Effectiveness of conventional treatment using bulk-fill composite resin versus Atraumatic Restorative Treatments in primary and permanent dentition: a pragmatic randomized clinical trial

Background: Clinical studies are being conducted in less strict conditions in order to establish an adequate scientific basis for decision making. The aim of this pragmatic randomized clinical trial is to evaluate the effectiveness of single and multiple-surfaces restorations performed following the Atraumatic Restorative Treatment (ART) premises compared with Conventional Treatment (CT) using bulk fill composite restorations in primary and permanent teeth. Methods/design: A total of 1,214 5-to-13 year-old children with at least one single or multiple-surface dentin caries lesion in primary or permanent molars will be selected in public schools of Barueri-SP, Brazil. The participants will be randomly assigned into 2 groups: CT (caries removal with bur and restoration performed with Scotchbond (TM) Universal Adhesive system associated with Filtek Bulk Fill - 3 M/ESPE) and ART (Caries removal with hand instruments and restoration with high viscosity glass ionomer cement Ketac Molar Easy Mix - 3 M/ESPE). Ten untrained dentists will perform the treatment in in dental offices located at public schools. The restorations will be evaluated after 6, 12 and 24 months by an independent trained and calibrated examiner. The restoration and tooth survival, the cost-effectiveness analysis between the two groups and the operators' preferences regarding the techniques will be also evaluated. Kaplan-Meier survival analysis and log-rank test will be applied for the restoration and tooth survival. All the average event rates in the two groups will be modelled and compared with a Cox proportional hazard shared frailty model since there is an operator-cluster effect. The significance level for all analyses will be 5 %. Discussion: Our hypothesis is that despite similar expected effectiveness between ART using high viscosity GIC and conventional treatment using bulk fill composite resin when treating single or multiple-surface in posterior primary and permanent teeth, ART will present superior cost-effectiveness. The results of this trial will support decision-making by clinicians and policy makers.