ABSTRACT
Introduction: The present study aimed to examine changes insubgingival microbiota and clinical parameters before and afterplacement of bracket.Methods: Clinical parameters such as plaque index (PI),probing depth (PD), bleeding on probing (BOP), clinicalattachment level (CAL), and gingival index (GI) were recorded.Additionally, subgingival microbial samples were collected from30 individuals aged between 13 and 25.A total of 15 individualsas the control group were matched in terms of age and sexwithout needing orthodontic treatment using specific primers.Furthermore, SYBER Green Real-Time PCR was conducted todetermine bacterial flora in stored samples. All the mentionedprocedures were reexamined in the experimental and controlgroups three months after band and bracket bonding. Adescriptive analysis was conducted, and paired t-test andWilcoxon test were employed for differences between thegroups (P<0.05).Results: No changes in the level of clinical attachment wereseen, but scores for plaque index, bleeding on probing andgingival index increased 3 months after placement of bracketin the experimental group (P<0.05). P. nigrescence in theexperimental group increased after placement of bracketscompared to the control group, but P. gingivalis and T.Denticola proportions increased.Conclusions: Fixed orthodontic appliances may raise thegrowth of periodontopathogenic bacteria and consequentlyleads to gingival inflammation without destructive effect ondeep periodontal tissues.