Shear bond strength of laser cured composite resin for direct bonding of orthodontic brackets-an in vitro comparitive study

The aim of the study was to evaluate and compare the clinical performance of two color changing bracket bonding adhesives (Transbond Plus and Grengloo), in terms of bond failure rate, bonding time and time taken by the adhesives to change color.

Eight consecutive patients seeking orthodontic fixed appliance therapy were bonded using Cross arch Split mouth technique, which involves the placement of two varieties of bracket bonding adhesives in diagonally opposite quadrants and cured using a visible light curing unit. The time taken by the adhesive to change color during bonding and the bonding time was noted using a stop watch. The bond failure rates of both the adhesives were evaluated by a thorough follow up of individual case, as and when they reported to the department with a debonded bracket. The data collected were subjected to statistical analysis using Chi square test and student's t-test.

The overall bond failure rate for two color changing adhesives were 7.1% and 8.6%,bonding time was 59.1 and 57.4 seconds per tooth and time to change color was 45.9 and 46 seconds.

There were no significant differences between the failure rates, bonding time and time taken by both the adhesives to change color showing that both are clinically efficient and effective. Clinically they are preferred over the non color changing bracket bonding adhesives as these materials save clinical chairside time because of their color changing property which helps in easy flash removal while bonding brackets.