RESUMEN
AIM: This study was conducted to evaluate the effect of mechanical alteration of enamel surface on shear bond strength in different bonding techniques. MATERIALS AND METHODS: Seventy samples were fabricated and randomly divided into three groups: Group A (n = 30) - prepared enamel surfaces, Group B (n = 30) - unprepared enamel surfaces, and Group C (n = 10) - prepared enamel surfaces + etch and rinse which served as a control group. Group A and Group B were further divided into three subgroups (n = 10), sub-Group A1, B1 (nanohybrid composite + self-etch), sub-Group A2, B2 (self-adhering composite), and A3, B3 (self-adhering composite + self-etch). Teflon ring molds were used to make composite resin cylinders with the specific bonding protocol of each group. Shear bond strength testing was conducted, and data were analyzed. RESULTS: Mean shear bond strength values were as follows: C> A1> A3>A2>B1> B3> B2. CONCLUSIONS: Prepared enamel surfaces resulted in higher shear bond strength values as compared to unprepared enamel surfaces. Prior application of self-etch agent resulted in higher shear bond strength values of self-adhering composite in prepared and unprepared enamel surfaces.
RESUMEN
AIMS AND OBJECTIVES: To compare tensile bond strength of an 'etch-and-rinse' bonding agent (Single bond,3M ESPE, MN, USA) with an 'all-in-one' bonding agent (iBond, Heraeus Kulzer, NY, USA) on cut and uncut enamel surfaces. The null hypothesis tested is that the 'all-in-one' bonding agent matches the 'etch-and-rinse' bonding agent in terms of tensile bond strength to enamel. MATERIALS AND METHODS: Forty extracted human mandibular teeth were used for the study. Twenty teeth with intact enamel surfaces were divided into two groups of 10 teeth each. The enamel surfaces of the 20 teeth were prepared and assigned to two more groups of 10 teeth each. One group each of intact and prepared enamel surfaces were used to bond with the 'etch-and-rinse' bonding agent [Single bond (SB), 3M ESPE, MN, USA] and the other two groups one each of intact and prepared enamel surfaces were used to bond with the 'all-in-one' bonding agent [ iBond (IB), Heraeus Kulzer, NY, USA]. The tensile bond strength was measured on the universal testing machine (Unitek, 9450 PC, FIE, INDIA) at a cross head speed of 1 mm / minute. RESULTS: The results were statistically analyzed using a one-way ANOVA and student 't' test. The values for the 'etch-and-rinse' bonding agent SB were significantly higher for both the cut and uncut surfaces, compared to the 'all-in-one' bonding agent IB (P < 0.05). The all-in-one bonding agent resulted in a higher bond strength on the cut enamel surfaces. CONCLUSIONS: Based on the results, it is advisable to use the 'etch-and-rinse system' in a clinical situation requiring bonding on enamel alone.
RESUMEN
OBJECTIVES: The purpose of this in vitro study was to evaluate whether mechanical alteration of the enamel surfaces with air abrasion and bur abrasion techniques could enhance the bonding performance of a three step and a self etching adhesive resin systems to enamel. METHODS: 126 extracted lower human incisor teeth were used. The teeth were divided into three groups including 40 teeth each. First group; teeth were used as control and no preparation was made on enamel surfaces, 2(nd) group; outer enamel surfaces were air abraded, 3(rd) group; outer enamel surfaces were abraded mechanically with a diamond fissure bur. Cylinder composite resin blocks were bonded to the buccal enamel surfaces with two bonding systems (20 specimens in each group). Bond strengths to enamel surfaces were measured at a cross-head speed of 1 mm/min. The data were analyzed by ANOVA and Duncan Tests. To examine interface composite resin/enamel surfaces at scanning electron microscopy, remaining 6 teeth were used. Fracture analysis was performed using an optical stereomicroscope. RESULTS: Bond strengths values of Solid Bond were significantly higher than bond strengths of Clearfil SE Bond for all types of enamel (P<.05). Shear bond strength values obtained with Solid Bond (three step system) to three types of enamel surfaces [air-abraded (30.25+/-7.00 MPa), bur-abraded (29.07+/-3.53 MPa), control (31.74+/-7.35 MPa)] were close to each other (P>.05). The macroscopic mode of failures for bonding systems, SB and SE Bond appeared to be adhesive and cohesive in nature. CONCLUSIONS: In order to get better bond strength values with self etching systems, it is advisable to prepare enamel surfaces with bur or air abrasion, but it enamel preparation is not necessary for three step systems.