The Effect of Dimethacrylate Monomer Ratio on the Curing Profile of Dental Composites: A Thermal, Kinetic, and Comparative Analysis

This study investigates the thermal curing behavior of matrices formulated with varying ratios of dimethacrylate monomers commonly used in dental composites. Thermal analysis techniques were employed to characterize the curing profiles and identify how monomer composition influences activation energy, reactivity, and network development. Unlike previous studies that focus on light‐curing behavior, this work provides a systematic comparative evaluation of the thermal curing kinetics of methacrylate‐based matrices with controlled filler content. Matrix formulations (M1, M2, M3) and their corresponding composites (MK1, MK2, MK3) were produced. For flexural strength testing, specimens were prepared for each composite ( n = 5) and tested according to BS EN ISO 4049. Curing behavior was evaluated in terms of reaction characteristics, onset and completion temperatures, degree of conversion. Systems with higher UDMA content cured more rapidly at lower temperatures, exhibiting sharp and high‐energy exothermic peaks. In contrast, formulations with higher BISEMA3 content showed delayed polymerization yet better thermal stability due to the rigidity of the aromatic structure. Kinetic parameters obtained using the Kissinger and Flynn–Wall–Ozawa methods revealed significant variations in activation energy and isoconversion behavior depending on monomer ratio. The influence of heating rate on polymerization kinetics was further demonstrated through kinetic plots.