Effect of fractionated therapeutic radiotherapy on surface microhardness and roughness of giomer- and ormocer-based restorative composites: an in vitro study
摘要
The influence of therapeutic radiation on the surface properties of contemporary restorative materials remains an important area of investigation. This study aimed to assess the effect of therapeutic radiation on the microhardness and surface roughness of two restorative materials, as these properties are associated with restoration durability. Ninety-six discs were fabricated from Giomer and Ormocer resin composites (n = 48 per material). Specimens were randomly allocated to two subgroups: surface microhardness (MH) and roughness (Ra), based on the tests performed (n = 24). For each test, specimens were further subdivided into two subgroups (n = 12). IR0: control, no irradiation; IR1: irradiated, exposed to a total of 70 Gy over 35 days (2 Gy/day, 5 days/week) using a linear accelerator (10 MV photons, 2 Gy/fraction). MH was measured using a 100 g load for 15 s, and Ra was evaluated using a non-contact digital microscopy method and analyzed with WSxM software. Data were analyzed using two-way ANOVA, with significance set at p < 0.05. No significant differences were detected between control and irradiated specimens in either microhardness or surface roughness (p > 0.05). Both restorative materials demonstrated stable surface microhardness and roughness, following exposure to a clinically relevant radiotherapy protocol.