Aesthetic and conservative restorations render adhesive systems essential for Pediatric Dentistry. There are, however, no protocols firmly established by manufacturers for using it in primary teeth, as the same adhesive protocol is assigned to permanent and primary teeth, disregarding the chemical and morphological differences between these dentin substrates. 1,2 Primary dentin has a higher tubular density, with a larger diameter in peritubular and intertubular dentin and the lower mineral content, 2,3 turning this substrate more reactive to acid conditioners. 4 Therefore, an increased demineralization occurs in primary dentin, producing a thicker hybrid layer and lower bond strength values 4-6 when submitted to the same etching time used for dentin in permanent teeth. 4 The deeper demineralization of primary dentin jeopardizes the adhesion by the collapse of collagen fibrils and calcium phosphate crystal precipitation, and thus, less

Ângela DALLA NORA (a) Andressa DALMOLIN (b) Larissa D'Olanda GINDRI (a) Carlos Heitor Cunha MOREIRA (a) Luana Severo ALVES (b) Júlio Eduardo do Amaral ZENKNER (a)

No abstract

This double-blind, randomized clinical trial aimed to compare the clinical performance and clinical time to restore occluso-proximal cavities in primary molars withbulk-fillresin and conventional resin. A total of 140 class II restorations in primary molars of 65 participants (mean age of 6.7 + 1.5) were placed in two random groups:bulk-filland conventional resin. The restorations were evaluated using FDI criteria at the baseline, 6-month, and one year by a single calibrated examiner, and the clinical restorative time was measured with a digital timer. The success and survival of the restorations were evaluated with Kaplan-Meier graphs. The log-rank test compared the curves. Differences in restorative clinical time were compared using the Mann-Whitney U test. The level of significance was 5%. After one year, 115 restorations were evaluated. The success probability was 88.7% for Filtek Z350 XT and 85.9% for FiltekTM Bulk-fill, and for the survival probability, Filtek Z350 XT presented 90%, and FiltekTM Bulk-fill presented 93.7%. No significant difference was found between the success and survival curves (p=0.62), (p=0.51). The main reason for failure was marginal adaptation.Bulk-fillresinrequired 30% less time than the conventional resin (p<0.001).Bulk-fillresin presented similar clinical performance to the conventional resin and required less restorative clinical time. It is an option to restore class II lesions of primary molars.