Oral Microbiota Transplant in Dogs with Naturally Occurring Periodontitis.

In periodontitis patients, dysbiosis of the oral microbiota is not only found at clinically diseased periodontal sites but also at clinically healthy periodontal sites, buccal mucosae, tongue, and saliva. The present study evaluated the safety and efficacy of an oral microbiota transplant (OMT) for the treatment of periodontitis in dogs. Eighteen systemically healthy beagle dogs with naturally occurring periodontitis were enrolled in the study and randomly assigned to a test or control group. A 4-y-old, periodontally healthy female beagle dog served as a universal OMT donor. To reduce periodontal inflammation, all dogs received full-mouth mechanical debridement of teeth and mucosae 2 wk before baseline. At baseline, full-mouth mechanical debridement was repeated and followed by adjunctive subgingival and oral irrigation with 0.1% NaOCl. Subsequently, test dogs were inoculated with an OMT from the healthy donor. No daily oral hygiene was performed after OMT transplantation. Adverse events were assessed throughout the observation period. Clinical examinations were performed and whole-mouth oral microbiota samples were collected at week 2, baseline, week 2, and week 12. The composition of oral microbiota samples was analyzed using high-throughput 16S ribosomal RNA gene amplicon sequencing followed by taxonomic assignment and downstream bioinformatic and statistical analyses. Results demonstrated that the intergroup difference in the primary outcome measure, probing pocket depth at week 12, was statistically insignificant. However, the single adjunctive OMT had an additional effect on the oral microbiota composition compared to the full-mouth mechanical and antimicrobial debridement alone. The OMT resulted in an "ecological shift" toward the composition of the donor microbiota, but this was transient in nature and was not observed at week 12. No local or systemic adverse events were observed throughout the study period. The results indicate that OMT may modulate the microbiota composition in dogs with naturally occurring periodontitis and can be applied safely.

Success of a smoking cessation programme in smoking behaviour of chronic periodontitis patients and identification of predictors of motivation for smoking cessation - a pilot study.

BACKGROUND: The primary goal of this pilot study was to evaluate the success of a smoking cessation programme on smoking behaviour of patients with chronic periodontitis. Secondary goals were to identify the prevalence of smoking among them, predictors of motivation for smoking cessation and for successful nicotine abstinence. METHODS: Smokers suffering from chronic periodontitis were offered cognitive behavioural group therapy of 10 once-weekly sessions. Smoking is reduced stepwise and complete cessation is to be achieved by the sixth session. Sociodemographic data, history of smoking and motivation for smoking cessation, subjective health status, and questionnaires on anxiety, depression, control beliefs and coping with stress were completed at study entry. Smoking behaviour was assessed at the end of the group programme and 3 months thereafter. RESULTS: Of 469 patients with periodontitis, 59 (12.6%) were smokers; 30 (50.6%) patients participated in the smoking cessation programme. Participants smoked more cigarettes/day (P = 0.03, 95% CI: -17.9/-0.89) and subjectively assessed their health as being worse than non-participants (P = 0.09, 95% CI: -0.16/2.15). In SPQ, non-participants showed more trivialization (P = 0.014, 95% CI: 0.59/4.94). Complete data were available for 15 group participants: six patients were smoke-free after 10 weeks and five after 18 weeks (33.3%); two patients had reduced their cigarette consumption by half. At the start of the programme, less successful participants showed a tendency to higher depression in HADS (P = 0.085, 95% CI: -5.25/5.76) and were more inclined to seek substitute satisfaction (P = 0.034, 95% CI: 3.24/11.23). CONCLUSION: The rate of success in this study was comparable with other studies. More research with larger samples is needed for confirming these observations.

Protease inhibitor levels in periodontal health and disease.

BACKGROUND AND OBJECTIVE: Our previous study showed that protease inhibitors were attenuated by the periodontal pathogen Porphyromonas gingivalis in cultured gingival epithelial cells. We hypothesize that fewer protease inhibitors would be present in more advanced periodontal disease sites, where the level of P. gingivalis may be high. The goal of this study was to investigate the relationship between the protease inhibitor [secretory leukocyte protease inhibitor (SLPI), elastase-specific inhibitor (ELAFIN) and squamous cell carcinoma antigen (SCCA)] levels in gingival crevicular fluid and the number of P. gingivalis micro-organisms in subgingival plaque. MATERIAL AND METHODS: Plaque samples from subjects without (n = 18) and with moderate to advanced periodontitis (n = 41) were used to quantify P. gingivalis using real-time PCR. Protease inhibitor levels in the gingival crevicular fluid of all the subjects were determined by ELISA. RESULTS: P. gingivalis was detected in 68.3% of patients with periodontitis, while 16.7% of subjects without periodontitis had a detectable level of P. gingivalis. Patients with periodontitis and P. gingivalis in their plaque exhibited lower SLPI and ELAFIN levels (p < 0.001) compared with control subjects without periodontitis. Secretory leukocyte protease inhibitor was also reduced (p < 0.05) in gingival crevicular fluid of periodontitis patients without a detectable level of P. gingivalis. Periodontitis patients with high vs. low levels of P. gingivalis exhibited reciprocal mean levels of SLPI and ELAFIN concentrations. CONCLUSION: The reduced concentrations of SLPI and ELAFIN may contribute to the loss of host protective capacity and increase susceptibility to breakdown from chronic infection. The work of this investigation may aid in finding diagnostic and prognostic markers in periodontal health and disease and may also help in finding pharmacological targets directed against periodontal inflammation.

Sequence variations in rgpA and rgpB of Porphyromonas gingivalis in periodontitis.

OBJECTIVE: The aim of the present study was to determine sequence variations in the active centre of the Arg-X-specific protease encoding genes rgpA and rgpB of clinical Porphyromonas gingivalis isolates and to analyse their prevalence in periodontitis patients before and 3 months after mechanical periodontal therapy. BACKGROUND: Genetic diversity at nucleotides 281, 283, 286 and 331 has been shown to result in amino acid substitutions in the catalytic domain of RgpA and RgpB that affect the substrate specificity and thus may influence the efficacy of Arg-X-protease specific inhibitors. METHODS: Sequence analysis of rgpA and rgpB genes in clinical P. gingivalis strains isolated from subgingival plaque samples of 82 periodontitis patients before and 3 months after mechanical supra- and subgingival debridement was performed. RESULTS: No specific variation within the rgpA sequence was observed. However, the rgpB sequence in the region of the active centre showed five different rgpB genotypes, which were named NYPN, NSSN, NSSK, NYPK and DYPN according to the derived amino acid substitution. Porphyromonas gingivalis genotype NYPN was detected in 27 patients (32.9%) before and in 8 patients (9.8%) after therapy, NSSN in 26 (31.7%) and 10 (12.2%), NSSK in 22 (26.8%) and 2 (2.4%), NYPK in 5 (6.2%) and 1 (1.2%), and DYPN in 1 patient (1.2%) and 0 patients (0%), respectively. Only one patient (1.2%) harboured two P. gingivalis rgpB genotypes (NSSK/NYPN) before treatment; these were no longer detected after therapy. CONCLUSION: The results indicate that five rgpB genotypes are maintained in natural populations of P. gingivalis. These data may be of importance with regard to the development of specific rgpB inhibitors.

Establishing dental hygiene education in Germany: current facts and future perspectives.

As there is a marked need to increase the number of dental hygienists (DHs) working in German dental practices, efforts are being made to establish dental hygiene education in accordance with international standards. However, as current German legislation does not envisage a perennial full-time training programme, dental hygiene education may currently be provided within a modular concept only. The basic qualification for enrollment in a modular hygienist training programme of this kind is accredited vocational training as a dental assistant (DA), followed by board-certified continuing education as an oral prophylaxis assistant. Thus, the current system of advanced training for qualification as a DH is subject to at least 6 years' work experience in the field of dentistry. A 950-h full-time advanced training course, meeting all the requirements of this concept, was established by the Westphalia-Lippe Dental Association in cooperation with the University of Münster. The curriculum underlying this programme was outlined considering the recommendations for dental hygiene education issued by the European Federation of Periodontology, although reduced in standards to comply with current German legislation. In addition, the recommendations for American Dental Hygiene education by the American Dental Association were used as a guide for programme development. The contents and implementation of the Münster Dental Hygienist Curriculum may allow the professional competence generated during practical work experience to be linked with international requirements of dental hygiene education.

Sequence analysis of kgp in Porphyromonas gingivalis isolates from periodontitis patients.

The aim of the present study was to determine sequence variation in the Lys-x-specific protease (Kgp) encoding gene kgp of Porphyromonas gingivalis and to analyze its association with periodontal disease severity. Pooled subgingival plaque samples were obtained from the six most severely affected sites of 102 patients with periodontitis. Sequence analysis of the kgp gene in 23 clinical P. gingivalis isolates resulted in the identification of two distinct kgp types (kgp-I and kgp-II) according to sequence differences in the region encoding the catalytic domain. Restriction analysis revealed that 59 of the 102 patients were colonized by kgp-I and 43 by kgp-II. Patients harboring kgp-I or kgp-II showed no significant difference in the severity of periodontal disease as assessed by pocket probing depth and bleeding on probing following adjustment for smoking habit and age. Moreover, no differences in proteolytic activity of Kgp-I and Kgp-II were detected. The results indicated that two kgp types are maintained in natural populations of P. gingivalis.

Serum antibody reactivity against recombinant PrtC of Porphyromonas gingivalis following periodontal therapy.

OBJECTIVES: In 34 patients with chronic periodontitis, the presence of IgA, IgG, and IgG subclass serum antibodies against recombinant PrtC (rPrtC) of Porphyromonas gingivalis was assessed by immunoblot analysis 24 months after therapy. METHODS: rPrtC was produced from P. gingivalis ATTC 33277 using the plasmid pGEX-2T. In addition, intraoral colonization with P. gingivalis was detected by PCR in subgingival plaque and swab samples from buccal mucosae, tonsils and tongue at baseline, 10 d, and 3, 6, 9, 12, 18, and 24 months. RESULTS: All patients were found to harbor P. gingivalis in the oral cavity at least once during the observation period. The identified antibody responses against the rPrtC of P. gingivalis were IgA (97%, i.e. 33/34 patients) and IgG (100%, i.e. 34/34), with an IgG subclass distribution of IgG2 (65%, i.e. 22/34 patients) > IgG3 (47%, i.e. 16/34) > IgG1 (38%, i.e. 13/34) > IgG4 (29%, i.e. 10/34). Anti-rPrtC IgA and IgG antibody reactivity was found in all but one patients (anti-rPrtC IgA negative), who tested negative for P. gingivalis at all of the assessed intraoral sites for at least 6 months before sera collection. There was no association between IgG subclass reactivity against the rPrtC of P. gingivalis and progression of periodontal attachment loss. CONCLUSION: The results indicated that anti-rPrtC IgA and IgG antibodies may serve as an indicator for past or present intraoral colonization with P. gingivalis.

Subgingival plaque removal in buccal and lingual sites using a novel low abrasive air-polishing powder.

AIM OF THE STUDY: This study was aimed at assessing the efficacy of subgingival plaque removal in buccal and lingual sites during supportive periodontal therapy (SPT) using a novel low abrasive air-polishing powder. MATERIAL AND METHODS: In 27 SPT patients, subgingival debridement was performed using the novel air-polishing powder (test) and hand instruments (positive control) in a randomized split mouth design. Before and immediately after treatment, subgingival plaque samples were taken from two teeth with pockets of 3-5 mm depth in both groups. To assess the influence of plaque sampling on the microflora, samples were also taken twice from two untreated teeth (negative control). The mean reduction in total colony forming units (CFU) was assessed by anaerobic culture. The patients' perception of treatment was assessed by a visual analog score (VAS). Therapy and plaque sampling were repeated after a 3-month interval. RESULTS: Test treatment resulted in a significantly greater reduction in mean CFU than positive control treatment (log 1.7+/-0.98 and log 0.61+/-0.79 respectively; p<0.05). Following both treatments, the CFU reduction was significantly greater compared to negative control treatment (log 0.06+/-0.49; p<0.05). In addition, test treatment was perceived as significantly more pleasant than hand instrumentation (p<0.05). CONCLUSION: The novel low abrasive air-polishing powder is superior to curettes in removing subgingival plaque from pockets of 3-5 mm depth in supportive periodontal therapy and offers greater patient comfort.

Guided tissue regeneration using a polylactic acid barrier.

OBJECTIVES: The purpose of this study was to determine the relative impact of various predictors responsible for the variability in treatment outcome after guided tissue regeneration (GTR) in intraosseous periodontal defects. PATIENTS AND METHODS: 30 patients with chronic periodontitis and at least one intraosseous periodontal lesion (> or =4 mm) were enrolled. Following full-mouth scaling, GTR using polylactic acid membranes was performed at one site in each patient. Main periodontal pathogens, defect morphology, membrane exposure and smoking habit were assessed as predictor variables. Alveolar bone level change served as the primary outcome variable in a multiple regression analysis. RESULTS: After 12 months, the 29 patients completing the study showed alveolar bone changes ranging from 4 mm bone gain to 1 mm bone loss (mean: 1.6+/-0.4 mm gain). Active smoking (beta-weight:-0.49, P=0.003) and persistence of subgingival infection with P. gingivalis (P.g.) (beta-weight:-0.25, P=0.11) were associated with poor treatment outcome. Deep initial intraosseous defects (beta-weight: 0.32, P=0.045) were associated with favorable treatment outcome, and membrane exposure had no impact on bone gain. CONCLUSION: Active smoking was the strongest predictor variable negatively affecting alveolar bone gain following GTR in the treatment of periodontal defects. It was followed by a positive influence of a deeper intraosseous defect and by a negative effect by persistent subgingival infection of P. gingivalis. The relative impact of these factors may be useful in assessing the prognosis of GTR in intraosseous periodontal defects.

In vitro evaluation of novel low abrasive air polishing powders.

AIM OF THE STUDY: Though efficient in stain and plaque removal, air polishing is highly abrasive on root cementum or dentin even if working parameters are adjusted to minimize damage. As abrasiveness is also influenced by the physical properties of the powders used, the aim of the study was to evaluate the safety of novel low abrasive air polishing powders in vitro. MATERIAL AND METHODS: Using four novel air polishing powders (A, B, C and D) and a standard sodium bicarbonate (NaHCO3) powder, roots of 126 extracted teeth were air polished under standardized conditions at various working parameter combinations (distance: 2 mm, 4 mm and 6 mm; powder and water setting: low, medium and high) at an angulation of 90 degrees for 20 s. Instrumentation was performed in triplicate; resulting root defects were quantified laser-optically. RESULTS: Mean defect depths after application of powders A, B, C and D were significantly lower than with standard powder (A: 17.9 +/- 10.9 micro m, B: 48.2 +/- 32.7 micro m, C: 92.5 +/- 57.9 micro m, D: 33.9 +/- 19.6 micro m, NaHCO3: 163.1 +/- 71.1 micro m) (Kruskal-Wallis test). Among the experimental powders, D was transported most reliably in the air polishing unit and allowed complete removal of disclosed plaque as assessed on freshly extracted teeth. CONCLUSION: The novel air polishing powder D is of low abrasiveness to root cementum and dentin while being effective in removing dental plaque. Thus, it may be useful for safe and efficient plaque removal on exposed root surfaces.

Guided tissue regeneration using a polylactic acid barrier. Part I: Environmental effects on bacterial colonization.

OBJECTIVES: The purpose of this study was to assess the dynamics of bacterial colonization in intra-osseous defects following guided tissue regeneration (GTR) therapy using a resorbable barrier. PATIENTS AND METHODS: In each of 30 patients, one intra-osseous defect was treated with GTR using a polylactic acid membrane (Guidor). Plaque samples were taken from the defect site, other teeth and mucous membranes following initial therapy (baseline), and at 3, 6 and 12 months after periodontal surgery. Additionally, samples were taken from the defect sites at 1, 2 and 4 weeks. Actinobacillus actinomycetemcomitans (A.a.), Porphyromonas gingivalis (P.g.), and Bacteroides forsythus (B.f.) were detected by polymerase chain reaction (PCR). Supportive periodontal therapy was performed at 3-month intervals. RESULTS: In the 29 patients completing the study, the assessed microflora was detected in 3 (A.a.), 13 (P.g.) and 14 (B.f.) defect sites at baseline, in 2 (A.a.), 2 (P.g.) and 2 (B.f.) following surgical debridement, and in 6 (A.a.), 10 (P.g.) and 22 (B.f.) at 12 months. Defect site colonization following GTR therapy was significantly correlated with presurgical colonization at other assessed teeth (A.a. and P.g.: tau = 0.45 and 0.66, respectively; P < 0.001), or on mucous membranes (B.f.: tau = 0.44, P < 0.001). CONCLUSION: The colonization of periodontal pathogens at sites treated by GTR may correlate with the intra-oral presence of these pathogens before surgery. If colonization of GTR sites by periodontal pathogens is to be prevented, intra-oral suppression/eradication of these pathogens may be required before surgery.

Eruption cyst formation associated with cyclosporin A.

BACKGROUND: Cyclosporin A (CyA) is a potent immunomodulatory agent with a wide range of applications. Despite its therapeutic value, multiple adverse effects of CyA have been identified. This case report describes eruption cyst formation as a possible adverse effect of CyA administration during tooth eruption in a boy treated with CyA as a consequence of a cardiac transplantation. The clinical diagnosis of eruption cyst was confirmed by histopathological examination. TREATMENT: The periodontal treatment consisted of supragingival and subgingival scaling, followed by surgical removal of the tissues overlying the crowns of the teeth associated with eruption cysts, and flap surgery in the region of gingival overgrowth. The patient was then placed on quarterly periodontal supportive therapy and his immunosuppressive medication was switched from CyA to tacrolimus. RESULTS: Twenty months after therapy, neither new cyst formation nor recurrence of gingival overgrowth was registered. CONCLUSION: Formation of an eruption cyst may be an adverse effect of CyA in children with erupting teeth.

Root defects following air polishing.

AIM: Air-polishing devices (APDs) are highly effective in removing plaque and extrinsic staining. Their application on root surfaces, however, may result in clinically relevant substance removal, limiting the use in patients with periodontitis, where denuded root surfaces are frequently found. Therefore, the purpose of the study was to assess the influence of different working parameters on root damage and to identify those minimizing root damage. MATERIAL AND METHODS: Defect depth and defect volume after instrumentation of roots with an APD (Dentsply Prophy-Jet) using conventional NaHCO3 powder at instrumentation times of 5, 10 and 20 s, combinations of low, medium and high powder and water settings, distances of 2, 4 and 6 mm, and angulations of 45 degrees and 90 degrees were quantified laseroptically. A total of 297 roots were instrumented and parameter combinations were performed in triplicate. The influence of each working parameter on substance loss was determined by multiple regression analysis. RESULTS: Time had the greatest influence on defect volume and depth (beta-weights 0.6 and 0.57, respectively), when compared with powder setting (beta-weights 0.49 and 0.3) and water setting (beta-weights 0.28 and 0.3). Variations in distance affected defect depth (beta-weight 0.44), but not volume (beta-weight 0.04). No major differences were found at 45 degrees and 90 degrees. Various parameter combinations led to maximal defect depths of 473.5 +/- 26.2 micro m within 20 s. CONCLUSION: Root damage varies among combinations of working parameters. Using the APD with the assessed NaHCO3 powder, all parameter combinations led to substantial root damage. Thus, APDs using NaHCO3 may not be safely utilized on exposed root surfaces.

Assessment of root curvature and distance using computed tomography.

The safety and efficacy of subgingival root surface instrumentation may be enhanced by optimized adaptation between instrument and treated surface. Thus, detailed knowledge of root geometry may allow advances in instrument design. The aim of this study was therefore to measure root radii of various tooth types as well as distances between tooth roots using computed tomography. Two hundred sixteen teeth in eight patients were studied, with cross sections of teeth at the level of the cemento-enamel junction (CEJ) being regarded as ellipses. The maximum radii of ellipses were calculated and averaged for each tooth surface within various tooth groups. In addition, the spacing between roots at CEJ level and 5 mm below the CEJ was measured. Mean radii varied from 1.09+/-0.50 mm (lower incisor, lingual) to 13.7+/-0.96 mm (upper molar, mesial). Radii of 1 mm to 6 mm were most frequently found at buccal, palatal, and lingual surfaces, whereas the majority of radii were between 2 mm and 11 mm at mesial and distal sites. Root distance varied between 1.04+/-0.49 mm (lower incisors, CEJ level) and 2.81+/-1.70 mm (lower molars, 5 mm below CEJ). The curvature of an instrument for root surface instrumentation should correspond to a radius of at least 11 mm to achieve maximum adaptation to the treated surface, and the width of the working end should be less than 1 mm to allow sufficient interdental instrumentation.

In-dental-office screening for diabetes mellitus using gingival crevicular blood.

BACKGROUND: Diabetes mellitus (DM) is undiagnosed in approximately 1/2 of the patients actually suffering from the disease. In addition, the prevalence of DM is more than 2x as high in patients with periodontitis when compared to periodontally healthy subjects. Thus, a high number of patients with periodontitis may have undiagnosed DM. AIM: The purpose of this pilot study was to evaluate, whether blood oozing from gingival tissues during routine periodontal examination can be used for determining glucose levels. 32 non-diabetic and 13 diabetic patients with moderate to severe periodontitis were enrolled and subjected to routine clinical periodontal examination. Periodontal pocket probing was performed using a standard force. Blood oozing from gingival tissues of anterior teeth following periodontal pocket probing was collected with the stick of a glucose self-monitoring device (Elite(R) 2000, Bayer Diagnostics GmbH, Munich). As control, fingerstick capillary blood was taken. Statistical analysis was performed by Pearson's correlation coefficient. RESULTS: The patient blood glucose levels ranged from 3.57 mmol/l to 18.01 mmol/l and the values of blood samples taken from gingiva or finger tip showed a very high intrapatient correlation (r=0.98; p<0.0001). CONCLUSION: The results suggested that blood oozing during routine periodontal examination may be used for diabetes mellitus screening in a dental office setting.

A systematic review of efficacy of machine-driven and manual subgingival debridement in the treatment of chronic periodontitis.

OBJECTIVES: The purpose of this systematic review was to determine the efficacy of machine-driven compared with manual subgingival debridement in the treatment of periodontitis. BACKGROUND: Mechanical debridement of the periodontal pocket plays a pivotal role in the treatment of periodontitis. METHODS: A literature search for controlled clinical trials with at least 6 months' follow-up comparing machine-driven instruments with hand instruments for the treatment of chronic periodontitis was performed up to April 2001. Screening of titles and abstracts as well as data extraction was conducted independently by two reviewers (J.T. & T.F.F.). As primary outcome variable, the prevention of tooth loss was used; secondary outcome variables were the prevention of disease progression, the resolution of anatomical defects and the resolution of gingival inflammation. Efficiency was assessed by mean time needed to treat one tooth. RESULTS: From a total of 419 abstracts, 27 articles were included for the review. The weighted kappa score for agreement between the two reviewers was 0.77, 95% CI: 0.65-0.89, indicating substantial agreement. No study reported on the selected primary outcome variables. Using clinical attachment gain, probing pocket depth reduction or bleeding on probing reduction as outcome variables, there appeared to be no differences between ultrasonic/sonic and manual debridement. No major differences in the frequency or severity of adverse effects were found. However no meta-analysis could be performed on any of the previously mentioned parameters. Ultrasonic/sonic debridement was found to take significantly less time, i.e. 36.6%, than debridement using hand instruments (P = 0.0002, 95% CI of the standardized effect estimate: 0.39-1.37, heterogeneity P = 0.77). CONCLUSIONS: With respect to clinical outcome measures, the available data do not indicate a difference between ultrasonic/sonic and manual debridement in the treatment of chronic periodontitis for single-rooted teeth; however, the evidence for this is not very strong. In addition, ultrasonic/sonic subgingival debridement requires less time than hand instrumentation. Further research is needed to assess the efficacy of machine-driven debridement on multirooted teeth and clinical outcome variables having tangible benefit to the patients should be used.

Lack of antimicrobial effect on periodontopathic bacteria by ultrasonic and sonic scalers in vitro.

BACKGROUND: The purpose of this study was to assess the antimicrobial effects of a sonic and ultrasonic scaler generally used for subgingival scaling on gram-negative and gram-positive periodontopathic bacteria. METHOD: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Campylobacter rectus, or Peptostreptococcus micros were suspended in Schaedler's broth medium and treated by a sonic or a magnetostrictive ultrasonic scaler for 30 s and 150 s in vitro. Bacterial suspensions treated by an ultrasonic cell disruptor served as a positive control and untreated bacterial suspensions served as a negative control. Following sonication, samples were serially diluted, streaked on blood agar plates and incubated for 2-5 days at 37 degrees C. RESULTS: Treatment by the sonic or ultrasonic scaler for up to 150 s did not reduce the viability of any of the tested periodontal pathogens. Compared to untreated controls, the viability of A. actinomycetemcomitans and P. gingivalis was significantly (p<0.05) reduced only following ultrasonication with the cell disruptor after 30 s (0.72 and 0.54 log CFU/ml, respectively) and of A. actinomycetemcomitans, P. gingivalis, C. rectus, and P. micros after 150 s (1.98, 1.34, 1.95 and 1.98 log CFU/ml, respectively). CONCLUSION: The data of the study may indicate that the assessed sonic and ultrasonic scaler used for subgingival debridement do not result in killing of the tested periodontal pathogens.

Heterogeneity of the prtC gene of Porphyromonas gingivalis.

In this study, the nucleotide sequences of the prtC genes of six clinical Porphyromonas gingivalis isolates obtained from patients with periodontitis and from reference strain 53977 were determined. All analyzed genes were heterogeneous in their nucleotide composition and differed in up to 13 nucleotides. Moreover, substantial differences were found in comparison to prtC of reference strain 53977. The prtC genes of 45 Porphyromonas gingivalis isolates were amplified by polymerase chain reaction (PCR) and the PCR products were also digested with restriction endonucleases Tsp509I, NlaIII and DraII (PCR-restriction fragment-length polymorphism). Nine different restriction pattern combinations were observed, with four being most frequent (28.9%, 26.7%, 17.8% and 11.1%). The data presented here demonstrates that prtC genes are heterogeneous in their nucleotide sequence and therefore may be used as a target for molecular epidemiological studies. The observed heterogeneity of prtC genes may be a result of microevolution processes.

Interleukin-1 haplotype and periodontal disease progression following therapy.

The purpose of this study was to assess the prognostic value of the IL-1 haplotype on the progression of periodontal disease following therapy. 48 adult patients with untreated periodontitis harboring Actinobacillus actinomycetemcomitans and/or Porphyromonas gingivalis were randomly assigned to receive full-mouth scaling alone (control) or in combination with systemic metronidazole plus amoxicillin and supragingival irrigation with chlorhexidine digluconate (test). All patients received supportive periodontal therapy at 3 to 6 months intervals. In 33 patients, lymphocyte DNA was analyzed for polymorphism in the IL-1A gene at position -889 and IL-1B gene at position +3953. Overall, 16 of 33 patients (7 of 17 test and 9 of 16 control) carried the IL-1 haplotype. 2 years following initial periodontal therapy, no differences in the survival rates of sites or teeth not exhibiting probing attachment loss of 2 mm or more compared to baseline, were found between patients who tested positive (85% sites, 53% teeth) and patients who tested negative (89% sites, 56% teeth) for the IL-1 haplotype. The results indicated that the IL-1 haplotype may be of limited value for the prognosis of periodontal disease progression following non-surgical periodontal therapy.