Mechanical potential of the association of different treatments with the deposition of films by plasma enhanced chemical vapor deposition on the zirconia surface

Author(s)

Sandro Basso Bitencourt

• Document type: Doctoral Thesis
• Press: Araçatuba. 2021-06-15.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Odontologia. Araçatuba
• Defense date: 2021-06-02
• Advisor: Aldiéris Alves Pesqueira

Abstract

To characterize the zirconia (Y-TZP) surface submitted to different surface treatments (with and without plasma associations) and to evaluate the shear bond strength (SBS) with the veneering ceramic (VC) after different aging methods. 301 3Y-TZP specimens (IPS e.max ZirCAD) were fabricated and distributed into 7 groups (n=43): Group C (control): no treatment; Group Al: airborne abrasion with 27 µm Al2O3 particle; Group L: liner; Group P: plasma; Group Al+L: airborne abrasion + liner; Group Al+P: airborne abrasion + plasma; Group P + L: plasma + liner. The Y-TZP surface was characterized by SEM, EDS, AFM, surface profilometry, and surface-free energy (SFE). XRD was used to verify the crystal structure after each surface treatment performed. SBS between Y-TZP and the veneering ceramic was verified after three aging protocols: initial, after hydrothermal aging (autoclave for 5h), or thermal fatigue (30,000 baths - 5-55°C). One- (profilometry and SFE) and two-way ANOVA (SBS), and Tukey’s HSD test were used as statistical analysis. For the plasma groups, a homogeneous and a full surface coverage was observed on SEM and AFM, with globular formation. Peaks of Si were found for Al, L, Al+L, and P+L groups. Roughness was lower for groups C, P, and Al+P. For SFE, the highest values were found when the liner was applied (>74.59 nm/Nm). The highest monoclinic content was observed for Al+L (6.96%) and Al+P (5.86%). For the initial period, group Al and P+L presented the lowest SBS values (< 5.85 MPa; P>0.331). After hydrothermal aging, groups L, P, and P+L presented the highest SBS values (> 8.25 MPa; P<0.001). After thermal fatigue, P, L, Al+L, and Al+P groups had the highest SBS values (> 6.35 MPa; P<0.001). Changes in Y-TZP topography and the SBS with the VC were observed, according to treatments performed. Plasma treatment improved SBS and did not cause phase transformation. (AU)

• FAPESP's process: 17/13933-6 - Mechanical potential of the association of different treatments with plasma enchanced chemical deposition on zirconia surface
• Grantee: Sandro Basso Bitencourt
• Support Opportunities: Scholarships in Brazil - Doctorate