Longevity of Posterior Restorations in Military Personnel

Objective:

The purpose of this study was to determine if the frequency of restoration replacement differs based on the type of restorative material.

Method:

Investigators identified dental records of Navy and Marine Corps personnel who had at least one posterior tooth restored with a resin-composite during active duty. Dental amalgam restorations in these records were included in this study.  The date of restoration placement and the number of resin-composite and dental amalgam restorations that required replacement were determined from the progress notes.  The dates of diagnosis for replacement or the last entry in the dental record was recorded to determine time at risk.  A proportional hazard model, adjusted for number of tooth surfaces restored, was employed to determine if a difference existed between replacement rates of resin-composite and dental amalgam restorations.

Result:

After reviewing 1,612 dental records, 181 (11.2%) subjects met study criteria. A total of 738 (348 resin-composite; 390 amalgam) restorations were identified for inclusion in the study with a mean follow-up of 2.6 years (resin-composite 2.1 years; amalgam 3.0 years). There were 438 single surface restorations noted (265 resin-composite; 173 amalgam), of which 3.4% of the resin-composites required replacement while only 1.7% of the amalgam restorations needed replacement.  Of the 300 multi-surface restorations (83 resin-composites; 217 amalgams), 9.6% of the resin-composites and 9.7% of the multi-surface amalgams required replacement. After adjusting for the number of tooth surfaces included in the restoration, no significant difference existed in the replacement rates for resin-composite or amalgam posterior restorations.

Conclusion:

No significant difference existed between the replacement rates of resin-composite and amalgam posterior restorations (HR=1.81; 95% CL 0.86-3.82). However, a significant elevation of risk was observed for replacement of multi-surface restorations when compared to single-surface restorations (HR=2.93; 95% CL 1.36-6.31).