Atypical cavities, which involve more than two surfaces, one being buccal or lingual/palatal, are a challenge for restorative dentistry, since the risk of restorative failure is related to the number of surfaces involved. Thus, the purpose of this umbrella project is to conduct a randomized controlled trial (RCT) to evaluate the efficacy and patient-centered outcomes of a chemically activated composite alkasite resin in atypical deciduous molar lesions. Primary molars of children aged 4 to 7 years with at least one atypical cavitary lesion in primary molars will be selected for the RCT. The selected teeth will be randomly divided into: Alkasite chemically activated composite resin and Bulk fill composite resin. Clinical and radiographic follow-up of the lesions will be performed for 6 and 12 months. The effectiveness of the treatments will be evaluated by the longevity of the restorative procedures and paralysis of the lesions. Patient-centered outcomes will also be evaluated.

Inclusion Criteria:

• Children will be included who have at least one posterior tooth with atypical caries lesion.

Exclusion Criteria:

• Patients with special needs will be excluded, with general health conditions that may affect the oral cavity, non-cooperating in relation to the examination, which use orthodontic apparatus and the parents/guardians or children not to consent to their participation in the study. In addition, teeth with pulp exposure, spontaneous pain, mobility, presence of swelling or fistula close to the tooth, furcation or cervical injury, teeth with restorations, sealants or enamel formation defects will be excluded.