The aim of this randomized controlled, double-blinded, split-mouth clinical trial was to evaluate the efficacy of self-assembling peptide P11-4 solution (Curodont™ Repair) with fluoride varnish on the progression of non-cavitated proximal caries compared to casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) with fluoride varnish (MI Varnish™) sodium fluoride (NaF) varnish (Profluorid® Varnish).

The study included 300 permanent molars belonging to 150 children, aged between 7 to 13 years old, who had two non-cavitated proximal carious lesions.

First, the subjects were randomly allocated to three main groups with 50 individuals in each. Then the carious lesions belonging to each subject were randomly assigned to two subgroups based on different treatment agents used: Group 1; P11-4+NaF/NaF, Group 2; P11-4+NaF/CPP-ACP+NaF, Group 3; CPP-ACP+NaF/NaF. Accordingly, test 1 lesions received P11-4+NaF combination, test 2 lesions received CPP-ACP+NaF varnish, and control lesions received NaF varnish alone. At the 6th and 12th months after the clinical applications, Profluorid® Varnish application was repeated for test 1 and control lesions, and MI Varnish™ application was repeated for test 2 lesions. At the end of the 12 months, carious lesion progression status was evaluated radiographically, by using independent visual reading, pair-wise visual reading, and digital subtraction radiography (DSR) methods.

Inclusion Criteria:

• Children who had two permanent molars with non-cavitated proximal carious lesions that included one in the right jaw and the other one in the left jaw, and in contact with neighboring teeth,
• Non-cavitated proximal carious lesions which is radiographically extending into either the outer half of the enamel (E1), the inner half of the enamel (E2) or the outer third of the dentin (D1),
• Children who had not any systemic disease that prevents the application,
• Cooperative children who allowed to radiographic examinations and clinical applications.

Exclusion Criteria:

• There is caries/restoration on the different surface of the tooth to be treated,
• There is caries/restoration on the contact surface of the tooth adjacent to the tooth to be treated,
• Non-cavitated proximal carious lesions which is radiographically extending into the middle third of the dentin (D2) or the inner third of the dentin (D3),
• There is cavitation on the proximal surface of the tooth to be treated,
• Non-cooperative children who had not allow to radiographic examinations and clinical applications,
• Children and parents who denied the participation in the follow-up appointments.

Randomization was performed by a computer-generated random sorting sequence (sealed in opaque envelopes that sequentially numbered randomly selected through).