Clinical evaluation of salivary periodontal pathogen levels by real-time polymerase chain reaction in patients before dental implant treatment.

OBJECTIVE: Periodontal pathogens in dental plaque are the main causative agents of periodontitis and peri-implantitis. Detection of the presence of such periodontal pathogens early would serve as a useful tool in the diagnosis and treatment of this disease. Therefore, the purpose of this study was to investigate whether the periodontal pathogen levels in saliva were correlated with the periodontal status of patients receiving implant treatment. MATERIALS AND METHODS: A total of 291 patients visiting Tokyo Dental College Chiba Hospital were divided into four groups: a no-periodontitis (np) group, a mild-periodontitis (mip) group, a moderate-periodontitis (mop) group, and a severe-periodontitis (sp) group. The levels of the following five periodontal pathogens in saliva were evaluated using real-time polymerase chain reaction: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Treponema denticola, and Prevotella intermedia. RESULTS: The levels of P. gingivalis and T. forsythia were significantly higher in mop group than in np group (P < 0.05). The levels of all periodontal pathogens tested except A. actinomycetemcomitans were significantly higher in sp group than in np group (P < 0.05). CONCLUSION: The detection levels of the periodontal pathogens targeted in saliva samples were correlated with the periodontal status. This suggests that using saliva to screen for periodontopathic bacteria offers an easier-to-use clinical tool than the paper point method in the diagnosis and treatment of periodontitis and peri-implantitis.

Influence of thin carbonate-containing apatite coating with molecular precursor method to zirconia on osteoblast-like cell response.

The influence of a thin carbonate-containing hydroxyapatite (CA) coating to tetragonal zirconia polycrystal (TZP) on osteoblastlike cell response was investigated. TZP disks were subjected to blasting and acid etching. Thin CA coatings were deposited by the molecular precursor method (TZP-CA). Initial cell adhesion of mouse osteoblast-like cells MC3T3-E1 was enhanced, and marked progress of actin filaments was observed on TZP-CA compared to on TZP. After 3, 5 or 7 days, cell proliferation on TZP-CA was significantly higher than that on TZP. Alkaline phosphatase activity was slightly lower on TZP-CA than on TZP at 7 days, and no difference was observed at 14 or 21 days. At 28 days incubation, collagenous fibers with mineral precipitants accompanied by phosphorous and amino groups were observed. These results indicate that thin CA coating with molecular precursor method offers promise as a means of enhancing cell response, particularly initial adhesion and proliferation of MC3T3-E1 cells.