Structural characterization of a 3D-printed resin used in restorations subjected to surface treatments with different adhesive biomaterials. A preliminary study

Abstract

Objective: To analyze the surface structure of a resin used in 3D-printed restorations after treatment with different adhesive biomaterials, using scanning electron microscopy. Methods: Permanent Crown Resin (Formlabs, USA) was used in a 3D printer (Formlabs 3B Plus, USA) to produce 5 mm diameter discs. The experimental groups were: A) Resin without surface treatment (Control-RST), B) Resin with sandblasting/vaporization (v) (RCA), C) Resin with sandblasting/v + Ceramic Primer II + Optiglaze Color Clear glaze (GC-Corp., Japan) (RCP), and D) Resin with sandblasting/v + Composite Primer + Optiglaze Color Clear glaze (GC-Corp., Japan) (RRP). A structural surface analysis was conducted using SEM, and the thickness of the adhesive biomaterials and their interface with the resin was evaluated. The Mann-Whitney test was used for statistical analysis (p<0.05). Results: Control-RST and RCA exhibited homogeneous distribution of irregularly shaped particles, with sizes of 391.68 ± 144.08 nm and 443.79 ± 205.52 nm, respectively (p>0.05). RCP and RRP displayed circular-shaped particles measuring 58.51 ± 6.22 nm and 49.75 ± 6.07 nm, respectively (p>0.05). However, particle distribution was more homogeneous in RCP and more irregular in RRP. The thickness of adhesive biomaterials was 29.07 ± 7.0 µm for RCP and 12.94 ± 3.9 µm for RRP (p<0.05), and no interface was observed in either group. Conclusions: Preliminary results show no structural differences between the control resin and the sandblasted group. However, RCP exhibited a more homogeneous distribution and greater thickness of nanoscale circular particulates compared to RRP. These findings may help guide the selection of more effective surface treatments for these resins.