Surface characteristics of resin composite cores and bond strength to CAD/CAM resin matrix glass-ceramic restorations after different treatment protocols

• Published in: Odontology 2024-12
• Main Authors: Pereira, Leandro Maruki, de Melo, Bárbara Inácio, Netto, Verena Paula Stern, Bernardes, Paola, Raposo, Luís Henrique Araújo, Prudente, Marcel Santana, das Neves, Flávio Domingues
• Format: Article
• Language: English
• ISSN: 1618-1255; 1618-1255
• DOI: 10.1007/s10266-024-01034-9

The purpose of this study was to evaluate the impact of various mechanical surface treatments on the surface roughness and microtensile bond strength (µTBS) of aged composite resin cores bonded to CAD/CAM restorations. Composite resin specimens (Filtek Z350 XT, 3M-ESPE/Solventum) were thermally aged and subsequently divided into four groups (n = 36) according to surface treatments: UI-cleaning with ultrasonic diamond tip; AO-sandblasting with 50 µm Al O ; DB-cleaning with diamond burs; and CG-positive control group, without aging or surface treatment. Surface roughness was assessed using a profilometer and interferometer, with measurements taken on both sides of each specimen (n = 12). The surface characteristics were further analyzed through scanning electron microscopy (SEM) (n = 12). In addition, PMMA blocks were temporarily cemented (n = 12) onto the resin blocks, and after surface treatments, resin matrix glass-ceramic blocks were adhesively luted with dual-cure resin cement (RelyX Ultimate, 3 M-ESPE/ Solventum, St. Paul, MN, USA) to the resin composite substrates. The CG specimens were adhesively luted to the indirect restorations without temporary restorations or surface treatment. After luting, the specimens were sectioned and tested for µTBS. The results (p = 0.05) from the profilometry and interferometry analyses indicated the highest surface roughness values for the DB group, followed by AO, UI, and CG. SEM analysis revealed marked morphological differences among the groups. Regarding µTBS, the GC specimens (25.78 ± 5.70 MPa) and UI specimens (25.56 ± 11.36 MPa) exhibited statistically similar values, which were superior to those of the AO (12.25 ± 4.34 MPa) and DB (13.16 ± 5.59 MPa) groups (p