Synthesis of hydroxyapatite from hard clams shell (Meretrix spp.) using hydrothermal method as a dental implant coating biomaterials

Biomaterials that can be used as coatings on dental implants are hydroxyapatites. One of the natural substances used in the synthesis of hydroxyapatite is the ale-ale shell, which has a substantial calcium content of 93,444%. The hydroxyapatite synthetic was carried out using a hydrothermal method that uses the calcium precursor (Ca) of the ale-ale shell and phosphate precursors (P) derived from (NH4)2HPO4, as well as NH4OH as a pH regulator. This research uses the influence variables of CaO/(NH4)2HPO4 concentration (0.67; 1.67; and 2.67) and pH (11, 12, and 13). The results of the FTIR analysis showed that the typical absorption peaks of hydroxyapatites are , OH-, and group absorptions. XRD analysis results showed the formation of major HAp peaks that correspond to ICDD data 01-072- 1243, with the highest peaks in succession appearing at angles 31,74; 31,67; and 31,64°. The crystal size is 35,25; 123,39; and 55,81 nm with degrees of crystallinity in sequence of 87,28; 91,67; and 95,09° and has a hexagonal crystal shape. Hydroxyapatite synthesis with ale-ale shell waste raw materials by hydrothermal method gives the best results at a concentration of CaO/(NH4)2HPO4 2.67-pH 13.