Objective This study aimed to discover the effects of hot hydrochloric acid combined with heating on titanium-ceramic bonding strength. Methods Thirty-six industrial pure titanium TA2 test samples were randomly dividedinto four groups, with each group containing nine samples. One of the four groups was the control group with no treatment, and the other three were separately treated with 5%, 15%, and 25% boiling hydrochloric acid for 40 min. After cooling, the samples were placed in a porcelain fused to metal furnace up to 760 ℃ for 1 min. Titanium-porcelain specimens for bonding strength test were prepared. The titanium sample sections were observed with a field-emission scanning electron microscope. The elements’ transmigration in the titanium-ceramic interface was analyzed by energy-dispersive spectroscopy, and titanium-ceramic bonding strength was measured by the three-point bending method. Results The thickness of the oxide and reaction layers gradually increased with increased hydrochloric acid concentration. Among the four groups, the titanium-ceramic bonding strength of the 15% hydrochloric acid group was the strongest, followed by that of the 25% group and that of the 5% group. The titanium-ceramic bonding strength of the control group was the weakest. Conclusion Hot hydrochloric acid combined with heating treatment can improve titanium-ceramic bonding strength. Within the limits of the present study, the 15% hydrochloric acid treatment had the most obvious effect.
