Clinical and microbiologic effects of lingual cervical coverage by removable partial dentures.

PURPOSE: The effect of gingival coverage by removable partial dentures (RPDs) on bacterial accumulation has not been sufficiently established. The aim of this study was to evaluate the periodontal and microbiologic reactions to mandibular major connectors. It was hypothesized that the use of a lingual plate increases the risk of periodontal disease. MATERIALS AND METHODS: Fourteen subjects (mean age: 69.0 years) received oral hygiene instructions and ultrasonic debridement prior to examination. Each subject received an experimental RPD incorporating either a lingual bar or lingual plate for the first 8 weeks and was then switched to the other option for the next 8 weeks. Clinical parameters (Plaque Index, Gingival Index, probing depth, and tooth mobility) were recorded. Subgingival plaque samples were collected from the periodontal pocket in the test site to measure the colonization of periodontal pathogens after the use of each denture. RESULTS: The mean probing depth was significantly greater after use of the lingual plate compared to the lingual bar (P < .05), whereas the type of connector did not affect the levels of any of the microbial species. All subjects that exhibited at least one bacterial species showed smaller numbers of microorganisms at the second examination than at the first. CONCLUSIONS: The lingual cervical coverage did not precipitate the accumulation of anaerobic microorganisms, although it could potentially induce gingival inflammation. The results suggest that a lingual plate can be used as safely as a lingual bar if oral and denture hygiene are carefully monitored.

Periodontal conditions during the pregnancy associated with periodontal pathogens.

AIM: To describe the bacterial associations in the periodontal pockets of pregnant women and to correlate the presence of Prevotella intermedia, Tannerella forsythia (T. forsythia), Treponema denticola (T. denticola), Aggregatibacter actinomycetemcomitans, and Porphyromona gingivalis (P. gingivalis) with periodontal parameters of severity. METHODS: The analysis was performed with 150 pregnant women. The examination consisted of an evaluation of bleeding, suppuration, probing depths, clinical attachment levels, hypermobility scores, the Silness and Löe Plaque Index, and the Löe and the Silness Gingival Index. Each periodontal pathogen was identified by polymerase chain reaction. RESULTS: A statistically-significant association was observed (P < 0.01) between P. gingivalis and T. forsythia, between P. gingivalis and T. denticola, and between T. forsythia and T. denticola. Age was observed to be a risk factor in the development of moderate periodontitis (odds ratio [OR] = 4.92, 95% confidence interval [CI] = 1.1-21.3, P = 0.0328). Age was significantly associated with increased pocket depth and plaque index (OR = 6.36, 95% CI = 1.8-22.2, P = 0.0037). In pregnant women, the presence of P. gingivalis was found to increase the risk of developing a clinical attachment level ≥ 5 mm. CONCLUSION: A high prevalence of P. gingivalis in pregnant women, especially in combination with T. forsythia and T. denticola, was associated with an increased risk of developing moderate periodontitis, and that association was more marked in pregnant women aged 30 years or older.

Isolation and identification of Porphyromonas spp. and other putative pathogens from cats with periodontal disease.

The purpose of this study was to evaluate the subgingival microbiota and determine the most prevalent periodontal pathogens implicated in feline periodontal disease and to correlate these findings with the clinical periodontal status. Subgingival microbiological samples were taken under sedation from 50 cats with clinical signs of periodontal disease. Pooled paper point samples from 4 selected subgingival sites were cultured on blood agar and on Dentaid-1 medium. Suspected pathogens were identified, subcultured, and preserved. The association between the microbiological findings and the clinical status was studied using correlation coefficients (CC). In addition, cats were stratified in subgroups according to presence of putative pathogens, and comparisons were carried out using unpaired t-test. Three bacterial species were frequently detected including Porphyromonas gulae (86%), Porphyromonas circumdentaria (70%) and Fusobacterium nucleatum (90%). The mean proportion of total flora was high for P. gulae (32.54%), moderate for P. circundentaria (8.82%), and low for F. nucleatum (3.96%). Among the clinical variables, tooth mobility was correlated (CC > 0.50, p < 0.001) with recession, pocket depth, attachment level, gingival index, and calculus index (CC = 0.29, p = 0.04) as well as with total bacterial counts (CC = 0.38, p = 0.006). Cats with more than 10% of P. gulae showed significantly more mobility (p = 0.014) and recession (p = 0.038), and a tendency for deeper probing pocket depths (p = 0.084) and attachment loss (p = 0.087). The results from this cross-sectional study confirmed that P. gulae is the most relevant pathogen in periodontal disease in cats.

A combination of clinical and microbiological management of generalized aggressive periodontitis in primary teeth. A case report.

BACKGROUND: Generalized aggressive periodontitis (GAP) in primary teeth is a rare periodontal disease that occurs during or soon after eruption of the primary teeth. An association with systemic diseases is a possibility. CASE REPORT: A 4-year-old Brazilian girl presented with GAP involving the entire primary dentition. The patient and her parents and sister were subjected to microbiological testing to identify the microorganisms involved in the disease. The patient underwent tooth extraction to eradicate the disease and received a prosthesis for the restoration of masticatory function. After the permanent teeth erupted, fixed orthodontic appliances were place to restore dental arch form and occlusion. CONCLUSIONS: The results show the importance of an early diagnosis of GAP and of a multidisciplinary approach involving laboratory and clinical management to treat the disease and to restore masticatory function, providing a better quality of life for patients.

Investigation of six selected bacterial species in endo-periodontal lesions.

AIM: To investigate and determine possible associations of six tested bacteria belonging to 'orange' and 'green' complexes, in endo-periodontal lesions: Parvimonas micra, Fusobacterium nucleatum, Campylobacter rectus, Eubacterium nodatum, Eikenella corrodens and Capnocytophaga sputigena. METHODOLOGY: Forty-six patients presenting with different types of endo-periodontal lesions were investigated. Clinical examinations, periapical radiographs and microbiological sampling from the canal system (endo) and periodontal pockets (perio) were performed. Qualitative and semiquantitative evaluation of bacteria was performed by polymerase chain reaction (PCR) and DNA-DNA hybridization (micro-IDent plus; Hain Lifescience, Germany). RESULTS: Extremely high bacterial loads in endodontic samples were recorded for P. micra, F. nucleatum and C. sputigena, while periodontal samples were often colonized by the same species, plus C. rectus. Significant association was recorded between F. nucleatum-endo and P. micra-endo (P = 0.03, Fisher's exact test). There was marginal evidence of associations between: (i) C. sputigena-endo and C. sputigena-perio (P = 0.06, Fisher's exact test); (ii) P. micra-endo and P. micra-perio (P = 0.05, Fisher's exact test). Sensitivity to percussion was associated with an increased chance of cases with P. micra-endo (P = 0.03, Pearson chi-square test). CONCLUSION: The findings suggest that F. nucleatum, P. micra and C. sputigena may play a role in the pathogenesis of endo-periodontal lesions.

Microbiologic evaluation of compromised periodontal sites before and after immediate intrasocket implant placement.

This study aimed to elucidate the changes in subgingival microflora before the extraction of severely periodontally involved teeth and 1 year after immediate implant placement and provisionalization without flap elevation. Clinical parameters were recorded for 20 maxillary anterior teeth from 10 individuals before and after implant treatment. The clinically observed improvement in the soft tissues was found to be compatible with a less pathogenic flora. Concentrations of periodontopathogens in the periodontal sites were heavily reduced when transformed into peri-implant sites, whereas the relevant counts of the beneficial microorganisms were increased.

Virulence genes of Porphyromonas gingivalis W83 in chronic periodontitis.

OBJECTIVE: To identify virulence genes found in highly virulent strains of Porphyromonas gingivalis (P. gingivalis) among Chinese patients with chronic periodontitis and to evaluate the association of these virulence genes with clinical parameters and with periodontal tissue destruction. MATERIAL AND METHODS: Suppression subtractive hybridization was applied to acquire short gene fragments harbored only in virulent strains of P. gingivalis W83. Eighteen genes, which were present in P. gingivalis W83 but absent from P. gingivalis ATCC 33277, were labeled with Cy5 and used as probes in DNA microarray hybridization to analyze DNA of P. gingivalis isolated from chronic periodontitis patients. RESULTS: Spearman correlation analysis revealed 10 genes correlated with probing depth, clinical attachment loss, and tooth mobility (p<0.05). CONCLUSION: These genes may provide an important clue towards our understanding the mechanism of occurrence and the development of periodontal disease.

Molecular analysis of Filifactor alocis, Tannerella forsythia, and treponema denticola associated with primary endodontic infections and failed endodontic treatment.

The aim of this study was to investigate the presence of strict anaerobes such as Filifactor alocis, Tannerella forsythia, and Treponema denticola in primary and secondary root-infected canals with periapical lesions by molecular analysis and the association of these species with specific endodontic signs and symptoms. Microbial samples were taken from 100 root canals, 50 with necrotic pulp tissues (NPT, primary infection), and 50 with failed endodontic treatment (FET, secondary infection). DNA was extracted from the samples, which were analyzed for the presence of three endodontic pathogens using species-specific primers and PCR. F. alocis were isolated from 23 canals with NPT and 12 canals with FET; T. forsythia from 12 canals with NPT and three canals with FET; T. denticola from 19 canals with NPT and 12 canals with TEP. Suggested associations were found between primary infection and the presence of F. alocis and T. forsythia (both p < 0.05). In particular, associations were found between: pain and F. alocis; swelling and F. alocis; tenderness to percussion and T. forsythia; mobility and T. forsythia and T. denticola; wet canals and F. alocis, T. forsythia, and T. denticola; purulent exsudate and F. alocis, T. forsythia and T. denticola; abscess and F. alocis, T. forsythia, and T. denticola (all p < 0.05). The findings of this study indicated that F. alocis, T. forsythia, and T. denticola seem to be associated with endodontic signs and symptoms. Additionally, F. alocis and T. forsythia were detected more frequently in teeth with necrotic pulp than in teeth with failing endodontic treatment.

Localized aggressive periodontitis in a six-year-old: a case report.

The purpose of this report was to describe an approach to diagnose and effectively treat a pediatric patient with localized aggressive periodontitis. A 6-year-old female presented with clinical and radiographic evidence of severe attachment loss around several primary teeth. She had no history of systemic disease, periodontal disease, or caries prior to the periodontal abscess that prompted her referral. Routine immunological tests did not reveal any functional defects, but DNA testing for periodontal pathogens revealed the presence of all 8 aggressive periodontal pathogens assayed. Treatment consisted of the extraction of 2 severely affected primary teeth, increased frequency of recall appointments, and administration of systemic antibiotics. The patient's periodontal condition was stabilized 18 months post-treatment, and the 8 pathogens were no longer at detectable levels. With a treatment goal of preventing disease progression into the erupting permanent dentition, this treatment regimen provides an effective alternative to more aggressive strategies.

Species-specific DNA probe for the detection of Porphyromonas gingivalis from adult Chinese periodontal patients and healthy subjects.

BACKGROUND: It has been reported that Porphyromonas gingivalis is closely associated with chronic periodontitis and its detection has been recommended as a routine marker for periodontal diagnosis. The purpose of this study was to evaluate the sensitivity and specificity of a DNA probe to detect P. gingivalis in adult Chinese periodontitis patients as well as to find a rapid and convenient method to detect P. gingivalis in clinical practice. METHODS: A total of 26 bacterial strains (20 reference strains and 6 clinical isolates) were collected, of which 5 were P. gingivalis and 21 were heterologous species. A DNA fragment of 542 bp, which encodes the fimbriae subunit protein (fimA) of P. gingivalis, was obtained by polymerase chain reaction (PCR) and molecular cloning techniques and used to construct the DNA probe, labeled with 32P or with digoxigenin. The constructed DNA probe was used to detect P. gingivalis in specimens collected from the periodontal pockets of 100 patients clinically confirmed with chronic periodontitis. One hundred periodontally healthy persons served as a control group. RESULTS: Positive reactions were seen in all 5 strains of P. gingivalis while no visible reaction was found in other species. The DNA probe was capable of detecting as few as 100 P. gingivalis cells in samples. A significant difference in the positive rates of P. gingivalis between the periodontitis patients and the control group was found (P<0.01). In addition, the amount of detected P. gingivalis was positively correlated with the extent of tooth mobility, depth of periodontal pockets, and patient age (P<0.01). CONCLUSION: The DNA probe is specific and sensitive for the detection of P. gingivalis in chronic periodontitis specimens and may be a suitable method for the clinical diagnosis of chronic periodontitis.

Antibody responses to suspected periodontal pathogens in elderly subjects with periodontal disease.

Little is known about the relationship of aging to periodontal disease. The immune response undergoes aging-related changes resulting in loss of functional capacity. The aim of this study was to investigate the relationship between levels of serum IgG antibodies against suspected periodontal pathogenic microorganisms to the presence or absence of periodontal disease in an elderly (65-75 yrs) population. From this study, we obtained information concerning: (1) the ability to differentiate elderly individuals without disease from those with disease by their levels of antibodies against periodontal pathogens and (2) which periodontal pathogen(s) triggered those responses. IgG anti- Porphyromonas gingivalis (strains W83 and 381) levels in the serum of elderly patients with severe periodontal disease were the only antibody responses measured which were elevated compared to the elderly control group of subjects with no periodontal disease. Anti- Prevotella intermedia IgG levels in both elderly patient groups were depressed compared to anti- P. intermedia levels in the young normal control subjects. Serum IgG antibody levels to six other plaque microorganisms did not differentiate between diseased and normal, elderly or young subjects. This data suggested that P. gingivalis was associated with periodontal disease in this elderly group of individuals and that those elderly individuals were able to respond with a normal IgG immune response.

Periodontal microbiota of mobile and non-mobile teeth.

The mechanism of accelerated periodontal destruction around teeth with occlusal trauma and increased mobility remains unclear. One possibility is that tooth mobility creates a subgingival environment conducive to overgrowth by periodontal pathogens. This study compared the subgingival microflora in mobile and non-mobile teeth of 35 adults on supportive maintenance therapy and 15 with untreated adult periodontitis. In each subject, subgingival paper-point samples were obtained from a mobile tooth with a probing depth of 4 mm or greater and from a non-mobile tooth with similar probing depth and gingival index. Samples were transported in VMGA III medium. Pockets around mobile teeth harbored significantly higher proportions of Campylobacter rectus (P = 0.001) and Peptostreptococcus micros (P = 0.05) than pockets with non-mobile teeth. Mobile teeth also tended to show elevated levels of Porphyromonas gingivalis, but this did not reach statistical significance. This study suggests that tooth mobility may constitute a risk for periodontal breakdown due to an increased subgingival occurrence of specific periodontopathogens. This hypothesis needs to be verified in longitudinal clinical and microbiological studies.