Study protocol for a diagnostic randomized clinical trial to evaluate the effect of the use of two clinical criteria in the assessment of caries lesions around restorations in adults: the Caries Cognition and Identification in Adults (CaCIA) trial

BACKGROUND: The assessment of restored teeth in dentistry remains a challenge, mainly related to the detection of caries around restorations. There is a diversity of clinical criteria available to assess the caries lesions, resulting in differences in the dentists’ diagnosis and treatment decisions. In addition, there is a lack of evidence regarding the best criteria to detect caries lesions around the restorations. Thus, the present protocol aims to evaluate the effect of using 2 visual criteria to assess restored teeth on the outcomes related to oral health in adults. METHODS: The design protocol of the Caries Cognition and Identification in Adults trial correspond to a triple-blind randomized, controlled clinical trial with parallel-groups. Two groups will be compared: patients who will receive the diagnosis and treatment decision according to FDI (World Dental Federation) criteria—FDI group; and patients who will receive diagnosis and treatment decision according to the “Caries Associated with Restorations or Sealants” criteria defined by the International Caries Classification and Management System (ICCMS group). The participants will be followed up after 6, 12, 18, 24, and 60 months, and the restoration failure will be the primary outcome. The analysis will be conducted through Cox regression with shared frailty. The impact of oral health on quality of life and the cost-effectiveness of the methods used will be the secondary outcomes. Two-tailed analyzes will be used, considering a level of significance of 5%. DISCUSSION: This is the first clinical trial to assess the effect of using two visual methods to detect caries lesions around restorations on the outcomes related to oral health in adults. The findings of this study will define what is the best diagnostic strategy for the assessment of caries around restorations in permanent teeth. Trial registration NCT03108586 (registered 11 April 2017).