Triclosan/copolymer/NAF dentifrice prophylaxis, reduced etching time and shear bond strength of a resin composite to enamel.

This study evaluated the effect of a prophylaxis with a triclosan/copolymer/NaF dentifrice (Colgate Gum Protection Formula) and a reduced etching time with 37% phosphoric acid gel on the shear bond strength of a resin composite to enamel. 60 human extracted permanent molars were used. A flat enamel surface was obtained with 600 grit SiC paper and cleaned with a rubber cup and a water slurry of fine flour of pumice. The teeth were randomly distributed into 4 groups of 15 teeth each: Group 1: Pumice prophylaxis with a rubber cup, etched for 30 seconds; Group 2: Pumice prophylaxis, etched for 60 seconds; Group 3: Triclosan/copolymer/NaF dentifrice prophylaxis, etched for 30 seconds; Group 4: Triclosan/copolymer/NaF dentifrice prophylaxis, etched for 60 seconds. After etching, rinsing and drying, an unfilled resin (Coe Bond) was thinly applied with a brush and cured for 30 seconds. A nylon ring was placed over the area and filled with a light-cured resin composite (Occlusin). The teeth were thermocycled for 500 cycles and sheared with a knife-edged blade in an Instron running at a crosshead speed of 1 mm/min. The results in MPa were as follows: Group 1: 18.84 +/- 7.08; Group 2: 22.65 +/- 4.37; Group 3: 18.79 +/- 5.77; Group 4: 19.62 +/- 6.13. An ANOVA showed that there was no statistically significant difference among the groups. Enamel fracture occurred in 20% (3/15) in Group 1, 53% (8/15) in Group 2, 20% (3/15) in Group 3, and 47% (7/15) in Group 4.(ABSTRACT TRUNCATED AT 250 WORDS)