EFFECT OF DISINFECTANTS ON FLEXURE STRENGTH AND SURFACE ROUGHNESS OF 3D-PRINTED VERSUS CONVENTIONAL DENTURE BASE RESINS (A COMPARATIVE IN-VITRO STUDY)

Introduction: Computer aided design-computer aided manufacturing (CAD-CAM) additive technique (three-dimensional printing) (3D-printing) is widely used nowadays for fabrication of denture bases. Various disinfectants should be assessed for their effect on flexural strength (FS), Modulus of elasticity (EM) and surface roughness (Ra) of 3D-printed and conventional denture base resins.Aim of the study: The purpose of this in-vitro study was to evaluate the effect of denture disinfectants on FS, EM, and Ra of 3D-printed versus conventional denture base resins.Materials and Methods: Evaluation of FS, EM and Ra of conventional (Group I) and 3D-printed denture base resins (Group II), was carried out before and after immersion of overall 176 specimens, 88 specimens from each group into 3 different types of disinfectants and one control group (distilled water) (DW). FS and EM (MPa) (N=80) were measured using universal testing machine and 3-point bending test. Ra (μm) (N=96) was evaluated using contact profilometer and confirmed with scanning electron microscope (SEM) at magnification of x1500. Results: Significant reduction in FS and EM, beside significant increase in Ra of both groups after immersion into 1% sodium hypochlorite (1% NaOCl), and 2% Chlorhexidine gluconate (2% CHX). Insignificant reduction in FS and EM of both groups with 100% White Vinegar (100% WV).Conclusion: All disinfectants reduced FS and EM and raised Ra. 100% White vinegar showed the least adverse effect on FS, EM and Ra of both groups compared to other disinfectants, while 1% NaOCl showed the most harmful effect.