Survival of two post systems--five-year results of a randomized clinical trial.
OBJECTIVE
To assess the survival rate of two different post systems after 5 years of service with a prospective randomized controlled trial.


METHODS
One hundred patients in need of a post were studied. Half of the patients received long glass fiber-reinforced posts, while the other half received long metal screw posts. The posts were assigned randomly. After at least 5 years (mean, 61.37 months), follow-ups were established. When a complication occurred prior to this recall, the type and time of the complication was documented. Statistical analysis was performed using the log-rank test and Kaplan-Meier analysis. Additionally, a Cox regression was performed to analyze risk factors.


RESULTS
The survival rate of fiber-reinforced posts was 71.8%. In the metal screw post group, the survival rate was significantly lower, 50.0% (log-rank test, P = .026). Metal posts resulted more often in more unfavorable complications (eg, root fractures); consequently, more teeth (n = 17) had to be extracted. The Cox regression identified the following risk factors: position of the tooth (anterior vs posterior teeth), degree of coronal tooth destruction, and the post system (fiber-reinforced post vs metal screw post). Fiber-reinforced restorations loosened in several patients; in some of these cases (n = 6), patients did not notice this, leading to the extraction of teeth.


CONCLUSIONS
Long metal screw posts should be used with great care in endodontically treated teeth. Besides the selection of the post system, other factors influence the survival of the restoration.
Department of Prosthodontics, University of Heidelberg, Heidelberg, Germany. Marc_Schmitter@med.uni-heidelberg.de
Marc
M
Schmitter
Khaled
K
Hamadi
Peter
P
Rammelsberg
D000134:Acid Etching, Dental / Q000379:methods; D002484:Cementation / Q000379:methods; D003764:Dental Materials / Q000737:chemistry*; D017267:Dental Prosthesis Design; D017269:Dental Prosthesis Repair; D019232:Dental Restoration Failure; D017220:Dentin-Bonding Agents / Q000737:chemistry; D005260:Female; D005500:Follow-Up Studies; D005898:Glass / Q000737:chemistry*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010756:Phosphoric Acids / Q000737:chemistry; D011176:Post and Core Technique / Q000295:instrumentation*; D011446:Prospective Studies; D019279:Resin Cements / Q000737:chemistry; D012307:Risk Factors; D016019:Survival Analysis; D014025:Titanium / Q000737:chemistry*; D014081:Tooth Extraction; D014082:Tooth Fractures / Q000209:etiology; D014092:Tooth Root / Q000293:injuries; D019553:Tooth, Nonvital / Q000628:therapy; D016896:Treatment Outcome; D015036:Zinc Phosphate Cement / Q000737:chemistry
D003764:Dental Materials; D017220:Dentin-Bonding Agents; D010756:Phosphoric Acids; D019279:Resin Cements; C009753:fiberglass; D015036:Zinc Phosphate Cement; D014025:Titanium; C030242:phosphoric acid