Five-year radiological findings from a randomized controlled trial of four periodontitis treatment strategies

Radiographic findings from long-term studies of periodontitis treatment have rarely been reported. Although bone destruction is a prominent feature of periodontitis, the long-term effect on alveolar bone levels of different treatment strategies, with or without adjunctive metronidazole (MTZ), has not been reported. We investigated the 5-year radiographic outcome of therapy in patient groups treated with conventional scaling and root planing (SRP) or same-day full-mouth disinfection (FDIS), with or without adjunctive MTZ. Following a 3-month oral hygiene phase, 184 periodontitis patients were randomly allocated to one of four treatment regimens: (i) FDIS+MTZ; (ii) FDIS+placebo; (iii) SRP+MTZ; or (iv) SRP+placebo. Following active treatment, patients received biannual maintenance. In total, 161 patients (87.5%) completed the 5-year follow-up examination, at which the radiographic bone level (RBL), clinical attachment level, probing pocket depth, presence of plaque, and bleeding were recorded again. At the 5-year follow up examination, minor radiological bone loss was observed in the intervention groups FDIS+placebo, SRP+MTZ, and SRP+placebo; by contrast, the FDIS+MTZ group did not show any change in RBL. Full-mouth disinfection did not generally perform better than conventional SRP performed over a period of 2 to 4 weeks.

The anti-plaque effect of high concentration sodium bicarbonate dentifrice on plaque formation and gingival inflammation, irrespective to individual polishing technique and plaque quality

AIM

To assess the anti-plaque effect of a high concentration sodium bicarbonate dentifrice on plaque formation, and gingivitis, as compared to a control toothpaste, irrespective of individual brushing technique and plaque quality.

METHODS

The experimental gingivitis model, with a split-mouth design was used to assess the anti-plaque effect of a high concentration sodium bicarbonate dentifrice on plaque formation. By producing individual fitted trays, the toothpaste was applied in the test quadrant and a control dentifrice in the contralateral. The participants used the individual fitted trays for 1 min every morning and evening, for 21 days. In this period, the participants was only allowed to brush the teeth in the opposite jaw, as usual. Twenty healthy individuals successfully completed the study.

RESULTS

At 21 days, there was no statistically significant difference between test quadrant and control quadrant with regard to plaque indices, gingival index and number of bleeding sites.

CONCLUSION

This study demonstrated that the high concentration sodium bicarbonate dentifrice used did not produce statistically significant anti-plaque effect compared to the control dentifrice, in terms of Plaque- and Gingival Indices, number of bleeding sites or by Quigely and Hein, the Turesky modification Plaque Index, irrespective of brushing technique and individual plaque quality.

TRIAL REGISTRATION

Regional Committee for Medical Research and Ethics, South-East Norway in 2021 (REK.2021/370116).

CLINICAL TRIAL REGISTRATION

NCT05441371 (First registered 09/06/2022, First posted 01/07/2022) ( http://www.

CLINICALTRIALS

gov ). (Retrospectively registered).

Comparison of commercially available 0.2% chlorhexidine mouthwash with and without anti-discoloration system: A blinded, crossover clinical trial

AIM

To evaluate clinical performance and side effects of two commercially available 0.2% chlorhexidine mouthwashes after periodontal surgery, one with (test) and one without (control) an anti-discoloration system.

MATERIALS AND METHODS

This single-centre, crossover clinical trial included 38 patients undergoing two sessions of periodontal flap surgery. The participants used two different 0.2% chlorhexidine products, one with and one without an anti-discoloration system, in the 14-day post-operative periods. Plaque, gingival inflammation, tooth staining, side effects and patient preference were evaluated.

RESULTS

The control mouthwash (without an anti-discolouring system) produced significantly lower plaque (p = 0.02) and gingival index (p = 0.01) compared to the test mouthwash. The test mouthwash produced significantly less staining in the gingival (p = 0.002) and approximal areas (p = 0.0004), but no difference was detected in the buccal area of the teeth. The patients did not show preference for any of the mouthwashes.

CONCLUSION

Chlorhexidine mouthwash without an anti-discoloration system resulted in significantly lowered plaque and gingival index compared to chlorhexidine mouthwash with an anti-discoloration following periodontal surgery. No difference in patient preference was found despite less side effects produced by the chlorhexidine mouthwash with the anti-discoloration system.

Radiographic alveolar bone level and levels of serum 25-OH-Vitamin D3 in ethnic Norwegian and Tamil periodontitis patients and their periodontally healthy controls

BACKGROUND

Studies suggest association between low serum 25-OH-Vitamin D₃ (VitD) and chronic destructive periodontal diseases. The main sources of VitD is sun exposure and fat fish. Subjects with dark skin will therefore generate less VitD as response to sun exposure. The aim of the study was to assess the radiographic bone level and levels of serum VitD in ethnic Norwegian and Tamil periodontitis patients and their respective healthy controls.

METHODS

Twenty-seven Tamil periodontitis patients living in Norway were compared to 21 Tamil controls as well as to 21 Norwegian periodontitis patients and 23 Norwegian controls. Marginal bone level was diagnosed on radiographs. VitD levels were diagnosed in blood samples by high-performance liquid chromatography-mass spectrometry.

RESULTS

VitD levels were lower in Norwegian periodontitis patients than in controls, while no significant differences were observed between Tamil periodontitis patients and controls despite the significant difference between RBL between the periodontitis patients and controls in both groups. When calculating the odds ratio for having periodontal disease in both populations together, it appeared that one unit increased serum VitD (i.e. 1 nmol/L) decreased the odds of having radiographic bone loss by 4%.

CONCLUSION

According to logistic regression, and after correcting for confounding factors, VitD levels showed significant association with the presence of periodontitis, as expressed by radiographic bone loss, in all patients combined.

Oral hygiene phase revisited: How different study designs have affected results in intervention studies

Every periodontal researcher have been taught, and every textbook in periodontics have advocated, that a phase in which the patient is meticulously motivated and instructed in proper oral hygiene-the oral hygiene phase-must be included in any periodontal intervention. However, how is this oral hygiene phase actually portrayed in periodontal intervention studies, and how much space have this important phase received in the planning and carry-through of intervention studies? The purpose of this letter to the editor was to review current literature in the period 1975/01/01-2017/12/31 on periodontal, mechanical intervention studies in order to see what focus the oral hygiene phase had received in these articles. The result showed that the oral hygiene phase is variable in length and content, variable in claimed result, insufficiently described, and invariably amalgamated with the scaling and root planing which is the intervention or part of an intervention. The consequences of these findings are discussed and suggestions proposed for more harmonized and calibrated oral hygiene phase introduced to avoid biased and inflated results of interventions.

The plaque and gingivitis inhibiting capacity of a commercially available mouthwash containing essential oils and ethyl lauroyl arginate. A randomized clinical trial

OBJECTIVE

A commercially available mouth rinse with ethyl lauroyl arginate and essential oils claims to have better antimicrobial properties than the traditional essential oil products. The aim of this study was to compare the plaque and gingivitis inhibiting effect of the commercial product containing essential oils with ethyl lauroyl arginate with one placebo and one negative control in a modified experimental gingivitis model.

MATERIALS AND METHODS

In three groups of healthy volunteers, experimental gingivitis was induced and monitored over 21 d, simultaneously treated with the commercial test solution, 21.6% hydro-alcohol solution and sterile water, respectively. The maxillary right quadrant of each individual received mouthwash only, whereas the maxillary left quadrant was subject to both rinsing and mechanical oral hygiene. Compliance and side effects were monitored at d 7, 14, and 21. Plaque and gingivitis scores were obtained at baseline and d 21.

RESULTS AND CONCLUSION

Although the commercial product containing essential oils with ethyl lauroyl arginate performed statistically significantly better regarding average plaque scores on all surfaces combined than the placebo (p = .018) and negative control (p = .003) when no mechanical tooth cleaning was performed, the product still left the patient with enough plaque to cause gingivitis and thus seemed of questionable clinical benefit to the patient. ClinicalTrials.gov Identifier is NCT02884817.

Comparing the effect of 0.06% -, 0.12% and 0.2% Chlorhexidine on plaque, bleeding and side effects in an experimental gingivitis model: a parallel group, double masked randomized clinical trial

BACKGROUND

Chlorhexidine is the gold standard of dental plaque prevention. The aim of the present study was to compare the plaque and gingivitis inhibiting effect of commercial products containing 0.2%, 0.12% and 0.06% chlorhexidine in a modified experimental gingivitis model.

METHODS

In three groups of healthy volunteers, experimental gingivitis was induced and monitored over 21 days and simultaneously treated with the commercial solutions containing 0.2%, 0.12% and 0.06% chlorhexidine. The maxillary right quadrant of each individual received mouthwash only, whereas the maxillary left quadrant was subject to both rinsing and mechanical oral hygiene. Compliance and side effects were monitored at days 7, 14, and 21. Plaque and gingivitis scores were obtained at baseline and day 21.

RESULTS

The commercial mouthwash containing 0.2% chlorhexidine resulted in statistically significantly lower plaque scores than the 0.12 and 0.06% mouthwashes after 21 days use, whereas no statistically significant difference was found between the effects of the two latter.

CONCLUSION

A commercially available mouthwash containing 0.2% chlorhexidine had statistically significant better effect in preventing dental plaque than the 0.12% and 0.06% solutions.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02911766 . Registration date: September 9th 2016.

Antibiotic-prescribing habits among Norwegian dentists: a survey over 25 years (1990-2015)

Bacterial antibiotic resistance is a steadily growing global problem, which today is compared with issues such as global warming, ozone depletion, and extinction of species. Consequently, calls come from global, Pan-European, and national authorities to gain insight into, limit, and stringently qualify the use of antibiotics in human and veterinary medicine, as well as in food production. Dentists are not considered to be frequent prescribers of antibiotics. However, few studies have identified how much, and in which situations, dentists prescribe such drugs. The aims of the present study were to survey Norwegian dentists' antibiotic-prescribing habits in 2015 and to compare the findings with previous studies (1990 and 2004) and with the actual numbers of dispensed prescriptions obtained from the 'Norwegian National Prescription Register'. The results from 1990 to 2004 show that there was a general increase in antibiotic prescriptions by Norwegian dentists, followed by a reduction or flattening of the prescription volume curve from 2004 to 2015. Despite this, possibilities for further improvements have been identified and recommendations given for targeted campaigns to reduce the prescription volume in dentistry by a further 30%, which has been ordered by the Norwegian National Assembly.

A Randomized Double-Masked Clinical Trial Comparing Four Periodontitis Treatment Strategies: 5-Year Tooth Loss Results

BACKGROUND

Tooth loss is the ultimate negative consequence of periodontitis, and reports of the extent to which different treatment strategies may influence long-term tooth loss are hard to find. This study aims to test the hypothesis that there is no difference in 5-year clinical outcome of therapy in terms of tooth mortality between groups of patients treated with conventional scaling and root planing (SRP) over weeks or same-day full-mouth disinfection (FDIS), with or without adjunctive metronidazole (MET).

METHODS

One hundred eighty-four patients with moderate-to-severe periodontitis were randomly allocated to one of four treatment groups: 1) FDIS+MET; 2) FDIS+placebo; 3) SRP+MET; and 4) SRP+placebo. Total 161 patients (88%) completed the 5-year follow-up examination, and data on number and timing of tooth extractions as well as pre-extraction diagnoses and reasons for extractions were analyzed.

RESULTS

No differences were observed between groups with regard to number of, reasons for, or time of extractions in the four groups at baseline and 1, 3, and 5 years after treatment.

CONCLUSION

If extraction or retention of teeth is regarded as a measure of failure or success 5 years after completion of periodontal therapy, none of the four strategies produced an end result better than the other.

Patients' perception of own efforts versus clinically observed outcomes of non-surgical periodontal therapy in a Norwegian population: an observational study

BACKGROUND

Most periodontal intervention studies have focused on biomedical qualities like change in pocket depth and clinical attachment levels. Very few studies have described patient response in terms of how patients' general lives are affected by disease, treatment, and communication with therapy providers. Thus the aim of the present study was to investigate patient response to systematic periodontal information, motivation and treatment strategy (primary aim) by comparing the patients' perception of own efforts and results with those clinically registered in a trans-sectional, observational study (secondary aim).

METHODS

One year after treatment of 184 patients, 152 completed a questionnaire covering aspects of received oral health information and instruction, expectations, communication with the therapeutic team, behavioral change, self-perceived outcomes and satisfaction.

RESULTS

More than 90% of the patients were satisfied with the interaction with the specialist team. 98% were satisfied with the information and instruction they had been given. 84% said that the information had been necessary to make them change their behavior towards better oral hygiene. Pain and discomfort, as well as bleeding were reduced substantially from before to after treatment, and 28 patients reported to have stopped smoking. In all questions regarding well-being there were statistically significant changes towards positive impact following therapy.

CONCLUSIONS

Periodontal treatment, including customized information and education on the etiology and pathogenesis, prevention and treatment as well as maintenance of periodontal diseases resulted in a high degree of short- and long term compliance, and very good patient centered outcomes, which again had a positive impact on the patients' satisfaction. The patient centered outcomes correlated mostly with the compared clinical endpoints.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01318928.

The effect of metronidazole on the presence of P. gingivalis and T. forsythia at 3 and 12 months after different periodontal treatment strategies evaluated in a randomized, clinical trial

OBJECTIVE

The benefit of full-mouth disinfection (FDIS) over traditional scaling and root planing (SRP) in the treatment of chronic, destructive periodontitis remains equivocal and it is not known whether the use of adjunctive antibiotics may enhance the effect of FDIS. Therefore, the aim of this study was to evaluate the effect of conventional SRP completed over 21 days or 1-day FDIS, with or without systemically delivered adjunctive metronidazole (MET) on the presence of P. gingivalis and T. forsythia after 3 and 12 months.

MATERIALS AND METHODS

One hundred and eighty-four patients with moderate-to-severe periodontitis were randomly allocated to one of four treatment groups; (1) FDIS+MET; (2) FDIS+placebo; (3) SRP+MET; (4) SRP+placebo. Prior to treatment, pooled subgingival samples were obtained from the five deepest pockets. The same sites were sampled again 3 and 12 months after treatment. All samples were analyzed for P. gingivalis and T. forsythia by PCR, whereas A. actinomycetemcomitans and other bacteria were identified by culture techniques.

RESULTS

At baseline, 47% of the samples were positive for P. gingivalis, while almost all samples were positive for T. forsythia. The occurrence of P. gingivalis and T. forsythia was significantly reduced at 3 and 12 months after treatment in the FDIS+MET group, but not in the other treatment groups.

CONCLUSION

FDIS+MET had a significant effect in patients with P. gingivalis and T. forsythia, resulting in a significant reduction in number of patients where these micro-organisms could be detected at 3 and 12 months post-therapy.

Microbiologic Observations After Four Treatment Strategies Among Patients With Periodontitis Maintaining a High Standard of Oral Hygiene: Secondary Analysis of a Randomized Controlled Clinical Trial

BACKGROUND

The benefit of full-mouth disinfection (FDIS) over traditional scaling and root planing (SRP), with or without adjunctive metronidazole, when treating chronic destructive periodontitis remains equivocal, as does the long-term association between clinical and microbiologic outcomes after such strategies. The aim of this study is to examine the relationship between clinical and microbiologic outcomes of four different treatment strategies for chronic destructive periodontitis among patients who maintain excellent oral hygiene and low gingival bleeding scores.

METHODS

One hundred eighty-four patients with periodontitis and capable of maintaining a high standard of oral hygiene were randomly allocated to one of four treatment groups: 1) FDIS + metronidazole; 2) FDIS + placebo; 3) SRP + metronidazole; and 4) SRP + placebo. Recordings of plaque, bleeding on probing, probing depth (PD), and clinical attachment level were carried out in four sites per tooth at baseline, 3 and 12 months after treatment. Before treatment, pooled subgingival samples were obtained from the five deepest pockets, which were sampled again 3 and 12 months after treatment. Microbiologic assessments of eight putative periodontal pathogens were performed using the checkerboard DNA-DNA hybridization method.

RESULTS

Levels of bacterial species were already relatively low at baseline. The only microbial factor statistically significantly associated with the clinical outcomes of treatment after 12 months was the association between reductions of Tannerella forsythia and being free from PD ≥5 mm.

CONCLUSION

In this clinical trial, the only microbial factor associated with the clinical outcomes after 12 months was a statistically significant association between the reductions of T. forsythia and being free from PD ≥5 mm.

Periodontitis in psoriasis patients: a blinded, case-controlled study

OBJECTIVE

Destructive periodontitis is one of the most frequent and widespread bacterial infections in humans. Psoriasis is a common condition in the general population. Since both psoriasis and periodontal diseases are characterized by an exaggerated response of the immune system to the epithelial surface microbiota, there may possibly be an association between these two conditions. The aim of the present pilot study was to investigate the prevalence of periodontal disease in psoriasis patients compared to healthy controls.

MATERIAL AND METHODS

Dental bite-wing X-rays were obtained from 155 psoriasis patients aged 45-60 years, as well as from 155 age- and gender-matched controls. All X-rays were examined by the same investigator for accumulated destructive periodontitis using bone level and loss of teeth as endpoints.

RESULTS

A significantly lower radiographic bone level (p < 0.001) and a significantly higher number of missing teeth (p < 0.001) were observed in the psoriasis cases compared to the controls.

CONCLUSION

Our study indicates that psoriasis patients experience more bone loss than age- and gender-matched controls.

Antibiotic prescribing practices among Norwegian dentists

OBJECTIVE

There is little information on antibiotic prescribing habits among dentists in general. In 1992 we reported a study among Norwegian dentists, and the present investigation was undertaken to find out if the patterns of antibiotic prescription had changed since then.

MATERIAL AND METHODS

A total of 470 randomly selected dentists (10% of total) received a questionnaire and a letter describing the survey and 313 responded.

RESULTS

Results indicated that 35% did not issue any prescriptions in a typical week, while 3% issued > or =5. Fifty percent reported that they might prescribe antibiotics when treating periodontal diseases, but only 3.4% reported the use of microbial diagnosis before selecting an antibiotic; 71% of the respondents reported use of antibiotics occasionally to prevent general complications of dental treatment; 80% prescribed antibiotics for prophylactic use if the patient revealed a history of endocarditis, while 5% reported never doing so.

CONCLUSION

These findings are in concert with the results obtained 11 years ago, but indicating that dentists who had attended postgraduate courses on antibiotics prescribed such drugs more frequently. This was not statistically significant. However, it is of great concern that 5% never prescribed antibiotics when treating patients with a history of endocarditis, and that 20% did not know that amoxicillin was a penicillin. Such lack of knowledge may cause fatal results of therapy.

Intrafamilial Transmission of Black-pigmented, Putative Periodontal Pathogens

Porphyromonas gingivalis and Prevotella intermedia are black-pigmented, putative periodontopathogenic bacteria considered to cause some forms of periodontal disease. Porphyromonas gingivalis and P. intermedia can be transmitted between humans and produce periodontal disease in susceptible hosts. In this article, studies using molecular typing methods for determining the transmission of black-pigmented, putative periodontopathogens between family members are reviewed. As individuals living close to each other are more prone to transmit bacteria, the studies on transmission of periodontopathogens have been performed on family members. It has been shown that black-pigmented bacteria are not only transferred between spouses but also between parents and child. Since only a limited number of studies have been done, longitudinal and controlled studies should be carried out to elucidate further the transmittance potential of these bacteria.

Clinical and microbiological effects of adjunctive antibiotics in treatment of localized juvenile periodontitis. A controlled clinical trial

The aim of this study was to assess the clinical and microbiologic effects of the combination of amoxicillin and metronidazole therapy as an adjunct to mechanical treatment in the management of localized juvenile periodontitis. Twenty-five localized juvenile periodontitis (LJP) patients from a Brazilian population were randomly allocated into an experimental group receiving mechanical treatment and antibiotics, and a control group receiving mechanical treatment and placebo. Clinical and radiographic assessments, as well as microbiologic sampling for Actinobacillus actinomycetemcomitans, were performed at baseline and one year after the end of the treatment. At the termination of the study A. actinomycetemcomitans could be isolated from the oral cavity of all patients in the control group who harbored the bacterium at baseline and in 4 out of 8 patients in the experimental group. Both treatment modalities resulted in significant benefit on an individual basis. The experimental group, however, displayed better results than did the control group regarding gingival index (GI), probing depth (PD), clinical attachment level (CAL), and radiographic analysis of crestal alveolar bone mass, but not with respect to plaque index (PI). No serious adverse effects of the antibiotic treatment were observed in the present study.

The distribution and transmission of Actinobacillus actinomycetemcomitans in families with localized juvenile periodontitis

The prevalence and distribution of A. actinomycetemcomitans in families where at least one family member (proband) suffered from localized juvenile periodontitis was investigated. 25 probands with localized juvenile periodontitis (LJP) and their 78 close family members were screened for the presence of A. actinomycetemcomitans. Among these 25 families, 10 contained at least one additional family member colonized with oral A. actinomycetemcomitans. Genomic DNA from subgingival A. actinomycetemcomitans strains from each of the probands and their family members were amplified and characterized by the polymerase chain reaction (PCR) using a single primer known to distinguish A. actinomycetemcomitans strains. The PCR products from each strain were separated by electrophoresis on a 1% submarine agarose gel containing ethidium bromide and visualized by UV light transillumination. The studies showed that 41.2% of the parents and 58% of the siblings in this LJP-based population harbored the bacterium. Comparison of the PCR generated amplitypes showed that there was a wide distribution of amplitypes among the probands and immediate relatives. No clear transmission paths were observed in this specific population.

Attachment loss and serum antibody levels against autologous and reference strains of Actinobacillus actinomycetemcomitans in untreated localized juvenile periodontitis patients

Immunological data have been suggested to be a potential tool in the diagnosis, classification and monitoring of periodontal diseases. However, the role of circulating antibodies in periodontal patients is poorly understood. Patients suffering from localized juvenile periodontitis (LJP) are often reported to show high titers of serum IgG antibodies against Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans), but several affected patients do not. Most studies use well-known reference strains of the bacterium for testing against the patients' sera. The aim of the present investigation was to study the relationship between serum IgG antibody levels to autologous A. actinomycetemcomitans strains and clinical attachment loss (CAL). In addition, we wanted to assess the patients' serum titers against 4 well-known reference strains of the bacterium as well as their general potential immunoglobulin response. Intravenous blood samples were taken from 23 LJP patients and 10 healthy individuals, and autologous A. actinomycetemcomitans strains were cultured from 18 of the LJP patients. CAL was measured at 4 different sites around all present teeth and assessed as a % of teeth with at least 1 site moderately > or = 2 < 5 mm) or severely (> or = 5 mm) involved. An enzyme-linked immunosorbent assay (ELISA) was performed to evaluate the serum titers of IgG antibodies to A. actinomycetemcomitans antigens. No significant correlation was found between serum IgG antibody titers to autologous strains and CAL. However, there was a trend that low responders had more moderately affected teeth than had high responders and patients with undetectable A. actinomycetemcomitans levels, which is in agreement with a hypothetically protective role of the antibodies. The total counts of immunoglobulin assessed in all participants showed that the predominant class was IgG and the reference group displayed significantly less (p < 0.05) IgG and IgG1 counts than the LJP patients. Both the reaction pattern against reference and autologous strains varied widely. We conclude that the specific antibody response against A. actinomycetemcomitans shows a weak correlation to clinical attachment levels in LJP patients.

Localized juvenile periodontitis and Actinobacillus actinomycetemcomitans in a Brazilian population

Localized juvenile periodontitis (LJP) has been used as a model for studying periodontal disease, and its prevalence is considered to be higher in third-world countries (0.3-8%) than in industrialized countries (0.1%). Mostly, the disease has been associated with Actinobacillus actinomycetemcomitans (A.a.) but lack of association has also been reported. The aim of this study was to identify LJP patients in geographically different Brazilian populations and assess the presence of A.a. in their periodontal lesions. 7843 children, 12-19-years of age, from the cities of Rio de Janeiro, Votorantim and Belo Horizonte were screened, and LJP patients were identified by strict clinical and radiographical criteria. A final LJP prevalence of 0.3%, with a 99% confidence interval between 0.16% to 0.47%, was found. The prevalence in the subpopulations varied between 0.1-1.1% in the different areas. Subgingival bacterial samples were obtained from the oral cavity of 25 patients and their family members. 80% of these patients, 39.5% of their family members, 35.3% of their parents, and 43.9% of all siblings were culture positive for A.a. All but one of the families had at least one member in addition to the patient who was culture positive for A.a. In 3 families, > 1 member showed radiographic and clinical signs of LJP. 30% of non-LJP subjects coming from one of the areas with higher LJP prevalence harbored A.a. We conclude that LJP is highly associated with A.a. in this Brazilian population.

Microbiological and immunohistological findings in a patient with Papillon-Lefèvre syndrome

The following communication is a case history of an 11 year-old female patient suffering from Papillon-Lefèvre syndrome. Since a massive occurrence of A. actinomycetemcomitans had been found in the subgingival microflora of the periodontal pockets, the patient was treated with repeated subgingival scaling, with an adjunct Amoxicillin and Metronidazol treatment. A bacteriological examination of the girl's family proved that several brothers and sisters as well as one parent also carried. A. actinomycetemcomitans, showing 3 different strains of this bacterium within the family. An immunohistological examination of the gingival tissue showed a massive inflammatory infiltrate which was dominated by plasma cells. The histological investigation of the first molars did not show morphological abnormalities of the root cementum. Posttreatment clinical and radiographical improvement of the periodontal conditions is reported despite the recurrent finding of A. actinomycetemcomitans.

The natural history of periodontal disease. The correlation of selected microbiological parameters with disease severity in Sri Lankan tea workers

The purpose of this study was to assess the prevalence of A. actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia, and their association with periodontal disease states in a population sample from Sri Lanka. Based on clinical parameters, a total of 536 sites in 268 male Sri Lankan tea workers were categorized as healthy, or showing gingivitis only, moderate or advanced periodontitis. Bacterial samples were obtained from all sites and the three target bacteria identified by indirect immunofluorescence. P. intermedia, P. gingivalis and A. actinomycetemcomitans were found in 76%, 40% and 15% of the subjects, respectively. Of the 536 periodontal sites, 10.5% were categorized with "no disease", 14% "gingivitis only": 59% with moderate and 16% with advanced periodontitis. The prevalence of P. gingivalis and P. intermedia was significantly higher in sites with moderate and advanced periodontitis than in sites with no disease or gingivitis only. A. actinomycetemcomitans was not found in healthy sites, but occurred with equal frequency in sites with gingivitis, moderate and advanced periodontitis. The association between these three bacteria and periodontal diseases in Sri Lankan tea laborers was similar to that described for other non-industrialized and industrialized countries.

Bacterial resistance following subgingival and systemic administration of minocycline

The aim of the present study was to compare total numbers of cultivable bacteria and prevalence of resistance to minocycline among periodontal bacteria following subgingival or systemic application of minocycline in patients suffering from periodontal disease. 10 adult patients were administered 2% minocycline ointment subgingivally into their periodontal pockets at baseline, week 2 and months 1, 3, 6 and 9. Patients had scaling/root planing at baseline and month 6. In addition, 10 patients undergoing scaling/root planing followed by a 10-day course of systemic minocycline therapy, were studied and compared with the subgingival application group. Bacterial samples were taken from the 4 deepest pockets before each subgingival application of the drug. The systemic administration group was sampled at baseline and at week 2, as well as months 1 and 3 after completing the antibiotic treatment. For each patient at each sampling, bacterial samples were pooled, diluted, seeded on parallel blood agar plates and incubated aerobically and anerobically. After incubation, 30 colonies were picked at random and transferred to blood agar plates supplemented with 10 micrograms/ml minocycline, to estimate prevalence of minocycline-resistant bacteria. The results of this study indicate that subgingival application of minocycline ointment resulted in an initial reduction in total numbers of cultivable bacteria, which then remained depressed during the full year of the study. No such observation was made in the systemic administration. Both in the subgingival and the systemic administration group, the % of cultivable aerobic and anaerobic minocycline-resistant bacterial strains increased transiently following administration of the drug, but returned to baseline levels within 3 months post-treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Microbiologic tests in epidemiologic studies: are they reproducible?

Microbiologic assessments are often included in longitudinal studies to elucidate the significance of the association of certain Gram-negative bacteria and the development of periodontal diseases. In such studies, the reliability of methods is crucial. There are several methods to identify putative pathogens, and some of them are commercially available. The purpose of the present study was to compare the reproducibility of four different methods for detecting Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia in order to evaluate their usefulness in epidemiologic studies. The test panel consisted of 10 young subjects and 10 adult periodontitis patients. Subgingival plaque was sampled from sites showing bone loss and "healthy" control sites. The four different methods for detecting the target bacteria were 1) cultivation, 2) Evalusite (a chair-side kit based on ELISA), 3) OmniGene, Inc, based on DNA probes, and 4) indirect immunofluorescence (IIF). The test procedure was repeated after a 1-wk interval and was performed by one examiner. Sites reported to be positive for a microorganism by any of the four methods at one or both examinations were considered to be positive for that organism and included in the analysis. The reproducibility of the four methods was low. The IIF and the cultivation methods showed somewhat higher reproducibility than did the commercial systems. A second test was done for Evalusite, three paper points for sampling being used instead of one as described in the manual. The reproducibility of the second test was improved, indicating that the detection level of the system may influence the reliability.

Incidence of early periodontitis in a group of young individuals during 8 years: associations with selected potential predictors

The aim of the present study was to assess the incidence of early radiographic bone loss in a birth cohort over 8 years and to assess possible associations between incidence of bone loss and reported dental behavior, ethnic background, and previous orthodontic treatment. In a case control study comprising a proportion of the study population, the detection of black pigmented Bacteroides and Actinobacillus actinomycetemcomitans and their association with early radiographic bone loss was assessed. At the beginning of the study in 1984, there were 2,767 subjects. In 1992 sets of bite-wing radiographs were obtained from 215 subjects, who also filled out a questionnaire concerning their present and past dental behavior, ethnic background, and orthodontic treatment. Radiographic alveolar bone loss was recorded if the distance from the cemento-enamel junction to the alveolar crest exceeded 2 mm. Thirteen subjects (6%) showed new sites with bone loss over the 8-year period. Subgingival plaque was sampled from these 13 subjects and from 13 control subjects. None of the independent variables could be associated with the observed incidence of radiographic bone loss in this cohort, with the possible exception of the presence of A. actinomycetemcomitans which was detected in about 50% of the new sites with bone loss.

Prevalence and distribution of bacteriophage phi Aa DNA in strains of Actinobacillus actinomycetemcomitans

phi Aa is a bacteriophage that was originally isolated by induction of a lysogenic strain of the oral bacterium Actinobacillus actinomycetemcomitans. Since the discovery of phage phi Aa, additional phages infecting several other strains of A. actinomycetemcomitans have been identified. To determine the prevalence of phi Aa or phi Aa-related temperate phages in this species, a phi Aa-specific DNA probe was prepared to screen for homologous sequences among 42 strains of A. actinomycetemcomitans. Fourteen (33%) of the 42 strains examined contained DNA sequences that hybridized with the phage phi Aa probe. A bacteriophage designated phi Aa33384 was isolated by induction from one of the strains (ATCC 33384) that contained a sequence that hybridized with the phi Aa probe. The phi Aa probe hybridized with the DNA extracted from bacteriophage phi Aa33384. The distribution of the phage phi Aa sequence among A. actinomycetemcomitans serotypes was 5/13 (38%) of the serotype a strains, 0/16 (0%) of the serotype b strains, and 9/13 (69%) of the serotype c strains. The results of this investigation suggest that the target sequence prepared from the phage phi Aa genome is fairly common in the A. actinomycetemcomitans chromosome, and that the sequence is distributed among the A. actinomycetemcomitans serotypes in a seemingly nonrandom manner.

Use of a nonradioactive genetic probe identified, synthesized, and labeled in the polymerase chain reaction

This study introduces a strategy to identify and produce sequences useful as genetic markers, or native genetic probes for DNA-DNA hybridization in bacterial strains where the genetics is not well described. Actinobacillus actinomy-cetemcomitans (A.a.) was used as an example. Fifty ng genomic DNA from A.a. ATCC 33384 and Haemophilus aphrophilus ATCC 33389 was amplified in a thermocycler using a single 10-mer primer. The PCR products were separated by electrophoresis on a 1% submarine agarose gel containing ethidium bromide and visualized by UV illumination, and the strain-specific amplitypes were compared. DNA from two bands, 0.9 and 4 kb, unique for the A.a. strain, was cut out, amplified under high stringency with the same primer and labeled by replacing 33.3 microM dTTP with digoxigenin-labeled dUTP in the reaction mixture. The labeled probe was then repeatedly used for hybridization to DNA from various A.a., H. aphrophilus, and other bacterial strains of the Pasteurellaceae family. The results showed that the 0.9-kb probe detected all A.a. tested, and distinguished it from other closely related bacterial species. We conclude that the described strategy is useful for identifying and selecting genetic sequences useful as genetic markers in A.a.

Chlorhexidine use after two decades of over-the-counter availability

Chlorhexidine (CHX) is a compound with plaque-inhibiting effects and available only by prescription in the United States. In Norway, however, CHX has been dispensed over-the-counter for over 20 years, and this study was undertaken to evaluate dentists' perceptions regarding its indications, usefulness, and side effects. A written questionnaire was sent to a sample of 10% of dentists registered in Norway, 78% of whom (354) responded. Additionally, representatives from 2% of all dental practices in Norway were contacted by telephone. Fourteen percent (14%) of the respondents reported that they never recommended CHX to their patients. Among those recommending the compound, 85% used it frequently after surgical periodontal procedures; 74% when treating acute gingivitis; 57% following oral surgery in general; and 35% during non-surgical periodontal therapy. It was used also as an adjunct to other treatment routines. Seventy-three percent (73%) reported frequent use of CHX when treating stomatitis and 54% in herpes simplex infections. As to side effects, 77% of the dentists indicated that staining of teeth, restorations, and the tongue was a major concern to patients; 12% reported inconveniences due to the bitter taste; and 6% reported other disturbances such as dryness of the mouth and development of oral ulcerations. The majority (94%) of the dentists recommended mouth rinsing, whereas 6% recommended a gel form. Only 4% of the dentists recommended rinsing with a patient-diluted 0.1% concentration, whereas 96% recommended the standard 0.2% formulation; 88% recommended using CHX mouthwash twice a day or more often.(ABSTRACT TRUNCATED AT 250 WORDS)

The distribution and transmission of Actinobacillus actinomycetemcomitans in families with established adult periodontitis

The prevalence and genotype distribution of Actinobacillus actinomycetemcomitans strains in families where at least one adult family member (proband) suffered from periodontal disease was investigated to better understand how this periodontal organism is acquired or transmitted. Fifteen probands with severe (established) periodontal disease (EPD) and their 46 immediate family members were sampled for A. actinomycetemcomitans. Among the 15 families, 10 contained at least one additional family member colonized with oral A. actinomycetemcomitans. Genomic DNA from 3 subgingival A. actinomycetemcomitans strains from each of the 10 probands and their 17 family members were amplified and characterized by the polymerase chain reaction (PCR) using a single arbitrary primer known to distinguish A. actinomycetemcomitans strains. The PCR products from each strain were separated by electrophoresis on a 1% submarine agarose gel containing ethidium bromide and visualized by UV light transillumination. The amplification products migrated to form readily distinguishable bands and, since the banding patterns were characteristic of strains of A. actinomycetemcomitans, these patterns were called "amplitypes." The culture studies showed that 51% of all patients suffering from EPD carried oral A. actinomycetemcomitans. Moreover, 50% of their spouses and 30% of their children harbored the bacterium. Comparison of the PCR-generated amplitypes showed that 26 out of 27 individuals had strains exhibiting a single amplitype of A. actinomycetemcomitans, the 27th being colonized by 2 different amplitypes. They also showed that in 6 out of 7 families, the husband and wife did not harbor the same A. actinomycetemcomitans amplitype. Furthermore, most often children carried an an amplitype identical to one of the parents.(ABSTRACT TRUNCATED AT 250 WORDS)

Differentiation of strains of Actinobacillus actinomycetemcomitans by arbitrarily primed polymerase chain reaction

The present study describes a method for amplifying DNA in Actinobacillus actinomycetemcomitans by using short, synthetic oligonucleotides of random sequence as primers in the polymerase chain reaction. Genomic DNA from each of 20 human isolates of A. actinomycetemcomitans was successfully amplified in a thermal cycler with a single synthetic primer (GGGTAACGCC) and reproducibly produced 14 different DNA amplification profiles (amplitypes). A. actinomycetemcomitans isolates from the same subject revealed the same amplitype. The arbitrarily primed polymerase chain reaction appears to be useful in characterizing human isolates of A. actinomycetemcomitans for studies of epidemiology and bacterial transmission.

Prevention of transmission of resistant bacteria between periodontal sites during subgingival application of antibiotics

This study was designed to investigate whether antibiotic resistant micro-organisms are able to contaminate and survive on syringe tips used for subgingival deposition of antibiotics, and to test simple and effective means of disinfecting the syringe tip between applications. In the first part of the study, syringe tips used for application of Minocycline subgingival formula in 20 adult periodontitis patients were cultured for bacteria resistant to this drug before and after disinfecting them with ethanol. The results showed that 80% of the unwashed syringes were culture positive for minocycline resistant bacteria, whereas only 1 ethanol washed syringe tip was contaminated. In part II of the study, after dispensing minocycline periodontal formula in 20 patients, 10 of the syringe tips were washed with ethanol while 10 were left untreated. All syringes were stored in a refrigerator for 8 days, whereafter the tips were sampled for resistant bacteria. 20% of the unwashed tips were contaminated after 8 days incubation at 4 degrees C. None of the ethanol washed syringe tips were culture positive. We conclude that syringe tips may be contaminated with antibiotic resistant bacteria after dispensing the antibiotic in periodontal pockets. The transmission of these bacteria to other periodontal sites may be avoided by disinfecting the syringe tip with ethanol between applications. We have also shown that antibiotic resistant bacteria may survive on the syringe tip following 8 days storage in a refrigerator, suggesting that syringes used for subgingival deposition of an antibiotic should not be stored for reuse.

Rapid identification of Actinobacillus actinomycetemcomitans based on analysis of 23S ribosomal RNA

Actinobacillus actinomycetemcomitans is a key microorganism in the pathogenesis of several different forms of periodontal diseases. Identification of this bacterium from clinical specimens may often be complicated by the fact that the colony morphology on TSBV selective medium closely resembles that of Haemophilus aphrophilus and a key differentiating characteristic, catalase reaction, may be variable. Recent genetic studies have shown that the 23S ribosomal RNA molecule is split into two smaller forms in A. actinomycetemcomitans, but is intact in H. aphrophilus. Based on this finding, we describe a new, rapid method for identifying A. actinomycetemcomitans in which single colonies isolated from culture on TSBV agar in 5% CO2 in air are lysed, electrophoresed on 1.5% submarine agarose gels and visualized by staining with ethidium bromide. Using this assay, A. actinomycetemcomitans can be easily distinguished from morphologically similar colonies such as H. aphrophilus strains by differences in 23S rRNA within 2 h.

Entrance of Actinobacillus actinomycetemcomitans into HEp-2 cells in vitro

A strain of actinobacillus actinomycetemcomitans, freshly isolated from a juvenile periodontitis patient, and the FDC Y4 laboratory strain of Aa were tested for their capacity to adhere to and enter the epithelial cell line HEp-2 cells in vitro. Immunofluorescence microscopy as well as scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that both strains adhered to the outer surface of the HEp-2 cells. In the TEM studies, the specimens were also treated with Aa specific antibodies and gold labeled protein A. These examinations showed that only the freshly isolated strain of Aa was found within the HEp-2 cells. The intracellular Aa were found to be viable, and in one case one of them was seen to undergo division. It is concluded that freshly isolated Aa has the ability to enter epithelial HEp-2 cells in vitro, and it is tentatively suggested that this may play a role in the pathogenesis of periodontal disease.

Antibiotic prescribing practices among Norwegian dentists

There is scarce information on antibiotics prescription habits among dentists in general. The present investigation was undertaken to study some patterns of antibiotics prescription among Norwegian dentists. A total of 459 dentists (approximately 10% of Norwegian dentists) were randomly selected, and to each was mailed a letter describing the survey, accompanied by a questionnaire about age, type of practice, educational background and pattern of prescription of antibiotics. 78% of the dentists responded to these questions. The results indicate that during a typical week, 32% did not prescribe antibiotics, whereas 5% wrote greater than 5 prescriptions. The mean weekly number of prescriptions per dentist was 2.04. Periodontists and oral surgeons prescribed antibiotics significantly more often than did general practitioners and other disciplines. In addition, those with research and/or teaching experience seemed to prescribe significantly more often than those without. More than 1/3 of the sample indicated that they may prescribe antibiotics when treating periodontal diseases. Compared with other disciplines, periodontists prescribed such drugs significantly more often when treating periodontitis, but significantly less often in acute gingivitis, stomatitis and herpes simplex infections. Moreover, 22% of the dentists might prescribe antibiotics when the patient is in pain, 73 and 38% in cases of abscesses with or without generalized malaise, 2.5% in endodontic therapy, 60% to prevent general complications, and 68% for prophylactic use if the patient revealed a history of endocarditis. Norwegian dentists are somewhat restrictive in their prescription of antibiotics, but they mostly prescribe the correct drugs for the different conditions.

Association between detection of oral Actinobacillus actinomycetemcomitans and radiographic bone loss in teenagers. A 4-year longitudinal study

The aim of the present study was to assess a possible association between radiographic bone loss and presence of Actinobacillus actinomycetemcomitans on the site and subject level over time. Forty-six teenagers with registered radiographic bone loss and 8 controls participated in the study, which began in 1984. In 1986 and 1988 new sets of bite-wing radiographs were obtained and examined for bone loss. Subgingival plaque was sampled from both diseased and contralateral healthy sites in the same individual. Only 15 of the 46 originally diseased sites persisted with bone loss in 1986, and 60% of these sites harbored A. actinomycetemcomitans. Of the 31 "healed" sites, 29% contained A. actinomycetemcomitans. The difference was statistically significant at P less than 0.05. Six of the contralateral healthy sites had developed bone loss during these 2 years and 50% of them contained A. actinomycetemcomitans, while 35% of the remaining contralateral sites harbored A. actinomycetemcomitans. The difference was not statistically significant (P greater than 0.05). The difference between patients with and without persistent bone loss regarding presence of A. actinomycetemcomitans was statistically significant in 1986; however, none of the observed differences were statistically significant in 1988. A. actinomycetemcomitans was found 2 to 3 times more frequently in patients with radiographic bone loss at all examinations than in "healthy" subjects. Detection of A. actinomycetemcomitans on the site level appeared to be a poor predictor of future radiographic bone loss.

Invasive growth of Actinobacillus actinomycetemcomitans on solid medium (TSBV)

When grown on agar, most Actinobacillus actinomycetemcomitans form circular and convex colonies with an internal star-shaped morphology. Such colonies adhere firmly to the agar, and when removed, a star-shaped imprint similar to that of the intact colony remains. This study was undertaken to determine the nature of this in vitro growth. Stereo-microscopy and scanning and transmission electron microscopy showed that the star-shaped imprint of A. actinomycetemcomitans colonies reflected pseudopod-like extensions of the bacterial colony which penetrated deep into the TSBV agar. The center of the colonies consisted primarily of ghost-like cells, while the dense border of each colony, including the pseudopods, expressed characteristics of vital cells. The latter were embedded in vast amounts of extracellular vesicles, and the outer aspect of the pseudopods was lined with a border of such vesicles.

Outer membrane proteins of Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus studied by SDS-PAGE and immunoblotting

This investigation characterized and compared outer membrane proteins (OMP) of the closely related Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus by means of SDS-PAGE patterns and reactions on immunoblots with rabbit antiserum against A. actinomycetemcomitans FDC Y4. Reactions with serum from a patient with Papillon Lefévre syndrome (PLS), from whom periodontal wild strains of A. actinomycetemcomitans had been isolated, were also studied. OMP were purified with selective solubilization from lyophilized cells of 10 wild and 4 reference strains of A. actinomycetemcomitans and 4 reference strains of H. aphrophilus. OMP profiles from wild and reference strains of A. actinomycetemcomitans were similar while those from A. actinomycetemcomitans and H. aphrophilus differed. The most prominent difference was absence of a heat modifiable protein in H. aphrophilus strains. Immunoblotting revealed strong common antigens in most strains, including a heat modifiable protein with mol wt 34 kDa, as well as a 29 kDa and a 16.5 kDa protein. Treatment with pronase and sodium periodate confirmed the protein nature of the major OMP antigens.

Plasmids in Actinobacillus actinomycetemcomitans strains isolated from periodontal lesions of patients with rapidly destructive periodontitis

Several strains of Actinobacillus actinomycetemcomitans newly isolated from periodontal lesions of patients with rapidly destructive periodontitis were all shown to possess identical plasmid profiles consisting of 4 plasmids. The largest plasmid, 20 MegaDalton (MDa), was also found in reference strains. Two different methods were used for isolation of the plasmids; the large 20 MDa plasmid (pHRP1) was found using the Kado and Liu method only. The 3 small plasmids of 7.0, 5.2 and 4.0 MDa (pHRP2, pHRP3, pHRP4), respectively, were seen using the Birnboim and Doly method. These plasmids are so far to be regarded as cryptic; no phenotypical characters have been linked to their presence. The large 20 MDa plasmid was found in all strains examined, and may be a genotypical marker for the A. actinomycetemcomitans species.

Treatment of rapidly destructive periodontitis in Papillon-Lefèvre syndrome. Laboratory and clinical observations

This paper reports the successful treatment of the periodontal component of the Papillon-Lefèvre syndrome in 2 siblings. Treatment consisted of extractions of periodontally-involved teeth under antibiotic therapy. The exogenous source of the suspected pathogenic A. actinomycetemcomitans in this family, identified as a pet dog, was also treated with antibiotics. Assessments of monocyte function and levels of serum antibodies against A. actinomycetemcomitans were performed prior to an immediately after treatment. Microbiological screening of subgingival dental plaque of the PLS patients as well as the rest of the household members, including the dog, was performed every month during the study period. Remission of the rapidly destructive periodontitis, as well as an earlier-described monocyte dysfunction in these two PLS patients occurred concomitantly with the eradication of A. actinomycetemcomitans from the family. 15 months after this treatment, the children still had no signs of periodontitis or of A. actinomycetemcomitans infection. The legitimacy with which PLS is defined as a disease entity is discussed and questioned.

The presence of phage-infected Actinobacillus actinomycetemcomitans in localized juvenile periodontitis patients

Electron microscopy revealed 2 different types of bacteriophages isolated from Actinobacillus actinomycetemcomitans colonizing exclusively diseased sites in 4 patients with localized juvenile periodontitis (LJP). All sites infected with phage were undergoing periodontal destruction, as judged from consecutive routine radiographs. The phages isolated had a wide host range as assessed from their ability to infect a series of reference strains of A. actinomycetemcomitans. A 5th patient harboured non-infected A. actinomycetemcomitans in a surgically treated site which had undergone no bone destruction during the last 12 months. The present findings suggested that the pathogenic potential of A. actinomycetemcomitans in LJP may increase due to phage infection.