Background: Current research aims to find alternatives to conventional methods for suppressing periodontopathogenic bacteria. Photodynamic therapy (PDT) could be a suitable treatment procedure of periodontal infections.Methods: In the present study, the PDT method was tested with two photosensitizers, chlorine e6 and BLC1010, in an experiment on beagle dogs. The animals were infected with Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn) in all subgingival areas. After infection, we observed clinical signs of gingival inflammation, including an increase of redness and bleeding on probing. Microbiological monitoring before and after treatment was performed using polymerase chain reaction (PCR). PDT was conducted with a diode laser with a wavelength of 662 nm using a power of 0.5 W and the photosensitizers.Results: The PDT procedure carried out with either of the photosensitizers caused a significant reduction in the clinical inflammation signs of redness and BOP, compared to the controls (laser only and no treatment). Furthermore, PDT with chlorine e6 caused a significant reduction in P. gingivalis‐infected sites, whereas there was a lack in suppression after PDT with BLC1010. F. nucleatum could hardly be reduced with chlorine e6, and only to a certain extent with BLC 1010 and laser only. In the control groups, the Pg‐infected test sites did not change.Conclusions: This study demonstrated that the photodynamic therapy using photosensitizer and a 662 nm laser light source is distinctly advantageous in reducing the periodontal signs of redness and bleeding on probing. The procedure also appears to significantly suppress P. gingivalis. J Periodontol 2005;76:1100‐1105.

Background: The purpose of this study is to clinically and microbiologically evaluate the effect of photodynamic therapy (PDT) as a full‐mouth procedure in Fusobacterium nucleatum–infected patients with periodontitis.Methods: In the present study, PDT is administered adjuvantly after scaling and root planing (SRP) to patients with localized chronic periodontitis (LCP). Twenty‐four patients, in whom only F. nucleatum was detected by baseline polymerase chain reaction (PCR) after SRP, were randomly assigned to PDT and control groups. PDT was carried out once as a full‐mouth disinfection in the test group. The control group was treated with the photosensitizer solution, but without laser irradiation. In all subjects, the clinical parameters plaque index, reddening, bleeding on probing (BOP), probing depth (PD), gingival recession, and clinical attachment level (CAL) were determined at the baseline examination and at 1, 4, and 12 weeks after PDT. Quantitative analysis of the F. nucleatum DNA concentration was performed by competitive PCR. All clinical indices were calculated for each test and control subject as were the median and interquartile range of each group.Results: In patients with LCP who received PDT treatment, significant reductions in reddening, BOP, and mean PD and CAL were observed during the observation period and with respect to controls. Four and 12 weeks after PDT, the mean PD and CAL showed significant differences from baseline values and from those of the control group. In the PDT group, 12 weeks after treatment, the F. nucleatum DNA concentration was found to be significantly reduced compared to the baseline level.Conclusion: The results of this study show that the adjuvant application of the described PDT method is appropriate to reduce periodontal inflammatory symptoms and to successfully treat infection with F. nucleatum.

(1) Background: Antimicrobial agents such as chlorhexidine (CHX) are commonly used in oral plaque control. However, sometimes those agents lack antimicrobial efficiency or cause undesired side effects. To identify alternative anti-infective agents, the present study investigated the antibacterial activity of all-fruit juices derived from blackcurrant, redcurrant, cranberry and raspberry on common oral pathogenic gram-positive and gram-negative bacteria (Streptococcus mutans, Streptococcus gordonii, Streptococcus sobrinus, Actinomyces naeslundii, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Enterococcus faecalis). (2) Methods: Antibacterial efficiency was evaluated by agar diffusion assay and in direct contact with bacteria in planktonic culture. Furthermore, cytotoxicity on human gingival fibroblasts was determined. (3) Results: Blackcurrant juice was most efficient at suppressing bacteria; followed by the activity of redcurrant and cranberry juice. Raspberry juice only suppressed P. gingivalis significantly. Only high-concentrated blackcurrant juice showed minimal cytotoxic effects which were significantly less compared to the action of CHX. (4) Conclusion: Extracts from natural berry juices might be used for safe and efficient suppression of oral pathogenic bacterial species.