Effect of restoration method on fracture resistance of endodontically treated maxillary premolars.
OBJECTIVE
The aim of the present study was to compare the fracture resistance of endodontically treated maxillary premolars with mesio-occlusodistal (MOD) cavities restored using various restorative materials and luting agents.


METHODS
Eighty extracted human maxillary premolars satisfying certain predetermined criteria were subjected to seven different restoration methods (10 premolars per method). After endodontic treatment, an MOD cavity was prepared in each specimen, and restoration was carried out by one of the following methods: group 1 = control (intact premolars); groups 2 and 3 = restoration using a photo-cure resin composite with and without bonding, respectively; groups 4 and 5 = restoration using a cast-metal inlay with zinc phosphate and adhesive resin cements, respectively; groups 6 and 7 = restoration using a cast-metal onlay with zinc phosphate and adhesive resin cements, respectively; and group 8 = restoration using a hybrid resin onlay. A fracture test was conducted to determine the fracture resistance and fracture mode of each specimen.


RESULTS
Fracture resistance was greatest for teeth restored using a cast-metal onlay cemented with adhesive resin cement, but those fractures that did occur were generally unrestorable. Fracture resistance of teeth restored using a cast-metal inlay was also high. Fracture resistance for teeth restored using a resin composite was significantly lower, but the majority of these fractures were restorable.


CONCLUSIONS
Endodontically treated maxillary premolars with MOD cavities could be successfully restored by cast onlay and inlay restorations luted with adhesive resin cement, but their failure mode was often unfavorable.
Department of Fixed Prosthodontics, Tsurumi University School of Dental Medicine, Yokohama, Japan.
Yoshihiro
Y
Yamada
Yuji
Y
Tsubota
Shunji
S
Fukushima
D001641:Bicuspid / Q000473:pathology*; D003188:Composite Resins / Q000737:chemistry; D003722:Dental Alloys / Q000737:chemistry; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000379:methods; D003738:Dental Cements / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000379:methods*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D007284:Inlays; D008437:Maxilla; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D014082:Tooth Fractures / Q000517:prevention & control*; D019553:Tooth, Nonvital / Q000628:therapy*; D015036:Zinc Phosphate Cement / Q000737:chemistry
D003188:Composite Resins; D003722:Dental Alloys; D003738:Dental Cements; D003764:Dental Materials; D017220:Dentin-Bonding Agents; D019279:Resin Cements; D015036:Zinc Phosphate Cement