Effects of egg yolk antibody against Porphyromonas gingivalis gingipains in periodontitis patients.

Porphyromonas gingivalis gingipains is suspected to be one of the most important causative agents of periodontitis. We postulated that the inhibition of gingipains may reduce the pathogenic nature of P. gingivalis. Anti-P. gingivalis egg yolk antibody (IgY-GP) was isolated from the yolks of hens immunized with purified gingipains. We applied IgY-GP gel subgingivally in periodontitis patients who harbored P. gingivalis in their subgingival flora. Five pairs of contralateral anterior single-rooted teeth were selected. One tooth in each contralateral pair was randomly treated with IgY-GP and subgingival scaling and root planing, whereas the other tooth was treated with SRP alone. The number of P. gingivalis bacteria was assessed by real-time PCR. Bacterial levels were expressed as the percentage of total bacteria. The IgY-GP group had a significant reduction in probing depth. BOP significantly decreased in the IgY-GP group compared to the control group at week 4. The levels of P. gingivalis significantly increased in the control group at week 4, whereas the reduction in the levels of P. gingivalis was sustained in the IgY-GP group. Within the limitations of the present study, IgY-GP was shown to be an effective immunotherapeutic agent in the treatment of periodontitis.

Low-intensity pulsed ultrasound stimulates osteogenic differentiation in ROS 17/2.8 cells.

There have been no studies investigating the effects of the mechanical stimulation provided by Low-intensity pulsed ultrasound (LIPUS) treatment on periodontal disease accompanying bone loss. LIPUS is known to accelerate mineralization and bone regeneration, but the precise cellular mechanism is unclear. Here, we investigated the effect of LIPUS on osteogenesis by examining the effect of LIPUS stimulation on cell proliferation, alkaline phosphatase (ALPase) activity, osteogenesis-related gene expression, and mineralized nodule formation in a rat osteosarcoma cell line. The cells were cultured in medium with or without the addition of LIPUS stimulation. The ultrasound signal consisted of 1.5 MHz at an intensity of 30 mW/cm(2) for 20 min for all cultures. LIPUS stimulation did not affect the rate of cell proliferation. ALPase activity was increased at day 7 of culture after LIPUS stimulation. Real-time PCR analysis indicated that LIPUS significantly increased the expression of mRNA for the transcription factors Runx2, Msx2, Dlx5, and Osterix and for bone sialoprotein, whereas the mRNA expression of AJ18 was significantly reduced. The mineralized nodule formation and the calcium content in mineralized nodules were markedly increased on day 14 of culture after LIPUS stimulation. Our study demonstrates that LIPUS stimulation directly affects osteogenic cells, leading to mineralized nodule formation. In view of the widespread use of LIPUS for the clinical therapy of periodontal disease, it is likely that LIPUS has an important influence on key functional activities of osteoblasts in alveolar bone.