Effects of adhesion promoter on orthodontic bonding in fluorosed teeth: A scanning electron microscopy study.

INTRODUCTION: The objectives of the present study were to elucidate the effects of fluorosis in orthodontic bonding and to evaluate the efficiency of an adhesion promoter (Assure Universal Bonding Resin) in bonding to fluorosed teeth.

MATERIALS AND METHODS: Extracted premolars were divided into two groups on the basis of Thylstrup and Fejerskov Index. Ten samples from each group were etched and evaluated for etching patterns using scanning electron microscope (SEM). The remaining samples were subdivided into four groups of 20 each on the basis of adhesives used: IA, IIA - Transbond XT and IB, IIB - Transbond XT plus Assure Universal Bonding Resin. Shear bond strength (SBS) was measured after 24 h using the universal testing machine. Adhesive remnant index (ARI) scores were recorded using SEM. Statistical analysis was conducted using a two-way analysis of variance, and Tukey's post hoc test was performed on SBS and ARI scores.

RESULTS: Similar etching patterns were observed in both fluorosed and nonfluorosed teeth. No significant differences were found in the SBS values observed in both groups (8.66 ± 3.19 vs. 8.53 ± 3.44, P = 1.000). Increase in SBS was observed when Assure Universal Bonding Resin was used. Higher ARI scores were observed when adhesion promoter was used for bonding.

CONCLUSIONS: Mild-moderately fluorosed teeth etch in a manner similar to the nonfluorosed teeth. Similar bond strengths were achieved in fluorosed and nonfluorosed teeth when conventional composite was used. Use of adhesion promoter increases the bond strengths in both groups of teeth.