Long-Term Mastication Changed Salivary Metabolomic Profiles.

Saliva is an ideal biofluid for monitoring oral and systemic health. Repeated mastication is a typical physical stimulus that improves salivary flow and oral hygiene. Recent metabolomic studies have shown the potential of salivary metabolomic components for various disease monitoring systems. Here, we evaluated the effect of long-term mastication on salivary metabolomic profiles. Young women with good oral hygiene (20.8 ± 0.3 years, n = 17) participated. They were prohibited from chewing gum during control periods (4 weeks each) and were instructed to chew a piece of gum base seven times a day for 10 min each time during the intervention period. Paired samples of unstimulated whole saliva collected on the last day of the control and intervention period were compared. Liquid chromatography−time-of-flight mass spectrometry successfully quantified 85 metabolites, of which 41 showed significant differences (p < 0.05, Wilcoxon paired test corrected by false discovery rate). Except for a few metabolites, such as citrate, most metabolites showed lower concentrations after the intervention. The pathways related to glycogenic amino acids, such as alanine, arginine, and glutamine, altered considerably. This study suggests that long-term mastication induces unstimulated salivary component-level changes.

Comparison of the effects of ultrasound toothbrushes with different frequencies on oral hygiene: A randomized-controlled clinical trial.

BACKGROUND: The purpose of this study was to examine whether high-frequency ultrasound toothbrushes have different effects on oral hygiene. METHODS: Fifty first-year dental hygiene students were randomly divided into three groups using ultrasound toothbrushes with different frequencies (1.6, 3.2 and 4.8 MHz) twice a day (3-min sessions) for 8 weeks. Plaque index (PlI) and gingival index (GI) scores were assessed at 4 and 8 weeks. RESULTS: Changes in GI scores from baseline to 8 weeks tended to differ among the groups (p = 0.0862). The GI was significantly lower in the 3.2 and 4.8 MHz groups at 8 weeks (3.2 MHz group: p < 0.01, 4.8 MHz group: p < 0.05). At 4 weeks, the GI was significantly lower in the 3.2 MHz group (p < 0.05) and tended to be lower in the 4.8 MHz group (p = 0.07). The PlI was significantly lower in the 3.2 MHz group at 8 weeks (p < 0.01) and tended to be lower in the 1.6 and 4.8 MHz groups (1.6 MHz: p = 0.07, 4.8 MHz: p = 0.05). In addition, the PlI was significantly lower in the 4.8 MHz group at 4 weeks (p < 0.05). No significant differences in the changes in any measurements were observed among the groups. CONCLUSIONS: The results of this study indicated that ultrasound toothbrushes with different frequencies probably have different effects on oral hygiene. However, it is difficult to conclude strongly that higher frequency ultrasound toothbrushes are more effective as there were some limitations.

Effects of Chewing Gum Base on Oral Hygiene and Mental Health: A Pilot Study.

The purpose of the present study was to clarify the long-term effects of frequent chewing of unflavored and odorless gum (hereafter, gum base) on oral hygiene and mental health. This single-arm study, which started with a 4-week control and ended with a 4-week intervention period, was conducted in two phases: one in 2017 and one in 2018. The participants comprised 36 dental hygiene students (17 in 2017, 19 in 2018). During the intervention period, all participants were required to chew a piece of gum base 7 times a day for 10 min each time. The unstimulated salivary flow rate and masticatory efficiency were measured and chewing number counted. Two questionnaires －the Profile of Mood States, second edition (POMS2) and the 30-item General Health Questionnaire (GHQ-30)－ were administered to assess mental health. In both phases, the unstimulated salivary flow rate showed a significant increase after the intervention period (p<0.05). In 2017, the GHQ-30 scores and masticatory efficiency showed a tendency toward a negative correlation after the intervention period (r=－0.4647, p=0.06). In 2018, a significant negative correlation was observed between chewing number and the POMS2 scores after the intervention period (r=－0.6296, p<0.01). These findings suggest that frequent chewing of gum base increases unstimulated salivary flow rate. However, no significant change was observed in the mental health.

Effects of Ultrasonic Debridement on Oral Hygiene Status.

The aim of this randomized-controlled, single-blinded study was to compare the effects of mechanical tooth cleaning (MTC) and ultrasonic debridement (UD) on oral hygiene status in healthy young adults. Thirty-seven participants (mean age: 20.3±0.62 years) were divided into 3 groups after pre-examination: group A, receiving MTC; B, receiving MTC+UD using a universal insert (UDUI); and C, receiving MTC+UD using a probe-shaped insert (UDPI). All participants were required to abstain from oral hygiene for 24 hours after the allocated intervention, after which they were examined. A masked examiner determined the Quigley-Hein plaque index (PlI) and Silness and Löe gingival index (GI) scores before the interventions and after 24 hours of non-brushing. A significant increase in the PlI score was observed in group A (p<0.001) in comparison with that in group B (A: 0.311±0.26; B: -0.01±0.33; C: 0.13±0.27; p<0.05). A significant decrease in the GI score was observed in groups B and C (p<0.05), and the change in this score in group C significantly differed from that in group A or B (A: -0.04±0.25; B: -0.13±0.17; C: -0.33±0.2; p<0.05). Only MTC was insufficient to prevent plaque formation over a 24-hour period of non-brushing and decrease the GI score. Ultrasonic debridement was more effective in preventing plaque formation and decreasing the GI score, regardless of the type of insert used. The present results suggest that UD should be included as an important procedure in the provision of professional oral prophylaxis and that UDPI is as efficient for cleaning as UDUI.

Factors Associated with Number of Present Teeth in Adults in Japanese Urban City.

The purpose of this study was to identify which factors were associated with number of present teeth (PT) in older adults as their clarification might contribute to maintaining the number of PT in this population. These factors were investigated by means of a questionnaire on oral health condition, general health behavior, and anamnesis of diabetes mellitus together with a dental examination. Data were obtained from a total of 7,741 Japanese subjects (2,623 males and 5,118 females), all of whom were aged 40, 50, or 60 years. Significant differences were observed in the mean number of PT between a positive or negative response to questions on anamnesis of diabetes mellitus, current smoking, and having loose teeth in all age groups in males; significant differences were also observed for current smoking, lower intake of dairy milk products, having loose teeth, no experience of tooth brushing instruction, and poor oral hygiene status in all age groups in females. Stepwise logistic regression analysis revealed having loose teeth (odds ratio [OR], 1.82), gingival swelling (OR, 1.40), an anamnesis of diabetes mellitus (OR, 1.72), current smoking (OR, 1.86), lower intake of dairy milk products (OR, 1.22), preference for salty seasonings (OR, 1.23), frequent sweet intake (OR, 1.29), no experience of tooth brushing instruction (OR, 1.38), and poor oral hygiene (OR, 2.04) as significant risk factors for the number of PT being <24 after adjusting for age and sex. These results indicate that an anamnesis of diabetes mellitus, a history of smoking, the presence of loose teeth, and poor oral hygiene status in a self-reported evaluation of oral health might correlate with <24 PT in older adults.

Relationship between General Health, Lifestyle, Oral Health, and Periodontal Disease in Adults: A Large Cross-sectional Study in Japan.

The aim of this study was to investigate how general health, oral conditions, and lifestyle were associated with periodontal disease in adults, as clarifying this relationship may be useful in preventing periodontal disease. Medical checkups were conducted on individuals aged 40, 50, or 60 years. Data were obtained for analysis on a total of 36,110 patients (men, 12,784; women, 22,896). A stepwise logistic regression model was used to calculate the odds ratio (OR) for patients who were ≥code 3 according to the Community Periodontal Index (CPI). Approximately 40, 60, and 70% of men aged 40, 50, and 60 years, respectively, had a CPI score of ≥3. There were 10% fewer women than men at each age. Stepwise logistic regression revealed a BMI score of ≥30 kg/m2(OR, 1.44; 95% confidence interval [95%CI], 1.20-1.73); systolic blood pressure of ≥140 mmHg (OR, 1.09; 95%CI, 1.02-1.18); a fasting blood sugar level of ≥110 mg/dl (OR, 1.17; 95%CI, 1.04-1.30); high-density lipoprotein cholesterol level of <40 mg/dl (OR, 1.21; 95%CI, 1.06-1.37); smoker (OR, 1.59; 95%CI, 1.48-1.71); drinking ≥3 cups of Japanese sake per day (OR, 1.09; 95%CI, 1.05-1.14); use of salts for seasoning (OR, 1.17; 95%CI, 1.07-1.28); and fair and poor oral hygiene (OR, 2.27; 95%CI, 2.08-2.47) as significant risk factors for a CPI score of ≥3. These results suggest that smoking, oral hygiene status, and factors associated with metabolic syndrome are associated with periodontitis. This indicates that health guidance on tooth brushing, the importance of quitting smoking, and control of obesity may be effective in preventing the development of periodontal disease in adults.

Metabolic Syndrome, Lifestyle, and Dental Caries in Japanese School Children.

The number of children with Metabolic Syndrome (MetS) has recently been increasing in Japan. Few studies have investigated the relationship between MetS and oral health. The aim of this study was to investigate the association between MetS, lifestyle, and oral health status in school children. Our goal is to utilize these results in health education aimed at preventing the onset of MetS in school children and adults. A total of 689 Japanese children (365 boys and 324 girls) aged between 10 and 13 years were examined and waist circumference (WC), ratio of WC to height, blood pressure, fasting blood sugar (FBS), high density lipoprotein-cholesterol, and triglyceride values determined together with oral health status, including dental caries experience (DMFT). The results revealed that 6.5% of the children fell under the health board recognized "MetS or high risk of MetS" (MetS/HR) classification. A total of 140 (20%) children had a high Streptococcus mutans count. The mean WC, FBS, and DMFT values were significantly greater in children with a high salivary S. mutans count (p<0.05). Multiple logistic regression analysis revealed a statistically significance association between MetS/HR, non-breakfast eaters (odds ratio (OR): 2.70), no regular exercise (OR: 2.60), and a high salivary S. mutans count (≥10(5) CFU/ml; OR: 2.18; p<0.05). The present results indicate that lifestyle and salivary S. mutans count could be useful in screening children for MetS/HR. These variables may be useful in targeting interventions aimed at preventing MetS in school children.

Loss of teeth in positions mesially adjacent to implant-supported fixed dentures: a retrospective clinical survey.

The aim of this study was to investigate the loss of teeth in positions mesially adjacent to implant-supported fixed dentures (IFDs) after insertion of IFDs in unilateral free-end edentulous spaces in the mandible at dental clinics. There were a total of 157 adjacent teeth. Nine adjacent teeth (5.73%, 9 of 157), 9 opposing teeth (2.59%, 9 of 348), 38 posterior teeth (1.93%, 38 of 1,964), and 3 anterior teeth (0.22%, 3 of 1,380) were lost during the observation period. The percentage of lost adjacent teeth was higher than that of posterior teeth (P = .002). Teeth in positions adjacent to the IFDs require more attention than other remaining teeth.

Grinding efficiency of abutment tooth with both dentin and core composite resin on axial plane.

The purpose of this study was to evaluate grinding efficiency in abutment teeth comprising both dentin and core composite resin in the axial plane. Grinding was performed over 5 runs at two loads (0.5 or 0.25 N) and two feed rates (1 or 2 mm/sec). The grinding surface was observed with a 3-D laser microscope. Tomographic images of the grinding surfaces captured perpendicular to the feed direction were also analyzed. Using a non-ground surface as a reference, areas comprising only dentin, both dentin and core composite resin, or only core composite resin were analyzed to determine the angle of the grinding surface. Composite resins were subjected to the Vickers hardness test and scanning electron microscopy. Data were statistically analyzed using a one-way analysis of variance and multiple comparison tests. Multiple regression analysis was performed for load, feed rate, and Vickers hardness of the build-up material depending on number of runs. When grinding was performed at a constant load and feed rate, a greater grinding angle was observed in areas comprising both dentin and composite resin or only composite resin than in areas consisting of dentin alone. A correlation was found between machinability and load or feed rate in areas comprising both dentin and composite resin or composite resin alone, with a particularly high correlation being observed between machinability and load. These results suggest that great caution should be exercised in a clinical setting when the boundary between the dentin and composite resin is to be ground, as the angle of the grinding surface changes when the rotating diamond point begins grinding the composite resin.

Sex- and age-based differences in single tooth loss in adults.

The aim of this study was to investigate sex- and age-based differences in single tooth loss in adults. The data were obtained from the results of a periodontal disease examination carried out under a health promotion law in a city in Japan in 2005. Baseline data from a total of 3,872 participants aged 40 or 60 years comprising 1,302 men and 2,570 women were available. Only participants with 27 present teeth were eligible for inclusion in the analysis, giving a total of 218 men and 428 women. Third molars were excluded from the study. The bilateral total of each type of tooth was obtained. The mandibular first molar was missing in 26.7% of the men and 36.2% of the women among 40-year-olds and 35.3% of the men and 29.8% of the women among 60-year-olds. The mandibular second molar was missing in 14.7% of the men and 12.5% of the women among 40-year-olds, and 17.6% of the men and 18.4% of the women among 60-year-olds. Significant differences were observed between men and women in the mandibular second premolars and first molars among 40-year-olds. These results suggest that we need to pay more attention to individual teeth which are at particularly high risk for tooth loss, namely the mandibular first and second molars, and especially the mandibular first molars in middle-aged women.

Cohort study on incidence of coronal and root caries in Japanese adults.

The purpose of this study was to investigate the incidence of coronal and root caries in participants aged 20-59 years in Japan. The participants comprised 118 men and 23 women undergoing a re-examination 5 years after an initial examination. Lesions were classified as gingival recession, decayed root caries, or filled surfaces. The rates of incidence of coronal caries over the 5 years were 87% in women aged 20-29 years, 77% in men aged 20-29 years, 62% in men aged 30-39 years, 64% in men aged 40-49 years, and 60% in men aged 50-59 years. The rates for those observed to be at risk for the incidence of root caries were 25% for women aged 20-29 years, 16% for men aged 20-29 years, 11% for men aged 30-39 years, 43% for men aged 40-49 years, and 35% for men aged 50-59 years. The distribution for the number of new coronal and root caries lesions was 68.8% and 24.1%, respectively. Univariate logistic regression analyses for new coronal caries revealed that the risk factors were age group at baseline (OR=0.702, p=0.0440), number of coronal decayed and filled surfaces at baseline (OR=2.893, p=0.0107), and number of sound teeth at baseline (OR=3.381, p=0.0013). Moreover, univariate logistic regression analyses for new root caries revealed that the risk factors were age group at baseline (OR=1.787, p=0.0039), presence or absence of gingival recession at baseline (OR=3.288, p=0.0062), and presence or absence of root decayed and filled surfaces at baseline (OR=11.00, p<0.0001). It was concluded from these results that the target of caries prevention in adults should not only be focused on root surfaces, especially in those aged 40 years or over, but also on the coronal surfaces of the dentition in those in their twenties.

Loss of teeth opposing implant-supported prostheses in the posterior mandible: a retrospective survey in dental clinics.

PURPOSE: The main aim of this study was to investigate the loss of maxillary teeth opposing mandibular implant-supported prostheses (ISPs) placed at dental clinics. MATERIALS AND METHODS: Participating dentists were asked to provide information on implant procedures they had undertaken between January 1, 1990, and December 31, 2009. Data were requested for procedures in which implants were inserted into only one side of the mandible in posterior regions and no implants were inserted in other regions. RESULTS: Data on a total of 383 patients were analyzed. Participants in this study consisted of 170 men and 213 women ranging from 20 to 78 years of age (mean age, 51.0 years). Natural teeth were divided into three groups: opposing teeth (teeth opposing ISPs), control teeth (teeth of the same type as the opposing teeth but on the other side of the maxilla), and other teeth. The mean observation period was 72 months. One hundred six teeth were lost during the observation period. Fourteen opposing teeth were lost (1.72%, 14/816), 15 control teeth were lost (1.84%, 15/816), and 77 other teeth were lost (0.98%, 77/7,891). The percentage of opposing teeth lost was significantly higher than that of other teeth. However, there was no difference in the rates of loss of opposing and control teeth. CONCLUSION: ISPs in posterior mandibular regions are not a risk factor for the loss of opposing teeth.

Risk factors affecting third molar autotransplantation during 5 and 10 years.

The aim of this study was to investigate risk factors affecting 5- and 10-year survival in autotransplantation of third molars with complete root formation at dental clinics. Participating dentists were requested to provide information on transplantations performed between 1 January 1990 and 31 December 2009. After data screening and elimination, 183 teeth in 171 men aged 20-72 years (mean, 44.8 years) and 205 teeth in 189 women aged 20-74 years (mean, 42.0 years) were included in the study. A single-factor analysis using the log-rank test revealed that the following factors had a significant influence (p<0.05) on 5-year survival in transplanted teeth in men: recipient site in the maxilla and fewer than 25 present teeth; those for 10-year survival, on the other hand, were recipient site tooth extraction due to periodontal disease, recipient site in the maxilla, fewer than 25 present teeth, and Eichner index Group B1 to C. Cox regression analysis revealed that the odds ratio for 5-year survival for recipient site in the maxilla was 2.873 (95% CI, 1.073-7.695), while that for 10-year survival was 3.713 (95% CI, 1.601-8.609) for recipient site extraction due to periodontal disease, 2.190 (95% CI, 1.021-4.700) for recipient site in the maxilla, and 3.110 (95% CI, 1.470-6.581) for fewer than 25 present teeth. In women, the log-rank test indicated experience of less than 10-year in performing treatment as a significant factor (p <0.05) in 5-year survival. These results suggest that medium-term survival in transplanted teeth is influenced by operational risk factors in women, while long-term survival in transplanted teeth is influenced by individual oral status in men.

Fundic gland polyps accurately predict a low risk of future gastric carcinogenesis.

OBJECTIVES: Few reports have analyzed the clinical importance of sporadic fundic gland polyps (FGPs). The aim of this study was to investigate the relationship between sporadic FGPs and condition of the gastric mucosa stratified by serum pepsinogen levels and Helicobacter pylori antibody level. METHODS: Three hundred and seventy-five subjects undergoing gastrointestinal endoscopy were enrolled. Subjects on proton pump inhibitors were excluded. Pathologically proven FGPs, and other endoscopic findings (reflux esophagitis, gastric and duodenal ulcer) were examined and serum pepsinogen levels, H. pylori antibody concentration and gastric juice pH were measured simultaneously. Subjects with normal serum pepsinogen and negative H. pylori antibodies were defined as having "low risk" stomachs, suggesting low risk of gastric carcinogenesis. RESULTS: Of the 375 subjects, 44 showed FGPs. The prevalence of "low risk" stomach in subjects with and without FGPs was 98% and 48%, respectively. Multivariable logistic regression analysis indicated three variables as independent factors positively associated with "low risk" stomachs: FGPs (odds ratio [OR] 38.6), reflux esophagitis (OR 4.8), and age<60 years (OR 1.89). Gastric juice pH, which is associated with mucosal atrophy grade and low pH indicates less mucosal atrophy, was significantly lower in subjects with (1.64 ± 0.64) than without FGPs in "low risk" (1.94 ± 1.12) and "high risk" stomachs (3.99 ± 2.31). CONCLUSIONS: Sporadic FGPs tend to be related to the least atrophic mucosa among non-gastric atrophy subjects without H. pylori infection, and can be used as predictors of a low risk of gastric carcinogenesis.

Effect of clinical factors on bacterial contamination of bone chips collected during implant surgery.

PURPOSE: The objective of this study was to investigate the relationship between various clinical factors and bacterial contamination of bone chips (BC) collected during dental implant surgery and to elucidate how bacterial contamination might be minimized. MATERIALS AND METHODS: Implants were installed in 55 partially edentulous patients (36 men and 19 women), among whom the relationship between various clinical factors and bacterial contamination of BC collected by bone trap was investigated in 37. The effect of rinsing with a saline on BC was determined in 18 patients. Number of contaminating microorganisms was expressed as colony-forming units (CFUs). RESULTS: CFUs in the maxilla were lower than those in the mandible (P < 0.01). CFUs at the incisors or canines were lower than those at the premolars or molars (P < 0.01). Logistic regression analysis revealed a relationship between average bacterial count and duration of surgery (odds ratio, 1.046; 95% CI, 1.012-1.081). Rinsing of BC reduced bacterial contamination. CONCLUSION: Duration of surgery is a major clinical factor affecting contamination risk in BC, and rinsing of BC with a sterile saline solution reduces bacterial number.

Estimated percentile curves of occluding pairs in an adult population.

The purpose of this study was to provide the estimated percentile curves of occlusal pairs (OPs) in adults for use in oral health instruction. Data on number of present teeth (PT) were obtained from the National Report on the Survey of Dental Disease in 2005. Data from 1,535 males and 2,248 females, ranging in age from 18 to 82, were analysed. The mean number of OPs were used from our previous report. In that report we can be estimated OPs from the number of PT. In this study, PT data were replaced by the mean number of OPs. Estimated percentile curves in males, the 10th percentile of OPs was 13.7 at 60 years of age and 12.5 at 70. The 50th percentile of OPs was 12.2 at 50 years of age, 11.2 at 60 and 5.4 at 70. The 90th percentile of OPs was 7.6 at 50 years of age, 2.1 at 60 and 0 at 70. There appeared to be a cut off point after 10 OPs where the 50th to 97th percentile curves of OPs dropped off rapidly. In females, the 10th percentile of OPs was 13.4 at 60 years of age and 12.7 at 70. The 50th percentile of OPs was 11.5 at 50 years of age, 10.2 at 60 and 6.2 at 70. The 90th percentile of OPs was 7.1 at 50 years of age, 2.4 at 60 and 0 at 70. In females again the percentile curves dropped off after 10 OPs. Our results suggest that the loss of OPs may be accelerated when the number of OPs drops below 10. This means that patients need at least 10 OPs in order to maintain a stable oral status. The estimated percentile curves given in this study should be made available for use in adult oral health education.

Survival rate in autotransplanted premolars with complete root formation: a retrospective clinical survey.

The purpose of this study was to analyze the survival rate in autotransplanted premolars with complete root formation in dental clinics. Participating dentists were requested to provide information on transplantations they had undertaken between 1 January 1990 and 31 December 2010. Data on a total of 708 teeth from 637 patients were collected. Data for other tooth types and for teeth with incomplete root formation were eliminated. In this study, data on 40 teeth in 35 patients were analyzed. Participants consisted of 17 men and 18 women ranging from 24 to 79 years in age (mean age, 43.7 years). The cumulative survival rate was 100% at the 5-year mark and 72.7% at 10 years, as calculated by the Kaplan-Meier method. Single-factor analysis revealed that "transplanted to the molar regions" was a significant risk factor (p<0.05) influencing the survival of transplanted teeth. However, a Cox regression analysis showed no significance. The results of this study suggest that, in cases where there is a suitable donor tooth and the oral condition is good, premolar autotransplantation is a viable treatment option, even when there is complete root formation in the donor teeth.

Procedures for treating spaces vacated by loss of transplanted teeth.

The main reasons for loss of autotransplanted teeth are different from those involved in natural teeth loss. The aim of this study was to investigate which procedures were employed to treat spaces vacated when autotransplanted teeth were lost. Participating dentists were requested to provide information on transplantations they had undertaken. A total of 614 teeth in 552 patients (37 dentists) ranging in age from 17 to 79 years (mean age: 44.1 years) were examined. A total of 102 transplanted teeth were lost during the observation period. Procedures for treatment of spaces vacated were not influenced by main reason for transplanted tooth loss. The procedure used to treat depended on the original prosthodontic treatment of the transplanted teeth. For single crowns, the spaces were left empty (33.9%) or replaced by bridge work (30.5%), implants (20.3%), or dentures (10.2%). For single crowns in the upper and lower second molar regions, the spaces were usually left empty (upper 100%, lower 71.4%), while for those in the upper and lower first molar regions, the spaces were often replaced by bridge work (upper 41.7%, lower 50.0%). For bridge abutments, spaces were replaced by dentures (42.9%), implants (33.3%), or left empty (14.3%), and in the lower second molar region, they were mostly replaced by implants (5 cases, 41.7%). For most denture abutment cases, the spaces were replaced by dentures (88.9%). During the survival period of the transplanted teeth, the masticatory burden on the other teeth is reduced and the adjacent teeth are supported by the transplanted tooth. Even if transplanted teeth are eventually lost, traditional procedures can be performed to fill the vacated space.

Nonsurgical recovery of interdental papillae under supportive periodontal therapy.

We observed nonsurgical improvement of interdental papillae in a patient undergoing supportive periodontal therapy. The patient was a 47-year-old Japanese man presenting with widespread gingival recession at Daniele's papilla presence index level 3 and Miller Class I recession affecting the facial aspect of tooth number 42. Initial periodontal therapy for periodontitis was performed, included oral hygiene instruction, scaling and root planing, resulting in a reduction in inflammation. Use of an interdental brush was then suspended to allow the interdental papillae to recover. The type of toothbrush and tooth brushing method were checked repeatedly. Mechanical debridement was performed every 2 to 3 months. A gradual improvement was observed in recession of the interdental papillae over a period of several years together with coronal regrowth of the gingival margin.

Relationship between Eichner Index and number of present teeth.

The aim of this study was to determine the percentage of participants in each of the six Eichner Index groups by number of present teeth (PT). The data were obtained from a periodontal disease examination carried out under a health promotion law in a city located northeast of Tokyo, Japan, in 2005. Data from a total of 1,549 (524 male and 1,025 female) 60-year-old participants were analyzed in this study. Number of occlusal supports was counted by analyzing dental charts. The Eichner Index was used to group the participants into six groups based on distribution of occlusal support teeth. The percentage of patients in Group A with 24 PT was 31.4%; none in Group A had fewer than 19 PT. The percentage in Groups A, B1, and B2 with between 20 and 28 PT was above 50%; the number of participants in these groups with fewer than 20 PT decreased rapidly. Those with fewer than 16 PT were almost found in Groups B3, B4 and C. Only a few patients in Group C had between 10 and 14 PT; those with fewer than 9 PT were only found in Groups B4 or C. Based on these results, the Eichner Index category of a given participant can be estimated from number of PT.