Microshear fatigue testing of tooth/adhesive interfaces.
OBJECTIVE
The objective of the present study was to determine the fatigue resistance of several contemporary dentin adhesives as well as a resin-modified glass-ionomer cement.


METHODS
Cyclic loading of the adhesive interface was achieved by a microshear fatigue setup following a staircase approach, where the stress level at which 50% of the specimens fail after 10(4) cycles was calculated as the median microshear fatigue resistance (muSFR).


RESULTS
For all products tested, the muSFR was lower than the microshear strength. A wide spread in muSFR was observed, ranging from 24% to 76% of the quasi-static microshear strength, irrespective of the type of adhesive used.


CONCLUSIONS
The results of this study show that the microshear test setup is a discriminative and reproducible way of testing tooth/adhesive interfaces, even at relatively low stresses. The results clearly indicate that such interfaces are vulnerable to progressive damage by cyclic loads. Further, at present there is not one bonding approach, whether "total etch" or "self-etching", that consistently yields higher fatigue resistance: the product factor seems to be of primary importance.
Braem
Marc
M
Lab Dental Materials, University of Antwerpen, Antwerpen, Belgium. marc.braem@ua.ac.be
D000269:Adhesives; D003188:Composite Resins; D001840:Dental Bonding; D003738:Dental Cements; D003799:Dental Stress Analysis; D003804:Dentin; D017220:Dentin-Bonding Agents; D006801:Humans; D008422:Materials Testing; D019279:Resin Cements; D033081:Shear Strength
D000269:Adhesives; D003188:Composite Resins; D003738:Dental Cements; D017220:Dentin-Bonding Agents; D019279:Resin Cements