Repair Versus Replacement of Failed Restorations in Primary Teeth

Repair Versus Replacement of Failed Restorations in Primary Teeth: Protocol for a Non-Inferiority Randomized Clinical Trial

Dental caries affect approximately 573 million children globally, and the management of failed restorations is a frequent clinical issue in pediatric dentistry. Although complete replacement of restorations is traditionally the most commonly adopted approach, repair represents a minimally invasive alternative that preserves healthy dental structure and reduces the risk of pulpal complications. Studies in permanent teeth demonstrate that repair may present longevity similar to replacement; however, there is no robust evidence regarding this comparison in primary teeth. This randomized controlled clinical trial, with parallel groups and a 1:1 allocation ratio, aims to evaluate the non-inferiority of repair compared with replacement of failed restorations in primary molars, using encapsulated high-viscosity glass ionomer cement. Children aged 4 to 8 years with at least one failed restoration eligible for repair in primary molars will be included. Randomization will be stratified by number of surfaces. Teeth (n=824) will be randomly allocated to one of the groups: repair or replacement. The primary outcome will be restoration survival at 24 months. Cost-effectiveness will be evaluated as a secondary outcome. Statistical analysis will use Kaplan-Meier curves and Cox regression with shared frailty (¿=5%).

Inclusion Criteria:

• Children aged 4 to 8 years;
• Presence of at least one defective restoration in a primary molar, involving no more than 3 surfaces;
• Absence of clinical and radiographic signs of pulp involvement;

Exclusion Criteria:

• Tooth without pulp vitality or requiring endodontic treatment;
• Loose or mobile restoration;
• Presence of fistula, abscess, or history of pain;
• Tooth mobility incompatible with the physiological exfoliation timeline;
• Parents/guardians who do not consent to participation by signing the ICF, or children who do not assent to participate in the study.