Mechanical Property Assessment of Polyacid-Modified Composite Resins: An In Vitro Approach

This in vitro study performed a comparative mechanical evaluation of three classes of direct restorative materials: resin composites, polyacid-modified composite resins (components), and Glass Ionomer Cements (GICs).The objective was to clarify the mechanical position of components relative to composites and glass ionomer cements (GICs).Specimens from two materials per class including the components Dyract AP and Dyract Extra were fabricated using standardized molds.Compressive, diametral tensile, and three-point flexural strength tests were conducted according to ADA and ISO specifications, followed by statistical analysis using ANOVA and Tukey's HSD test.Results established a consistent mechanical hierarchy: composite resins exhibited the highest strength values in all tests, followed by components, with GICs demonstrating the lowest.Within the component group, the thirdgeneration Dyract Extra showed superior properties compared to Dyract AP.The findings confirm that components occupy an intermediate mechanical position, offering significantly greater strength than GICs but not matching composites.Thus, components suit low-to-moderate stress applications where fluoride release and handling ease are beneficial, while composites remain indicated for high-stress areas.This study provides clear evidence for evidence-based clinical material selection.