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Peres TS, de Quirino Oliveira HL, Mendoza LCL, Ribeiro MTH, Carlo HL, Price RB, Soares CJ. Effect of four different mono and multi-wave light-curing units on the Knoop hardness of veneer resin composites. Dent Mater 2024; 40:80-89. [PMID: 37919111 DOI: 10.1016/j.dental.2023.10.019] [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: 04/28/2023] [Accepted: 10/20/2023] [Indexed: 11/04/2023]
Abstract
OBJECTIVES To evaluate the effect of mono and multi-wave light-curing units (LCUs) on the Knoop hardness of resin-based composites (RBC) that use different photoinitiators. METHODS Central incisor-shaped specimens 12 mm long, 9 mm wide, and 1.5 mm thick were made from 2 RBCs that use different photoinitiators: Tetric N-Ceram (Ivoclar Vivadent) - and Vittra APS (FGM), both A2E shade. They were light-cured with 4 different LCUs: two claimed to be multi-wave - VALO Grand (Ultradent) and Emitter Now Duo (Schuster); and two were monowave - Radii Xpert (SDI) and Elipar DeepCure-L (3 M Oral Care) using 2 different light exposure protocols: one 40 s exposure centered over the specimen; and two 20 s light exposures that delivered light from two positions to better cover the entire tooth. 16 groups with 10 specimens in each group were made. The Knoop hardness (KH, kg/mm2) was measured at the top and bottom of the specimen in the center and at the cervical, incisal, mesial, and distal peripheral regions. The active tip diameters (mm) and spectral radiant powers (mW/nm) of the LCUs were measured with and without the interposition of the RBC, as well as the radiant exposure beam profiles (J/cm²) delivered to the top of the RBCs. The data was analyzed using Three-way ANOVA and Tukey's tests (α = 0.05). RESULTS The VALO Grand (1029 mW) emitted twice the power of the Radii Xpert (500 mW). The KH values of VI and TN resin composite specimens were significantly affected by the LCU used (p < .001), the measurement location (p < .001), and the surface of the specimen (p < .001). LCUs with wider tip diameters produced greater Knoop hardness values at the peripheries of the 12 mm of long, 9 mm wide specimens. In general, the VALO Grand produced the highest KH values, followed by Elipar DeepCure-L, then by Radii Xpert. The Emitter Now Duo LCU produced the lowest values. Exposing the veneers from two locations reduced the differences between the LCUs and the effect of the measurement location. Only the VALO Grand could fully cover the composite veneer with light when the two locations were used. SIGNIFICANCE The light tip must cover the entire restoration to photocure the RBC beneath the light tip.
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Affiliation(s)
- Thiago Silva Peres
- School of Dentistry, UFU - Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | | | | | | | - Hugo Lemes Carlo
- Dentistry Department, School of Dentistry, UFU - Universidade Federal de Uberlândia, MG, Brazil
| | - Richard Bengt Price
- Dental Clinical Sciences Department and School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Carlos José Soares
- Dentistry Department, School of Dentistry, UFU - Universidade Federal de Uberlândia, MG, Brazil.
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Aravind P, Mohan Kallat A, Kumar Sivabalan P, Mathew Velurethu S, Vijayan N, Augustine C. An In Vitro Comparison of Shear Bond Strength for Heated Composite Resin With Three Conventional Luting Cements. Cureus 2023; 15:e47110. [PMID: 38022161 PMCID: PMC10646979 DOI: 10.7759/cureus.47110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 10/14/2023] [Indexed: 12/01/2023] Open
Abstract
Background: This research set out to collate and contrast three popular luting agents-heated composite resin, resin-modified glass ionomer cement (RMGIC), and resin cement, and light-cure resin cement by measuring their shear bond strengths. Shear bond strength was measured between lithium disilicate discs (IPS E-max) and specimens luted with heated composite resin (Tetric N-Ceram, Ivoclar Vivadent), self-adhesive resin cement (3M ESPE Rely X U200), light-activated resin cement (Rely X Veneer cement), and resin-modified glass ionomer cement (Fuji Plus, GC America). A comparison was made between the shear bond strength of standard luting cement and heated composite resin on lithium disilicate discs. MATERIALS AND METHODS Forty-eight lithium disilicate disc samples are collected and put on acrylic blocks for this investigation. To improve luting cement adhesion, the discs are etched with 5% hydrofluoric acid (HF) gel. For easier handling and lower viscosity during luting, the composite resin is heated to between 55 and 68°C on a digital wax melter. Shear bond strength tests were executed with the universal testing device after the following luting cement was applied in the center of the test specimen (lithium disilicate discs). Statistics software was used for the calculations and analysis. RESULTS In accordance with the findings of the tests, shear bond strengths ranged from 2.2851 ± 0.5901 for nanohybrid composite resin to 7.3740 ± 0.6969 for self-adhesive resin cement and 4.4647 ± 0.9774 for light-activated resin cement. A statistically significant (p≤0.001) difference between the groups was found. Mean shear bond strength was significantly highest in the self-adhesive resin cement group, followed by the light-activated resin cement group, resin-modified GIC, and least with the nanohybrid composite resin group. CONCLUSION Composite resins; in fixation of indirect restorations can have their viscosity reduced by preheating in a device, but they must be employed as soon as possible after removal. Standardizing the methods of heating composite resins for cementation is necessary to achieve desirable outcomes and direct the physician in their application. Although preheating composite resins for luting operations can be utilized to decrease the material's viscosity and enhance the restoration setting; it may not increase bond strength.
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Affiliation(s)
- Prasad Aravind
- Department of Prosthodontics, Crown and Bridge, Mahe Institute of Dental Sciences and Hospital, Puducherry, IND
| | - Abhinav Mohan Kallat
- Department of Prosthodontics, Crown and Bridge, Mahe Institute of Dental Sciences and Hospital, Puducherry, IND
| | - Prem Kumar Sivabalan
- Department of Prosthodontics, Crown and Bridge, Mahe Institute of Dental Sciences and Hospital, Puducherry, IND
| | - Shibi Mathew Velurethu
- Department of Prosthodontics, Crown and Bridge, Pushpagiri College of Dental Sciences, Thiruvalla, IND
| | - Nirosha Vijayan
- Department of Prosthodontics, Crown and Bridge, Mahe Institute of Dental Sciences and Hospital, Puducherry, IND
| | - Cimmy Augustine
- Department of Prosthodontics, Crown and Bridge, Mahe Institute of Dental Sciences and Hospital, Puducherry, IND
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Liao W, Liao Q, Xiong Y, Li Z, Tang H. Design, synthesis and properties of carbazole-indenedione based photobleachable photoinitiators for photopolymerization. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.114297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Bellotti V, Simonutti R. New Light in Polymer Science: Photoinduced Reversible Addition-Fragmentation Chain Transfer Polymerization (PET-RAFT) as Innovative Strategy for the Synthesis of Advanced Materials. Polymers (Basel) 2021; 13:1119. [PMID: 33915928 PMCID: PMC8036437 DOI: 10.3390/polym13071119] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 03/27/2021] [Accepted: 03/30/2021] [Indexed: 12/16/2022] Open
Abstract
Photochemistry has attracted great interest in the last decades in the field of polymer and material science for the synthesis of innovative materials. The merging of photochemistry and reversible-deactivation radical polymerizations (RDRP) provides good reaction control and can simplify elaborate reaction protocols. These advantages open the doors to multidisciplinary fields going from composite materials to bio-applications. Photoinduced Electron/Energy Transfer Reversible Addition-Fragmentation Chain-Transfer (PET-RAFT) polymerization, proposed for the first time in 2014, presents significant advantages compared to other photochemical techniques in terms of applicability, cost, and sustainability. This review has the aim of providing to the readers the basic knowledge of PET-RAFT polymerization and explores the new possibilities that this innovative technique offers in terms of industrial applications, new materials production, and green conditions.
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Affiliation(s)
| | - Roberto Simonutti
- Department of Materials Science, Università Degli Studi di Milano-Bicocca, Via R. Cozzi, 55, 20125 Milan, Italy;
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Fakhari A, Heshmat H, Emami Arjomand M, Tabatabaei SF. Influence of Light-Curing Units on Color Stability of Composite Resins After Aging. JOURNAL OF RESEARCH IN DENTAL AND MAXILLOFACIAL SCIENCES 2020. [DOI: 10.29252/jrdms.5.2.21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
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Yoo H, Kim H, Min SD, Lee O. Synchrotron radiation‐based analysis of fatigue in dental restorative materials. Microsc Res Tech 2020; 83:472-480. [DOI: 10.1002/jemt.23435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 11/26/2019] [Accepted: 12/17/2019] [Indexed: 12/15/2022]
Affiliation(s)
- Hyunjong Yoo
- Department of Computer Science & Engineering, Graduate SchoolSoonchunhyang University Asan City Republic of Korea
| | - Hongsik Kim
- Department of Dental TechnologyGimcheon University Gimcheon City Republic of Korea
| | - Se Dong Min
- Department of Computer Science & Engineering, Graduate SchoolSoonchunhyang University Asan City Republic of Korea
- Department of Medical IT EngineeringCollege of Medical Sciences, Soonchunhyang University Asan City Republic of Korea
| | - Onseok Lee
- Department of Computer Science & Engineering, Graduate SchoolSoonchunhyang University Asan City Republic of Korea
- Department of Medical IT EngineeringCollege of Medical Sciences, Soonchunhyang University Asan City Republic of Korea
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Evaluation of Light-Emitting Diodes' Effects on the Expression Level of P53 and EGFR in the Gingival Tissues of Albino Rats. ACTA ACUST UNITED AC 2019; 55:medicina55090605. [PMID: 31540512 PMCID: PMC6780216 DOI: 10.3390/medicina55090605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 09/15/2019] [Accepted: 09/16/2019] [Indexed: 11/16/2022]
Abstract
Background and objectives: The light-curing unit is considered an essential piece of equipment in every dental office. This study was conducted to evaluate the effect of Light-Emitting Diodes (LEDs) by the light cure (LC) device on gingival tissues of albino rats histologically and by regarding the expression of P53 and epidermal growth factor receptor (EGFR). Materials and methods: Gingival tissues of the rats were exposed to LEDs for 30 s with an interval of 30 s for periods of 2 and 5 min and were examined after two and four weeks of light exposure. After the set time, histological sections were studied and the P53 and EGFR expressions were evaluated immunohistochemically and by molecular methods. Results: Mild hyperplasia and mild inflammatory response were detected in higher rates after two weeks of exposure when compared to 4 weeks postexposure. Whereas fibrosis was found at a higher rate after four weeks than that found after two weeks postexposure, parakeratosis was seen only in the group that was exposed for 5 min to LC and when biopsies were taken after 2 weeks. We found that the immunohistochemical expression of P53 was not changed. Similarly, the alteration of EGFR expression was statistically nonsignificant (p > 0.05) when compared to the control group. The data obtained from the qRT-PCR reaction was analyzed using the comparative CT (2−ΔΔCT) method. Statistically, there was no significant difference in the expression of EGER and P53 gene transcripts. Conclusions: LED causes no serious alteration in P53 and EGFR expression, and only trivial histopathological changes occurred, most of which recovered after a 4-week interval.
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Efficacy of the LED Red Light Therapy in the Treatment of Temporomandibular Disorders: Double Blind Randomized Controlled Trial. PAIN RESEARCH AND TREATMENT 2019; 2019:8578703. [PMID: 31205787 PMCID: PMC6530159 DOI: 10.1155/2019/8578703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 03/02/2019] [Accepted: 04/08/2019] [Indexed: 11/18/2022]
Abstract
Background Temporomandibular dysfunction syndrome (TMD) is a common disease among dental patients. It occurs as a consequence of malfunction of the tempromandibular and/or surrounding facial muscles. LED red light therapy is not been well established, and it is important to find out the role of this technique in the treatment of temporomandibular disorders. Aim of the Study To evaluate the efficacy of the LED red light in the treatment of the tempromandibular dysfunction syndrome. Material and Methods Fifty students of the College of Dentistry/University of Baghdad with myofacial pain associated with Tempromandibular Disorder volunteered to participate in this study and be evaluated during both treatment and follow-up periods. They were 40 (80%) females and 10 (20%) males. Patients were divided into 2 groups: Group A treated by TenDlite® Medical Device model 204 with a LED's of wavelength 660 nm (red light) and Group B given placebo (no treatment at all) by just putting the TenDlite device near the tender points without battery and turning ON the device. Results The changes in the pain value and number of the tender muscles in both groups were highly significant, only placebo group less but with no significant differences. Conclusions This study showed that red LED therapy could be useful in improving patient's symptoms regarding pain, clicking, and number of tender muscles. In addition, this study showed the importance of the psychological part of treatment of those patients. This trial is registered with TCTR20190406002.
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Mastrangelo F, Perraro I, Mattia S, Troiano G, Zhurakivska K, Polizzi E, Chiesa R, Gherlone E, Lo Muzio L. Laser versus LED polymerization: Comparison of in vitro preventive sealing procedures. J Appl Biomater Funct Mater 2019; 17:2280800018816013. [DOI: 10.1177/2280800018816013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Introduction: The technique of sealing is a widely accepted procedure for prevention of caries. The aim of our in vitro study was to compare the effect of two different curing units (traditional LED source and innovative laser diode lamp) on the integrity of fissure sealant material and its interface with tooth enamel. Materials and methods: Sixty healthy third molars were randomly assigned to two groups. In group A were teeth intended for polymerization by LED B lamp, and group B comprised teeth to be polymerized by an innovative laser diode. Both groups were treated with the traditional sealing technique, subjected to a metallization process, and analyzed by scanning electron microscope. Results: Micro-gaps between the sealant and the enamel were found in specimens in both A (43%) and B (40%) groups ( p=0.793), and sealant shrinkage was seen. Significant differences between the groups emerged in the percentage of perimetric micro-erosion sites (80% vs. 100%, p=0.010) and the presence of holes and micro-bubbles on the sealant surface (21% vs. 63%, p=0.001). Conclusions: Although macroscopic clinical polymerization occurred with both instruments, the microscopic evaluation showed significant differences between the studied groups in terms of perimetric micro-erosion sites and micro-bubbles, which were higher in laser-cured samples.
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Affiliation(s)
- Filiberto Mastrangelo
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Isabella Perraro
- Department of Dentistry, Vita Salute University, IRCCS San Raffaele Hospital, Milan, Italy
| | - Sabrina Mattia
- Department of Dentistry, Vita Salute University, IRCCS San Raffaele Hospital, Milan, Italy
| | - Giuseppe Troiano
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Khrystyna Zhurakivska
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Elisabetta Polizzi
- Department of Dentistry, Vita Salute University, IRCCS San Raffaele Hospital, Milan, Italy
| | - Roberto Chiesa
- Department of Chemistry, Materials and Chemical Engineering “G. Natta,” Politecnico di Milano, Milan, Italy
| | - Enrico Gherlone
- Department of Dentistry, Vita Salute University, IRCCS San Raffaele Hospital, Milan, Italy
| | - Lorenzo Lo Muzio
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
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Guram G, Shaik JA. Comparison of Light-Emitting Diode-Curing Unit and Halogen-Based Light-Curing Unit for the Polymerization of Orthodontic Resins: An In vitro Study. J Int Soc Prev Community Dent 2018; 8:409-415. [PMID: 30430067 PMCID: PMC6187877 DOI: 10.4103/jispcd.jispcd_302_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 09/22/2017] [Indexed: 11/04/2022] Open
Abstract
Aims and Objectives Conventionally, composites are cured using halogen-based light-curing units (LCUs). However, recently, light-emitting diode (LED) LCUs have been introduced commercially, claiming many advantages, yet producing comparable bond strength even when cured with single LED LCUs. This present study was undertaken to compare the shear bond strength of orthodontic brackets bonded to teeth with conventional halogen LCU (3M ESPE Elipar 2500) and LED LCU (3M ESPE Elipar FreeLight 2) and to determine the site of bond failure. Materials and Methods Fifty extracted human bicuspid teeth were randomly divided into two groups of 25 each. All the teeth were etched and primed. Then, orthodontic brackets were bonded onto the teeth with the light-cured adhesive (Transbond XT, 3M Unitek), and the adhesive was cured with halogen LCU and LED LCU for Group I and Group II, respectively. The brackets were then subjected to shear stress using a Hounsfield universal testing machine at a crosshead speed of 1 mm/min. The force was recorded in Kgf and converted to MPa. The residual adhesive was scored based on the modified adhesive remnant index (ARI) using an optical stereomicroscope. The data were analyzed using the Student's t-test and the Mann-Whitney test at a significance level of 0.05. Results The results have shown that there is no significant difference between the shear bond strengths and the ARI scores of both the groups. Conclusion From this study, it can be concluded that (1) LED LCUs containing even only a single LED can cure the composite as well as a halogen-based LCU; (2) there is no statistically significant difference in the shear bond strengths of the two groups; and (3) the ARI scores show no significant difference.
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Affiliation(s)
- Guneet Guram
- Department of Orthodontics, Adesh Institute of Dental Sciences, Bathinda, Punjab, India
| | - Junaid Ahmed Shaik
- Department of Orthodontics, Adesh Institute of Dental Sciences, Bathinda, Punjab, India
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Use of Artificial Neural Network in Determination of Shade, Light Curing Unit, and Composite Parameters' Effect on Bottom/Top Vickers Hardness Ratio of Composites. BIOMED RESEARCH INTERNATIONAL 2018; 2018:4856707. [PMID: 30539012 PMCID: PMC6260521 DOI: 10.1155/2018/4856707] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/15/2018] [Accepted: 10/01/2018] [Indexed: 11/28/2022]
Abstract
Objective To assess the influence of light emitting diode (LED) and quartz tungsten halogen (QTH) light curing unit (LCU) on the bottom/top (B/T) Vickers Hardness Number (VHN) ratio of different composites with different shades and determination of the most significant effect on B/T VHN ratio of composites by shade, light curing unit, and composite parameters using artificial neural network. Method Three composite resin materials [Clearfil Majesty Esthetic (CME), Tetric N Ceram (TNC), and Tetric Evo Ceram (TEC)] in different shades (HO, A2, B2, Bleach L, Bleach M) were used. The composites were polymerized with three different LED LCUs (Elipar S10, Bluephase 20i, Valo) and halogen LCU (Hilux). Vickers hardness measurements were made at a load of 100 g for 10 sec on the top and bottom surfaces and B/T VHN ratio calculated. The data were statistically analyzed with three-way ANOVA and Tukey test at a significance level of 0.05. The obtained measurements and data were then fed to a neural network to establish the correlation between the inputs and outputs. Results There were no significant differences between the B/T VHN ratio of LCUs for the HO and B shades of CME (p>0.05), but there were significant differences between the B/T VHN ratio of LCUs for shade A2 (p<0.05). No significant difference was determined between the B/T VHN ratio of LCUs for all shades of TNC (p>0.05). For TEC, there was no significant difference between the B/T VHN ratio of halogen and LED LCUs (p>0.05), but a significant difference was determined among the LED LCUs (p<0.05). The artificial neural network results showed that a combination of the curing light and composite parameter had the most significant effect on the B/T VHN ratio of composites. Shade has the lowest effect on the B/T VHN ratio of composites. Conclusion The B/T VHN ratio values of different resin-based composite materials may vary depending on the light curing device. In addition, the artificial neural network results showed that the LCU and composite parameter had the most significant effect on the B/T VHN ratio of the composites. Shade has the lowest effect on the B/T VHN ratio of composites.
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Drost T, Reimann S, Frentzen M, Meister J. Effectiveness of photopolymerization in composite resins using a novel 445-nm diode laser in comparison to LED and halogen bulb technology. Lasers Med Sci 2018; 34:729-736. [PMID: 30291465 DOI: 10.1007/s10103-018-2651-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 09/27/2018] [Indexed: 11/25/2022]
Abstract
Challenges especially in the minimal invasive restorative treatment of teeth require further developments of composite polymerization techniques. These include, among others, the securing of a complete polymerization with moderate thermal stress for the pulp. The aim of this study is to compare current light curing sources with a blue diode laser regarding curing depth and heat generation during the polymerization process. A diode laser (445 nm), a LED, and a halogen lamp were used for polymerizing composite resins. The curing depth was determined according to the norm ISO 4049. Laser output powers of 0.1, 0.5, 1, and 2 W were chosen. The laser beam diameter was adapted to the glass rod of the LED and the halogen lamp (8 mm). The irradiation time was fixed at 40 s. To ascertain ΔT values, the surface and ground area temperatures of the cavities were simultaneously determined during the curing via a thermography camera and a thermocouple. The curing depths for the LED (3.3 mm), halogen lamp (3.1 mm) and laser(0.5/1 W) (3/3.3 mm) showed no significant differences (p < 0.05). The values of ΔTsurface as well as ΔTground also showed no significant differences among LED, halogen lamp, and laser(1 W). The ΔTsurface values were 4.1LED, 4.3halogen lamp, and 4.5 °C for the laser while the ΔTground values were 2.7LED, 2.6halogen lamp, and 2.9 °C for the laser. The results indicate that the blue diode laser (445 nm) is a feasible alternative for photopolymerization of complex composite resin restorations in dentistry by the use of selected laser parameters.
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Affiliation(s)
- Thomas Drost
- Department of Operative and Preventive Dentistry, Bonn University, Dental Faculty, Welschnonnenstrasse 17, 53111, Bonn, Germany
| | - Susanne Reimann
- Oral Technology, Bonn University, Dental Faculty, 53111, Bonn, Germany
| | - Matthias Frentzen
- Department of Operative and Preventive Dentistry, Bonn University, Dental Faculty, Welschnonnenstrasse 17, 53111, Bonn, Germany
| | - Jörg Meister
- Department of Operative and Preventive Dentistry, Bonn University, Dental Faculty, Welschnonnenstrasse 17, 53111, Bonn, Germany.
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Daugherty MM, Lien W, Mansell MR, Risk DL, Savett DA, Vandewalle KS. Effect of high-intensity curing lights on the polymerization of bulk-fill composites. Dent Mater 2018; 34:1531-1541. [DOI: 10.1016/j.dental.2018.06.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 05/25/2018] [Accepted: 06/07/2018] [Indexed: 10/28/2022]
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AlShaafi MM, AlQussier A, AlQahtani MQ, Price RB. Effect of Mold Type and Diameter on the Depth of Cure of Three Resin-Based Composites. Oper Dent 2018; 43:520-529. [DOI: 10.2341/17-122-l] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
Objective:
To evaluate the effects of different mold materials, their diameters, and light-curing units on the mechanical properties of three resin-based composites (RBC).
Methods and Materials:
A conventional nano-filled resin composite (Filtek Supreme Ultra, 3M Oral Care, St Paul, MN, USA) and two bulk-fill composites materials, Tetric Evoceram Bulk fill (Ivoclar Vivadent, Schaan, Liechtenstein) and Aura Bulk Fill (SDI, Bayswater, VIC, Australia), were tested. A total of 240 specimens were fabricated using metal or white semitransparent Delrin molds that were 4 or 10 mm in diameter. The RBCs were light cured for 40 seconds on the high-power setting of either a monowave (DeepCure-S, 3M Oral Care) or polywave (Bluephase G2, Ivoclar Vivadent) light-emitting diode (LED) curing unit. The depth of cure was determined using a scraping test, according to the 2009 ISO 4049 test method. Data were analyzed using multivariate analysis of variance followed by Tukey multiple comparison test (p<0.05).
Results:
In general, when used for 40 seconds, both LED curing lights achieved the same depth of cure (p=0.157). However, the mold material and its diameter had a significant effect on the depth of cure of all three RBCs (p<0.0001).
Conclusion:
Curing with either the polywave or monowave LED curing light resulted in the same depth of cure in the composites. The greatest depth of cure was always achieved using the 10-mm-diameter Delrin mold. Of the three RBCs tested, both Tetric Bulk Fill and Aura achieved a 4-mm depth of cure when tested in the 10-mm-diameter metal mold. Tetric Bulk Fill was the most transparent and had the greatest depth of cure, and the conventional composite had the least depth of cure. Very little violet (<420 nm) light penetrated through 6 mm of any of the RBCs.
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Affiliation(s)
- MM AlShaafi
- Maan M AlShaafi, BDS, MS, King Saud University, Restorative Dental Sciences, Riyadh, Saudi Arabia
| | - A AlQussier
- Anfal AlQussier, BDS, King Saud University, College of Dentistry, Restorative Dental Sciences, Riyadh, Saudi Arabia
| | - MQ AlQahtani
- Mohammed Q AlQahtani, BDS, MSD, King Saud University, College of Dentistry, Restorative Dental Sciences, Riyadh, Saudi Arabia
| | - RB Price
- Richard B Price, BDS, DDS, MS, PhD, FDS RCS (Edin), FRCD(C), Dalhousie University, Dental Clinical Sciences, Halifax, Canada
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Alberton Da Silva V, Alberton Da Silva S, Pecho OE, Bacchi A. Influence of composite type and light irradiance on color stability after immersion in different beverages. J ESTHET RESTOR DENT 2018; 30:390-396. [DOI: 10.1111/jerd.12383] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Simone Alberton Da Silva
- Department of Restorative Dentistry; Centro de Estudos Odontológicos Meridional - CEOM; Passo Fundo RS Brazil
| | - Oscar E. Pecho
- Post-graduate Program in Dentistry, Dental School; University of Passo Fundo; Passo Fundo RS Brazil
| | - Atais Bacchi
- Department of Prosthodontics and Dental Materials; Meridional Faculty - IMED; Passo Fundo RS Brazil
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Rodriguez A, Yaman P, Dennison J, Garcia D. Effect of Light-Curing Exposure Time, Shade, and Thickness on the Depth of Cure of Bulk Fill Composites. Oper Dent 2017; 42:505-513. [DOI: 10.2341/16-057-l] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
Purpose:
To investigate the effect of different light exposure times, shades, and thicknesses on the depth of cure (DOC) of bulk fill composites.
Methods and Materials:
Two bulk fill composites, Tetric EvoCeram Bulk Fill (TBF) and Sonic Fill (SF), and a conventional composite, Filtek Supreme Ultra (FSU), were evaluated. Samples (n=10) were made using two different shades (light and dark), thicknesses (2 and 4 mm) and exposure times (20 and 40 seconds). A Tukon 2100B-testing machine was used to obtain three Knoop hardness numbers (KHNs) measured at the top and bottom of each sample, and DOC was calculated as the bottom/top ratio. Statistical analysis was done using a Student t-test for comparisons between groups with a Bonferroni correction of p < 0.004.
Results:
Top hardness values ranged from 79.79 to 85.07 for FSU, 69.49 to 91.65 for SF, and 51.01 to 57.82 for TBF. Bottom KHNs ranged from 23.54 to 73.25 for FSU, 45.74 to 77.12 for SF, and 36.95 to 52.51 for TBF. TBF had the lowest overall KHNs. Light-curing exposure time, shade, and material thickness influenced the DOC in most groups, especially at 4-mm depths. A higher bottom/top ratio was achieved when a 40-second cure was compared to a 20-second cure, when light shades were compared to dark shades, and when 2-mm increments were compared to 4-mm increments.
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Affiliation(s)
- A Rodriguez
- Alexandra Rodriguez, DDS, MS, Department of Restorative Dentistry, University of Illinois at Chicago, Chicago, IL USA
| | - P Yaman
- Peter Yaman, DDS, MS, Department of Cariology, Restorative Sciences, and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - J Dennison
- Joseph Dennison, DDS, MS, Department of Cariology, Restorative Sciences, and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - D Garcia
- Daniela Garcia, DDS, MS, Department of Cariology, Restorative Sciences, and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
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17
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Degree of Conversion and Oxygen-Inhibited Layer Effect of Three Dental Adhesives. Dent J (Basel) 2016; 4:dj4040037. [PMID: 29563479 PMCID: PMC5806956 DOI: 10.3390/dj4040037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 09/22/2016] [Accepted: 10/03/2016] [Indexed: 11/29/2022] Open
Abstract
This study investigated the effect of the oxygen-inhibited layer on the degree of conversion (DC) of three dental adhesives, comparing two different protocols. Quartz–tungsten–halogen (QTH) light curing and light-emitting diode (LED) were used to cure three adhesives: OptiBond All in One (OAIO), Adper Easy Bond (AEB) and ExciteF (EXF). The DC was calculated utilizing Fourier Transform infrared spectroscopy (FTIR) (n = 12). The two protocols used were as follows: (i) prevent the oxygen-inhibited layer using a Mylar plastic strip pushed onto each bonding adhesive; and (ii) polymerize samples without a plastic strip. The data was analyzed statistically by a three-way ANOVA, and Tukey Test (a = 0.05). The presence of an oxygen-inhibited layer reduced the DC of the adhesives by 64% for EXF, 46% for AEB and 32% for OAIO. This study suggests that there are differences among the oxygen-inhibited layers present for the adhesives tested.
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Seo JH, Fushimi M, Matsui N, Takagaki T, Tagami J, Yui N. UV-Cleavable Polyrotaxane Cross-Linker for Modulating Mechanical Strength of Photocurable Resin Plastics. ACS Macro Lett 2015; 4:1154-1157. [PMID: 35614797 DOI: 10.1021/acsmacrolett.5b00619] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A UV-cleavable supramolecular cross-linker was designed to effectively control the mechanical strength of photocurable resin plastics. The resin monomer-soluble polyrotaxane (PRX) cross-linker was synthesized by introducing a hydrophobic n-butyl group and a cross-linkable methacrylate group in α-cyclodextrin threading to a polyethylene glycol containing UV-cleavable end groups. The UV-cleavable PRX cross-linker was completely dissolved in 2-hydroxyethytl methacrylate (HEMA) and camphorquinone, representative photocurable resin components. The dumbbell-like stiff resin plastic was prepared by irradiating the mixture with 450 nm blue light. The stiffened resin plastic maintained its ultimate tensile strength (UTS) under visible light irradiation. However, the UTS of the resin plastic was remarkably decreased to 40% of the original value once the plastic was exposed to 254 nm UV light. This indicates that the suggested UV-cleavable PRX cross-linker is effective in modulating the mechanical strength of photocurable resin plastics.
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Affiliation(s)
- Ji-Hun Seo
- Institute
of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo 101-0062, Japan
- Department
of Materials Science and Engineering, Korea University, Seoul 136-701, Korea
| | - Mayu Fushimi
- Institute
of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo 101-0062, Japan
| | - Naoko Matsui
- Cardiology
and Operative Dentistry, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Tomohiro Takagaki
- Cardiology
and Operative Dentistry, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Junji Tagami
- Cardiology
and Operative Dentistry, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Nobuhiko Yui
- Institute
of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo 101-0062, Japan
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Effect of increased exposure times on amount of residual monomer released from single-step self-etch adhesives. J Appl Biomater Funct Mater 2015; 13:e287-92. [PMID: 26108431 DOI: 10.5301/jabfm.5000235] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2015] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND The aim of this study was to evaluate the effect of increased exposure times on the amount of residual Bis-GMA, TEGDMA, HEMA and UDMA released from single-step self-etch adhesive systems. METHODS Two adhesive systems were used. The adhesives were applied to bovine dentin surface according to the manufacturer's instructions and were polymerized using an LED curing unit for 10, 20 and 40 seconds (n = 5). After polymerization, the specimens were stored in 75% ethanol-water solution (6 mL). Residual monomers (Bis-GMA, TEGDMA, UDMA and HEMA) that were eluted from the adhesives (after 10 minutes, 1 hour, 1 day, 7 days and 30 days) were analyzed by high-performance liquid chromatography (HPLC). The data were analyzed using 1-way analysis of variance and Tukey HSD tests. RESULTS Among the time periods, the highest amount of released residual monomers from adhesives was observed in the 10th minute. There were statistically significant differences regarding released Bis-GMA, UDMA, HEMA and TEGDMA between the adhesive systems (p<0.05). There were no significant differences among the 10, 20 and 40 second polymerization times according to their effect on residual monomer release from adhesives (p>0.05). CONCLUSIONS Increasing the polymerization time did not have an effect on residual monomer release from single-step self-etch adhesives.
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20
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The carbazole-bound ferrocenium salt as a specific cationic photoinitiator upon near-UV and visible LEDs (365–405 nm). Polym Bull (Berl) 2015. [DOI: 10.1007/s00289-015-1506-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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Mokbel H, Toufaily J, Hamieh T, Dumur F, Campolo D, Gigmes D, Pierre Fouassier J, Ortyl J, Lalevée J. Specific cationic photoinitiators for near UV and visible LEDs: Iodonium versus ferrocenium structures. J Appl Polym Sci 2015. [DOI: 10.1002/app.42759] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Haifaa Mokbel
- Institut de Science des Matériaux de Mulhouse IS2M; UMR CNRS 7361, UHA, rue Jean Starcky 68057 Mulhouse Cedex France
- Laboratoire de Matériaux, Catalyse, Environnement et Méthodes analytiques (MCEMA-CHAMSI), EDST, Université Libanaise, Campus Hariri; Hadath, Beyrouth Liban
| | - Joumana Toufaily
- Laboratoire de Matériaux, Catalyse, Environnement et Méthodes analytiques (MCEMA-CHAMSI), EDST, Université Libanaise, Campus Hariri; Hadath, Beyrouth Liban
| | - Tayssir Hamieh
- Laboratoire de Matériaux, Catalyse, Environnement et Méthodes analytiques (MCEMA-CHAMSI), EDST, Université Libanaise, Campus Hariri; Hadath, Beyrouth Liban
| | - Frederic Dumur
- Aix-Marseille Université, CNRS, Institut de Chimie Radicalaire ICR; UMR 7273 F-13397 Marseille France
| | - Damien Campolo
- Aix-Marseille Université, CNRS, Institut de Chimie Radicalaire ICR; UMR 7273 F-13397 Marseille France
| | - Didier Gigmes
- Aix-Marseille Université, CNRS, Institut de Chimie Radicalaire ICR; UMR 7273 F-13397 Marseille France
| | | | - Joanna Ortyl
- Faculty of Chemical Engineering and Technology; Cracow University of Technology; Warszawska 24 Cracow 31-155 Poland, and Photo HiTech Ltd. bobrzynskiego 14, Cracow 30-348, Poland
| | - Jacques Lalevée
- Institut de Science des Matériaux de Mulhouse IS2M; UMR CNRS 7361, UHA, rue Jean Starcky 68057 Mulhouse Cedex France
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22
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Sabatini C. Color Stability Behavior of Methacrylate-based Resin Composites Polymerized with Light-emitting Diodes and Quartz-Tungsten-Halogen. Oper Dent 2015; 40:271-81. [DOI: 10.2341/14-080-l] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
Despite significant developments in improving the optical properties of resin composite materials, their color stability remains a challenge. This study aimed to evaluate the shade stability of light-polymerized, methacrylate-based resin composites with different filler particle composition (microfill, minifill, nanohybrids, and microhybrids) polymerized with quartz-tungsten-halogen (QTH) and light-emitting diodes (LED).
Methods and Materials
Composite discs were fabricated from Tetric EvoCeram, Premise, Artiste, and Beautifil II (nanohybrids); Filtek Supreme Plus and Vit-l-escence (microhybrids); Heliomolar (microfill); and Estelite Sigma Quick (minifill) using a Teflon mold. The specimens were irradiated either with QTH (Elipar 2500; 600 mW/cm2) for 40 seconds or with LED (Bluephase G2; 1200 mW/cm2) for 20 seconds. Color parameters were measured with a colorimeter before and after polymerization and at 24 hours, one week, one month, and three months. Color change was calculated among the different storage periods.
Results
There was a significant effect of the composite, time, and their interaction (p<0.001) but no effect of the polymerization unit on the color stability. Color changes immediately after polymerization and at 24 hours (4.22 and 3.88 for LED; and 4.08 and 3.82 for QTH) were not significantly different from each other but were both significantly higher than changes after one week (0.96 and 0.78), one month (1.12 and 1.02), and three months (1.27 and 1.11) for LED and QTH, respectively (p<0.001).
Conclusions
Color changes were observed for all the materials that were dependent on the type of composite but not on the polymerization unit. These color shifts took place primarily immediately after polymerization and after 24 hours and were additive in nature.
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Affiliation(s)
- C Sabatini
- Camila Sabatini, DDS, MS, University at Buffalo, Restorative Dentistry, Buffalo, NY, USA
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23
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Kitchens B, Wells M, Tantbirojn D, Versluis A. Depth of cure of sealants polymerized with high-power light emitting diode curing lights. Int J Paediatr Dent 2015; 25:79-86. [PMID: 24628863 DOI: 10.1111/ipd.12102] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVE To determine whether recommended short curing times of three high-power light emitting diode (LED) curing lights are sufficient to polymerize sealant materials. METHODS Opaque-unfilled sealant (Delton LC Opaque), opaque-filled sealant (UltraSeal XT plus), and clear-filled sealant (FluroShield) were light cured in a covered slot-mold using the manufacturers' shortest recommended curing times with three high-power LED lights (3-s VALO, 5-s Fusion, 10-s Smartlite). A 40-s cure with a quartz-tungsten halogen (QTH) light was used as control. Vickers hardness was measured 24 h after curing at the sealant surface and through the depth (0.5 mm increments) (N = 10). Results were analyzed with two-way anova (pair-wise multiple comparisons, significance level 0.05). RESULTS The high-power LEDs did not cure the sealants as deep as the QTH. Delton LC Opaque showed the least depth of cure as hardness values beyond a depth of 0.5 mm were not measurable regardless of the curing light. Even for UltraSeal XT plus, when surface hardness was about the same with all lights, hardness decreased more rapidly with depth for the LEDs. FluroShield showed the slowest decline in hardness through the depth for all lights. CONCLUSIONS Manufacturers' recommendations for shortest possible curing time with high-power LEDs were not sufficient for adequate polymerization of the tested sealants.
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Affiliation(s)
- Brandon Kitchens
- Department of Pediatric Dentistry, College of Dentistry, University of Tennessee Health Science Center, Memphis, TN, USA
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Dietlin C, Schweizer S, Xiao P, Zhang J, Morlet-Savary F, Graff B, Fouassier JP, Lalevée J. Photopolymerization upon LEDs: new photoinitiating systems and strategies. Polym Chem 2015. [DOI: 10.1039/c5py00258c] [Citation(s) in RCA: 282] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The use of LEDs as novel and efficient light sources for the photopolymerization of various monomers (acylate, epoxy), interpenetrating polymer networks and thiols–ene, leads to the development of novel photoinitiating systems adapted for the LED emission.
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Affiliation(s)
- Céline Dietlin
- Institut de Science des Matériaux de Mulhouse IS2M
- UMR CNRS 7361
- 68057 Mulhouse Cedex
- France
| | - Stéphane Schweizer
- Institut de Science des Matériaux de Mulhouse IS2M
- UMR CNRS 7361
- 68057 Mulhouse Cedex
- France
| | - Pu Xiao
- Institut de Science des Matériaux de Mulhouse IS2M
- UMR CNRS 7361
- 68057 Mulhouse Cedex
- France
| | - Jing Zhang
- Institut de Science des Matériaux de Mulhouse IS2M
- UMR CNRS 7361
- 68057 Mulhouse Cedex
- France
| | - Fabrice Morlet-Savary
- Institut de Science des Matériaux de Mulhouse IS2M
- UMR CNRS 7361
- 68057 Mulhouse Cedex
- France
| | - Bernadette Graff
- Institut de Science des Matériaux de Mulhouse IS2M
- UMR CNRS 7361
- 68057 Mulhouse Cedex
- France
| | - Jean-Pierre Fouassier
- Institut de Science des Matériaux de Mulhouse IS2M
- UMR CNRS 7361
- 68057 Mulhouse Cedex
- France
| | - Jacques Lalevée
- Institut de Science des Matériaux de Mulhouse IS2M
- UMR CNRS 7361
- 68057 Mulhouse Cedex
- France
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25
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UV-violet-blue LED induced polymerizations: Specific photoinitiating systems at 365, 385, 395 and 405 nm. POLYMER 2014. [DOI: 10.1016/j.polymer.2014.11.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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26
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Sabatini C. Comparative study of surface microhardness of methacrylate-based composite resins polymerized with light-emitting diodes and halogen. Eur J Dent 2014; 7:327-335. [PMID: 24926213 PMCID: PMC4053622 DOI: 10.4103/1305-7456.115417] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Objective: The aim of this study was to evaluate the effect of polymerization with quartz-tungsten-halogen (QTH) and light-emitting diodes (LED) on the surface microhardness of eight commercially available light-polymerized, methacrylate-based composite resins, with different filler particle composition (microfill, minifill, nanohybrids, and microhybrids) immediately after polymerization, after 24 hours, and after three months of storage. Materials and Methods: Eighty disk-shaped specimens were prepared using a split Teflon mold (6 × 2 mm) and were irradiated with either the QTH (Elipar 2500; 600 mW/cm2) for 20 seconds or an LED (Bluephase G2; 1,200 mW/cm2) for 40 seconds. The microhardness values were recorded using a Vickers hardness tester at a 300 g load for 15 seconds, immediately after polymerization, after 24 hours, and after three months of dark aging in distilled water at 37°C. Statistical analysis was performed using a two-way analysis of variance (ANOVA) and the Tukey's test. Results: The baseline values demonstrated a significant effect of the composite and the interaction composite-LCU on the microhardness (P < 0.05). At 24 hours, only the composite variable showed a significant effect on the hardness values (P < 0.05). After three months, the composite, LCU, and the interaction composite-LCU all demonstrated a significant effect on the microhardness (P < 0.05). Conclusions: The effectiveness of polymerization, measured in terms of surface hardness, was shown to be dependent not only on the type of light curing unit, but also on the type of composite. Moreover, the choice of composite was shown to affect the performance of the light curing unit.
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Affiliation(s)
- Camila Sabatini
- Department of Restorative Dentistry, School of Dental Medicine, SUNY at Buffalo, Buffalo, NY, USA
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27
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Aleixo AR, Guiraldo RD, Fugolin APP, Berger SB, Consani RLX, Correr AB, Gonini-Júnior A, Lopes MB. Evaluation of contraction stress, conversion degree, and cross-link density in low-shrinkage composites. Photomed Laser Surg 2014; 32:267-73. [PMID: 24708062 DOI: 10.1089/pho.2013.3678] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE The contraction stress, degree of conversion, and cross-link density (CLD) of the Venus Diamond (low-shrinkage), Filtek P90 (low-shrinkage) and Filtek Z350 XT composites were evaluated after photopolymerization by quartz tungsten halogen or light-emitting diode light curing units. MATERIALS AND METHODS Contraction stress measurements were performed on 60 samples fabricated in rings of photoelastic resin. The adhesive was applied and photoactivated, followed by insertion and photoactivation of the composites. The contraction stress (MPa) was measured using a polariscope. The measurements of degree of conversion (%DC) were determined from Fourier transform infrared (FTIR) spectra of the top and bottom surfaces on 60 specimens. Cross-link density was estimated from hardness measurements performed at the top and bottom surfaces on 60 specimens. The Knoop hardness number was measured, and the specimens were placed in absolute ethanol for 24 h. The hardness was again determined and the CLD was estimated from the percentage decrease in hardness (PD) occurring during ethanol exposure for each surface. The contraction stress and PD data were subjected to ANOVA and Tukey's test (5%). The DC data were subjected to one way analysis of variance on ranks followed by pairwise multiple comparisons using Tukey's test (5%). RESULTS The Venus Diamond composite exhibited lower contraction stress than other composites, with degrees of conversion similar to those of Filtek Z350 XT at both surfaces, and independent of the light curing unit. The PD value of Venus Diamond was also lower than that for the other composites. CONCLUSIONS The low-shrinkage Venus Diamond composite may potentially reduce stress at the restoration/tooth interface.
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Affiliation(s)
- Anderson Rafael Aleixo
- 1 Department of Restorative Dentistry, School of Dentistry, University of North Parana , Londrina, PR, Brazil
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Chandurkar AM, Metgud SS, Yakub SS, Kalburge VJ, Biradar BC. Comparative Evaluation of the Effects of Light Intensities and Curing Cycles of QTH, and LED Lights on Microleakage of Class V Composite Restorations. J Clin Diagn Res 2014; 8:221-4. [PMID: 24783142 DOI: 10.7860/jcdr/2014/7463.4167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Accepted: 02/17/2014] [Indexed: 11/24/2022]
Abstract
BACKGROUND The purpose of this study was to evaluate the effects of light intensity and curing cycles of QTH and LED lights on the microleakage of Class V composite restorations. MATERIALS AND METHODS Eighty freshly extracted human maxillary premolars were used for this study. Standardized Class V cavities were prepared and they were restored with microhybrid resin composite. According to the curing protocol, the teeth were then divided into 4 groups (n=20): QTH curing (standard and soft start modes), and LED (standard and soft start modes) irradiations. Microleakage was evaluated by immersion of the samples in 50% silver nitrate solution. The samples were then sectioned, evaluated under a stereomicroscope, and scored for microleakage. RESULTS The results of the present in-vitro study showed mean dye leakage scores of 1.9, 1.2, 1.45 and 0.90 for Group I (QTH-Standard mode), Group II (QTH-Soft Start mode), Group III (LED-Standard mode) and Group IV (LED-Soft Start mode) respectively. CONCLUSION It was thus concluded that the soft start polymerization showed a highly significant difference as compared to the standard curing modes of QTH and LED lights, respectively.
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Affiliation(s)
- Anshu M Chandurkar
- Assistant Professor, Department of Conservative Dentistry and Endodontics, Rural Dental College , Pravara Medical Trust, India
| | - Sandeep S Metgud
- Professor, Department of Conservative Dentistry and Endodontics, Pacific Dental College , Udaipur, Rajasthan, India
| | - Shaikh Shoeb Yakub
- Professor, Department of Conservative Dentistry and Endodontics, Rural Dental College , Pravara Medical Trust, India
| | - Vaishali J Kalburge
- Assistant Professor, Department of Conservative Dentistry and Endodontics, Siddhpur Dental College and Research Centre , Siddhpur, India
| | - Basawaraj C Biradar
- Reader, Department of Conservative Dentistry and Endodontics, Rural Dental College , Pravara Medical Trust, India
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Panhoca VH, Lizarelli RDFZ, Nunez SC, Pizzo RCDA, Grecco C, Paolillo FR, Bagnato VS. Comparative clinical study of light analgesic effect on temporomandibular disorder (TMD) using red and infrared led therapy. Lasers Med Sci 2013; 30:815-22. [PMID: 24197518 DOI: 10.1007/s10103-013-1444-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 09/16/2013] [Indexed: 11/28/2022]
Abstract
Low-level laser therapy (LLLT) has been widely applied in pain relief in several clinical situations, including temporomandibular disorders (TMD). However, the effects of LED therapy on TMD has not been investigated. This study aims to evaluate the effects of red and infrared LEDs on: (1) tissue temperature in ex vivo and (2) pain relief and mandibular range of motion in patients with TMD. Thirty patients between 18 and 40 years old were included and randomly assigned to three groups. The two experimental groups were: the red LED (630 ± 10 nm) group and the infrared LED (850 ± 10 nm) group. The irradiation parameters were 150 mW, 300 mW/cm(2), 18 J/cm(2), and 9 J/point. The positive control group received an infrared laser (780 nm) with 70 mW, 1.7 W/cm(2), 105 J/cm(2), and 4.2 J/point. LED and laser therapies were applied bilaterally to the face for 60 s/point. Five points were irradiated: three points around the temporomandibular joint (TMJ), one point for the temporalis, and one near the masseter. Eight sessions of phototherapy were performed, twice a week for 4 weeks. Pain induced by palpating the masseter muscle and mandibular range of motion (maximum oral aperture) were measured at baseline, immediately after treatment, 7 days after treatment, and 30 days after treatment. There was an increase in tissue temperature during both the red and the infrared LED irradiation in ex vivo. There was a significant reduction of pain and increase of the maximum oral aperture for all groups (p ≥ 0.05). There was no significant difference in pain scores and maximum oral aperture between groups at baseline or any periods after treatment (p ≥ 0.05). The current study showed that red and infrared LED therapy can be useful in improving outcomes related to pain relief and orofacial function for TMD patients. We conclude that LED devices constitute an attractive alternative for LLLT.
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Affiliation(s)
- Vitor Hugo Panhoca
- Optics Group from Physics Institute of São Carlos (IFSC), University of São Paulo (USP), Brazil. Av. Trabalhador Sancarlense, 400-Centro, 13560-970, São Carlos, SP, Brazil,
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de Moraes Porto ICC, Ramos de Brito AC, Parolia A. Effect of cross infection control barriers used on the light-curing device tips on the cure depth of a resin composite. J Conserv Dent 2013; 16:224-8. [PMID: 23833455 PMCID: PMC3698585 DOI: 10.4103/0972-0707.111319] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Revised: 02/12/2013] [Accepted: 02/26/2013] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Among the advice on prevent cross-infection was included usage of mechanical barriers on tips of photoactivation units. However, questions about the use of protective barriers placed on the light-curing unit's tips and the possibility of interference with the ability of guaranteeing an effective polymerization of composite resins need to be clarified. AIMS The aim of this study was to evaluate the effect of cross infection control barriers used on the light-curing device tips on the cure depth of composite resin. MATERIALS AND METHODS Power density measurements from the light-cure unit were recorded with a radiometer on ten separate occasions with different types and placement modes of each barrier (low-density polyethylene and polyvinyl chloride (PVC) film - smooth and folds) and no-barrier (control). Cure depth of TPH™ Spectrum™ resin, A2-A4, was evaluated by the scraping test. STATISTICAL ANALYSIS The data were analyzed using Student's t-test or ANOVA one-way with Tukey's test (α =0.05). RESULTS Same type of barrier and different shades (A2, A4) of composite exhibited significant difference in the cure depth among all groups (P < 0.05). Both low-density polyethylene and PVC film folded barriers produced a significant reduction in the light intensity (P < 0.05). CONCLUSIONS Regarding the resin shade, there was a significant reduction in the cure depth of A4 composite resin (dark shade) but this reduction is not enough to cause any adverse effect on the material's clinical performance. Therefore, disposable barriers can be recommended for use over the end of the light guide.
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Affiliation(s)
- Isabel Cristina Celerino de Moraes Porto
- Department of Restorative Dentistry, Federal University of Alagoas, Maceió, Alagoas, Brazil ; Department of Restorative Dentistry, Cesmac University Center, Maceió, Alagoas, Brazil
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Carvalho PEG, Santos VMD, Isber H, Cotrim-Ferreira FA. Halogen light versus LED for bracket bonding: shear bond strength. Dental Press J Orthod 2013; 18:31.e1-6. [DOI: 10.1590/s2176-94512013000100007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
INTRODUCTION: LED light-curing devices seek to provide a cold light activator which allows protocols of material polymerization with shorter duration. OBJECTIVE: The present study aimed to evaluate the shear bond strength of bracket bonding using three types of light-curing devices: One with halogen light (Optilight Plus - Gnatus) and two with LEDs (Optilight CL - Gnatus and Elipar Freelight - 3M/ESPE). RESULTS: Comparing the results by analysis of variance, the Gnatus LED device showed an inferior statistical behavior in relation to other light sources, when activated by a short time. But, when it was used for 40 seconds, the polymerization results were consistent with the other evaluated sources. The device with the best average performance was the halogen light, followed by the 3M/ESPE LED. CONCLUSION: It was concluded that the LEDs may be indicated in orthodontic practice, as long as a protocol is used for the application of light with the activation time of 40 seconds.
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Effect of light polymerization time, mode, and thermal and mechanical load cycling on microleakage in resin composite restorations. Lasers Med Sci 2013; 29:545-50. [PMID: 23314786 DOI: 10.1007/s10103-012-1244-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Accepted: 12/04/2012] [Indexed: 10/27/2022]
Abstract
This study evaluated the effect of polymerization mode and time and thermal and mechanical loading cycling (TMC) on microleakage in composite resin restorations. One hundred and eighty cavities were prepared and randomly divided according to the light curing time (20, 40, or 60 s), modes (quartz-tungsten-halogen (QTH)-420 mW/cm(2), LED 2 (2nd degree generation)-1,100 mW/cm(2), or LED 3 (3rd degree generation)-700 mW/cm(2)), and TMC. Following standard restorative procedures, the samples were prepared for analysis in an absorbance spectrophotometer. All results were statistically analyzed using the three-way ANOVA and Tukey test (p ≤ 0.05). The results revealed that the groups QTH and LED 3 submitted to TMC showed higher microleakage than those that were not submitted to TMC. Only for LED 3, 60 s showed higher microleakage than 20 s. For LED 2 and QTH, there were no differences between the times. QTH showed lower microleakage means than LED 2, when photoactivated for 20 s, without TMC. When photoactivated for 60 s, QTH showed lower microleakage means than LED 3, for the groups with or without TMC. It was concluded that TMC, the increase in polymerization time, and the irradiance were factors that may increase the marginal microleakage of class II cavities.
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Gaglianone LA, Lima AF, Araújo LSND, Cavalcanti AN, Marchi GM. Influence of different shades and LED irradiance on the degree of conversion of composite resins. Braz Oral Res 2012; 26:165-9. [DOI: 10.1590/s1806-83242012005000002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2011] [Accepted: 01/04/2012] [Indexed: 11/21/2022] Open
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Gaglianone LA, Lima AF, Gonçalves LS, Cavalcanti AN, Aguiar FHB, Marchi GM. Mechanical properties and degree of conversion of etch-and-rinse and self-etch adhesive systems cured by a quartz tungsten halogen lamp and a light-emitting diode. J Mech Behav Biomed Mater 2012; 12:139-43. [PMID: 22728468 DOI: 10.1016/j.jmbbm.2012.01.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 01/18/2012] [Accepted: 01/24/2012] [Indexed: 10/28/2022]
Abstract
The aim of the present study was to evaluate the degree of conversion (DC), elastic modulus (E), and flexural strength (FS) of five adhesive systems (only the bonding component of both Scotchbond MP-SBMP and Clearfil Protect Bond-CP; Single Bond 2-SB2; One-up Bond F Plus-OUP; and P90 System Adhesive: primer-P90P and bond-P90B) cured with a quartz tungsten halogen (QTH) lamp and a light-emitting diode (LED). Two groups per adhesive were formed (n=5), according to the light source (quartz tungsten halogen-QTH: Demetron LC; and light-emitting diode-LED: UltraLume 5). Bar-shaped specimens were evaluated using three-point bending. The DC was obtained by Fourier transform infrared spectroscopy (FTIR). SB2 and P90P exhibited better DC values for QTH curing. However, SB2 and P90P presented the worst results overall. The light source was statistically significant for all adhesives, except for P90B and OUP. Non-solvated adhesives presented the best E and FS values. It could be concluded that the DC and E values can be influenced by the light source; however, this interference is material dependent.
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Affiliation(s)
- Lívia Aguilera Gaglianone
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av. Limeira, 901 - Areião, 13414-903 Piracicaba, SP, Brazil.
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Frauscher KE, Ilie N. Depth of cure and mechanical properties of nano-hybrid resin-based composites with novel and conventional matrix formulation. Clin Oral Investig 2011; 16:1425-34. [DOI: 10.1007/s00784-011-0647-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 11/16/2011] [Indexed: 10/15/2022]
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Guiraldo RD, Consani S, Consani RLX, Bataglia MPDC, Fugolin APP, Berger SB, Lopes MB, Moura SK, Sinhoreti MAC. Evaluation of the light energy transmission and bottom/top rate in silorane and methacrylate-based composites with different photoactivation protocols. J Contemp Dent Pract 2011; 12:361-7. [PMID: 22269197 DOI: 10.5005/jp-journals-10024-1060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
AIM This study investigated the influence of different composite resin organic matrix (methacrylate - Filtek Z350 XT and silorane - Filtek P90) on light energy transmission through the composite and bottom/top rate. MATERIALS AND METHODS A light-emitting diode (New Blue Phase), light-curing unit was used with different photoactivation protocols (high-continuous mode - HCM, 1400 mW/cm2 for 20 seconds; low-continuous mode - LCM , 700 mW/cm2 for 40 seconds; and soft-start mode - SSM, 140 mW/cm2 for 5s followed by 39 seconds for 700 mW/cm2). Twenty specimens were prepared for each composite. The light energy transmission through the composite was calculated (n=10). The bottom/top rate of the same specimen was calculated (n=10). The data were compared by Tukey's test in different tests (light energy transmission through the composite and bottom/top rate). RESULTS The light energy transmission through the Filtek Z350 XT composite (HCM - 576 mW/cm2, LCM - 238 mW/cm2, SSM - 232 mW/cm2) did not show statistical difference when compared with Filtek P90 composite (HCM - 572 mW/cm2, LCM - 233 mW/cm2, SSM - 230 mW/cm2). The bottom/top rate of the Filtek Z350 XT composite (HCM - 88.98%, LCM - 90.94%, SSM - 89.92%) was statistically higher than that of the Filtek P90 composite (HCM-77.29%, LCM-77.51%, SSM- 77.79%). CONCLUSION Light energy transmission through the composite was not influenced by the use of different dental composite restoratives. However, the bottom/top rate of the composites was influenced by the use of different dental composite restoratives. CLINICAL SIGNIFICANCE Insufficiently polymerized composite resin may present a large number of problems. For this reason, dental composite resins should have the similar deep surface polymerization as the top surface in dental restorations.
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dos Santos REA, Lima AF, Soares GP, Ambrosano GMB, Marchi GM, Lovadino JR, Aguiar FHB. Effect of preheating resin composite and light-curing units on the microleakage of Class II restorations submitted to thermocycling. Oper Dent 2011; 36:60-5. [PMID: 21488730 DOI: 10.2341/10-226-lr1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This in vitro study evaluated microleakage in Class II cavities restored with dental composite and varying light-curing units and the temperature of the composite when subjected to a thermocycling test. Ninety cavities were prepared on the proximal surfaces of bovine teeth and randomly divided according to the light-curing mode (QTH-420 mW/cm2, LED 2nd generation-1100 mW/cm2, or LED 3rd generation-700 mW/cm2) and temperature of the resin composite (23°C, 54°C and 60°C). Following the restorative procedures and thermocycling, the samples were immersed in methylene blue for 12 hours. The samples were ground and the powder prepared for analysis in an absorbance spectrophotometer. All the results were statistically analyzed using the nonparametric tests of Kruskal-Wallis and Dunn (p ≤ 0.05). The results showed that there was no statistical difference between the light-curing modes at a temperature of 23°C. For 54°C, QTH showed a microleakage mean that was significantly lower than those of the LED groups, and for 60°C, QTH had a microleakage mean significantly lower than that of the LED 2nd generation group. There was no statistical difference between the temperatures of the resin composite when LEDs were used. For QTH, 54°C showed statistically lower microleakage than 23°C. The group preheated to 60°C showed no difference when compared to the group heated to 23°C. Preheating the resin composite (54°C and 60°C) did not improve the microleakage means when high-irradiance LED was used; however, it decreased the microleakage means when a QTH with low irradiance was used.
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Faria-e-Silva AL, Lima AF, Moraes RR, Piva E, Martins LR. Degree of Conversion of Etch-and-Rinse and Self-etch Adhesives Light-cured Using QTH or LED. Oper Dent 2010; 35:649-54. [DOI: 10.2341/10-066-l] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
The effect of QTH and LED curing lights on the degree of conversion of bonding agents is material dependent.
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Rahiotis C, Patsouri K, Silikas N, Kakaboura A. Curing efficiency of high-intensity light-emitting diode (LED) devices. J Oral Sci 2010; 52:187-95. [PMID: 20587941 DOI: 10.2334/josnusd.52.187] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
We evaluated the curing efficiency of 4 high-intensity light-emitting diode (LED) devices by assessing percentage of residual C=C (%RDB), surface microhardness (SM), depth of cure (DC), percentage of linear shrinkage-strain (%LS), and percentage of wall-to-wall contraction (%WWC). The light-curing units tested were a QTH light, the Elipar TriLight (3M/ESPE), and 4 LED devices - the Allegro (Denmat), the Bluephase (Ivoclar/Vivadent), the FreeLight2 (3M/ESPE), and The Cure TC-01 (Spring Health Products). The %RDB was measured by microFTIR spectroscopy. Microhardness measurements (Vickers) were performed at the surface (H0) and at depths of 3 mm (H3) and 5 mm (H5) of cylindrical specimens. Depth of cure was expressed as the ratio of microhardness at each depth, relative to the corresponding surface value (H3/H0 and H5/H0). The bonded disc method was used to evaluate %LS. For the %WWC evaluation, cylindrical resin restorations were imaged by high resolution micro-CT and the %WWC was calculated at depths of 0 mm and 2 mm. There were no statistical differences among the LEDs in %RDB or %LS. The Bluephase and Allegro had the highest SM values. As compared with the other LEDs, the Bluephase and The Cure TC-01 had lower values for depth of cure at depths of 3 mm and 5 mm. There were no significant differences in %WWC among the LEDs at either depth, and the QTH had the lowest %WWC at both depths.
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Affiliation(s)
- Christos Rahiotis
- Department of Oral Biology, Faculty of Dentistry, University of Athens, Goudi, Greece.
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Retamoso LB, Onofre NML, Hann L, Marchioro EM. Effect of light-curing units in shear bond strength of metallic brackets: an in vitro study. J Appl Oral Sci 2010; 18:68-74. [PMID: 20379684 PMCID: PMC5349030 DOI: 10.1590/s1678-77572010000100012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2008] [Accepted: 08/11/2009] [Indexed: 12/03/2022] Open
Abstract
Objective To determine the influence of the light curing units on the shear bond strength of
orthodontic brackets. Material and Methods Seventy-two premolars were divided into six groups (n=12): Group I: brackets
bonded with Transbond and polymerization with halogen light; Group II: Transbond
and LED; Group III: Fuji Ortho and halogen light; Group IV: Fuji Ortho and LED;
Group V: Fuji Ortho, without acid and halogen light; Group VI: Fuji Ortho, without
acid and LED. The groups were tested to shear strength in a universal testing
machine at a crosshead speed of 0.5 mm/min. Data were analyzed statistically by
ANOVA and Tukey’s test. Results The composite resin presented higher shear bond strength than the resin-modified
glass ionomer cement (p<0.05). The halogen light and LED sources produced
similar shear bond strength (p>0.05). Conclusion The shear bond strength was influenced by the material but not by the light-curing
unit. The use of LED reduced the experimental time by approximately 60%, with the
same curing efficiency.
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Guiraldo RD, Consani S, Consani RLX, Berger SB, Mendes WB, Sinhoreti MAC. Light energy transmission through composite influenced by material shades. THE BULLETIN OF TOKYO DENTAL COLLEGE 2010; 50:183-90. [PMID: 20179393 DOI: 10.2209/tdcpublication.50.183] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This study investigated the influence of different composite resin shades on light energy transmission through the composite, hardness and cross-link density (CLD). The composite Filtek Z250 was used in shades A1, A2, A3, A3.5 and A4. A quartz tungsten halogen light curing unit was used at an irradiance of 900 mW/cm(2). Thirty specimens were made for each shade. Light energy transmission that passed through the composite was calculated (n=10). Differences in Knoop hardness between the top and bottom (DKH) of the same specimen were calculated (n=10). The Knoop hardness value for each surface was recorded as the average of three indentations (KHN(1)). Thereafter, the specimens were soaked in absolute ethanol for 24hr at room temperature, and hardness was again determined (KHN(2)). The CLD was estimated by the softening effect produced by ethanol, i.e., by decrease in hardness. The percentage of decrease in KHN(2) compared with KHN(1) (PD) in the same specimen was then calculated for both surfaces (n=10). The data were submitted to an ANOVA in different tests (Light energy transmission, Knoop hardness and CLD). The irradiance of light that passed through composite shade A1 (408 mW/cm(2)) was statistically greater than that through shade A2 (376 mW/cm(2)), and was greater through A2 than A3 (359 mW/cm(2)) and through A3 than A3.5 (327 mW/cm(2)); A3.5 showed no statistical difference when compared to A4 (324 mW/cm(2)). The DKH of A4 (20.56%) was not statistically higher than that of A3.5 (20.14%), which was greater than that of A3 (14.08%), A2 (11.65%) and A1 (9.06%). There was no statistical difference in CLD. Darker shades had a significant influence on light energy transmission through dental resin composite and its hardness. However, CLD was not affected by darker dental composite shades.
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Monte Alto RV, Guimarães JGA, Poskus LT, da Silva EM. Depth of cure of dental composites submitted to different light-curing modes. J Appl Oral Sci 2009; 14:71-6. [PMID: 19089034 PMCID: PMC4327445 DOI: 10.1590/s1678-77572006000200002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2004] [Accepted: 12/21/2005] [Indexed: 11/21/2022] Open
Abstract
Objective: This study evaluated the depth of cure of five dental composites submitted to different light-curing modes. Material and Methods: Canal-shaped cavities with 5mm of length were prepared on the buccal surfaces of extracted third molars, and restored using P-60, A-110, Admira, Z-250 and Supreme resin composites. Materials were light-cured from the top, according to three modes (Group 1- Conventional (C): 500 mW/cm2/ 40 s; Group 2 – Soft-Start (SS):250 mW/cm2/ 20 s + 500 mW/cm2/ 20 s + 500 mW/cm2/ 10 s and Group 3 – LED: 250 mW/cm2/ 40 s). After that, cavity longitudinal surfaces were polished and marked with a millimeter scale of 4mm of length. Depth of cure was evaluated by means of Knoop hardness number (KHN), so that five indentations were performed at each millimeter. Original data were submitted to three-way ANOVA and Fisher's LSD test (α = 0.01). Results: All materials presented a significant reduction on KHN from first to third millimeter. Regarding depth of cure, the results obtained for Conventional and Soft-Start modes were similar, but statistically superiors to those found for group 3 (LED). Conclusion: This performance may be related to the differences among energy densities obtained with different light-curing modes.
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Affiliation(s)
- Raphael Vieira Monte Alto
- Department of Restorative Dentistry, School Of Dentistry, Federal Fluminense University, Ingá, Niterói, RJ
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Cerveira GP, Berthold TB, Souto AA, Spohr AM, Marchioro EM. Degree of conversion and hardness of an orthodontic resin cured with a light-emitting diode and a quartz-tungsten-halogen light. Eur J Orthod 2009; 32:83-6. [DOI: 10.1093/ejo/cjp048] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Calabrez-Filho S, Calabrez VCN, Reston EG, Andrade MF, Borges LH. Influence of the Internal Conditioning of Indirect Restorations of Resin Composite in Relation to Microleakage Using LEDs and QTH Units. Oper Dent 2009; 34:293-8. [DOI: 10.2341/08-83] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
An efficient polymerization of resin composite inlays associated with treatment of the surface and luting with dual resinous cement and flowable resin composites presents better longevity of restorations.
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Mousavinasab SM, Meyers I. Curing efficacy of light emitting diodes of dental curing units. J Dent Res Dent Clin Dent Prospects 2009; 3:11-6. [PMID: 23230474 PMCID: PMC3517196 DOI: 10.5681/joddd.2009.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2008] [Accepted: 01/28/2009] [Indexed: 11/29/2022] Open
Abstract
Background and aims
The aim of the present study was to compare the efficacy of quartz tungsten halogen (QTH) and light emitting diode (LED) curing lights on polymerization of resin composite.
Materials and methods
A hybrid resin composite was used to prepare samples which were cured using two QTH and ten LED light curing sources. Twelve groups, each containing ten samples, were prepared using each light source. The cured depth of the resin was determined using ISO 4049 method and Vickers hardness values were determined at 1.0 mm intervals. Data was analyzed by ANOVA and Tukey test.
Results
Data analysis demonstrated a significant difference between light sources for depth of cure. At 1.0 mm below the surface all the tested light sources and at 2.0-mm intervals all light sources except two (Optilux 501 and LEDemetron I) and at 3.0-mm intervals only two light sources (PenCure and LEDemetron II) could produce hardness values higher than 80% of superficial layer values.
Conclusion This study showed that a variety of LED light sources used in the present study are as effective as the high-intensity QTH lights in polymerization of resin composite.
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Affiliation(s)
- Seyed Mostafa Mousavinasab
- Associate Professor, Department of Restorative Dentistry and Torabinejad Research Center, School of Dentistry, Isfahan University of Medical Sciences and Khorasgan Azad University, Isfahan, Iran
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Lopes LG, Franco EB, Pereira JC, Mondelli RFL. Effect of light-curing units and activation mode on polymerization shrinkage and shrinkage stress of composite resins. J Appl Oral Sci 2009; 16:35-42. [PMID: 19089287 PMCID: PMC4327278 DOI: 10.1590/s1678-77572008000100008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The aim of this study was to evaluate the polymerization shrinkage and shrinkage stress of composites polymerized with a LED and a quartz tungsten halogen (QTH) light sources. The LED was used in a conventional mode (CM) and the QTH was used in both conventional and pulse-delay modes (PD). The composite resins used were Z100, A110, SureFil and Bisfil 2B (chemical-cured). Composite deformation upon polymerization was measured by the strain gauge method. The shrinkage stress was measured by photoelastic analysis. The polymerization shrinkage data were analyzed statistically using two-way ANOVA and Tukey test (p≤0.05), and the stress data were analyzed by one-way ANOVA and Tukey's test (p≤0.05). Shrinkage and stress means of Bisfil 2B were statistically significant lower than those of Z100, A110 and SureFil. In general, the PD mode reduced the contraction and the stress values when compared to CM. LED generated the same stress as QTH in conventional mode. Regardless of the activation mode, SureFil produced lower contraction and stress values than the other light-cured resins. Conversely, Z100 and A110 produced the greatest contraction and stress values. As expected, the chemically cured resin generated lower shrinkage and stress than the light-cured resins. In conclusion, The PD mode effectively decreased contraction stress for Z100 and A110. Development of stress in light-cured resins depended on the shrinkage value.
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Affiliation(s)
- Lawrence Gonzaga Lopes
- Department of Preventive and Oral Reabilitation, Dental School, Federal University of Goiás, Goiânia, GO, Brazil
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RUEGGEBERG FREDERICKA, COLE MEGANA, LOONEY STEPHENW, VICKERS AARON, SWIFT EDWARDJ. Comparison of Manufacturer-Recommended Exposure Durations with Those Determined Using Biaxial Flexure Strength and Scraped Composite Thickness Among a Variety of Light-Curing Units. J ESTHET RESTOR DENT 2009; 21:43-61. [DOI: 10.1111/j.1708-8240.2008.00231.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Cunha LG, Alonso RCB, Neves ACC, de Goes MF, Ferracane JL, Sinhoreti MAC. Degree of Conversion and Contraction Stress Development of a Resin Composite Irradiated Using Halogen and LED at Two C-factor Levels. Oper Dent 2009; 34:24-31. [DOI: 10.2341/08-32] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
Curing methods using lower irradiance levels were shown to be effective in reducing the rate of stress generation without compromising the conversion of the restorative composite. Higher C-factor was shown to enhance the stress rate and amount of stress generated.
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Temperature rise and degree of photopolymerization conversion of nanocomposites and conventional dental composites. Clin Oral Investig 2008; 13:309-16. [DOI: 10.1007/s00784-008-0236-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Accepted: 11/24/2008] [Indexed: 10/21/2022]
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Abstract
The new generation LED curing light units have significantly improved curing performance compared to first generation lights, and even some second generation LED curing light units. This study compared the curing performance of 10 new generation LED light curing units (FLASH-lite 1401, LE Demetron 1, Coltolux, Ultra-Lume 5, Mini LED, bluephase, Elipar FreeLight 2, Radii, Smartlite IQ and Allegro) for depth of cure against a high-powered halogen curing light unit (Optilux 501). Depth of cure measurements were utilized per the ANSI/ADA No 27 standard to detect differences between the lights at three time intervals (10, 20 and 40 seconds). A total of 660 samples were prepared (n=10/group). A full factorial ANOVA and Tukey's HSD test showed FLASH-lite 1401 performed significantly better than the other lights at 10- and 20-second time intervals (p<0.01). This study also demonstrated that an exposure time of 20 seconds or longer assures a better depth of cure, 40 seconds being the optimal polymerization time for all of the curing light units.
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Affiliation(s)
- Sibel A Antonson
- Department of Restorative Dentistry, School of Dental Medicine, State University of New York at Buffalo, Buffalo, NY, USA.
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