Fracture toughness of a ceramic-resin interface.
OBJECTIVE
The purpose of this study was to compare the interfacial fracture toughness of smooth and roughened ceramic surfaces bonded with a luting resin using an optimized method of silane treatment.


METHODS
Ceramic discs were prepared with four different surface preparations (n=20) consisting of (1) polished, (2) gritblasted, (3) hydrofluoric acid etched and (4) gritblasted and etched. The ceramic discs were then covered by a PTFE tape with a chevron shaped circular hole. The exposed surfaces were treated by an optimized silane treatment followed by an unfilled resin and then a luting resin. Specimens were then stored in distilled water at 37 degrees C for (A) 24h and (B) 30 days. The interfacial fracture toughness was measured, the mode of failure and fracture surfaces were also examined under a stereo-zoom microscope and a scanning electron microscope.


RESULTS
One-way ANOVA showed that there was no statistically significant difference in the mean interfacial fracture toughness for groups A1-A4 (P>0.05). However, the mean interfacial fracture toughness for group B1 was significantly different from that for groups B2, B3 and B4 (P<0.05). Independent-samples t-test results showed that there was a significant increase in the G(Ic) mean value for groups B2 and B3 after 30 days water storage (P<0.05). The modes of failure were predominantly interfacial or cohesive within the resin.


CONCLUSIONS
It can be concluded that micro-mechanical retention by gritblasting the ceramic surfaces could be sufficient with no need for HF acid etching the ceramic surfaces when an appropriate silane application procedure is used.
Moharamzadeh
Keyvan
K
School of Clinical Dentistry, University of Sheffield, Claremont Crescent, Sheffield S10 2TA, United Kingdom. k.moharamzadeh@sheffield.ac.uk
Hooshmand
Tabassom
T
Keshvad
Alireza
A
Van Noort
Richard
R
D000134:Acid Etching, Dental; D000179:Acrylates / Q000737:chemistry; D000537:Aluminum Oxide / Q000737:chemistry; D001840:Dental Bonding; D003775:Dental Polishing; D003776:Dental Porcelain / Q000737:chemistry*; D006801:Humans; D006858:Hydrofluoric Acid / Q000737:chemistry; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry; D012826:Silicone Elastomers / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
D000179:Acrylates; D008689:Methacrylates; C080875:Mirage; D019279:Resin Cements; D012821:Silanes; D012826:Silicone Elastomers; D014867:Water; D003776:Dental Porcelain; C017492:methacryloxypropyltrimethoxysilane; C040415:heliobond; D000537:Aluminum Oxide; D006858:Hydrofluoric Acid