Fabrication and characterization of HA-oyster shell based on biopolymer - propolis as an agent of dental enamel remineralization material

This study aims to make gel composites by synthesizing and characterizing hydroxyapatite (HA) from oyster shell ( Crassostrea gigas ) as an essential ingredient for remineralization gel in teeth. The method used to synthesize HA is the precipitation method. HA is synthesized with a variation of calcination for 8 h at 1000 °C and aging time for 24 h to get the best result. The size of the HA crystal obtained is 14 ± 4 nm, with a degree of crystallinity of 91.54%. The result of the HA-oyster shell is used to synthesize gel composites. The gels used as parameters are composition variations: basis gel (basis gel as a negative control), HA gel, propolis gel, and HA-propolis gel. The essential ingredients of oyster shell, HA, and composite gels are treated by physicochemical tests in SEM , XRD , and FTIR characterization. The gel composites are treated using antibacterial tests with Streptococcus mutants, Streptococcus sanguinis, and Lactobacillus acidophilus . The antibacterial test aims to determine the inhibition of bacteria that cause caries in teeth. The best antibacterial test results are found in HA-propolis gel with the inhibition zone diameter of S.Mutants 22 ± 0.2 mm, S. Sanguinis 22 ± 0.3 mm, and L.Acidophilus 21 ± 0.2 mm. In addition to the antibacterial test, the gel was treated with a feasibility test to determine the viability of viable cells ( MC3T3-E1 ) when incubated for 48 h. The MTT test shows that the results of the HA gel sample gave significant cell growth, which was 92.80% at the low concentration. The physicochemical, antibacterial, and MTT (Viability) test results confirm that the HA-propolis gel composite could potentially improve dental enamel caries with the remineralization process.