Shrinkage Stresses Generated during Resin-Composite Applications: A Review

Filtek Silorane showed acceptable clinical performance after one year. However, the lowshrinkage resin combined with the self-etch adhesive did not provide any advantage over the methacrylate-based composite combined with the total-etch adhesive. SUMMARYObjectives: The aim of this study was to compare the one-year clinical performance of three restorative systems, which included a novel low-shrinkage composite and two bonding strategies.Materials and Methods: Twenty-five patients received three Class I (occlusal) or Class II restorations performed with one of three restorative systems: Filtek Silorane Restorative System (FS); Adper Scotchbond 1 XT, a twostep etch-and-rinse adhesive, with Filtek Z250 (XT); and Adper Scotchbond SE, a two-step self-etch adhesive, with Filtek Z250 (SE). All materials were applied following the manufacturer's instructions. Two independent observers evaluated the restorations at baseline, after six months, and after one year, according to the United States Public Health System modified criteria. The Kruskal-Wallis test and the Mann-Whitney U-test were computed to compare the behavior of the restorative systems; Friedman and Wilcoxon tests were used to analyze the intrasystem data (a=0.05).Results: All restorations were evaluated at one year. FS and XT performed statistically similarly at one year, but marginal staining for SE was statistically worse. Intrasystem comparisons between baseline and one year also showed deterioration of marginal staining for SE, while a deterioration of the marginal adaptation was recorded for both SE and FS. XT was the only system for which there was no

Section: Discussionmentioning

confidence: 99%

Clinical Evaluation of a Low-shrinkage Composite in Posterior Restorations: One-Year Results

Baracco¹,

Perdigão²,

Cabrera³

et al. 2012

“…There have been several attempts to overcome polymerization shrinkage such as using an incremental layering technique, placing a stress-absorbing liner, and changing the light-curing procedures. 1,2 Recently, a silorane-based material was introduced. Silorane composite has shown approximately 0.94 vol% to 1.5 vol% shrinkage [3][4][5] and comparable flexural strength to methacrylate composite.…”

Section: Introductionmentioning

confidence: 99%

Effect of Surface Treatments on Microtensile Bond Strength of Repaired Aged Silorane Resin Composite

Palasuk

Platt

Cho

et al. 2013

SUMMARY Objective: This laboratory study compared the repaired microtensile bond strengths of aged silorane resin composite using different surface treatments and either silorane or methacrylate resin composite. Methods: One hundred eight silorane resin composite blocks (Filtek LS) were fabricated and aged by thermocycling between 8°C and 48°C (5000 cycles). A control (solid resin composite) and four surface treatment groups (no treatment, acid treatment, aluminum oxide sandblasting, and diamond bur abrasion) were tested (N=12 blocks, 108 beams/group). Each treatment group was randomly divided in half and repaired with either silorane resin composite (LS adhesive) or methacrylate resin composite (Filtek Z250/Single Bond Plus). After 24 hours in 37°C distilled water, microtensile bond strength testing was performed using a non-trimming technique. Surface topography after surface treatment was analyzed using scanning electron microscopy (SEM). Failure mode was examined using optical microscopy (50×). Results: Weibull-distribution survival analysis revealed that aluminum oxide sandblasting followed by silorane or methacrylate resin composite and acid treatment with methacrylate resin composite provided insignificant differences from the control (p>0.05). All other groups were significantly lower than the control. Failure was primarily adhesive in all groups. Conclusion: Aluminum oxide sandblasting produced microtensile bond strength not different from the cohesive strength of silorane resin composite. After aluminum oxide sandblasting, aged silorane resin composite can be repaired with either silorane resin composite with LS system adhesive or methacrylate resin composite with methacrylate dental adhesive.

“…Nevertheless, no single method has been totally efficacious in counteracting the effects of polymerization shrinkage. 15 In all the groups, the gap width decreased from the outer part of the cervical margin to the inner part which represents a V-shaped gap formation in composite restorations on root surfaces. It has been reported that this phenomenon occurs because polymerization shrinkage forces are greater than the initial bond strength of composite to root dentin.…”

Section: Discussionmentioning

confidence: 99%

Cervical Margin Integrity of Class II Resin Composite Restorations in Laser- and Bur-Prepared Cavities Using Three Different Adhesive Systems

Oskoee

Kimyai

Ebrahimi³

et al. 2012

Bur-prepared cavities represented less interfacial gap width than laser-prepared cavities. A self-etching adhesive system showed the least interfacial gap compared to etch-and-rinse adhesives and performed similarly in bur-and laser-prepared cavities. SUMMARYOne of the challenges in durability of posterior tooth-colored restorative materials is polymerization shrinkage, which results in gap formation between the restoration and tooth structure. The aim of the present study was to investigate marginal adaptation of Class II composite restorations using a self-etching and two etch-and-rinse adhesive systems in cavities prepared either with bur or Er,-Cr:YSGG laser. A total of 45 extracted sound human premolars were selected. In each tooth, mesial and distal Class II cavities were prepared either by a diamond bur or by Er,-Cr:YSGG laser with the margins 1 mm apical to the cemento-enamel junction. Then the teeth were randomly divided into three groups of 15 each, according to the type of the adhesive system used (Single Bond, Single Bond 2, Parnian Alizadeh Oskoee, DDS, MS, associate professor,