Relationship of dentin shear bond strengths to different laboratory test designs.
OBJECTIVE
To compare 6 shear bond test procedures using 2 primers by evaluating differences in strength and fracture surfaces.


METHODS
Part I - a 2(3)-factorial design evaluated the effects of (1) 2 primer systems, (2) the dentin moisture level, and (3) the application technique defining the bond area. The outcome of Part I then led to choosing for Part II one primer system, applying the primer the entire surface with moist dentin as the substrate while comparing 6 shear test designs: (1) knife-edged chisel-on-iris; (2) similar to 1 with support added to the tooth; (3) chisel on composite plug; (4) similar to 3 with support added; (5) wire loop on composite plug; (6) modified Watanabe assembly.


RESULTS
In Part I mean shear bond strengths (SBS) ranged from 14-36 MPa. SBS was highest for either primer when it was applied to moist dentin over the entire dentin surface. Each of the factors, moisture level, primer system and application technique significantly affected SBS (3-way ANOVA, P<0.05). The effects from each primer system on SBS depended on the surface moisture or the application technique, indicating significant interactions. In Part II, mean SBS ranged from 18-32 MPa with Groups 1 and 2 having significantly higher bond strengths than the others (P<0.05).
Dickens
Sabine H
SH
Polymer Program, Paffenbarger Research Center, American Dental Association Health Foundation, National Institute of Standards and Technology, Gaithersburg, MD 20899-8546, USA. sabine.dickens@nist.gov
Milos
Michael F
MF
D000134:Acid Etching, Dental; D000704:Analysis of Variance; D001840:Dental Bonding; D003804:Dentin / Q000502:physiology* / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D004867:Equipment Design; D006801:Humans; D008422:Materials Testing / Q000295:instrumentation / Q000379:methods*; D016369:Smear Layer; D013223:Statistics as Topic; D013314:Stress, Mechanical; D013499:Surface Properties; D014867:Water / Q000737:chemistry
D017220:Dentin-Bonding Agents; D014867:Water