Introduction: Minimally invasive procedures for small occlusal lesions in primary dentition are an important part of the new restoration methods that can be successfully applied in children. The objective of this study was the evaluation of the clinical performances of the occlusal direct restorations in primary molars, applied by the minimally invasive method, using adhesive materials, in comparison with the classical method, using amalgam. Material and methods: A number of 258 direct occlusal restorations were placed in 144 patients with a mean age of 5 years, 5 months. The restorations were grouped in two study samples according with the cavity preparation technique, classical (124) and minimally invasive (134). Results: The restorations' median survival time, calculated using both the Kaplan-Meier and the survival tables methods, showed differences between the study samples. The median survival time of the classical amalgam restorations (4,55 years) was higher than in the minimally invasive restorations (4,02 years) (p Keywords: durability, direct restoration, minimally invasive, classical restoration