Porphyromonas gingivalis has been implicated as an important etiological agent associated with periodontal disease, and emerging evidence suggests that immunotherapy against virulence factors of this pathogen may provide disease protection. Bacterial adherence to periodontal tissues is a prerequisite for colonization, and one of the important steps in the disease process, thus immunotherapy against adherence molecules is considered to be vital. Bacterial coaggregation and hemagglutination are factors that likely play major roles in colonization in the subgingival area. Since the public at large may be skeptical about the seriousness of periodontal disease, any immunotherapy employed must be carried out with absolute safety. To achieve this goal, the development of safe antibodies for use in passive immunization is significant. Herein, we discuss recent salient advances in immunotherapy against periodontal disease and introduce some biotechnological approaches for developing safe passive antibodies.

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The aims of this study were to investigate the status of systemic diseases and evaluate the relationship between systemic diseases and periodontal conditions in patients attending the Periodontal Clinic of Kagoshima University Hospital. A questionnaire was used to ask subjects about gender, age, height, weight, smoking, and systemic diseases. Clinical parameters, such as probing pocket depth and bleeding on probing recorded at the initial visit, were used in the data analysis. There were 970 subjects (male : 341, female : 629), and subjects in their fifties and sixties accounted for 60.9 percent of the total. Subjects with systemic diseases amounted to 76.6 percent. The most common systemic disease was abnormal blood pressure/vascular disease. The smoking group, abnormal blood pressure/vascular disease group, cerebrovascular disease group, and diabetic group had poorer clinical parameters at the initial visit than the no-systemic-disease group. Many of the patients attending the Periodontal Clinic are aged and have several systemic diseases. The severity of the patients' periodontal disease was associated with some systemic diseases. These observations suggest that knowledge of patients' general condition and cooperation with the medical doctors is required for safe and appropriate periodontal treatment.

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General Principles and Objects : According to the background of the crisis in periodontal infection, it is necessary to conceptualize the risk management concerning relationship between various risk factors and systemic damages in rural areas of the least developed countries. The Organization of International Support for Dental Education (OISDE), in cooperation with Japan International Cooperation Agency (JICA), has started to implement a primary health care program focused in the prevention of systemic damages caused by periodontal infection since 2003 to stretch over one year and six months. The program has been applied to 7 provinces and 25 districts with beneficiary residents of over 1,300 according to the methodology. In this study, the targeted area was focused two typical rural health centers in Stung Treng province. The project had been implemented three times in these health centers since January 2004 to March 2005 and the number of residents who checked our examination and primary health care were 194. Sixty residents who live in the downtown of Phnom Penh city were served as control group in quite advanced living environment conditions.
The purpose of this study is to investigate the influence of risk factors associated with poor living environment to the crisis in periodontal infection in rural area in the Kingdom of Cambodia as a field study.
Methods : Basic information of all visiting residents was charted according to our original concept. Living environment (LE) risk factors were charted based on a five-grade method. The contents of LE were as follows : 1) medical supply condition which means the distance from the referred hospital including private medical clinic, health center and health post, 2) sanitary (toilet) facility, 3) provision of safe water supply, and 4) situation of living in close proximity with the livestock. Medical systemic conditions of the residents were charted by interview method into history of systemic diseases and history of tropical infections. Also, general health conditions including physical examination of the heart and lungs sound, measurement of blood pressure, urine test and simply ECG (electrocardiogram) were assessed by the physician. The dental intelligence quotient (dental IQ) concerning periodontal infection was charted by question and answer method according to a five-grade classification. The periodontal infection was evaluated by dentists using a four-point method measurement of periodontal pocket depth, bleeding on probing (BOP), and mobility of each tooth. Plaque-induced gingival inflammation was examined by plaque control record (PCR method by O'Leary), which used a staining solution. At the same time, occlusal problems caused by missing tooth/teeth, decay, and orthodontic problem were confirmed.
Results : Statistical analysis by multiple regression analysis reveals that age ; plaque accumulation status, and living environment have very significant influences to the periodontal inflammatory status. The result demonstrates the situation of the living environment as a significant influence to the cause of periodontal inflammation.
Conclusion : The poor living and unsanitary environment may provide the vicious cycle of recurrent or prolonged infections leading to severe oxidative changes caused by the hyper functioning immune system. The end result of which is a hastened aging process. Therefore, a better living environment for the rural area residents is a must in order to prevent periodontal infections, as well as infectious tropical diseases.

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The aim of the present study was to evaluate the effect of different dentin surface conditionings followed by rhBMP-2 application to the dentin surface on the ALP activity of cultured cells that attached to the dentin surface in vitro, and on hard tissue formation on dentin surface and dentin resorption in vivo.
In the first experiment, 270 dentin blocks were divided into 3 groups, demineralized with EDTA (pH7.0), tetracycline-HCl (pH2.0), and citric acid (pH1.0), respectiveiy, for 3 minutes, and then soaked in 0, 5 or 10 μg/ml rhBMP-2 solution for 10 minutes. Periodontal ligament cells were seeded on each dentin block, and the ALP activity of the attachment cells was assessed on days 1, 3, and 5. In the second experiment, 144 dentin blocks were divided into 4 groups, exposed to EDTA, tetracycline-HCl, citric acid, and PBS, respectively, for 3 minutes, and then exposed to 0, 100, or 400 μg/ml rhBMP-2 solution for 10 minutes. The dentin blocks were later transplanted into the palatal connective tissue of rats, and specimens were prepared at 2 and 4 weeks after surgery.
The results of the first experiment showed that on day 3 and 5, the EDTA plus application of 10μg/ml rhBMP-2 group had higher ALP activity than the tetracycline-HCl group or citric acid group at any concentration of BMP-2. In the EDTA group, higher rhBMP-2 concentrations were associated with the greater ALP activity. The results of the second experiment demonstrated that the EDTA plus 100μg/ml rhBMP-2 group exhibited significantly higher cementum-like tissue formation any other group at any stage. At week 4, dentin resorption in the tetracycline-HCl plus 400μg/ml rhBMP-2 group was significantly promoted compared to all other groups. Dentin resorption in the EDTA group was not significantly different from the citric acid group. Higher rhBMP-2 concentrations induced higher dentin resorption in all demineralizations groups.
The results suggest that different dentin conditionings followed by rhBMP-2 application may have influenced the ALP activity of the attached cells in vitro, hard tissue formation on the dentin surface, and dentin resorption in vivo. EDTA demineralization, which induced formation of cementum-like tissue and suppressed dentin resorption, may be an appropriate method of dentin conditioning before rhBMP-2 application to the dentin surface for cementum-like tissue formation in vivo.

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It has been claimed that correlations exist between oral gas and periodontal disease. In this study the investigator measured oral gas with Motivation^® (SN-PD21703 : Sense It Smart Corporation, Tokyo) and assessed the status of periodontal disease by PSR (Periodontal Screening Recording). The aim of the study was to determine wether it is possible to prefigure periodontal disease on the basis of oral gas measurements. Motivation^® is a periodontal screening machine that measures odors, and it contains several semiconductor gas sensors. The investigators measured oral gas for three seconds in 94 patients and performed PSR as an indicator of periodontal disease status. They also tested oral gas and periodontal disease for correlations by using the artificial neural network constructed from the parameters of sensor characteristics and PSR codes. The results showed that the artificial neural network showed the advantaged prefiguration (r=0.97). PSR is an easy method to screen for periodontal disease. The results of this study, showed a high correlation between oral gas and periodontal disease, suggesting that measuring oral gas is easy and useful method for prefiguration of periodontal disease.

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We evaluated the effects of 24-year periodontal treatment in patients with intellectual disabilities. Subjects were 27 people —14men and 13 women with an average age of 33.1 years old at the first visit—who lived at a rehabilitation facility for those with intellectual disabilities. Periodontists lectured on the importance of oral hygiene, giving instruction in tooth brushing to 14 staff members. The staff them taught subjects in daily training. Clinical examination and measurement of the gingival index (GI), periodontal pocket rate (PoR), plaque control record (PCR), and number of missing teeth were evaluated at the baseline, the termination of initial treatment, and every months in regular checkups. A significant improvement was observed in GI, PoR, and PCR following initial preparation. During 22 years of maintenance, all three measurements—GI, PoR, and PCR—were lower than at baseline. The average number of missing teeth during maintenance was 0.96 per patient. These results suggest that the staff and patients recognized the importance of oral hygiene. The staff gave oral hygiene training regularly. This together, with a checkup every 6 months, effectively maintained the oral health of patients. During maintenance, however, PCR increased slightly, mainly due to decreasing recognition of the importance of oral hygiene caused by an aging patient population and staff turnover. This indicates that more frequent checkups, i.e., every 1-3months and annual staff training are needed to maintain the oral health of patients.

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Tissue inhibitor of metalloproteinases-1 (TIMP-1) and TIMP-2, originally known as intrinsic inhibitors of matrix metalloproteinases (MMPs), are now known as constitutive components in serum and have potent cell growth-promoting activity. In this study, we examined the effects of TIMPs in FCS on osteoclast-like (OCL) cell formation in mouse bone marrow culture. The OCL cell formation is totally dependent on the presence of PGE₂ or 1α25 (OH)₂D₃ or IL-1α. The effects of these factors were, however, not completely but greatly suppressed by deleting TIMP-1 and TIMP-2 from FCS in culture. But the suppression was almost fully recovered by the readdition of the same amount of recombinant (r) TIMPs which were detected in 10% FCS. As low molecular weight MMP inhibitors could not substitute rTIMPs for the recovery, TIMP activity on the OCL cell formation seemed to be independent from their MMP inhibitory activity. These results strongly suggest a secondary but potent stimulating activity of TIMPs on OCL cell formation. In conclusion, TIMPs in serum play an important role in osteoclastgenesis in mouse bone marrow culture.

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Today, guided tissue regeneration (GTR) and enamel matrix derivatives (EMD) are accepted widely as the regenerative periodontal therapy. Regenerative periodontal therapy by GTR is to create the regenerative space using a physical barrier membrane. On the other hand, regenerative periodontal therapy by EMD is the application of enamel matrix proteins to root surface. So, we report a case of simultaneous approach by GTR and EMD to the continuous bone defects. Such a clinical case has not yet been reported.
A 55-year-old woman was treated by GTR and EMD simultaneously between the maxillary right canine and the second premolar interdental bone defects. The membrane was removed after 4 weeks. The clinical observation showed that GTR and EMD were almost equal in the amount, however, the surface characteristic of regenerated tissue by EMD was redder and softer than GTR. The radiographic observation showed that radio-opacity was increased at 6 months in GTR and at 9 months in EMD.
This case presentaion indicated that regenerative tissues by GTR and EMD could be confirmed at the time of membrane retrieval. This clinical findings suggest that the surface characteristics of regenerated tissues by GTR and EMD was different. Therefore, it is necessary to do further studies on the biochemical analysis of the periodontal healing process by GTR and EMD.

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