The Outbreak of COVID-19.

The objective of this randomized clinical trial is to evaluate the survival of restoration with high viscosity glass ionomer cement (HVGIC) with pre-etching with polyacrilic acid compared with no pre-etching in order to treat occlusoproximais caries lesion in primary molars, as well as the impact of those treatments in the caries lesion progression, the cost-efficacy of the procedures and the discomfort reported by the patient. Children of 4 to 8 years will be selected in the Pediatric Dentistry Clinic of Universidade Ibirapuera. 192 teeth will be randomized in 2 experimental groups: (1) HVGIC restoration with pre-etching and (2) HVGIC restoration with no pre-etching. Will be considered as primary outcome the survival of the restoration evaluated after 6, 12, and 24 months by two trained examiners. The carious lesions progression will be evaluated after 24 months of follow-up. The time of the treatments and the cost of the materials will be considered to estimate the cost-efficacy of each treatment. The discomfort reported by the participant will be measured after each procedure following the Wong-Baker scale. For the primary outcome, Kaplan-Meier survival and the Long-Rank test will be used in order to compare the two groups. Cox regression will be performed in order to evaluate thee influence of explanatory variables on the outcome.

Inclusion Criteria:

• Patients with carious lesion of occlusoproximais in primary molars

Exclusion Criteria:

• Patients will be excluded with special needs, using orthodontics devices and/or systemic diseases which may affect the oral cavity.
• Also, teeth with pulp exposure, spontaneous pain, mobility, presence of abscess or fistula next to the tooth, teeth with restorations, sealants or enamel formation defects will also be excluded.

Individual participant data will be available on Mendeley database.

Double-blind (Patient and Examiner) will not be able to blinding the operator due to the obvious difference between the techniques