To Compare and Evaluate The Efficacy and Effect on Dimensional Accuracy of the Different Disinfection Techniques on Polyvinyl Siloxane Impression Material When Exposed To Commonly Occurring Oral Micro Flora

Abstract Aim: The purpose of this in vitro study was to compare and evaluate the efficacy and effect on dimensional accuracy of the different disinfection techniques on polyvinyl siloxane impression material when exposed to commonly occurring oral micro flora. Materials And Methods: The impressions were divided into five groups (fifteen samples per group) and subjected to a spray disinfection with 2% glutaraldehyde (Group I), UV light (Group II), freshly prepared electrolyzed oxidizing water (EOW) with different pH values - acidic (Group III a), alkali (Group III B) and neutral (Group III C).The samples were examined pre and post-immersion under 2x magnification for surface detail reproduction, stereovision microscope for measurement of dimensional stability and surface profilometer for evaluation of surface texture. A standardized master die was fabricated and seventy-five PVS test samples were made. The samples were subjected to immersion disinfection and studied for surface detail reproduction, dimensional stability and surface texture. Post hoc test and ANOVA were used to analyze dimensional stability statistically both within and between the test groups. Results: The surface detail reproduction was satisfactory with both pre and post-immersion test samples. A statistically significant difference was observed on inter group comparison in group II and group III C whereas group III, group III B and groupI showed non significant dimensional changes. There was a negligible change in surface roughness post-immersion in Groups I, III a, III b, III c test samples with a slight increase in surface roughness post-immersion in Group I samples. All disinfectants showed statistically significant values for efficacy with highest 4log10 reduction in gluteraldehyde. Conclusion: In this study, all the test disinfectants produced satisfactory surface detail reproduction on PVS impressions. Except UV light and electrolysed water neutral which showed statistically significant dimensional changes others disinfectants showed non significant changes on polyvinyl silixone impression material surface. All the samples showed decrease in surface roughness except the surface disinfected with gluteraldehyde which increased the surface roughness values. Statistically significant values of efficacy was observed for all five disinfecting agent i.e gluteraldehyde, UV light and electrolysed water acidic, electrolysed water basic, electrolysed water neutral. Gluteraldehyde showed highest efficacy and electrolysed water neutral showed lowest amount on comparison within these 5 disinfecting agent.