Our retrospective survey was to determine the prevalence of tooth loss and associated dental pathologies during active and maintenance periodontal therapy by the general practitioner. Results were compared to those from the periodontal clinic at the Nippon Dental University School of Dentistry at Niigata. Subjects were 92 patients diagnosed with chronic adult periodontitis who had undergone comprehensive care consisting of periodontal and restorative treatment and who had participated in a supervised maintenance program for over 5 years. 38 patients were at the periodontal clinic.
Results indicated that 3.3% of periodontally treated teeth were lost during active treatment or maintenance among patients seen by general practitioners and 6.2% at the periodontal clinic.
The only pathology of periodontal disease was observed in 61% of patients seen by general practitioners compared to 89.7% at the periodontal clinic. The pathology of periodontal disease was observed in about 90% of periodontal clinic patients. Caries and endodontic pathology were observed in about 40% of patients seen by general practitioner. Some 32.5% of the only pathology for periodontal disease were lost at general practitioners during active treatment compared to 77.6% lost at the periodontal clinic. Some 28.6% of teeth treated by general practitioners were lost during the maintenance phase compared to 12.1% at the periodontal clinic. Almost all teeth were lost during active treatment at the periodontal clinic. The rate of teeth loss during maintenance due to periodontitis was 1.0% for general practitioners' patients and 0.8% at the periodontal clinic. This suggests that treatment was effective for long-term maintenance of dentition in these subjects.

View full abstract

We compared the range and percentage of paint removed by air scaler, in subgingival scaling and root planing with curettes using a teaching model.
The roots of removable teeth were uniformly coated with a paint layer and the model attached to a mannequin. Mechanical instrumentation was performed using the SONICflex^® LUX 2000 L (Kavo EWL, Germany) air scaler with a SONICflex^® paro tip compared to Gracy curettes (Mini-five^®, Hu-Friedy, U.S.A.). Teeth examined were lower left, right central, and lateral incisors, upper left first premolar, and lower left second molar. Subjects were 20 operators equally divided into an amateur group (<1 year of periodontal practice) and a professional group (≥8 years of periodontal practice). Instrumented areas were analyzed to assess the range and percentage of paint removed by a computerized image analysis and compared for 2 types of instrumentation and 2 operator's groups.
In the amateur group, the range reached by the air scaler was deeper than that of the curette for almost all aspects of examined teeth and among professionals, deeper for all aspects. The lingual aspect of the upper left first premolar and the distal aspect of the lower left second molarwas significant (p<0.01).
The percentage of paint removed by curettes was the same and/or greater than that by the air scaler in both groups on lower incisors and the upper left premolar. However, on the lower left second molar, the percentage of paint removed by the air scaler was greater than that by curettes. The distal aspect in the professional group was significant (p<0.01).
The range in the professional group was deeper than that in the amateur group for almost all aspects of teeth.
The percentage of paint removed in the professional group was greater than that in the amateur group for all aspects.
The range reached by air scalers was deeper than that by curettes. For aspects with deep intrabody defects, both the range and percentage of paint removed by air scalers were superior to those by curettes. Air scaler technique was appeared difficult for the amateur group, suggesting the need for greater practice to achieve instrumentation effectiveness.

View full abstract

Previous reports suggested that the association between serum IgG subclass levels and periodontal status is influenced by genetic and environmental factors, such as race and smoking. Japanese population living in the same area may be appropriate for evaluating this association due to similar racial and environmental factors. The present cross-sectional investigation studied this association in an elderly population of 451 subjects aged, 71 years residing in Niigata, Japan. Smokers and edentulous individuals were excluded. Dentulous nonsmokers were classified into 2 groups based on the number of teeth : those with fewen than 20 teeth and those with 20 or more teeth. The percentage of sites with PAL≥4mm and serum IgG 1 levels was significantly higher in subjects with fewer than 20 teeth. A significant negative correlation was observed between the number of teeth and IgG 1 subclass levels. This data indicates that higher levels of serum IgG 1 are associated with reduced numbers of teeth in a Japanese elderly population. Longitudinal investigation is necessary to clarify the reason for this in periodontitis-susceptible individuals.

View full abstract

Platelet releasate (PR) has been used in regenerative medicine because it contains cell growth factors such as transforming growth factor-β (TGF-β) and platelet-derived growth factor (PDGF) that are effective in regenerating periodontal tissue. There have been many clinical reports on the use of PR, which is prepared by concentrating and processing human platelets, but the biological effects of PR on cells have not been fully clarified. Hence, to ascertain the effects of PR on periodontal tissue-derived cultured cells, TGF-β1 expression was measured using RT-PCR and ELISA and cell proliferation activity was assessed by monolayer and three-dimensional (3-D) culture methods. The results showed that the cell proliferation activities of periodontal tissue-derived human gingival fibroblasts (HGF), vascular endothelial cells (HVEC), epithelial cells (HEC), and periodontal ligament fibroblasts (HPLF) were greater with PR compared to cells cultured without PR. Next, the effects of PR on the cell proliferation activity of HGF and HPLF were investigated by the 3-D culture method using collagen matrix. The results showed that when compared to the no addition of PR, there were increases in cell proliferation rates on addition of PR (HGF : 2.66 times, HPLF : 4.37 times). Furthermore, when PR was added to PR-treated HPLF, the expression of TGF-β1 mRNA (3.38 times) and the production of TGF-β1 (24, 48, 72h PR FCM : 10.76, 12.15, 13.02ng/ml) by these cells increased.
The above findings show that PR facilitates the growth of cells that make up damaged periodontal tissue, and when scaffolding (collagen matrix) is provided, even more stable cellular proliferation is achieved. Also, since PR increases the production of TGF-β1, a growth factor important for periodontal regeneration, to levels sufficient to meet the conditions necessary for tissue regeneration, PR appears to be useful for regenerating periodontal tissue in vitro.

View full abstract

The efficacy of professional tooth cleaning instruction (PTCI) in adolescents to arrest periodontal disease was assessed. Women high school students in Sendai were examined for periodontal conditions using Community Periodontal Index (CPI, WHO) from 2000 to 2003. The total score was represented as the sum of CPI scores for 6 index teeth in each subject. The largest score was represented as the maximum score for 6 index teeth in each subject. We selected 39 subjects having total CPI score (10-14) in 2001 and 26 in 2002 having 10-14 of total CPI score for this prophylactic program. The probing pocket depth of each index tooth was measured in each student. Next, O'Leary Plaque Control Record (O'Leary's PCR) was recorded after 5 min brushing by themselves. Then, subjects had an additional 10 min of brushing by themselves. Finally, brushing was instructed using a conventional brush, Dent EX slim head #33 and one-tuft M (Lion Corp., Tokyo). This PTCI was condncted at 1-week intervals for 10 weeks.
O'Leary's PCR in all subjects decreased significantly from the initial examination to the final one in 2001 (p<0.01) and in 2002 (p<0.001). These changes indicated that subjects acquired techniques to remove the cervical and proximal plaque. Both total and maximum CPI decreased significantly (p<0.05, p<0.001) at the examination after PTCI. The mean probing pocket depth of index teeth decreased slightly at the last PTCI, but no significant differences were seen between the first CPI examination and the last PTCI. Maximum pocket depth decreased significantly at the last examinations in 2001 (p<0.05) and 2002 (p<0.001).
Despite approximately 3% of all students who only received PTCI, smaller total CPI scores increased in all students (p<0.001), so this PTCI for a small group may have spread to the wider group.
Brushing technique was improved by sufficient, repeated PTCI for adolescents and the progression of incipient periodontitis was arrested and improved their periodontal conditions. Consequently, this program may contribute to the prophylaxis of periodontal disease in adolescents.

View full abstract