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Zattera ACA, Morganti FA, de Souza Balbinot G, Della Bona A, Collares FM. The influence of filler load in 3D printing resin-based composites. Dent Mater 2024; 40:1041-1046. [PMID: 38763819 DOI: 10.1016/j.dental.2024.05.016] [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: 05/06/2024] [Accepted: 05/13/2024] [Indexed: 05/21/2024]
Abstract
OBJECTIVE To evaluate the influence of the barium glass (BG) filler in 3D printing resin-based composites for restorative structures. METHODS Experimental 3D printing resin-based composites were formulated with UDMA 70%wt, Bis-EMA 20%wt, and TEGDMA 10%wt. Photoinitiators TPO and DFI (2%wt) were used. BG was incorporated at 40%wt and 50%wt. 0%wt BG was used as negative control and the VarseoSmile Crownplus (Bego) was used as a commercial control. Specimens were printed using a 3D printer. Subsequently, specimens were washed and submitted to post-curing with 405 nm at 60ºC for 2 × 20 min at FormCure (FormLabs). 3D printing resin-based composites were evaluated by flexural strength, degree of conversion, softening in solvent, radiopacity, and cytotoxicity against gingival fibroblasts. Data were statistically analyzed using one-way ANOVA (α = 0.05). RESULTS No significant differences in flexural strength were showed between BG40% (90.5 ± 5,4 MPa), BG50% (102.0 ± 11.7 MPa) and VA (105.2 ± 11.7 MPa). Addition of 40% and 50% of BG showed no influence in the degree of conversion compared to VA (p > 0.05). All groups showed softening in solvent after immersion in ethanol (p < 0.05). All groups showed more than 1mmAl of radiopacity. BG50% showed significantly higher radiopacity (2.8 ± 0.3 mmAl) than other groups (p < 0,05). Cytotoxicity evaluation showed gingival cell viability higher than 80% for all groups. SIGNIFICANCE Addition of up to 50%wt of barium glass in experimental 3D printing resin-based composites showed promising results for long-term restorative structures.
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Affiliation(s)
- Ana Cristina Andrioli Zattera
- Graduate student, Department of Dental Materials, School of Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Francisco Amaro Morganti
- Graduate student, Department of Dental Materials, School of Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Gabriela de Souza Balbinot
- Adjunct Professor, Department of Dental Materials, School of Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Alvaro Della Bona
- Senior professor and Chair, School of Dentistry, University of Passo Fundo, Passo Fundo, RS, Brazil
| | - Fabricio Mezzomo Collares
- Associate professor and Chair, Department of Dental Materials, School of Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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Strazzi-Sahyon HB, Hadis MA, Dos Santos PH, Palin WM. The effect of photoinitiator type and filler load on physicochemical and mechanical properties of experimental light-cured resin cements through lithium disilicate ceramics of different shades and thicknesses. Dent Mater 2024:S0109-5641(24)00178-7. [PMID: 38945741 DOI: 10.1016/j.dental.2024.06.020] [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: 09/23/2023] [Revised: 06/13/2024] [Accepted: 06/14/2024] [Indexed: 07/02/2024]
Abstract
OBJECTIVE This study investigated the influence of photoinitiator types on degree of conversion (DC), rate of polymerization (RP), flexural strength (FS), flexural modulus (FM), and light transmittance (LT) of filled and unfilled light-curable resin cements through different thicknesses and shades of lithium disilicate ceramics. METHODS Lithium disilicate ceramic discs (IPS Emax Press, background [0.0], 0.5, 1.0, 2.0, 3.0, and 4.0 mm, shades A1 and BL3) were prepared. Experimental resin-based cements [TEGDMA/BisGMA (50/50 mass%)] were prepared using either camphorquinone (CQ)/amine (0.44/1.85 mol%) or TPO (0.44 mol%)], and a micro and nanofiller loads of nil (unfilled); 40/10 mass%; and 50/10 mass%). Resin cements (0.2 mm thick) were placed on the lower surface of the ceramic specimens and light-activated for 30 s from the upper surface using a Bluephase Style curing light (exitance at tip: 1236 mW/cm2 ± 1.20). LT and distribution of irradiance through the ceramics were measured using a UV-vis spectrometer and a beam profile camera, respectively (n = 3). The DC and RP were measured in real-time using mid infrared spectroscopy in attenuated total reflectance (ATR) mode (n = 3). FS and FM were measured using a universal testing machine (n = 5). Statistical analyses were performed on LT, DC, RP, FS, and FM data using a general linear model, and supplementary ANOVA and post hoc Tukey multiple comparison test were also performed (α = .05). RESULTS Thicknesses, shades, photoinitiator type, and fillers load significantly influenced the optical and mechanical characteristics of the resin-based materials (p < 0.05). The BL3 shade ceramic provided higher values of DC, RP, FS, FM, and LT compared with the A1 shade (p < 0.05). Increasing ceramic thickness decreased the properties of the resin-based materials (p < 0.05). Generally, TPO improved mechanical properties of the resin cement compared with CQ (p < 0.05). SIGNIFICANCE The luting process of indirect restorations may be improved by using high molar absorptivity, more reactive, and more efficient photoinitiators such as TPO, as opposed to conventional CQ. The use of such initiator may allow the placement of thicker and more opaque indirect restorations.
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Affiliation(s)
- Henrico Badaoui Strazzi-Sahyon
- Department of Dental Materials and Prosthodontics, Araçatuba School of Dentistry, São Paulo State University - UNESP, Araçatuba, SP, Brazil; Department of Prosthodontics and Periodontology, Bauru School of Dentistry, University of São Paulo, USP, Bauru, SP, Brazil; Biomaterials Unit, School of Dentistry, College of Medical and Dental Sciences, University of Birmingham, Birmingham B4 6NN, UK.
| | - Mohammed A Hadis
- Biomaterials Unit, School of Dentistry, College of Medical and Dental Sciences, University of Birmingham, Birmingham B4 6NN, UK
| | - Paulo Henrique Dos Santos
- Department of Dental Materials and Prosthodontics, Araçatuba School of Dentistry, São Paulo State University - UNESP, Araçatuba, SP, Brazil; Dental Research Institute - Restorative Dentistry, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - William M Palin
- Biomaterials Unit, School of Dentistry, College of Medical and Dental Sciences, University of Birmingham, Birmingham B4 6NN, UK
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Sampaio CS, Abreu JLBD, Kornfeld B, Silva EMD, Giannini M, Hirata R. Short curing time bulk fill composite systems: volumetric shrinkage, degree of conversion and Vickers hardness. Braz Oral Res 2024; 38:e030. [PMID: 38597548 DOI: 10.1590/1807-3107bor-2024.vol38.0030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 12/18/2021] [Indexed: 04/11/2024] Open
Abstract
This study aimed to evaluate volumetric polymerization shrinkage, degree of conversion and Vickers hardness of four bulk-fill resin composites light-activated with their dedicated light curing units (LCUs). Four groups were evaluated, according to the type of composite and curing mode: Tetric EvoCeram Bulk-fill (TEBO) and Tetric EvoFlow Bulk-fill (TEBF) were light-activated with Bluephase Style 20i (20s, in high-mode), while Tetric Powerfill (TEPO) and Tetric Powerflow (TEPF) were light-activated with Bluephase PowerCure (3s). Volumetric polymerization shrinkage test (n = 6) was performed in standardized box-shaped class-I cavities of extracted third molars (4 x 4 x 4 mm). Teeth were scanned before and after resin composite application by micro-computed tomography, and acquired data were evaluated with Amira software. Degree of conversion (n = 5) was evaluated at the top and bottom surfaces of composite cylindric samples (4 mm diameter, 4 mm thickness) using an FT-IR spectrometer (spectra between 1,500 and 1,800 cm-1, 40 scans at a resolution of 4 cm-1). Three Vickers indentations (50 g / 15 s), spaced 500 μm apart, were performed on the top and bottom composite surfaces and averaged. One-way ANOVA was used for data evaluation. TEPF showed the lowest volumetric polymerization shrinkage (p < 0.05), while the other composites were not significantly different within each other (p > 0.05). All materials presented a significant decrease in degree of conversion and Vickers hardness when compared top to bottom surfaces (p < 0.05). Bottom to top surface ratios for degree of conversion ranged from 0.8 (TEBO and TEPO) to 0.9 (TEBF and TEPF), and from 0.4 (TEPO) to 0.7 (TEBF and TEPF) for hardness. In conclusion, resinous materials present a decrease in hardness and degree of conversion from top to bottom even when a higher power is used, while the flowable material TEPF showed the lowest volumetric shrinkage values compared to the other materials.
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Affiliation(s)
- Camila Sobral Sampaio
- New York University, College of Dentistry, Advanced Clinical Fellowship in Aesthetics, Operative and Digital Dentistry, New York, NY, USA
| | - João Luiz Bittencourt de Abreu
- Universidade Federal Fluminense - UFF, School of Dentistry, Analytical Laboratory of Restorative Biomaterials - LABiom-R, Niteroi, RJ, Brazil
| | - Batsheva Kornfeld
- New York University, College of Dentistry, Department of Biomaterials and Biomimetics, New York, NY, USA
| | - Eduardo Moreira da Silva
- Universidade Federal Fluminense - UFF, School of Dentistry, Analytical Laboratory of Restorative Biomaterials - LABiom-R, Niteroi, RJ, Brazil
| | - Marcelo Giannini
- Universidade Estadual de Campinas - Unicamp, Piracicaba Dental School, Department of Restorative Dentistry, Piracicaba, SP, Brazil
| | - Ronaldo Hirata
- New York University, College of Dentistry, Department of Biomaterials and Biomimetics, New York, NY, USA
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Hadis MA, Shortall AC, Palin WM. The power of light - From dental materials processing to diagnostics and therapeutics. Biomater Investig Dent 2024; 11:40308. [PMID: 38645925 PMCID: PMC11022655 DOI: 10.2340/biid.v11.40308] [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: 11/29/2023] [Accepted: 02/12/2024] [Indexed: 04/23/2024] Open
Abstract
Harnessing the power of light and its photonic energy is a powerful tool in biomedical applications. Its use ranges from biomaterials processing and fabrication of polymers to diagnostics and therapeutics. Dental light curable materials have evolved over several decades and now offer very fast (≤ 10 s) and reliable polymerization through depth (4-6 mm thick). This has been achieved by developments on two fronts: (1) chemistries with more efficient light absorption characteristics (camphorquinone [CQ], ~30 L mol-1 cm1 [ʎmax 470 nm]; monoacylphosphine oxides [MAPO], ~800 L mol-1 cm-1 [ʎmax 385 nm]; bisacylphosphine oxide [BAPO], ~1,000 L mol-1 cm-1 [ʎmax 385 nm]) as well mechanistically efficient and prolonged radical generation processes during and after light irradiation, and; (2) introducing light curing technologies (light emitting diodes [LEDs] and less common lasers) with higher powers (≤ 2 W), better spectral range using multiple diodes (short: 390-405 nm; intermediate: 410-450 nm; and long: 450-480 nm), and better spatial power distribution (i.e. homogenous irradiance). However, adequate cure of materials falls short for several reasons, including improper selection of materials and lights, limitations in the chemistry of the materials, and limitations in delivering light through depth. Photonic energy has further applications in dentistry which include transillumination for diagnostics, and therapeutic applications that include photodynamic therapy, photobiomodulation, and photodisinfection. Light interactions with materials and biological tissues are complex and it is important to understand the advantages and limitations of these interactions for successful treatment outcomes. This article highlights the advent of photonic technologies in dentistry, its applications, the advantages and limitations, and possible future developments.
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Affiliation(s)
- Mohammed A Hadis
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Adrian C Shortall
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - William M Palin
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
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Farah RI, Alblihed IA, Aljuoie AA, Alresheedi B. Light Polymerization through Glass-ceramics: Influence of Light-polymerizing Unit's Emitted Power and Restoration Parameters (Shade, Translucency, and Thickness) on Transmitted Radiant Power. Contemp Clin Dent 2024; 15:35-43. [PMID: 38707663 PMCID: PMC11068246 DOI: 10.4103/ccd.ccd_124_23] [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: 03/15/2023] [Revised: 01/30/2024] [Accepted: 02/08/2024] [Indexed: 05/07/2024] Open
Abstract
Background This in vitro study assessed light transmission through ceramic discs varying in shade, translucency, and thickness using light-polymerizing units with different radiant power/flux (RP) outputs. Methods Disc-shaped specimens (0.5 mm, 1.0 mm, and 2.0 mm) were made from high and low-translucency glass-ceramic ingots (IPS e.max Press) in shades A1 and A4, totaling 60 discs. Two light-polymerizing units with different power outputs were used, and their emission spectra were verified. The transmitted RP values for each ceramic specimen were measured and irradiance and radiant energy influx were calculated. Differences between the light-polymerizing units and the influence of the three ceramic parameters were evaluated using an independent-samples t-test and three-way analysis of variance (ANOVA) tests (α = 0.05). Results A statistically significant difference was observed in the mean transmitted RP values between the two light-polymerizing units. Furthermore, the three-way ANOVA test showed a significant effect of shade, translucency, and thickness, as well as a significant interaction between each pair of variables and all three variables on the transmitted RP (P < 0.05). Conclusions Despite the significant attenuation in the transmitted RP, especially in ceramics with higher shade chromaticity and thickness and lower translucency, the calculated minimal irradiance values for both light-polymerizing units (their emitted power ≥ 500 mW) were greater than the minimum recommended irradiance threshold (100 mW/cm2). However, the exposure duration needs to be increased to provide the resin with sufficient radiant exposure for adequate polymerization.
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Affiliation(s)
- Ra’fat I. Farah
- Department of Prosthetic Dental Sciences, College of Dentistry, Qassim University, Al-Mulaydah, Qassim, Saudi Arabia
| | - Ibrahim A. Alblihed
- Medical City, College of Dentistry, Qassim University, Al-Mulaydah, Qassim, Saudi Arabia
| | - Alhareth A. Aljuoie
- Medical City, College of Dentistry, Qassim University, Al-Mulaydah, Qassim, Saudi Arabia
| | - Bandar Alresheedi
- Department of Prosthetic Dental Sciences, College of Dentistry, Qassim University, Al-Mulaydah, Qassim, Saudi Arabia
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Cavalcanti KGBA, Pulido C, Moreira PHA, Monteles CF, Salvatierra BLC, Siqueira FSF, Soares CJ, Reis A, Loguercio AD, Cardenas AFM. Effect of irradiance and exposure time on the adhesive properties of universal adhesives after 2 years of storage. Clin Oral Investig 2023; 27:5223-5232. [PMID: 37458867 DOI: 10.1007/s00784-023-05142-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 07/04/2023] [Indexed: 09/10/2023]
Abstract
OBJECTIVE This study aims to evaluate the effects of exposure time and irradiance on the dentin bonding properties (microtensile bond strength (μTBS) and nanoleakage (NL)) of the Clearfil Universal Bond Quick (CUQ) adhesive and Scotchbond Universal Adhesive (SBU) immediately and after 2 years of water storage. MATERIAL AND METHODS Hence, 128 human molars were randomly assigned to 16 groups based on adhesive strategy, irradiance/exposure times, and storage time for each universal adhesive tested. The adhesives were applied using the etch-and-rinse and self-etch strategies and were light-cured using four different irradiance/exposure times: 1400 mW/cm2 for 5 s (1400 × 5), 1400 mW/cm2 for 10 s (1400 × 10), 3200 mW/cm2 for 5 s (3200 × 5), and 3200 mW/cm2 for 10 s (3200 × 10). Then, each sample was restored and sectioned into a resin-dentin bonded stick to be tested for μTBS and NL (immediately and after 2 years of water storage). The mean μTBS and NL of all resin-dentin bonded sticks from the same hemi-tooth (factor time) were statistically analyzed using a three-way ANOVA and Tukey's test (a = 0.05). RESULTS Despite a significant decrease in the μTBS values for all groups after 2 years of water storage, the 3200 × 5 group showed higher μTBS values, whereas the 3200 × 10 group showed lower μTBS values for both universal adhesives tested. Although a significant increase in the NL values was observed for all groups after 2 years of water storage, the 3200 × 10 group showed higher NL values than the other groups (p < 0.001). CONCLUSION Results indicate that light-curing the adhesive layer with 14-16 J/cm2 led to an improvement in the stability of the resin-dentin adhesive interface. A longer exposure time (10 s) coupled with a higher irradiance (3200 mW/cm2) resulted in a greater degree of degradation of the adhesive interface. CLINICAL SIGNIFICANCE To guarantee better stability of the adhesive interface, clinicians could be preferred a light-cured universal adhesive layer with 14-16 J/cm2. Higher irradiances should be avoided.
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Affiliation(s)
| | - Camilo Pulido
- Department of Restorative Dentistry and Biomaterials, San Francisco de Quito University, Quito, Ecuador
| | - Pedro H A Moreira
- Postgraduate Program in Dentistry, CEUMA University, São Luis, MA, Brazil
| | - Camila F Monteles
- Postgraduate Program in Dentistry, CEUMA University, São Luis, MA, Brazil
| | - Byron L C Salvatierra
- Department of Restorative Dentistry, Ponta Grossa State University, Rua Carlos Cavalcanti, 4748, Bloco M, Sala 64A-Uvaranas, Ponta Grossa, Paraná, 84030-900, Brazil
| | | | - Carlos J Soares
- Postgraduate Program in Dentistry, CEUMA University, São Luis, MA, Brazil
- Department of Operative Dentistry and Dental Materials, Dental School, Federal University of Uberlândia, Uberlândia, MG, Brazil
| | - Alessandra Reis
- Department of Restorative Dentistry, Ponta Grossa State University, Rua Carlos Cavalcanti, 4748, Bloco M, Sala 64A-Uvaranas, Ponta Grossa, Paraná, 84030-900, Brazil
| | - Alessandro D Loguercio
- Department of Restorative Dentistry, Ponta Grossa State University, Rua Carlos Cavalcanti, 4748, Bloco M, Sala 64A-Uvaranas, Ponta Grossa, Paraná, 84030-900, Brazil.
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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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Lempel E, Szebeni D, Őri Z, Kiss T, Szalma J, Lovász BV, Kunsági-Máté S, Böddi K. The effect of high-irradiance rapid polymerization on degree of conversion, monomer elution, polymerization shrinkage and porosity of bulk-fill resin composites. Dent Mater 2023; 39:442-453. [PMID: 36918332 DOI: 10.1016/j.dental.2023.03.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 02/17/2023] [Accepted: 03/03/2023] [Indexed: 03/13/2023]
Abstract
OBJECTIVE The purpose was to compare the degree of conversion (DC), monomer elution (ME), polymerization shrinkage (PS) and porosity of two addition-fragmentation chain transfer (AFCT) modified resin-based composites (RBC) light-cured with rapid- (RP), turbo- (TP) or conventional polymerization (CP) settings. METHODS Cylindrical samples (6-mm wide, 4-mm thick) were prepared from Tetric PowerFill (TPF) and Filtek One Bulk (FOB). Four groups were established according to the polymerization settings: 3s-RP, 5s-TP, 10s-CP and 20s-CP. Samples in 1 mm thickness with 20s-CP settings served as controls. The DC at the top and bottom surfaces was measured with micro-Raman spectroscopy. ME was detected with high-performance liquid chromatography. PS and porosity were analyzed by micro-computed tomography. ANOVA and Tukey's post-hoc test, multivariate analysis and partial eta-squared statistics were used to analyze the data (p < 0.05). RESULTS FOB showed higher DC values (61.5-77.5 %) at the top compared to TPF (43.5-67.8 %). At the bottom TPF samples achieved higher DCs (39.9-58.5 %) than FOB (18.21-66.18 %). Extending the curing time increased DC (except the top of FOB) and decreased ME. BisGMA release was the highest among the detected monomers from both RBCs. The amount was three-fold more from TPF. The factor Material and Exposure significantly influenced DC and ME. PS (1.8-2.5 %) did not differ among the groups and RBCs except for the lowest value of TPF cured with the 3s_RP setting (p = 0.03). FOB showed 4.5-fold lower porosity (p < 0.001). Significantly higher pore volume was detected after polymerization in 3s_RP (p < 0.001). SIGNIFICANCE High-irradiance rapid 3-s curing of AFCT modified RBCs resulted in inferior results for some important material properties. A longer exposure time is recommended in a clinical situation.
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Affiliation(s)
- Edina Lempel
- Department of Restorative Dentistry and Periodontology, University of Pécs Medical School, Tüzér Street 1, Pécs 7623, Hungary.
| | - Donát Szebeni
- Department of Restorative Dentistry and Periodontology, University of Pécs Medical School, Tüzér Street 1, Pécs 7623, Hungary
| | - Zsuzsanna Őri
- János Szentágothai Research Center, Ifjúság Street 12, Pécs 7624, Hungary; Department of General and Physical Chemistry, University of Pécs, Ifjúság Street 6, Pécs 7624, Hungary
| | - Tamás Kiss
- János Szentágothai Research Center, Ifjúság Street 12, Pécs 7624, Hungary
| | - József Szalma
- Department of Oral and Maxillofacial Surgery, University of Pécs Medical School, Tüzér Street 1, Pécs 7623, Hungary
| | - Bálint Viktor Lovász
- Department of Oral and Maxillofacial Surgery, University of Pécs Medical School, Tüzér Street 1, Pécs 7623, Hungary
| | - Sándor Kunsági-Máté
- János Szentágothai Research Center, Ifjúság Street 12, Pécs 7624, Hungary; Department of Organic and Medicinal Chemistry, University of Pécs, Faculty of Pharmacy, Honvéd Street 1, Pécs 7624, Hungary
| | - Katalin Böddi
- Department of Biochemistry and Medical Chemistry, University of Pécs Medical School, Szigeti Street 12, Pécs 7624, Hungary
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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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Hirata R, Sampaio CS, Atria PJ, Giannini M, Coelho PG, Yamaguchi S. Effect of High-radiant Emittance and Short Curing Time on Polymerization Shrinkage Vectors of Bulk Fill Composites. Oper Dent 2023; 48:51-58. [PMID: 36534034 DOI: 10.2341/20-167-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2022] [Indexed: 12/23/2022]
Abstract
PURPOSE To evaluate the effect of short curing time using a high-radiant emittance light on polymerization shrinkage vectors in different consistency bulk-fill composites (BFRCs) using micro-computed tomography. METHODS AND MATERIALS Radiopaque zirconia fillers were homogeneously incorporated and functioned as radiopaque tracers into two regular-paste: TBFill (Tetric EvoCeram Bulk Fill) and TPFill (Tetric PowerFill), and two flowable (n=6): TBFlow (Tetric EvoFlow Bulk Fill) and TPFlow (Tetric PowerFlow) resin composites. Class I cavities (4 mm depth × 4 mm length × 4 mm width) were 3D-printed and filled in a single increment: TBFill and TBFlow were light-activated using a Bluephase Style 20i (10 seconds in high-mode); TPFill and TPFlow were light-activated using a Bluephase PowerCure (three seconds). The same adhesive system (Adhese Universal) was used for all groups. Microcomputed tomography scans were obtained before and after light-activation. Filler particle movement was identified by polymerization shrinkage vectors at five depths (from 0-4 mm): top, top-middle, middle, middle-bottom and bottom. RESULTS TPFlow showed the lowest total vector displacement, followed by TBFlow, TBFill and TPFill, significantly different among each other (p<0.05). Generally, BFRCs showed decreased vector displacement with increased depth, and higher displacement at the top-surface (p<0.05). Qualitative analysis showed a similar pattern of vector magnitude and displacement for groups TBFill and TPFill, with displacement vectors on occlusal (top) surfaces toward the center of the restoration from the top to middle areas, and relatively limited displacement at the bottom. TBFlow and TPFlow showed more displacement on the occlusal (top). CONCLUSIONS Short curing time with high-radiant emittance on fast-curing BFRCs was shown to be a feasible option in terms of vector displacement. Flowable BFRCs presented lower vector displacement than their regular-viscosity versions.
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Affiliation(s)
- R Hirata
- Ronaldo Hirata, DDS, MS, PhD, Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, NY USA
| | - C S Sampaio
- *Camila S Sampaio, DDS, MD, PhD, Department of Biomaterials, School of Dentistry, Universidad de los Andes, Santiago, Chile
| | - P J Atria
- Pablo J Atria, DDS, MS, Department of Biomaterials, School of Dentistry, Universidad de los Andes, Santiago, Chile
| | - M Giannini
- Marcelo Giannini, DDS, MS, PhD, Department of Restorative Dentistry, Operative Dentistry Division, University of Campinas, Piracicaba Dental School, Piracicaba, Brazil
| | - P G Coelho
- Paulo G. Coelho, DDS, MS, PhD, Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, NY
| | - S Yamaguchi
- Satoshi Yamaguchi, DDS, MS, PhD, Department of Biomaterials Science, Osaka University Graduate School of Dentistry, Osaka, Japan
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11
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Cardenas A, Siqueira F, Nuñez A, Nonato RF, Cavalcanti K, Soares CJ, Reis A, Loguercio AD. Influence of Irradiance and Exposure Times on the Mechanical and Adhesive Properties of Universal Adhesives with Dentin. Oper Dent 2022; 47:412-424. [PMID: 35917253 DOI: 10.2341/21-042-l] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2021] [Indexed: 11/23/2022]
Abstract
OBJECTIVES This study evaluated the influence of irradiance/exposure time on the Knoop hardness (KHN) and polymer cross-linking density (PCLD), as well as microtensile bond strength (μTBS), nanoleakage (NL), and in situ degree of conversion (DC) of universal adhesives. METHODS AND MATERIALS Two universal adhesive systems, Clearfil Universal Bond Quick (CUQ) and Scotchbond Universal Adhesive (SBU), were light-cured using various irradiance/exposure times: 1400 mW/cm2 for 5 s (1400*5); 1400 mW/cm2 for 10 s (1400*10); 3200 mW/cm2 for 5 s (3200*5); and 3200 mW/cm2 for 10 s (3200*10). Adhesive disks from each group were used to measure PCLD by KHN. One hundred and twenty-eight human molars were randomly assigned to 16 groups according to the following variables: adhesive system vs adhesive strategies vs radiance/exposure times. After restoration, specimens were sectioned into resin-dentin sticks and tested for μTBS, NL, and DC. The data from PCLD (%), KHN, μTBS (MPa), NL (%), and DC (%) data were subjected to ANOVA and Tukey's test (α=0.05). RESULTS Significant reductions in KHN, μTBS, and DC (p=0.00001) values and an increase in NL and PCLD (p=0.00001) values were observed for 3200*10 when compared with other groups. Higher KHN, μTBS, and DC (p=0.000001) values were observed for 3200*5 in comparison with the other groups. The 1400*5 (7 J/cm2) and 1400*10 (14 J/cm2) groups showed intermediate values (p=0.000001). CONCLUSION Although similar results in terms of hardness, polymer cross-linking density and nanoleakage were observed when 5 seconds at 3200 mW/cm2 and 10 seconds at 1400 mW/cm2 groups were compared, the use of higher irradiance (3200 mW/cm2) for only 5 seconds showed better results in terms of bond strength and degree of conversion for both universal adhesives to dentin. The prolonged exposure time (10 seconds) at the higher irradiance (3200 mW/cm2) showed the worst results.
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Affiliation(s)
- Afm Cardenas
- Andres Felipe Millan Cardenas, DDS, Ms, PhD, professor, Postgraduate Program in Dentistry, CEUMA University, São Luis, MA, Brazil
| | - Fsf Siqueira
- Fabiana Suelen Figuerêdo de Siqueira, DDS, Ms, PhD, professor, Postgraduate Program in Dentistry, CEUMA University, São Luis, MA, Brazil
| | - A Nuñez
- Alejandra Nuñez, DDS, Ms, PhD student, Department of Restorative Dentistry, Ponta Grossa State University, Ponta Grossa, Paraná, Brazil, and Professor, Department of Restorative Dentistry and Biomaterials, San Francisco de Quito University, Quito, Ecuador
| | - R F Nonato
- Rammon de Faria Nonato, DDS, Ms student, Postgraduate Program in Dentistry, CEUMA University, São Luis, MA, Brazil
| | - Kgba Cavalcanti
- Karoline Guará Brusaca Almeida Cavalcanti, DDS, Ms, PhD student, Postgraduate Program in Dentistry, CEUMA University, São Luis, MA, Brazil
| | - C J Soares
- Carlos José Soares, DDS, Ms, PhD, professor, Departament of Postgraduate Program in Dentistry, CEUMA University, São Luis, MA, Brazil, and Dental School, Department of Operative Dentistry and Dental Materials, Federal University of Uberlândia, Uberlândia, MG, Brazil
| | - A Reis
- *Alessandra Reis, DDS, PhD, professor, Department of Restorative Dentistry, Ponta Grossa State University, Ponta Grossa, PR, Brazil
| | - A D Loguercio
- Alessandro D. Loguercio, DDS, Ms, PhD, professor, Department of Restorative Dentistry, Ponta Grossa State University, Ponta Grossa, PR, Brazil
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12
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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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13
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German MJ. Developments in resin-based composites. Br Dent J 2022; 232:638-643. [PMID: 35562465 PMCID: PMC9106574 DOI: 10.1038/s41415-022-4240-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/21/2022] [Indexed: 11/10/2022]
Abstract
With the phasing down of dental amalgam use in response to the Minamata Convention, it is likely that resin-based composite restoratives will be the dental material of choice for the direct restoration of compromised dentition in the UK, at least for the foreseeable future. The current materials have a finite lifespan, with failures predominately due to either secondary caries or fracture. Consequently, there is considerable in vitro research reported each year with the intention of producing improved materials. This review describes the recent research in materials designed to have low polymerisation shrinkage and increased mechanical properties. Also described is research into materials that are either antimicrobial or are designed to release ions into the surrounding oral environment, with the aim of stimulating remineralisation of the surrounding dental tissues. It is hoped that by describing this recent research, clinicians will be able to gain some understanding of the current research that will potentially lead to new products that they can use to improve patient treatment in the future. Provides an overview of recent research developments aimed at improving the performance of resin-based composites. Details the recent developments in monomers and fillers to produce resin-based composites that either have lower polymerisation shrinkage or better mechanical properties compared to current commercially available products. Describes recent research on developing resin-based composites that can act as potential sources of antimicrobial or remineralising agents.
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Affiliation(s)
- Matthew J German
- School of Dental Sciences, Translational and Clinical Research Institute, Newcastle University, Framlington Place, Newcastle upon Tyne, UK.
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Depth of cure of 10 resin-based composites light-activated using a laser diode, multi-peak, and single-peak light-emitting diode curing lights. J Dent 2022; 122:104141. [PMID: 35483497 DOI: 10.1016/j.jdent.2022.104141] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/19/2022] [Accepted: 04/21/2022] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVES To evaluate the depth of cure (DOC) of ten contemporary resin-based composites (RBCs), light-cured using different LCUs and exposure times. METHODS The power, radiant emittance, irradiance, radiant exposure (RE), and beam profiles from a laser (M, Monet), a multi-peak (V, Valo Grand), and single-peak (S, SmartLite Pro) LCU were measured. The DOC was measured using a 6-mm diameter metal mold and a solvent dissolution method to remove the uncured RBC. The length of the remaining RBC was divided by 2. The exposure times were: 1s and 3s for M, 10s and 20s for V, and 10s and 20s for S. Data were analyzed using: Bland-Altman distribution, Pearson's Correlation, and an artificial neural network (ANN) to establish the relative importance of the factors on the DOC (α=0.05; β=0.2). RESULTS Significant differences were found in the DOC of the different LCUs and composites. The laser LCU emitted the highest power, radiant emittance, and irradiance. However, this LCU used for 1 s delivered the lowest RE and produced the shortest DOC in all ten RBCs. The ANN demonstrated that the RE is the most critical factor for the DOC. Bland-Altman comparisons showed that the DOCs achieved with the laser LCU used for 1s were between 17 - 34 % shorter than the other conditions. CONCLUSIONS Although the laser LCU cured all 10 RBCs when used for 1s, it produced the shallowest DOC, and some RBCs did not achieve the minimum DOC threshold. The RE and not the irradiance was the most important factor in determining the DOC of RBCs. CLINICAL SIGNIFICANCE Despite delivering high power and irradiance, the laser used for l s delivered a lower radiant exposure than the conventional LCUs used for 10 s. This resulted in a shorter DOC.
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15
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Sullivan B, Kalliecharan D, Kostylev I, Earle G, Stansbury JW, Price RB, Labrie D. Photo-polymerization kinetics of a dental resin at a high temporal resolution. J Mech Behav Biomed Mater 2021; 124:104884. [PMID: 34638087 DOI: 10.1016/j.jmbbm.2021.104884] [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: 07/07/2021] [Revised: 09/28/2021] [Accepted: 10/04/2021] [Indexed: 10/20/2022]
Abstract
OBJECTIVES This study: 1) aims to measure with high temporal resolution the intrinsic rate of the degree of conversion (DC) of a dental resin-based composite (RBC) photo-cured at two irradiances; 2) aims to determine the transition time at which the DC rate is maximum; 3) used two different irradiances to measure the shift in transition time; 4) aims to compare transition times measured using DC and shrinkage strain. METHODS Samples (n = 20) 1 mm thick by 10 mm diameter of Filtek One bulk-fill restorative A2 shade (3M Oral Care) were photocured for 20 s with a single emission peak (wavelength centered at 455 nm) light-emitting-diode-based light-curing unit at irradiance levels of 890 mW/cm2 and 209 mW/cm2, and initial sample temperature of T = 23 °C. The DC was measured in real-time using Attenuated Total Reflection (ATR) FTIR spectroscopy with a sampling rate of 13 DC data points per second. The data were analyzed within a phenomenological autocatalytic model. In addition, the axial shrinkage strain was measured using 3 samples of the RBC with the same outer dimensions and under similar experimental conditions using the bonded disk method and an interferometric technique. RESULTS For the 890 mW/cm2 and 209 mW/cm2 irradiance levels, the DC with time was found to agree with the model enabling the determination of transition times of 0.66 ± 0.05 s and 2.3 ± 0.2 s, and the DC at these times of 5.5 ± 0.2% and 6.4 ± 0.2%. The maximum linear strain rate at 0.76 ± 0.01 s and 1.98 ± 0.02 s for the 890 mW/cm2 and 209 mW/cm2 irradiance levels, respectively, are within two standard deviations of the corresponding transition times. SIGNIFICANCE At an irradiance level much greater than 1000 mW/cm2, the photo-polymerization kinetics of a dental RBC may be too fast to be measured accurately using ATR-FTIR spectroscopy. A viable alternative to monitor the kinetics is through the measurements of the axial shrinkage strain employing the bonded disk method and an interferometric technique.
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Affiliation(s)
- Braden Sullivan
- Department of Dental Clinical Sciences, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - David Kalliecharan
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Ivan Kostylev
- Quantum Dynamics Unit, Okinawa Institute of Science and Technology, Tancha 1919-1, Okinawa, 904-0495, Japan
| | - Guy Earle
- IObIO Inc., 1676 Edward Street, Halifax, Nova Scotia, B3H 3J3, Canada
| | - Jeffrey W Stansbury
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, United States; Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80309-0596, United States
| | - Richard B Price
- Department of Dental Clinical Sciences, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Daniel Labrie
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.
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16
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Lima AF. Transmission of violet and blue light and current light units through glass-reinforced ceramics with different thicknesses. J Prosthodont Res 2021; 65:387-392. [PMID: 33041276 DOI: 10.2186/jpr.jpor_2019_405] [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] [Indexed: 11/06/2022]
Abstract
Purpose To evaluate the effect of glass-reinforced ceramics (leucite and lithium disilicate) with different thicknesses (1, 2, and 3 mm) on the wavelength and irradiance spectrum of blue and violet lights. In addition, the effect of the ceramics on four current light-curing units (LCUs) was evaluated: a halogen lamp, a single peak LED, and two multi-peak LEDs.Methods Ceramic discs of different thicknesses (1, 2, and 3 mm) were obtained from computer-aided design and computer-aided manufacturing (CAD-CAM) blocks. The irradiance, radiant exposure, and emission spectrum of the four LCUs were analyzed using a spectrometer-based instrument. To evaluate the violet and blue lights, a specific device that provides a narrow emission spectrum was used.Results The ceramics reduced the irradiance of all the tested LCUs. However, the wavelength of the transmitted light was only altered slightly. The effect of leucite and lithium disilicate varied according to the type of LCU and thickness of the ceramic disc evaluated .Conclusions From the results, it could be concluded that the thickness of the leucite and lithium disilicate ceramic significantly reduced the irradiance of the light emitted by the LCUs, with minimal changes on the wavelength spectrum of the lights. The effects of the ceramic on irradiance and transmitted wavelengths of the blue and violet lights was slightly different.
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Affiliation(s)
- Adriano F Lima
- Dental Research Division, Paulista University, Sao Paulo, Brazil
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17
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Palialol AR, Martins CP, Dressano D, Aguiar FHB, Gonçalves LS, Marchi GM, Pfeifer CS, Lima AF. Improvement on properties of experimental resin cements containing an iodonium salt cured under challenging polymerization conditions. Dent Mater 2021; 37:1569-1575. [PMID: 34407920 DOI: 10.1016/j.dental.2021.08.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 08/04/2021] [Indexed: 11/19/2022]
Abstract
OBJECTIVE The use of resin cements in clinical practice entails photopolymerization through prosthetic devices, which precludes light penetration. The objective of this study was to modify experimental resin cements (ERCs) with diphenyliodonium hexafluorophosphate (DPI) in an attempt to improve chemical and mechanical properties of materials cured with reduced irradiance and final radiant exposure. METHODS A co-monomer base containing a 1:1 mass ratio of 2.2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane (bis-GMA) and triethyleneglycol dimethacrylate (TEGDMA) was prepared, with 1mol% of camphorquinone and 2mol% of ethyl 4-(dimethylamino)benzoate as initiator system. The resin was divided into 4 fractions according to the DPI concentrations (0, 0.5, 1 and 2mol%). The challenging polymerization condition was simulated performing the light activation (12, 23 and 46s) through a ceramic block (3mm thick). The irradiance was assessed with a calibrated spectrometer (1320mW/cm2), resulting in three levels of radiant exposure (0.58, 1.1 and 2.2J/cm2). The polymerization kinetics was evaluated in real-time using a spectrometer (Near-IR). Water sorption and solubility was analyzed and the cohesive strength of resins obtained through the microtensile test. Polymerization stress was assessed by Bioman method. RESULTS Resins containing DPI had higher degree of conversion and rate of polymerization than the control (without DPI). The use of DPI reduced water sorption and solubility, and led to higher cohesive strength compared to resins without the iodonium salt. However, the stress of polymerization was higher for experimental resins with DPI. SIGNIFICANCE Even under remarkably reduced irradiance, cements containing a ternary initiating system with an iodonium salt can present an optimal degree of conversion and chemical/mechanical properties.
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Affiliation(s)
- Alan R Palialol
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av. Limeira, 901 Mail Box 52, Piracicaba, SP 13414-903, Brazil.
| | - Caetano P Martins
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av. Limeira, 901 Mail Box 52, Piracicaba, SP 13414-903, Brazil.
| | - Diogo Dressano
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av. Limeira, 901 Mail Box 52, Piracicaba, SP 13414-903, Brazil.
| | - Flavio H B Aguiar
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av. Limeira, 901 Mail Box 52, Piracicaba, SP 13414-903, Brazil.
| | - Luciano S Gonçalves
- Department of Restorative Dentistry, School of Dentistry, Federal University of Santa Maria, Av. Roraima, 1000 - Camobi, Santa Maria, RS 97105-900, Brazil.
| | - Giselle M Marchi
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av. Limeira, 901 Mail Box 52, Piracicaba, SP 13414-903, Brazil.
| | - Carmem S Pfeifer
- Biomaterials and Biomechanics, Department of Restorative Dentistry, Oregon Health & Science University, Portland, OR 97239, USA.
| | - Adriano F Lima
- Dental Research Division, Paulista University, Rua Doutor Bacelar, 1212, 04026-002 SP, Brazil.
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Tichy A, Bradna P. Applicability of Exposure Reciprocity Law for Fast Polymerization of Restorative Composites Containing Various Photoinitiating Systems. Oper Dent 2021; 46:406-418. [PMID: 34478559 DOI: 10.2341/20-112-l] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2020] [Indexed: 11/23/2022]
Abstract
OBJECTIVES The exposure reciprocity law (ERL) has been used to calculate the optimal irradiation time of dental composites. This study examined the applicability of ERL for fast polymerization of restorative composites containing various photoinitiating systems using a high-power multi-peak light-emitting diode (LED) lamp. METHODS Three commercial composites differing in photoinitiating systems were tested: Filtek Ultimate Universal Restorative (FU) with a camphorquinone-amine (CQ-A) photoinitiating system, Tetric EvoCeram (TEC) with CQ-A and (2,4,6-trimethylbenzoyl)phosphine oxide (TPO), and Estelite Σ Quick (ESQ) with CQ and a radical amplified photopolymerization (RAP) initiator. Specimens 2-mm thick were polymerized using a high-power multipeak LED lamp (Valo) at 3 pairs of radiant exposures (referred to as low, moderate, and high) ranging from 15.8-26.7 J/cm2. They were achieved by different combinations of irradiation time (5-20 seconds) and irradiance (1300-2980 mW/cm2) as determined with a calibrated spectrometer. Knoop microhardness was measured 1, 24, and 168 hours after polymerization on specimen top (irradiated) and bottom surfaces to characterize the degree of polymerization. The results were statistically analyzed using a three-way analysis of variance and Tukey's post hoc tests, α = 0.05. RESULTS Microhardness increased with radiant exposure and except for ESQ, top-surface microhardness was significantly higher than that on bottom surfaces. Combinations of high irradiance and short irradiation time significantly increased the top-surface microhardness of TEC at low and moderate radiant exposures, and the bottom-surface microhardness of FU at a low radiant exposure. In contrast, the microhardness of ESQ on both surfaces at high radiant exposure increased significantly when low irradiance and long irradiation time were used. With all tested composites, bottom-surface microhardness obtained at low radiant exposure was below 80% of the maximum top-surface microhardness, indicating insufficient polymerization. CONCLUSION Combinations of irradiance and irradiation time had a significant effect on microhardness, which was affected by photoinitiators and the optical properties of composites as well as spectral characteristics of the polymerization lamp. Therefore, ERL cannot be universally applied for the calculation of optimal composite irradiation time. Despite high irradiance, fast polymerization led to insufficient bottom-surface microhardness, suggesting the necessity to also characterize the degree of polymerization on the bottom surfaces of composite increments when assessing the validity of ERL.
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Utilizing Light Cure Units: A Concise Narrative Review. Polymers (Basel) 2021; 13:polym13101596. [PMID: 34063428 PMCID: PMC8157231 DOI: 10.3390/polym13101596] [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: 04/03/2021] [Revised: 05/11/2021] [Accepted: 05/11/2021] [Indexed: 01/19/2023] Open
Abstract
The use of photo-curable resin composite restorations is an essential treatment modality in modern dental practice. The success and longevity of these restorations depend on achieving predictable and effective polymerization. Understanding the dynamics of the polymerization and the effect of light cure units (LCUs) on this process is paramount. The goal of this concise narrative review is to provide a simplified presentation of basic principles of composite chemistry, polymerization reactions, and photo-curing with relevant terminologies. Clinical guidelines for choosing and maintaining LCUs, as well as safety precautions and factors under the control of the clinician are listed. Finally, clinical recommendations of LCUs’ usage and monitoring are included to aid practitioners in achieving predictable polymerization during the placement of direct resin composite restorations.
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Rocha MG, Roulet JF, Sinhoreti MAC, Correr AB, Oliveira D. Light Transmittance and Depth of Cure of a Bulk Fill Composite Based on the Exposure Reciprocity Law. Braz Dent J 2021; 32:78-84. [PMID: 33914006 DOI: 10.1590/0103-6440202103842] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 11/30/2020] [Indexed: 11/22/2022] Open
Abstract
The objective of this study was to evaluate the effect of the exposure reciprocity law of a multi-wave light-emitting diode (LED) on the light transmittance (LT), depth of cure (DOC) and degree of conversion in-depth (DC) of a bulk fill composite. A bulk fill composite (EvoCeram® bulk fill, Ivoclar Vivadent) was photoactivated using the multi-wave LED (VALO™ Cordless, Ultradent). The LED was previously characterized using a spectrophotometer to standardize the time of exposure when using the Standard or Xtra-Power modes with the same radiant exposure of 20J/cm2. LT was evaluated through samples of the bulk fill composite every millimeter till 4 mm in-depth. DOC was evaluated according to the ISO 4049. DC of the central longitudinal cross-section from each sample of the DOC test was mapped using FT-NIR microscopy. Data were statistically analyzed according to the experimental design (α=0.05; ß=0.2). The radiant exposure in the violet wavelength range for Standard and Xtra-Power was 4.5 and 5.0 J/cm2, respectively; for the blue wavelength range the radiant exposure for Standard and Xtra-Power was 15.5 and 15.0 J/cm2, respectively. There was no statistical difference in the DOC using Standard or Xtra-Power light-curing modes, but the DOC was lower than the claimed by the manufacturer (4 mm). The DC was not significantly affected by the light-curing mode up to 4 mm in depth (p>0.05). According to exposure reciprocity law, the reduction in exposure time using the same radiant exposure did not affect the depth of cure of the bulk fill composite.
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Affiliation(s)
- Mateus Garcia Rocha
- Department of Restorative Dental Sciences, Operative Dentistry Division, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Jean-François Roulet
- Department of Restorative Dental Sciences, Operative Dentistry Division, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Mario Alexandre Coelho Sinhoreti
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, UNICAMP - Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | - Américo Bortolazzo Correr
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, UNICAMP - Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | - Dayane Oliveira
- Department of Restorative Dental Sciences, Operative Dentistry Division, College of Dentistry, University of Florida, Gainesville, FL, USA
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Li Q, Lin HL, Zheng M, Ozcan M, Yu H. Minimum Radiant Exposure and Irradiance for Triggering Adequate Polymerization of a Photo-Polymerized Resin Cement. MATERIALS 2021; 14:ma14092341. [PMID: 33946389 PMCID: PMC8124640 DOI: 10.3390/ma14092341] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 04/23/2021] [Accepted: 04/26/2021] [Indexed: 12/02/2022]
Abstract
This study aimed to establish the minimum radiant exposure and irradiance to trigger an adequate polymerization of a photo-polymerized resin cement. In total, 220 disc-shaped specimens (diameter of 10 mm and thickness of 0.1 mm) were fabricated using a photo-polymerized resin cement (Variolink N-transparent, Ivoclar Vivadent). To investigate the minimum radiant exposure, the specimens were polymerized with radiant exposures of 1, 2, 3, 4, 5, 6, and 18 J/cm2 (n = 20). During polymerization, the irradiance was maintained at 200 mW/cm2. To investigate the minimum irradiance, the specimens were polymerized with irradiances of 50, 100, 150, and 200 mW/cm2 (n = 20). During polymerization, the radiant exposure was maintained at the previously determined minimum radiant exposure. The Vickers microhardness (HV) and degree of conversion (DC) of the carbon double bond of the specimens were measured to determine the degree of polymerization of the specimens. The results were analyzed using one-way analysis of variance (ANOVA) and Tukey’s test (p < 0.05). In the investigation of the minimum radiant exposure, the HV and DC of the specimens polymerized with a radiant exposure from 1 to 5 J/cm2 were significantly lower than those with 18 J/cm2 (all p < 0.05). However, no significant difference in HV and DC was found between the specimens polymerized with 6 J/cm2 and 18 J/cm2 (p > 0.05). In the investigation of the minimum irradiance, the specimens polymerized with an irradiance of 50 mW/cm2 had significantly lower HV and DC than the specimens polymerized with an irradiance of 200 mW/cm2 (p < 0.05). However, no significant difference in the HV and DC was found among the specimens cured with irradiances of 100, 150, and 200 mW/cm2 (p > 0.05). In conclusion, the minimum radiant exposure and irradiance to trigger an adequate polymerization of the light-cured resin cement were 6 J/cm2 and 100 mW/cm2, respectively.
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Affiliation(s)
- Qi Li
- Fujian Key Laboratory of Oral Diseases, Fujian Provincial Engineering Research Center of Oral Biomaterial, Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou 350000, China; (Q.L.); (H.-L.L.)
- Fujian Provincial Governmental Hospital, Fuzhou 350000, China
| | - Hong-Lei Lin
- Fujian Key Laboratory of Oral Diseases, Fujian Provincial Engineering Research Center of Oral Biomaterial, Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou 350000, China; (Q.L.); (H.-L.L.)
| | - Ming Zheng
- Fujian Key Laboratory of Oral Diseases, Fujian Provincial Engineering Research Center of Oral Biomaterial, Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou 350000, China; (Q.L.); (H.-L.L.)
- Correspondence: (M.Z.); or (H.Y.)
| | - Mutlu Ozcan
- Division of Dental Biomaterials, Clinic for Reconstructive Dentistry, Center for Dental Medicine, University of Zurich, 8006 Zurich, Switzerland;
| | - Hao Yu
- Fujian Key Laboratory of Oral Diseases, Fujian Provincial Engineering Research Center of Oral Biomaterial, Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou 350000, China; (Q.L.); (H.-L.L.)
- Correspondence: (M.Z.); or (H.Y.)
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Alagha EI, Alagha MI. Microhardness Assessment of Two Nanohybrid Composite Resins with Two Curing Technologies. Open Access Maced J Med Sci 2021. [DOI: 10.3889/oamjms.2021.5868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
AIM:This study evaluated the influence of two light sources on the microhardness of two recent composite resins.
MATERIALS AND METHODS: A total of 120 specimens were prepared and divided into two groups according to the composite resin restoration used (Tetric EvoCeram Bulk fill) and (Universal Nanohybrid Mosaic). Each group was subdivided into four subgroups according to the curing sources used with different curing duration’s laser curing system (SIROLaser) for 10, 15, and 20 s and conventional blue light system (LED) for 20 s. A microhardness testing machine was used to assess the microhardness of Tetric EvoCeram Bulk fill and Universal Nanohybrid Mosaic. Two-way ANOVA statistical test was used for comparing resin composite and curing energy effect on different variable studied. One-way ANOVA followed by pair-wise Tukey’s post hoc tests was performed to detect significance between each composite subgroups and t-test for subgroups. P ≤ 0.05 is considered statistically significant in all tests.
RESULTS: LED cured Tetric EvoCeram Bulk fill composite resin recorded higher bottom to top ratio (B/T ratio) than laser cured one and the difference in B/T ratio between both energies was statistically non-significant. LED cured Mosaic composite resin recorded higher B/T ratio than laser cured one . The difference in bottom to top ratio between both curing devices was statistically significant.
CONCLUSION: SIROLaser Blue laser device increases the degree of polymerization and achieves better curing of composite resins than LED.
RECOMMENDATION: Different types of curing systems are present in the dental practice. The use of SIROLaser Blue laser to photopolymerize composite resin will offers proper polymerization properties.
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Luca BI, Ilie N. Estimation of the tolerance threshold for the irradiance of modern LED curing units when simulating clinically relevant polymerization conditions. Dent Mater J 2021; 40:750-757. [PMID: 33678801 DOI: 10.4012/dmj.2020-261] [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] [Indexed: 11/23/2022]
Abstract
The study aims to characterize various LED light curing units (LED-LCU) in order to determine the tolerance threshold for varying the polymerization conditions. Two violet-blue and two blue LED-LCUs were analyzed by using a laboratory-grade spectrophotometer system. Fifty-five curing conditions were simulated in each LED-LCU by varying the position (centered and with an offset of 3-mm to the left, right, lower and upper direction) and the exposure distance (0 mm to 10 mm in 1-mm steps). Irradiance decreased with increasing exposure distance, while the effect of the LCU position was significant and LCU-specific. Only one LED-LCU enables the irradiance threshold of 1,000 mW/cm2 to be achieved in all positions up to an exposure distance of 4 mm. LCUs with a more homogeneous light beam profile more easily tolerate deviations from the ideal curing conditions. The study enables dentists to identify the limits of modern LED-LCUs and to estimate potential deviations from ideal curing conditions for clinically relevant situations.
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Affiliation(s)
- Bianca-Ioana Luca
- Department of Conservative Dentistry and Periodontology, University Hospital
| | - Nicoleta Ilie
- Department of Conservative Dentistry and Periodontology, University Hospital
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The Photoinitiators Used in Resin Based Dental Composite-A Review and Future Perspectives. Polymers (Basel) 2021; 13:polym13030470. [PMID: 33540697 PMCID: PMC7867280 DOI: 10.3390/polym13030470] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 01/27/2021] [Accepted: 01/29/2021] [Indexed: 11/26/2022] Open
Abstract
The presented paper concerns current knowledge of commercial and alternative photoinitiator systems used in dentistry. It discusses alternative and commercial photoinitiators and focuses on mechanisms of polymerization process, in vitro measurement methods and factors influencing the degree of conversion and hardness of dental resins. PubMed, Academia.edu, Google Scholar, Elsevier, ResearchGate and Mendeley, analysis from 1985 to 2020 were searched electronically with appropriate keywords. Over 60 articles were chosen based on relevance to this review. Dental light-cured composites are the most common filling used in dentistry, but every photoinitiator system requires proper light-curing system with suitable spectrum of light. Alternation of photoinitiator might cause changing the values of biomechanical properties such as: degree of conversion, hardness, biocompatibility. This review contains comparison of biomechanical properties of dental composites including different photosensitizers among other: camphorquinone, phenanthrenequinone, benzophenone and 1-phenyl-1,2 propanedione, trimethylbenzoyl-diphenylphosphine oxide, benzoyl peroxide. The major aim of this article was to point out alternative photoinitiators which would compensate the disadvantages of camphorquinone such as: yellow staining or poor biocompatibility and also would have mechanical properties as satisfactory as camphorquinone. Research showed there is not an adequate photoinitiator which can be as sufficient as camphorquinone (CQ), but alternative photosensitizers like: benzoyl germanium or novel acylphosphine oxide photoinitiators used synergistically with CQ are able to improve aesthetic properties and degree of conversion of dental resin.
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Correlation of the mechanical and biological response in light-cured RBCs to receiving a range of radiant exposures: Effect of violet light. J Dent 2020; 105:103568. [PMID: 33385531 DOI: 10.1016/j.jdent.2020.103568] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/11/2020] [Accepted: 12/23/2020] [Indexed: 11/21/2022] Open
Abstract
OBJECTIVE This study correlates the mechanical and biological response of commercially available resin-based composites (RBCs) to clinically relevant light-curing conditions. METHODS Two RBCs (Venus and Venus Pearl; Kulzer) that use different monomer and photo-initiator systems, but have a similar filler volume and shade, were exposed to either just blue light, or violet and blue light from two different LCUs (Translux Wave and Translux 2Wave; Kulzer). Distance and exposure times were adjusted so that both LCUs delivered 5 similar levels of radiant exposures (RE) between 1.5 J/cm²-25 J/cm² in the blue wavelength range. Thus, the violet light was additional light. The top and bottom of 2-mm thick specimens were subjected to a depth-sensing indentation test (Martens hardness/HM, Vickers hardness/HV, indentation modulus/YHU, mechanical work/Wtotal, plastic deformation work/Wplas, creep/Cr). The viability of human gingival fibroblasts was assessed after three days of exposure to RBC eluates. One and multiple-way analysis of variance (ANOVA), the Tukey honestly significant difference (HSD) post-hoc tests (α = 0.05), t-test and a Spearman correlation analysis were used. RESULTS As the RE increased, the mechanical properties increased at a greater rate at the top compared to the bottom of the RBCs. Values measured at the bottom of 2-mm increments approached the values measured at the top only when RE > 25 J/cm² of blue light was delivered. Toxicity decreased with RE and elution cycles and was lower for Venus Pearl. Within one RE level, addition of violet light resulted in significantly improved properties (in 131 out of 150 comparisons, p < 0.05). This effect was stronger for Venus Pearl. There was a good correlation between mechanical and biological parameters. This correlation decreased as the number of eluates increased. CLINICAL SIGNIFICANCE The mechanical and biological response to variation in RE is interrelated. The addition of violet light has a positive effect, particularly at low RE.
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Sampaio CS, Pizarro PG, Atria PJ, Hirata R, Giannini M, Mahn E. Effect of Shortened Light-Curing Modes on Bulk-Fill Resin Composites. Oper Dent 2020; 45:496-505. [PMID: 32101499 DOI: 10.2341/19-101-l] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/28/2019] [Indexed: 11/23/2022]
Abstract
CLINICAL RELEVANCE Shortened light curing does not affect volumetric polymerization shrinkage or cohesive tensile strength but negatively affects the shear bond strength of some bulk-fill resin composites. When performing shortened light curing, clinicians should be aware of the light output of their light-curing units. SUMMARY Purpose: To evaluate volumetric polymerization shrinkage (VPS), shear bond strength (SBS) to dentin, and cohesive tensile strength (CTS) of bulk-fill resin composites (BFRCs) light activated by different modes.Methods and Materials: Six groups were evaluated: Tetric EvoCeram bulk fill + high mode (10 seconds; TEC H10), Tetric EvoFlow bulk fill + high mode (TEF H10), experimental bulk fill + high mode (TEE H10), Tetric EvoCeram bulk fill + turbo mode (five seconds; TEC T5), Tetric EvoFlow bulk fill + turbo mode (TEF T5), and experimental bulk fill + turbo mode (TEE T5). Bluephase Style 20i and Adhese Universal Vivapen were used for all groups. All BFRC samples were built up on human molar bur-prepared occlusal cavities. VPS% and location were evaluated through micro-computed tomography. SBS and CTS tests were performed 24 hours after storage or after 5000 thermal cycles; fracture mode was analyzed for SBS.Results: Both TEC H10 and TEE H10 presented lower VPS% than TEF H10. However, no significant differences were observed with the turbo-curing mode. No differences were observed for the same BFRC within curing modes. Occlusal shrinkage was mostly observed. Regarding SBS, thermal cycling (TC) affected all groups. Without TC, all groups showed higher SBS values for high mode than turbo mode, while with TC, only TEC showed decreased SBS from high mode to turbo modes; modes of fracture were predominantly adhesive. For CTS, TC affected all groups except TEE H10. In general, no differences were observed between groups when comparing the curing modes.Conclusions: Increased light output with a shortened curing time did not jeopardize the VPS and SBS properties of the BFRCs, although a decreased SBS was observed in some groups. TEE generally showed similar or improved values for the tested properties in a shortened light-curing time. The VPS was mostly affected by the materials tested, whereas the SBS was affected by the materials, curing modes, and TC. The CTS was not affected by the curing modes.
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Al-Zain AO, Platt JA. Effect of light-curing distance and curing time on composite microflexural strength. Dent Mater J 2020; 40:202-208. [PMID: 32999258 DOI: 10.4012/dmj.2020-002] [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] [Indexed: 11/23/2022]
Abstract
This study investigated the influence of curing distance on µ-flexural strength (µ-FS) of a nano-hybrid composite, cured using the manufacturer-recommended curing time (MCT), compared to a consistent radiant exposure (CRE) using three different light-curing units (LCUs). Beams (6×2×1 mm) were cured using the MCT or CRE with a quartz-tungsten-halogen (QTH); a single-emission-peak light-emitting-diode (SLED), or a multiple-emission-peak light-emitting-diode (MLED) LCU. Specimens were cured at 0-, 2- or 8-mm distances (n=10) and the bottom irradiance and CRE were measured using a Managing Accurate Resin Curing-Resin Calibrator spectrometer. µ-FS testing was performed, and data analyzed using two-way ANOVA and Tukey multiple comparison tests (α=0.05). Mean bottom irradiance was (25.4-99.7 mW/cm2) and CRE (0.31-1.11 J/cm2). µ-FS was 422.1-516.6 MPa (MCT) and 440.4-490.4 MPa (CRE). Comparing CRE to MCT showed that µ-FS significantly decreased using the CRE at 2-mm (QTH) or the MCT at 2- and 8-mm (SLED). µ-FS may be significantly impacted by the curing protocol.
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Affiliation(s)
- Afnan O Al-Zain
- Operative and Esthetic Dentistry Division, Restorative Dentistry Department, Faculty of Dentistry, King Abdulaziz University
| | - Jeffrey A Platt
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indiana University Purdue University Indianapolis
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Algamaiah H, Silikas N, Watts DC. Conversion kinetics of rapid photo-polymerized resin composites. Dent Mater 2020; 36:1266-1274. [DOI: 10.1016/j.dental.2020.07.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 07/21/2020] [Accepted: 07/21/2020] [Indexed: 10/23/2022]
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Influence of the photoactivation distance on the color and whiteness stability of resin-based composite after bleaching and aging. J Dent 2020; 99:103408. [DOI: 10.1016/j.jdent.2020.103408] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 06/01/2020] [Accepted: 06/07/2020] [Indexed: 11/24/2022] Open
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The effect of rapid high-intensity light-curing on micromechanical properties of bulk-fill and conventional resin composites. Sci Rep 2020; 10:10560. [PMID: 32601442 PMCID: PMC7324583 DOI: 10.1038/s41598-020-67641-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 06/11/2020] [Indexed: 01/08/2023] Open
Abstract
Rapid high-intensity light-curing of dental resin composites is attractive from a clinical standpoint due to the prospect of time-savings. This study compared the effect of high-intensity (3 s with 3,440 mW/cm2) and conventional (10 s with 1,340 mW/cm2) light-curing on micromechanical properties of conventional and bulk-fill resin composites, including two composites specifically designed for high-intensity curing. Composite specimens were prepared in clinically realistic layer thicknesses. Microhardness (MH) was measured on the top and bottom surfaces of composite specimens 24 h after light-curing (initial MH), and after subsequent immersion for 24 h in absolute ethanol (ethanol MH). Bottom/top ratio for initial MH was calculated as a measure of depth-dependent curing effectiveness, whereas ethanol/initial MH ratio was calculated as a measure of crosslinking density. High-intensity light-curing showed a complex material-dependent effect on micromechanical properties. Most of the sculptable composites showed no effect of the curing protocol on initial MH, whereas flowable composites showed 11–48% lower initial MH for high-intensity curing. Ethanol/initial MH ratios were improved by high-intensity curing in flowable composites (up to 30%) but diminished in sculptable composites (up to 15%). Due to its mixed effect on MH and crosslinking density in flowable composites, high-intensity curing should be used with caution in clinical work.
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Dressano D, Salvador MV, Oliveira MT, Marchi GM, Fronza BM, Hadis M, Palin WM, Lima AF. Chemistry of novel and contemporary resin-based dental adhesives. J Mech Behav Biomed Mater 2020; 110:103875. [PMID: 32957185 DOI: 10.1016/j.jmbbm.2020.103875] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 05/12/2020] [Accepted: 05/20/2020] [Indexed: 12/23/2022]
Abstract
The chemistry of resin-based dental adhesives is critical for its interaction with dental tissues and long-term bonding stability. Changes in dental adhesives composition influences the materials' key physical-chemical properties, such as rate and degree of conversion, water sorption, solubility, flexural strength and modulus, and cohesive strength and improves the biocompatibility to dental tissues. Maintaining a suitable reactivity between photoinitiators and monomers is important for optimal properties of adhesive systems, in order to enable adequate polymerisation and improved chemical, physical and biological properties. The aim of this article is to review the current state-of-the-art of dental adhesives, and their chemical composition and characteristics that influences the polymerisation reaction and subsequent materials properties and performance.
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Affiliation(s)
- Diogo Dressano
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av Limeira, 901 Mail Box 52, Piracicaba, Sao Paulo, 13414-903, Brazil.
| | - Marcos V Salvador
- Dental Research Division, Paulista University, Sao Paulo, Rua Doutor Bacelar, 1212, CEP: 04026-002, Brazil.
| | | | - Giselle Maria Marchi
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av Limeira, 901 Mail Box 52, Piracicaba, Sao Paulo, 13414-903, Brazil.
| | - Bruna M Fronza
- Department of Biomaterials and Oral Biology, University of São Paulo, 2227 Prof. Lineu Prestes Ave, 05508-000, São Paulo, SP, Brazil.
| | - Mohammed Hadis
- Dental Materials Science, Birmingham Dental School and Hospital, College of Medical and Dental Science, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham, B5 7EG, UK.
| | - William M Palin
- Dental Materials Science, Birmingham Dental School and Hospital, College of Medical and Dental Science, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham, B5 7EG, UK.
| | - Adriano Fonseca Lima
- Dental Research Division, Paulista University, Sao Paulo, Rua Doutor Bacelar, 1212, CEP: 04026-002, Brazil.
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Al-Zain AO, Marghalani HY. Influence of Light-curing Distances on Microflexural Strength of Two Resin-based Composites. Oper Dent 2020; 45:297-305. [DOI: 10.2341/19-001-l] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
Objective:
Our objective was to investigate the influence of different curing distances on microflexural strength and the microflexural modulus of two resin-based composites.
Methods:
Two nanohybrid composites were used; Filtek Z250 (Z250) and Tetric EvoCeram (TEC). Rectangular specimens were prepared (2-mm wide × 1-mm deep × 6-mm long) light cured according to the manufacturer's instructions at 0-mm, 2-mm, and 8-mm distances (n=10) and were stored wet at 37°C for 24 hours. A microflexural strength test was performed using a universal testing machine at a crosshead speed of 1 mm/min. The microflexural strength and microflexural modulus data were analyzed using a two-way analysis of variance followed by a Tukey multiple comparison post hoc test (α=0.05).
Results:
The TEC composite had a significantly higher microflexural strength at an 8-mm distance compared with the 0-mm distance. The Z250 composite expressed significantly higher microflexural strength, at 2-mm and 8-mm compared with the 0-mm distance. TEC showed a significantly higher microflexural modulus at an 8-mm distance compared with the 0-mm and 2-mm distances. Z250 also exhibited a significantly higher microflexural modulus at the 2-mm distance, compared with the 8-mm distance. In total, Z250 presented a significantly higher microflexural strength and modulus compared with TEC.
Conclusion:
Curing the explored composites at 2-mm or 8-mm distances from the specimen surface did not have a significant influence on microflexural strength but did significantly affect the microflexural modulus.
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Affiliation(s)
- AO Al-Zain
- Afnan O Al-Zain, BDS, MSD, PhD, Diploma of Professional Development in Teaching and Learning, Operative and Esthetic Dentistry Division, Restorative Dentistry Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - HY Marghalani
- Hanadi Y Marghalani, BDS, MSc, PhD, DRBBA-Research Group, Operative and Esthetic Dentistry Division, Restorative Dentistry Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
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Palagummi SV, Hong T, Wang Z, Moon CK, Chiang MYM. Resin viscosity determines the condition for a valid exposure reciprocity law in dental composites. Dent Mater 2019; 36:310-319. [PMID: 31866065 DOI: 10.1016/j.dental.2019.12.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 12/04/2019] [Accepted: 12/04/2019] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To provide conditions for the validity of the exposure reciprocity law as it pertains to the photopolymerization of dimethacrylate-based dental composites. METHODS Composites made from different mass ratios of resin blends (Bis-GMA/TEGDMA and UDMA/TEGDMA) and silanized micro-sized glass fillers were used. All the composites used camphorquinone and ethyl 4-dimethylaminobenzoate as the photo initiator system. A cantilever beam-based instrument (NIST SRI 6005) coupled with NIR spectroscopy and a microprobe thermocouple was used to simultaneously measure the degree of conversion (DC), the polymerization stress (PS) due to the shrinkage, and the temperature change (TC) in real time during the photocuring process. The instrument has an integrated LED light curing unit providing irradiances ranging from 0.01W/cm2 to 4W/cm2 at a peak wavelength of 460nm (blue light). Vickers hardness of the composites was also measured. RESULTS For every dental composite there exists a minimum radiant exposure required for an adequate polymerization (i.e., insignificant increase in polymerization with any further increase in the radiant exposure). This minimum predominantly depends on the resin viscosity of composite and can be predicted using an empirical equation established based on the test results. If the radiant exposure is above this minimum, the exposure reciprocity law is valid with respect to DC for high-fill composites (filler contents >50% by mass) while invalid for low-fill composites (that are clinically irrelevant). SIGNIFICANCE The study promotes better understanding on the applicability of the exposure reciprocity law for dental composites. It also provides a guidance for altering the radiant exposure, with the clinically available curing light unit, needed to adequately cure the dental composite in question.
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Affiliation(s)
- Sri Vikram Palagummi
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, MD, United States
| | - Taeseung Hong
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, MD, United States; Department of Materials Science and Engineering, Pukyong National University, Busan, Republic of Korea
| | - Zhengzhi Wang
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei, China
| | - Chang Kwon Moon
- Department of Materials Science and Engineering, Pukyong National University, Busan, Republic of Korea
| | - Martin Y M Chiang
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, MD, United States.
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Kanamori Y, Takahashi R, Nikaido T, Bamidis EP, Burrow MF, Tagami J. The effect of curing mode of a high-power LED unit on bond strengths of dualcure resin cements to dentin and CAD/CAM resin blocks. Dent Mater J 2019; 38:947-954. [PMID: 31406096 DOI: 10.4012/dmj.2018-344] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The purpose of this study was to investigate the effects of curing mode with a high-power LED curing unit (VALO) in terms of microtensile bond strength (μTBS) to dentin and microhardness of two dual-cure resin cements. Panavia V5 (V5) and Rely X Ultimate (RXU) were polymerized using one of three curing modes with VALO or self-cure mode to bond a CAD/CAM resin block to a flat dentin surface. Specimens were sectioned and subjected to μTBS test. Vickers hardness values of V5 and RXU were also measured. Two-way ANOVA indicated curing mode and resin cement affected μTBS. For self-cure mode, V5 had significantly higher μTBS than RXU (p<0.05). Higher irradiance did not always provide higher μTBS of dual-cure resin cement to dentin. One-way ANOVA indicated the curing modes affected microhardness of each cement. As for microhardness of RXU, there were significant differences between selfcure mode and light cure modes (p<0.05).
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Affiliation(s)
- Yuna Kanamori
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU)
| | - Rena Takahashi
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU)
| | - Toru Nikaido
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU).,Department of Operative Dentistry, Division of Oral Functional Science and Rehabilitation, School of Dentistry, Asahi University
| | - Elias P Bamidis
- Department of Restorative Dentistry and Periodontology, University Hospital of Munich, Ludwig-Maximilians-University
| | | | - Junji Tagami
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU)
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Erickson RL, Barkmeier WW. Comparisons of ISO depth of cure for a resin composite in stainless-steel and natural-tooth molds. Eur J Oral Sci 2019; 127:556-563. [PMID: 31553092 DOI: 10.1111/eos.12652] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The purpose of this study was to compare the depth of cure (DOC) of a resin-based composite (RBC) using the ISO DOC protocol with stainless-steel and molar-tooth molds (4 mm cylindrical cavity). The tooth mold included testing with and without the occlusal surface being covered with black tape around the cavity opening. The RBC was cured with either halogen (HAL) or light-emitting diode (LED) light. The results showed that specimens made in the non-taped tooth mold had DOCs that were significantly greater (28%-35%) than those in the stainless-steel mold. The taped tooth mold also produced significantly greater DOCs, but only by 6%-8%. Knoop hardness (KNH) measurements along the central axis of the RBC specimens showed that depths for 80% of maximum hardness were substantially greater than those determined by the ISO DOC protocol but were limited to the center and quickly dropped below 80% in a lateral direction. The KHN mapping for each of the three molds found that the ISO DOCs could validate a KHN of ≥80% across the RBC to the periphery, only for the non-taped tooth mold. This was due to light incident on the tooth surrounding the RBC being scattered into the RBC.
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Affiliation(s)
- Robert L Erickson
- Department of General Dentistry, Creighton University School of Dentistry, Omaha, NE, USA
| | - Wayne W Barkmeier
- Department of General Dentistry, Creighton University School of Dentistry, Omaha, NE, USA
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Lima AF, Salvador MVO, Dressano D, Saraceni CHC, Gonçalves LS, Hadis M, Palin WM. Increased rates of photopolymerisation by ternary type II photoinitiator systems in dental resins. J Mech Behav Biomed Mater 2019; 98:71-78. [PMID: 31203099 DOI: 10.1016/j.jmbbm.2019.06.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/04/2019] [Accepted: 06/05/2019] [Indexed: 12/26/2022]
Abstract
To evaluate the effects of Type I and Type II photoinitiator systems on curing efficiency, degree of conversion (DC) and chemico-physical properties of resin based materials. A comonomer base containing 50%wt 2.2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane (bis-GMA) and 50%wt triethyleneglycol dimethacrylate (TEGDMA) was formulated with either 0.5 or 1mol% of Type II camphoroquinone (CQ), Type I monoacylphosphine oxide (MAPO) or bis-acylphosphine oxide (BAPO) photoinitiators. The Type II system was either a binary (1: 2 CQ:amine) or ternary system (1: 2 CQ:amine + 0.5 mol% DPI). Degree and rate of polymerization was measured by Fourier Transform Infrared Spectroscopy (FTIR). Knoop micro-hardness prior to and following ethanol immersion was assessed. Flexural strength and modulus was measured under three-point bend test. Water sorption and solubility was also evaluated. The photoinitiator absorption spectra and the total absorbed energy per unit volume (Eabs) for 0.5mol% photoinitiator in each material was calculated. Despite the reduced total absorbed energy per unit volume for CQ based systems, ternary Type II system significantly improved curing efficiency (P < 0.05) compared to both Type I photoinitiators and degree of conversion compared to MAPO only, whilst exhibiting comparable mechanical and physical properties compared to both Type I based materials at equivalent molar concentrations of photoinitiator (P > 0.05). Ternary Type II systems is an efficient alternative to improve the polymerization of resin materials, promoting similar or even better properties than Type I initiators. DPI can increase the reactivity of CQ systems and promote polymerization rates superior than Type I photoinitiators.
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Affiliation(s)
- Adriano Fonseca Lima
- Dental Research Division, Paulista University, Sao Paulo Brazil. Rua Doutor Bacelar, 1212. CEP: 04026-002, Sao Paulo, Brazil.
| | | | - Diogo Dressano
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Piracicaba, Brazil. Av Limeira, 901 Mail Box 52, Piracicaba, Sao Paulo, 13414-903, Brazil.
| | - Cintia Helena Coury Saraceni
- Dental Research Division, Paulista University, Sao Paulo Brazil. Rua Doutor Bacelar, 1212. CEP: 04026-002, Sao Paulo, Brazil.
| | - Luciano Souza Gonçalves
- Department of Conservative Dentistry, Federal University of Rio Grande do Sul School of Dentistry, Av. Paulo Gama, 110 - Farroupilha, Porto Alegre, RS, 90040-060, Porto Alegre, RS, Brazil.
| | - Mohammed Hadis
- Biomaterials Unit, University of Birmingham, College of Medical and Dental Sciences, School of Dentistry, St Chad's Queensway, Birmingham, B4 6NN, UK.
| | - William M Palin
- Biomaterials Unit, University of Birmingham, College of Medical and Dental Sciences, School of Dentistry, St Chad's Queensway, Birmingham, B4 6NN, UK.
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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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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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Cuevas-Suárez CE, Meereis CTW, D'accorso N, Macchi R, Ancona-Meza AL, Zamarripa-Calderón E. Effect of radiant exposure and UV accelerated aging on physico-chemical and mechanical properties of composite resins. J Appl Oral Sci 2019; 27:e20180075. [PMID: 30624462 PMCID: PMC6322643 DOI: 10.1590/1678-7757-2018-0075] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 09/09/2018] [Indexed: 12/04/2022] Open
Abstract
Currently, there is no consensus in terms of defining the minimum radiant exposure values necessary for achieving adequate properties of composite resin. In addition, the long-term influence that radiant exposure has on the properties of composite resins is still questionable. Objective: The objective of this study was to evaluate the effect of radiant exposure and UV accelerated aging on the physico-chemical and mechanical properties of micro-hybrid and nanofilled composite resins. Material and Methods: A nanofilled (Filtek Supreme; 3M ESPE) and a micro-hybrid composite resin (Filtek Z250; 3M ESPE) were investigated under different radiant exposures (3.75, 9, and 24 J/cm2) and UV accelerated aging protocols (0, 500, 1000, and 1500 aging hours). The degree of conversion (DC), flexural strength (FS), modulus (M), water sorption (WS), and solubility (WL) were evaluated. The results obtained were analyzed using two-way ANOVA and Tukey's test. Comparisons were performed using a significance level of α=0.05. Results: The DC, FS, and M were found to be significantly influenced by both radiant exposure and accelerated aging time. The DC and EM increased with radiant exposure in the no-aging group (0-hour aging) for both micro-hybrid and nanofilled composites, whereas no correlation was found after accelerated aging protocols. WS and WL of micro-hybrid and nanofilled composite resins were scarcely affected by radiant exposure (p>0.05), whereas they were significantly reduced by accelerated aging (p<0.001). Conclusions: Although increasing radiant exposure affected the degree of conversion and mechanical properties of micro-hybrid and nanofilled composites, no influence on the hydrolytic degradation of the material was observed. In contrast, UV accelerated aging affected both the physico-chemical and mechanical properties of the composites.
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Affiliation(s)
- Carlos Enrique Cuevas-Suárez
- Universidad Autónoma del Estado de Hidalgo, Instituto de Ciencias de la Salud, Área Académica de Odontología, Pachuca de Soto, México
| | - Carine Tais Walter Meereis
- Universidade Federal dos Vales do Jequitinhonha e Mucuri, Programa de Pós-Graduação em Odontologia, Diamantina, Minas Gerais, Brasil
| | - Norma D'accorso
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Orgánica, Buenos Aires, Argentina
| | - Ricardo Macchi
- Universidad de Buenos Aires, Facultad de Odontología, Departamento de Materiales Dentales, Buenos Aires, Argentina
| | - Adriana Leticia Ancona-Meza
- Universidad Autónoma del Estado de Hidalgo, Instituto de Ciencias de la Salud, Área Académica de Odontología, Pachuca de Soto, México
| | - Eliezer Zamarripa-Calderón
- Universidad Autónoma del Estado de Hidalgo, Instituto de Ciencias de la Salud, Área Académica de Odontología, Pachuca de Soto, México
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Cadenaro M, Maravic T, Comba A, Mazzoni A, Fanfoni L, Hilton T, Ferracane J, Breschi L. The role of polymerization in adhesive dentistry. Dent Mater 2019; 35:e1-e22. [DOI: 10.1016/j.dental.2018.11.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 11/12/2018] [Accepted: 11/13/2018] [Indexed: 10/27/2022]
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Aldossary MS, Abu Hajia SS, Santini A. Transmission de l’énergie lumineuse au travers de six marques différentes d’attaches orthodontiques. Int Orthod 2018; 16:638-651. [DOI: 10.1016/j.ortho.2018.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
OBJECTIVE To measure Total Light Energy (TLE) Transmission through six makes of ceramic orthodontic brackets alone and bracket-plus-adhesive samples, using the MARC™-Resin Calibrator (RC). METHODS Six makes, three each monocrystalline (M) and polycrystalline (P) were used; PureSapphire (M), SPA Aesthetic (M), Ghost (M), Mist (P), Reflections (P), and Dual Ceramic (P). The Ortholux™ Light Curing Unit (LCU) was used to cure the orthodontic adhesive Transbond™XT. The LCU's tip irradiance was measured and TLE transmitted through the ceramic bracket was obtained, then adhesive added to the bracket, and transmitted TLE measured through bracket-plus-adhesive samples. The LCU was set at five seconds as recommended for curing adhesive through ceramic brackets. RESULTS Mean tip irradiance was 1859.2±16.2mW/cm2. The TLE transmitted through brackets alone ranged 1.7 to 3.9J/cm2, in the descending order: Ghost>Pure Sapphire>Reflections>Mist>SPA Aesthetics>Dual Ceramic. The TLE transmitted through bracket-plus-adhesive samples ranged 1.6 to 3.7J/cm2, in the descending order: Ghost>Mist>Reflections>Pure Sapphire>SPA Aesthetics>Dual Ceramic. TLE was reduced with the addition of adhesive (range -0.1 to -0.7J/cm2). There was a significant difference for Pure Sapphire, Reflections, and Mist (P<0.05), but not for SPA Aesthetics, Ghost, and Dual Ceramic. There was no overall significant difference between the monocrystalline and polycrystalline makes. The two best makes were of the monocrystalline type, concerning TLE transmission, but with the exception of polycrystalline Dual Ceramic; the next worst make was a monocrystalline bracket, SPA Aesthetics. CONCLUSION Light energy attenuation through ceramic orthodontic brackets is make-dependent, with no overall difference between monocrystalline and polycrystalline brackets. Light energy is further attenuated with the addition of resin-based orthodontic adhesive.
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Lima RBW, Troconis CCM, Moreno MBP, Murillo-Gómez F, De Goes MF. Depth of cure of bulk fill resin composites: A systematic review. J ESTHET RESTOR DENT 2018; 30:492-501. [PMID: 30375146 DOI: 10.1111/jerd.12394] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 05/13/2018] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To evaluate scientific evidence regarding depth of cure of bulk-fill resin composites (BFRCs) and related factors. MATERIAL AND METHODS PubMed/Medline, Embase, Scopus, and ISI Web of Science databases were accessed from October 2016 to May 2017. Investigations published in English language, assessing depth of cure of BFRCs by microhardness test and/or degree of conversion (DC) were included. Studies using exclusively ISO 4049, employing specimens deepness less than 4 mm, as well as those not reporting exposure time and/or irradiance from light curing units (LCUs) were excluded. RESULTS In total, 742 studies were found from which 33 were included. From 21 studies evaluating BFRCs microhardness, 10 showed acceptable bottom/top ratios (≥0.8) for all tested materials. However, material-dependent results and non-satisfactory bottom/top microhardness ratios (<0.8) were reported in 9 and 2 investigations, respectively. From 19 studies that assessed DC, 11 showed acceptable results (≥50%) for all tested BFRCs, while 8 studies reported material-dependent outcomes. Overall, irradiance from LCUs ranged from 650 to 1330 mW/cm2 and exposure time from 5 to 60 seconds. Favorable depth of cure results were observed with the use of LCUs emitting irradiance ≥1000 mW/cm2 and exposure times ≥20 seconds. CONCLUSIONS High depth of cure rates by BFRCs, depends on some factors as material, irradiance and exposure time. Polywave LCUs were useful but not essential on polymerizing alternative photoinitiator-containing BFRC. CLINICAL SIGNIFICANCE LED curing devices (polywave or monowave) displaying an irradiance ≥1000 mW/cm2 and 20 seconds of exposure time are imperative to accomplish successful polymerization of most BFRCs.
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Affiliation(s)
- Renally Bezerra Wanderley Lima
- Department of Restorative Dentistry (Dental Materials Area), Piracicaba Dental School, University of Campinas - UNICAMP, Avenida Limeira, Campinas, São Paulo, 13414-903, Brazil
| | - Cristhian Camilo Madrid Troconis
- Department of Restorative Dentistry (Dental Materials Area), Piracicaba Dental School, University of Campinas - UNICAMP, Avenida Limeira, Campinas, São Paulo, 13414-903, Brazil
| | - Marina Barrêto Pereira Moreno
- Department of Restorative Dentistry (Dental Materials Area), Piracicaba Dental School, University of Campinas - UNICAMP, Avenida Limeira, Campinas, São Paulo, 13414-903, Brazil
| | - Fabián Murillo-Gómez
- Department of Restorative Dentistry (Dental Materials Area), Piracicaba Dental School, University of Campinas - UNICAMP, Avenida Limeira, Campinas, São Paulo, 13414-903, Brazil.,Department of Restorative Dentistry, School of Dentistry, University of Costa Rica-UCR, Rodrigo Facio "Campus,", San José, Costa Rica
| | - Mario Fernando De Goes
- Department of Restorative Dentistry (Dental Materials Area), Piracicaba Dental School, University of Campinas - UNICAMP, Avenida Limeira, Campinas, São Paulo, 13414-903, Brazil
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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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Ye Q, Abedin F, Parthasarathy R, Spencer P. Photoinitiators in Dentistry: Challenges and Advances. PHOTOPOLYMERISATION INITIATING SYSTEMS 2018. [DOI: 10.1039/9781788013307-00297] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Photopolymerization is used in a wide range of clinical applications in dentistry and the demand for dental materials that can restore form, function and esthetics is increasing rapidly. Simultaneous with this demand is the growing need for photoinitiators that provide effective and efficient in situ polymerization of dental materials using visible light irradiation. This chapter reviews the fundamentals of Type I and II photoinitiators. The advantages and disadvantages of these photoinitiators will be considered with a particular focus on parameters that affect the polymerization process in the oral cavity. The chapter examines recent developments in photoinitiators and opportunities for future research in the design and development of photoinitiators for dental applications. Future research directions that employ computational models in conjunction with iterative synthesis and experimental methods will also be explored in this chapter.
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Affiliation(s)
- Qiang Ye
- Institute for Bioengineering Research, School of Engineering, University of Kansas 1530 W. 15th St Lawrence KS 66045 USA
| | - Farhana Abedin
- Electromechanical Engineering Technology program, College of Engineering, California State Polytechnic University Pomona 3801 W. Temple Ave Pomona CA 91768 USA
| | - Ranganathan Parthasarathy
- Nanomaterials Research Lab, Tennessee State University 3500 John A Merritt Blvd Nashville TN 37209 USA
| | - Paulette Spencer
- Institute for Bioengineering Research, School of Engineering, University of Kansas 1530 W. 15th St Lawrence KS 66045 USA
- Department of Mechanical Engineering, University of Kansas 1530 W. 15th St Lawrence KS 66045 USA
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Maghaireh GA, Price RB, Abdo N, Taha NA, Alzraikat H. Effect of Thickness on Light Transmission and Vickers Hardness of Five Bulk-fill Resin-based Composites Using Polywave and Single-peak Light-emitting Diode Curing Lights. Oper Dent 2018; 44:96-107. [PMID: 29953339 DOI: 10.2341/17-163-l] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVES: This study compared light transmission through different thicknesses of bulk-fill resin-based composites (RBCs) using a polywave and a single-peak light-emitting diode light-curing unit (LCU). The effect on the surface hardness was also evaluated. METHODS: Five bulk-fill RBCs were tested. Specimens (n=5) of 1-, 2-, 4-, or 6-mm thickness were photopolymerized for 10 seconds from the top using a polywave (Bluephase Style) or single-peak (Elipar S10) LCU, while a spectrophotometer monitored in real time the transmitted irradiance and radiant exposure reaching the bottom of the specimen. After 24 hours of storage in distilled water at 37°C, the Vickers microhardness (VH) was measured at top and bottom. Results were analyzed using multiple-way analysis of variance, Tukey post hoc tests, and multivariate analysis (α=0.05). RESULTS: The choice of LCU had no significant effect on the total amount of light transmitted through the five bulk-fill RBCs at each thickness. There was a significant decrease in the amount of light transmitted as the thickness increased for all RBCs tested with both LCUs ( p<0.001). Effect of LCU on VH was minimal (ηp2=0.010). The 1-, 2-, and 4-mm-thick specimens of SDR, X-tra Fill, and Filtek Bulk Restorative achieved a VHbottom/top ratio of approximately 80% when either LCU was used. CONCLUSIONS: The total amount of light transmitted through the five bulk-fill RBCs was similar at the different thicknesses using either LCU. The polywave LCU used in this study did not enhance the polymerization of the tested bulk-fill RBCs when compared with the single-peak LCU.
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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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Ilie N, Luca BI. Efficacy of Modern Light Curing Units in Polymerizing Peripheral Zones in Simulated Large Bulk-fill Resin-composite Fillings. Oper Dent 2018; 43:416-425. [PMID: 29570023 DOI: 10.2341/17-095-l] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The variation in micro-hardness (HV) within simulated large cavities (10 × 6 mm) filled in one increment with three bulk-fill resin-based composites (BF-RBC) was assessed by means of a universal hardness device. Modern blue and violet-blue light curing units (LCUs) were applied in three different positions, by rotating the LCU in 120° steps. The exposure distance was 3 mm. One center and two peripheral (4-mm apart from the center) HV line profiles were measured in 0.5-mm steps at 24 hours postpolymerization to calculate the depth of cure (DOC). Incident light, irradiance, and spectral distribution were recorded. A multivariate analysis (general linear model) assessed the effect of the varied parameters as well as their interaction terms on HV and DOC. The effect of LCU rotation was not significant ( p=0.109). The DOC varied between 3.46 mm and 5.50 mm and was more strongly influenced by the BF-RBC ( p<0.001, ηP2=0.774), followed by the width of specimen ( p<0.001, ηP2=0.554), while the influence of the LCU was very low ( p<0.06, ηP2=0.070). Whether a BF-RBC filling is cured as well in the periphery as in the center depends more on the material than on the curing unit used.
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