Efeito do tratamento de superfície na resistência de união entre resina impressa para base protética e material reembasador

Abstract

The objective was to evaluate the effect of surface treatment on the bond strength of denture base resin to reline material. Bar-shaped specimens (75x10x10mm) and square-shaped specimens (10x10x3mm) were fabricated using denture base resin (Prizma 3D Bio Denture). The bars were sectioned, and 3 mm from their center was removed to accommodate the reline material (Ufi Gel SC). The specimens underwent 3 surface treatments: no treatment (NT), monomer application (M), and 50µm aluminum oxide sandblasting (S). The bars were subjected to tensile bond strength testing (n=15), and the squares underwent roughness analysis (Ra) and wettability assessment (n=15). Failure modes and interface surfaces (denture base/reline material) were examined using light microscopy and scanning electron microscopy, respectively. The surface treatment did not affect the bond strength (MPa) (NT: 1.60±0.58; M: 1.69±0.38; S: 1.26±0.42), with predominance of mixed failures for all three treatments. Sandblasting resulted in higher roughness (µm) (NT: 0.13±0.04; M: 0.21±0.10; S: 2.45±0.63), while monomer application led to a reduction in contact angle (º) (NT: 116.14±7.18; M: 102.85±8.27; S: 114.36±7.34). The different surface treatments evaluated did not significantly increase the bond strength between the denture base resin and the reline material. Analysis of failure modes revealed predominance of mixed failures in all groups, indicating effective bonding between the denture base and the reline material regardless of the surface treatment applied. Regarding surface characteristics, sandblasting with 50µm aluminum oxide significantly increased roughness compared to the other treatment groups, while monomer application resulted in a decreased contact angle, indicating higher surface wettability.