Monomer conversion degree of preheated Bis‑GMA free and containing resin composite

Concerns have arisen regarding the use of bisphenol-A glycidyl methacrylate (BisGMA), a derivative of bisphenol A (BPA), in the field of dentistry. This study aims to assess how varying preheating temperatures of bulk-fill resin composites, which differ in monomer content, influence the degree of monomer conversion (DC). The composites included Bis-GMA-containing methacrylate monomer and Bis-GMA-free resin composites with poly-siloxane monomer. Sixty resin composite specimens were formulated, thirty from each tested bulk-fill resin composite material; Bis-GMA free (Admira Fusion X-tra) and Bis-GMA containing (Viscalor). Each group was subsequently subdivided into three subgroups (n = 10) depending upon the tested preheating temperature (54 °C and 70 °C) in comparison to room temperature (23 °C) (control group). The degree of conversion (DC) was evaluated before and immediately after curing utilizing Fourier transform infrared spectroscopy (FTIR). The independent t-test was used to evaluate various testing materials and heating temperatures comparatively. A two-way ANOVA was utilized to appraise the data. The significant level was adjusted at p = 0.05. The mean value of (DC %) of both tested resin composites was determined to be highest at 70 °C and lowest at room temperature 23 °C. At room temperature, a statistically significant difference in the DC among both inspected materials was found, where the Bis-GMA free was significantly higher than containing, while no significant difference among them at 54 °C and 70 °C. Preheating resin composite promotes the DC of both investigated resin composites irrespective of the monomer content.