Thermal Aging-Induced Alterations in Surface and Interface Topography of Bio-Interactive Dental Restorative Materials Assessed by 3D Non-Contact Profilometry

This study aimed to evaluate the effects of thermal cycling and restorative material type on surface roughness of material surfaces and dental interfaces using a non-contact profilometer. Ninety Class V cavities (2 mm × 4 mm × 2 mm in height, width, and depth) were prepared on extracted third molars and restored with four bio-interactive materials (Equia Forte, Cention-N, Activa BioActive Restorative, Fuji II LC) and one composite resin (Solare-X) (n = 18/group). After polishing (Optidisc), initial surface roughness (Sa, µm) was measured following 24 h immersion in distilled water. Measurements were performed at cement/material (400 × 1600 μm2), enamel/material (1600 × 400 μm2), and material surfaces (800 × 800 μm2). Samples underwent 10,000 thermal cycles (5–55 °C) to simulate aging, and roughness was re-measured. Data were analyzed with two-way repeated measures ANOVA and Tukey’s post hoc test (p < 0.05). Solare-X showed the lowest roughness, while Fuji II LC and Activa BioActive Restorative were smoother than Cention-N and Equia Forte (p < 0.01). All materials exhibited significant roughness increases after thermal cycling (p < 0.01). Cement/material and enamel/material interfaces consistently showed higher roughness than material surfaces (p < 0.01). Thermal cycling significantly increased surface roughness of all tested materials. Interfaces demonstrated greater roughness than material surfaces, indicating higher susceptibility to plaque retention and potential risk for long-term restoration success.