Method to compare mu-tensile bond strength of a self-etching adhesive and mu-cohesive strength of adjacent dentin.
Laboratory results from tensile or micro-tensile testing of adhesive/restorative systems need a gold standard to make their interpretation possible. This can be done by comparing the mu-tensile bond strength (muTBS) of the tested adhesive(s) with the mu-tensile cohesive strength (muTCS) of the adjacent dentin, which is meant to be replaced by the restoration.


OBJECTIVE
To test immediate muTBS of an adhesive/restorative system versus muTCS of the dentin adjacent to the bonded interface, in perfused specimens.


METHODS
Enamel and roots of five-third sound molars were removed and teeth were perfused (30 cm distilled H2O) until after the bonding procedure was completed. Parallel grooves (1.5-mm widex 1.5-mm deep, separated by 1.5mm), were drilled in the exposed dentin, under water refrigeration. Teeth were restored (AdheSE/Filtek Z250). Specimens were sawn from grooves to test muTBS (n = 30) and from between grooves to test muTCS (n = 32) of dentin, adjacent to adhesive interfaces, both areas to be tested at the same relative depth. Areas to be studied were rounded (mean bonded surface area for both groups, BA = 0.68 mm2), and muTBS and muTCS were found. As not all BAs were identical, residuals of muTBS and muTCS values to the regression line relating BA and tensile test results (representing the null hypothesis, i.e. muTBS = muTCS) were compared using a non-parametric test.


RESULTS
Difference in the means of residuals was not statistically significant (two tails p = 0.067).


CONCLUSIONS
mean muTBS of the tested adhesive was not different to mean muTCS of adjacent dentine. The null hypothesis was not rejected.
de la Macorra
José C
JC
Department of Restorative Dentistry, Faculty of Odontology, Complutense University, 28040 Madrid, Spain. macorra@odon.ucm.es
San-Nicolás
Adriana
A
D000180:Acrylic Resins / Q000737:chemistry; D003080:Cold Temperature; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D014867:Water / Q000737:chemistry
D000180:Acrylic Resins; C489662:AdheSE cement; D003188:Composite Resins; D017220:Dentin-Bonding Agents; C444701:Filtek Z250; D019279:Resin Cements; D014867:Water