Streptococcus mutans are oral bacteria that have the most role in developing dental caries. S. mutanscan form colonies and biofilms through adhesion mechanisms on the tooth surface. The use of chitosan as an antimicrobial material has been widely developed in dentistry, especially on the nanoscale, because nanomaterials can spread quickly throughout the biofilm structure. The use of hydroxyapatite (HAP) in conservative dentistry has been developed to protect teeth from S. mutans. This research aims to see the ability of nano chitosan hydroxyapatite (KNHP), if combined in gel form, does it prevent S. mutansfrom forming biofilms on the enamel surface. The research material was S. mutansserotype c and saliva collected from a volunteer. The biofilm mass profile was determined on the surfaces of teeth implanted on acrylic resin and incubated for 24, 48, and 72 hours, then observed under a counter colony lens. Determination of S. mutans CFU after interacting with nano chitosan hydroxyapatite for 24, 48, and 72 was then examined with spectrophotometry at a wavelength of 610 nm OD value of 0.08-0.1, which is equivalent to 0.5 McFarlan (1.5x 108). Then the determination of the interaction power of KNHP and HAP with S. mutanswas done by UV / VIS with a wavelength of 250-600 nm. The results showed that the mass profile of biofilms at 24 hours still showed colony growth after being given KNHP and HAP, whereas, at incubation times at 48 and 72 hours, there was no S. mutans growth. The interaction between KNHP and S. mutans with UV-VIS at 24, 48, and 72 hours incubation time has higher interaction power than HAP.

Keywords : Biofilm, Nano chitosan hydroxyapatite, Streptococcus mutans