Non-Thermal Plasma and Ho: YAG Laser Surface Conditioning: Effective Alternatives to Sandblasting for 3Y-TZP Zirconia-Composite Repair Bonding

Abstract

Objective: Evaluating the impact of surface conditioners, i.e., non-thermal plasma (NTP), Ho: YAG (Holmium: yttrium aluminum garnet crystal laser and Low-level laser therapy (LLLT) using Indocyanine green (ICG) on the surface topography, surface roughness (Ra) and repair bond strength (RBS) of 3% yttria-stabilized tetragonal zirconia (3Y-TZP) implant superstructure to composite.

Methodology: The present lab-based study was approved by the ethical board of King Saud University under registration # FC-91-2026. The duration of the study was one month. Sixty-four 3Y-TZP discs were sectioned from ready-made zirconia. Subsequently, samples were randomly divided into four groups. Group-1: SB, Group-2: NTP, Group-3: Ho: YAG laser and Group-4: LLLT-ICG. Ra and surface topography were evaluated using profilometry and SEM, respectively. Repair of the zirconia superstructure was performed using a composite and samples were artificially aged. A universal testing machine and stereomicroscope were used to assess SBS and fracture patterns. ANOVA and post-hoc Tukey were used to compare data (p< 0.05).

Results: Group-3 (Ho: YAG laser) showed the maximum roughness value (1209.42 ± 0.097 µm) and bond strength (11.43±0.12 MPa), while Group-4 (LLLT with ICG) showed the lowest Ra (679.78±0.069µm) and bond strength (6.87±0.10 MPa).

Conclusion: Holmium: yttrium aluminum garnet crystal and non-thermal plasma can be used as a suitable alternative to sandblasting, as it augments the surface roughness and repair bond strength of 3Y-TZP to the composite.