Effect of Curing Time on Bond Failurerct Based on Two Light Cure Units used in Bonding Orthodontic Brackets

In routine orthodontic practice, we usually aim at having a reduced chair side time while bonding as well as an appropriate bond strength for the brackets till the treatment completion. This is dependent on several factors which affect the quality of bond obtained between the bracket and the tooth structure. One such is the depth of cure by using different curing lamps. This study aimed at comparing the rate of bracket bond failure of brackets when bonded using light cure units with different curing time (3S and 20S). This was a randomized control trial performed as a split mouth study among patients who came for orthodontic correction of malocclusion. Among them, 24 patients were selected and split mouth study was performed. For this dental arch of each patient was split among two groups (Group A and Group B). MBT Stainless steel orthodontic brackets were bonded in both the dental arches. Group A was cured with 3 second light cure unit in I and III quadrant and 20 second light cure unit in I and III quadrant and vice versa for group B. The number of bond failures at the end of 4 weeks and 8 weeks were assessed. Bond failures among both the groups were summarized. Independent t test was used to assess the statistical difference between the groups. Overall it was evident that the bond failure was greater clinically in the group cured with 20 second curing light especially in the mandibular arch and the posterior teeth.