Influence of Sputtering and E-beam Evaporation on Bond Strength of CP Ti-Ceramic
MetadataShow full item record
ABSTRACT: Statement of problem: At high firing temperatures, commercially pure titanium (CP Ti) forms a thick and irregular oxide layer that affects bonding with porcelain. Sputtering deposition of Chromium (Cr) or Zirconium (Zr)/ Zirconia (ZrO 2 ) may provide a protecting surface to minimize the formation of an oxide layer. This may promote adhesion of low fusing porcelain to CP Ti. Objective: The present study investigates the following: (1) The effects of surface treatment (Sputtering and E-beam evaporation) on the bond strength of low-fusing porcelain to CP Ti. (2) The effect of the deposited material (Zr or Cr) on enhancing the bond strength between porcelain and Titanium. Materials and methods: fifty plates of grade IV CP Ti were divided into 5 groups. Specimens were either sputtered or E-beam evaporated with either Zr or Cr, or not treated. Ti-22 Super Porcelain was applied on all specimens. Specimens were subjected to three-point bending test for evaluation of bond strength following ISO 9693. Debonding modes were determined by examination with scanning electron microscopy. Result: One-way ANOVA indicated significant differences in flexural strength among groups, (F 4,45 = 6.497, P < 0.05). Tukey HSD test revealed significantly higher bond strength for sputter Zr group (39.1 MPa) than all other groups except the control group. Two-way ANOVA indicated a significant main effect for surface treatment, (F 1,36 = 16.51, P < 0.005) and a significant interaction between surface treatment and material (F 1,36 = 12.95, P < 0.001). Conclusion: Within the limitation of this in vitro study, the following conclusions were drawn: 1. Surface treatment using Zr sputtering demonstrated significantly higher bond strength in comparison with the other treated groups. However, there was no statistically significant difference between this group and the control group. 2. There was no significant difference in bond strength between sputtering and E-beam evaporation as a method of deposition when Cr was used as a deposited material. 3. There was no significant difference in bond strength between Zr E-beam evaporated and either Cr group (Sputter Cr or E-beam Cr). 4. All specimens for all groups achieved a mean debonding strength/crack initiation strength greater than 25 MPa, and met requirements set by ISO 9693 for metal ceramic system.