Antibacterial activity of Gel Nanohydroxyapatite-abalone as Remineralization Agent against Lactobacillus acidophilus, Streptococcus sanguinis, and Streptococcus mutans

Dental health issues in Indonesia require urgent attention, particularly periodontal disease and tooth decay, which can lead to cavities. Dental caries are multifactorial diseases influenced by bacteria, including Streptococcus mutans, Streptococcus sanguinis, and Lactobacillus acidophilus. The application of nano hydroxyapatite (n-HA) can be used as an alternative to help remineralize tooth enamel. Mouthwash, toothpaste, gum, and gel are generally used to reduce the risk of dental caries. This study chooses gel formulation because it is easy to apply and can increase the contact time between the active ingredient and tooth enamel. This work aims to investigate the antibacterial properties of gel nano hydroxyapatite abalone (gel n-HA Abalone) with concentration variations of 20,30, and 40 %.  The antibacterial analysis used the Kirby-Bauer disk diffusion method. This study analyzes the calcium/phosphate (Ca/P) molar ratio and the ability of the gel n-HA Abalone to inhibit the growth of key cariogenic bacteria. An increase in gel concentration was associated with an upward shift in the particle size distribution of the gel n-HA Abalone. Energy dispersive X-ray spectroscopy (EDS) showed that the Ca/P molar ratio of gel n-HA Abalone 40 % was 1.65, providing optimal ion availability for remineralization. Antibacterial testing revealed that the gel n-HA Abalone 40 % exhibited the most effective inhibitory activity, with inhibition zone diameters of 15.6 0.2 mm for Streptococcus mutans, 15.63 0.1 mm for Streptococcus sanguinis, and 15.27 0.3 mm for Lactobacillus acidophilus.  The gel n-HA Abalone 40  % can be a natural antibacterial agent for dental caries prevention.