Nickel chromium brackets and its effect on the oral microflora

Abstract

Nickel chromium brackets are the most common type of fixed orthodontic appliance used in our environment and may alter the oral microflora. Aim: This study aimed to determine the effect of nickel chromium brackets in orthodontic treatment on the oral microflora and to compare with a control group of dental students. Method: Thirty-eight randomly selected participants were divided into two groups. Group 1 was 19 orthodontic patients (OS) with anterior segment crowding. Group 2 were 19 normal dental students (DS) who served as a control group. Two samples of stimulated saliva were collected. The initial sample was collected before the placement of nickel chromium brackets (OS1) and the other 6 months after wearing the appliance in both arches (OS2) for group 1. Group 2 also had the initial (DS 1) and second samples (DS2) collected after a 6 month interval. The saliva was analyzed after being inoculated onto blood, chocolate and MacConkey agar plates which were incubated for 24 hours at 37 degrees C aerobically except chocolate agar, which was incubated in a candle extinction jar. Results: The results showed that Streptococcus viridans was the most prevalent microorganism and was isolated in 15 (79%), and 11 (57.9%), of groups OS1 and DS1 respectively. There was no statistical difference between both control groups OS1 and DS1 (p>0.05), and treatment groups OS2 and DS2 for Streptococcus viridans. There was a significant difference between DS1 with 7(36.8%) and OS1 with 2 (10.5%) for Staphylococcus aureus (p<0.05). Klebsiella pneumoniae was cultured in all groups except OS2. There was also no statistically significant difference between groups OS1 and OS2 and the control groups DS1 and DS2 for all the organisms cultured. There was no change in composition of bacteria between groups OS1, OS2 and DS1. Conclusion: There is no difference in the oral microflora between orthodontic patients and normal subjects and wearing nickel chromium brackets does not significantly alter the composition of the oral microflora.