Background This non-inferiority randomised clinical trial aimed to evaluate the survival of direct bulk fill composite resin restorations in primary molars using different methods of moisture control: rubber dam isolation (RDI—local anaesthesia and rubber dam) and cotton roll isolation (CRI—cotton roll and saliva ejector). Secondary outcomes included baseline and 2-year incremental cost, self-reported child’s pain scores and patient behaviour during the restorative procedure. Methods A total of 174 molars (93 children) with dentine caries lesions were randomly allocated to study groups (RDI or CRI) and restored with bulk fill composite resin by trained operators. Two blinded examiners assessed the restorations for up to 24 months. Wong-baker faces and Frankl's behaviour rating scales were used for accessing the child's pain and behaviour, respectively. The primary outcome (restoration survival) was analysed using the two-sample non-inferiority test for survival data using Cox Regression (non-inferiority/alternative hypothesis HR > 0.85; CI = 90%). Bootstrap Linear regression was used for cost analysis and logistic regression for pain and behaviour analysis (α = 5%). Results After 2-years, 157 restorations were evaluated (drop-out = 9.7%). The survival rate was RDI = 60.4% and CRI = 54.3%. The non-inferiority hypothesis was accepted by the Cox Regression analysis (HR = 1.33; 90% CI 0.88–1.99; p = 0.036). RDI was 53% more expensive when compared to the CRI group. No differences were found between the groups regarding pain (p = 0.073) and behaviour (p = 0.788). Conclusion Cotton roll isolation proved to be non-inferior when compared to rubber dam for composite restorations longevity in primary molars. Furthermore, the latest presented the disadvantage of higher cost and longer procedure time. Clinical Significance The moisture control method does not influence the longevity of composite restorations in primary molars. Cotton roll isolation proved to be non-inferior to rubber dam isolation and is a viable option for restoring primary molars. Clinical trial registration registered NCT03733522 on 07/11/2018. The present trial was nested within another clinical trial, the CARies DEtection in Children (CARDEC-03-NCT03520309).

ObjectiveThis randomized clinical trial aimed to evaluate the influence of two caries diagnosis strategies, and subsequent management, on oral health‐related quality of life (OHRQoL) of preschoolers. Additionally, the association of the OHRQoL outcomes with the clinician‐centred primary outcome used in the main study was also explored.Materials and MethodsThis study refers to the OHRQoL secondary outcomes analyses of the so‐called RCT ‘CARDEC‐1’. Three‐ to 6‐year‐old children were randomly allocated in two caries detection strategies in primary molars: visual inspection (VIS) or visual + radiographic (RAD) assessment. Participants were diagnosed and treated according to the allocated group and followed up for 2 years. Caregivers answered the Early Childhood Oral Health Impact Scale (ECOHIS) at baseline and after 2 years. Intention‐to‐treat analysis was performed. ECOHIS scores at baseline and 2 years later were compared using the Mann–Whitney test. Effect sizes, change scores and the minimally important difference (MID) were also compared between groups. Additional analysis was performed to assess if OHRQoL variables could reflect the primary clinical outcome (number of new operative interventions during the follow‐up), observing if these met the Prentice criteria.ResultsTwo hundred and five children had the ECOHIS answered in both period times (18.7% attrition rate). There was a decrease in total ECOHIS scores, as well as for different domains for both trial groups, with effect sizes varying from 0.43 to 0.77. Comparisons between groups, however, did not show significant differences. In the additional analysis, the OHRQoL variables met the Prentice criteria and presented the same trends observed with the clinician‐centred primary endpoint.ConclusionCaries detection performed by visual inspection alone or associated with radiographic method does not influence the long‐term impact on OHRQoL. Furthermore, OHRQoL variables reflect clinical outcomes in this type of clinical trial. ClinicalTrials.gov NCT02078453.