Microbiological markers for prediction and assessment of treatment outcome following non-surgical periodontal therapy

Recent progress in materials development and biological properties of GTR membranes for periodontal regeneration

Chronic periodontal is a very common infection that instigates the destruction of oral tissue, and for its treatment, it is necessary to minimize the infection and the defects regeneration. Periodontium consists of four types of tissues: (a) cementum, (b) periodontal ligament, (c) gingiva, and 4) alveolar bone. In separated cavities, regenerative process also allows various cell proliferations. Guided tissue regeneration (GTR) is a potential procedure that favors periodontal regrowth; however, some limitations (such as ineffective hemostatic property, poor mechanical property, and improper biodegradation) are also associated with it. This review mainly emphasizes on the following areas: (a) a summarized overview of the periodontium and its immunological situations, (b) recently utilized treatments for regeneration of distinctive periodontal tissues; (c) an overview of GTR membranes available commercially, and the latest developments on the characterization and processing of GTR membrane material; and 4) the function of the different non-polymeric/polymeric materials, which are acting as drug carriers, antibacterial agents, nanoparticles, and periodontal barrier membranes to prevent periodontal inflammation and to improve the strength of the GTR membrane.

Molecular detection of feline and canine periodontal pathogens

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It is concluded that the feline oral flora is highly diverse than canine oral flora.

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Porphyromonas gingivalis, Prevotella nigrescens and Porphyromonas gulae were the dominant species in cats and dogs.

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T. forsythia, C. ochracea, and C. sputigena in cats and T. forsythia, C. ochracea, C. sputigena T. denticola and, E. corrodens, in dogs showed that the prevalence was lower than 10%. E. corrodens in cats and, P. intermedia, A. actinomycetemcomitans, and C. rectus in dogs were also isolated from the swab samples with less than 30% percentage.

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A balanced diet for cats and dogs should be provided to reduce the formation of residues in the oral flora. Daily rinsing with antiseptic solutions may also be helpful against the development of periodontal pathogens.

Periodontal disease is the most common infectious disease of cats and dogs which are strongly associated with periodontal pathogens. The primary etiologic factor in the formation of periodontal disease is microbial dental plaque accumulation on teeth. In our research, we aimed to investigate the presence of periodontal disease-related bacterial species in dental plaques of cats and dogs. Specimens collected from 50 cats and 51 dogs with periodontal disease examined in terms of periodontal pathogens by polymerase chain reaction (PCR) using primers directed to 16S rRNA and tdpA genes. Our findings indicate the presence of periodontal disease-related pathogens, especially Porphyromonas gingivalis (cats 96%, dogs 88%), Prevotella nigrescens (cats 90%, dogs 57%) and, Porphyromonas gulae (cats 70%, dogs 39%). In addition, the prevalence of Tannerella forthysia (cats 2%, dogs 4%) well-known pathogen in cats and dogs were isolated with an extremely low percentage.

Furthermore, our results suggest that the feline oral cavity microbiota has considerably more diversity than dogs. Consequently, daily oral hygiene practices may become essential for controlling the pathogenic bacteria which have clinical importance and in preventing the propagation of microorganisms in the oral cavity of cats and dogs.

Novel Bioactive and Therapeutic Dental Polymeric Materials to Inhibit Periodontal Pathogens and Biofilms

Periodontitis is a common infectious disease characterized by loss of tooth-supporting structures, which eventually leads to tooth loss. The heavy burden of periodontal disease and its negative consequence on the patient's quality of life indicate a strong need for developing effective therapies. According to the World Health Organization, 10⁻15% of the global population suffers from severe periodontitis. Advances in understanding the etiology, epidemiology and microbiology of periodontal pocket flora have called for antibacterial therapeutic strategies for periodontitis treatment. Currently, antimicrobial strategies combining with polymer science have attracted tremendous interest in the last decade. This review focuses on the state of the art of antibacterial polymer application against periodontal pathogens and biofilms. The first part focuses on the different polymeric materials serving as antibacterial agents, drug carriers and periodontal barrier membranes to inhibit periodontal pathogens. The second part reviews cutting-edge research on the synthesis and evaluation of a new generation of bioactive dental polymers for Class-V restorations with therapeutic effects. They possess antibacterial, acid-reduction, protein-repellent, and remineralization capabilities. In addition, the antibacterial photodynamic therapy with polymeric materials against periodontal pathogens and biofilms is also briefly described in the third part. These novel bioactive and therapeutic polymeric materials and treatment methods have great potential to inhibit periodontitis and protect tooth structures.

Efficacy of Acacia arabica gum as an adjunct to scaling and root planing in the treatment of chronic periodontitis: A randomized controlled clinical trial

Aim

The aim of the present study was to explore the adjunctive use of Acacia arabica gel in the treatment of chronic periodontitis.

Methods

Single centre, randomised, triple blind, controlled trial on mild to moderate chronic periodontitis patients; Group I (SRP + Acacia arabica, n = 40) and Group II (SRP + placebo, n = 40); were analysed for clinical improvements in periodontal pocket depth (PPD) and clinical attachment levels (CAL) at baseline, 15 and 90 days on application of gels. Gingival index and plaque index were assessed as secondary parameters.

Results

Statistically significant PPD reduction (p < .05) and CAL gain (p < .05) was observed with use of Acacia arabica gel. The reduction in sites with moderate PPD was observed more among Group I than Group II and the difference was statistically significant (p = .001). Secondary outcome variables; Plaque Index and Gingival Index showed better resolution with Acacia arabica gel.

Conclusion

Acacia arabica leads to better clinical outcomes in patients with mild to moderate chronic periodontitis with effective antiplaque and anti-gingivitis action. It may be recommended adjunct to SRP for maintenance in patients with mild to moderate chronic periodontitis.

Systemic antibiotics in the treatment of periodontitis

Despite the fact that several clinical studies have shown additional benefits when certain systemic antibiotics are used as adjuncts to periodontal treatment, clear guidelines for the use of these agents in the clinical practice are not yet available. Basic questions concerning the use of systemic antibiotics to treat periodontitis remain unanswered, such as: which drug(s) should be used; which patients would most benefit from treatment; which are the most effective protocols (i.e. doses and durations); and in which phase of the mechanical therapy should the drug(s) be administered? Although not all of those questions have been directly addressed by controlled randomized clinical trials, recent concepts related to the ecology of periodontal diseases, as well as the major advances in laboratory and clinical research methods that have occurred in the past decade, have significantly broadened our knowledge in this field. This article endeavored to provide a 'state of the art' overview on the use of systemic antibiotics in the treatment of periodontitis, based on the most recent literature on the topic as well as on a compilation of data from studies conducted at the Center of Clinical Trials at Guarulhos University (São Paulo, Brazil) from 2002 to 2012.

Antibiotic effects against periodontal bacteria in organ cultured tissue

Mechanical reduction of infectious bacteria by using physical instruments is considered the principal therapeutic strategy for periodontal disease; addition of antibiotics is adjunctive. However, local antibiotic treatment, combined with conventional mechanical debridement, has recently been shown to be more effective in periodontitis subjects with type 2 diabetes. This suggests that some bacteria may invade the inflamed inner gingival epithelium, and mechanical debridement alone will be unable to reduce these bacteria completely. Therefore, we tried to establish infected organ culture models that mimic the inner gingival epithelium and aimed to see the effects of antibiotics in these established models. Mouse dorsal skin epithelia were isolated, and periodontal bacteria were injected into the epithelia. Infected epithelia were incubated with test antibiotics, and colony-forming ability was evaluated. Results indicated that effective antibiotics differed according to injected bacteria and the bacterial combinations tested. Overall, in organ culture model, the combination of amoxicillin or cefdinir and metronidazole compensate for the effects of less effective bacterial combinations on each other. This in vitro study would suggest effective periodontal treatment regimens, especially for severe periodontitis.

Detection of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans after Systemic Administration of Amoxicillin Plus Metronidazole as an Adjunct to Non-surgical Periodontal Therapy: A Systematic Review and Meta-Analysis

Objective: To evaluate the variations in the detection of Porphyromonas gingivalis and/or Aggregatibacter actinomycetemcomitans before and after systemic administration of amoxicillin plus metronidazole in association with non-surgical periodontal therapy (NSPT).

Background: The adjunctive use of antibiotics has been advocated to improve the clinical outcomes of NSPT. However, no systematic review has investigated the microbiological benefit of this combination.

Materials and Methods: An electronic search was conducted up to December 2015. Randomized clinical trials comparing the number of patients testing positive for P. gingivalis and/or A. actinomycetemcomitans before and after NSPT with (test group) or without (control group) amoxicillin plus metronidazole were included. The difference between groups in the variation of positive patients was calculated using the inverse variance method with a random effects model.

Results: The frequency of patients positive for A. actinomycetemcomitans was decreased by 30% (p = 0.002) and by 25% (p = 0.01) in the test group compared to the control group at 3- and 6-month follow-up, respectively. Similar findings were observed when considering the frequency of patients positive for Porphyromonas gingivalis, with a reduction by 28% (p < 0.0001), 32% (p < 0.0001), and 34% (p = 0.03) in the test group compared to the control group at 3-, 6-, and 12-month follow-up, respectively.

Conclusion: The systemic administration of amoxicillin plus metronidazole as an adjunct to NSPT significantly decreased the number of patients positive for P. gingivalis and A. actinomycetemcomitans compared with periodontal therapy alone or with a placebo.

Evaluation of a novel immunochromatographic device for rapid and accurate clinical detection of Porphyromonas gingivalis in subgingival plaque

An important goal for the improved diagnosis and management of infectious and inflammatory diseases, such as periodontitis, is the development of rapid and accurate technologies for the decentralized detection of bacterial pathogens. The aim of this prospective multicenter study was to evaluate the clinical use of a novel immunochromatographic device with monoclonal antibodies for the rapid point-of-care detection and semi-quantification of Porphyromonas gingivalis in subgingival plaque. Sixty-three patients with chronic periodontitis and 28 periodontally healthy volunteers were subjected to clinical and microbiological examinations. Subgingival plaque samples were analyzed for the presence of P. gingivalis using a novel immunochromatography based device DK13-PG-001, designed to detect the 40k-outer membrane protein of P. gingivalis, and compared with a PCR-Invader method. In the periodontitis group, a significant strong positive correlation in detection results was found between the test device score and the PCR-Invader method (Spearman rank correlation, r=0.737, p<0.0001). The sensitivity, specificity, and positive and negative predictive values of the test device were 96.2%, 91.8%, 90.4% and 96.7%, respectively. The detection threshold of the test device was determined to be approximately 10(4) (per two paper points). There were significant differences in the bacterial counts by the PCR-Invader method among groups with different ranges of device scores. With a cut-off value of ≥0.25 in device score, none of periodontally healthy volunteers were tested positive for the subgingival presence of P. gingivalis, whereas 76% (n=48) of periodontitis subjects were tested positive. There was a significant positive correlation between device scores for P. gingivalis and periodontal parameters including probing pocket depth and clinical attachment level (r=0.317 and 0.281, respectively, p<0.01). The results suggested that the DK13-PG-001 device kit can be effectively used for rapid, chair-side detection and semi-quantification of P. gingivalis in subgingival plaque.

TRIAL REGISTRATION

UMIN Clinical Trials Registry (UMIN-CTR) UMIN000011943.

Influence of periodontitis on abdominal aortic aneurysms

Periodontitis is known to be a risk factor for abdominal aortic aneurysm (AAA). However, the influence of periodontitis on AAA development is to be elucidated. This article is to review the relationship between periodontitis and AAA. We focused on the roles of specific periodontopathic bacteria in AAA, matrix metalloproteinases and toll-like receptors in the pathophysiology in the section of experimental analysis. Furthermore, we showed clinical data of periodontitis in patients with AAA. We concluded that periodontal pathogens play a critical role in the AAA development.

Development of an in vitro periodontal biofilm model for assessing antimicrobial and host modulatory effects of bioactive molecules

Background

Inflammation within the oral cavity occurs due to dysregulation between microbial biofilms and the host response. Understanding how different oral hygiene products influence inflammatory properties is important for the development of new products. Therefore, creation of a robust host-pathogen biofilm platform capable of evaluating novel oral healthcare compounds is an attractive option. We therefore devised a multi-species biofilm co-culture model to evaluate the naturally derived polyphenol resveratrol (RSV) and gold standard chlorhexidine (CHX) with respect to anti-biofilm and anti-inflammatory properties.

Methods

An in vitro multi-species biofilm containing S. mitis, F. nucleatum, P. gingivalis and A. actinomycetemcomitans was created to represent a disease-associated biofilm and the oral epithelial cell in OKF6-TERT2. Cytotoxicity studies were performed using RSV and CHX. Multi-species biofilms were either treated with either molecule, or alternatively epithelial cells were treated with these prior to biofilm co-culture. Biofilm composition was evaluated and inflammatory responses quantified at a transcriptional and protein level.

Results

CHX was toxic to epithelial cells and multi-species biofilms at concentrations ranging from 0.01-0.2%. RSV did not effect multi-species biofilm composition, but was toxic to epithelial cells at concentrations greater than 0.01%. In co-culture, CHX-treated biofilms resulted in down regulation of the inflammatory chemokine IL-8 at both mRNA and protein level. RSV-treated epithelial cells in co-culture were down-regulated in the release of IL-8 protein, but not mRNA.

Conclusions

CHX possesses potent bactericidal properties, which may impact downstream inflammatory mediators. RSV does not appear to have bactericidal properties against multi-species biofilms, however it did appear to supress epithelial cells from releasing inflammatory mediators. This study demonstrates the potential to understand the mechanisms by which different oral hygiene products may influence gingival inflammation, thereby validating the use of a biofilm co-culture model.

Short-term microbiological effects of scaling and root planing and essential-oils mouthwash in Chinese adults

OBJECTIVE

To assess the short-term effect of scaling and root planing (SRP) and essential-oils mouthwash on the levels of specific bacteria in Chinese adults.

METHODS

Fifty Chinese adults with chronic periodontitis were randomly assigned to full-mouth SRP or a 7-d essential-oils mouthwash regimen. In addition, 22 periodontally healthy adults used essential-oils mouthwash for 7 d. Clinical examination and plaque/saliva sampling were performed at baseline and on Day 7. Quantitative real-time polymerase chain reaction (PCR) was used to measure Aggregatibacter actinomycetemcomitans (Aa), Fusobacterium nucleatum (Fn), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), and total bacterial loads in saliva, supra- and sub-gingival plaque samples.

RESULTS

The detection frequencies of four tested species remained unchanged after either treatment. However, the bacterial loads of Fn, Pg, and Pi were significantly reduced by SRP; the mean reduction of bacterial counts in saliva ranged from 52.2% to 62.5% (p<0.01), in supragingival plaque from 68.2% to 81.0% (p<0.05), and in subgingival plaque from 67.9% to 93.0% (p<0.01). Total bacterial loads were reduced after SRP in supra- and sub-gingival plaque (p<0.05). Essential-oils mouthwash reduced Fn levels in supragingival plaque by a mean of 53.2%, and reduced total bacterial loads in supra- and sub-gingival plaque (p<0.01). In subgingival plaque from periodontal patients, Pg and Pi reductions were high after SRP compared to essential-oils mouthwash (93.0% vs. 37.7% and 87.0% vs. 21.0%, p<0.05). No significant bacterial reduction was observed in periodontally healthy subjects using essential-oils mouthwash.

CONCLUSIONS

SRP and essential-oils mouthwash both have an impact on saliva and gingival plaque flora in Chinese periodontitis patients in 7 d, with greater microbiological improvement by SRP.

Oxantel disrupts polymicrobial biofilm development of periodontal pathogens

Bacterial pathogens commonly associated with chronic periodontitis are the spirochete Treponema denticola and the Gram-negative, proteolytic species Porphyromonas gingivalis and Tannerella forsythia. These species rely on complex anaerobic respiration of amino acids, and the anthelmintic drug oxantel has been shown to inhibit fumarate reductase (Frd) activity in some pathogenic bacteria and inhibit P. gingivalis homotypic biofilm formation. Here, we demonstrate that oxantel inhibited P. gingivalis Frd activity with a 50% inhibitory concentration (IC50) of 2.2 μM and planktonic growth of T. forsythia with a MIC of 295 μM, but it had no effect on the growth of T. denticola. Oxantel treatment caused the downregulation of six P. gingivalis gene products and the upregulation of 22 gene products. All of these genes are part of a regulon controlled by heme availability. There was no large-scale change in the expression of genes encoding metabolic enzymes, indicating that P. gingivalis may be unable to overcome Frd inhibition. Oxantel disrupted the development of polymicrobial biofilms composed of P. gingivalis, T. forsythia, and T. denticola in a concentration-dependent manner. In these biofilms, all three species were inhibited to a similar degree, demonstrating the synergistic nature of biofilm formation by these species and the dependence of T. denticola on the other two species. In a murine alveolar bone loss model of periodontitis oxantel addition to the drinking water of P. gingivalis-infected mice reduced bone loss to the same level as the uninfected control.

Microbiological basis for periodontal therapy

The search for the etiologic agents of periodontal diseases started in the Golden Era of medical bacteriology, when the etiologic agents of many bacterial infections were isolated and characterized. After the initial enthusiasm in establishing the infectious nature and the true agents of periodontal diseases, this concept was virtually ignored for the next four decades. Until the early 1970s treatment regimens based on the non-specific plaque hypothesis were directed towards a non-specific reduction in plaque amount. Later, the specific plaque hypothesis established the role of some microorganisms such as A. actinomycetemcomitans, P. gingivalis, T. forsythensis, T. denticola, P. intermedia and F. nucleatum in different forms of periodontal diseases. It was recently suggested that these suspected periodontal pathogens seem to not act alone and interactions between species, especially the balance between pathogenic and beneficial species affect both progression of disease and response of tissues to periodontal therapy. Nowadays it is well established that one of the goals of therapy is to control such periodontal pathogens. Among the most commonly used therapies to treat periodontal infections are scaling and root planing (SRP), supragingival plaque control and periodontal surgeries. Many studies confirmed the reduction of "red complex" species by SRP, and apically repositioned flap can lead to an additional beneficial effect in the subgingival microbiota by decreasing levels of "red" and "orange complexes" species. Furthermore, the level of plaque control maintained by the patients has been considered a crucial step in preventing recurrence of destructive periodontitis.

Porphyromonas gingivalis: an invasive and evasive opportunistic oral pathogen

Porphyromonas gingivalis is a Gram-negative oral anaerobe that is involved in the pathogenesis of periodontitis, an inflammatory disease that destroys the tissues supporting the tooth, eventually leading to tooth loss. Porphyromonas gingivalis has can locally invade periodontal tissues and evade the host defence mechanisms. In doing so, it utilizes a panel of virulence factors that cause deregulation of the innate immune and inflammatory responses. The present review discusses the invasive and evasive strategies of P. gingivalis and the role of its major virulence factors in these, namely lipopolysaccharide, capsule, gingipains and fimbriae. Moreover, the role of P. gingivalis as a 'keystone' biofilm species in orchestrating a host response, is highlighted.

Denaturing gradient gel electrophoresis analysis with different primers of subgingival bacterial communities under mechanical debridement

DGGE of 16S rDNA is one of the most frequently used methods to study microbial communities. In this study, the DGGE profiles of different 16S rDNA regions of the periodontal pathogens Porphyromonas gingivalis, Fusobacterium nucleatum, and Prevotella nigrescens were investigated. The results suggested that V3-V5 and V6-V8 fragments may be suitable for community analysis of subgingival bacteria. Further analysis of subgingival samples with V3-V5 and V6-V8 regions as target fragments suggested that, in chronic periodontitis, re-colonization by periodontal bacteria with a population very similar to the baseline may occur by 6 weeks after mechanical debridement.

Feasibility and therapeutic strategies of vaccines against Porphyromonas gingivalis

Periodontitis is a chronic infectious disease that is highly prevalent worldwide and is characterized by inflammation of the gums, and loss of connective tissue and bone support. The Gram-negative anerobic bacterium Porphyromonas gingivalis is generally accepted as the main etiological agent for chronic periodontitis. The objective of this paper is to elucidate the feasibility of achieving protection against periodontitis though immunization against P. gingivalis. Until now, animal studies have showed no complete protection against P. gingivalis. However, current knowledge about P. gingivalis structures could be applicable for further research to develop a successful licensed vaccine and alternative therapeutic strategies. This review reveals that a multicomponent vaccine against P. gingivalis, which includes structures shared among P. gingivalis serotypes, will be feasible to induce broad and complete protection.

Comparison of periodontal pathogens between cats and their owners

The periodontal pathogens Porphyromonas gingivalis and Tannerella forsythia are strongly associated with periodontal disease and are highly prevalent in humans with periodontitis. Porphyromonas and Tannerella spp. have also been isolated from the oral cavity of cats. The oral microflora in animals was compared with those in humans in earlier studies, but no studies are available on the comparison of the oral microflora from pets and their respective owners. The aim of this study was to determine the presence of these bacteria in the oral microflora of cats and their owners, since animal to human transmission, or vice versa, of oral pathogens could have public health implications. This study investigated the prevalence of Porphyromonas gulae, P. gingivalis, and T. forsythia in the oral microflora of cats and their owners, using culture and polymerase chain reaction (PCR). All Porphyromonas isolates from cats (n=64) were catalase positive, whereas the Porphyromonas isolates from owners (n=7) were catalase negative, suggesting that the isolates from cats were P. gulae whereas those from the owners were P. gingivalis. T. forsythia was recovered from both cats (n=63) and owners (n=31); the proportion of T. forsythia relative to the total CFU was higher in cats with periodontitis than in cats without periodontal disease. Genotyping of T. forsythia isolates (n=54) in six cat/owner couples showed that in one cat/owner couple the T. forsythia isolates (n=6) were identical. These T. forsythia isolates were all catalase positive, which led us to hypothesize that transmission from cats to owners had occurred and that cats may be a reservoir of T. forsythia.

Evaluation of two local drug delivery systems as adjuncts to mechanotherapy as compared to mechanotherapy alone in management of chronic periodontitis: A clinical, microbiological, and molecular study

BACKGROUND

Modern concepts of treating inflammatory periodontal disease aim at changes in the subgingival ecosystems within the periodontal pockets to alter the complex microbial community into a microbiota compatible with good periodontal health. Systemic antimicrobial therapy, although effective, involves a relatively high dose with repeated intakes over a prolonged period of time to achieve the required inhibitory concentrations in the sulcular fluid. The adjunctive use of local drug delivery may provide a beneficial response, especially in specific areas where conventional forms of therapy might fail. The aim of this study was to compare the efficacy of two local drug delivery systems, one containing metronidazole and the other containing tetracycline hydrochloride as adjuncts to mechanotherapy in the treatment of chronic periodontitis.

MATERIALS AND METHODS

There were three groups that were labeled as group A (Scaling + Tetracycline), group B (Scaling + Metronidazole), and group C (Scaling alone). A microbiological analysis was carried out to determine the efficacy of these systems in changing the pathogenic flora in deep pockets. In addition, a multiplex polymerase chain reaction was carried out to confirm the presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis (Pg), and Tannerella forsythensis in the flora associated with chronic periodontitis.

RESULTS

There was clinical improvement in groups A and B, which correlated with an improvement in the microbiological parameters; these results were sustained for 90 days following therapy. In Group C, the flora showed a shift towards baseline at the end of 90 days.

CONCLUSIONS

According to this study, both the local antibiotic therapies resulted in greater improvement in microbiological parameters when used as an adjunct to mechanotherapy as compared to mechanotherapy alone.

Relationship between the presence of periodontopathic bacteria and the expression of chemokine receptor mRNA in inflamed gingival tissues

BACKGROUND AND OBJECTIVE

Periodontal disease is a chronic disease characterized by the interaction between periodontopathic bacteria and the host immune response. The aim of this study was to investigate the correlation between periodontopathic bacteria and host immune cell infiltrates.

MATERIAL AND METHODS

Twenty-two patients with chronic periodontitis were included in this study. Gingival tissues were taken at the periodontal surgery after completion of initial therapy. Three types of periodontopathic bacteria were detected by polymerase chain reaction, and the prevalence of mRNA expression of chemokine receptors was examined by reverse-transcription-polymerase chain reaction in the gingival tissues. The infiltration of T and B cells was determined by an immunohistochemical method.

RESULTS

In the patients, both Porphyromonas gingivalis and Tanerella forsythia were detected, and the mRNA expression of chemokine receptors CXCR1&2, CXCR4, CCR1, CCR2, CCR3 and CCR4 were more prevalent. The mean number of infiltrated B cells was significantly larger than that of T cells in the sites harboring both P. gingivalis and T. forsythia. Similarly, in the sites where P. gingivalis was detected but T. forsythia was not, the mean number of B cells was significantly larger than that of T cells. In the sites with mRNA expression of CCR2 and CCR3, the mean number of B cells was significantly larger.

CONCLUSION

These results suggest that a high proportion of T helper 2-associated chemokine receptor-positive T cells may be associated with the predominance of B cells and may play an important role in the formation of chronic periodontitis in sites where both P. gingivalis and T. forsythia are detected.

Association of Eubacterium nodatum and Treponema denticola with human periodontitis lesions

BACKGROUND

The purpose of the present investigation was to compare the levels, proportions and percentage of sites colonized by 40 bacterial species in subgingival plaque samples from periodontally healthy subjects and patients with chronic periodontitis to seek possible pathogens other than the consensus pathogens Porphyromonas gingivalis and Tannerella forsythia.

METHOD

Subgingival plaque samples were taken from the mesial aspect of each tooth in 635 subjects with chronic periodontitis and 189 periodontally healthy subjects. The samples were individually analyzed for their content of 40 bacterial species using checkerboard DNA-DNA hybridization (total samples = 21,832). Mean counts, % DNA probe counts and percentage of sites colonized at >10(5) were determined for each species in each subject and then averaged in each clinical group. Significance of difference between groups was determined using the Mann-Whitney test. Association between combinations of species and periodontal status was examined by stepwise logistic regression analysis. Analyses were repeated using a subset of subjects from both clinical groups who had proportions of P. gingivalis plus T. forsythia less than the median (4.42%) found in periodontally healthy subjects. All analyses were adjusted for multiple comparisons.

RESULTS

For the 824 subjects the consensus pathogens P. gingivalis and T. forsythia as well as Eubacterium nodatum and Treponema denticola had significantly higher mean counts, proportions and percentage of sites colonized in samples from subjects with periodontitis than from periodontally healthy subjects. There were significantly more Capnocytophaga gingivalis, Streptococcus gordonii and Veillonella parvula in periodontally healthy subjects. E. nodatum, T. denticola, Streptococcus oralis, Streptococcus intermedius, Fusobacterium nucleatum ssp. vincentii all had higher counts and proportions in diseased than healthy subjects who had low proportions of P. gingivalis and T. forsythia. Logistic regression analysis indicated that the same species groups were associated with disease status after adjusting for the proportions of the other species.

CONCLUSIONS

This investigation confirmed the strong association of P. gingivalis and T. forsythia with chronic periodontitis and emphasized a strong association of E. nodatum and T. denticola with periodontitis whether in the presence or absence of high levels of the consensus pathogens. Other species, including S. oralis, Eikenella corrodens, S. intermedius and F. nucleatum ssp. vincentii, were associated with disease when P. gingivalis and T. forsythia were present in low proportions.

Risk ofPorphyromonas gingivalisRecolonization During the Early Period of Periodontal Maintenance in Initially Severe Periodontitis Sites

BACKGROUND

Porphyromonas gingivalis is considered a critical pathogen of periodontal diseases including recurrent periodontitis. The profound effects of active periodontal treatment (APT) on P. gingivalis elimination were previously demonstrated and revealed that the subsequent P. gingivalis-free or -suppressed status seems to be maintained during early periodontal maintenance (PMT). The aim of the present study was to show the occurrence of microbial recolonization during this early PMT period.

METHODS

In total, 128 sites from 11 generalized chronic periodontitis patients and one generalized aggressive periodontitis patient underwent clinical and microbiologic examination at baseline (Exam-I), after APT (Exam-II), and in PMT (Exam-III). Exam-III was carried out an average of 4.5 +/- 3.5 months after Exam-II. Detection and quantification of putative pathogens were performed using a polymerase chain reaction-based method.

RESULTS

The PMT used was effective in maintaining the clinical conditions improved by APT. However, in microbiological examinations, Exam-III showed higher detection frequency and levels of P. gingivalis than Exam-II. This suggests that a P. gingivalis recolonization started in the early PMT period. P. gingivalis-increased sites then showed significantly more severe signs of periodontitis in Exam-I than P. gingivalis-stable sites (bleeding on probing frequency: 76.7% versus 56.5%; suppuration frequency: 41.9% versus 12.9%). On the other hand, in Exam-II, no significant differences of clinical parameters were noted between P. gingivalis-increased and -stable sites.

CONCLUSION

Severe periodontitis sites before APT seemed to place them at risk of P. gingivalis recolonization in the early PMT period, and this microbial restoration could be a cause of recurrent periodontitis.

prtHinTannerella forsythensisIs Not Associated With Periodontitis

BACKGROUND

It has been suggested that prtH in Tannerella forsythensis encodes for a cystein proteinase that is associated with its pathogenic potential and can discriminate between periodontal health and disease. The aim of this investigation was to further establish this potentially important observation.

METHODS

A group of 33 consecutive adult patients with periodontitis (mean age: 47.6 +/- 10.1 years) harboring T. forsythensis was selected to investigate the presence of prtH by polymerase chain reaction (PCR). The T. forsythensis strains were isolated by anaerobic culture techniques. To investigate the association of this gene with periodontitis, a group of 14 age-matched subjects (mean age: 56.4 +/- 6.9 years) without any signs of periodontal disease (probing depths <3 mm and no radiographic attachment loss) was tested for comparison. Pure isolates and crude subgingival plaque samples were used as a template for the PCR.

RESULTS

In the group of 33 T. forsythensis-positive patients, we found two T. forsythensis isolates to be prtH negative. Despite repeated analyses, testing of the whole subgingival plaque samples revealed only 17 of 33 samples to be prtH positive. The T. forsythensis isolates from the 14 periodontally healthy subjects were all prtH positive. The odds ratio of the presence of prtH in T. forsythensis in periodontitis patients versus healthy controls is 1.06 (P >0.05).

CONCLUSIONS

On the basis of our data, we conclude that the presence of prtH in T. forsythensis is not discriminative for patients with T. forsythensis-associated periodontitis compared to healthy carriers of T. forsythensis. In addition, the use of whole subgingival plaque samples to test for the prevalence of prtH in bacteria appeared unreliable. Culture of the microorganism is an important condition to receive a sufficient amount of template DNA to detect the specific locus of the genome.

Involvement ofPorphyromonas gingivalis fimAGenotype in Treatment Outcome Following Non-Surgical Periodontal Therapy

BACKGROUND

Porphyromonas gingivalis is considered a critical pathogen in periodontal diseases. It is classified into six genotypes based on diversity of the fimA gene encoding fimbrillin. The present study evaluated the involvement of the fimA genotype in treatment outcome following non-surgical periodontal therapy.

METHODS

Chronic periodontitis patients were enrolled in this study; all received clinical and microbiological examinations at baseline. The detection of subgingival species and identification of P. gingivalis fimA genotypes were performed using polymerase chain reaction based methods. In total, 160 P. gingivalis positive sites with bleeding on probing (BOP) and a probing depth of > or =4 mm were accepted. They were followed up after scaling and root planing.

RESULTS

Longitudinal investigation indicated that fimA type I positive sites at baseline were followed by a significantly higher frequency of persistent BOP after treatment than type I negative sites (51.6% versus 27.9%), while types Ib and II were not. Type I positive sites also showed more persistence of Tannerella forsythensis and P. gingivalis after treatment than type I negative sites. In post-treatment investigation, type I positive sites showed higher frequencies of BOP and T. forsythensis detection than type I negative sites (77.8% versus 43.5% and 100% versus 76.1%, respectively).

CONCLUSIONS

BOP in initially type I positive sites showed little improvement with treatment, and the combined persistence of fimA type I and T. forsythensis seemed to be involved in this poor treatment outcome. The present study demonstrated the potential of P. gingivalis fimA type I as a predictor of persistent BOP after treatment.

The prevalence and pathogenic differences of Porphyromonas gingivalis fimA genotypes in patients with aggressive periodontitis

BACKGROUND

The fimA gene, which encodes fimbrillin (FimA), is found in Porphyromonas gingivalis and has been classified into six genotypes based on nucleotide sequence. P. gingivalis that possesses the type II fimA gene is prevalent in adult periodontitis.

OBJECTIVES

The aim of this study was to investigate the prevalence of P. gingivalis fimA genotypes in Japanese aggressive periodontitis patients, and to examine their virulence.

METHODS

Subgingival plaque samples were obtained from 223 sites in 18 aggressive periodontitis patients and 95 sites in 22 periodontally healthy young adults. Actinobacillus actinomycetemcomitans, P. gingivalis and Tannerella forsythensis detection, determination of the fimA genotype in P. gingivalis, and the quantification of P. gingivalis were analyzed by polymerase chain reaction (PCR) methods. The proteolytic activities of the P. gingivalis fimA type I and fimA type II were also examined.

RESULTS

In aggressive periodontitis patients, the most prevalent fimA genotype was the type II (46.7%), followed by the type Ib and type I, whereas in healthy subjects, the type I fimA was the only genotype detected. The number of P. gingivalis pathogens was the greatest in the type I fimA positive sites, and the frequency of coexisting A. actinomycetemcomitans and T. forsythensis was highest in the type II fimA positive sites in the aggressive periodontitis patients. Both the arginine-specific cysteine proteinase (Arg-gingipain) and lysine-specific cysteine proteinase (Lys-gingipain) activity of the P. gingivalis fimA type I strain were significantly higher than those of the fimA type II strains.

CONCLUSIONS

These results suggest that differences in virulence exist among different fimA genotypes. Coadherence with other pathogens in P. gingivalis fimA type II-associated aggressive periodontitis and quantitative increases in P. gingivalis in fimA type I-associated aggressive periodontitis are related to this virulence.

Quantitative real-time polymerase chain reaction based on single copy gene sequence for detection of periodontal pathogens

OBJECTIVE

To develop a method for quantification of Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg) and Tannerella forsythensis (Tf) from subgingival plaque samples based on TaqMan real-time polymerase chain reaction (PCR) technology.

MATERIAL AND METHODS

Bacterial cells from these species were obtained after culturing reference strains and were counted microscopically. Cellular suspensions in Tris-EDTA buffer were used for DNA extraction after boiling for 20 min. Primers for PCR were selected from sequences of the LktC (Aa), Arg-gingipain (Pg) and BspA antigen (Tf) genes in order to yield amplicons below 100 bp. TaqMan-based real-time PCR was adjusted to quantify each species separately. Cycle threshold (C(T)) values were calculated for each species according to the initial number of copies. A reliability analysis was carried out using intra-class correlation coefficients (ICCs) with a two-way random effects model.

RESULTS

A high sensitivity and specificity was obtained for the detection of the three bacterial species. The TaqMan real-time PCR technology yielded a good repeatability in the obtained cycle threshold (C(T)) values for each initial number of copies, demonstrating coefficients of variation below 5% for each bacteria. The reproducibility of the technique was also demonstrated by the high ICCs (>0.98; p<0.00001) obtained for each bacteria with and without the addition of subgingival plaque.

CONCLUSION

A novel diagnostic method based on TaqMan real-time PCR was developed for the quantification of Aa, Pg and Tf. It has demonstrated good sensitivity and repeatability on pure cultures. Its diagnostic utility should be demonstrated in subgingival plaque samples.

Clinical effects of scaling and root planing on untreated teeth

OBJECTIVE

The aim of this report is to examine whether scaling and root planing (SRP) in one area of the mouth may affect periodontal improvement in untreated areas in the same patient, possibly through systemic effects of treatment.

MATERIAL AND METHODS

Twenty patients diagnosed with generalized aggressive periodontitis were randomized into treatment (n=11) and no treatment (n=9) groups. Within the treatment group, three quadrants were treated by SRP at week 0, 3, 12, and 24, while a single experimental quadrant remained untreated throughout the study. The outcome for all teeth was assessed using clinical parameters, subtraction radiography, and pathogenic bacteria levels in the subgingival flora over the 24-week study period.

RESULTS

Compared with sites in no treatment patients, the treated sites in the treated patients showed a 1 mm decrease in probing depth (PD) (p<0.01) and a 0.5 mm increase in bone height (p<0.01) by 24 weeks. In untreated sites within treated subjects, however, PDs tended to improve (p=0.09) but at a reduced rate compared with treated sites. The levels of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythensis (Bacteroides forsythus) remained unchanged in untreated sites while levels of Prevetolla intermedia and Treponema denticola tended to decrease as compared with controls but did not reach significance.

CONCLUSIONS

This study indicates that untreated sites in treated periodontitis patients show a trend towards clinical improvement and exhibit reductions in some but not all periodontopathic bacterial species tested.

Epidural abscess and osteomyelitis due to Actinobacillus actinomycetemcomitans

Actinobacillus actinomycetemcomitans is a microaerophilic, fastidious Gram-negative rod that most commonly causes periodontitis and odontogenic infections. We report the first case of an epidural abscess and osteomyelitis due to this organism resulting from self-extraction of carious teeth. The patient responded to surgical debridement and prolonged antimicrobial therapy with intravenous ceftriaxone.

Methods of detection of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythensis in periodontal microbiology, with special emphasis on advanced molecular techniques: a review

BACKGROUND

Certain specific bacterial species from the subgingival biofilm have demonstrated aetiological relevance in the initiation and progression of periodontitis. Among all the bacteria studied, three have shown the highest association with destructive periodontal diseases: Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg) and Tannerella forsythensis (Tf). Therefore, the relevance of having accurate microbiological diagnostic techniques for their identification and quantification is clearly justified.

AIM

To evaluate critically all scientific information on the currently available microbial diagnostic techniques aimed for the identification and quantification of Aa, Pg and Tf.

SUMMARY

Bacterial culturing has been the reference diagnostic technique for many years and, in fact, most of our current knowledge on periodontal microbiology derives from cultural data. However, the advent of new microbial diagnostics, mostly based on immune and molecular technologies, has not only highlighted some of the shortcomings of cultural techniques but has also allowed their introduction as easy and available adjunct diagnostic tools to be used in clinical research and practice. These technologies, mostly polymerase chain reaction (PCR), represent a field of continuous development; however, we still lack the ideal diagnostic to study the subgingival microflora. Qualitative PCR is still hampered by the limited information provided. Quantitative PCR is still in development; however, the promising early results reported are still hampered by the high cost and the equipment necessary for the processing.

CONCLUSION

Quantitative PCR technology may have a major role in the near future as an adjunctive diagnostic tool in both epidemiological and clinical studies in periodontology. However, culture techniques still hold some inherent capabilities, which makes this diagnostic tool the current reference standard in periodontal microbiology.

Quantitative real-time polymerase chain reaction versus culture: a comparison between two methods for the detection and quantification of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythensis in subgingival plaque samples

OBJECTIVE

The purpose of this investigation was to validate a real-time quantitative polymerase chain reaction (PCR) assay in identifying and quantifying Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythensis from subgingival plaque samples taken from subjects with different periodontal conditions, when compared with conventional cultural procedures.

PATIENTS AND METHODS

Ninety-two adult subjects participated in this study, 32 with periodontitis, 30 with gingivitis and 30 healthy. A pooled subgingival sample was obtained from every patient. Culturing procedures were carried out using standard techniques. For real-time PCR analysis, primers were selected from sequences of the LktC (A. actinomycetemcomitans), Arg-gingipain (P. gingivalis) and BspA antigen (T. forsythensis) genes. Contingency tables were constructed to compare the qualitative results, while quantitative data were evaluated by paired t-test.

RESULTS

A. actinomycetemcomitans was the least frequently recovered species with both techniques. Prevalence of P. gingivalis was low in healthy patients, increased in gingivitis and peaked in periodontitis patients. The frequency of detection of T. forsythensis showed marked differences between culture and PCR, although the same tendency of an increase in prevalence from health to gingivitis and to periodontitis was observed with both methods. Contingency tables demonstrated a good level of agreement between PCR and culture procedures for A. actinomycetemcomitans and P. gingivalis, especially in periodontitis patients. P. gingivalis culture counts were significantly higher than those obtained by PCR. The opposite was true for T. forsythensis, and statistically significant higher counts were obtained by PCR for gingivitis and periodontitis patients.

CONCLUSION

This study demonstrated a good agreement between the quantitative PCR technology and the culture procedure. The high sensitivity and specificity of the quantitative PCR technology justify its use in epidemiological studies and as an adjunct in clinical diagnosis of periodontal patients.

Microbial Identification in the Management of Periodontal Diseases. A Systematic Review

BACKGROUND

Our understanding of the complexity of the oral microbiota continues to improve as new technologies, such as the analysis of 16S rRNA bacterial genes, are utilized. Despite the difficult of cataloguing all microorganisms and determining their pathogenic potential, some species, mostly members of the resident oral microbiota, have been identified as likely periodontal pathogens. However, for microbial diagnosis to be of value, it needs to affect disease diagnosis and/or treatment planning as well as result in superior treatment outcomes and/or provide an economic benefit to the patient.

RATIONALE

The purposes of this systematic review were to determine if microbial identification influences periodontal patient management and whether treatment outcomes are better compared to patients whose treatment plans are developed without this information.

FOCUSED QUESTION

In patients with periodontal diseases, does microbial identification influence patient management compared to treatment prescribed without this information?

SEARCH PROTOCOL

The MEDLINE database was searched for clinical studies in English from 1991 through 2002 by 2 investigators. Hand searches were performed on the Journal of Clinical Periodontology, Journal of Periodontology, Journal of Periodontal Research, Oral Microbiology and Immunology, and Periodontology 2000. In addition, directors of diagnostic laboratories were contacted about unpublished data.

SELECTION CRITERIA

INCLUSION CRITERIA

Articles in which bacterial identification influenced patient treatment were preferred as were those reporting longitudinal data demonstrating a direct relationship between the presence or absence of certain bacteria and subsequent alterations in clinical variables. Because of the limited number of studies, all articles, including case reports, were considered.

EXCLUSION CRITERIA

Review articles without original data were excluded, although references were examined for possible inclusion. Articles reporting data showing associations between certain microorganisms and disease or health that did not affect treatment were excluded. Clinical trials testing antibacterial agents for their ability to enhance mechanical debridement were not included since bacterial identification had little effect on drug selection or experimental group assignment. Articles dealing with implants rather than natural teeth were omitted. DATA ANALYSIS AND COLLECTION: The heterogeneity of the published data precludes any meaningful pooling of data or meta-analysis. The pertinent literature, including relevant variables of plaque, gingivitis, and bleeding on probing scores; probing depth; clinical attachment level; number of lost teeth; and microbial changes; and patient-centered outcomes including decrease in morbidity, reduced need for surgery, and duration and cost of treatment are summarized.

MAIN RESULTS

1. There was a lack of articles with a high evidence rating; most pertinent articles were either case reports or case series without controls. 2. Because reports were heterogeneous regarding study design, patient selection, and data collection, meta-analysis was not feasible and results are summarized in tabular format. 3. This report is based on a total of 24 studies, representing a total patient population of approximately 835. 4. Thirteen studies reported on microbiological identification as an aid in treatment planning. 5. Eleven studies reported a differential clinical response depending on the detection or lack of detection of specific organisms.

REVIEWERS' CONCLUSIONS

1. The published material suggests that microbiological monitoring may be useful in management of selected patients who do not respond to standard therapy. 2. Some practitioners consider microbial identification a valuable adjunct to managing patients with certain forms of periodontitis, although there is a lack of strong evidence to this effect. 3. Additional research is needed to address this issue.