Periodontal disease and pneumonia mortality in haemodialysis patients: A 7-year cohort study.

AIM: To evaluate the association between periodontal disease and pneumonia mortality in haemodialysis patients. MATERIALS AND METHODS: This prospective cohort study included 211 patients (mean age, 64.4 years) undergoing haemodialysis at a single medical centre. The patients underwent a baseline clinical dental examination in 2008 and were then followed up until July 2015. Periodontal disease was defined as the presence of clinical attachment loss of ≥4 mm in ≥30% of the probed sites. The primary endpoint, that is death from pneumonia, was determined by reviewing death certificates and was analysed using the competing-risks regression model. RESULTS: At baseline, 92 patients (43.6%) had periodontal disease. The median follow-up period was 84 months (interquartile range, 36-86 months). Of the 68 deaths that occurred, 21 were from pneumonia. The multivariable competing-risks regression model showed that periodontal disease was significantly associated with death from pneumonia (adjusted subhazard ratio, 3.49; 95% confidence interval, 1.14-10.64), after adjusting for other baseline health characteristics. CONCLUSIONS: The results of this study suggest that periodontal disease is independently associated with pneumonia mortality in haemodialysis patients. Future studies evaluating the potential effect of oral interventions for periodontal health improvement on pneumonia in haemodialysis patients would be of great interest.

Evaluating GPT-4V's performance in the Japanese national dental examination: A challenge explored.

Background/purpose: Rapid advancements in AI technology have led to significant interest in its application across various fields, including medicine and dentistry. This study aimed to assess the capabilities of ChatGPT-4V with image recognition in answering image-based questions from the Japanese National Dental Examination (JNDE) to explore its potential as an educational support tool for dental students. Materials and methods: The dataset used questions from the JNDE, which was conducted in January 2023, with a focus on image-related queries. ChatGPT-4V was utilized, and standardized prompts, question texts, and images were input. Data and statistical analyses were conducted using Qlik Sense® and GraphPad Prism. Results: The overall correct response rate of ChatGPT-4V for image-based JNDE questions was 35.0 %. The correct response rates were 57.1 % for compulsory questions, 43.6 % for general questions, and 28.6 % for clinical practical questions. In specialties like Dental Anesthesiology and Endodontics, ChatGPT-4V achieved correct response rates above 70 %, while response rates for Orthodontics and Oral Surgery were lower. A higher number of images in questions was correlated with lower accuracy, suggesting an impact of the number of images on correct and incorrect responses. Conclusion: While innovative, ChatGPT-4V's image recognition feature exhibited limitations, especially in handling image-intensive and complex clinical practical questions, and is not yet fully suitable as an educational support tool for dental students at its current stage. Further technological refinement and re-evaluation with a broader dataset are recommended.

The potential positive effect of periodontal treatment on brain function activity using functional magnetic resonance imaging analysis.

Background/purpose: There are reports on the relationship between periodontal treatment and the whole body. The purpose of the present study was to investigate the effect of periodontal initial treatment on brain function activity by improving periodontal tissue and the occlusal status of subjects with periodontitis. Materials and methods: The subjects were 13 patients with periodontitis. Following the patient's informed written consent, the periodontal initial treatment provided to the patient included tooth brushing instruction, scaling and root planning, however, occlusal adjustment was not performed at this stage. Periodontal examination, occlusal force examination and fMRI results were also evaluated at the initial and the reevaluation examinations. Results: After the periodontal initial treatment had been performed, periodontal tissue had significantly improved. In addition, cerebral blood flow in the insula and primary motor cortex was also improved, as confirmed by fMRI. Conclusion: This result suggests that the periodontal ligament has recovered and the periodontal ligament neuron have been further subjected to clenching in the insula.

Association between oral frailty and nutritional status among hemodialysis patients aged ≥50 years.

AIM: Malnutrition is a prevalent health issue among hemodialysis patients. Oral frailty, a condition characterized by impairments in multiple oral health aspects and functions, has been associated with nutritional status in the general population. We aimed to determine whether oral frailty was associated with nutritional status in hemodialysis patients aged ≥50 years. Our secondary aim was to determine the prevalence of oral frailty in this population. METHODS: This cross-sectional study included hemodialysis patients who were admitted to a single medical center. According to the Oral Frailty 5-item Checklist, oral frailty is characterized by the presence of two or more of the following criteria: (i) fewer teeth, (ii) difficulty in chewing, (iii) difficulty in swallowing, (iv) dry mouth, and (v) low articulatory oral motor skills. Patients' nutritional status was assessed using the Geriatric Nutritional Risk Index (GNRI). Multivariable ordinal logistic regression analysis was performed to assess the association between oral frailty and nutritional status (classified into three categories according to the GNRI: >98, 92-98, and <92). RESULTS: In total, 152 hemodialysis patients (55 women and 97 men) with a mean age of 70.4 years were included. The prevalence of oral frailty was 61.2%. After adjusting for health characteristics and sociodemographic background, oral frailty was associated with poor nutritional status according to the GNRI (odds ratio = 2.04, 95% confidence interval = 1.02-4.09). CONCLUSIONS: In this study, approximately 60% of hemodialysis patients aged ≥50 years exhibited oral frailty, and hemodialysis patients with oral frailty had poor nutritional status according to the GNRI. Geriatr Gerontol Int 2024; ••: ••-••.

Monitoring the prevalence of viable and dead cariogenic bacteria in oral specimens and in vitro biofilms by qPCR combined with propidium monoazide.

BACKGROUND: Streptococcus mutans and Streptococcus sobrinus are associated with the development of dental caries in humans. However, previous diagnostic systems are unsuitable for monitoring viable cell numbers in oral specimens. Assessing the relationship between the numbers of viable and dead bacterial cells and oral status is important for understanding oral infectious diseases. Propidium monoazide (PMA) has been reported to penetrate dead cells following membrane damage and to cross-link DNA, thereby inhibiting DNA amplification. In the present study, we established an assay for selective analysis of two viable human cariogenic pathogens, S. mutans and S. sobrinus, using PMA combined with real-time PCR (PMA-qPCR). RESULTS: We designed species-specific primer sets for S. mutans and S. sobrinus, generated standard curves for measuring cell numbers, and evaluated the dynamic range of the assay. To determine the effectiveness of the assay, PMA was added to viable and autoclave-killed cell mixtures. PMA treatment effectively prevented DNA amplification from dead cells. No amplification of DNA from dead cells was observed in these organisms. In addition, we applied this assay to analyze viable cell numbers in oral specimens. A significant correlation was found between the number of viable S. mutans cells in saliva and that in plaque among caries-free patients, whereas no correlation was observed between saliva and carious dentin. The total and viable cell numbers in caries-positive saliva were significantly higher than those in caries-free saliva. Finally, we analyzed the usefulness of this assay for in vitro oral biofilm analysis. We applied PMA-qPCR for monitoring viable S. mutans cell numbers in vitro in planktonic cells and oral biofilm treated with hydrogen peroxide (H2O2). In planktonic cells, the number of viable cells decreased significantly with increasing H2O2 concentration, whereas only a small decrease was observed in biofilm cell numbers. CONCLUSIONS: PMA-qPCR is potentially useful for quantifying viable cariogenic pathogens in oral specimens and is applicable to oral biofilm experiments. This assay will help to elucidate the relationship between the number of viable cells in oral specimens and the oral status.

Neutral endopeptidase regulates neurogenic inflammatory responses induced by stimulation of human oral keratinocytes with bacterial lipopolysaccharide and nicotine.

Neutral endopeptidase (NEP) is present on various epithelial cells and inactivates numerous physiologically active peptides. Neutral endopeptidase may regulate proinflammatory signals in oral mucosal epithelium. However, the function of NEP in oral mucosal epithelium is unknown. The present study investigated the action of NEP upon proinflammatory signals on human oral keratinocytes and the influence of endothelin-converting enzyme (ECE)-1, an enzyme similar to NEP, on the functions of NEP. Oral keratinocytes were cultured in medium containing inflammatory inducers [lipopolysaccharide (LPS) and nicotine], NEP inhibitors, and ECE-1/NEP inhibitors, either alone or in combination. The concentrations of substance P (SP) and interleukin-1ß (IL-1ß) were measured in the supernatant. Additionally, the concentrations of SP and IL-1ß were measured in the supernatant of cells incubated with LPS or nicotine after transfection with NEP small interfering RNA (siRNA). The concentrations of SP and IL-1ß were significantly increased in cells incubated with NEP inhibitors and, to a lesser extent, in cells incubated with ECE-1/NEP inhibitors, compared with controls (cells incubated with LPS or nicotine alone). The concentrations of SP and IL-1ß in cells transfected with NEP siRNA were significantly augmented compared with controls. In conclusion, the present study demonstrated that NEP down-regulated the levels of SP and IL-1ß produced from human oral keratinocytes, although ECE-1 may be partly related to the down-regulation.

Association between tooth loss and orodigestive cancer mortality in an 80-year-old community-dwelling Japanese population: a 12-year prospective study.

BACKGROUND: A growing body of evidence has indicated a possible association between oral and gastrointestinal (orodigestive) cancers and periodontal disease or tooth loss. However, the evidence remains contradictory. This study investigated whether tooth loss, which is indicative of poor oral health and a potential source of oral infections, is associated with death from orodigestive cancer. METHODS: The study included 656 subjects in Fukuoka prefecture, Japan, who were 80 years old at baseline in 1998. All subjects underwent oral clinical examination and answered a questionnaire to determine their background characteristics. Cause of death over the 12-year follow-up was recorded from the registers at the Public Health Centers and classified according to the WHO International Classification of Diseases. Statistical analysis of associations was performed using Kaplan-Meier and Cox multivariate regression analyses. RESULTS: A significant association was observed between tooth loss (continuous variable) and cancer death (hazard ratio (HR): 1.03, 95% confidence interval (CI): 1.00-1.07), after adjustment for potential confounders, including sex and smoking status. However, that association became insignificant in the fully adjusted model. On the other hand, tooth loss was significantly associated with orodigestive cancer (HR: 1.06, 95% CI: 1.01-1.13), even in the fully adjusted model including place of residence as a part of socioeconomic status. CONCLUSIONS: This study provides the first evidence in a prospective study in a Japanese population that tooth loss is associated with increased orodigestive cancer mortality, although the causality remains unclear.

Activities of daily living dependency and disease-specific mortality during 12-year follow-up in an 80-year-old population.

BACKGROUND AND AIMS: Although total mortality is likely to be higher in elderly individuals with frailty or impaired activities of daily living (ADL), little is known about the relationships between disease-specific mortality and ADL dependency in the elderly. Therefore, we examined whether 12-year disease-specific mortality may be associated with ADL dependency in an 80-year-old population. METHODS: In 1998, of 1,282 community-dwelling residents of Japan's Fukuoka Prefecture, 824 (64.3 %) (309 males and 515 females) participated, the remaining 458 subjects did not participate, and their deaths and causes of death were followed up for 12 years after the baseline examination. ADL dependency was determined according to the guidelines for disabled elderly from the Health, Labor, and Welfare Ministry of Japan, and ADL dependency was measured only at baseline. RESULTS: During the 12-year follow-up, 506 died, 276 did not die, and 42 were lost. Of the 506 who died, 128 died due to cardiovascular disease, 96 to respiratory tract disease, 87 to cancer, and 51 to senility. The subjects were classified into three groups as follows: ADL-1 (independent group, n = 600), ADL-2 (almost-independent group, n = 113), and ADL-3 (dependent group, n = 93).Total-cause mortality was 2.8 times higher in ADL-3 subjects, respiratory disease mortality was 4.1 times higher in ADL-3 subjects, and senility mortality was 5.7 times higher in ADL-3 subjects than in ADL-1 subjects, after adjusting for various confounding factors. There was no association between mortality due to cancer or cardiovascular disease and ADL dependency. CONCLUSIONS: We found an independent association between ADL dependency and mortality due to all causes, respiratory disease or senility, but no association with mortality due to cancer or cardiovascular disease. These findings suggest that improving ADL dependency may reduce all mortality and mortality due to respiratory disease or senility.

Oral health in patients on haemodialysis for diabetic nephropathy and chronic glomerulonephritis.

OBJECTIVE: The objective of this study was to clarify differences in oral health status between patients who needed haemodialysis (HD) owing to diabetic nephropathy (DN) and chronic glomerulonephritis (CGN). MATERIALS AND METHODS: Ninety-eight HD patients who were 50-70 years old were selected as the study subjects [DN group (29 subjects) and CGN group (69 subjects)] to compare with 106 control subjects (control group) not undergoing HD. All HD subjects underwent oral- and systemic-related examination just before HD therapy. RESULTS: The mean number of teeth present in the DN group was significantly less than in the CGN and control groups. The mean percentage of sites with bleeding on probing in the DN group was greater than in the CGN and control groups. The mean salivary flow rate in the DN and CGN groups was significantly lower compared with the control group. CONCLUSION: The patients undergoing HD for DN were found to have fewer teeth and worse periodontal health compared with those undergoing HD for CGN and with the control subjects not undergoing HD. Furthermore, the dental and periodontal health of the patients undergoing HD for CGN was comparable to that of the controls. CLINICAL RELEVANCE: For effective measures of prevention and improvement of oral health in HD patients, clinicians should be aware of the differences in the characteristics of the oral health between patients undergoing HD for DN and CGN.

Prevalence and imaging characteristics of detectable tonsilloliths on 482 pairs of consecutive CT and panoramic radiographs.

BACKGROUND: Recent studies suggest that tonsilloliths are clinically related to halitosis and tonsillar abscess. Based on our empirical knowledge, tonsilloliths are relatively commonly encountered in daily clinical practice. It has been reported that the detection rate of tonsilloliths was under 24% in previous reports, although experience suggests otherwise. The purpose of the study was to evaluate the prevalence and characteristics of tonsilloliths using computed tomography (CT). In addition, the possible causes of low detection rates on panoramic radiographs were evaluated based on comparisons between CT images and panoramic radiographs in order to elucidate the limitations of visualizing the area around the palatine tonsils on panoramic radiographs. METHODS: 482 pairs of CT images and panoramic radiographs were retrospectively assessed with respect to the presence and characteristics of tonsilloliths. In addition, the causes in cases of disagreement between the two modalities were analyzed. RESULTS: The detection rate of tonsilloliths was 46.1% using CT scans, unlike previous reports. The characteristics of tonsillolith were dot-like figures with about 300-500 Hounsfield units within the palatine tonsil under the soft palate. The most common length of tonsilloliths was about 3 or 4 mm. As the subjects aged, the detection rate increased gradually. A significant difference in the tonsillolith detection rate was found between the over and under 40-year-old groups (p < 0.0001). However, the detection rate of tonsilloliths was only 7.3% on panoramic radiographs. A significant correlation was observed between the detection rate of tonsilloliths on panoramic radiographs and CT number (Spearman r = 0.429), size, (Spearman r = 0.318), and number of tonsilloliths (Spearman r = 0.333). CONCLUSION: The present results suggest that tonsilloliths are relatively more common than previously suggested. However, panoramic radiographs detect only a small percentage of palatine tonsilloliths. The low detection rates on panoramic radiographs might be related to the degree of calcification, size, and number of tonsilloliths.

Quantitative discrimination of Aggregatibacter actinomycetemcomitans highly leukotoxic JP2 clone from non-JP2 clones in diagnosis of aggressive periodontitis.

BACKGROUND: Aggregatibacter actinomycetemcomitans is the etiological agent of periodontitis, and there is a strong association between clone JP2 and aggressive periodontitis in adolescents of African descent. The JP2 clone has an approximately 530-bp deletion (∆530) in the promoter region of the lkt/ltx gene, which encodes leukotoxin, and this clone has high leukotoxic activity. Therefore, this clone is very important in aggressive periodontitis. To diagnose this disease, culture methods and conventional PCR techniques are used. However, quantitative detection based on qPCR for the JP2 clone has not been developed due to genetic difficulties. In this study, we developed a qPCR-based quantification method specific to the JP2 clone. METHODS: Based on our analysis of the DNA sequence of the lkt/ltx gene and its flanking region, we designed a reverse primer specific for the ∆530 deletion border sequence and developed a JP2-specific PCR-based quantification method using this primer. We also analyzed the DNA sequence of the ∆530 locus and found it to be highly conserved (97-100%) among 17 non-JP2 strains. Using the ∆530 locus, we designed a qPCR primer-probe set specific to non-JP2 clones. Next, we determined the numbers of JP2 and non-JP2 clone cells in the periodontal pockets of patients with aggressive periodontitis. RESULTS: The JP2-specific primers specifically amplified the genomic DNA of the A. actinomycetemcomitans JP2 clone and did not react with other bacterial DNA, whereas the non-JP2 specific primers reacted only with A. actinomycetemcomitans non-JP2 clones. Samples from the 88 periodontal sites in the 11 patients with aggressive periodontitis were analyzed. The bacterial cell numbers in 88 periodontal sites ranged from 0 to 4.8 × 10(8) (mean 1.28 × 10(7)) for JP2 clones and from 0 to 1.6 × 10(6) for non-JP2 clones (mean 1.84 × 10(5)). There were significant differences in the JP2 cell number between a clinical attachment level (CAL) ≤6 mm and a level ≥7 mm (p < 0.01). Our new qPCR-based JP2- and non-JP2-specific quantitative detection assay is applicable to the diagnosis of aggressive periodontitis with A. actinomycetemcomitans. CONCLUSIONS: We successfully developed a quantitative and discriminative PCR-based method for the detection of A. actinomycetemcomitans JP2 and non-JP2 clones. This technique will contribute to future analyses of the quantitative relationship between this organism and aggressive periodontitis.

Salivary alpha-amylase activity and stress in Japan air self-defense force cargo pilots involved in Iraq reconstruction.

OBJECTIVES: This study aimed to verify whether salivary α-amylase enzyme activity (Amy) is useful as a biomarker of stress in pilots working in a stressful environment. METHODS: The subjects in this study were nine Japan air self-defense force pilots who participated in Iraq reconstruction support activity in Kuwait. Amy was measured using a portable salivary amylase monitor at preflight, postflight, and on stand-by day. In addition, the state-trait anxiety inventory was administered with state scores (STAI-S) compared to Amy levels. RESULTS: There were greater differences in Amy levels at baseline compared to STAI-S scores between subjects on the stand-by day. Amy levels at preflight tended to increase compared to those on stand-by day as did STAI-S. The change in Amy level at postflight varied among the pilots. The Amy levels of four subjects at postflight were elevated compared to levels at preflight, while the STAI-S scores for all pilots at postflight were lower than at preflight. CONCLUSIONS: This study suggests that the Amy level of pilots can reflect subtle individual differences in response to the psychological and physiological stress of a flight task. Thus, monitoring Amy level may be useful for stress evaluation of pilots working in a stressful environment, providing data that might be used as an impetus for addressing stress management for this population.

Wear of Polymer-Infiltrated Ceramic Network Materials against Enamel.

Polymer-infiltrated ceramic network materials (PICNs) have high mechanical compatibility with human enamel. However, the wear properties of PICN against natural human enamel have not yet been clarified. We investigated the in vitro two-body wear behaviors of PICNs and an enamel antagonist. Two PICNs were used: Experimental PICN (EXP) prepared via the infiltration of methacrylate-based resin into the porous silica ceramic network and commercial Vita Enamic (ENA). Two commercial dental ceramics, lithium disilicate glass (LDS) and zirconia (ZIR), were also characterized, and their wear performance was compared to PICNs. The samples were subjected to Vickers hardness tests and two-body wear tests that involve the samples being cyclically impacted by enamel antagonists underwater at 37 °C. The results reveal that the Vickers hardness of EXP (301 ± 36) was closest to that of enamel (317 ± 17). The volumetric wear losses of EXP and ENA were similar to those of LDS but higher than that of zirconia. The volumetric wear loss of the enamel antagonist impacted against EXP was moderate among the examined samples. These results suggest that EXP has wear behavior similar to that of enamel. Therefore, PICNs are mechanically comparable to enamel in terms of hardness and wear and are excellent tooth-restoration materials.

Relationship between Dynamics of TNF-α and Its Soluble Receptors in Saliva and Periodontal Health State.

Soluble tumor necrosis factor receptors 1 and 2 (sTNF-R1 and sTNF-R2) are reported to protect against excessive TNF-α, a primary mediator of systemic responses to infection. This study aimed to investigate the levels of TNF-α, sTNF-R1, and sTNF-R2 in saliva and to verify whether their dynamics are associated with periodontal health. The study population comprised 28 adult patients. Probing pocket depth, clinical attachment level, and bleeding on probing were assessed, and periodontal inflamed surface area (PISA) was calculated. Stimulated saliva was collected before the oral examinations. The levels of TNF-α, sTNF-R1, sTNF-R2, and total protein (TP) in saliva samples were determined. There were significant positive correlations between TNF-α, sTNF-R1, and sTNF-R2 to TP (/TP) in stimulated saliva. Moreover, there were significant positive correlations between PISA and sTNF-R2/TP. Stepwise multiple regression analysis revealed that PISA was significantly associated with sTNF-R2/TP in saliva; however, TNF-α/TP was not significantly associated with PISA. In conclusion, this study demonstrates that significant relationships exist between the salivary levels of TNF-α and sTNF-R1, and that salivary sTNF-R2 is associated with the expansion of inflamed periodontal tissue.

Castable polymer-infiltrated ceramic network composite for training model tooth with compatible machinability to human enamel.

This study aimed to develop a novel polymer-infiltrated ceramic network (PICN) composite fabricated via a slip-casting method for a dental training model tooth with machinability compatible to human enamel. A PICN model tooth comprised of silica/acrylic-resin was fabricated via the slip-casting method. A commercial resin-based model tooth and human enamel were used as the control sample. The samples were evaluated based on Vickers hardness, inorganic contents, density, and machinability. The machinability was characterized by a grinding amount obtained from the grinding test using a device equipped with a dental micromotor handpiece with a diamond bur. The properties of the PICN model tooth yielded a silica content of 84.7% and a density of 1.99 g/cm3, and its Vickers hardness (312) was comparable with that of enamel (348). The grinding amount was comparable with that of enamel. The castable PICN model tooth was compatible to enamel in terms of hardness and machinability.

Effect of COVID-19 on dental telemedicine in Japan.

BACKGROUND/PURPOSE: In Japan, medical and dental care is provided by the universal health insurance system. The Ministry of Health, Labour, and Welfare (MHLW) in Japan sets the rules for health care services provided by health insurance. The MHLW issued a notice in 2020 permitting telemedicine and dental telemedicine for the first visit and for follow-up visits to prevent the spread of COVID-19 infection. We conducted this study to clarify the status of dental telemedicine during 2020. MATERIALS AND METHODS: We used data from lists obtained on the MHLW website in the analysis. We investigated the number of dental institutions conducing dental telemedicine for the first visit and for follow-up visits by prefecture. RESULTS: In each prefecture, fewer dental institutions conducted telemedicine for the first visit than for follow-up visits. Regions with large metropolitan areas had higher numbers of dental institutions conducting dental telemedicine for the first visit and follow-up visits. Private dental clinics provided the largest proportion of dental telemedicine for the first visit, and general hospitals provided the largest proportion for follow-up visits. CONCLUSION: Our study findings indicated that many dental institutions in Japan made efforts to provide dental services via dental telemedicine using the telephone or online with video to help prevent the spread of COVID-19 infection. Dental telemedicine can help patients to access dental services and dental care, thereby expanding the potential of dental telemedicine in Japan.

The Alteration of Brain Function by the Improvement of Periodontal Tissues and Occlusal State.

Objective: In this study, we have introduced a case in which the effective blood oxygenation level-dependent signal on functional magnetic resonance imaging (fMRI) was altered by the improvement of periodontal tissue and occlusal function in a patient with periodontitis Stage II Grade B. Material and Methods. A 61-year-old female patient requiring periodontal treatment was diagnosed as having periodontitis Stage II Grade B via clinical and radiographic examinations. Her past medical history included type 2 diabetes, hypertension, and hyperlipidemia. Following the patient's informed written consent, the periodontal initial treatment provided to the patient included tooth brushing instruction and scaling and root planing; however, occlusal adjustment was not performed at this stage. Occlusal force and fMRI results were also evaluated at the initial and reevaluation examinations. Results: After the periodontal initial treatment had been performed, it was noted that the patient's periodontal tissue and occlusal force had improved. It was also evident from fMRI that cerebral blood flow had been activated in the insula, primary motor cortex, and premotor cortex. Conclusion: This result suggested that the periodontal ligament had recovered and the periodontal ligament neuron had been further subjected to clenching in the insula so that the muscle spindle sensation impacted the motor cortex.

Enumeration of viable Enterococcus faecalis, a predominant apical periodontitis pathogen, using propidium monoazide and quantitative real-time polymerase chain reaction.

To discriminate between viable and non-viable Enterococcus faecalis, the predominant pathogen in apical periodontitis, a real-time PCR method combined with propidium monoazide (PMA) was developed and evaluated. PMA had no antimicrobial effect on E. faecalis cells and permitted enumeration of both viable and non-viable cells. Therefore, E. faecalis cells from the root canals of nine patients with apical periodontitis were analyzed to evaluate the diagnostic usefulness of this approach. Viable and non-viable E. faecalis cells were successfully discriminated in these clinical specimens. A real-time PCR assay combined with PMA will contribute to the precise diagnosis of apical periodontitis.

Relationship between tooth loss and mortality in 80-year-old Japanese community-dwelling subjects.

BACKGROUND: Findings from several studies suggest associations between tooth loss and health outcomes, including malnutrition, poor quality of life, and mortality, in older individuals. However, limited information is available regarding whether those associations remain true in very elderly subjects after adequately considering confounding factors such as sex and smoking status. Herein, we determined whether the number of teeth in 80-year-old subjects is an independent predictor of mortality. METHODS: We initially contacted 1282 80-year-old community-dwelling individuals born in 1917, of whom 697 responded and participated in a baseline study, with follow-up examinations conducted 4 and 5.5 years later. Data from interviews and medical and oral examinations were obtained, and oral health was determined according to the number of teeth remaining in the oral cavity. RESULTS: A total of 108 and 157 subjects died in 4 years and 5.5 years, respectively, after the baseline study. Tooth loss was significantly associated with mortality at age 85.5, but not at age 84, after adjusting for potential confounders. When the analysis was stratified by sex, we found a stronger association in females in follow-up examinations conducted at both 4- and 5.5 years. On the other hand, the effect of tooth loss on mortality was not significantly different between smokers and non-smokers. CONCLUSION: Tooth loss is a significant predictor of mortality independent of health factors, socio-economic status, and lifestyle in octogenarians, with a stronger association in females.

IgA level is associated with risk for mortality in an eighty-year-old population.

BACKGROUND: Immunoglobulin levels are elevated in the older people. However, it is unknown whether these levels are related to mortality. OBJECT: To evaluate the association between immunoglobulin levels and mortality. METHODS: The study population included 697 individuals (277 males and 420 females) of 1,282 eighty-year-old individuals residing in the Fukuoka prefecture, Japan. The participants were followed for 4 years after the baseline examination. RESULTS: The hyper-IgA group, defined as a serum IgA level >400 mg/dl, had high mortality using Kaplan-Meier analysis (log rank, p=0.037). Multivariate Cox regression analyses revealed a high risk of mortality (hazard rate=1.233, 95% confidence interval 1.109-1.491, p=0.031) after adjusting for covariates. The high risk of mortality in the hyper-IgA group was significant in males, but not in females. Moreover, Kaplan-Meier analysis revealed that IgA was related to cancer mortality in males (log rank, p=0.031), but not to pneumonia or cardiovascular disease. IgM and IgG levels were not related to high risk of mortality. CONCLUSION: Serum IgA levels appear to be a predictor of mortality, especially cancer mortality in males.