[Association between chronic periodontitis and metabolic syndrome related mitochondria single nucleotide polymorphism].

OBJECTIVE: To investigate the relationship between Mitochondrial DNA(mtDNA) SNP and the severity of periodontitis. METHODS: In the study, 227 subjects in a community of Beijing received questionnaire interview, periodontal examination and biochemical laboratory examination in 2005. The designed primer was used to amplify the specific mtDNA fragments with PCR, and sequence the PCR products. Finally, the relationship between severity of chronic periodontitis and mtDNA SNP at site 10398 was analyzed. RESULTS: The number of the subjects included at mtDNA site 10398 was 227. The G allele frequency in the metabolic syndrome(MS) subjects was significantly higher than that in the non MS subjects [80(70.2%) vs. 34(29.8%),P=0.039 ]. The result of Logistic regression showed that the subjects with G allele had higher risk of MS than the subjects with A allele(OR=1.77,95%CI=1.02-3.06, P=0.042). But there was no significant relationship between the 10398 A→G SNP and severity of periodontitis. CONCLUSION: In this population, mtDNA SNP 10398 A→G may be associated with MS. However, there was no relationship between the 10398 A→G SNP and severity of chronic periodontitis.

[Effects of dental health awareness and behaviours on the glycemic metabolic characteristics and periodontal disease of patients with type 2 diabetic].

OBJECTIVE: To analyze the effects of dental health awareness and behaviours on the relationship between glycemic metabolic characteristics and periodontal disease of type 2 diabetic patients. METHODS: In the study, 83 subjects with type 2 diabetes mellitus were recruited. The clinical periodontal indexes, such as pocket probing depth (PPD), attachment loss (AL), modified bleeding index (mBI), plaque index (PLI) were obtained with a Williams type periodontal probe; Laboratory examinations including glycosylated haemoglobin A1(HbA1C) were made, glucose assay tested, and the structured questionnaire interview conducted evaluationg the knowledge, attitude and practice (KAP) about periodontal health. RESULTS: The prevalence of moderate and severe periodontitis was 67.5%, compared with mild periodontitis, whose severities were affected by the higher level of HbA1C (≥8.0%) (OR 54.1-143.1), followed by using glycemic drug (OR=12.9-44.6), stress (OR=16.9-29.6), and the dissatisfaction with diabetic therapy (OR=16.9-18.0) et al. Meanwhile the attachment loss conditions were also correlated with the poor periodontal knowledge level(OR=3.4),older age(OR=1.1),and misjudgement of gingival inflammation (OR=13.3) et al. On the other hand, individuals with moderate and severe periodontitis, having bad teeth brushing effects and knowing about dental plaque inadequately, had a significantly higher risk for the poorly controlled glycemic results (HbA1C≥8.0%), and the OR was 8.61, 8.07, and 7.49 respectively. CONCLUSION: In patients with type 2 diabetes the severity of periodontal disease and the glycemic metabolic level (HbA1C) have a definite bidirectional adverse interrelationship, which is affected by the dental health awareness and behaviours.

[Detection of periodontal pathogens from saliva of type 2 diabetic patients in urban area of Beijing].

OBJECTIVE: To investigate the prevalence of periodontal pathogens from saliva of patients with type 2 diabetes mellitus (T2DM), and to characterize the association between the glucose status and periodontal pathogens in oral cavity. METHODS: All the subjects were hypertension patients under regular care at Beijing hypertension prevention and management institute. Whole unstimulated saliva samples were collected from 45 non-diabetic subjects (non-DM group), 80 well-controlled diabetic patients (DM-well group) and 100 poor-controlled diabetic patients (DM-poor group). DNA was extracted from the salivary deposition, Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf) and Treponema denticola (Td) were detected by polymerase chain reaction (PCR) method based on 16SrRNA. Prevalence and quantity of the pathogens under different glucose states were compared and logistic regression model was set to analyze the factors related to each bacterium. RESULTS: The prevalence of Tf in DM-well group and DM-poor group was significantly lower than that of non-DM group [81% (65/80), 80% (80/100) vs 91% (41/45), P = 0.048], meanwhile the quantity of Tf was also lower than that of non-DM group [1.9(2.6), 2.1(5.3) vs 3.4(6.4)] (P > 0.05). With the worsening of glucose control, the quantity of Tf was declining (P = 0.032). However, the prevalence and the quantity of Pg, Td in 3 groups had no statistical differences (P > 0.05). After adjusting age, gender, number of missing teeth and other periodontal parameters, OR of having Tf in saliva from DM-well group and DM-poor group was 0.58 and 0.53, respectively. CONCLUSIONS: Abnormal blood glucose state may affect the colonization of Tf in oral cavity.

[Periodontal status of patients with post-acute myocardial infarction].

OBJECTIVE: To evaluate the periodontal status of post-acute myocardial infarction patients, to identify whether periodontitis is associated with post-acute myocardial infarction in Chinese community population. METHODS: Case and control subjects were enrolled from a community population, the diagnose of post-acute myocardial infarction and systemic health were based on blood, electrocardiogram and ultrasound examinations by physicians. Full mouth periodontal examinations were performed in 103 post-acute myocardial infarction patients and 52 healthy subjects. Mesial-buccal and distal-lingual sites per tooth were examined. The periodontal parameters including plaque index (PLI), bleeding index (BI), probing depth (PD), attachment level (AL) and missing teeth number were recorded. Information of demographic data, behavior habits and general conditions were obtained by a questionnaire. Periodontal status were compared between case and control groups, the association between AL, PD, PLI, missing teeth and post-acute myocardial infarction was analyzed by Logistic regression. RESULTS: In post-acute myocardial infarction group, there were 83 males, 20 females, mean age was 68(41 to 84)years old, in healthy subjects there were 30 males and 22 females,mean age was 62(42 to 78) years old. There were no statistically differences between two groups in age structure, smoking condition, education status and working condition, but body mass index, total cholesterol, triglycerides and glucose in post-acute myocardial infarction group were significantly higher than that in healthy group,while high-density lipoprotein significant lower . The number of missing teeth(6.89±7.39 vs. 4.21±5.62, P=0.01), mean AL [(3.48±2.34) mm vs. (2.61±1.85) mm, P=0.02] and prevalence of severe periodontitis (44.7% vs. 32.7%, P<0.01) were significantly higher in post-acute myocardial infarction patients than that in healthy subjects. Plaque index (1.69±0.49 vs. 1.57±0.50, P=0.22), PD (2.88±1.02 vs. 2.64±0.68, P=0.09) were higher in post-acute myocardial infarction patients than that in healthy subjects, but not statistically significant. In the multivariate analysis, after adjusting sex, age, smoking, body mass index, diabetes, hypertension and serum lipid, AL≥4.00 mm was a significant risk indicator for post-acute myocardial infarction(odd ratio 4.89, 95%confidence interval 1.26 to 18.94, P=0.02). CONCLUSION: Periodontal status was worse in post-acute myocardial infarction patients than that in healthy subjects, AL≥4.00 mm was an independent risk indicator for post-acute myocardial infarction.

[Correlation between periodontitis and metabolic syndrome of the middle-aged and aged population in Shijingshan community of Beijing].

OBJECTIVE: To survey the metabolic status of the middle-aged and aged population with periodontitis in Shijingshan community of Beijing, and investigate the relationship between periodontitis and metabolic syndrome (MS). METHODS: The middle-aged and aged population in the community were investigated by questionnaires, periodontal clinical examinations and blood biochemical tests in 2005. A total of 903 subjects were enrolled, who were divided into two groups by severity of periodontitis. Their waist circumferences, values of high-density lipoprotein cholesterol (HDL-C), systolic blood pressure, fasting glucose, MS and its individual components (central obesity, insulin resistance, hypertriglyceridemia, low HDL-C and hypertension) were compared between the two groups. The Logistic regression model was set to analyze the relationship between periodontitis and MS. RESULTS: There was a significantly higher mean of systolic blood pressure, fasting glucose in the subjects with moderate-severe periodontitis than that with no-mild periodontitis. With severity of periodontitis increasing, the prevalence of MS, high blood glucose and low HDL-C increased significantly. After adjustment for gender, age, and smoking, the subjects with moderate-severe periodontitis were 1.524, 1.527 and 2.349 times more likely to suffer from MS, high blood glucose and low HDL-C than those with no-mild periodontitis, respectively. CONCLUSION: With severity of periodontitis increasing, the prevalence of MS, high blood glucose and low HDL-C increased significantly in the middle-aged and aged population of the community in Beijing. Severity of periodontitis is associated with MS, high blood glucose and low HDL-C.

[Granulocyte elastase levels in saliva and gingival crevicular fluid of subjects with various periodontal conditions].

OBJECTIVE: To compare the granulocyte elastase (EA) levels in saliva and/or gingival crevicular fluid (GCF) of subjects with various periodontal conditions and analyze the relation between EA levels in GCF and in saliva. METHODS: GCF and salivary samples were collected from 17 subjects with healthy periodontium, 14 with gingivitis, 24 with chronic periodontitis (CP) and 24 with aggressive periodontitis (AgP). The EA levels in GCF and saliva were analyzed. RESULTS: The GCF-EA level in AgP were significantly higher than that in CP (0.485 3 ± 0.225 0 vs. 0.288 4 ± 0.193 1, P<0.01); the levels of EA in saliva of periodontitis patients (AgP and CP) were higher than those of healthy and gingivitis subjects (0.844 5 ± 0.660 6, 0.637 3 ± 0.648 9 vs. 0.031 6 ± 0.020 6, 0.012 2 ± 0.005 8, P<0.001). A positive correlation was found between EA levels in saliva and those in GCF (r=0.660). CONCLUSION: GCF-EA level may serve as a marker for clinical assessment of periodontal conditions. The measurement of EA levels in saliva may facilitate to overall screen periodontitis patients in epidemiological study or to monitor periodontal conditions in clinical practice.

[Relationship between the preterm low birth weight infant and the periodontal pathogen bacteria in maternal saliva].

OBJECTIVE: To investigate the possible relationship between the preterm and/or low birth weight (PLBW) and three anaerobic microorganisms in saliva of their mothers, including Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema Denticola (Td). METHODS: 110 retrospective cases were collected from 4 hospitals in Beijing urban and suburban areas. PLBW group included 72 subjects and NBW group included 38 subjects. They were made up of 2:1 matched data. Nonstimulated saliva samples were collected from all the individuals. The periodontal examinations included plaque index (PLI), probing depth (PD), bleeding index (BI), and clinical attachment loss (CAL) were performed in 1-1.5 years after preterm. According to the PCR results in their saliva, they were divided into positive group and negative group of Pg, Tf, Td. RESULTS: CAL in PLBW and NBW groups were 0.18 (0.00, 4.97) mm and 0.08 (0.00, 1.81) mm respectively which was significantly different (P<0.05). The detection rates of Pg in PLBW and NBW groups were 94.4% and 78.9% respectively (P<0.05). The detection rates of Tf were 84.7% and 94.7% respectively (P>0.05). The detection rates of Td were 86.1% and 89.5% respectively (P>0.05). The clinical parameters of CAL [2.25(0.54, 4.00) mm, 1.44(0.63, 3.80) mm], PD[(2.47 ± 0.43) mm, (1.94 ± 0.39) mm], PLI (1.80 ± 0.44, 1.36 ± 0.34) in Pg positive group was significantly higher than those in Pg negative group. The birth weight of Pg positive group [(2 482.95 ± 813.17) g] was significantly lower than Pg negative group [(3 425.00 ± 1 024.36) g]. CAL [0.14(0.00,4.9) mm, 0.03(0.00,0.44) mm], PD[(2.44 ± 0.46) mm, (2.17 ± 0.38) mm] were significantly different between Tf positive and negative group. PD [(2.44 ± 0.46) mm, (2.14 ± 0.43) mm] and BI (2.31 ± 0.86, 1.83 ± 0.68) were significantly different between Td positive and negative group. CONCLUSION: There is higher level of Pg, Tf and Td in the saliva of both PLBW and NBW groups. The detection of Pg may be related to PLBW.

[Effect of community periodontal care intervention on periodontal health and glycemic control in type 2 diabetic patients with chronic periodontitis].

OBJECTIVE: To evaluate the effectiveness of community periodontal care intervention in type 2 diabetic patients with chronic periodontitis who participated in community non-communicable diseases management service. METHODS: The randomized controlled and blinded community trial with a duration of six months was designed to compare effects of "periodontal initial therapy" on group I(22 cases), of "professional mechanical tooth cleaning (PMTC), i.e. coronal scaling" on group II(19 cases)and of "non-clinical therapy" on the control group(25 cases). The clinical periodontal indexes, such as probing depth (PD), attachment loss (AL), modified bleeding index (mBI), plaque index (PLI) were obtained with a Williams type periodontal probe; Laboratory examinations including glycosylated haemoglobin A1(HbA1C), glucose assay, were conducted. RESULTS: The reductions of PD in groups I and II were 0.71 and 0.70 mm, respectively, which was more significant than in control group (0.20 mm); the reductions of AL in groups I, II, and control group were 0.86, 0.57, and 0.03 mm, respectively, which showed significance in all the three groups. The subjects of groups I and II had 0.56% and 1.01% reductions of HbA1C respectively, and the significance was observed in group II. In addition, the improvement of HbA1C values in group II was highly correlated with the decrease in gingivitis (r=0.51, P=0.03). CONCLUSION: The community periodontal care approaches implemented in the community health service centers have significantly improved periodontal health as well as reduced glycemic level, which could be regarded as basic health care strategies for the patients with diabetes.

[Association between preterm low birth weight and maternal cytokine levels of saliva and gingival crevicular fluid].

OBJECTIVE: To examine the hypothesis that periodontitis was one of the sources of inflammation in preterm low birth weight (PLBW) mothers and investigate the relationship between PLBW and inflammatory factors. METHODS: The samples of saliva and gingival crevicular fluid (GCF) were collected from 83 PLBW mothers (PLBW group) and 44 normal birth weight (NBW) mothers (NBW group). The levels of IL-1beta and IL-6 were analyzed by enzyme-linked immunosorbent assay. The concentrations of cytokines in saliva and GCF were compared between the two groups. RESULTS: IL-1beta level in saliva of PLBW group was higher than which of NBW group significantly [(78.32+/-11.81) ng/L vs. (39.66+/-11.89) ng/L, P<0.05]. There was no statistically significant difference on IL-6 level in saliva [(17.45+/-3.13) ng/L vs. (16.28+/-0.66) ng/L], IL-1beta level in GCF [(93.58+/-13.22) ng/L vs. (81.38+/-9.28) ng/L] and IL-6 level in GCF [(15.35+/-0.28) ng/L vs. (14.87+/-0.37) ng/L) between two groups, but those of PLBW group were higher than NBW group. Significant negative correlations existed between gestational age at delivery and probing depth. It was also found significant negative correlations between gestational age at delivery and IL-6 (r=-0.274, P<0.01), between the weight of the new born infants and IL-6 levels in saliva (r=-0.424, P<0.01), IL-1beta level in GCF (r=-0.231, P<0.01). CONCLUSIONS: There was a tendency presenting the higher inflammatory cytokine in GCF and saliva, the shorter gestation period and the lower birth weight. The levels of cytokine in saliva and GCF were higher in PLBW mothers. The correlation may be exist between maternal periodontitis and PLBW.

[Levels of tumor necrosis factor-alpha and interleukin-1beta in saliva of metabolic syndrome patients].

OBJECTIVE: To investigate the association between periodontitis and the low-grade inflammation in metabolic syndrome (MS) patients. METHODS: Fifty-seven MS patients, 26 healthy controls were enrolled. Non-stimulated whole saliva was collected. The levels of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta was analyzed by radioimmunoassay and enzyme-linked immunosorbent assay, respectively. Concentration of cytokines was compared between MS patients and the healthy controls. Correlations between the cytokines and various periodontal indices, and between the cytokines level and different quantity of metabolic syndrome components were also investigated. RESULTS: Levels of TNF-alpha in saliva of MS patients [(69.30+/-21.01) ng/L] were significantly higher than that in the healthy subjects [(57.85+/-15.69) ng/L, P<0.05], and of IL-1beta in MS patients [(616.42+/-360.05) ng/L] higher than that in healthy subjects [(506.06+/-245.76) ng/L], but the difference was not statistically significant. TNF-alpha was positively correlated with bleeding index (BI). In MS patients, TNF-alpha level and IL-1beta level increased with increasing severity of periodontal disease and increasing component numbers of MS. CONCLUSIONS: Periodontal inflammation may be one of the sources of low-grade inflammation in MS patients. Both systemic and periodontal conditions may influence the level of salivary TNF-alpha and IL-1beta.

[Combination therapy of periodontal intrabony defects with demineralized freeze-dried bone powder and platelet-rich plasma].

OBJECTIVE: To evaluate the effect of decalcified freeze-dried bone allograft (DFDBA) and DFDBA with platelet-rich plasma (PRP) in the treatment of periodontal infrabony defects. METHODS: Fifteen periodontal infrabony defects (30 sites) in 12 patients with periodontitis (9 patients with chronic periodontitis and 3 patients with aggressive periodontitis) were selected. Three months after initial therapy, they were assigned to either the DFDBA group (10 defects with 20 sites) or the DFDBA with PRP group (5 defects with 10 sites). The patients were evaluated for plaque index (PI), bleeding index (BI), probing depths (PD) and clinical attachment loss (CAL) before the treatment and at 6 months after periodontal bone graft surgery. RESULTS: The PI, BI, PD and CAL in the DFDBA group were 1.7, 2.7, 6.0 mm and 7.0 mm at baseline; 1.5, 1.8, 3.9 mm and 4.4 mm at the 6 months after periodontal surgery. The PD, CAL and BI in DFDBA with PRP group at baseline were 6.2 mm, 7.1 mm and 2.9; 3.2 mm, 3.6 mm and 1.7 at the 6 months after periodontal surgery. The PI did not change significantly after surgery in both groups. While both groups showed significant improvement (P<0.01) in BI, PD and CAL, the improvement in the DFDBA with PRP group was significant greater than in the DFDBA group (P<0.05). CONCLUSION: DFDBA is an effective therapy for periodontal intrabony defects. DFDBA with PRP can significantly improve the clinical effect of periodontal infrabony defects.

Relationship of metabolic syndrome to chronic periodontitis.

BACKGROUND: Many studies have suggested that periodontal disease is related to metabolic disorders. Few studies have investigated metabolic syndrome (MS), as defined by the International Diabetes Federation in 2005, in the Chinese population. The aim of this study was to assess the association of periodontitis with MS. METHODS: In this case-control study, 152 patients with MS and 56 generally healthy adults received a comprehensive clinical dental examination. Attachment loss, probing depth, bleeding index, and plaque index were examined at two sites per tooth (mesio-buccal and disto-lingual). The number of missing teeth was noted in each subject. RESULTS: The male patients with MS were significantly younger and their periodontal parameters were significantly higher than those of the healthy group. The female patients with MS were significantly older, and all periodontal parameters were higher than those in the healthy group; only plaque index was statistically significantly different (P = 0.001). After adjustment for gender, age, and smoking, the corresponding adjusted odds ratios for MS were 6.9 (95% confidence interval [CI]: 1.07 to 44.77), 9.9 (95% CI: 1.50 to 65.24), and 15.6 (95% CI: 2.20 to 110.43) for subjects with attachment loss > or = 3 mm in >0% to 33% of sites, >33% to 67% of sites, and >67% of sites, respectively. Most periodontal parameters were highest in patients with four components of MS, but these differences were not statistically significant. CONCLUSION: Patients with MS had poor periodontal conditions, and periodontal disease was associated with MS, independent of other risk factors.

[Association between periodontitis and preterm low birth weight].

There were increasing studies on the association of periodontitis with preterm low birth weight (PLBW) in the recent 10 years. PLBW is associated with about half of all perinatal mortality. Known factors which could induce PLBW include smoking, genetics, alcohol, prenatal care, nutrition, urinary tract infections, However, there are still about 25% of PLBW cases occur with etiology unknown. Many evidences supported the association between periodontitis and PLBW. Periodontitis is a risk factor of PLBW, but the mechanism is unclear. Current theory suggests that periodontal inflammation adversely affects pregnancy outcomes by one or two mechanisms. First, women with periodontal disease may experience more frequent and severe bacteremia than periodontally healthy women. As a result, the uterine cavity may become exposed to or colonized by periodontal bacteria or their byproducts (e.g. lipopolysaccharides). Once they reach the maternal-fetal unit, oral bacteria may elicit an inflammatory cascade that leads to preterm labor. A second putative mechanism does not require oral bacteria to colonize the uterine cavity. Rather, cytokines generated within the diseased periodontal tissue may enter the systemic circulation and precipitate a similar cascade, again leading to spontaneous preterm labor and birth. Therefore, oral health instruction and periodontal treatment may decrease the infection of periodontal pathogens and reduce the risk of PLBW. For the present, the best advice for a woman who contemplate pregnancy is effective brushing for two times per day and regular periodontal treatment.

[Association between mother's periodontal status and preterm low birth weight in Beijing].

OBJECTIVE: To investigate the possible association between mother's periodontal status and preterm low birth weight (PLBW) in Beijing. METHODS: The periodontal status of 83 women who bore a preterm low birth weight infant (PLBW group) and 44 women who bore a normal birth weight infant (NBW group) within two years in four hospitals in Beijing were evaluated. These women were all generally healthy. The clinical periodontal parameters including plaque index (PLI), probing depth (PD), attachment loss (AL) and bleeding index (BI) recorded. RESULTS: The percentages of PD > or = 4 mm sites, AL > or = 2 mm sites and BOP(+) sites in two groups were 8.1% vs 6.9%, 12.8% vs 6.1% and 70.4% vs 66.9%, respectively, which showed significantly higher in PLBW group than in NBW group(P < 0.01, P < 0.001, P < 0.01). CONCLUSIONS: There was possible association between mother's periodontal status and preterm low birth weight in the investigated area. Poor periodontal status may be one of the risk factors of PLBW.

[Affecting factors for height of adjacent gingival papilla of maxillary central incisor single implant].

OBJECTIVE: To analyze and find factors affecting the height of adjacent gingival papilla of maxillary central incisor single implant in human in order to promote the esthetic result of dental implants. METHODS: Sixteen maxillary central incisor single implants of 16 patients and 30 sites of adjacent tissues and prosthesis were evaluated. Data on the height of adjacent gingival papilla of dental implant and relative factors were obtained from clinical parameters, photographs, research models, and X radiographs. RESULTS: The mean and standard deviation of adjacent gingival papilla height of maxillary central incisor single implant were (4.01 +/- 1.85) mm. Statistical analysis revealed that factors affecting the height of adjacent gingival papilla of implant were as following from strong to weak: vertical distance between contact point and gingival margin, vertical distance between proximal bone level of natural tooth and implant abutment, vertical distance between proximal bone level of natural tooth and contact point, proximal protruding degree of crown, horizontal distance between abutment and root, length ratio of the crown and fixture, vertical distance between proximal bone level of implant and abutment, lip-side protruding degree of crown, probing depth. CONCLUSIONS: Multiple factors affected the height of adjacent gingival papilla of maxillary central incisor single implant in human.

[Prevalence and related factors of periodontitis in community-dwelling Chinese with diabetes].

OBJECTIVE: To evaluate the periodontal conditions in community-dwelling Chinese with diabetes and analyze some related factors. METHODS: A total of 90 (45- to 84- year-old) patients with diabetes, participating in community-based non-communicable diseases management system, were recruited in this study. The examination items on these patients included periodontal measurements performed by pocket probing depth (PPD), attachment loss (AL), sulcus bleeding index (SBI), plaque index (PLI), and blood sugar metabolic level surveillance, as well as structured questionnaire interview. RESULTS: The prevalence of periodontitis was 100%, while 37.1% was diagnosed as having mild periodontitis, 24.4% with moderate, and 38.5% with advanced periodontitis. The AL level in male was significantly higher than that in female. The periodontal destruction was highly correlated with HbA1C value and affected by some socio-behavior factors based on multinomial logistic model. CONCLUSIONS: There is a positive correlation between AL and HbA1C level, and AL and HbA1C should be measured regularly. The patients' periodontal inflammation needs effective control. Priority should be given to the low income population and those with little periodontal knowledge for behavior interventions.

[Correlation between sulfide levels in periodontal pocket of periodontitis patients and periodontal clinical parameters].

OBJECTIVE: To assess the correlation between sulfide levels in periodontal and volatile sulfide compounds (VSC) in oral cavity and to assess the correlation between sulfide levels in periodontal pocket (pS) and periodontal clinical parameters. METHODS: VSC in oral cavity was measured by halimeter one week after grossly supragingival cleaning. Then pS in periodontal pockets was measured by Diamond probe/Perio 2000 system, followed by probing using Williams periodontal probe to get the records of probing depth (PD). Based on the above examination results, 4 - 8 sites with PD > or = 5 mm and/or pS > 0 were selected for the following longitude observation in each patient. The plaque index (PLI), bleeding index (BI), clinical attachment level (CAL) of the target site were recorded. The same examination was repeated during the recalling time of 6 weeks, 3 and 6 months after the initial periodontal therapy. RESULTS: VSC levels are significantly correlated with the numbers of sites with pS > 0 (r = 0.592, P < 0.001) and pS value. pS values were positively correlated with BI at low level during the maintenance time of 6 weeks, 3 and 6 months (r = 0.183, 0.411, 0.350, P < 0.05) respectively. After the initial therapy pS, PD, CAL, BI, PLI and VSC in oral cavity significantly improved at 6 weeks (P < 0.001) and further improved and kept stable at 3 and 6 months. CONCLUSIONS: pS reflects the sulfide levels in pockets with site specificity and may be considered as objective parameter to evaluate the treatment effect, and to indicate the early inflammation in periodontal tissue during the maintenance period.

[Comparative study of the effects of removing plaque by two toothbrushing methods].

OBJECTIVE: To compare the effects of removing plaque by two toothbrushing methods. METHODS: Forty subjects were chosen to take part in the randomized, examiner-blind, crossover study. RESULTS: Modified Bass method has better effect of removing plaque, especially that at the central margin than Vertical method (P<0.05). CONCLUSION: Modified Bass method needs to be recommended.

[Effect of spirochetes and porphyromonus gingivalis on oral malodor].

OBJECTIVE: To assess the effect of Spirochetes and Porphyromonus gingivalis (Pg) on the production of volatile sulfur compounds (VSCs) and oral malodor, respectively. METHODS: 117 systemically healthy periodontitis patients were divided into two groups according to organoleptic rating (OR) by organoleptic method: 85 subjects with oral malodor (halitosis group, HG) and 32 cases without oral malodor (no-halitosis group, NHG). VSCs measurements were made with halimeter. Subgingival plaques and tongue coating were taken to calculate the proportion of Spirochetes (with 2% Congo Red Smears, S%) and the amounts of Pg (with indirect immunofluorescence method). The examination will be repeated in 46 HG cases after periodontal therapy. RESULTS: S% in PD < 4 mm sites of HG was significantly higher than that in NHG (P < 0.01). S% in PD >or= 4 mm sites and tongue coating, Pg in all three sites were not different between two groups. In HG, OR and VSCs levels were correlated with S% in tongue coating (P < 0.01, P < 0.05) and PD < 4 mm sites (P < 0.05), and not correlated with S% in PD >or= 4 mm sites. OR was related to Pg in PD >or= 4 mm sites (P < 0.05) and there was no relationship between OR and Pg in tongue coating and PD < 4 mm sites. VSCs levels was not correlated with Pg in all three sites. S% in tongue coating and subgingival plaque, Pg in subgingival plaque, OR and VSCs levels were significantly reduced after periodontal therapy (P < 0.01). CONCLUSIONS: The direct relationship of Spirochetes and Pg respectively to bad breath was not found obviously. But Spirochetes is one of the microorganism on oral malodor. Periodontal therapy can improve oral malodor.