Volumetric shrinkage and film thickness of cementation materials for veneers: An in vitro 3D microcomputed tomography analysis

Sampaio, Camila S.; Barbosa, João Malta; Cáceres, Eduardo; Rigo, Lindiane Cogo; Coelho, Paulo G.; Bonfante, Estevam A.; Hirata, Ronaldo

doi:10.1016/j.prosdent.2016.08.029

Cited by 37 publications

(37 citation statements)

References 24 publications

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“…In the present study it was observed that the prewarming of nanohybrid resin composite reduced its film thickness to be similar to the film thickness of resin cement, and it is well known that film thickness is an important factor when luting indirect restorations because thick film thickness leads to marginal misfit, allows great amount of resin material to be polymerized with great volumetric shrinkage and so high susceptibility of failure. (7) In accordance to the observations of this study, Sampaio et al (22) found that the thinner film thickness was formed by the pre-heated conventional composite, probably that occurred because temperature increased agitation of molecules and allowed mass plasticization of unpolymerized material. Moreover preheating provides a lute with a smaller coefficient of thermal expansion, with less polymerization shrinkage and with greater wear resistance at restoration margins compared to conventional resin luting cement.…”

Section: Daronch Et Alsupporting

confidence: 90%

Effect of Preheating Cycles on Microshear Bond Strength of Nanohybrid Resin Composite Luted to CAD/CAM Ceramic

Aboushahba

Korayem²,

Younis

2021

Egyptian Dental Journal

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Objective: This study aimed to investigate the microshear bond strength of adhesive resin cement to Leucite-reinforced CAD/CAM ceramic and compare it with that of prewarmed nanohybrid resin composite. Materials and methods: Sixty Empress CAD ceramic plates were prepared. Each ceramic plate received five Tygon tube micro-cylinders filled with bonding agents creating 5 resinous micro-cylinders on each ceramic plate. In the first group (GpA), they were filled with resin cement, nanohybrid resin composite as a bonding agent was applied in the second group (GpB), after warming at 50℃, in the third group (GpC), two prewarming cycles were performed. Lightcuring for 20seconds was applied. Micro-shear bond strength testing (μSBS) was performed using universal testing machine with a crosshead speed of 1 mm/min until failure occurred. The μSBS was calculated in MPa by dividing the load (Newton) over the respective surface area (mm 2). Data were tabulated and analyzed and showed normal distribution when checked using Kolmogorov-Smirnov test. One-way ANOVA used to compare between the tested groups for μSBS data followed by Tukey HSD post-hoc test for pairwise comparisons. Significant level was set at 5% (α=0.05). Results: One-way ANOVA showed a significant difference between tested groups (p<0.001). Where heated composite (two prewarming cycle) showed the highest mSBS compared to other groups (p<0.05). Nevertheless, heated composite (one prewarming cycle) showed an improved μSBS compared to resin cement group, but the increase was insignificant (p=0.081). Conclusion: Pre-heated nanohybrid resin composites seem to be a potential alternative to resin cement to lute ceramic restorations.

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Section: Daronch Et Alsupporting

confidence: 90%

Effect of Preheating Cycles on Microshear Bond Strength of Nanohybrid Resin Composite Luted to CAD/CAM Ceramic

Aboushahba

Korayem²,

Younis

2021

Egyptian Dental Journal

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“…Thicker film thicknesses may lead to the marginal misfit of these indirect restorations. Also, due to the greater amount of resin material to be polymerized, a greater volumetric shrinkage would also be expected, increasing the susceptibility to failure (14). The thinner film thickness formed by the conventional composite that was pre-heated probably occurs due to the increased agitation of molecules and mass plasticization of unpolymerized material, which reduces the viscosity (15).…”

Section: Discussionmentioning

confidence: 99%

Influence of Pre-Heating Regular Resin Composites and Flowable Composites on Luting Ceramic Veneers with Different Thicknesses

et al. 2019

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The aim of this study was to evaluate of pre-heating, filler contents and ceramic thickness on film thickness, microshear bond strength, degree of conversion and color change on ceramic veneers. Two experimental composites were prepared (Bis-GMA/UDMA/BisEMA/ TEGDMA), with different amounts of filler (65% or 50%wt) simulating a conventional and a flowable composite. The flowable (F) was used at room temperature and, the conventional either at room temperature (C) or pre-heated (CPH). Disk-shaped ceramics with different thickness (0.4 mm, 0.8 mm, 1.5 mm) were prepared. The film thickness was evaluated according to the ISO 4049 (n=10). The microshear bond strength (n=10) was evaluated in enamel using tubing specimens light-cured through the ceramic veneer. The degree of conversion was evaluated using Raman spectroscopy. The color change of the ceramic restorations (n=10) was evaluated by spectrophotometry. The results were submitted to 2-way ANOVA and Tukey’s post hoc test (a=5%). For the film thickness 1-way ANOVA was used (a=5%). The C presented the thicker film thickness; the CPH produced a similar film thickness in comparison to the F. All composites showed similar microshear bond strength. The degree of conversion of the F was higher than the C and CPH. The degree of conversion of the composites photo-activated through a 0.4 mm was higher than the composites photo-activated through thicker ceramics. The C showed the highest color change, while the CPH showed similar color change to the F. In conclusion, pre-heated conventional composites seem to be a potential alternative to lute ceramic veneers such as the flowable composites.

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“…µCT analysis has been an important tool to quantify and evaluate not only volumetric polymerization shrinkage 20,22,41) , but also to characterize the restorative material volumetric distribution such as fillers or presence of voids 18,22,42,43) . This method has been shown to depict locations of composite shrinkage when the substrate adherent was uniform, revealing gap formation regions and regions of potential interfacial failure 24) .…”

Section: Discussionmentioning

confidence: 99%

Micro-computed tomography evaluation of volumetric polymerization shrinkage and degree of conversion of composites cured by various light power outputs

et al. 2018

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This study evaluated the influence of different light-curing modes on the volumetric polymerization shrinkage and degree of conversion of a composite resin at different locations using micro-computed tomography and Fourier transform infrared spectroscopy (FTIR). Specimens were divided into 4 groups based on the light-curing mode used (Bluephase 20i): 1 -High (1,200 mW/cm 2 ); 2 -Low (650 mW/cm 2 ); 3 -Soft-start (650-1,200 mW/cm 2 ); and 4 -Turbo (2,000 mW/cm 2 ). Degree of conversion was calculated by the measurement of the peak absorbance height of the uncured and cured materials at the specific wavenumbers, and was performed by FTIR 48 h after curing resin samples. Degree of conversion was analyzed using two-way ANOVA. No significant differences were observed independent of the region of the restoration investigated (p>0.05). Different curing modes did not influence volumetric shrinkage neither degree of conversion of class I composite resin restorations.

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Volumetric shrinkage and film thickness of cementation materials for veneers: An in vitro 3D microcomputed tomography analysis

Cited by 37 publications

References 24 publications

Effect of Preheating Cycles on Microshear Bond Strength of Nanohybrid Resin Composite Luted to CAD/CAM Ceramic

Effect of Preheating Cycles on Microshear Bond Strength of Nanohybrid Resin Composite Luted to CAD/CAM Ceramic

Influence of Pre-Heating Regular Resin Composites and Flowable Composites on Luting Ceramic Veneers with Different Thicknesses

Micro-computed tomography evaluation of volumetric polymerization shrinkage and degree of conversion of composites cured by various light power outputs

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