Oral malodor was measured using a portable sulphide monitor in 2,672 individuals aged 18 to 64 years. In addition, dental (DMFT) and periodontal conditions (CPITN and attachment loss), dental plaque, and tongue coating status were assessed. Before clinical examination, subjects were interviewed about their oral health habits, smoking habits, and medical history. Data on volatile sulphur compounds (VSC) were analyzed by gender, age group, and time of measurement. There were no significant differences observed in the VSC between males and females in any age group. In each age group, the measured values of oral malodor were highest in the late morning group (58.6 ppb in average), followed by the late afternoon group (52.1 ppb), while lowest values were shown in the early afternoon group (39.4 ppb). Significant correlation was observed only between the VSC value and periodontal conditions and tongue coating status. The results also suggest that oral malodor might be caused mainly by tongue coating in the younger generation and by periodontal diseases together with tongue coating in older cohorts in the general population. Age was not a risk factor for increasing VSC.
The loss of teeth is known to influence the mastication of foods and nutritional status. Therefore, we hypothesize that poor dentition status can impair the systemic health of the aged. To clarify the influence of dentition status on deterioration in physical ability, mental impairment, and mortality, we conducted a six-year prospective cohort study of the institutionalized elderly living in 29 of the 30 institutions for the elderly in Kitakyushu, Japan. Bivariate analysis revealed that worse dentition status at baseline led to significantly worse physical and mental impairment, and higher mortality. In a multiple logistic regression analysis, the physical ability of edentulous subjects without dentures significantly deteriorated compared with that of dentate subjects with 20 or more teeth. The six-year mortality rate of the edentulous subjects without dentures was significantly higher than that of the subjects with 20 or more teeth. Poorer dentition status, especially edentulousness without dentures, may therefore be related to deterioration in the systemic health of the aged.
Although poor oral health influences the occurrence of pulmonary infection in elderly people, it is unclear how the degree of oral health is linked to mortality from pulmonary infection. Therefore, we evaluated the relationship between oral health and four-year mortality from pneumonia in an elderly Japanese population. The study population consisted of 697 (277 males, 420 females) of the 1282 individuals who were 80 years old in 1997. Data on oral and systemic health were obtained by means of questionnaires, physical examinations, and laboratory blood tests. One hundred eight of the study persons died between 1998 and 2002. Of these, 22 deaths were due to pneumonia. The adjusted mortality due to pneumonia was 3.9 times higher in persons with 10 or more teeth with a probing depth exceeding 4 mm (periodontal pocket) than in those without periodontal pockets. Therefore, the increase in teeth with periodontal pockets in the elderly may be associated with increased mortality from pneumonia.
Streptococcus mutans is implicated as a major etiological agent in human dental caries, and one of the important virulence properties of this organism is its ability to form biofilms (dental plaque) on tooth surfaces. We examined the role of autoinducer-2 (AI-2) on S. mutans biofilm formation by constructing a GS-5 luxS-null mutant. Biofilm formation by the luxS mutant in 0.5% sucrose defined medium was found to be markedly attenuated compared to the wild type. Scanning electron microscopy also revealed that biofilms of the luxS mutant formed larger clumps in sucrose medium compared to the parental strain. Therefore, the expression of glucosyltransferase genes was examined and the gtfB and gtfC genes, but not the gtfD gene, in the luxS mutant were upregulated in the mid-log growth phase. Furthermore, we developed a novel two-compartment system to monitor AI-2 production by oral streptococci and periodontopathic bacteria. The biofilm defect of the luxS mutant was complemented by strains of S. gordonii, S. sobrinus, and S. anginosus; however, it was not complemented by S. oralis, S. salivarius, or S. sanguinis. Biofilm formation by the luxS mutant was also complemented by Porphyromonas gingivalis 381 and Actinobacillus actinomycetemcomitans Y4 but not by a P. gingivalis luxS mutant. These results suggest that the regulation of the glucosyltransferase genes required for sucrosedependent biofilm formation is regulated by AI-2. Furthermore, these results provide further confirmation of previous proposals that quorum sensing via AI-2 may play a significant role in oral biofilm formation.Quorum sensing (QS) is a process whereby bacteria communicate with one another by means of the secretion of chemical signal molecules called autoinducers (AIs) (3,4,35,38). In the bioluminescent gram-negative marine bacterium Vibrio harveyi, two distinct AIs, AI-1 (6, 9) and AI-2, regulate light emission (36). LuxS is an enzyme involved in the catabolism of S-adenosylmethionine and converts ribose homocysteine into homocysteine and 4,5-dihydroxy-2,3-pentanedione, the precursor of 46,51). This system has been referred to as an interspecies quorum system and may operate as a universal quorum system for many bacteria possessing the characteristic luxS gene (5). The luxS gene is highly conserved across a diverse range of gram-negative and gram-positive bacterial species, and AI-2 is produced by many of these species. QS enables a population of bacteria collectively to regulate gene expression including expression of virulence factors (21, 39), competence for genetic transformation (1, 28, 37), conjugal DNA transfer (20,52,56), and the production of antibiotics and secondary metabolites (31, 49), as well as biofilm formation (13). However, more recent investigations have also indicated that AI-2 production is regulated at the level of LuxS substrate availability and not at the level of luxS expression. Consequently, AI-2-dependent signaling can also reflect the metabolic state of the cell and not necessarily cell density (7).Biofilms are se...
There is a relationship between perceived chewing ability (number of foods considered chewable) and physical fitness in this 80-year-old population. Chewing ability may be an independent predictor of physical fitness, thus preventative dental care aimed at preserving chewing ability may be able to enhance activities of daily life and quality of life in very elderly individuals.
The periodontal conditions of 2424 pregnant and 1565 non-pregnant women were assessed according to the community periodontal index of treatment needs (CPITN). The aim of this survey was to obtain information which is necessary for the planning of preventive programs of periodontal disease for pregnant women. 95% of the pregnant women and 96% of the non-pregnant women had some signs of periodontal disease. The % of pregnant women having 4 or 5 mm pockets was significantly higher than that of non-pregnant women, increased with the month of pregnancy, reached a maximum of 31% in the 8-month group, but decreased to the control level in the 9-month group. These changes were interpreted to suggest that the increase of pocket depth during pregnancy was caused by gingival enlargement rather than by periodontal destruction. The results show that pregnant women had a healthier periodontal condition when compared with non-pregnant women, i.e., the number of sextants with healthy periodontal tissues was higher, the % of people having deep pockets (6 mm or deeper) was lower, and the need for prophylaxis was lower in pregnant than in non-pregnant women. These findings suggest that a special program of periodontal disease prevention for pregnant women is not necessary.
A mutant defective in acidurcity, GS5Tn1, was constructed following mutagenesis of Streptococcus mutans GS5 with the conjugative transposon Tn916. The mutant grew poorly at acidic pH levels and was sensitive to high osmolarity and elevated temperatures. These properties resulted from a single insertion of Tn916 into the GS5 chromosome, and the DNA fragment harboring the transposon was isolated in the cosmid vector, charomid 9-20. Spontaneous excision of Tn916 from the cosmid revealed that Tn916 inserted into a 8.6-kb EcoRI fragment. On the basis ofthe restriction analyses ofinsert fragments, it was found that Tn916 inserted into a 0.9-kb EcoRI-XbaI fragment. Nucleotide sequence analysis of this frnaent indicated the presence of two open reading frames, ORF1 and ORF2. By using a marker rescue strategy, a 6.0-kb Hindm fragment including the target site for Tn916 insertion and the 5' end of ORF1 was isolated and sequenced. The deduced amino acid sequences of ORF1 and ORF2 showed significant homology with the diacylgycerol kinase and Era proteins, respectively, from Escherichia coli. Nucleotide sequence analysis of the Tn916 insertion junction region in the GSSTn1 chromosome revealed that the transposon inserted near the 3' terminus of ORF1. Restoration of ORF1 to its orignal sequence in mutant GS5Tn1 was carried out following transformation with integration vector pVA891 containing an intact ORF1. The resultant transformant showed wild-type levels of aciduricity as well as resistance to elevated temperatures and high osmolarity. These results suggest that the S. mutans homolog of diacylglycerol kinase is important for adaptation of the organism to several environmental stress signals.
The findings of the present study indicated that 85-year-old participants with > or = 20 teeth had better subjective physical health than those with < or = 19 teeth.
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