益生菌防治龋病的研究进展

随着人们生活水平日益提高,口腔健康越来越受到关注。近年来,益生菌对口腔菌群和宿主健康的调节作用已成为广泛研究的话题。已有证据表明,益生菌可以竞争性地抑制口腔中致病细菌的黏附和定植,分泌抗菌物质以减少病原菌。本文综述了相关益生菌对变形链球菌这一公认的龋齿病原菌的作用,包括:(1)生物表面活性剂、细菌素、胞外多糖等益生菌代谢产物对变形链球菌牙菌生物膜的抑制作用;(2)刺激宿主免疫反应,调节口腔菌群组成;(3)下调或阻断变形链球菌细胞中与黏附在牙齿表面形成生物膜相关的基因表达。     

Caries incidence in patients with dementia

One in ten persons over the age of 65 and as many as half the population aged 85 and over have Alzbeimer's disease. Review of the literature reveals substantial decrements in oral health in persons with dementia as measured by denture hygiene, coronal decayed, missing and filled teeth, filled teeth (cervical), percentage of the population with caries. Oral Hygiene Index-simplified, and of sites with plaque, gingival bleeding and calculus. A study of caries incidence is described in 23 male veterans with moderate and advanced dementia of the Alzheimer's type, using a comparison group of male veterans from the Department of Veterans Affairs Dental Longitudinal Study, matching 2 :1 for age, number of teeth and education. Baseline findings indicate significant differences in the numbers of coronal surfaces with decay, root decayed and/or filled teeth and root decayed and/or filled surfaces. Mean annual increments of coronal caries in the dementia group were 2.29±4.29 per 100 surfaces at risk, over twice that in the comparison group (0.88±1.14). For root caries, mean annual increments in the dementia group were 2.38±5.57 per 100 available surfaces, versus 0.31± 0.69 in the comparison group. Despite these large mean differences, the marked variability in these small samples statistical significance in caries increments between the two groups. The article concludes by suggesting some potential modifications to clinical trials of caries preventive agents and some overall research issues in populations with dementia.     

A comparison of four home-care fluoride programs on the caries incidence in the elderly

Objective : To estimate the caries preventive effect of 4 fluoride programs over 2 years in the elderly. Setting : The Public Dental Clinics of Balsta and Knivsta and the Faculty of Odontology in Göteborg, Sweden Subjects : One hundred and sixty-four individuals, aged 60 years and older (mean age 71.5 years) who were considered to be at risk from caries. Design : The participants were randomly assigned either to: 1) rinse twice a day with a 0.05% NaF solution (n=49; rinsing group), 2) suck twice a day on a 1.66 mg NaF tablet (n=51; tablet group). 3) brush their teeth three times a day using a toothpaste slurry rinsing technique (n=32; slurry group), or 4) brush their teeth in their usual manner (n=32; control group). The participants in all 4 groups used a fluoride toothpaste (containing 0.32% NaF) at least twice daily. Results : No new carious lesions were found in 67% of the participants in the rinsing, 43% in the tablet, 25% in the slurry and 16% in the control group over the 2 years. The mean (± SD) 2-year caries increment was 0.8±1.4, 1.4±1.7, 1.9±1.9 and 2.3±2.1 DFS in the rinsing, tablet, slurry and control groups, respectively; it was significantly lower in the rinsing than in the control group (p<0.01). A lower incidence of DFS was also found in the tablet group than in the slurry group, but only for the lingual surfaces (p<0.05). Conclusion : The type of fluoride program may be of importance in the reduction of new caries lesions in an older population.     

细菌生物膜与龋齿相关性的研究进展

牙菌斑是由多种微生物在牙面上沉积,有机基质互相集聚、交联而形成的生物膜结构,生物膜中微生物相互依存、相互竞争,构成了复杂的微生态关系。牙菌斑生物膜的形成是导致龋齿重要过程。本文综述了细菌生物膜与龋齿发生的关系,以期为龋齿的预防与治疗提供新的思路。     

Issues in the epidemiological investigation of dry mouth

Despite decades of research, much remains unanswered about the epidemiology of dry mouth. This review aims to provide an overview of the condition's epidemiology and the issues to consider when planning an epidemiological study of dry mouth. The latter can be broadly grouped into: study design; sampling and statistical power considerations; the measurement of dry mouth; and the selection, nature and measurement of relevant exposure measures, including medications and potential confounding variables. Each of these is discussed, in order to provide guidance for prospective researchers based on experience with past research. Finally, an agenda for further epidemiological research into dry mouth is proposed.     

Partial dentures as an independent indicator of root caries risk in a group of older adults.

Objectives: To estimate the independent association between the wearing of removable partial dentures (RPD) and the presence of root caries in a population of older adults. Design: Multivariate logistic regression modeling of root caries prevalence using different measures of root caries as dependent variables. The model included measures of disease history as indicators of historical risk. Setting: Data collected in the field from three areas of England. Subjects: Random sample of adults aged 60 years and over, drawn from lists of patients registered with general medical practitioners. Intervension: Field measurements of a range of oral health variables including oral disease, disease history, oral status and various social and demographic measures. Main outcome measures: The presence of root caries, unsound and sound root restorations. Results: Of the five different models of root caries prevalence which were used, RPDs featured as an independent risk indicator for root surface cades in the three which were related to the presence of untreated disease. The odds ratios for the contribution made by RPDs were all over 1.6, and when considered alone was in excess of 2 in one model. These models were generally well fitting. RPDs did not feature as a risk indicator in the two models which related only to the presence of root surface restorations. Conclusions: In this study, where RPDs were present, the odds of untreated disease being present increased substantially     

Log-linear analysis of dental caries occurrence in four skeletal series.

Four skeletal series (Corinth, Greece; Gran Quivira, New Mexico; Semna South, Sudanese Nubia, and a large group from scattered sites in England) were coded for sex, jaw, tooth group, dental attrition, dental caries, site and time period. Through thec concepts of a basal level of caries and a cariosity gradient, a single model was found which best described the occurrence of this disease in these samples. All factors were found to contribute significantly to the model. Within the possible subsamples the general characteristics are that the profiles of males, of the mandibulae and of those with light attrition are more likely to have lower overall dental caries levels and to be relatively more carious in the back of the mouth than the front when compared to the pooled sample of all teeth and caries. The opposite is also found to be generally true; the teeth of females, maxillae and heavy attrition are associated with more caries, especially toward the front of the mouth. These results imply that samples appearing otherwise homogeneous display much variation. They also reveal distinct regularities in the reactions of diverse human groups to dental caries.     

The effect of Salinum on the symptoms of dry mouth: a pilot study

The effect of a new saliva substitute. Salinum®, was tested in 37 patients with severe symptoms of reduced salivation. The majority of the patients had suffered from hyposalivation and dry mouth for more than 8 years. The saliva substitute consisted of a water soluble extract of linseed. The physical properties of this extract are similar to those of the glycoproteins of the salivary secretions. The patients used the saliva substitute for a seven days period. Prior to the use of the extract the patients reported that the most severe symptoms of decreased salivation were a feeling of dryness in the mouth and burning sensations in the tongue, pharynx and oesophagus, The majority of the patients reported that the use of Salinum reduced the symptoms of hyposalivation. Great variation in effect occurred from patient to patient. Generally the patients with the most severe symptoms experienced the greatest relief of the symptoms when they used Salinum. Although of short duration the results of this pilot study indicate that an extract of linseeds may compensate for some aspects of the consequences of reduced salivation. Further studies are needed to elucidate the feasibility of the extract as saliva replacement.     

Caries incidence and increments in community-living older adults with and without dementia

Objectives: The Oral Health of Older Adults with Dementia was instigated in the late 1990s to quantify and compare coronal and root caries incidence and increments in community‐living older Australians with and without dementia. Methods: A longitudinal design was used to conduct dental inspections at baseline and one‐year, for two groups of randomly selected community‐living older adults ‐ one group of 116 people with dementia and a comparison group of 116 people without dementia. Results: At one‐year there were 103 dementia and 113(112 dentate) non‐dementia participants. Coronal and root surface caries incidence was higher for dementia participants (p<0.05). Dementia participants had higher coronal and root caries adjusted caries increments (ADJCI) (p<0.01). Both coronal and root ADJCI were evident in half of dementia participants, compared with one‐quarter of non‐dementia participants. Dementia participants with higher coronal ADJCI were those who had visited the dentist since baseline, who were taking neuroleptics with high anticholinergic adverse effects, and whose carer had high carer burden score (p<0.01). Dementia participants with higher root ADJCI were those needing assistance with oral hygiene care and whose carers had difficulties with oral hygiene care (p<0.05). Baseline characteristics predictive in linear regression for: (1) coronal caries increments among all participants were ‐ dementia participants, those with cognitive testing scores indicative of moderate‐severe dementia, those with private health insurance; (2) root caries increments among all participants were ‐ dementia participants, and those who had 1 decayed/filled root surface at baseline. Among dementia participants, being male was the baseline characteristic predictive in logistic regression for coronal caries increments, and having 1 decayed coronal surface was the baseline characteristic predictive for root caries increments. Conclusions: Coronal and root caries incidence and increments were significantly higher in the community‐living older adults with dementia over the one‐year follow‐up period. Dementia participants had high levels of coronal and root caries increments; characteristics related to high caries increments included sex (males), dementia severity (moderate‐severe), high carer burden, oral hygiene care difficulties, use of neuroleptic medication (with high anticholinergic adverse effects) and previous experience of caries.     

Association of genetic variants in enamel-formation genes with dental caries: A meta- and gene-cluster analysis

Previous studies have reported the association between multiple genetic variants in the enamel-formation genes and the risk of dental caries with inconsistent results. We performed a systematic literature search of the PubMed, Cochrane Library, HuGE and Google Scholar databases for studies published before March 21, 2020 and conducted meta-, gene-based and gene-cluster analysis on the association between genetic variants in the enamel-formation genes and the risk of dental caries. We identified 21 relevant publications including a total of 24 studies for analysis. The genetic variant rs17878486 in AMELX was significantly associated with dental caries risk (OR = 1.40, 95% CI: 1.02–1.93, P = 0.037). We found no significant association between the risk of dental caries with rs12640848 in ENAM (OR = 1.15, 95% CI: 0.88–1.52, P = 0.310), rs1784418 in MMP20 (OR = 1.07, 95% CI: 0.76–1.49, P = 0.702) and rs3796704 in ENAM (OR = 1.06, 95% CI: 0.96–1.17, P = 0.228). Gene-based analysis indicated that multiple genetic variants in AMELX showed joint association with the risk of dental caries (6 variants; P < 10⁻⁵), so did genetic variants in MMP13 (3 variants; P = 0.004), MMP2 (3 variants; P < 10⁻⁵), MMP20 (2 variants; P < 10⁻⁵) and MMP3 (2 variants; P < 10⁻⁵). The gene-cluster analysis indicated a significant association between the genetic variants in this enamel-formation gene cluster and the risk of dental caries (P < 10⁻⁵). The present meta-analysis revealed that genetic variant rs17878486 in AMELX was associated with dental caries, and multiple genetic variants in the enamel-formation genes jointly contributed to the risk of dental caries, supporting the role of genetic variants in the enamel-formation genes in the etiology of dental caries.     

The role of lead and cadmium in deciduous teeth and saliva on dental caries in children residing in Tehran,Iran

BackgroundLead (Pb) and Cadmium (Cd) are important environmental contaminants. There is no biological monitoring of exposure to these heavy metals and their potential effect on dental caries in children in Tehran, Iran, a polluted megacity. Therefore, the present study investigated the potential association between Pb and Cd levels in primary teeth and saliva and dental caries.MethodsIn a cross-sectional design, 211 children aged 6–11 years referred to Tehran University of Medical Sciences, School of Dentistry and residing in Tehran were examined. Pb and Cd levels of exfoliated primary teeth and stimulated saliva were determined by atomic absorption spectrophotometry (AAS). Dental caries prevalence was evaluated according to WHO criteria. Socioeconomic status, oral hygiene behavior, snacking frequency and salivary pH data were acquired as confounding factors. Frequency and percentages were reported for categorical variables, mean and standard deviation (SD) for continuous variables, and geometric mean for skewed continuous variables. A simple linear regression and Pearson correlation tests were used for statistical analyses. P-values < 0.05 were considered as significant.ResultThe mean (95 % confidence interval) Pb and Cd levels in teeth were 213.26 ppb (164.29–274.84) and 23.75 ppb (20.86–27.05), respectively. The mean Pb and Cd levels in saliva were 11.83 ppb (10.71–13.06) and 3.18 ppb (2.69–3.75), respectively. Furthermore, Pb and Cd in primary teeth and saliva were not associated (p > 0.05) with socioeconomic status, oral hygiene behavior and snacking frequencyConclusionThis study showed no association between Pb and Cd concentrations in primary teeth and in saliva with dental caries prevalence.     

Usefulness of new wetness tester for diagnosis of dry mouth in disabled patients

Objectives: The condition of dry mouth is an influential factor in the incidence of caries, periodontal disease, fungal infections, masticatory dysfunctions and denture function. Bedridden elderly and disabled persons often suffer from oral dryness and the aim of this study was to evaluate the usefulness of measuring the amount of moisture in the oral mucosa for clinical diagnosis of dry mouth in this group. Subjects and methods: The subjects were 20 elderly bedridden individuals, age range 65–89 years old, living in a nursing home and six healthy laboratory researchers, aged 20–46 years old, used as controls. Tongue dorsum moisture measurements were performed using a newly developed wetness tester (L‐SALIVO^®), in which the wet portion was measured after 10 s. Further, clinical diagnosis of dry mouth was carried out using a clinical classification scale of the tongue mucosa (grade range, 0–3). Results: It was possible to measure tongue dorsum moisture in all subjects with the wetness tester. The average moisture value was 0.1 ± 0.2 mm in elderly subjects with a dry mouth grade of 2 (n = 8) or 3 (n = 12), while the average moisture value in the control subjects was 3.67 ± 1.75 mm with a dry mouth grade of 0 (n = 4) or 1 (n = 2). Tester values and clinical classification showed a positive co‐relationship (r = 0.31, p < 0.05). Conclusions: Our results show that this new tester could be useful for evaluating oral dryness and diagnosing dry mouth.     

Factors which are associated with dental decay in the older individual

Objectives: To improve reliability of salivary bacterial cultures as a surrogate for plaque levels of cariogenic bacterial species by reporting the salivary CFUs of these organisms as a function of the number of teeth. Design: Cross-sectional collection of data in a convenience sample of adults over 60 years of age. Setting: Hospital Dental clinic, University bacteriology laboratory. Subjects: 523 older dentate subjects, average age 70, including 412 subjects who were in an independent living status and 111 in a dependent-living situation. Main outcome measures : Subjects were examined for decay and the presence of salivary factors including the levels of S. mutans, lactobacilli, yeast and other bacteria. The salivary levels of the bacteria were adjusted for the number of teeth in the mouth, and the resultant values were entered into multivariable logistic regression models along with clinical and other salivary parameters. Results: Mutans streptococci levels reported as CFUs/ml saliva per tooth were significantly associated with coronal surface decay, and lactobacilli, reported in a similar way, were significantly associated with root surface decay. Salivary levels of yeasts, which had previously been associated with decay in this population, were no longer significant using this construct. Conclusions : This construct of reporting salivary bacteriological data as a function of tooth number and per ml saliva could improve the reliability of bacteriological data obtained in epidemiological studies investigating the role of bacteria in dental decay in the elderly.     

Impact of dry mouth conditions on oral health-related quality of life in older people

Objective: The aim of the present study was to evaluate the impact of dry mouth conditions on oral health‐related quality of life in frail old people, residents at community care centers. Further, reliability and validity of a visual analogue scale (VAS) for dry mouth symptoms were determined within the study cohort. Background: In old people functional, social and psychological impacts of oral conditions are associated with an overall sense of well being and general health. Subjective dry mouth and reduced saliva flow are common disorders in old people caused by disease and medication. Thus, dry mouth conditions may be determinants for compromised oral health‐related quality of life in old people. Method: In total, 50 old people living at service homes for the old people were asked to answer questionnaires on subjective dry mouth (VAS) and Oral Health Impact Profile (OHIP14) for oral health‐related quality of life. Saliva flow was estimated by absorbing saliva into a pre‐weighed cotton roll. Results: The final study cohort comprised 41 old people (aged 83–91 years). Significant associations were identified between both objective and subjective dry mouth and overall or specific aspects of oral health‐related quality of life. Conclusion: Dry mouth (objective and subjective) is significantly associated with oral health‐related quality of life strengthening the value of monitoring dry mouth conditions in the care of frail old people.     

The efficacy of three formulations of Lippia sidoides Cham. essential oil in the reduction of salivary Streptococcus mutans in children with caries: A randomized,double-blind,controlled study

Essential oils of many plants have been previously tested in the treatment of oral diseases and other infections. This study was a randomized, double-blind, in parallel with an active control study, which aimed to evaluate the efficacy of three formulations of the Lippia sidoides Cham. essential oil (LSO) in the reduction of salivary Streptococcus mutans in children with caries. 81 volunteers, aged 6–12 years, both genders, with caries, were recruited to participate in this study, and randomly assigned to either one of five different groups. Each group received topical treatment with either 1.4% LSO toothpaste, 1.4% LSO gel, 0.8% LSO mouthwash, 1% chlorhexidine gel, or 0.12% chlorhexidine mouthwash. A 5-ml volume of each gel was placed inside disposable trays, and applied for 1 min, every 24 h, for 5 consecutive days. The mouthwash groups used 5-ml volume of a mouthwash inside disposable syringes. In the toothpaste group, children brushed their teeth for 1 min, once a day for 5 days. Saliva was collected before and after treatment. MS colonies were counted, isolated and confirmed through biochemical tests. Differences in MS levels measured in different days within the same treatment group was only verified with LSO toothpaste, chlorhexidine gel and chlorhexidine mouthwash. Comparison between groups of LSO mouthwash, toothpaste and gel showed that the toothpaste group expressed significantly lower MS levels than the mouthwash and gel groups at day-30. Chlorhexidine significantly reduced MS levels after 5 days of treatment, but these levels returned to baseline in other periods of the study. LSO toothpaste reduced MS levels after 5 days of treatment, and MS levels remained low and did not return to baseline during subsequent analysis. Hence, LSO toothpaste demonstrated the most long-lasting MS reduction in saliva, whereas other LSO formulations did not effectively reduce MS levels in children with dental caries.     

Antimicrobial and anti-biofilm effect of Bac8c on major bacteria associated with dental caries and Streptococcus mutans biofilms

Dental caries is a common oral bacterial infectious disease. Its prevention and treatment requires control of the causative pathogens within dental plaque, especially Streptococcus mutans (S. mutans). Antimicrobial peptides (AMPs), one of the promising substitutes for conventional antibiotics, have been widely tested and used for controlling bacterial infections. The present study focuses on evaluating the potential of the novel AMPs cyclic bactenecin and its derivatives against bacteria associated with dental caries. The results indicate that Bac8c displayed highest activity against the bacteria tested, whereas both cyclic and linear bactenecin had weak antimicrobial activity. The cytotoxicity assay showed that Bac8c did not cause detectable toxicity at concentrations of 32–128 μg/ml for 5 min or 32–64 μg/ml for 60 min. S. mutans and Lactobacillus fermenti treated with Bac8c showed variable effects on bacterial structure via scanning electron microscopy and transmission electron microscopy. There appeared to be a large amount of extracellular debris and obvious holes on the cell surface, as well as loss of cell wall and nucleoid condensation. The BioFlux system was employed to generate S. mutans biofilms under a controlled flow, which more closely resemble the formation process of natural biofilms. Bac8c remarkably reduced the viability of cells in biofilms formed in the BioFlux system. This phenomenon was further analyzed and verified by real-time PCR results of a significant suppression of the genes involved in S. mutans biofilm formation. Taken together, this study suggests that Bac8c has a potential clinical application in preventing and treating dental caries.     

Ten-year cross-sectional and incidence study of coronal and root caries and some related factors in elderly Swedish individuals

Objective: The 10‐year incidence of dental caries was related to some associated factors in a random sample of 65, 75 and 85‐year‐old inhabitants of Gothenburg. Subjects: Of the 208 persons examined at baseline, 102 (49%) participated in the follow‐up examination; 56, 37 and nine, respectively, in the different age groups. For the purpose of time‐trend comparisons, a new random sample of 98 individuals aged 55 years was examined. Results: Ninety‐five per cent of the participants had developed one or more carious lesions during the 10‐year period and the incidence of coronal and root caries increased with age. In the 65‐year‐olds, 9% of the root surfaces had decayed during the period, compared with 25% in the 85‐year‐olds. Secondary caries predominated over primary caries and prosthetic crowns accounted for 70% of the restored tooth surfaces. Twenty per cent of the individuals were daily smokers and 61% were taking drugs with hyposalivatory side‐effects. The mean saliva secretion rates were lower in the older groups compared with the ‘younger’ ones. The overall salivary counts of mutans streptococci and lactobacilli had increased during the period and the values were highest in the oldest age groups. Salivary levels of lactobacilli and mutans streptococci, number of teeth, daily numbers of cigarettes and drugs and oral hygiene were the best predictors of the incidence of caries. Conclusion: The findings indicate that there is an increased risk of dental caries with age owing to unfavourable caries‐related factors.