Factors associated with the success of restorative treatment for root caries: A systematic review with meta-analysis

Objectives: The aims of this systematic review were to estimate the success rates of root caries restorations, and to identify possible factors associated with the success of root caries restorations. Data and Sources: Literature search was conducted in three databases, PubMed, MEDLINE and Web of Science to identify clinical studies reporting on the success of restorative treatment for root caries. Factors that may influence clinical outcomes of the restorative treatment were summarized and analyzed. Study selection: A total of 4116 records were identified, and 9 articles were eligible to be included. A total of 415 participants with 1174 root caries restorations were analyzed. The short-term (6-month) estimated success rates (ESRs) (95 % CI) of root restorations with per protocol (PP) and intention-to-treat (ITT) approach were 95.1 % (92.9 % to 97.3 %) and 90.5 % (86.8 % to 94.1 %), respectively. The long-term (24-month) ESRs were 82.2 % (73.9 % to 90.6 %) and 73.8 % (64.0 % to 83.5 %) by using the PP and ITT approaches, respectively. Resin composite restorations had a higher ESR compared to glass ionomer cement restorations at 12-month follow-up (96.3 % vs. 86.9 %, p = 0.037), but no significant differences were found at 6-month and 24-month follow-ups (p > 0.05). Besides filling material, no other factors with statistically significant association with treatment success could be identified, including study setting, material mixing method, moisture control method, use of liner or not, and restorative technique. Conclusion: The overall success rate of root caries restorations is good in the short-term (6-month) but decreases over time, with an approximately 20 % failure rate after two years. Complete/partial loss of restoration and gross marginal defect were the main reported reasons accounted for failure. No studied factor has clear evidence to support its association with long-term (24 months or longer) success of root caries restoration. Clinical Significance: This review provides up-to-date evidence on the overall success rates of root caries restorations. No compelling evidence shows any studied factor is related to the long-term success of root caries restoration, whilst there is a tendency to observe higher success rates of resin composite compared to glass ionomer cement restorations.