Bond Strength of Different Dentin Bonding Systems to Fluorosed Enamel

Objective: The shear bond strength of three different bonding strategies on fluorosed enamel surfaces was investigated.

Methods: Thirty six non-carious extracted human molar teeth with fluorosis and 36 without fluorosis were scraped clean from any tissues left, and then were divided into three subgroups according to the tested bonding systems. The resin composite Z250 (3M ESPE) was bonded to the teeth using three different dentin bonding systems: Peak LC Bond with total- etch technique (Ultradent Products, Inc), Peak LC Bond with self-etch technique using Peak SE Primer (Ultradent Products, Inc) and a one bottle self-etch system Xeno V (Densply DeTrey). Following the photopolymerization of the resin composites, thermocycling was performed 5000 times. The shear bond strengths were tested using a Shimadzu Universal Testing Machine until failure. The analysis of the fractured enamel surfaces was performed using an Optical Microscope-Nikon ECLIPSE ME 600 at x10 and x1000 magnifications and the images were analyzed with Image Analyzer LUCIA 4.21. The data were analyzed with two-way ANOVA and Tukey test at a significance level of p<0.05.

Results: Mean shear bond strength data of the groups in MPa were: Peak LC Bond with total-etch technique on fluorosed enamel: 16.77±2.32 and on non-fluorosed enamel: 21.13±2.74; Peak LC bond with self- etch technique on fluorosed enamel: 13.23±2.58 and on non-fluorosed enamel: 17.81±2.90; one-bottle self-etch system Xeno V on fluorosed enamel: 10.79±2.14 and on non-fluorosed enamel: 14.58±2.99.

Conclusion: The use of a total-etch dentin bonding system produced higher bond strengths of the resin composite tested to fluorosed and non-fluorosed enamel than both self-etch bonding systems. Fluorosis did adversely affect the bonding performance of the adhesive systems to the enamel.

The adhesives tested in this study were generously donated by their respective manufacturers.