Comparative evaluation of surface roughness and wettability of an alkasite with nano bulk-fill and nanofilled resin composite restorative materials: In vitro study

Context: Surface characteristics of resin-based composites (RBCs) can change with polishing and over time. Aim: The aim of the study was to compare the surface roughness and wettability of three different posterior RBCs after polishing and the change in these surface characteristics over time, after aqueous aging. Settings and Design: Experimental in vitro study. Materials and Methods: Eleven disc-shaped RBC specimens were fabricated. The RBCs used were, alkasite composite, bulk-fill nanocomposite, conventional nanofilled composite. All the specimens underwent polishing with Soflex Diamond Polishing System and then analyzed for roughness and wettability at baseline and after aqueous aging for 3 months with the help of an atomic force microscope and a contact angle goniometer respectively. Statistical Analysis: One-way ANOVA and Tamhane test were used for the multiple comparisons. Results: Alkasite composite showed significantly higher surface roughness (P = 0.028 and P < 0.001, respectively) and lower wettability (P = 0.023 and P = 0.020, respectively) than conventional nanofilled composite at baseline and 3 months. Surface roughness of alkasite composite was also significantly higher than bulk-fill nanocomposite (P = 0.009 and P < 0.001, respectively) at both the time points. Conclusions: Alkasite has higher surface roughness in comparison to conventional nanocomposite and bulk-fill nanocomposite and lower wettability than conventional nanocomposite after polishing and aqueous aging over a 3-month period. In terms of surface characteristics, alkasite composite may be advantageous in preventing initial plaque adhesion to the material surface, but the lower surface roughness of nano-filled composites may be more advantageous in terms of plaque retention prevention.