Evaluation of the Effect of Water on the Flexural and Shear Strength of Silorane and Methacrylate-based Composites; A Review of Long-term Studies.

Objective: Due to the importance of the effect of water on the structure of composites, in the present systematic review, the effect of water on the flexural and shear strength of silorane and methacrylate-based composites was investigated. Method: Research articles published in English and Farsi were searched using the relevant terms in PubMed, Web of Science Core, POPLINE, EMBASE, Scopus, CINAHL, PsycINFO, International Bibliography of Social Science, and DoPHER databases. In the initial search, 2345 records were obtained. At the next stage, 1482 records were deleted due to duplication, and all articles that did not meet the inclusion criteria or were inappropriate due to indirect relevance to the topic (739 records) were removed. Then, the full-text of 124 articles was reviewed. Finally, 7 studies that met all inclusion criteria were selected for this review study. Results: Based on the inclusion criteria, 7 studies were selected and examined in more detail. In 3 papers, only one composite (methacrylatebased) was investigated. In all but one of these studies, following water uptake over time, a reduction in the shear or flexural strength of the composites was reported. In four other articles, the effect of water on shear or flexural strength in both types of silorane and methacrylate-based composites was investigated. Examination of the results of these papers showed that although they indicated a reduction in mechanical forces for both composites, the rate of reduction was higher for methacrylate-based composites compared to silorane-based composites. Conclusion: Although there was a decrease in shear or flexural strength of both types of composites, silorane-based composites demonstrated a lower rate of reduction in these forces compared to methacrylate-based composites. Therefore, it can be concluded that following water absorption, the mechanical properties of silorane-base composites change less than methacrylate-based composites. [ABSTRACT FROM AUTHOR]