Salivary detection of periodontopathic bacteria in periodontally healthy children

BACKGROUND: Salivary occurrence of periodontopathic bacteria is of interest especially in children as a risk indicator for the transmission, development and control of periodontal disease. We assessed the prevalence of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, Prevotella nigrescens and Treponema denticola as microbial complexes in the saliva of children with mixed dentition and healthy gingiva. MATERIALS AND METHODS: Paraffin-stimulated saliva samples were collected from 41 children (22 boys and 19 girls), aged 6-13 years old. Gingival health was determined during the initial screening exam. The test bacteria were identified using a 16S rRNA-based PCR analysis. RESULTS: P. nigrescens was the most frequent species (80%), followed by T. denticola (32%), A. actinomycetemcomitans (24%) and P. gingivalis (12%). P. intermedia and T. forsythia were not detected. P. nigrescens was also common species in combinations. Paired and triple bacterial combinations were found in 24% and 20% of all children, respectively. There was no positive association between bacterial combinations in colonization and subject's gender (P>0.05, Fisher exact test). CONCLUSION: The salivary presence of P. nigrescens, T. denticola, A. actinomycetemcomitans and P. gingivalis but not P. intermedia and T. forsythia can occur in childhood without clinical signs of gingival disease. Thus, the possible risk of bacterial transmissions through saliva and, the need to screen for periodontal pathogens should be considered before mixed dentition.     

Rapid detection and quantification of five periodontopathic bacteria by real-time PCR

The quantity of periodontopathic bacteria in plaque samples is an important determinant for understanding the etiologic role of bacteria. The real-time PCR method was used to detect and quantify periodontopathic bacteria, such as Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Porphyromonas gingivalis, Treponema denticola, and Treponema socranskii, in saliva and subgingival plaque samples. There was good agreement between the results of conventional PCR and real-time PCR methods. Using the LightCycler system we were able to determine the amount of periodontopathic bacteria within an hour. The real-time PCR method was linear for samples containing from 10(3) to more than 10(8) cells (r2 = 0.999). The application of the real-time PCR method should be useful in the rapid detection and quantification of periodontopathic bacteria in clinical samples.     

Periodontitis,periodontopathic bacteria and lactoferrin

Lactoferrin (LF) is a component of saliva and is suspected to be a defense factor against oral pathogens including Streptococcus mutans and Candida albicans. Periodontitis is a very common oral disease caused by periodontopathic bacteria. Antimicrobial activities and other biological effects of LF against representative periodontopathic bacteria, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia, have been widely studied. Association of polymorphisms in LF with incidence of aggressive periodontitis and the role of LF in the gingival crevicular fluid as a marker of periodontitis severity have also been reported. Periodontopathic bacteria reside as a biofilm in supragingival and subgingival plaque. Our recent study indicated that LF exhibits antibacterial activity against planktonic forms of P. gingivalis and P. intermedia at higher concentrations, and furthermore, LF effectively inhibits biofilm formation and reduces the established biofilm of these bacteria at physiological concentrations. A small-scale clinical study indicated that oral administration of bovine LF reduces P. gingivalis and P. intermedia in the subgingival plaque of chronic periodontitis patients. LF seems to be a biofilm inhibitor of periodontopathic bacteria in vitro and in vivo.     

Periodontal status in an Italian young adult population. Prevalence and relationship with periodontopathic bacteria

To determine the prevalence of periodontitis in an Italian young adult population and the relationship with Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia in subgingival plaque. A full-mouth periodontal and oral examination was performed in 70 subjects. Dental and behaviour habits were assessed with a standardised questionnaire. Subgingival plaque samples were collected from the deepest pocket of the first molars in each quadrant with a sterile curette. A. actinomycetemcomitans, P. gingivalis and P. intermedia were detected using a multiplex polymerase chain reaction. At subject level, the prevalence of bleeding on probing, calculus, normal pocket depth (PD), PD > 5mm and bacterial positivity were 44.8%, 43.3%, 22.9%, 11.4% and 95.7%, respectively. At quadrant level bacterial prevalence was 79.4%; P. intermedia was the most common bacteria (79.0%); A. actinomycetemcomitans had a prevalence of 40.8%. A significant linear trend across categories of gingival conditions (healthy, bleeding on probing, calculus presence) was detected for P. intermedia (p = 0.0038) and A. actinomycetemcomitans (p = 0.00005) proportions. No significant association was observed between pathogenic bacteria and PD, nor with behavioural attitudes. Gingival conditions are found to be a good predictors (VPP = 85%) for periodontopathic bacteria. For the Italian population, as no data are present, prospective longitudinal studies are needed to examine the relationship between PD and bacteria presence with periodontal disease onset and/or progression.     

种植修复后牙周菌群在不同时期变化的定量研究

目的观察种植修复后牙周菌群在不同时期的变化,比较牙周病人群和健康人群种植术后菌群分布差异。方法选择牙种植患者28例,接受37颗种植修复（无牙周病史19颗,有牙周病史18颗）,采取前后对照设计。采用细菌分离鉴定及菌落形成单位计数的检测方法,以正常同名天然牙为基线对照,追踪观察愈合基台龈袖口、全冠修复后1周、负荷12个月后牙龈沟菌丛变化情况。结果种植体龈沟液内的细菌数量增加构成日趋复杂,在愈合基台期细菌数量最低,冠修复后1年,两组人群的菌群数量和构成差异有显著性（P〈0．05）,而健康人群成功种植体和天然牙有相似的菌群构成;但以往有牙周病史的患者,种植体植入区域内普遍有牙周病原体量的增加。结论随着时间的延长,具有牙周病史的患者的种植体周围炎的风险增加。     

Modulation of Wnt5a expression by periodontopathic bacteria

Wingless proteins, termed Wnt, are involved in embryonic development, blood cell differentiation, and tumorigenesis. In mammalian hematopoiesis, Wnt signaling is essential for stem-cell homeostasis and lymphocyte differentiation. Recent studies have suggested that these molecules are associated with cardiovascular diseases, rheumatoid arthritis, and osteoarthritis. Furthermore, Wnt5a signaling is essential for the general inflammatory response of human macrophages. Periodontitis is a chronic inflammatory disease caused by gram-negative periodontopathic bacteria and the resultant host immune response. Periodontitis is characterized by loss of tooth-supporting structures and alveolar bone resorption. There have been no previous reports on Wnt5a expression in periodontitis tissue, and only few study reported the molecular mechanisms of Wnt5a expression in LPS-stimulated monocytic cells. Using RT-PCR, we demonstrated that Wnt5a mRNA expression was up-regulated in chronic periodontitis tissue as compared to healthy control tissue. P. gingivalis LPS induced Wnt5a mRNA in the human monocytic cell line THP-1 with a peak at 4 hrs after stimulation. P. gingivalis LPS induced higher up-regulation of Wnt5a mRNA than E. coli LPS. The LPS receptors TLR2 and TLR4 were equally expressed on the surface of THP-1 cells. P. gingivalis LPS induced IκBα degradation and was able to increase the NF-κB binding activity to DNA. P. gingivalis LPS-induced Wnt5a expression was inhibited by NF-κB inhibitors, suggesting NF-κB involvement. Furthermore, IFN-γ synergistically enhanced the P. gingivalis LPS-induced production of Wnt5a. Pharmacological investigation and siRNA experiments showed that STAT1 was important for P. gingivalis LPS-induced Wnt5a expression. These results suggest that the modulation of Wnt5a expression by P. gingivalis may play an important role in the periodontal inflammatory process and serve a target for the development of new therapies.     

Detection of DNA from periodontal pathogenic bacteria in biofilm obtained from waterlines in dental units

Direct person-to-person transmission of periodontal bacteria through saliva has recently been widely reported and dental units have been demonstrated to retract saliva from patients under treatment and to release it into the mouths of subjects undergoing the next operation. In this study the presence of a group of periodontal pathogenic bacteria inside waterlines in dental units was investigated using polymerase chain reaction (PCR) based methods. Briefly, 18 dental units of three different manufacturers were studied. Dental units were divided into two groups according to their prevalent use in routine practice. The first group consisted of nine dental units characterized by the frequent use of high-speed dental hand-pieces directly inside the mouth and in contact with patients' saliva. The second group, as a control, consisted of nine dental units where high-speed dental hand-pieces were not in use. A one cm section of the waterline tubing connected to the high-speed hand-piece was removed from each dental unit to evaluate the presence of DNA of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus, Treponema denticola. Two specimens were positive for Prevotella intermedia DNA. All the positive results were from samples obtained from dental units categorised in the first group. These findings clearly suggest that dental units have the potential to transmit periodontal pathogens. Manufacturers should be invited to design dental units that incorporate automated devices to disinfect DUWLs between patients with minimal effort by dental staff.     

Relationship of cariogenic bacteria levels with periodontal status and root surface caries in elderly Japanese

Objective: The relationship of the levels of cariogenic bacterial species with periodontal status and decayed root surfaces was investigated in elderly Japanese subjects. Methods: Three hundred and sixty‐eight individuals (each 75 years old) were examined for periodontal status (pocket depth, attachment loss), root surface caries and salivary levels of mutans streptococci (MS) and lactobacilli (LB). Results: Values >4 mm of attachment loss (rAL4) and for average attachment loss (aAL) of sites measured were significantly higher in subjects with LB than those without. Multiple regression analysis also showed a correlation between aAL and rAL4 values with the presence of LB (aAL p = 0.003; rAL4 p = 0.002). Further, multiple regression analysis of interacting factors regarding decayed root surfaces showed that LB carriers had a greater incidence of decayed root surface caries (p = 0.003), while MS and LB levels were correlated to the number of decayed root surfaces (LB p = 0.010; MS p = 0.026). Conclusion: Our results indicate that considerable attachment loss elevates the possibility of having LB, thus increasing the risk of root surface caries. It was also found that LB and MS measurements may be useful indicators of decayed root surfaces in elderly individuals with attachment loss.     

牙周可疑致病菌与下呼吸道感染的关系

牙菌斑生物膜是牙周炎的始动因子。研究发现,牙周炎与全身多器官或系统的感染性疾病有关,如心脑血管疾病、糖尿病、消化道和呼吸道疾病。近年来,牙周炎与呼吸道疾病之间的关系备受关注,本文将近期对牙周可疑致病菌感染下呼吸道的途径及其作用研究做简要综述。     

Colonisation of the oral cavity by periodontopathic bacteria in complete denture wearers

doi: 10.1111/j.1741‐2358.2011.00506.x Colonisation of the oral cavity by periodontopathic bacteria in complete denture wearers Objective: The purpose of this study was to investigate colonisation by periodontopathic bacteria and the sites of colonisation in elderly upper and lower complete denture wearers. We also investigated the relationship between level of oral hygiene and colonisation by periodontopathic bacteria. Materials and methods: Forty edentulous and 37 dentate volunteers participated in this study. Samples were collected from whole saliva, and levels of Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia and Fusobacterium nucleatum were determined by PCR Invader technology. Detection of these species on oral mucosal and denture surfaces was performed by PCR. Fisher’s exact test was used for the statistical analysis. Cluster analysis was employed to investigate trends in the periodontopathic bacteria flora in each sampling area. Results: Detection rates of periodontopathic bacteria in whole saliva were lower under edentulous conditions than under dentulous conditions, except for A. actinomycetemcomitans and F. nucleatum (p < 0.01). Detection rate of F. nucleatum was the highest in all areas. A positive correlation was observed between DNA quantification of P. gingivalis and number of Candida species in saliva. Cluster analysis of the test species identified two clusters. Tongue‐coating status was associated with the detection rate of all periodontopathic bacteria investigated, and denture plaque status was associated with the detection rate of T. denticola and F. nucleatum. Conclusion: Results indicate the presence of periodontopathic bacteria under edentulous conditions and that the status of oral hygiene of the mucosal or denture surfaces affects colonisation by T. denticola and F. nucleatum.     

Salivary levels of immunoglobulin and dental caries in children

IgG, IgA, IgM and lysozyme levels were determined in whole unstimulated saliva from ten children aged seven-nine years. IgA levels were significantly higher (p less than 0.05) in caries-susceptible subjects when compared with the caries-free ones. High levels of IgG seemed to correlate with a high DMF score. No correlation was found between lysozyme levels and DMF score.     

General health, dental status and perceived dental treatment needs of an elderly population in Istanbul

doi: 10.1111/j.1741‐2358.2010.00363.x
General health, dental status and perceived dental treatment needs of an elderly population in Istanbul Background: Comprehensive data on the oral health status and dental treatment needs of the elderly population in Turkey are deficient. Objectives: This pilot study determined the general and dental health status, perceived medical and dental treatment needs of an elderly population dwelling in residential homes in Istanbul. Method: Subjects at three different residential homes, namely one belonging to the state and two supported by foundations in Istanbul (N=121, female: 63 and male: 58) were involved in this study. A detailed questionnaire was prepared and dental examinations were conducted. Information was collected related to age, education levels, financial status, current physical functional status, general health, mental health, previous dental history, current dental status, oral hygiene practices and denture hygiene of these elderly people. The prevalence of edentulism, the presence and type of dental prostheses, dental and denture status and denture cleanliness were further evaluated. Results: The three most prevalent reported general health problems were associated with genito‐urinary problems (24%) followed by cardiovascular (18%) and respiratory problems (14%) varying significantly between genders, with males suffering more from cardiovascular problems than females (p < 0.05). Females showed significantly higher gastrointestinal and orthopaedic problems than males (p < 0.05). Females were more frequently edentulous than males but denture hygiene was significantly better in females than in males (p < 0.05). Brushing frequency did not significantly increase denture hygiene (p = 0.6). More than one‐third of the subjects had not been to the dentist within the previous 5–10 years, mainly due to lack of demand, followed by the cost of the dental care and fear. More than two‐thirds of denture‐wearing subjects wore their dentures only during eating. Conclusions: There was significant perceived dental treatment and care need for the sample population of elderly studied.     

Prevalence of periodontopathic bacteria on the tongue dorsum of elderly people

Objectives: The aim of this study was to analyse the prevalence of oral bacteria on the dorsum of the tongue. In addition, the relationship between the number of teeth and the microflora present on the coating of the tongue in a population of 85‐year‐old people was assessed. Subjects and methods: Two hundred and five individuals (89 males, 116 females) from the same geographical area who were 85 years of age were examined. Five periodontopathic bacteria (Porphyromonas gingivalis, Tannerella forsythia, Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, and Treponema denticola) and one cariogenic bacterium (Streptococcus mutans) were analysed using a polymerase chain reaction assay of tongue samples from the population. Results: Periodontal bacteria‐positive individuals have more teeth than that of periodontal bacteria‐negative people. Between the periodontal bacteria‐positive and ‐negative individuals, there were significant differences in the mean number of teeth for P. gingivalis (p < 0.0001), T. denticola (p < 0.001), F. nucleatum (p = 0.002), and T. forsythia (p = 0.005), while there were no significant differences for A. actinomycetemcomitans (p = 0.998) or S. mutans (p = 0.147). Conclusions: A wide range of species, including anaerobes, was detected in 85‐year‐old subjects. It was found that the detection of periodontal bacteria on the tongue coating increased with the number of teeth. There was a positive relationship between the tooth number and periodontopathic bacteria, except for A. actinomycetemcomitans.These results suggest that tongue care is essential for preventing oral disease and needs to be part of any oral care programme in elderly people.     

Killing activity of LFchimera on periodontopathic bacteria and multispecies oral biofilm formation in vitro

Lactoferrin chimera (LFchimera), a heterodimeric peptide containing lactoferrampin (LFampin265–284) and a part of lactoferricin (LFcin17–30), possesses a broad spectrum of antimicrobial activity. However, there is no report on the inhibitory effects of LFchimera against multispecies oral biofilms. This study aimed to determine the effects of LFchimera in comparison to chlorhexidine digluconate (CHX) and minocycline hydrochloride (MH), on in vitro multispecies biofilms derived from subgingival plaque of periodontitis patients harboring Aggregatibacter actinomycetemcomitans. First the effects of LFchimera against planktonic and an 1-day old biofilm of the periodontopathic bacteria, A. actinomycetemcomitans ATCC 43718 were established. Then, the effects on biofilm formation and bacterial viability in the multispecies biofilm were determined by crystal violet staining and LIVE/DEAD BacLight Bacterial Viability kit, respectively. The results revealed that a significant reduction (P?<?0.05) in biofilm formation occurred after 15 min exposure to 20 µM of LFchimera or CHX compared to control. In contrast, MH at concentration up to 100 µM did not inhibit biofilm formation. The ratio of live/dead bacteria in biofilm was also significantly lower after 15 min exposure to 20 µM of LFchimera compared to control and 20–50 µM of CHX and MH. Altogether, the results obtained indicate that LFchimera is able to inhibit in vitro subgingival biofilm formation and reduce viability of multispecies bacteria in biofilm better than CHX and MH.     

Detection rates of periodontal bacteria and herpesviruses in different forms of periodontal disease

The aim was to investigate the detection rates of periodontal bacteria (Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, and Aggregatibacter actinomycetemcomitans) and herpesviruses (herpes simplex virus-1 [HSV-1], cytomegalovirus [CMV], and Epstein-Barr virus [EBV]) in different forms and severity of periodontal disease, and to compare them with those in periodontally healthy subjects. One hundred and twenty-nine patients participated in the study: 39 diagnosed with periodontal abscess (PA), 33 with necrotizing ulcerative periodontitis (NUP), 27 with chronic periodontitis (CP), and 30 participants with healthy periodontal tissue represented a healthy control group. All patients with periodontal disease (PA, NUP, and CP) were also divided into two groups according to the severity of their disease: moderate and severe periodontitis. The subgingival samples were collected from the periodontitis active sites and the detection of microorganisms was performed by end-point polymerase chain reaction analyses. The results revealed significantly higher detection rates of P. gingivalis, T. forsythia, and P. intermedia in all three groups of patients with periodontitis than in healthy participants. The highest detection rate of A. actinomycetemcomitans was noticed in CP, which was significantly higher than that in PA, NUP, and healthy control. The occurrence of EBV was significantly higher in NUP than in CP and healthy participants. CMV was detected significantly more frequently in PA and NUP than in CP and healthy participants. Comparisons among healthy participants and patients with moderate and severe periodontitis showed significantly higher detection rates of EBV and CMV in patients with severe forms of periodontitis than in healthy participants and those with moderate periodontitis.     

Sensory detection of food odour in relation to dental status,gender and age

The aim of this study was to investigate to what extent declining odour perception can be ascribed to dental status and oral hygiene habits, taking into account gender and age. Apparently healthy adults (n=182), ranging from 53 to 93 years (mean age=68.4) were tested. Information about oral hygiene habits (brushing teeth and cleaning dentures) and dental status was obtained by questionnaires. A validated objective procedure was used to measure sensory detection thresholds for isoamylacetate by an ascending method of limits. A significant negative correlation of odour perception with age was shown by the edentulous subjects which might reflect their wider age spread with many subjects over age 75. The evaluation of odour perception as a function of dental status shows no significant difference in odour perception between persons partial denture wearers, with natural teeth only or complete dentures. However, a tendency for lower odour perception was observed among male partial denture wearers, especially those reporting less frequent oral hygiene, which justifies further more detailed study.