The effects of various surface treatments on enamel surfaces have demonstrated decreased bond strengths of composite to enamel. The objective of this study was to evaluate the effect of smokeless tobacco on the shear bond strength of resin composite to enamel. Sixty recently extracted human molar teeth were collected, mounted in stone cylinders, then randomly divided into two groups of 30 teeth each. The first group was stored in human saliva until testing. The second group was stored in a solution of saliva and smokeless tobacco for 30 days. Each group was further divided into two subgroups of 15 teeth each where one group would receive a fluoride-free, pumice prophylaxis just prior to bonding. Specimens were acid-etched with 37% phosphoric acid, rinsed, and air-dried. Scotchbond Multipurpose was applied to enamel surfaces following manufacturer's directions. Composite cylinders 3mm in diameter were bonded to enamel surfaces. Specimens were stored in water for 24 hrs then loaded in an Instron Universal Testing Machine with a crosshead speed of 0.5 mm/min until failure. Data were subjected to a two-way ANOVA at alpha=0.05. Mean bond strength in MPa for the control group w/o pumice was 44.1 ± 5.8; control with pumice, 47.5 ± 9.8; tobacco w/o pumice, 39.1 ± 10.9; tobacco with pumice, 44.6 ± 11.1. There was no evidence to suggest a difference among experimental groups testing the main effects of tobacco (p=0.12) or pumice (p=0.08). While it is prudent to clean surfaces prior to bonding, the results of this study suggest that smokeless tobacco does not appear to be a significant contaminant interfering with composite bond strength.

Back to the Dental Materials: I - Adhesion-Composite Bond Strength Program
Back to the IADR/AADR/CADR 80th General Session (March 6-9, 2002)

Top Level Search