Effectiveness of Titanium Tetrafluoride on the Bond Strength of Composite Cement to Titanium

To assess the influence of titanium tetrafluoride (TiF4) solution on the adhesion of composite cement to commercially pure titanium (cp Ti).

cp Ti plates with dimensions of 30 mm × 8 mm × 1.5 mm were machined and polished. The specimens were divided into seven groups according to the surface treatment as follows: group 1: control (machined); group 2: sandblasted with 110 µm Al2O3; group 3: hydrofluoric acid (HF); group 4: TiF4 (5%-5 min); group 5: TiF4 (5%-10 min); group 6: TiF4 (10%-5 min); and group 7: TiF4 (10%-10 min). One type of composite cement (Multilink Speed) was applied to each group for assessing the bond strength using strain energy release rate (G-value, J/m2) test. SEM analysis and surface roughness evaluation of cp Ti were carried out after treatment. The debonded specimens were examined with a stereomicroscope and SEM. Data were analyzed by the Kruskal-Wallis and Dunn's multiple comparison tests. Statistical significance was set at the 0.05 probability level.

All the tested groups showed significantly higher bond strengths compared with the control group (p < 0.05). Surface treatment of cp Ti with TiF4 (10%-10 min) showed higher bond strength compared with sandblasting and HF groups (p < 0.05). Surface topography of treated cp Ti showed alterations in surface roughness and morphology.

Adhesion between composite cement and cp Ti could be improved by using TiF4 (10%-10 min) solution prior to composite cement application as an alternative technique to sandblasting and HF.