Advisory Committee Chair
Chin C Fu
Advisory Committee Members
Date of Award
Degree Name by School
Master of Dentistry (MDent) School of Dentistry
INTRODUCTION: Candida albicans has been regarded as the most predominant oral fungal pathogen and the main causative of denture stomatitis. Modern denture are fabricated from various types of polymers commonly: CAD/CAM or heat-cured. C. albicans adherence rate to these polymers and disinfection efficacy of adherent fungal biofilms are multifactorial processes and differ depending on the physical characteristics of the targeted surface. PURPOSE: The purpose of this study was to investigate Candida albicans adherence to specimens from three types of polymers namely: heat-cured PMMA, CAD/CAM milled and 3D printed. The second part compares the efficacy of four common disinfection techniques on the same types of polymers: glutaraldehyde, brushing, microwave irradiation and Polident® overnight tablets. METHODS: Eighty blocks of pink acrylic specimens were fabricated from each polymer group. For the first part, 10 specimens were placed in yeast assay and incubated for 90 min while 10 other specimens served as negative controls. For the second part, 60 specimens from each type were used (10 negative and 50 placed in a yeast assay and incubated overnight). Out of the 50 specimens, 10 disinfected with 2.5% glutaraldehyde, 10 with mechanical brushing, 10 with microwave irradiation, and 10 with tablets. Two-way II ANOVA and Tukey multiple comparisons test were used to analyze both optical density readings and the number of fungal colonies scanned in agar plates. RESULTS: Significant differences in C. albicans adherence to the three polymers were noted. CAD/CAM milled had the best results followed by 3D printed and last came heat-cured PMMA with high significance. However, when specimens were incubated overnight, CAD/CAM milled maintained the best results followed by conventional PMMA and 3D printed came last with significantly high numbers. In the disinfection test, microwave irradiation, mechanical brushing and tablets showed insignificant differences for all three polymers whereas glutaraldehyde came last with significantly higher results. CONCLUSION: Candida albicans adherence to the polymers varied greatly and the porosity-free surface gave a competitive advantage to CAD/ CAM milled throughout the entire study. Heat-cured PMMA and 3D printed had higher fungal biofilms attachment that translates into higher DS vulnerability. In disinfection techniques, microwave irradiation results were pristine with complete disinfection achieved in conventional PMMA. Mechanical brushing and Polident® overnight tablets had close results while glutaraldehyde was not as effective. The results of this study show that CAD/ CAM milled has superior characteristics with lower fungal affinity and great results with most modern disinfection techniques.
Koujan, Mohammad Amir, "In Vitro Evaluation of Candida albicans Adherence and Disinfection Techniques on CAD/CAM Milled, 3D Printed, and Heat-Cured PMMA" (2020). All ETDs from UAB. 2182.