Synthesis and characterization of calcium hydroxide from Indonesian limestone as endodontic intracanal medicament

Calcium hydroxide [Ca(OH)₂] has been the gold standard for endodontic medicament as inter-appointment dressing, due to its ability to act as antimicrobial agent and to promote hard tissue healing. The main mechanism of this material is the release of Ca²⁺ and OH^- ions through its vehicle, providing high alkaline pH. Indonesia, has many potential resources, namely limestone (CaCO₃), that can be utilized as raw material for Ca(OH)₂. The objective of this present study is to investigate the synthesis and characterization of Ca(OH)₂ from Indonesian limestone as an endodontic intra-canal medicament. Limestones were taken from Palimanan area in West Java, Indonesia. CaCO₃ was calcined at 900°C for 4h resulting CaO powder. CaO powder was mixed with distilled water using a rotary stirrer for 24h and produce Ca(OH)₂ paste. The Ca(OH)₂ paste was dried at 80°C, then crushed using a mortar and pestle to obtain Ca(OH)₂ powder. The powder samples were thus subjected for characterization by X-Ray Diffraction (XRD) and Fourier-Transform Infrared (FTIR) Spectroscopy. The XRD patterns revealed that the high peak of Ca(OH)₂ crystallinity was successfully achieved in this study. The FTIR spectroscopy also showed bands at 3640 cm^-1 which belongs to OH^- stretching vibration of the Ca(OH)₂. The results indicate that the synthesis of Indonesian limestone as Ca(OH)₂ by this method was attained. Indonesian limestone is a potential raw material that can be used as a precursor for synthesis of Ca(OH)₂ as an endodontic material.