ABSTRACT
PURPOSE: To assess the effect of the erbium:yttrium aluminum garnet (Er:YAG) laser on bond strength of a total-etch adhesive system to the caries-affected dentin on the gingival wall. MATERIALS AND METHODS: Ten human molars with proximal carious lesions were randomly divided into two groups. In the first group, the carious dentin was removed with a bur, whereas in the second group it was removed with the Er:YAG laser. Carious lesions were excavated with one of these two techniques until laser fluorescence values decreased to 15 in the center of the lesions. The teeth were then restored with a total-etch adhesive system (Adper Single Bond 2) and composite resin (Filtek Z250). Five teeth from each group were sectioned to obtain 1 mm2 stick-shaped microtensile specimens from each tooth. Twenty-five specimens were obtained for each group with using this technique. The data were analyzed in independent-samples t-test (α = 0.05). For each removal technique, one sample was analyzed using scanning electron microscopy. RESULTS: No statistically significant differences were found between the bond strength of the Er:YAG laser and the bur-treated groups (P > 0.05). CONCLUSION: The Er:YAG laser treatment did not negatively affect the bonding performance of the total-etch adhesive system to caries-affected dentin on the gingival wall.
Subject(s)
Composite Resins/chemistry , Dental Cavity Preparation/methods , Dental Cements/chemistry , Dental Etching/methods , Lasers, Solid-State/therapeutic use , Composite Resins/therapeutic use , Dental Caries/therapy , Dental Cavity Preparation/instrumentation , Dental Cements/therapeutic use , Dental Etching/instrumentation , Dental Restoration, Permanent , Dentin/chemistry , Dentin/ultrastructure , Humans , Microscopy, Electron, Scanning , Molar , Random Allocation , Tensile StrengthABSTRACT
OBJECTIVE: This study investigated the effect of a re-wetting agent on the microtensile bond strengths (mTBS) of primary and permanent dentin after acid or laser etching. MATERIALS AND METHODS: Twelve permanent and 12 primary molar teeth were ground to expose an occlusal dentin surface. Each group teeth were randomly divided into groups; I-II: 37% phosphoric acid etching with/without re-wetting agent, III-IV: Erbium: Yttrium aluminium garnet laser etching with/without re-wetting agent. An etch-and-rinse adhesive was used, and vertical sticks were obtained for the microtensile test. RESULTS: mTBS of permanent teeth was higher than that of primary teeth (P < 0.05). Re-wetting agent groups were similar with control groups in both etching groups in the permanent teeth (P > 0.05). Re-wetting agent group was similar with the control group in acid etch group (P > 0.05) and lower than the control group in laser etch group in primary teeth (P < 0.05). CONCLUSION: Acid etching in permanent teeth; laser etching in primary teeth was found more successful. The use of re-wetting agent did not provide an advance on bond strength of the adhesive in both primary and permanent teeth after acid-etch or laser-etch.
Subject(s)
Acid Etching, Dental/methods , Dentin-Bonding Agents/chemistry , Wetting Agents/chemistry , Dentin/chemistry , Humans , Molar/chemistryABSTRACT
PURPOSE: This study evaluated the effect of four resin materials on the shear bond strength (SBS) of a ceramic core material to dentin. MATERIALS AND METHODS: Sixty molar teeth were embedded in a self-curing acrylic resin. All specimens were randomly divided into four groups of teeth, each according to the resin cement used. Sixty cylinders were then luted with one of the four resin materials to dentin (GC EQUIA, Panavia F, Variolink II and Vertise). Then, specimens were stored in distilled water at 37 o C for one day. Shear bond strength of each specimen was measured using a universal testing machine at a crosshead speed of 0.5 mm/minute. The bond strength values were calculated in N, and the results were statistically analyzed using a Kruskal-Wallis and Bonferroni corrected Mann-Whitney U tests. RESULTS: The shear bond strength varied significantly depending on the resin materials used ( P < 0.05). The specimens luted with GC EQUIA showed the highest shear bond strength (25.19 ± 6.12), whereas, the specimens luted with Vertise flow (8.1 ± 2.75) and Panavia F (11.17 ± 3.89) showed the lowest. CONCLUSION: GC EQUIA material showed a higher shear bond strength value than other resin materials.