sensitive to differences in conversion rate and implies subtle distinctions in the final polymer structure. We expect these findings to inform current predictive models of mechanical behaviour in polymer-composite materials, particularly at the resin-filler interface. Resin-based-composites are widely used in industry and medicine but the influence of the filler particles on the reactive group conversion in photocurable resins is yet to be elucidated. Here the authors observe reduced local conversion and chemical bond strain in silica filler acrylate composite using synchrotron-based wide-field IR imaging.
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Affiliation(s)
- Slobodan Sirovica
- Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, Guy's Hospital, London, SE1 9RT, UK.,Aston Institute of Materials Research, School of Engineering & Applied Science, Aston University, Birmingham, B4 7ET, UK
| | - Johanne H Solheim
- Faculty of Science and Technology, Norwegian University of Life Sciences, Ås, 1432, Norway
| | - Maximilian W A Skoda
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, OX11 0QX, UK
| | - Carol J Hirschmugl
- Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI, 53211, USA
| | - Eric C Mattson
- Department of Materials Science and Engineering, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Ebrahim Aboualizadeh
- Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI, 53211, USA
| | - Yilan Guo
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, T6G 1C9, Canada
| | - Xiaohui Chen
- Division of Dentistry, School of Medical Sciences, The University of Manchester, Manchester, M13 9PL, UK
| | - Achim Kohler
- Faculty of Science and Technology, Norwegian University of Life Sciences, Ås, 1432, Norway
| | - Dan L Romanyk
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, T6G 1C9, Canada.,Department of Mechanical Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
| | - Scott M Rosendahl
- Canadian Light Source Inc., 44 Innovation Blvd., Saskatoon, SK, S7N 2V3, Canada
| | - Suzanne Morsch
- Corrosion and Protection Centre, School of Materials, The University of Manchester, Manchester, M13 9PL, UK
| | - Richard A Martin
- Aston Institute of Materials Research, School of Engineering & Applied Science, Aston University, Birmingham, B4 7ET, UK
| | - Owen Addison
- Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, Guy's Hospital, London, SE1 9RT, UK. .,Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, T6G 1C9, Canada.
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Sirovica S, Guo Y, Guan R, Skoda MWA, Palin WM, Morrell AP, Romanyk DL, Martin RA, Addison O. Photo-polymerisation variables influence the structure and subsequent thermal response of dental resin matrices. Dent Mater 2020; 36:343-352. [PMID: 31924386 DOI: 10.1016/j.dental.2019.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/20/2019] [Accepted: 12/11/2019] [Indexed: 10/25/2022]
Abstract
OBJECTIVE The structure of the polymer phase of dental resin-based-composites is highly sensitive to photo-polymerisation variables. The objective of this study was to understand how different polymer structures, generated with different photo-polymerisation protocols, respond to thermal perturbation. METHODS Experimental resins were prepared from a series of Bis-GMA/TEGDMA blends (40/60, 50/50 and 60/40 wt.%), with either Camphorquinone/DMAEMA or Lucirin TPO as the photo-initiator system. Resins were photo-polymerised, in a disc geometry, at either relatively 'high' (3000 mW cm-2 for 6 s) or 'low' (300 mW cm-2 for 60 s) irradiances ensuring matched radiant exposures (18 J cm-2). Specimens were heated, from 20-160 °C at a rate of 5 °C min-1, whilst simultaneous synchrotron X-ray scattering measurements were taken at 5 °C increments to determine changes in polymer chain segment extension and medium-range order as a function of temperature. For each unique resin composition (n = 3), differential scanning calorimetry was used to measure glass transition temperatures using the same heating protocol. A paired t-test was used to determine significant differences in the glass transition temperature between irradiance protocols and photo-initiator chemistry at ɑ = 0.05. RESULTS Resins pre-polymerised through the use of TPO and or high irradiances demonstrated a reduced rate of chain extension indicative of lower thermal expansion and a larger decrease in relative order when heated below the glass transition temperature. Above the transition temperature, differences in the rate of chain extension were negligible, but slower converted systems showed greater relative order. There was no significant difference in the glass transition temperature between different photo-initiator systems or irradiance protocols. SIGNIFICANCE The evolution of chain extension and medium-range order during heating is dependent on the initial polymer structure which is influenced by photo-polymerisation variables. Less ordered systems, generated at faster rates of reactive group conversion displayed reduced chain extension below the glass transition temperature and maintained lower order throughout heating.
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Affiliation(s)
- Slobodan Sirovica
- Aston Institute of Materials Research, School of Engineering & Applied Science, Aston University, Birmingham, B4 7ET, UK; Faculty of Dental, Oral and Craniofacial Science, King's College London, Guy's Hospital, London, SE1 9RT, UK.
| | - Yilan Guo
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, T6G 1C9, Canada
| | - Raymond Guan
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, T6G 1C9, Canada
| | - Maximilian W A Skoda
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, OX11 0QX, UK
| | - William M Palin
- College of Medical and Dental Sciences, Institute of Clinical Sciences, School of Dentistry, University of Birmingham, Mill Pool Way, Edgbaston, Birmingham, B5 7EG, UK
| | - Alexander P Morrell
- Aston Institute of Materials Research, School of Engineering & Applied Science, Aston University, Birmingham, B4 7ET, UK; Faculty of Dental, Oral and Craniofacial Science, King's College London, Guy's Hospital, London, SE1 9RT, UK
| | - Dan L Romanyk
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, T6G 1C9, Canada; Department of Mechanical Engineering, University of Alberta, Edmonton, T6G 1H9, Canada
| | - Richard A Martin
- Aston Institute of Materials Research, School of Engineering & Applied Science, Aston University, Birmingham, B4 7ET, UK
| | - Owen Addison
- Faculty of Dental, Oral and Craniofacial Science, King's College London, Guy's Hospital, London, SE1 9RT, UK; Faculty of Medicine and Dentistry, University of Alberta, Edmonton, T6G 1C9, Canada
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Aggarwal N, Jain A, Gupta H, Abrol A, Singh C, Rapgay T. The comparative evaluation of depth of cure of bulk-fill composites - An in vitro study. J Conserv Dent 2019; 22:371-375. [PMID: 31802822 PMCID: PMC6873606 DOI: 10.4103/jcd.jcd_453_18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Introduction Resin-based composites (RBCs), as restorative dental materials, have given a new dimension to conservative and esthetic dentistry. The objective of the present study is to evaluate and compare the depth of cure of RBC's for posterior use: Sculptable bulk-fill composite - Tetric N-Ceram bulk fill (TNCBF), Flowable bulk-fill composites-TetricEvoflow bulk fill (TEFBF), Surefil SDR bulk fill (SDRBF), Dual cure bulk fill-Fill-Up (FDCBF) with conventional RBC-Esthet-X flow (EXF) and Filtex Z250 (FZ). Materials and Methods A standardized polyacrylic mold was bulk filled with each of the six composites and light-cured for 20 s, followed by 24 h storage in water. The surface hardness was measured on the top and the bottom by recording Vickers hardness number by Vickers hardness indenter. Results The mean bottom surface hardness value (HV) of SDR and TEFBF exceeded 80% of the top surface HV (HV-80%). Low viscosity bulk-fill composites (SDR and Tetric Evoflow) were properly cured in 4-mm increments. The TNCBF, high-viscosity composite, and Fill-Up, dual-cure bulk fill were not sufficiently cured in 4-mm increments. Conclusion With increase in incremental thickness, HV decreased for the conventional resin composite but generally remained constant for the bulk-fill resin composites.
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Affiliation(s)
- Nidhi Aggarwal
- Department of Conservative Dentistry and Endodontics, Himachal Institute of Dental Sciences, Paonta Sahib, HP, India
| | - Anjula Jain
- Department of Conservative Dentistry and Endodontics, Himachal Institute of Dental Sciences, Paonta Sahib, HP, India
| | - Hitesh Gupta
- Department of Conservative Dentistry and Endodontics, Himachal Institute of Dental Sciences, Paonta Sahib, HP, India
| | - Aman Abrol
- Department of Conservative Dentistry and Endodontics, Himachal Institute of Dental Sciences, Paonta Sahib, HP, India
| | - Charanjeet Singh
- Department of Conservative Dentistry and Endodontics, Himachal Institute of Dental Sciences, Paonta Sahib, HP, India
| | - Tenzin Rapgay
- Department of Conservative Dentistry and Endodontics, Himachal Institute of Dental Sciences, Paonta Sahib, HP, India
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Sirovica S, Skoda MWA, Podgorski M, Thompson PBJ, Palin WM, Guo Y, Smith AJ, Dewan K, Addison O, Martin RA. Structural Evidence That the Polymerization Rate Dictates Order and Intrinsic Strain Generation in Photocured Methacrylate Biomedical Polymers. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b00133] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Slobodan Sirovica
- Aston Institute of Materials Research, School of Engineering & Applied Science, University of Aston, Birmingham B4 7ET, U.K
| | - Maximilian W. A. Skoda
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot OX11 0QX, U.K
| | - Maciej Podgorski
- Department of Chemical and Biological Engineering, University of Colorado Boulder, 596 UCB Boulder, Colorado 80309, United States
- Faculty of Chemistry, Department of Polymer Chemistry, Maria Curie-Sklodowska University, Gliniana Street 33, 20-614 Lublin, Poland
| | | | - William M. Palin
- College of Medical and Dental Sciences, Institute of Clinical Sciences, School of Dentistry, University of Birmingham, Mill Pool Way,
Edgbaston, Birmingham B5 7EG, U.K
| | - Yilan Guo
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton T6G 1C9, Canada
| | - Andrew J. Smith
- Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, U.K
| | - Karun Dewan
- College of Medical and Dental Sciences, Institute of Clinical Sciences, School of Dentistry, University of Birmingham, Mill Pool Way,
Edgbaston, Birmingham B5 7EG, U.K
| | - Owen Addison
- College of Medical and Dental Sciences, Institute of Clinical Sciences, School of Dentistry, University of Birmingham, Mill Pool Way,
Edgbaston, Birmingham B5 7EG, U.K
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton T6G 1C9, Canada
| | - Richard A. Martin
- Aston Institute of Materials Research, School of Engineering & Applied Science, University of Aston, Birmingham B4 7ET, U.K
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Favarão J, Oliveira DCRSD, Rocha MG, Zanini MM, Abuna GF, Mendonça MJ, Sinhoreti MAC. Solvent Degradation and Polymerization Shrinkage Reduction of Resin Composites Using Isobornyl Methacrylate. Braz Dent J 2019; 30:272-278. [DOI: 10.1590/0103-6440201802525] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 01/17/2019] [Indexed: 11/21/2022] Open
Abstract
Abstract The aim of this study was to use the isobornyl methacrylate (IBOMA) as a combining or substituent diluent monomer in the resin matrix of dental resin composites. Thus, the resin matrix was formulated with 60 wt% of BisGMA and 40 wt% of diluent monomers. TEGDMA as the only diluent monomer was used as control with 40 wt%, while total substitution of TEGDMA was done with 40 wt% of IBOMA. The combination of IBOMA and TEGDMA was done with 20 wt% of each monomer. To the resin matrix, 65 wt% of filler particles was added. Degree of conversion (DC) using FT-IR, flexural strength (FS), flexural modulus (FM), polymerization shrinkage by gap formation (GF), Knoop hardness (KH) and solvent degradation (SD) were evaluated. Data were analyzed using ANOVA and Tukey’s test (α=0.05; b=0.2). The results showed that reducing or substituting TEGDMA using IBOMA did not affect the DC (0.085), FS (p=0.886) or FM (p=0.414). Also, when IBOMA was used, lower GF was found in comparison to the control containing only TEGDMA as the diluent monomer (p=0.032). However, even though all composites presented reduction in KH during the SD test, the combination of IBOMA and TEGDMA showed similar reduction in KHN in comparison to the control group (p=0.001), while the total substitution of TEGDMA with IBOMA decreased KHN after SD (p=0.041). Thus, the combination of IBOMA and TEGDMA seem to reduce SD and GF without affecting the properties of resin composites.
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Al-Zain AO, Eckert GJ, Platt JA. The Influence of Distance on Radiant Exposure and Degree of Conversion Using Different Light-Emitting-Diode Curing Units. Oper Dent 2019; 44:E133-E144. [DOI: 10.2341/18-004-l] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
Objectives:
To investigate the influence of curing distance on the degree of conversion (DC) of a resin-based composite (RBC) when similar radiant exposure was achieved using six different light-curing units (LCUs) and to explore the correlation among irradiance, radiant exposure, and DC.
Methods and Materials:
A managing accurate resin curing-resin calibrator system was used to collect irradiance data for both top and bottom specimen surfaces with a curing distance of 2 mm and 8 mm while targeting a consistent top surface radiant exposure. Square nanohybrid-dual-photoinitiator RBC specimens (5 × 5 × 2 mm) were cured at each distance (n=6/LCU/distance). Irradiance and DC (micro-Raman spectroscopy) were determined for the top and bottom surfaces. The effect of distance and LCU on irradiance, radiant exposure, and DC as well as their linear associations were analyzed using analysis of variance and Pearson correlation coefficients, respectively (α=0.05).
Results:
While maintaining a similar radiant exposure, each LCU exhibited distinctive patterns in decreased irradiance and increased curing time. No significant differences in DC values (63.21%-70.28%) were observed between the 2- and 8-mm distances, except for a multiple-emission peak LCU. Significant differences in DC were detected among the LCUs. As expected, irradiance and radiant exposure were significantly lower on the bottom surfaces. However, a strong correlation between irradiance and radiant exposure did not necessarily result in a strong correlation with DC.
Conclusions:
The RBC exhibited DC values >63% when the top surface radiant exposure was maintained, although the same values were not reached for all lights. A moderate-strong correlation existed among irradiance, radiant exposure, and DC.
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Affiliation(s)
- AO Al-Zain
- Afnan O Al-Zain, BDS, MSD, PhD, King Abdulaziz University, Faculty of Dentistry, Restorative Dentistry Department, Jeddah, Saudi Arabia
| | - GJ Eckert
- George J Eckert, MS, Indiana University School of Medicine, Division of Biostatistics, Indianapolis, IN, USA
| | - JA Platt
- Jeffrey A Platt, DDS, MS, Indiana University, Department of Biomedical and Applied Sciences, Indianapolis, IN, USA
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Fahim SE, Mostafa MA, Abi-Elhassan MH, Taher HM. Clinical Behaviour and Marginal Sealing of Bulk-Fill Resin Composite Restorations Using Light Amplified High-Intensity LEDs Curing: A Randomized Controlled Clinical Trial. Open Access Maced J Med Sci 2019; 7:1360-1368. [PMID: 31110586 PMCID: PMC6514356 DOI: 10.3889/oamjms.2019.216] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 04/14/2019] [Accepted: 04/15/2019] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND: Delivering sufficient intensity output of curing lights is mandatory to ensure optimum cure and clinical success of bulk-fill resin composite restorations and to avoid undesirable clinical outcomes. AIM: To evaluate the effectiveness of using light amplified high intensity LED curing on the clinical performance and marginal sealing of posterior bulk-fill resin composite restorations. MATERIAL AND METHODS: This study was designed as a randomised, controlled, double-blind, Unicenter, parallel, two arms, superiority trial with 1:1 allocation ratio. Adult patients who required posterior tooth-coloured restorations were asked to participate in this trial. All participants signed written informed consent after being completely aware of the settings of the study. The participants who fulfilled the eligibility criteria were divided into two groups according to the type of light curing mode used. Adhesive compound proximal cavities were prepared. All restorative materials were applied according to the respective manufacturer’s instructions. Assessments of the restorations were done at baseline (one week after placement of the restoration), after 6 months and after 12 months using the modified US Public Health Service (USPHS) criteria. For quantitative assessment of the marginal sealing, resin replicas were analysed using scanning electron microscopy. Statistical analysis was done using Chi-square, Mann Whitney, independent t-test and dependent t-tests. RESULTS: There were no statistical differences between the two groups for the tested clinical parameters along the study periods. For marginal analysis, there were no statistical differences between the intervention and control group at baseline and six months (p-value = 0.347 and 0.516) respectively. At 12 months the control group showed statistically significant higher percentages (p-value = 0.031). CONCLUSION: Light amplified high-intensity curing units have clinical performance comparable with the conventional LED.
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Al-Zain AO, Eckert GJ, Lukic H, Megremis S, Platt JA. Polymerization pattern characterization within a resin-based composite cured using different curing units at two distances. Clin Oral Investig 2019; 23:3995-4010. [PMID: 30737620 DOI: 10.1007/s00784-019-02831-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 01/25/2019] [Indexed: 12/14/2022]
Abstract
OBJECTIVES To investigate the relationship of the irradiance-beam-profile areas from six different light-curing units (LCUs) with the degree of conversion (DC), microhardness (KH), and cross-link density (CLD) throughout a resin-based composite (RBC) cured at two clinically relevant distances, and to explore the correlations among them. MATERIALS AND METHODS A mapping approach was used to measure DC using micro-Raman spectroscopy, KH using a Knoop indentor on a hardness tester, and %KH reduction after ethanol exposure, as an indicator for CLD within a nano-hybrid RBC increment (n = 3) at various depths. These sample composites were cured from two distances while maintaining the radiant exposure, using six different light-curing units: one quartz-tungsten-halogen; two single and three multiple-emission-peak light-emitting-diode units. Irradiance beam profiles were generated for each LCU at both distances, and localized irradiance values were calculated. Points across each depth were analyzed using repeated measures ANOVA. Correlations across multiple specimen locations and associations between beam uniformity corresponding with polymerization measurements were calculated using linear mixed models and Pearson correlation coefficients. RESULTS Significant non-uniform polymerization patterns occurred within the specimens at various locations and depths. At 2-mm curing distance, the localized DC = 52.7-76.8%, KH = 39.0-66.7 kg/mm2, and %KH reduction = 26.7-57.9%. At 8-mm curing distance, the localized DC = 50.4-78.6%, KH = 40.3-73.7 kg/mm2, and %KH reduction = 28.2-56.8%. The localized irradiance values were weakly correlated with the corresponding DC, KH, and %KH reduction, with only a few significant correlations (p < 0.05). CONCLUSIONS Although significant differences were observed at each depth within the specimens, the localized irradiance values for all LCUs did not reflect the polymerization pattern and did not seem to have a major influence on polymerization patterns within the RBC, regardless of the curing distance. CLINICAL RELEVANCE Commonly used LCUs do not produce uniform polymerization regardless of the curing distance, which may contribute to the risk of RBC fracture.
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Affiliation(s)
- Afnan O Al-Zain
- Restorative Dentistry Department, Faculty of Dentistry, King Abdulaziz University, P.O. Box: 80209, Jeddah, 21589, Saudi Arabia.
| | - George J Eckert
- Department of Biostatistics, Indiana University School of Medicine, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA
| | - Henry Lukic
- Research and Standards, American Dental Association Science Institute, Chicago, IL, USA
| | - Spiro Megremis
- Research and Standards, American Dental Association Science Institute, Chicago, IL, USA
| | - Jeffrey A Platt
- Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA
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Lima MO, Catelan A, Marchi GM, Lima DA, Martins LR, Aguiar FH. Influence of pre-heating and ceramic thickness on physical properties of luting agents. J Appl Biomater Funct Mater 2018; 16:252-259. [PMID: 29983080 DOI: 10.1177/2280800018782842] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
PURPOSE The objective of this in vitro study was to evaluate the influence of ceramic thickness and pre-heating of luting agents on their physical properties. MATERIALS AND METHODS The materials RelyX Arc, RelyX Ultimate, RelyX Veneer, and Filtek Z350 Flow were handled at different temperatures (23°C or 54°C), inserted into matrix, and photoactivated through ceramic disks (0.75 mm or 1.5 mm). The following tests were performed ( n=8): degree of conversion, Knoop Hardness, cross-link density, water sorption, solubility, and ultimate tensile strength. Data were analyzed using three-way analysis of variance and Tukey's test (α=0.05). RESULTS Regarding ceramic thickness, the thinnest ceramic resulted in higher values of Knoop Hardness ( p=0.027). The lowest temperature (23°C) resulted in a higher solubility ( p=0.0257), and water sorption ( p=0.0229) values. There was also statistical difference among the materials: RelyX Arc showed a higher degree of conversion and ultimate tensile strength, followed by RelyX Veneer, RelyX Ultimate, and Filtek Z350 Flow. For Knoop Hardness and cross-link density tests, RelyX Ultimate showed the highest values, followed by RelyX Arc, RelyX Veneer, and Filtek Z350 Flow. For water sorption and solubility, RelyX Veneer showed the highest values, followed by RelyX Arc, RelyX Ultimate, and Filtek Z350 Flow. CONCLUSION Pre-heating interfered with water sorption and solubility, whereas ceramic thickness only affected Knoop Hardness; the physical properties of the materials are dependent on their composition.
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Affiliation(s)
- Michele O Lima
- 1 Department of Restorative Dentistry, State University of Campinas, Piracicaba, Brazil
| | - Anderson Catelan
- 2 Department of Dentistry, University of Western São Paulo, Presidente Prudente, Brazil
| | - Giselle M Marchi
- 1 Department of Restorative Dentistry, State University of Campinas, Piracicaba, Brazil
| | - Débora Anl Lima
- 1 Department of Restorative Dentistry, State University of Campinas, Piracicaba, Brazil
| | - Luís Rm Martins
- 1 Department of Restorative Dentistry, State University of Campinas, Piracicaba, Brazil
| | - Flávio Hb Aguiar
- 1 Department of Restorative Dentistry, State University of Campinas, Piracicaba, Brazil
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Hardy CMF, Bebelman S, Leloup G, Hadis MA, Palin WM, Leprince JG. Investigating the limits of resin-based luting composite photopolymerization through various thicknesses of indirect restorative materials. Dent Mater 2018; 34:1278-1288. [PMID: 29857990 DOI: 10.1016/j.dental.2018.05.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 04/16/2018] [Accepted: 05/09/2018] [Indexed: 01/19/2023]
Abstract
OBJECTIVE To determine the limitations of using light-curable resin-based luting composites (RBLCs) to bond indirect ceramic/resin-composite restorations by measuring light transmittance through indirect restorative materials and the resulting degree of conversion (DC) of the luting-composites placed underneath. METHODS Various thicknesses (0-4mm) and shades of LAVA Zirconia and LAVA Ultimate were prepared and used as light curing filters. A commercial, light curable RBLC, RelyX Veneer (control) was compared with four experimental RBLCs of the following composition: TEGDMA/BisGMA (50/50 or 30/70wt%, respectively); camphorquinone/amine (0.2/0.8wt%) or Lucirin-TPO (0.42wt%); microfillers (55wt%) and nanofillers (10wt%). RBLCs covered with the LAVA filter were light-cured for 40s, either with the dual-peak BluephaseG2 or an experimental device emitting either in the blue or violet visible band. The samples were analyzed by Raman spectroscopy to determine DC. Light transmittance through the filters was measured using a common spectroscopy technique. RESULTS All the factors studied significantly influenced DC (p<0.05). RBLCs with increased TEGDMA content exhibited higher DC. Only small differences were observed comparing DC without filters and filters ≤1mm (p>0.05). For thicknesses ≥2mm, significant reductions in DC were observed (p<0.05). Transmittance values revealed higher filter absorption at 400nm than 470nm. A minimal threshold of irradiance measured through the filters that maintained optimal DC following 40s irradiation was identified for each RBLC formulation, and ranged between 250-500mW/cm2. SIGNIFICANCE This work confirmed that optimal photopolymerization of RBLCs through indirect restorative materials (≤4mm) and irradiation time of 40s is possible, but only in some specific conditions. The determination of such conditions is likely to be key to clinical success, and all the factors need to be optimized accordingly.
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Affiliation(s)
- C M F Hardy
- School of Dental Medicine and Stomatology, at Cliniques Universitaires Saint-Luc, Universite catholique de Louvain, Belgium; Advanced Drug Delivery and Biomaterials (ADDB), Louvain Drug Research Institute (LDRI), Université catholique de Louvain, Brussels, Belgium; Bio- and Soft- Matter (BSMA), Institute of Condensed Matter and Nanoscience (IMCN), Université catholique de Louvain, Louvain-la-Neuve, Belgium.
| | - S Bebelman
- Bio- and Soft- Matter (BSMA), Institute of Condensed Matter and Nanoscience (IMCN), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - G Leloup
- School of Dental Medicine and Stomatology, at Cliniques Universitaires Saint-Luc, Universite catholique de Louvain, Belgium; Advanced Drug Delivery and Biomaterials (ADDB), Louvain Drug Research Institute (LDRI), Université catholique de Louvain, Brussels, Belgium; Bio- and Soft- Matter (BSMA), Institute of Condensed Matter and Nanoscience (IMCN), Université catholique de Louvain, Louvain-la-Neuve, Belgium; CRIBIO (Center for Research and Engineering on Biomaterials), Brussels, Belgium
| | - M A Hadis
- Biomaterials Unit, University of Birmingham, College of Medical and Dental Sciences, Institute of Clinical Sciences, School of Dentistry, 5 Mill Pool Way, Birmingham B5 7EG, UK
| | - W M Palin
- Biomaterials Unit, University of Birmingham, College of Medical and Dental Sciences, Institute of Clinical Sciences, School of Dentistry, 5 Mill Pool Way, Birmingham B5 7EG, UK
| | - J G Leprince
- School of Dental Medicine and Stomatology, at Cliniques Universitaires Saint-Luc, Universite catholique de Louvain, Belgium; Advanced Drug Delivery and Biomaterials (ADDB), Louvain Drug Research Institute (LDRI), Université catholique de Louvain, Brussels, Belgium; Bio- and Soft- Matter (BSMA), Institute of Condensed Matter and Nanoscience (IMCN), Université catholique de Louvain, Louvain-la-Neuve, Belgium; CRIBIO (Center for Research and Engineering on Biomaterials), Brussels, Belgium
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Shining a light on high volume photocurable materials. Dent Mater 2018; 34:695-710. [DOI: 10.1016/j.dental.2018.02.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 02/22/2018] [Accepted: 02/28/2018] [Indexed: 12/29/2022]
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Xue J, Kannan P, Kumosani TA, Al-Malki AL, Kannan K. Resin-based dental sealants as a source of human exposure to bisphenol analogues, bisphenol A diglycidyl ether, and its derivatives. ENVIRONMENTAL RESEARCH 2018; 162:35-40. [PMID: 29276977 DOI: 10.1016/j.envres.2017.12.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 12/12/2017] [Accepted: 12/13/2017] [Indexed: 06/07/2023]
Abstract
Although studies have examined leaching of bisphenol A (BPA) from dental sealants into saliva, occurrence of BPA, bisphenol A diglycidyl ether (BADGE), and their derivatives in dental sealants themselves has not been investigated. In this study, concentrations of eight bisphenol analogues (BPs), BADGE and its derivatives (BADGEs), including BADGE‧H2O, BADGE‧HCl, BADGE‧2H2O, BADGE‧2HCl, and BADGE‧H2O‧HCl, were determined in 70 dental sealants collected from the U.S. market. Of the 70 dental sealants analyzed, 65 contained at least one of the target chemicals measured. BADGE‧2H2O was the most abundant compound, found at concentrations of up to 1780µg/g. The geometric mean (GM) concentration of total BADGEs was 47.8µg/g, which was two to three orders of magnitude higher than that of total BPs (GM: 539ng/g). BPA was found in 46% of the sealants and BADGEs was found in 87% of the sealants analyzed. Majority of the dental sealants analyzed in this study were manufactured in the United States and Korea; no significant differences were observed in the concentrations of BPs and BADGEs between the two countries. An exposure assessment was made based on the concentrations of BPs and BADGEs measured in sealants and their application rates in dentistry. The worst-case exposure scenario with the highest measured concentration of total BPs and BADGEs and application on 8 teeth at 8mg each yielded an estimated daily intake (EDI) of 1670 and 5850ng/kg·bw/day for adults and children, respectively. Although the EDI is below the specific migration limit set by the European Food Safety Authority, dental sealants are a source of exposure to BPs and BADGEs, especially in children.
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Affiliation(s)
- Jingchuan Xue
- Wadsworth Center, New York State Department of Health, and Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Empire State Plaza, P.O. Box 509, Albany, NY 12201-0509, USA
| | - Pranav Kannan
- Wadsworth Center, New York State Department of Health, and Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Empire State Plaza, P.O. Box 509, Albany, NY 12201-0509, USA
| | - Taha A Kumosani
- Biochemistry Department, Faculty of Science, and Production of Bioproducts for Industrial Applications Research Group and Experimental Biochemistry Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Abdulrahman L Al-Malki
- Biochemistry Department, Faculty of Science, Bioactive Natural Products Research Group, and Experimental Biochemistry Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Kurunthachalam Kannan
- Wadsworth Center, New York State Department of Health, and Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Empire State Plaza, P.O. Box 509, Albany, NY 12201-0509, USA; Biochemistry Department, Faculty of Science, and Production of Bioproducts for Industrial Applications Research Group and Experimental Biochemistry Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia.
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Guidelines for the selection, use, and maintenance of LED light-curing units - Part 1. Br Dent J 2018; 221:453-460. [PMID: 27767163 DOI: 10.1038/sj.bdj.2016.772] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2016] [Indexed: 11/08/2022]
Abstract
Light curing is a critical step in the restorative process when using light-activated resin-based composites, but it is frequently not given the attention it deserves. The selection of a reliable light curing unit (LCU) that meets the practitioner's needs is an important equipment purchase. Using an inappropriate LCU may seriously compromise the quality of care without the practitioner realising their mistake until years later. The importance of the subject is reflected by the rapidly increasing use of light-cured composites and the decline in the use of amalgam. Many changes have occurred in the equipment and materials available for making light-cured restorations in the last twenty years. This article is part of a two-part series that will describe those changes and recommend guidelines for the selection, use, and maintenance of light emitting diode light-curing units (LED LCUs). This paper (Part 1) discusses terminology, clinical studies, the development of LCUs in dentistry, the aims of light-curing, and the need to deliver an adequate amount of energy. The interaction between light source and material is briefly described to demonstrate the complex nature of the resin photopolymerisation process.
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Alrahlah A. Diametral Tensile Strength, Flexural Strength, and Surface Microhardness of Bioactive Bulk Fill Restorative. J Contemp Dent Pract 2018; 19:13-19. [PMID: 29358529 DOI: 10.5005/jp-journals-10024-2205] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
AIM The aim was to perform comparative analysis of bioactive, contemporary bulk-fill resin-based composites (RBCs) and conventional glass-ionomer materials for flexural strength (FS), diametral tensile strength (DTS), and Vickers hardness number (VHN) in the presence of thermocycling. MATERIALS AND METHODS Five restorative materials [Tetric N-Ceram Bulk Fill; smart dentin replacement (SDR) Flowable Material; Bioactive restorative material (ACTIVA Bulk Fill); Ketac Universal Aplicap; and GC Fuji II] were evaluated for DTS, FS, and VHN. Half the samples in each material group were ther-mocycled. The DTS was performed under compressive load at a cross-head speed of 1.0 mm/min. The FS was assessed by three-point bending test at a cross-head speed of 0.5 mm/min. The VHN was determined using a Vickers diamond indenter at 50 gf load for 15 seconds. Differences in FS, DTS, and VHN were analyzed using analysis of variance (ANOVA) and Tukey post hoc tests at a = 0.05 level of significance. RESULTS N-Ceram, ACTIVA, and SDR demonstrated the highest and comparable (p > 0.05) FS. The SDR had the highest DTS value (141.28 ± 0.94), followed by N-Ceram (136.61 ± 1.56) and ACTIVA (129.05 ± 1.78). Ketac had the highest VHN value before and after thermocycling. CONCLUSION ACTIVA showed mechanical properties (FS and DTS) comparable with bulk-fill resin composite materials. ACTIVA showed potential for durability, as VHN was comparable post-thermocycling. CLINICAL SIGNIFICANCE Bioactive materials showed acceptable DTS and FS values. However, hardness was compromised compared with included materials. ACTIVA Bulk Fill shows potential for dentin replacement but it needs to be covered with a surface-resistant restorative material. Further studies to improve surface characteristics of ACTIVA Bulk Fill are recommended.
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Affiliation(s)
- Ali Alrahlah
- Department of Restorative Dental Science, King Saud University Riyadh, Kingdom of Saudi Arabia, Phone: +00966114678304, e-mail:
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Ferracane J, Hilton T, Stansbury J, Watts D, Silikas N, Ilie N, Heintze S, Cadenaro M, Hickel R. Academy of Dental Materials guidance—Resin composites: Part II—Technique sensitivity (handling, polymerization, dimensional changes). Dent Mater 2017; 33:1171-1191. [DOI: 10.1016/j.dental.2017.08.188] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 08/29/2017] [Indexed: 11/30/2022]
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Marcinkowska A, Gauza-Wlodarczyk M, Kubisz L, Hedzelek W. The electrical properties and glass transition of some dental materials after temperature exposure. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2017; 28:186. [PMID: 29039617 DOI: 10.1007/s10856-017-5996-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 10/05/2017] [Indexed: 06/07/2023]
Abstract
The physicochemical properties of dental materials will remain stable only when these materials in question are resistant to the changes in the oral cavity. The oral environment is subject to large temperature variations. The aim of the study was the assessment of electrical properties and glass transition of some dental materials after temperature exposure. Composite materials, compomers, materials for temporary prosthetic replacement and resin-based pit and fissure sealants were used in the study. The method used was electric conductivity of materials under changing temperature. The order of materials presenting the best characteristics for insulators was as follows: materials for temporary prosthetic replacement, resin-based pit and fissure sealants, composites, and compomers. Thanks to comparisons made between graphs during I and II heating run, the method could be used to observe changes in the heated material and determine whether the changes observed are reversible or permanent. The graphs also provided temperature values which contain information on glass transition during heating. In the oral cavity the effect of the constant temperature stimulus influences maturity of dental materials and improves their properties. But high temperatures over glass transition temperature can cause irreversible deformation and changes of the materials properties, even in a short time.
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Affiliation(s)
- Agnieszka Marcinkowska
- Department of Prosthetic Dentistry, University of Medical Sciences, 70 Bukowska Street, 60-812, Poznan, Poland.
| | - Marlena Gauza-Wlodarczyk
- Department of Biophysics, University of Medical Sciences, Collegium Chemicum, 6 Grunwaldzka Street, 60-780, Poznan, Poland
| | - Leszek Kubisz
- Department of Biophysics, University of Medical Sciences, Collegium Chemicum, 6 Grunwaldzka Street, 60-780, Poznan, Poland
| | - Wieslaw Hedzelek
- Department of Prosthetic Dentistry, University of Medical Sciences, 70 Bukowska Street, 60-812, Poznan, Poland
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