INFLUENCE OF COMPOSITE RESTORATIVE MATERIALS COMPOSITION ON

Purpose: To evaluate and compare the diametral tensile strength (DTS) values of the newly introduced nanofilled composites with the conventional types.Methods: Eight types of dental restorative composites of A3 shade were selected in this study for (DTS) testing: Filtek Supreme XT (3M Espe), Z100 Restorative (3M Espe), Filtek P60 (3M Espe), Filtek Z250 (3M Espe), Premise (Kerr), Point 4(Kerr), Herculite classic (Kerr), and Solitaire (Heraeus-Kulzer). Eight groups of specimens (n = 10) were prepared for diametral tensile strength evaluation. Resin composite specimens were prepared by incremental (two increments) insertion of composite into a circular nickel-chromium split mold of 6 mm in inner diameter and 3 mm in height and cured for 40 seconds for each increment of composite thickness. Specimens were placed into a dark bottle containing distilled water at 37°C for 7 days. DTS tests were performed in a Universal Testing Machine (0.5 mm/min).Results: The results showed that the highest DTS values were found for the Premise composite followed by Point 4, Herculite, Solitaire, Z250, Supreme XT, P60 and Z100 which exhibited the lowest DTS values.Conclusion: The composition of light activated composites is significantly influences their DTS values.