This study examined the efficacy of YM175 [disodium dihydrogen (cycloheptylamino) methylene-1, 1-bisphosphonate] in reducing alveolar bone loss caused by experimental periodontitis in beagle dogs. Thirty-six dogs were used and divided into 6 groups. Periodontitis was induced in 30 dogs (groups 2-6) by ligating the bilateral mandibular third and fourth premolar teeth with silk ligatures and by feeding a soft diet. Six dogs were sham-operated (group 1). Saline (placebo), flurbiprofen (0.02 mg/kg) and YM175 (0.01, 0.1 and 1.0 mg/kg) were administered to the dogs (groups 2-6) 5 d/wk for 25 wk. Radiographic and morphometric analyses were performed. In placebo-treated animals (group 2), the ligation caused a significant decrease in the alveolar bone height by 0.57 and 1.91 mm at 2 and 25 wk, respectively. YM175 (1.0 mg/kg) prevented the decrease in bone height by 47 and 31% at 2 and 25 wk. YM175 (0.1 mg/kg) and flurbiprofen tended to prevent bone loss after 15 wk. Although the ligation elicited no significant change in bone mineral density, it significantly decreased bone volume. YM175 (1.0 mg/kg) and flurbiprofen tended to increase the bone volume. The number of formative or resorptive Haversian canals and the bone turnover through the periosteal bone surface were increased by the ligation, indicating the increased turnover of the cortical bone. YM175 (1.0 mg/kg) reduced the increased bone turnover. The gingival index was maximally increased at 2 wk and was suppressed by YM175. These results suggest that YM175 prevents alveolar bone loss by reducing the increased alveolar bone turnover in dogs with periodontitis.

Samples of subgingival bacteria were collected from two sites of anteriors with• †6mm deep pockets in each ten patients in a clinically characterized rapidly progressive periodontal disease.

No abstract

Seven juvenile periodontally diseased patients were evaluated for clinical, microbiologic and local or systemic host factors. Three patients showed the localized from of periodontitis clinically and radiographically and by deep periodontal pockets associated with the molars and incisors. Four were in the generalized froms, in which in most cases all teeth were affected.

The purpose of this study was to determine the effect of chlorhexidine digluconate mouthrinses on the development of dental plaque in man. The dental plaques were formed on strips of triacetylcellulose film (TAC), which were attached to the lingual surfaces of the mandibular incisors by silk suture thread on 20 human volunteers. Differences in the degree of plaque formation on TAC films after 2, 4 and 24 hours were observed in placebo vs. chlorhexidine treated samples using both scanning and transmission electron microscopy. It was found that (1) solutions containing chlorhexidine digluconate and lactic aluminum have an inhibitory effect of the development of dental plaque on the TAC film as evaluated by electron microscopy, (2) the TAC film was a convenient model for the study of early dental plaque formation by electron microscopy, (3) the three types of pellicle reported by Tryggve Lie (1977) were also observed, (4) the method enabled evaluation of the bacterial accumulation of TAC films. After 2 hours, there was no visible difference in the bacterial accumulations on placebo or chlorhexidine treated films. After 4 and 24 hours considerable differences were observed.