Detection and Elimination of the Porphyromonas gingivalis Biofilms

Objectives: Prevotella intermedia possess metabolic pathways to derive iron ions from erythrocytic components. During this metabolic process, porphyrin is produced in the biofilm. Porphyrin absorbs visible blue light and emits red fluorescence at 630 nm. Based on this mechanism, detection devices have been developed. In the present study, we used a fluorescence detector to investigate the biofilms and developed an elimination method of this biofilm. Methods: QLF and Penscope were used for a fluorescence detector of biofilm. Dental Drug Delivery System (3DS) was used for an elimination method of this biofilm. Results: Using a fluorescence detector, we analyzed the role of P. intermedia in the development of Porphyromonas gingivalis biofilm. These bacteria were cultured on blood agar and exposed to visible blue light at 405 or 409 nm. Only the colonies of P. intermedia emitted red fluorescence. In the in vivo analysis, relative fluorescence unit (RFU) of biofilms correlated strongly (R²=0.80) with the number of P. intermedia. RFU of biofilm tended to increase with an increase of the number of P. intermedia or P. gingivalis, while no correlation was found between RFU and the number of T. forsythia. Although P. gingivalis did not emit fluorescence, a strong positive correlation was observed between biofilm RFU and the number of P. gingivalis at R²=0.78, as well as between the numbers of P. intermedia and P. gingivalis at R²=0.91 in biofilms. Both P. intermedia and P. gingivalis were isolated in 9 of 16 subjects, although P. intermedia alone was isolated from 6 subjects. The 3DS method was applied to eliminate the pathogenic biofilm. The effectiveness of 3DS was assessed by FITC. Conclusion: The results suggest that P. intermedia may be associated with the colonization of P. gingivalis . P. gingivalis biofilms were able to remove by the 3DS methods.