Single crown vs. composite for glass fiber post-retained restorations: An 8-year randomized clinical trial

OBJECTIVES

This study aimed to compare the success and survival rates of metal-ceramic crowns and composite resin restorations applied in root filled teeth that received a glass fiber post.

METHODS

A prospective, randomized controlled trial, with equivalent parallel groups was designed. Eighty-two teeth were randomly allocated to the metal-ceramic or composite resin groups. Multivariate Cox regression analysis with shared frailty for patients and Kaplan-Meier curves were performed using success and survival rates (p<0.05).

RESULTS

Seventy-five post-retained restorations (34 metal-ceramic crowns and 41 composite restorations) in 62 patients were analyzed. The median follow-up was 8.1 years [IQR 4.0-9.9]. Twenty-seven failures were observed. Twenty-two failures (81.5 %) were observed in the composite resin group, of which six (27.3 %) were not repairable. Five failures (18.5 %) were observed in the metal-ceramic crown group, of which three (66.6 %) were non-repairable. The cumulative success rate at 8 years was 85.0 % for crowns (AFR=1.31 %) and 43.2 % for composite resins (AFR=6.58 %), while the survival rate was 93.8 % for crowns (AFR=0.52 %) and 97.6 % for composite resins (AFR=0.20 %). Considering the success rates, adjusted multivariate Cox regression showed that composite resin had a Hazard Ratio of 5.07 (95 %CI, 1.99-12.89) greater than the metal-ceramic crown. No significant difference in the failure risk was observed when the survival rates were considered (HR=0.38, 95 %CI (0.10 - 1.44), p = 0.156). Co-variables did not affect the success and survival rates (p>0.05).

CONCLUSIONS

Metal-ceramic crowns showed a higher success rate than composite restorations. The survival rates were similar, but composite restorations presented a higher need for repairs.

CLINICAL SIGNIFICANCE

Post-retained composite restorations may need more reinterventions during the lifecycle, although more preservation of sound tooth structure is expected with a large restoration of resin post-and-core. These aspects have to be discussed with the patient for decision-making planning.

Effect of Remaining Cavity Wall, Cervical Dentin, and Post on Fracture Resistance of Endodontically Treated, Composite Restored Premolars

PURPOSE

The aim of this study was to examine the effect of remaining buccal cavity wall, remaining cervical tissue, and post on the fracture strength of endodontically treated restored premolars.

MATERIALS AND METHODS

Teeth were randomly allocated to 10 experimental groups (n=10) according to cavity design and presence or absence of post or to a control group. After thermal and mechanical aging, ramped loading until fracture was performed.

RESULTS

A high cervical outline (417 N) and the presence of a post (189 N) increased fracture strength, but both factors together had an antagonistic effect of -218 N, resulting in a higher strength of not 606 N (417+189) but 388 N. The risk of catastrophic failure increased (OR=3.17) when a post was present.

A practice-based study on the survival of restored endodontically treated teeth

INTRODUCTION

This retrospective study evaluated the survival of endodontically treated teeth (ETTs) and investigated factors influencing restoration and tooth survival.

METHODS

Data from 795 ETTs were recorded, and success (restoration still intact) and survival (restoration intact or failed/repaired/replaced and tooth still in situ) were analyzed using Kaplan-Meier statistics. A multivariate Cox regression analysis was performed to assess the variables influencing success and survival.

RESULTS

At the end of the observation period (mean observation time = 4.48 years), 45 teeth had been extracted (annual failure rate for survival = 1.9% at 9.6 years) and 114 restorations had received a restorative follow-up treatment (annual failure rate for success = 4.9% at 9.6 years).

CONCLUSIONS

ETTs showed acceptable survival and success in the long-term. Variables showing significant influence on survival were the number of teeth in the dentition and the presence of decay at the moment the patient entered the practice.