Category: Laboratory Research
Award Category: Junior Scientist
Direct Laser Writing (DLW) Based Surface Texturing for Enhanced Adhesion Between Zirconia (3Y-TZP) and Resin Matrix Cement
Narayan Sahooa* (ilovsai@gmail.com) | Oscar Cavarlhoa | Mutlu Özcanb | Filipe Silvaa | Bruno Henriquesc
aCentre Microelectromechanical Systems (CMEMS), University of Minho, Guimarães, Portugal
bDivision of Dental Materials, Center for Dental and Oral Medicine, University of Zürich, Zürich, Switzerland
cCeramic and Composite Materials Research Group (CERMAT), Federal University of Santa Catarina, Florianópolis, Brazil
Objective: To evaluate the influence of direct laser writing (DLW) based surface texturing of zirconia (3Y-TZP) on shear bond strength (SBS) with resin-matrix cements.
Methods: Zirconia (3Y-TZP) green compacts received any of the two laser patterns: LD35 - Squared pattern lines 35 µm spacing (0.6 W,128 mm/s); LD10 - Squared pattern lines 10 µm spacing (0.06 W,256 mm/s) and sintered samples received one of the following: AS (As sintered), SB - Alumina (Al2O3) sandblasting or SC - silica (SiO2) coated alumina (Al2O3) blasting. Surface energy, surface roughness, wettability is evaluated for each group (n = 12/group). Treated samples from all groups were ultrasonically cleaned and cemented to resin-matrix cement using primers. The cylindrical shape cements bonded at the center of 3Y-TZP samples were either stored for 24 h at 37 ºC or thermocycled (5-55 ºC, 6000 cycles) and SBS was performed subsequently.
Results: The surface roughness was highest in DL35 (1.74 ± 0.06) and lowest by AS (0.40 ± 0.14). The lowest and highest contact angle (water) was produced by SC (27.30 ± 4.66) and SB (61.44 ± 2.97) respectively. The lowest and highest contact angle (Diiodomethane) was produced by LD10 (26.93 ± 2.85) and SC (36.76 ± 0.27) respectively. Surface free energy was highest for SC (65.30 ± 2.06) and lowest for SB (56.15 ± 1.19). The two laser groups: LD10 (9.16 ± 1.55) and LD35 (8.89 ± 2.18) produced higher SBS than SC (6.46 ± 1.84) and AS (2.47 ± 0.8). Thermocycling (TC) reduced the SBS of all groups. The highest SBS after TC was shown by LD35 (8.49 ± 2.02) and the lowest by SB (5.97 ± 2.43). The reduction in SBS was significant in SB whereas both the laser groups retained higher SBS than SB and SC, there was an increase of SBS in SC group after TC.
Conclusion: All the surface treatments increased SBS of the zirconia(3Y-TZP) surfaces with resin-matrix cement compared to AS.
Funding/Conflict of Interest: The authors declare that there is NO conflict of interest. This work was supported by Fundação para a Ciência e Tecnologia (FCT) through the grant 2021.07095.BD. Keywords: adhesion, shear bond strength, direct laser writing (DLW), surface modification, zirconia(3Y-TZP)
