ABSTRACT
OBJECTIVE: To assess the influence of laser-textured surfaces on the adhesion of composite to dentin after being rotary prepared. METHODS: Thirty healthy teeth were kept in 0.1% thymol solution prior to being ground down to dentin to create a 4 × 4 mm² flat surface. Teeth were divided into 3 groups (n=10). Groups 1 and 2 utilized the prototype Erbium doped, Yttrium-Aluminum-Garnet Er:YAG laser by Dental Photonics, Inc. A single pulse was delivered to each spot to create an equally spaced square 4 × 4 mm² matrix of micro craters. All craters had 100 µm diameter/45 µm depth; two different spacing patterns were prepared in Groups 1 and 2. In Group 1, distance between crater centers was 50 µm; Group 2 had 100 µm. In Group 3 (control), 10 samples were prepared without laser texturing. G-bond (GC America) was applied to testing area of all samples in all groups according to manufacturer's instructions. Bonding resin was applied and shear-bond strength tests were employed using an Instron machine to measure adhesive strength. RESULTS: One-way analysis of variance (ANOVA) was used to compare the 3 groups. Pair wise t-tests implementing the Bonferroni correction for multiple comparisons found a statistically significant difference between Group 3 and Group 2 (p=0.019) but no statistically significant difference between Group 3 and Group 1 (p=0.263) or Group 1 and Group 2 (p=0.743). SIGNIFICANCE: The bond strengths between bonded composite to laser-textured dentinal surfaces with larger spacing patterns are greater than that of non-textured surfaces.
