Effect of immediate and delayed finishing and polishing on the surface roughness and microhardness of alkasite and giomer

Finishing and polishing (F/P) procedures are essential for optimizing resin-based restoration esthetics, wear resistance, and surface quality. Bioactive materials like Alkasite and Giomer have attracted attention for their potential clinical benefits, although limited evidence exists regarding the impact of immediate versus delayed F/P protocols on their surface properties. This study assessed how F/P timing and systems influence the surface roughness and microhardness of these materials.One hundred cylindrical specimens (n=50 per material) were prepared and divided into five subgroups: control (Mylar strip), immediate Sof-Lex, delayed Sof-Lex, immediate Politip, and delayed Politip. Surface roughness was measured using a profilometer, surface morphology was examined with SEM, and microhardness was tested with a Vickers hardness testing. Two-way ANOVA and Tukey's post hoc test were used to analyze the data (p < 0.05).Control groups exhibited the smoothest surfaces, with Giomer showing significantly lower roughness values than Alkasite across all subgroups. In Giomer, Sof-Lex produced the lowest Ra values, while Alkasite showed no significant differences between protocols. Microhardness results revealed no significant variation between materials regardless of F/P system or timing.The timing of F/P procedures did not significantly affect the surface roughness or microhardness of Alkasite or Giomer.