Abstract The objectives of this double-blind randomized clinical trial were to compare (a) the clinical times and (b) the occurrence and severity of postoperative sensitivity, of posterior restoration that used a universal adhesive, in a self-etch or selective enamel-etching technique, along with incremental or bulk-fill composites (presented in syringes or capsules).

A total of 295 posterior restorations were placed according to the following groups:

SETB - self-etch/bulk-fill in syringe; SETC - self-etch/bulk-fill in capsules; SETI - self-etch/incremental; SEEB - selective enamel-etching/bulk-fill in syringe; SEEC - selective enamel-etching/bulk-fill in capsules; and SEEI - selective enamel-etching/incremental. Clinical time was assessed by a reason (s/mm3) between the total volume of resin inserted and the total time required to perform the restorations. Postoperative sensitivity was evaluated using two scales (Numeric Rating Scale and Visual Analogue Scale). Mean clinical time results, analyzed by Wald's Chi-square, showed significant statistical differences among all groups (p<0.001), indicating that the restorative strategy affected the time required for the restoration. A generalized estimating equation model statistical analysis, performed to compare postoperative sensitivity, showed that neither the restorative technique, the adhesive strategy nor the presentation mode of the bulk-fill composite affected the overall risk of postoperative sensitivity (4.06 [2.22-6.81]). The use of bulk-fill composite, presented in capsules or syringes, is less time consuming and does not increase the risk or intensity of postoperative sensitivity relative to the traditional incremental technique.