Introduction: The effect of bleaching on tooth structure is the loss of interprismatic substance which causes prism irregularities and changes in enamel morphology such as increased porosity and demineralization. This can be stopped by encouraging remineralization if the pH is neutralized and there are enough calcium and phosphate ions in the oral cavity. One agent that can be used to help the remineralization process is nano hydroxyapatite (nHA) which is a bioactive and biocompatible material for the natural mineral enamel. This study aims to determine change in the percentage of porosity, calcium, phosphate and hydroxyapatite synthesized from blood clam shells (Anadara granosa) and CPP-ACP as a positive control. Material and methods: The research design was a pre-post test control group design. Six maxillary first premolars were cut to the CEJ with a size of 5x5x2 mm then 40% hydrogen peroxide was applied. The first group was applied nHA synthesized from blood clam shells and the second group was applied CPP-ACP. Determination the percentage of porosity, calcium, phosphate and hydroxyapatite was carried out before and after bleaching and after aplication of remineralizing agent. Results: The study showed an decrease the porosity, calcium, phospate and increase hydroxyapatite precentage after sampel was applied to the remineralizating material nHA synthesized from blood clam shells and CPP-ACP. Conlusion: nHA results of blood clam shell synthesis has the potential to be used as an enamel remineralization agent after in-office bleaching. Key words: Blood clam shell, Casein Phosphopeptide-Amorphous Calcium Phosphate, In-office bleaching, Nano Hydroxyapatite

Pulp Out, paste-contained jatropha sap, sidaguri roots, and melittin, has been studied to have potency used as an herbal-based devitalizing agent. Prior to clinical application, the toxicity of Pulp Out should be evaluated as it might leak from the cavity unintentionally and get into the digestive systems, which can cause either local or systemic effects. The present study aimed to evaluate the impact of Pulp Out application on periodontal and periapical tissue as well as acute toxicity in Wistar rats. The paste was inserted into the periapical tissue. After 7 days, the periapical tissue was isolated for histopathological evaluation. Pulp Out in an oral suspension of 50, 500 and 2500 mg/kg BW was administered. Autonomic nerve signs were observed intensively every 4 h as well as water and food consumption for 14 days. Biochemical, hematologic parameters and specific organs were evaluated. Therefore, considering the inflammatory lymphocyte cells, osteoblasts, and osteoclasts, Pulp Out is not toxic. The acute toxicity study revealed no treatment-related death was observed, indicating that LD₅₀ is greater than 2500 mg/kg BW. No significant difference statistically either in body weight, water or food consumption as was observed in autonomic clinical signs of treated groups when compared to the control. Similarly, biochemical and hematologic properties showed no significant difference compared to control. Histopathological, slightly hydrophilic degenerative was observed in all organs. In conclusion, Pulp Out showed low acute toxicity in Wistar rats.