Statistical data from studies on the effectiveness of probiotics do not follow a normal distribution, as the literary findings have decisive results correlate because of the difficulty of controlling the variables in each study. Probiotics have been used as flora modulator in response to oral health. The apparent results are considered from some microbiological factors (individual biofilm) that insert in individuals more or less susceptible groups to caries, periodontitis and halitosis. Nevertheless it is noteworthy that the use and the potential of probiotics are arguably directly proportional to other health conditions. Among these the socio-economic conditions stand out, those are rarely covered by research of this nature. This study aimed to track down several scientific studies that link positive and negative factors about the action of probiotics on pathogenic microorganisms such as Streptococcus mutans and Candida albicans. The methodology consisted of the advanced search in databases such as Pubmed, Scielo, Lilacs and various universities platforms, using the Mesh Terms: Probiotics, Streptococcus mutans, Candida albicans, Oral Pathology Microorganisms, Oral Health and Probiotics and Effects of Positive and Negative Oral probiotics. For the probiotic to be able to exert an anticariogenic effect; primarily the bacteria must be capable of adhering to the dental surface; second, it must become part of the biofilm; and finally, it must compete with cariogenic bacteria reducing the level of colonization of these. It was concluded that through pre-clinical and clinical action of probiotics on pathogenic microorganisms there is still enlightening results about the efficacy of probiotics, making it necessary to increase randomized multicenter studies.