Efficacy of the infiltration technique in proximal carious lesions of primary molars: randomized controlled clinical trial with 24 months of follow-up

The purpose of this randomized controlled trial split month was evaluate the efficacy of microinvasive caries infiltration technique in proximal carious lesions in primary molars after 12 and 24 months of treatment through paired radiographic analysis. Fifty children aged 5 to 9 years, with at least two non-cavitated proximal lesions and radiographic extension involving 1/2 of the enamel or outer 1/3 of dentin were included, allocated in test group (resin infltration, Icon®, DMG, Hamburg, Germany) and control group (fluoride toothpaste and dental floss) and treated in a previous study. The 50 patients who received the therapeutic intervention in the previous study were eligible for the study sample. Patients were asked twice a year to reinforce oral hygiene instruction and a new clinical dental examination and, annually, submitted to digital radiographic examination. The radiographic analysis was done by blind gold standard evaluator to the allocation of the teeth (test and control), and to the clinical data of the patients. The differences between the test group and the control group, in relation to the progression of carious lesion, were analyzed using the McNemar test with a significance level of 0.05. Twenty-two patients attended the 12-month follow-up visit, and were added to the 20 patients already evaluated in the previous study, thus totaling the sample of 42 patients (42/50). Clinically only 1 control lesion progressed to cavitation. Radiographically, 11.9% of the test lesions and 33.3% of the control lesions progressed. In 10 patients only the control lesion progressed, whereas in 1 patient only the test lesion progressed; In 4 patients progressed both the test and control lesions (p = 0.012). Another twenty-two patients (22/38) attended the 24-month follow-up visit. Clinically, 5 lesions cavitated (2 from the test group and 3 from the control group). Radiographically, 22.7% lesions of the test group and 50% lesions of the control group and progressed. In 6 patients only the control lesion progressed, whereas in no patient only the test lesion progressed; In 5 patients progressed both the test and control lesions (p = 0.031). The standard of oral hygiene did not change throughout the reviews. The caries risk of the patient did not influence the outcome of the study (p> 0.05). The therapeutic efficacy of resin infiltration at 12 and 24 months was 21.4% and 27.3%, respectively. No adverse effects were found related to the infiltration technique. It can be concluded that the resin infiltration technique is a safe, effective and viable micro-invasive method for the treatment of deciduous molars.