Long-term Clinical Performance of Monitoring Defective Restorations

Method: A total of 287 defective restorations in 70 patients were monitored in Nagasaki University Hospital between 1995 and 2013.  All patients were under the charge of the principal investigator (SK) and all of them had been regularly checked up for up to 18 years.  The monitored restorations were examined by SK from March 2013 to September 2013.  The restorations were rated clinically acceptable, clinically unacceptable or already replaced according to FDI criteria.  If the monitored restorations were not examined, they were dealt with censored cases.  Survival time was defined as the age when the restoration was repaired, replaced, or censored.  In this study, data obtained from crowns were excluded from statistical analyses.  Survival analysis was performed by the Kaplan-Meier method.  The Cox proportional hazards (PH) model was used to study the dependence of survival time on potential explanatory variables (age, gender, risk, tooth type, restoration type and defect).

Result: Data of 224 monitored restorations in 58 patients, mean age at baseline 60.4 (12.1), were obtained.  Eighteen restorations were not examined and 24 restorations were dealt with censored cases.  Marginal stains with 91 restorations, caries adjacent to 41 restorations and other defects (marginal adaptation, marginal fracture, discoloration, wear, etc.) with 92 restorations were monitored.  Survival rate at 10 years was estimated 83.4%.  Cox proportional hazards model revealed that retreatment risk and reasons for monitoring had great effects on survival rates of defective restorations.  Age and restoration type might also have some effects on the longevity of monitored restorations.

Conclusion: Monitoring defective restorations may help to extend the longevity of restored teeth and preserve tooth structure.  This study was supported by JSPS KAKENHI, Grant Number 23592802.