Vertical and Horizontal Transmission of Streptococcus Mutans and Effective Factors: An In Vivo Study

Aim: The degree of vertical (intrafamilial) and horizontal (extrafamilial) transfer of Streptococcus mutans ( S. mutans) to a child shows differences according to cultures. The wrong care habits may result in transfer of S. mutans. The aim of this study was to determine the vertical and horizontal transmission of S. mutans to a child and effective factors. Materials and Methods: Mothers and kindergarten staff of 37 children aged between 4 and 5 years who initially started in two kindergartens (Group 1, n = 19; Group 2, n = 18) were included in this in vivo study according to 95% reliability and 80% theoretical power. Intraoral examination of mothers and children made according to the World Health Organization criteria (dmf-t/DMF-T) was done, following which mothers were asked to fill questionnaire forms including knowledge and attitudes of them about oral/dental health care. 1 mL saliva samples received from children/mothers/staff were examined microbiologically in order to isolate and quantify S. mutans. Arbitrarily primed polymerase chain reaction analysis was done to determine the genetic characteristics of S. mutans. All examinations were repeated to evaluate the horizontal transmission in the fifth month. Parametric tests ( t-test and two-way analysis of variance) were employed for comparison of the variables that meet the normality assumption and nonparametric tests (Mann–Whitney) were also used. Results: It was observed that there is a statistically significant correlation between mother DMF-T values and mother–child S. mutans similarity level ( P < .05). There is a statistically positive correlation between the habits of using a common fork, spoon, glass, and mother–child similarity level. Conclusion: Vertical and horizontal transfers occurred in Turkish families in order to prevent the transfer of S. mutans; wrong baby care habits that may lead to the transfer of S. mutans, which is the main factor in case of tooth decay, should be avoided.