Thermal-induced polymerization shrinkage in silorane versus methacrylate based resin composite
Shrinkage is a limitation of resin composite, compromising the clinical longevity of the restorative procedure. In an attempt to reduce their harmful effects, researchers have studied monomers with lower values of contraction. As a result, low-shrinkage composites were developed. This study evaluated quantitatively the shrinkage as a function of power density increase based on methacrylates, comparing them with silorane based resin, and qualitatively regarding gap formation between the adhesive interface as function of tooth substrate. Resin Filtek P90 and Filtek Z250 were polymerized with the device Blue Star 3 with 200, 400, 600, 800 and 1000 mW/cm2 keeping volume constant in 12 mm3. For qualitative analysis of restorative interface, class V cavity preparations in bovine incisors were restored in (2x2x2 mm3), photoactivated with the same values of irradiance, and analyzed by scanning electron microscopy at the interface of the wall surrounding enamel, dentin and axial. The quantitative results of the polymerization shrinkage were analyzed by two-way ANOVA and Tukey's test (p<0.05), while qualitative data were submitedd to Mann-Whitney's, Kruskal-Wallis' and Miller's tests. The progressive increase in power density directly influenced the polymerization shrinkage of the materials studied, although the silorane based resin demonstrated significantly lower values. The marginal integrity was influenced by the dental substrate and the power density used.
The Bioscience Journal uses the Creative Commons (CC) license, thus preserving the integrity of the articles in an open-access environment and ensuring the rights of the authors:
- The publication reserves the right to make normative, spelling, and grammar changes in the original documents to maintain a refined standard language but respecting the style of the authors;
- The original documents will not be returned to the authors;
- The authors hold all the rights to their work published in the Bioscience Journal and their full or partial reprint. Deposit or republication is subject to the express authorization from the editor of the journal, fomented through the CC-BY license;
- The original source of publication should be acknowledged;
- The opinions expressed by the authors of the articles are their sole responsibility.