What are the success rates of anterior restorations used in localised wear cases?

A systematic review and meta-analysis of the literature was carried out assessing the success and survival rate of anterior restorations used in localised wear cases. This also included assessment of posterior teeth re-establishing occlusal contact following use of the Dahl approach. Two large databases; Medline via OVID, and Scopus were used to identify existing literature. The review followed Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) and Meta-analyses guidelines and used the PIO framework [1]. Grey literature was also searched. Publications written in English were included between Jan 1970 and Nov 2020. Population: participants with localised anterior tooth loss. Intervention: anterior composite restorations. Outcome: success and survival rates of the composite restorations. Six cohort studies were included in the final analysis, with three prospective and three retrospective. These studies evaluated the success and survival rates of direct and indirect composite restorations, with a follow-up period ranging from 5 months to 10 years, which took place between 2000 to 2016. Extracted data included: author(s) and year, study type, number and age of participants, number of restorations, location for intervention, type of intervention (direct vs indirect), type of composite, increase in OVD (amount of increase and period to re-establish posterior occlusion), follow up period, definition of failure, number of failed restorations, assessment of intervention and longevity/survival rate. Risk of bias in individual studies was assessed using The Newcastle Ottawa quality assessment scale (NOS) for cohort studies. Outcome measures were standardised as success or survival: The restoration was considered a failure if any other grades were allocated on the modified USPHS criteria. Results were visualised using forest plots. Heterogeneity between studies was measured by I-squared statistic. Sensitivity analysis was performed for each outcome. The survival rates for composite restorations (direct and indirect) at 2–10 years follow-up was 88% (95% CI, 70–90%; I2 = 97%). When significant outliers from one study were removed, and re-analysed, the survival rates increased to 93% at 2–7 years follow-up (95% CI, 85–98%; I2 = 83%). Success rates for composite restorations over the same 2–10 year period was 68% (95% CI, 44–87%; I2 = 98%). Heterogeneity was generally considered high due to large variations in study design, sample size, type of intervention, and follow-up period. The success of the anterior composite Dahl approach in re-establishing posterior occlusion was reported at 85% (95% CI, 73%–94%), which took between 1.5 and 25.4 months. Anterior composite restorations had a high success rate over a period of 2–10 years in patients affected by localised tooth wear, which was higher over a 2–7 year interval. Although, the overall survival rates were considerably lower when accounting for minor and major types of restoration failure. This review supported continued use of anterior composites for restoring worn teeth, which had good short-medium term longevity. However, these conclusions should be interpreted with caution considering the quality of evidence, the heterogeneity of the studies and the limited number of studies included.