Year : 2016

Volume : Volume 6

Issue : Issue 2s

Address for correspondence :
Dr. Hema Chandrika I
inguvahemachandrika@gmail.com

Abstract

Aim: Various concentrations of carbamide peroxide are being used as both office and at-home bleaching agents. The present study was carried out to evaluate the effects of these agents on the surface microhardness of sound human enamel. Materials & Methods: 25 sound premolars extracted for orthodontic purposes were sectioned, windows were made on buccal and lingual surfaces and were divided into five groups:  Group I- Control group exposed to artificial saliva; Group II- exposed to 10% carbamide peroxide gel for 6 hours daily; Group III- exposed to 15% carbamide peroxide gel for 4 hours daily ; Group IV- exposed to 20% carbamide peroxide gel for 2 hours daily; and Group V- exposed to 35% carbamide peroxide gel for 30 minutes daily as per the manufacturer`s recommendations for a period of 1 week. Microhardness test was then carried out on all the specimens using a Vicker`s Diamond indentor using a load of 100g for a period of 12 seconds per indentation. Three indentations were made for each specimen to get the average microhardness values..the results were then subjected to statistical analysis. Results:  Bleaching procedures with 10% gels showed no major decrease in microhardness; while those with higher concentrations showed significant reductions in enamel microhardness compared to control group. 20% and 35% gels showed a highly significant reduction in microhardness values. Conclusion: This study has shown that all bleaching agents caused a reduction in enamel microhardness. This reduction was significant when higher concentrations of bleaching agents were used.

Keywords: Bleaching, Carbamide Peroxide, microhardness.