Abdullah A. Abonema, Ihab E. Mosleh And Hanaa H. Zaghloul,
ABSTRACT
Statement Of Problem: Surface Finishing And Polishing Techniques Have A Mechanical Impact On Ceramic - Polymer Surfaces That Can Eventually Affect The Surface Roughness And Color. Expected Changes, After Being Subjected To Aging Procedures, Necessitates Adopting A Finishing And Polishing Protocol To Enhance Their Impaired Optical Properties. The Purpose Of This In Vitro Study Was To Assess The Effect Of Two Different Polishing Techniques On The Surface Roughness And Color Stability Of Two CAD/CAM Ceramic-polymer Materials Compared To CAD/CAM Glass Ceramic Material Before And After Being Subjected To Chemical And Mechanical Aging Procedures.
Materials and Methods: Fourty-two Discs Were Constructed From CADCAM Esthetic Blocks. Lithium Disilicate CAD/CAM Glass Ceramics As Control (n=14), Ceramic-polymer Hybrid Materials, Lava Ultimate (n=14) And Vita Enamic (n=14) Were Studied. Discs In Each Group Were Divided Into Equal Subgroups (n=7) According To The Polishing Technique Employed. One Subgroup Was Polished Following The Manufacturer?s Recommendations (mnf) And The Other Was Polished By Brush And Paste Protocol(B/P). Mechanical And Chemical Aging Procedures Were Performed For Each Subgroup. The Surface Roughness And Color Of Each Specimen Were Measured Before And After All Interventions And Aging Procedures. Surface Topography (Ra) Was Evaluated Using Contact Stylus Profilometer And The Average Ra Values (?m) Were Calculated. Laboratory UV Spectrophotometer Was Used To Measure Color Parameters (a*,b*,L*). Color Differences (??) And Surface Roughness (Ra) Data Were Analysed Using Two-way (ANOVA).
Results: There Was No Significant Difference In Surface Roughness Values Between The Two Techniques After Polishing. After Mechanical Aging, (mnf) Technique Showed Significantly Higher Surface Roughness Than (B/P) Except For Vita Enamic. After Chemical Aging, The Two Polishing Techniques Showed No Significant Difference In Mean Color Change (?E) Values With All Ceramic Types.
Conclusion: The Brush/paste Polishing Protocol Produced Comparable Surface Smoothness To The Manufacturer?s Protocol For Glass And Polymer Ceramics. Color Change Is Material Compositional Microstructure Dependent.
