Abstract :
Based on the data from Basic Health Research (Riskesdas) in 2018, 57,6% of Indonesian society have dental and oral health problems. Dental caries are one of dental and oral health problems. Data from Balitbangkes of the Ministry of Health of the Republic of Indonesia in 2018, mentioned that in Indonesia, 29,8% of children aged 12 years had dental caries. Streptococcus mutans is the main cause of dental caries, which are the normal flora of the oral cavity. This study aimed to determine the effect of robusta coffee bean extract (Coffea canephora) in the Minimum Bactericidal Concentration (MBC) of Streptococcus mutans bacteria with dilution method. This study was an experimental laboratory study with post test only control group design consisting of positive control group, negative control group and robusta coffee bean extract group (Coffea canephora) with the variations of concentration are 10%, 20%, 30%, 40%, and 50%. The results of this study were robusta coffee bean extract (Coffea canephora) has the antibacterial effect to Streptococcus mutans bacteria with Minimum Bactericidal Concentration (MBC) 50%. In this concentration characterized by the unacquired growth of colonies of Streptococcus mutans bacteria in the inoculation media.