Background There is little information regarding the longevity of the restored tooth, considering the health of the pulp-dentine complex, in children who do not sufficiently cooperate with dental treatment.

Aim To evaluate the longevity of primary molar teeth with an occluso-proximal cavity that was treated with the selective removal of carious tissue.

Design A total of 150 children were allocated to two parallel groups: group 1 (G1, n = 70, control, Ketac Molar Easymix®, 3M/ESPE, Seefeld, GE) and group 2 (G2, n = 80, test, Maxxion®, FGM, Joinville, BR). The study was double-blinded, and an operator specialized in paediatric dentistry performed the selective removal of soft dentine and the restoration of the cavity with GIC. During the follow-up periods, the teeth were evaluated via periapical radiography by two trained examiners specialized in radiology. Statistical analysis was performed using Stata 11.2 software (StataCorp, Texas, USA) and a survival curve (Kaplan-Meier).

Inclusion Criteria:

• An active denture caries lesion
• The molars in primary, without anterior restoration, with the exclusive involvement of occlusal and mesial or distal surfaces present (International Caries Detection and Evaluation System, ICDAS score 5)

Exclusion Criteria:

• Those who did not accept care after 3 adaptation sessions
• Teeth with the following characteristics were excluded from the study: spontaneous pain, pressure sensitivity, suspected cellulose involvement, necrosis pulp, fistula, or tooth mobility
• Teeth in which extension of the lesion could lead to pulpal exposure were excluded
• Children whose parents or guardians do not sign an Informed Consent Term

For the radiographic evaluation, the evaluators had no information about the group to which the parent was randomized. Only the periapical tissues were evaluated, and the coronary portion of the restored tooth was concealed with adhesive tape.