Is a calcium hydroxide liner necessary in the treatment of deep caries lesions? A systematic review and meta‐analysis

: The aim of this systematic review and meta-analysis was to evaluate whether the use of calcium hydroxide (CH) liner improves the clinical success in the treatment of deep caries lesions of primary and permanent teeth. The review was reported in accordance with the PRISMA Statement. Only studies that evaluated deep carious lesions treated with and without a CH liner were included. The required outcomes had to be obtained by clinical, radiographic or laboratory evaluations. Statistical analyses were performed with the RevMan 5.2 program (The Cochrane Collaboration, Copenhagen, Denmark) for randomized clinical trials with at least 12 months of follow-up, using fixed-effect models at a significance level of P < 0.05. The literature search was performed in eight databases: PubMed (MEDLINE), Lilacs, IBECS, BBO, Web of Science, Scopus, SciELO and The Cochrane Library. A total of 17 studies were included (15 in primary teeth, two in permanent teeth). The overall risk difference for CH versus adhesive system in primary teeth was 0.06 [95% CI -0.01 to 0.13], and the overall risk difference for CH versus GIC was 0.10 [95% CI -0.01 to 0.22], with no significant differences between materials. CH liner did not influence the clinical success of treatment for deep caries lesions of primary or permanent teeth. Although the present analysis demonstrated that use of CH liner in deep caries lesions was unnecessary, the evidence was of moderate to very low quality; thus, further well-designed, randomized and controlled clinical trials are necessary to provide stronger recommendations.