Analysis of Mechanical Properties and Printing Orientation Influence of Composite Resin for 3D Printing Compared to Conventional Resin.

This study aimed to compare the flexural strength, surface roughness, and microhardness of a resin for three-dimensional (3D) printing and a conventional composite resin and to evaluate whether the printing orientation influences these properties. To evaluate the flexural resistance, test specimens were produced and divided into four groups: three groups of resins for 3D printing with inclinations of 0°, 45°, and 90° and one group of conventional composite resin. Forty discs were produced and subjected to a sandpaper-polishing sequence, and the surface roughness was measured using a roughness meter.

Does the application of dimethyl sulfoxide improve resin bonding to eroded dentine? Four-year in vitro evaluation.

Objective: To evaluate the effect of dimethyl sulfoxide (DMSO) on the microtensile bond strength (µTBS) and nanoleakage (NL) of universal adhesives on eroded dentine, immediately and after four years of water storage.

Methods: Sixty-four sound human molars were distributed into 16 groups according to (1) Dentine surface (sound and eroded dentine); (2) dimethyl sulfoxide application (with or without); (3) Application mode (etch-and-rinse or self-etch) and (4) Storage time (immediate and four years). One mild universal adhesive was used (Scotchbond Universal).