Sintering and Crystallization of Phosphate Glasses by CO2‐Laser Irradiation on Hydroxyapatite Ceramics
Phosphate glasses in the 50CaO‐(50‐x) P2O5‐xTiO2‐1Al2O3
(x = 5–25 mol%) system were produced and irradiated with low energy density CO2 laser to melt and crystallize on a hydroxyapatite (HA) ceramic plate for dental filler applications. The laser with
10.6 μm of wavelength is easily absorbed by phosphate and hydroxy groups. The phosphate glasses containing ~15 mol% of titania strongly adhered to the HA plate surface through melting and sintering by the laser irradiation. The coatings after the laser irradiation
contained crystalline phases. There was no significant changes in the morphology of the coating containing 15 mol% of TiO2 on the HA plate even after soaking in 0.1 mM HCl
solution for 10 min. This coating was suspected to have good chemical durability. Powders of the glass or glass‐ceramic containing 15 mol% of TiO2 were soaked in distilled water to check their dissolution behavior over the
long term. Dissolution from the glass‐ceramic was much slower than those from the glass at all points.