Three-dimensional profilometric assessment of Er:YAG laser irradiated unsintered zirconia

Author(s)

Ferreira da Silva, Beatriz Togoro ^[1] ; Cesar, Paulo Francisco ^[2] ; de Freitas, Patricia Moreira ^[1] ; Palma-Dibb, Regina Guenka ^[3] ; Matos, Adriana Bona ^[1]

Affiliation

^[1] Univ Sao Paulo, Sch Dent, Dept Operat Dent, Av Prof Lineu Prestes, 2227, Cidade Univ, BR-05508000 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Sch Dent, Biomat & Oral Biol Dept, Av Prof Lineu Prestes, 2227, Cidade Univ, BR-05508000 Sao Paulo, SP - Brazil

^[3] Univ Sao Paulo, Ribeirao Preto Dent Sch, Dept Restorat Dent, Ave Cafe S-N, BR-14040904 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Journal of Materials Science; v. 51, n. 15, p. 7266-7275, AUG 2016.
• Web of Science Citations: 0

Abstract

This study evaluated the effects of different Er:YAG laser pulse width protocols on surface roughness, loss of volume of the material, and the step height formed of pre-sintered yttrium-stabilized tetragonal zirconia polycrystalline (Y-TZP) by three-dimensional profilometric assessment. Blocks of pre-sintered Y-TZP were cut providing 63 standard 5-mm-thick samples which were divided by surface treatment, as follows (n = 9): G50 (100 mJ/10 Hz/1 W-50 mu s); G100 (-100 mu s); G300 (-300 mu s); G600 (-600 mu s); G1000 (-1000 mu s); GTC (tribochemical silica coating); and GNC (untreated). After treated or not, samples were sintered according to the manufacturer's recommendations. Roughness, volume loss and step height were analyzed by 3D profilometric assessment with confocal laser microscopy. ANOVA and Tukey's test (p < 0.05) detected that irradiated groups showed increased roughness in the groups G50, G100, G300, and G600 when compared to GTC and GNC groups. The G1000 group showed a completely flat and unfavorable surface for retention. The groups G50, G100, and G300 showed great loss of volume and the step height formed, which can lead to a gap on the crowns. In G600 was observed satisfactory roughness with little loss of volume and the step height formed similar to GTC. Irrespective of laser protocol, any of the specimens showed the presence of cracks. It is suggested that the pulse width 600 mu s (G600) is the most suitable pulse width protocol as an alternative surface treatment, promoting micro-retention, with little loss of volume of material, comparable to silica coating treatment. (AU)

• FAPESP's process: 12/15141-6 - Screening Er:YAG (SSP) laser parameters to increase longitudinal adhesion to caries affected dentine
• Grantee: Adriana Bona Matos
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/13571-1 - Er:YAG laser pulse width influence in dentin and esthetic restorative materials
• Grantee: Adriana Bona Matos
• Support Opportunities: Regular Research Grants