Changes in subgingival microflora after placement and removal of fixed orthodontic appliances

Abstract

Introduction. The placement of fixed orthodontic appliances may lead to increased plaque accumulation and changes in subgingival microflora. Objective. The aim of this study was to examine the changes in frequency of subgingival microflora that occur after placement and removal of fixed orthodontic appliance using polymerase chain reaction (PCR). Methods. This study included 33 orthodontic patients, who were divided into two groups. Subgingival plaque samples were collected from the right upper incisor (U1) and right upper first molar (U6). In group A, the samples were taken three times: before placement appliance (T1), after one month (T2), and after 3 months (T3). In group B the samples were also taken three times: before appliance removal (T1), after one month (T2), and after three months (T3). PCR method was used to determine the presence of P. gingivalis, A. actinomycetemcomitans, T. forsythia, and P. intermedia. Results. In group A the frequency of P. gingivalis showed statistically significant decrease at U1 (p=0.049) and U6 (p=0.008), from T1 to T2, and at U1 (p=0.048) from T1 to T3. In group B only the frequency of T. forsythia showed a statistically significant decrease, at U6 (T1 vs. T2, p=0.004; T1 vs. T3, p=0.0003). Regarding other analyzed bacteria, changes in the presence were noticed but no statistical significance was found. Conclusion. Placement of fixed appliances may have an impact on subgingival microflora, but in the first months after the placement and removal of the appliance changes were not significant, probably due to good oral hygiene. [Projekat Ministarstva nauke Republike Srbije, br. 175075]

The microbial changes in subgingival plaques of orthodontic patients: a systematic review and meta-analysis of clinical trials

“…Three studies [19–21] reported the microbial changes before and after appliance removal. Two studies [22, 23] analysed the effects of both appliance placement and removal on microbial changes. For a long-term observation, three studies [6, 15, 18] reported at least a 6-month observation period.…”

“…Three studies [6, 16, 22] quantitatively evaluated the difference of the frequency of Aa in the first molar before and after appliance placement. The change was not statistically significant (odds ratio (OR), 0.82; 95% confidence interval (CI), 0.21–3.23; P  = 0.77) according to the meta-analysis (Fig.…”

“…2a). From a qualitative perspective, six studies [6–8, 15, 16, 22] described the changes in Aa at the beginning of orthodontic treatment. Five of the six studies reported that the frequency of Aa was not significantly changed following the appliance placement.…”

“…2b) from three studies [6, 16, 22] showed that the frequency of Pg in the first molar did not significantly change (OR, 0.97; 95% CI, 0.24–3.89; P  = 0.97). From a qualitative perspective, six studies [4, 6, 7, 16, 22, 23] focused on Pg changes after orthodontic appliance placement. Among these, two studies [6, 16] found no significant change in Pg , but two [22, 23] showed a significant reduction in Pg and the remaining two [4, 7] reported a significant increase.…”

“…2c) of three studies [6, 16, 22] that analysed the first molar showed that there was a significant increase (OR, 0.27; 95% CI, 0.13–0.55; P  = 0.0004) in the frequency of Tf after appliance placement. From a qualitative perspective, there were five studies [4, 6, 7, 16, 22] focusing on Tf changes after orthodontic appliance placement. Two studies [4, 6] found a significant increase in Tf detection rates.…”