EFFECT OF VARIOUS FLUORIDE VARNISH ON BRACKET SHEAR BOND STRENGTH: INVITRO STUDY.

Aim:- The present study has been taken-up to evaluate the effect of topical fluoride varnish application on enamel surface and the effect of the same on the shear strength of orthodontic bracket bonding. Methods:- 120 extracted premolar teeth without any decay or visible defect were collected from the Department of Oral and Maxillofacial surgery, Farooqia Dental College and Hospital, Mysore Karnataka. These 120 orthodontic bracket bonded to premolars were subjected to the shear bond strength. The teeth were divided into control group, Duraphat varnish group, Varnish 3M group, ClearShieldTM group. The samples were tested on day 1, 8 and15. The samples were coated with their respective varnish, followed by bonding of brackets using ENLIGHT light cure adhesive system. Each specimen was subjected to shear force on universal testing machine until the bracket gets deboned and the same of 120 specimens were subjected to Adhesive Remnant Index test. The whole data was analysed using ANOVA analysis. Results:- At day 1 the mean shear bond strength of ClearShieldTM group has shown a significant difference from other groups. Whereas at day 8 and 15 Duraphat varnish group had significantly higher range of shear bond strength. The shear bond strength in comparison to all groups in all days has shown no significance. ARI scores for the same specimens, has no significant difference in mean in between the groups. Conclusion:- The application of fluoride varnish, irrespective of the time interval between fluoride treatment and bonding procedure, does not affect the shear bond strength. Adhesive Remnant Index test has shown no significance in all groups.