Natural history of periodontitis: Disease progression and tooth loss over 40 years.

OBJECTIVES: To assess long-term attachment and periodontitis-related tooth loss (PTL) in untreated periodontal disease over 40 years. MATERIAL AND METHODS: Data originated from the natural history of periodontitis study in Sri Lankan tea labourers first examined in 1970. In 2010, 75 subjects (15.6%) of the original cohort were re-examined. RESULTS: PTL over 40 years varied between 0 and 28 teeth (mean 13.1). Four subjects presented with no PTL, while 12 were edentulous. Logistic regression revealed attachment loss as a statistically significant covariate for PTL (p < .004). Markov chain analysis showed that smoking and calculus were associated with disease initiation and that calculus, plaque, and gingivitis were associated with loss of attachment and progression to advanced disease. Mean attachment loss <1.81 mm at the age of 30 yielded highest sensitivity and specificity (0.71) to allocate subjects into a cohort with a dentition of at least 20 teeth at 60 years of age. CONCLUSIONS: These results highlight the importance of treating early periodontitis along with smoking cessation, in those under 30 years of age. They further show that calculus removal, plaque control, and the control of gingivitis are essential in preventing disease progression, further loss of attachment and ultimately tooth loss.

Risk factors that may modify the innate and adaptive immune responses in periodontal diseases.

Plaque-induced periodontal diseases occur in response to the accumulation of dental plaque. Disease manifestation and progression is determined by the nature of the immune response to the bacterial complexes in plaque. In general, predisposing factors for these periodontal diseases can be defined as those factors which retain or hinder the removal of plaque and, depending upon the nature of the immune response to this plaque, the disease will either remain stable and not progress or it may progress and result in chronic periodontitis. In contrast, modifying factors can be defined as those factors that alter the nature or course of the inflammatory lesion. These factors do not cause the disease but rather modify the chronic inflammatory response, which, in turn, is determined by the nature of the innate and adaptive immune responses and the local cytokine and inflammatory mediator networks. Chronic inflammation is characterized by vascular, cellular and repair responses within the tissues. This paper will focus on how common modifying factors, such as smoking, stress, hormonal changes, diabetes, metabolic syndrome and HIV/AIDS, influence each of these responses, together with treatment implications. As treatment planning in periodontics requires an understanding of the etiology and pathogenesis of the disease, it is important for all modifying factors to be taken into account. For some of these, such as smoking, stress and diabetic control, supportive health behavior advice within the dental setting should be an integral component for overall patient management.

Analysis of P. gingivalis, T. forsythia and S. aureus levels in edentulous mouths prior to and 6 months after placement of one-piece zirconia and titanium implants.

BACKGROUND: It has been suggested that completely edentulous patients harbour fewer periodontopathic bacteria compared with dentate patients, due to the removal of the subgingival periodontal environment. However, reappearance of certain microbes has been reported after the placement of implants in these patients. AIM: The aim of this study was to determine whether the periodontopathic bacteria Porphyromonas gingivalis and Tannerella forsythia, as well as the non-periodontopathic bacterium, Staphylococcus aureus, emerged in edentulous patients 6 months after placement of one-piece zirconia and titanium implants. MATERIALS AND METHODS: Twenty-six patients were included in the study (titanium = 13, zirconia = 13). Microbial samples were collected from the tongue prior to implant placement and 6 months after implant placement from both the tongue and from around the implants. A qRT-PCR assay using SYBR green/ROX chemistry was used for the detection and quantification of rgp, nuc and karilysin single-copy gene of P. gingivalis, T. forsythia and S. aureus, respectively. Positive controls used in the study were pure bacterial gDNA purified from cultures of P. gingivalis and S. aureus, a cloned sequence of the karilysin gene for T. forsythia, a plaque sample positive for P. gingivalis and T. forsythia, and nasal gDNA for S. aureus. RESULTS: The results show that prior to implant placement, all three bacterial species were below the lower limit of quantification in all edentulous patients. The samples collected from the tongue and around the implants remained below the lower limit of quantification for each of the three species. However, all positive controls used in the study were detectable in the samples. qPCR standard curves showed correlation coefficients >0.97 and efficiencies >94.5% (slope range -3.19 to -3.46) for each of the SYBR green PCR assays. CONCLUSION: The results of this study indicate that the tested organisms did not emerge 6 months after implant placement irrespective of the nature of the implant biomaterial. A further follow-up of at least 2 years post-implantation of these patients is suggested to determine whether there are any changes in the oral microbiota and whether such changes are associated with the development of peri-implant disease.

Periodontal disease and systemic illness: will the evidence ever be enough?

The concept of focal infection or systemic disease arising from infection of the teeth was generally accepted until the mid-20th century when it was dismissed because of lack of evidence. Subsequently, a largely silo approach was taken by the dental and medical professions. Over the past 20 years, however, a plethora of epidemiological, mechanistic and treatment studies have highlighted that this silo approach to oral and systemic diseases can no longer be sustained. While a number of systemic diseases have been linked to oral diseases, the weight of evidence from numerous studies conducted over this period, together with several systematic reviews and meta-analyses, supports an association between periodontitis and cardiovascular disease, and between periodontitis and diabetes. The association has also been supported by a number of biologically plausible mechanisms, including direct infection, systemic inflammation and molecular mimicry. Treatment studies have shown that periodontal treatment may have a small, but significant, systemic effect both on endothelial function and on glycemic control. Despite this, however, there is no direct evidence that periodontal treatment affects either cardiovascular or diabetic events. Nevertheless, over the past 20 years we have learnt that the mouth is an integral part of the body and that the medical and dental professions need to work more closely together in the provision of overall health care for all patients.

Immediate single implant restorations in mandibular molar extraction sockets: a controlled clinical trial.

BACKGROUND: In the replacement of missing teeth, a paradigm shift is currently observed with immediate implant placement and/or restoration, particularly in the aesthetic zone. In molar sites, however, anatomical, occlusal and biomechanical considerations remain deterrent factors influencing the outcome of this treatment paradigm. The aim of this report was to evaluate immediate placement and immediate restoration of strongly tapered wide-diameter implant in fresh mandibular molar extraction sockets. METHODS: Twenty-four 8- or 9-mm diameter implants were placed in either a fresh molar extraction socket or a healed site. All the implants received provisional crowns within 48 h. The provisional crowns were replaced with full ceramic crowns after 8 weeks of implant placement. RESULTS: The overall implant success rate after 1 year of service for the 24 implants in two treatment groups was 75%. Success rates were 83.3% and 66.7% for the delayed and immediate placement groups respectively, with no significant difference observed between the two groups (P = 0.35). Implant stability measurements identified the immediately placed implants to be more stable immediately after surgery than delayed placed implants. In contrast, the delayed placed implants were more stable after 8 week healing time. CONCLUSIONS: The rehabilitation of single missing mandibular molars by immediately placed and restored wide-diameter implants was associated with a relatively high failure rate.

Periodontitis among adult populations in the Arab World.

BACKGROUND: The Arab World consists of 22 countries from North and North-east Africa and the Middle East. Periodontal disease is an important global oral health burden, and is highly prevalent in developing countries. OBJECTIVES: The objective of this narrative review is to report on the recorded prevalence of periodontitis in the Arab World, and to examine the methods used in collecting the data. DATA AND SOURCES: A search of the literature was performed using the PubMed database up to September 2011 to identify articles that reported on the prevalence of periodontal disease in the 22 Arab countries. Reports kept in the World Health Organization (WHO) Global Health Data bank were also used in this review. CONCLUSION: There is a paucity of up-to-date data regarding the prevalence of periodontitis in the Arab adult population. Most relevant data are at least 10 years old. From the literature available, it is clear that there is a need for epidemiological data that are representative of the adult population from this region. Such data will enable proper development of guidelines, allocation of resources and the development of appropriate public health programmes.

Oral hygiene behaviours and readiness to change using the TransTheoretical Model (TTM).

OBJECTIVE: The aim of this pilot study was to investigate the Transtheoretical Model (TTM) in relation to measures of readiness to change oral hygiene behaviours. RESEARCH DESIGN: Participants (N = 105) were recruited from a dental hygiene patient waiting list. A self-administered questionnaire was designed; it included four measures related to inter-dental cleaning used for TTM staging, confidence and frequency measures of future interdental cleaning and toothbrushing, together with items seeking demographic details. Data collection occurred before a dental hygiene appointment where oral health advice was offered, and then at three and six months afterwards, in order to measure readiness to change post-intervention. RESULTS: All three questionnaires were returned by 91.4% of participants. The confidence measures for maintaining toothbrushing twice per day and for interdental cleaning were associated with TTM staging at baseline (respective correlation coefficients of 0.200; P = 0.042 and 0.584; P < 0.001). Participants were likely to be in a higher TTM stage at 3 months after attendance at the dental hygiene clinic and then decline to a lower TTM stage by 6 months (baseline to 3 months and 6 months: Wilcoxon signed rank tests of p= 0.024 and p = 0.627). Of the 31 participants (33%) who improved their TTM staging between baseline and 3 months, 11 (35%) fell back to a lower category between 3 months and 6 months, 14 (45%) maintained their improvement, and 6 (19%) improved further. CONCLUSIONS: Understanding a person's readiness to change could improve the way in which oral hygiene interventions and advice are given in the clinical setting. The TTM staging measurement tool used here provides insight into people's readiness to change their oral hygiene behaviours, and its use would aid practitioners in the delivery of oral health messages. The initial improvement in TTM stage and subsequent regression was consistent with the TTM's relapse phenomenon and reinforces the concept that on-going support is crucial to maintaining behaviour change.

A comparison of Er:YAG laser and mechanical debridement for the non-surgical treatment of chronic periodontitis: a randomized, prospective clinical study.

AIMS: To compare a monotherapy of Er:YAG laser debridement (ERL), wavelength 2940 nm, with mechanical scaling and root planing (SRP) for the treatment of chronic periodontitis using clinical and patient-centred outcomes. METHODS: Twenty-eight participants had two randomly assigned quadrants treated with ERL and two with SRP. Full-mouth plaque index, probing depth, bleeding on probing, clinical attachment level and gingival recession were recorded at baseline and 6- and 12-weeks post therapy. A questionnaire was used to assess pain, discomfort and satisfaction during and after treatment. RESULTS: Twenty-two participants completed treatment and had 6- and 12-week clinical re-evaluations. SRP provided greater mean pocket depth reduction at 6- and 12-weeks (p = 0.01 and p = 0.003 respectively), and a greater reduction in pockets ≥ 4 mm at 6 weeks only (p = 0.03) compared with ERL. SRP also resulted in a significant reduction in bleeding on probing (BOP) sites at 12 weeks compared with ERL and a statistically significant greater reduction in mean clinical attachment level (CAL) at 6- (p = 0.02) and 12-weeks (p = 0.03). Patients expressed greater satisfaction with SRP on the day of treatment but were equally satisfied subsequently. CONCLUSION: SRP resulted in a statistically significant greater short-term improvement in clinical parameters and patient satisfaction compared with ERL.

Periodontal pathogen load and increased antibody response to heat shock protein 60 in patients with cardiovascular disease.

AIM: To determine the relationship between periodontal pathogen load and anti-human heat shock protein 60 (hHSP60) antibodies in patients with established cardiovascular disease (CVD). MATERIALS AND METHODS: Participants were cardiovascular patients (n = 74) with a previous hospital admission for myocardial infarction. Concurrent periodontal pathogen load of Porphyromonas gingivalis, Fusobacterium nucleatum, Tannerella forsythia and Aggregatibacter actinomycetemcomitans was determined using quantitative real-time PCR. Serum antibodies to these pathogens, GroEL and hHSP60 were determined using an ELISA. RESULTS: There was a trend for increasing anti-hHSP60 antibody as the number of bacterial species increased. The strongest positive correlations were found between anti-hHSP60 levels and numbers of T. forsythia (r = 0.43; p < 0.001) and between anti-hHSP60 and anti-GroEL levels (r = 0.39; p = 0.001). Patients with extensive periodontal pocketing (≥4 mm) had higher numbers of P. gingivalis and T. forsythia (p < 0.05) and a higher subgingival pathogen load (p < 0.05) than patients with minimal pocketing (≤1 site ≥ 4 mm). They also had significantly elevated anti-hHSP60 levels (p < 0.05). Overall, the highest anti-hHSP60 levels were seen in patients with extensive periodontal pocketing and all four bacterial species. CONCLUSIONS: In cardiovascular patients, a greater burden of subgingival infection with increased levels of P. gingivalis and T. forsythia is associated with modestly higher anti-hHSP60 levels.

Experiences and perceptions of oral health and oral health care among a sample of older New Zealanders.

BACKGROUND: Most research on older people's oral health has been quantitative. A need for more in-depth understanding of the oral health of that age group has pointed to a need for more qualitative investigations. OBJECTIVE: To explore experiences and perceptions of oral health and oral health care among an ethnically-mixed sample of older New Zealanders. METHODS: In-depth interviews were conducted with 24 older people in two communities in New Zealand's South Island. Thematic analysis of transcribed data was undertaken. RESULTS: Three main themes that emerged were: (1) the processes of negotiating a tension between cost and convenience of access; (2) the experiential constraining of oral health maintenance; and (3) trusting in dental professionals. These serve to organise processes such as normalising, justifying and social comparisons that create an equilibrium or tolerance and acceptance of what might otherwise be considered to be relatively poor oral health. CONCLUSIONS: We identified a number of shared experiences which affect older people's ability to maintain their oral health in the face of material and social barriers to oral health care. Because expectations were generally lower, there was greater concordance between experience and expectation, and people tended to be fairly satisfied with their oral health and the care they had received.

An exploratory study of the acceptability of delivering oral health information in community pharmacies.

OBJECTIVE: The community pharmacy is an accessible service which, with further training and support, could be used to deliver oral health messages. This is important especially for those with systemic diseases such as diabetes mellitus and cardiovascular disease, where the oral environment may have a negative impact. This qualitative study assessed the feasibility of pharmacists delivering oral health messages in community pharmacies. DESIGN AND METHODS: Semi-structured interviews were conducted with 49 pharmacists in Dunedin and Auckland, New Zealand, with a focus on the pharmacists' current knowledge, attitudes and possibilities for providing oral health information to patients with diabetes and cardiovascular disease. FINDINGS: There is potential for community pharmacists to provide oral health information to patients, dependent on the approach of the pharmacist and the patient response. The majority of pharmacists agreed that providing oral health advice was within their role; however, few did so proactively. They highlighted a lack of available resources relating to oral health and systemic disease. Further training relating to oral health and systemic disease would be necessary to provide the knowledge to support any resources. The preferred option by pharmacists for such training was an evening course or workshop.

Genome sequence of the bacteriocin-producing oral probiotic Streptococcus salivarius strain M18.

Streptococcus salivarius is a Gram-positive bacterial commensal and pioneer colonizer of the human oral cavity. Many strains produce ribosomally synthesized proteinaceous antibiotics (bacteriocins), and some strains have been developed for use as oral probiotics. Here, we present the draft genome sequence of the bacteriocin-producing oral probiotic S. salivarius strain M18.

Reduction of hsCRP levels following an Oral Health Education Program combined with routine dental treatment.

OBJECTIVES: The present study aimed to determine the effect of a personalised oral health education program, in combination with routine dental treatment, on serum biomarkers of systemic disease compared to dental treatment alone in a population from a low-socioeconomic community with poor oral health. METHODS: This secondary analysis of a randomised clinical trial involved 295 participants (mean age, 45.4 ± 11 years) assigned to two groups. One group received dental treatment combined with the Oral Health Education Program (OHEPDT), while the second group (DT) received dental care without the Education Program. Serum levels of high-sensitivity C-reactive protein (hsCRP), lipid profile (total cholesterol, triglycerides, and high- and low-density lipoprotein cholesterol), and HbA1c levels were analysed at baseline and after 12 months. Changes in diet, smoking and alcohol consumption were also determined. RESULTS: No intergroup differences were observed for the lipid profile and HbA1c levels. A reduction in the hsCRP levels at the 12-month follow-up was observed in the OHEPDT group, which was significantly different from the DT group (p = 0.01). Multivariate modelling indicated that baseline hsCRP levels (p = 0.000), baseline body mass index (p = 0.000), and higher consumption of vegetables (p = 0.021) predicted a reduction in hsCRP levels. CONCLUSIONS: This study demonstrated that personalised oral health education combined with routine dental treatment was associated with a significant reduction in hsCRP levels subsequent to dietary behavioural changes. These findings suggest that personalised oral health education in combined with routine dental treatment may have beneficial effects on general health. CLINICAL SIGNIFICANCE: The strategy for developing an oral health program that involves education of the modifiable common risk factors for general health has beneficial effects and should be one of the priority components of these programs to improve oral and general health, particularly for at-risk communities.

The Effect of a Personalized Oral Health Education Program on Periodontal Health in an At-Risk Population: A Randomized Controlled Trial.

While periodontal disease is associated with many risk factors, socioeconomically disadvantaged communities experience the highest disease burden. The aim of this study was to evaluate the effectiveness of a personalized oral health education program, in combination with routine dental treatment, in participants from a low socioeconomic community. We used a randomized, controlled, examiner-blinded clinical trial. A total of 579 participants (aged 18-60 years) were randomly grouped: the intervention group (n = 292) received a personalized oral health education program in combination with routine dental care and the control group (n = 287) received routine dental care. All participants were assessed for improvement in oral health care behaviors, dental plaque, and periodontal status at baseline, 12 months, and 24 months. We found a significant drop (p < 0.001) in the plaque indices, Periodontal Probing Depths (PPD) and Bleeding on Probing (BOP) between baseline and the 12-month follow-up for both groups. For BOP, the number of sites positive was significantly different between baseline and the 24-month follow-up (p = 0.037). No differences were found between the two groups for any evaluated clinical outcome. The personalized oral health education program used in the current study did not appear to add significant improvement to clinical outcomes of periodontal health compared with routine restorative dental care per se.

Comparison of the clinical features of chronic and aggressive periodontitis.

Overall, while most clinicians would agree that aggressive forms of periodontitis exist as clinical entities, the clinical distinction between chronic and aggressive periodontitis (especially generalized) is not clear cut. This may not be all that significant from a treatment perspective, in so far as individualized anti-infective therapies are effective for both forms of the disease. However, from a research perspective, it is essential that these diseases be clearly distinguished in order to gain a complete understanding of their etiology and pathogenesis. The relative lack of clinical inflammation often associated with the localized molar-and-incisor form of aggressive periodontitis has been commented on for almost 100 years, and it is generally accepted that this form of the disease is associated with a thin biofilm, at least in its early stages. In contrast, the presence of clinical inflammation in generalized aggressive periodontitis appears to be similar to that observed in chronic periodontitis, and in this situation age of onset and family history are important additional criteria for either diagnosis or classification. It is also generally recognized that chronic periodontitis may subsequently be superimposed on both localized and generalized forms of aggressive periodontitis. While this may have little bearing on the treatment of such cases, it could have an enormous impact on both the design and interpretation of research studies, whether basic science or clinical. This highlights the essential difference between a diagnosis and a classification, whereby a diagnosis is the clinician's best guess, leading on to a treatment plan, whereas a classification does not allow such flexibility, requiring non-overlapping case definitions for research purposes if the underlying etiology of these diseases is ever to be fully elucidated.

Immediate placement or immediate restoration/loading of single implants for molar tooth replacement: a systematic review and meta-analysis.

PURPOSE: This systematic review and meta-analysis assessed the survival of immediately placed single implants in fresh molar extraction sites and immediately restored/loaded single molar implants in healed molar sites. MATERIALS AND METHODS: A search of the main electronic databases, including the Cochrane Oral Health Group's Trials Register, was conducted up to November 1, 2008. The meta-analysis was prepared in accordance with the guidelines of the Academy of Osseointegration Workshop on the State of the Science on Implant Dentistry. The data were analyzed with statistical software. RESULTS: For immediately placed molar implants, nine studies describing 1,013 implants were included to support a survival rate of 99.0%. There were no significant differences between immediate and delayed loading/restoration in molar sites (relative risk of 0.30, 95% confidence interval 0.05 to 1.61; P = .16). For immediate restoration/loading of single implants in healed molar sites, seven studies with 188 single implants were identified. In this case, the implant survival rate was 97.9%, with no difference between immediate and delayed loading (relative risk of 3.0, 95% confidence interval: 0.33 to 27.16; P = .33). Favorable marginal bone level changes in the immediate loading group were detected at 12 months (mean difference of -0.31, 95% confidence interval: -0.53 to -0.096; P = .005). CONCLUSIONS: The protocols of immediate placement and immediate restoration/loading of single implants in mandibular molar regions showed encouraging results.

The clinical course of chronic periodontitis: V. Predictive factors in periodontal disease.

BACKGROUND: The factors associated with initial periodontitis are not well understood and cannot be identified by cross-sectional studies. AIM: To identify the factors associated with the initiation of chronic periodontitis using ante-dependence modelling. MATERIAL AND METHODS: A 26-year longitudinal study of the natural history of periodontitis served as the basis for the study. In 1969, 565 Norwegian men aged 16-34 years were surveyed. Subsequent surveys were performed in 1971, 1973, 1975, 1981, 1988 and finally in 1995, with 223 remaining subjects. Plaque (PlI), gingival (GI) and calculus indices (CI) and loss of attachment (LoA) were recorded. Ante-dependence modelling using a Markov chain enabled the results of this sequence of examinations to be analysed longitudinally, taking into account serial dependence, describing temporal changes in patients' levels of disease and allowing for both progression and regression between disease categories. RESULTS: With age, the rate of disease regression decreased. Increasing calculus accumulation and smoking increased the rate of disease progression, while increasing GI increased the rate of regression. CONCLUSIONS: Increased mean CI and smoking were significant predictive covariates for progression, while increased mean GI and younger age predicted regression of initial periodontitis.

Immediate restoration/loading of immediately placed single implants: is it an effective bimodal approach?

OBJECTIVE: To compare systematically the survival and radiographic marginal bone level changes of two immediate implant protocols in the aesthetic region; immediate single implant restoration/loading in extraction sockets (the bimodal approach) compared with the same in healed sites. MATERIAL AND METHODS: A literature search of electronic databases, Cochrane Oral Health Group's Trials Register, National Research Register, conference proceedings and abstracts was performed without language restriction up to 1 August 2008. Hand searching included several dental journals and authors were contacted for missing information. Controlled trials that compared immediate restoration/loading of single implants placed in extraction sites with those placed in healed sites were selected. The meta-analysis was prepared according to the guidelines of the Quality of Reporting of Meta-analyses statement. The data were analysed using RevMan version 5.0 software. A fixed effects model was chosen with standardized mean differences for continuous data, and risk ratios for dichotomous data with 95% confidence intervals. RESULTS: Ten studies with 629 implants were included. Immediate single implant restoration/loading in extraction sockets in the aesthetic zone was associated with significantly higher risk of implant failure (risk ratio of 3.62, 95% confidence interval 1.15-11.45, P=0.03). However, the bimodal approach showed favourable marginal bone changes after 1 year. CONCLUSION: The review and meta-analysis supported the potential advantages offered by this bimodal approach, but indicated a higher risk when compared with immediate restoration/loading in healed ridges. Further long-term, well-conducted, randomized-controlled studies are needed to confirm the validity of this treatment option.

Home or away? Differences between home- and clinic-based dental examinations for older people.

OBJECTIVE: To determine whether home-based and clinic-based dental examinations of older people are comparable. BACKGROUND: Despite a number of studies which have examined the concordance between different examiners or examination circumstances, none has directly compared an oral examination conducted at home with one conducted in an appropriate clinical setting. MATERIALS AND METHODS: Dentate participants (n = 61) aged between 65 and 74 years underwent two clinical examinations, one in a conventional dental clinic and the other in the person's home. Kappa statistics, intra-class correlation coefficients and 'Difference against mean' plots were used to determine the nature and extent of any bias. RESULTS: The summary estimates for missing teeth and dental caries were close, although the home-based examinations resulted in a lower estimate of the mean number of decayed teeth and of untreated coronal decay. The lowest reliability statistics were observed with respect to the prevalence of untreated coronal caries, filled root surfaces and root surface (Decayed or Filled Surfaces) DFS. The periodontitis prevalence estimates were closer, but the reliability statistics were relatively low. The extent of bleeding on probing was relatively under-estimated in the home-based examinations. 'Difference against mean' plots indicated that, overall, the clinic-based examinations detected more disease (although this was not observed for all clinical parameters which were measured). CONCLUSION: While clinic-based examinations will remain the preferred option, the potential loss of information associated with home-based examinations is unlikely to be great enough to preclude using them where required, although surveys with larger samples (and therefore more accurate estimates) should restrict their proportion of home-based examinations to no more than 10%. As they are less precise, surveys with samples of 300 or fewer can safely accommodate up to about one-third of their examinations being conducted in participants' homes.

Tannerella forsythensis prtH genotype and association with periodontal status.

BACKGROUND: The prtH gene of Tannerella forsythensis encodes for a cysteine protease possessing virulent properties. Subgingival colonization by T. forsythensis with this genotype has been suggested to be a discriminator between periodontal health and disease. This study examined the prevalence of T. forsythensis prtH genotype in subgingival plaque and its association with periodontal disease progression and current disease status. METHODS: Subjects harboring T. forsythensis in their subgingival plaque were identified using real-time polymerase chain reaction (PCR). The presence or absence of the prtH genotype was assessed by conventional PCR. Probing depths and relative attachment levels were also assessed. RESULTS: The prtH genotype was detected in 13 of 56 (23.2%) subjects harboring T. forsythensis in their subgingival plaque. Periodontal disease progression was defined as two or more sites with > or = 2 mm attachment loss in the previous 2-year period; current disease was defined as four or more sites with probing depths > or = 4 mm. The odds of periodontal disease (progression and/or current disease) were 1.55 times greater in subjects harboring prtH genotype T. forsythensis than in subjects in whom prtH was not detected. The prtH genotype was associated with higher numbers of T. forsythensis. In subjects with high levels of T. forsythensis, prtH genotype was associated with an increased extent of periodontal disease 2 years subsequently. CONCLUSIONS: These results show that T. forsythensis prtH genotype is associated with high levels of T. forsythensis. However, further work is needed to determine whether it also is a useful marker of periodontal disease progression in T. forsythensis-infected subjects.