Universal adhesives and non-carious cervical lesions. A systematic review and meta-analysis

OBJECTIVES The prevalence of non-carious cervical lesions (NCCLs) is considered to be nearly 50% on the world level, with older populations being more severely affected. NCCLs can cause both esthetical and functional problems. Universal adhesives are the latest generation of adhesive systems which, according to the manufacturers’ instruc­tions, can be used in various adhesive strategies: Etch-and-rinse (EAR), self-etch (SE) and selective-enamel-etch (SEE). The purpose of this paper was to answer the following PICOS question: “Is the risk of retention loss and post-operative sensitivity (POS) equal for EAR and SE appro­ach when restoring NCCLs with universal adhesives and composite restorations?”. MATERIALS AND METHODS A comprehensive literature search was performed with no lan­guage and date restriction throu­gh PubMed, Scopus and Web of Science. Cochrane Risk of Bias Tool was used to assess the risk of bias. Meta-analyses were performed using RevMan; fixed-effects models were applied, and heterogeneity was tested using the I2 index. The significan­ce level was set at p <0.05. RESULTS AND CONCLUSIONS The initial search yielded with 244 papers and after applying exclusion criteria 22 papers were included in qualitative, while 14 papers were included in the quantitative synthesis. Overall, the reviewed studies had no major problems regarding the study design and reporting of results. There was a statistically significant difference for the outcome retention at 6 (p = 0.02; RR = 0.53, [0.3, 0.94]),12 (p = 0.005; RR = 0.22, 95% CI [0.08, 0.63]) and 18/24 (p = 0.0002; RR = 0.32, 95% CI [0.17, 0.58]) months follow-up between the two adhesive strategies, indicating that the risk for retention loss was hi­gher in SE approach. The chance for baseline POS occurrence was higher when universal adhesives were used in EAR compared to SE mode (p = 0.008; RR = 2.05, 95% CI [1.21, 3.48]). Data from 12 and 18/24 months follow up were not heteroge­neous (I2 = 0%), while the data from 6 and 36 months (chi2 test, p = 0.02, I2 = 63%; chi2 test, p = 0.13, I2=56%, re­spectively) follow-up showed substantial heterogeneity. The results of this systematic review suggest that using uni­versal adhesives in EAR strategy can provide more favorable retention compared to SE approach up to 2 years of follow-up. The baseline POS was more likely to occur in EAR adhesive strategy. CLINICAL SIGNIFICANCE The choice of adhesive stra­tegy influences the clinical behavior of composite restorations placed with universal adhesives in NCCLs. Using universal adhesives in EAR strategy can cause post-operative sensitivity and initial patients’ discomfort, however, it provides more predictable retention compared to SE approach.