Effects of different re-wetting techniques on dentin shear bond strengths.
OBJECTIVE
For contemporary hydrophilic resin adhesive systems, bonding to dentin is improved if the substrate is maintained in a hydrated state following acid-etching. The purpose of this study was to compare the dentin shear bond strengths of two single-bottle adhesives (one acetone-based and one ethanol-based) applied under different etched-dentin conditions: dry, wet, or dry and re-wetted with different solutions.


METHODS
Bovine incisors (N = 120) were mounted in acrylic, polished to 600-grit, and randomly assigned to 12 groups (n = 10). Dentin was etched for 15 seconds using 35% phosphoric acid, rinsed, and either blot-dried, air-dried, or air-dried and re-wetted with different solutions (distilled water, Gluma Desensitizer, Aqua-Prep, and 5% glutaraldehyde in water). Two adhesives (Single Bond and Prime & Bond NT) were applied to each of the surface conditions following manufacturers' instructions. After adhesive application and curing, composite was applied in a No. 5 gelatin capsule and light-cured. Specimens were loaded in shear, using an Instron at 5 mm per minute. Shear bond strengths were calculated by dividing the failure load by the bonded surface area. Data were subjected to analysis of variance (ANOVA) and a post hoc Tukey test.


RESULTS
Mean shear bond strengths ranged from 12.5 to 26.6 MPa for Single Bond and from 5.6 to 14.7 MPa for Prime & Bond NT. Significant differences were found in both groups of materials (p < .001). The three highest mean bond strengths were obtained (in order) on dentin that was re-wetted with Gluma Desensitizer, re-wetted with Aqua-Prep, or never dried. Differences between these surface conditions were not statistically significant for either material.
Ritter
A V
AV
Department of Stomatology, Operative Dentistry Division, Federal University of Santa Catarina, Florianópolis, SC, Brazil. Andre_Ritter@dentistry.unc.edu
Heymann
H O
HO
Swift
E J
EJ
Perdigäo
J
J
Rosa
B T
BT
D000096:Acetone / Q000737:chemistry; D000134:Acid Etching, Dental; D000704:Analysis of Variance; D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002417:Cattle; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry; D005976:Glutaral / Q000737:chemistry; D008689:Methacrylates / Q000737:chemistry; D010756:Phosphoric Acids / Q000008:administration & dosage; D011109:Polymethacrylic Acids / Q000737:chemistry; D011897:Random Allocation; D012997:Solvents / Q000737:chemistry; D013223:Statistics as Topic; D013314:Stress, Mechanical; D013499:Surface Properties; D014867:Water / Q000737:chemistry; D014906:Wetting Agents / Q000737:chemistry*
C121036:Aqua-Prep; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D010756:Phosphoric Acids; D011109:Polymethacrylic Acids; C103500:Prime & Bond; D012997:Solvents; D014906:Wetting Agents; C111486:gluma desensitizer; C115612:single bond; D014867:Water; D000096:Acetone; D000431:Ethanol; D017438:Bisphenol A-Glycidyl Methacrylate; D005976:Glutaral