Banca de DEFESA: HELENA NOBREGA ALMEIDA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : HELENA NOBREGA ALMEIDA
DATE: 22/07/2025
TIME: 08:30
LOCAL: DEAPRTAMENTO DE ODONTOLOGIA - AUDITÓRIO
TITLE:

Effect of different surface treatment protocols on bond strength for repair of 3d printed resins with composite resin: in situ study.

KEY WORDS:

CAD/CAM. Shear bond strength. Surface treatment. Microbiology

PAGES: 70
BIG AREA: Ciências da Saúde
AREA: Odontologia
SUBÁREA: Clínica Odontológica
SUMMARY:

Objective: To evaluate the effect of different surface treatment protocols and in situ aging (IS) on the repair bond strength of 3D-printed resins with composite resin, as well as to analyze the influence of different surface treatments on the surface characteristics of restorative materials. Materials and Methods: A total of 369 blocks (6 × 5 × 2.5 mm) were fabricated, including 123 blocks of each restorative material (Nanolab 3D/WILCOS [NL], Smile Crown Plus/BEGO [SC], and TetricCAD/IVOCLAR [TC]). Of these, 270 samples were used for shear bond strength testing, while the remaining samples were reserved for complementary analyses. For in situ aging, 45 samples of each material were embedded in complete dentures worn for 60 days. The 135 aged and 135 non-aged samples were randomly assigned to three surface treatment groups (n = 15): (1) diamond bur + adhesive, (2) airborne-particle abrasion with Al₂O₃ + adhesive, and (3) silica coating + silane + adhesive. Composite resin cylinders (2.5 × 3 mm) were built on the treated surfaces. All 270 specimens were subjected to thermocycling (10,000 cycles between 5°C and 55°C). Shear bond strength was tested using a universal testing machine (INSTRON 3365, USA) at a crosshead speed of 1 mm/min. After failure, all samples were evaluated under a stereomicroscope (Nikon SMZ800) to analyze the failure mode. Additional samples of each material were prepared for surface analysis via scanning electron microscopy (SEM) of the treated surfaces (n = 1) and surface roughness evaluation using an optical profilometer (CCI MP, Taylor Hobson, UK) (n = 10). Shear bond strength (MPa) and surface roughness data were statistically analyzed by three-way ANOVA and Tukey's test (5%). Failure mode and surface analyses were evaluated descriptively. Results: Three-way ANOVA revealed that the factors “restorative material” (p = 0.0013) and “in situ aging” (p < 0.0001) were statistically significant, whereas “surface treatment” was not (p = 0.1391). The SC JaAd group (19.70 MPaᴬ) showed the highest bond strength, statistically similar to the TC CjSiAd (15.78 MPaᴬᴮ), NL PdAd (15.62 MPaᴬᴮ), SC CjSiAd (14.72 MPaᴬᴮᶜ), and SC JaAd-IS (14.66 MPaᴬᴮᶜ) groups. The lowest values were observed in TC JaAd-IS (9.28 MPaᴰ) and NL PdAd-IS (9.29 MPaᴰ). Adhesive failure was the most prevalent in all restorative materials (NL: 45%; SC: 34%; TC: 67%). Surface analysis (SEM) and roughness evaluation showed that JaAd and CjSiAd treatments led to greater topographical alteration in SC, while no statistically significant differences were found among the protocols for NL and TC. Conclusion: In situ aging significantly reduced the repair bond strength in NL PdAd and TC CjSiAd groups. For SC, both JaAd and CjSiAd were equally effective. PdAd proved to be an efficient, reliable, and clinically accessible option for NL. All surface treatments tested in TC showed clinically acceptable performance. Surface treatments modified the topography and roughness of the materials, with JaAd and CjSiAd producing higher roughness in SC, while NL and TC exhibited similar values across protocols. These findings highlight the importance of considering the specific properties of each substrate when selecting the repair protocol for CAD/CAM resin-based indirect restorations to optimize the longevity of the adhesive interface.

COMMITTEE MEMBERS:
Presidente - 1640419 - RODRIGO OTHAVIO DE ASSUNCAO E SOUZA
Interna - 1678126 - PATRICIA DOS SANTOS CALDERON
Externa à Instituição - NATHALIA RAMOS DA SILVA - ABO