A novel resorbable α-calcium sulfate hemihydrate/amorphous calcium phosphate bone substitute for dental implantation surgery

The purpose of this study was to prepare resorbable α-calcium sulfate hemihydrate/amorphous calcium phosphate (α-CSH/ACP) bone substitute with a resorption period of 3–6 months specifically designed for dental implantation surgery. A one-pot process was used to manufacture α-CSH and ACP. Granular particles of α-CSH/ACP (60/40) with diameters of 420–840 μm were prepared. In dissolution test, both α-CSH/ACP (60/40) and CSD displayed rapid dissolution in the first 20 days, followed by a remarkably slow dissolution rate to reach weight retention plateaus of around 13.5% ± 0.7% and 40.5% ± 1.4% at 90 days, respectively. The in vivo study showed no adverse effects as a consequence of any of the implanted materials. After 3 weeks, the defects treated with α-CSH/ACP (60/40) showed more new bone formation (21.1%) than the empty control (13.6%) (p < 0.05). At 6 weeks, the treatment group with α-CSH/ACP (60/40) had more new bone formation (62.2%) than those with CSD alone (42.4%) and the empty control (40.1%) (p < 0.01). The complete in vivo resorption time within 3–6 months for α-CSH/ACP (60/40) was mathematically estimated by an extrapolation method. This biocompatible α-CSH/ACP (60/40) composite with a 3–6-month resorption period may be suitable for dental implantation surgery.