title: Effects of different burs on dentin bond strengths of self-etching primer bonding systems.
abstract: This study evaluated the effects of cutting dentin with different types of burs on tensile bond strength using three self-etching primer bonding systems (Clearfil Liner Bond 2 [LB2], Clearfil Liner Bond 2V [2V] and Clearfil SE BOND [SE], Kuraray, Co, Ltd, Osaka, Japan). Thirty-six intact extracted human third molars were ground flat to expose occlusal dentin, followed by polishing the dentin surfaces with #600 SiC paper. The teeth were divided into four groups according to bur type and grit: fine cut fissure steel bur (SB600), cross cut fissure steel bur (SB703), regular grit diamond bur (DB). Controls were abraded with #600 grit SiC paper (AP#600). The dentin surfaces of the SB600, SB703 and DB groups were cut under copious air-water spray with the respective burs mounted in a dental handpiece. The teeth were treated with one of three adhesive systems, then composite buildups were created with Clearfil AP-X (Kuraray Co, Ltd, Osaka, Japan). After soaking in water at 37 degrees C for 24 hours, serial vertical sections (0.7 mm thick, 7-8 slices per one tooth) were made, trimmed to form an hour-glass shape with a 1.0 mm2 cross-section and tensile bond strengths were determined at a cross-head speed of 1 mm/min. Statistical analysis was made using one and two-way ANOVA and Fisher's PLSD test (p<0.05). Eight additional molars were prepared. Burs or abrasive paper were used for SEM observations of the dentin surfaces of each group before and after treatment with the self-etching primers. All adhesive systems yielded the same ranking of bond strengths to the surfaces prepared with different abrasives: from highest to lowest, AP#600 > SB600 > SB703 > DB. This ranking reached statistical significance using Clearfil Liner Bond 2V (p<0.05). Therefore, when cutting dentin, selecting the adequate bur type is important for improved bonding of adhesive systems using self-etching primer to dentin.
authors.affiliation: Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ogata
authors.forename: N
authors.initials: N
authors.lastname: Harada
authors.forename: S
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: M
authors.initials: M
authors.lastname: Nakajima
authors.forename: P N
authors.initials: PN
authors.lastname: Pereira
authors.forename: J
authors.initials: J
authors.lastname: Tagami
mesh_terms: D000134:Acid Etching, Dental; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000295:instrumentation*; D003762:Dental Instruments; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates; D008964:Molar, Third; D019279:Resin Cements; D013718:Tensile Strength
chemical_list: C112274:Clearfil Liner Bond 2; C438313:Clearfil SE Bond; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D019279:Resin Cements