Recuento de Unidades Formadoras de Colonias de Streptococcus mutans en pacientes con diferentes tipos de aparatología ortodóntica

Abstract

Introduction: The use of metal or metal-free orthodontic appliances has been reported in dental literature for promoting the accumulation of biofilm in the oral cavity and increasing bacterial counts of Streptococcus mutans which can eventually lead to the development of dental caries. However, there are limited amounts of studies that seek to establish the effects and variations caused by the interaction between orthodontic appliances (metal, non-metal, and the absence of), saliva, and oral microbes. Aim: To determine the Colony Forming Units (CFU) count of Streptococcus mutans in subjects with and without fixed orthodontic appliances through salivary samples while simultaneously measuring the oral and salivary pH of each participant. Methods: An observational cross-sectional study was carried out using convenience sampling and dividing 21 subjects into three groups (metal, non-metal and appliance-free), all of who were over the age of 18 years old, healthy, non-smokers, lacked any type of removable oral appliances and had not been under antibiotic treatment in the previous three months. The following variables were then evaluated: sociodemographic variables (sex, age, occupation, socioeconomic status), oral care habits (daily brushing frequency, and use of floss and mouthwash), and variables specific to the study (oral and salivary pH, presence and type of fixed orthodontic appliances, and the CFU count of S. mutans). Salivary samples were collected in the Basic Sciences Laboratory and the data obtained was analyzed using the Anova, Kruskal Wallis, Student t and Mann-Whitney U tests in the statistical software package Stata I/C version 14.0. All participants voluntarily agreed and signed an informed consent document. Results: Fourteen (66.7%) women participated, the average age was 20.4 ± 2.2 years, and the socioeconomic status four was the most frequent across all groups, although no statistically significant difference was found (p = 0.649). The group without fixed orthodontic appliances presented the highest CFU count of S. mutans; Mdn: 56.0 x 103 (IQR: 9.2 x 103 - 75.5 x 103) (p=0.9047). Regarding the oral pH, there was no statistically significant difference found (p=0.3397); however, after analyzing the salivary pH, a statistically significant difference was observed, with the metallic orthodontic appliances group presenting the lowest pH level (p=0.0427). Conclusions: The salivary pH of the participants with metallic appliances was lower, in other words, more acidic compared to the non-metal and appliance-free groups. Although no statistically significant difference was found between the groups and the CFU count of S.mutans, additional studies are required to further investigate this variable in subjects without orthodontic appliances and those with metal and metal-free appliances.