Atypical carious cavities could be defined as carious lesions in more than 2 surfaces of the same tooth. Dental practitioners have shown difficulties related to material's maintenance in such type of cavities and therefore, several treatment options have been used. However, most of them have shown a great failure percentage. A randomized clinical trial will be developed with the objective of assessing the Hall technique in comparison with the composite resin incremental technique in 464 primary molars' atypical carious lesions of children between 4 and 9 years old. Initially, two previously calibrated examiners will perform caries diagnosis by means of visual assessment and intraoral examination. Selected teeth will be randomly allocated into two groups. Teeth in the first group will be submitted to prefabricated stainless steel crowns treatment (Hall technique); and the other, to composite resin incremental technique, which will be always placed under rubber dam isolation. Lesions' clinical and radiographic follow-up will be conducted after 6 and 12 months.