Real-Time quantitative PCR for porphyromonas gingivalis in orthodontic patients

Objective Using real-time quantitative polymerase chain reaction (PCR) in orthodontic patients,and to investigate the effect of fixed appliance on the proportion of Porphyromonas gingivalis in total bacteria in subgingival plaques.Methods 30 patients with fixed appliance over 6 months were randomly selected as experimental group,and 30 without the appliance comprised as control group.Then examine the clinical indexes (Plaque index PLI,Sulcus bleeding index SBI,Probing depth PD) and the proportion of P.gingivalis in total bacteria in subgingival plaques,then find the difference between two groups.Results The results showed that there was significant difference statistically (P＜0.05) in PLI between the experimental (1.60±0.58) and the control group ( 1.09 ± 0.72).There was significant difference statistically (P＜0.001) in PD between the experimental (2.72±0.64) mm and the control group (2.13±0.18) mm.SBI had no significant difference (P=0.78) between two groups.And the proportion of P.gingivalis in total bacteria in subgingival plaques,in experimental group (0.45％ ± 0.07％) were more significant than that in control group (0.05％ ±0.01％) (P＜0.0001).Conclusions Fixed orthodontic appliances caused the increasement of the proportion of P.gingivalis in total bacterias in orthodontic patients,we can find the variation through real time quantitative polymerase chain reaction. Key words: Fixed orthodontic appliances; real-time quantitative PCR; Porphyromonas gingivalis