Refractory periodontitis: critical questions in clinical management

Triptolide mitigates the inhibition of osteogenesis induced by TNF-α in human periodontal ligament stem cells via the p-IκBα/NF-κB signaling pathway: an in-vitro study

BACKGROUND

Triptolide is a widely utilized natural anti-inflammatory drug in clinical practice. Aim of this study was to evaluate effects of triptolide on hPDLSCs osteogenesis in an inflammatory setting and to investigate underlying mechanisms.

METHODS

Using the tissue block method to obtain hPDLSCs from extracted premolar or third molar. Flow cytometry, osteogenic and adipogenic induction were carried out in order to characterise the features of the cells acquired. hPDLSC proliferative activity was assessed by CCK-8 assay to determine the effect of TNF-α and/or triptolide. The impact of triptolide on the osteogenic differentiation of hPDLSCs was investigated by ALP staining and quantification. Osteogenesis-associated genes and proteins expression level were assessed through PCR and Western blotting assay. Finally, BAY-117,082 was used to study the NF-κB pathway.

RESULTS

In the group treated with TNF-α, there was an elevation in inflammation levels while osteogenic ability and the expression of both osteogenesis-associated genes and proteins decreased. In the group co-treated with TNF-α and triptolide, inflammation levels were reduced and osteogenic ability as well as the expression of both osteogenesis-associated genes and proteins were enhanced. At the end of the experiment, both triptolide and BAY-117,082 exerted similar inhibitory effects on the NF-κB pathway.

CONCLUSION

The osteogenic inhibition of hPDLSCs by TNF-α can be alleviated through triptolide, with the involvement of the p-IκBα/NF-κB pathway in this mechanism.

An In Vitro Pilot Study on the Effects of Silver Diamine Fluoride on Periodontal Pathogens and Three-Dimensional Scaffolds of Human Fibroblasts and Epithelial Cells

Objective

The aims of this study were to investigate the antibacterial and cytotoxic effects of silver diamine fluoride (SDF) on periodontal pathogens and human skin constructs, respectively.

Background

SDF has been proven to have bactericidal effects on cariogenic bacteria. No studies to date evaluated the bactericidal effects of SDF on periodontal pathogens nor its effect on epithelium and fibroblasts.

Methods

Streptococcus mutans, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans were cultured in monospecies biofilms, exposed to increasing concentrations of SDF and inoculated on agar plates to assess viability. Human gingival fibroblasts in 2D cultures were exposed to 1 μL of 0.394% of SDF and viewed using real-time imaging. Finally, SDF was applied to human, 3D tissue scaffolds of fibroblasts and keratinocytes, and termed human skin equivalents (HSE). A clinical dose of 38% SDF was applied, and HSE were cultured for 12 hours, 1, 3, 5, and 10 days. The tissue was observed clinically and histologically with hematoxylin and eosin staining and TUNEL.

Results

S. mutans and A. actinomycetemcomitans growth was completely inhibited using all dilutions of SDF, whereas P. gingivalis was still viable with 0.197% and 0.098% of SDF. Single-layer fibroblasts experienced immediate necrosis upon contact with SDF. Application of SDF to HSE showed maturation of a whitish lesion within 24 hours, followed by pigmented, crusted tissue after 3 days. Histological evaluation of treated tissues showed apoptotic cells in the epithelium and upper half of the connective tissue.

Conclusion

Our data suggest that SDF has bactericidal properties against two periodontal pathogens: P. gingivalis and A. actinomycetemcomitans. SDF caused immediate necrosis of monolayer fibroblasts, but does not extend to the full extent of layered fibroblasts in HSE.

Applications of Lasers in Refractory Periodontitis: A Narrative Review

Objective:

The purpose of the study is to evaluate the various lasers in dentistry and to investigate if it can be used for treatment of refractory periodontitis.

Methods:

The study followed partially the PRISMA guidelines as it is a narrative review. A number of articles were selected from a period of 1980 to 2020 from databases, PubMed, PubMed central, Cochrane and Scopus. Articles related to the effects of lasers on periodontitis both refractory and aggressive were investigated.

Results:

After reviewing the literature, 70 articles were found, related to application of lasers in periodontal diseases. Out of the 70, 11 articles pertained to the effect of laser for the treatment of Refractory and inflammatory periodontitis. 5 articles related to experimental animal models, one pertaining to in-vitro and six studies related to in-vivo in human cohorts.

Discussion:

It was found that lasers if used in controlled parameters by incorporating laser assisted treatment such as Photodynamic therapy and low level laser therapy can be of use as an adjunct therapy for treatment of refractory periodontitis. The use of different wavelengths in the initial and maintenance phase of periodontal disease plays a positive role. The presence of in-vitro and animal model studies is one of the limitation to this study. The available studies have shown marked reduction in inflammation and better clinical and microbiological parameters. The drawback of this study is the limited literature involving laser management for refractory periodontitis in human cohorts.

Conclusion:

Different wavelengths of laser and choice of laser assisted periodontal treatment plays an important role in the overall progress and prognosis of periodontal disease activity.

Clinical and Biological Effects of Adjunctive Photodynamic Therapy in Refractory Periodontitis

Introduction: To date, no novel treatment approach is available for optimum outcomes regarding refractory periodontitis. The aim of the present study was to assess the efficiency of photodynamic therapy (PDT) in treating patients diagnosed with refractory periodontitis and compare the clinical and biological outcomes of conventional periodontal treatment with or without adjunctive PDT in these patients, by assessing clinical parameters (plaque index [PI], gingival recession [GR], bleeding on probing [BOP], periodontal probing depth [PPD] and clinical attachment level [CAL]) as well as biological parameters (IL-1β) in the gingival crevicular fluid (GCF). Methods: Sixteen patients within the age of 30 to 60 years, with a mean age of 40 years old, diagnosed with refractory periodontitis were included. In this split mouth design study, 2 quads (1 upper + 1 lower) from the same patient were randomly treated with (scaling and root planing [SRP]+PDT) together. The other 2 quadrants (1 upper + 1 lower) were treated by SRP only and selected to serve as controls. Clinical parameters including PI, GR, BOP, PPD and CAL and biological parameters (IL-1β) in the GCF were measured at baseline, then at, 2 and 6 months after therapy. Results: A statistically significant reduction in several clinical parameters as, BOP (P < 0.001), PI (P < 0.001), PPD (P < 0.001) and CAL (P < 0.001) in quadrant treated with SRP and adjunctive PDT when compared to control group treated with SRP alone was observed and both therapies showed non-statistically significant differences in the reduction of IL-1β level. Conclusion: The inclusion of PDT as an adjunctive measure to nonsurgical conventional periodontal treatment seems to be a useful therapeutic measure in refractory periodontitis treatment.

The use of systemic antibiotics in the treatment of refractory periodontitis: A systematic review

BACKGROUND

The goal in treating refractory periodontitis (RP) is to arrest or slow disease progression, which usually has included the use of systemic antibiotics adjunct to conventional mechanical debridement. The aim of this systematic review was to evaluate the evidence that the association of systemic antibiotics with conventional mechanical debridement increases the efficacy of periodontal therapy in the treatment of RP.

TYPES OF STUDIES REVIEWED

The authors searched for studies in PubMed MEDLINE, Cochrane Central Register of Controlled Trials, Thomson Reuters Web of Science, Scopus, Latin American and Caribbean Center on Health Sciences Information, and Scientific Electronic Library Online electronic databases by using selected key words from the earliest records up through October 31, 2014. Only clinical intervention studies in which investigators compared the treatment of participants with RP with either mechanical debridement alone or associated with systemic antibiotics were eligible for selection. Two authors independently assessed the risk of bias of each selected study.

RESULTS

The authors identified 13 articles and included 6 of them. Investigators in all studies reported greater reductions in probing depth or in loss of clinical attachment level after adjunct systemic antibiotic therapy when compared with mechanical debridement alone. Antibiotics tested included metronidazole, clindamycin, tetracycline hydrochloride, amoxicillin, and amoxicillin and potassium clavulanate. Five studies presented a high risk of bias, and 1 study presented an unclear risk.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

The overall quality of the evidence does not allow the conclusion that adjunct systemic antibiotics are of additional benefit to conventional mechanical debridement alone.

Periodontitis: a host-mediated disruption of microbial homeostasis. Unlearning learned concepts

New concepts evolve when existing ones fail to address known factors adequately or are invalidated by new evidence. For decades periodontitis has been considered to be caused by specific bacteria or groups of bacteria and, accordingly, treatment protocols have largely been based on anti-infective therapies. However, close inspection of current data leads one to question whether these bacteria are the cause or the result of periodontitis. Good evidence is emerging to suggest that it is indeed the host response to oral bacteria that leads to the tissue changes noted in gingivitis. These changes lead to an altered subgingival environment that favors the emergence of 'periodontal pathogens' and the subsequent development of periodontitis if the genetic and external environmental conditions are favorable for disease development. Thus, it seems that it is indeed the initial early host-inflammatory and immune responses occurring during the development of gingivitis, and not specific bacteria or their so-called virulence factors, which determine whether periodontitis develops and progresses. In this review we consider these concepts and their potential to change the way in which we view and manage the inflammatory periodontal diseases.

Application of chitosan gel in the treatment of chronic periodontitis

Local administration of antibiotics in periodontal therapy can be provided with an appropriate delivery system. The purpose of this study was to evaluate the clinical effectiveness of chitosan, both as a carrier in gel form and as an active agent in the treatment of chronic periodontitis (CP). The chitosan gel (1% w/w) incorporated with or without 15% metronidazole was prepared and applied adjunctive to scaling and root planing (SRP) in comparison to SRP alone (control group-C), in CP patients. The clinical parameters such as probing depth (PD), clinical attachment level, the amount of gingival recession, plaque index, gingival index, and gingival bleeding time index were recorded at baseline and at weeks 6, 12, and 24. In all groups, significant improvements were observed in clinical parameters between baseline and week 24 (p < 0.05). The reductions in PD values were 1.21 mm for Ch, 1.48 mm for Ch + M, and 0.94 mm for C groups. No complications related to the chitosan were observed in patients throughout the study period. It is suggested that chitosan itself is effective as well as its combination with metronidazole in CP treatment due to its antimicrobial properties.

The gene expression profile in refractory periodontitis patients

BACKGROUND

There are no specific bacterial profiles or diagnostic tests capable of identifying refractory periodontitis patients before a treatment regimen is initiated. Therefore, in this high-risk cohort of patients who do not respond appropriately, host factors that might be partly under genetic control may play a crucial role in their susceptibility. Specifically, we tested the hypothesis that patients with refractory periodontitis have multiple upregulated and/or downregulated genes that might be important in influencing clinical risk.

METHODS

Oral subepithelial connective tissues were harvested aseptically from seven refractory periodontitis and seven periodontally well-maintained patients. An RNA isolation kit was used to isolate total RNA from tissue samples that had been stabilized in the RNA stabilizing reagent. The isolated total RNA was then subjected to gene expression profiling using the microarray to measure gene expression levels. The retrieved data were analyzed with a computer program for the differential analysis of gene expression microarray experiments. In addition, real-time polymerase chain reaction (PCR) analysis was performed on selected samples to confirm the microarray data's gene expression patterns.

RESULTS

A total of 68 upregulated and six downregulated genes were identified that were differentially expressed at least two-fold out of 22,283 genes we analyzed. The selected model provided a 93% intrinsic validation along with a 93% extrinsic validation. To validate the microarray data, five upregulated genes (lactotransferrin [LTF], matrix metalloproteinase-1 [MMP-1], MMP-3, interferon induced-15 [IFI-15], and Homo sapiens hypothetical protein MGC5566) and two downregulated genes (keratin 2A [KRT2A] and desmocollin-1 [DSC-1]) were randomly selected for further analysis by real-time PCR. The relative RNA expression level of these genes measured by real-time PCR was similar to those measured by microarrays.

CONCLUSION

The combined use of microarray technology with the computer program for the differential analysis of gene expression microarray experiments provided a set of candidate genes that may serve as novel therapeutic intervention points and improved diagnostic and screening procedures for high-risk individuals.

Debridement and local application of tetracycline-loaded fibres in the management of persistent periodontitis: results after 12 months

BACKGROUNDS/AIMS

The aim of our study was to evaluate the clinical, radiological and microbiological response to the local delivery of tetracycline (TE) of sites with persistent periodontal lesions.

MATERIALS AND METHODS

The study was conducted in a split-mouth design. Nineteen patients with at least four bilateral pockets 4-5 mm and bleeding on probing (BOP) were treated with scaling and root planing (SRP) plus TE fibres (test sites) or with SRP alone (control sites). Clinical and radiological measurements were taken at baseline, 6 months and 12 months post-operatively. Subgingival plaque samples were collected at baseline, at fibres removal, 6 and 12 months following treatment and analysed by polymerase chain reaction.

RESULTS

Both treatments yielded a statistically significant (p<0.05) reduction of probing depth (2.05 and 1.21 mm), gain of clinical attachment level (1.71 and 0.53 mm) and reduction of BOP scores (23.68% and 57.89%) for TE and SRP groups, respectively, when comparing 12-month data with baseline. The differences between two groups were significant. The prevalence of Treponema denticola and Bacteroides forsythus decreased after therapy in both groups but only in the test sites Actinobacillus actinomycetemcomitans and Prevotella intermedia were not yield detected. The pathogens could be eliminated from five periodontal pockets by SRP alone, while 21 TE sites were not recolonized at 12 months.

CONCLUSIONS

SRP plus TE fibres gave the greatest advantage in the treatment of periodontal persistent lesions at least 12 months following treatment.

Adjunctive benefits of subantimicrobial dose doxycycline in the management of severe, generalized, chronic periodontitis

BACKGROUND

Severe, generalized periodontitis is a form of chronic periodontitis that appears to be associated with an exaggerated host response. Little information is available on the benefits of using adjunctive host modulation in the management of this form of periodontal disease.

METHODS

Thirty subjects < or = 45 years of age with severe, generalized periodontitis received subgingival debridement and oral hygiene instructions each week for 4 weeks, plus 6 months of adjunctive subantimicrobial doxycycline (SDD) or placebo. Periodontal status was monitored at baseline, and at 1, 3, 5.25, and 8.25 months following completion of the hygiene sessions. Maintenance therapy was performed at 3, 5.25, and 8.25 months for both groups.

RESULTS

Ten subjects in each group completed all phases of the study. Subgingival debridement plus adjunctive SDD reduced deep pockets (> or =7 mm at baseline) by an average of 3.02 mm after 9 months versus 1.42 mm for the placebo group. A significant clinical response was seen in both groups as soon as 1 month, but the response was always clinically and statistically greater in the SDD group. In the SDD group, nearly 40% of 237 pockets > or =7 mm were reduced by > or =4 mm, and 55% were reduced by > or =3 mm. In addition, only 2 pockets deepened by > or =4 mm in the SDD group versus 10 in the placebo group.

CONCLUSIONS

The supplementation of hygienist-delivered full mouth subgingival and supragingival debridement with a host-modulating agent, SDD, provides clinically and statistically significant benefits in the reduction of deep pockets in patients with severe, generalized periodontitis. In addition, adjunctive SDD is more effective than a placebo in preventing further increases in probing depth.

Bone mineral content and bone metabolism in young adults with severe periodontitis

OBJECTIVES

To clarify in young adults with severe periodontitis (1) whether the bone mineral content (BMC) or density (BMD) in the mandible/other skeletal sites and the systemic bone metabolism differed from normal and (2) whether mandibular/forearm BMC did change during the 5 to 10-year follow-up.

MATERIAL AND METHODS

24 young otherwise normal patients with verified severe periodontitis were included, of which 20 attended the follow-up visit. Mandibular/forearm BMC was measured at both visits by dual-photon absorptiometry, supplemented with femoral neck/lumbar spine BMD measurements at follow-up visit by dual-energy X-ray absorptiometry. Serum alkaline phosphatase/ionized calcium, urinary excretion of pyridinoline/deoxy-pyridinoline were analysed at the follow-up visit. A conventional periodontal examination was performed at both visits.

RESULTS

Mandibular BMC was significantly below normal mean BMC at both visits. The mandibular Z-scores were < or = -2.00 in 33.3% (8/24). BMC/BMD in the remaining sites and the values for bone markers did not differ from normal. Mandibular/forearm BMC was stable while a significant aggravation of alveolar bone loss occurred during the trial without change of probing depth.

CONCLUSIONS

Severe periodontitis in young adults seems to be a local disorder associated with relatively low BMC in the jaws without systemic alterations of BMC/BMD and bone metabolism.

The effect of systemic antibiotics in the treatment of patients with recurrent periodontitis

BACKGROUND

Subjects with periodontal disease exist who either (i) respond poorly to initial mechanical therapy ("refractory" periodontitis) or (ii) fail to adopt adequate self-performed plaque control techniques and hence develop recurrent disease ("recurrent" periodontitis) at multiple sites during the supportive treatment phase (SPT). Various systemic antibiotic regimens have been tried as adjuncts to the mechanical (re-) treatment of such "difficult to treat"-patients. While most studies indicated a positive outcome of the adjunctive therapy, some clinical investigators reported that this additional measure provided little or no benefit.

AIM

The aim of the present investigation was to study the more long term effect of adjunctive antibiotic therapy in the re-treatment of patients with a well defined history of recurrent periodontitis.

MATERIAL AND METHODS

17 subjects with recurrent advanced periodontal disease were, following a baseline examination, subjected to non-surgical therapy including the use of systemic antibiotics (amoxicillin and metronidazole). They were placed in a careful SPT program and re-examined after 1, 3 and 5 years. The examinations included both clinical and microbiological assessments.

RESULTS

It was demonstrated that in subjects with advanced and recurrent periodontitis, re-treatment including (i) comprehensive scaling and root planing (SRP), (ii) systemic administration of antibiotics and (iii) meticulous supragingival plaque control by both mechanical and chemical means established periodontal conditions that in the short term (3 years) and in the majority of subjects could be properly maintained by traditional SPT measures. Between 3 and 5 years, however, only 5 of the 17 subjects exhibited stable periodontal attachment levels.

CONCLUSIONS

Some deep pockets and furcations were most likely inadequately instrumented during the active treatment phase. Microorganisms residing in biofilms left in such locations were probably not sufficiently affected by the 2 weeks of adjunctive antibiotic therapy. It is suggested that removal of certain subgingival deposits, therefore, may require surgical intervention.

Porphyromonas gingivalis-specific IgG subclass antibody levels as immunological risk indicators of periodontal bone loss

BACKGROUND

It has been well demonstrated a positive association between the magnitude of host antibody response and periodontal disease status. Previous studies also reported that Porphyromonas gingivalis-specific IgG subclass antibodies were elevated in sera from adult periodontitis patients. However, the rôle and the association of these IgG subclass antibodies to the development of periodontal diseases are poorly understood.

AIM

The aim of present investigation was to examine the relation of serum IgG subclass antibody levels and alveolar bone loss in treated and untreated periodontitis patients.

METHODS

Serum samples were taken from 20 treated and maintained periodontitis patients (SPT patients), 30 untreated patients and 19 periodontally healthy subjects. We determined the IgG subclass antibody titers to P. gingivalis whole cells using an enzyme-linked immunosorbent assay (ELISA). Subgingival plaque samples were taken from the mesio-buccal surface of 6 randomly selected teeth of SPT patients and evaluated for the presence of P. gingivalis by immunofluorescence microscopy. Clinical measurements were also taken including full mouth intraoral radiographs to measure interproximal alveolar bone loss at baseline (BLS1) and at a 5-year recall visit in the SPT patients (BLS2).

RESULTS

Our results indicated that both patient groups had detectable levels of IgG1, IgG2, and IgG4. Significantly higher IgG1 was observed in both patient groups compared to the healthy subjects. The untreated patients also exhibited significantly elevated IgG2 response (p<0.05). The mean IgG4 level of the SPT patients was significantly higher compared to the other subject group (p<0.05). A statistically significant positive correlation between IgG2 levels and changes in bone levels (DeltaBLS: BLS2-BLS1) was seen in the SPT patients (p<0.001). SPT patients with high IgG2 and low IgG4 showed greater bone loss than those with low IgG2 and high IgG4 (p<0.05), although the mean prevalence of P. gingivalis in the 2 groups did not differ significantly.

CONCLUSION

Our data suggest that the prolonged IgG2 response after periodontal treatment may be indicative of recurrent or persistent periodontal destruction.

Advances in periodontology

Advances in periodontal science and practice over the last decade have radically changed the understanding of periodontal diseases and have opened new, exciting prospects for both medical and surgical therapy of periodontal diseases. Establishment of the aetiology and pathogenesis of periodontitis, understanding of the unique genetic and environmental susceptibility profile of affected subjects, and recognition of the systemic implications of periodontal infections are the key research findings. The use of randomised, controlled, clinical trials has allowed the development of evidence-based periodontology. Adjunctive antimicrobial therapy, regenerative periodontal surgery, periodontal plastic surgery, bone regeneration surgery in the light of implant treatment, and advanced soft tissue management at implant sites have radically changed practice.

A practical approach to the diagnosis and treatment of periodontal disease

BACKGROUND

Both nonsurgical and surgical periodontal therapies are important in the control of most forms of periodontal disease. Sometimes, nonsurgical therapy is adequate to control the disease in mild cases and to slow progression and maintain periodontal stability in more advanced cases. Other times, both therapies may be indicated to obtain satisfactory results. The author presents treatment guidelines and recommendations for periodontal therapy.

METHODS

The author searched the dental literature for information pertaining to periodontal therapy.

RESULTS

The author found evidence-based data to support the effectiveness of nonsurgical and surgical periodontal therapy in controlling periodontal disease. Nonsurgical periodontal therapy requires time, effort, and good diagnostic and clinical skills to obtain satisfactory results. The results are determined by evaluating the patient's periodontal disease after active therapy, at which time additional surgical or nonsurgical treatment may be recommended. Evaluation should continue throughout the lifelong supportive phase of periodontal therapy.

CONCLUSION

Clinicians should continue to develop and enhance their diagnostic skills, assess factors that affect diagnosis and prognosis, formulate a comprehensive treatment plan, render appropriate treatment, evaluate the outcome and determine when periodontal care is indicated.

CLINICAL IMPLICATION

Failure to comply with monitoring the patient's periodontal status may lead to uncontrolled disease and eventually premature tooth loss. Premature tooth loss can be prevented through patient education and application of evidence-based nonsurgical and surgical therapy.

Local delivery of tetracycline: from concept to clinical application

This manuscript reviews the development over the last 20 years of the evidence supporting the clinical application of a controlled delivery device for the treatment of human periodontitis. The device is a monolithic ethylene vinyl-acetate fibre loaded with 25% w/w tetracycline HCI (tetracycline fibre). It releases tetracycline at a steady state rate of 2 microg/cm x h and results in the maintenance of essentially constant, highly-effective concentrations of tetracycline at the site of action. A series of controlled, randomised, single-blind, phase-III clinical trials including a total of 463 patients has indicated that: (1) tetracycline fibres result in significantly better outcomes than the scaling and root planing positive control; (2) combination of tetracycline fibres with subgingival mechanical debridement results in significant improvement over debridement alone. Evidence from these studies has led to approval of this treatment modality by the US Food and Drug Administration and by the European Union Regulatory Bodies. A clinical usage study involving 2711 subjects treated by 68 clinicians in Europe and North America indicated that the magnitude of the observed clinical outcomes is clinically relevant and that adverse events were rarely observed. A variety of clinical investigations aimed at the optimal incorporation of tetracycline fibres in a treatment strategy provide guidance in case selection. Cost of therapy and concerns of unnecessary usage of antibiotics should be considered. It is nonetheless concluded that combination of tetracycline fibres with mechanical debridement represents a documented treatment alternative, the application of which may offer clinical benefits to many patients.

Serum antibodies reacting with subgingival species in refractory periodontitis subjects

The purpose of this investigation was to compare the levels of serum IgG antibody to 85 subgingival species in 32 refractory periodontitis, 56 successfully treated, and 33 periodontally healthy subjects. Refractory subjects showed mean full mouth attachment loss and/or >3 sites showing attachment loss >2.5 mm within 1 year after 2 treatment modalities, scaling and root planing and surgery plus systemically administered tetracycline. Successfully-treated subjects showed mean attachment level gain and no sites with attachment loss >2.5 mm, 1 year post-therapy. Periodontally healthy subjects exhibited no pocket or attachment level >3 mm, and no evidence of progressing attachment loss during 1 year of monitoring. Baseline serum was obtained from each subject and tested against 85 subgingival species, including reference strains and strains isolated from refractory subjects, using checkerboard immunoblotting. Significance of differences in levels of serum antibody among groups were sought using the Kruskal-Wallis test. Refractory subjects constituted a heterogeneous group based on their serum antibody response to subgingival species. Some individuals had antibody reactions to many subgingival species, while other subjects showed fewer or low numbers of responses. On average, refractory subjects exhibited higher numbers and levels of serum antibody reactions to a wide range of subgingival species than successfully treated or periodontally healthy subjects. Differences in serum antibody among clinical groups were more striking at higher threshold levels of antibody (>50 microg/ml and > 100 microg/ml). The data showed that a subject was 10.1 x more likely to be refractory if the subject exhibited antibody reactions with >9 subgingival species at >50 microg/ml (p<0.001, after adjusting for multiple comparisons). Serum antibody to a subset of the test species differed among the clinical groups. Porphyromonas gingivalis, Bacteroidesforsythus, and some strains isolated from refractory subjects (a novel Neisseria sp., Enterococcus faecalis, Prevotella loescheii and Prevotella oulora) elicited high serum antibody in the successfully treated and refractory subjects. High levels of serum antibody to a Microbacterium lacticum-like organism, Streptococcus oralis, Streptococcus constellatus, Actinobacillus actinonmycetemcomitans serotype c and Haemophilus aphrophilus significantly increased the likelihood of a subject being refractory to conventional periodontal therapy.

Cigarette smoking and periodontal diseases: etiology and management of disease

Cigarette smoking has long been suspected to be associated with a variety of oral conditions including periodontal diseases. Experimental evidence accumulated over the last 2 decades has indicated that cigarette smoking is probably a true risk factor for periodontitis. This environmental exposure has been associated with 2- to 3-fold increases in the odds of developing clinically detectable periodontitis. Smokers have both increased prevalence and more severe extent of periodontal disease, as well as higher prevalence of tooth loss and edentulism, compared to non-smokers. The greater severity of periodontal destruction may be partly accounted for by the reported increases in the rate of periodontal disease progression. The noxious effect of smoking has been shown to be dose dependent and to be particularly marked in younger individuals; in these subjects, up to 51% of the observed risk of periodontitis was associated with smoking. Much of the literature has also indicated that smokers affected with periodontitis respond less favorably to both non-surgical, surgical, and regenerative periodontal treatments. The success rate of dental implants has also been shown to be compromised in smokers. Furthermore, longterm studies have pointed out that smoking was associated with recurrence of periodontitis during periodontal maintenance; the effect appeared to be dose dependent, with heavy smokers (> 10 cigarettes/day) presenting with higher levels of disease progression. The indication that previous smokers have lower levels of risk for periodontitis compared to current smokers is considered to be the strongest available evidence that smoking cessation will result in improved periodontal health and that smoking cessation counseling should be an integral part of periodontal therapy and prevention. So far, however, no randomized controlled clinical trial establishing the effect of smoking cessation and/or reduction on the periodontal outcomes has been reported. Given the present state of uncertainty about the periodontal benefits, but in light of the established general health gains for the patient that could be derived from a smoking cessation program, practitioners are incorporating smoking cessation counseling as an integral part of periodontal therapy. Furthermore, smoking status represents a key parameter to assess the periodontal risk of an individual subject and therefore to make evidence-based clinical decisions.

Distribution of periodontal disease in a Swedish adult population 1973, 1983 and 1993

The aim of this study was to compare changes in periodontal status in a Swedish population over a period of 20 years. Cross-sectional studies were carried out in Jönköping County in 1973, 1983, and 1993. Individuals were randomly selected from the following age groups: 20, 30, 40, 50, 60, and 70 years. A total of 600 individuals were examined in 1973, 597 in 1983, and 584 in 1993. The number of dentate individuals was 537 in 1973, 550 in 1983, and 552 in 1993. Based on clinical data and full mouth intra-oral radiographs, all individuals were classified into 5 groups according to the severity of the periodontal disease experience. Individuals were classified as having a healthy periodontium (group 1), gingivitis without signs of alveolar bone loss (group 2), moderate alveolar bone loss not exceeding 1/3 of the normal alveolar bone height (group 3), severe alveolar bone loss ranging between 1/3 and 2/3 of the normal alveolar bone height (group 4), or alveolar bone loss exceeding 2/3 of the normal bone height and angular bony defects and/or furcation defects (group 5). During these 20 years, the number of individuals in groups 1 and 2 increased from 49% in 1973 to 60% in 1993. In addition, there was a decrease in the number of individuals in group 3, the group with moderate periodontal bone loss. Groups 4 and 5 comprised 13% of the population and showed no change in general between 1983 and 1993. The individuals comprising these groups in 1993, however, had more teeth than those who comprised these groups in 1983; on the average, the individuals in disease group 4 had 4 more teeth and those in disease group 5, 2 more teeth per subject. In 1973, these 2 groups were considerably smaller, probably because of wider indications for tooth extractions and fewer possibilities for periodontal care which meant that many of these individuals had become edentulous and were not placed in a group. Individuals in groups 3, 4, and 5 were subdivided according to the number of surfaces (%) with gingivitis and periodontal pockets (> or =4 mm). In 1993, 20%, 42%. and 67% of the individuals in groups 3, 4, and 5 respectively were classified as diseased and in need of periodontal therapy with >20% bleeding sites and >10% sites with periodontal pockets > or =4 mm. In conclusion, an increase in the number of individuals with no marginal bone loss and a decrease in the number of individuals with moderate alveolar bone loss can be seen. The prevalence of individuals in the severe periodontal disease groups (4, 5) was unchanged during the last 10 years; however, the number of teeth per subject increased.

Serum IgG2 level, Gm(23) allotype and FcgammaRIIa and FcgammaRIIIb receptors in refractory periodontal disease

The purpose of this investigation was to compare the levels of serum IgG2, the frequency of detection of Gm(23)-negative allotype and frequency of detection of FcgammaRIIa and FcgammaRIIIb receptor haplotypes in 32 refractory, 54 successfully treated and 27 periodontally healthy individuals. Refractory subjects showed mean full mouth attachment loss and/or >3 sites with attachment loss >2.5 mm within 1 year after both scaling and root planing, and surgery plus systemically administered tetracycline. Successfully treated subjects showed mean attachment level gain and no sites with attachment loss >2.5 mm 1 year post-therapy. Periodontally healthy subjects exhibited no pocket depth or attachment level >3 mm, and no evidence of progressing disease during 1 year of monitoring. Blood was obtained from each subject at baseline. Serum IgG2 and Gm(23) allotype were determined using radial immunodiffusion. DNA was extracted from whole blood and the FcgammaR genotypes determined using PCR and allele specific oligonucleotide probes. Significance of differences among clinical groups were sought using the Kruskal-Wallis or chi-square tests. Associations between 2 or more variables were tested using regression analysis. Refractory subjects exhibited higher mean attachment loss and pocket depth than successfully treated or periodontally healthy subjects. Smoking status did not differ significantly among groups. No significant differences in serum IgG2 levels and frequency of detection of Gm(23)-negative allotype were observed among the clinical groups. Serum IgG2 level was positively associated with the number of serum antibody responses to subgingival species (r=0.51, p<0.001). Subjects with the Gm(23)-negative allotype exhibited lower mean levels of serum IgG2 (3.06+/-0.3 versus 3.9+/-0.2, p<0.01) and mean number of serum antibodies to subgingival species (17.7+/-1.7 versus 23.3+/-1.4, p<0.05) than allotype positive individuals. No significant differences in FcgammaR haplotype distribution were observed among the 3 clinical groups. Associations of serum IgG2 level, Gm(23) allotype, FcgammaRIIa and FcgammaRIIIb receptor haplotypes and smoking status were weakly related or not related to clinical status. This lack of relationship may have been due to a reality of no relationship, or the inadvertent pooling of subjects where these factors were of primary importance with subjects in whom these factors played a less important role.

Therapy-resistant periodontitis. Psychosocial characteristics

This study investigated the perspective of a stress system disorder in the pathogenesis of therapy-resistant periodontitis. The goal was to find indications that the stress-behaviour-immune system model holds as an explanatory model for the understanding of periodontal disease. 2 patient-groups were compared: one group classified as responding well to periodontal treatment (responsive-group, R-group, n=11); the other group was classified as responding less well to treatment (non-responsive-group, NR-group, n=11). Somatic and psychological factors were described as obtained by interviews and psychological testings. These findings were related to clinical data documented during the treatment of the patients. An exact logistic multivariate regression analysis was performed on a model based on variables selected by bivariate analysis (variable versus group). The results indicated that the NR-group patients displayed indications of more psychosocial strain and a more passive-dependent personality. The R-group patients displayed a more rigid personality and possibly a less stressful psychosocial situation in the past. The report highlights the possible contribution of stress factors in the context of therapy resistant periodontal disease, and the results seem to be understandable within the context of a stress system disorder perspective.

Therapy-resistant periodontitis (I). Clinical and treatment characteristics

The aim of this study was to evaluate the clinical criteria for classification of 2 different patient groups. From retrospective comparisons of pocket probing depth (PPD) charts, we classified 22 patients as either non-responding or responding to periodontal treatment. The non-responding patient group, in comparison with the responding patient group, showed a profile over time of less PPD reduction in response to periodontal treatment. Information registered in each patient's file regarding clinical periodontal conditions, as well as treatment procedure characteristics, was gathered. Bivariate analyses were performed. 3 clinical variables (frequency of mean PPD > or = 6 mm during the treatment period; at final registration; and the mobility score at the final registration) indicated that 2 separate patient groups had been identified. Although the patient groups exhibited advanced periodontitis at the beginning of treatment, both groups at the end of treatment had lost very few (1-2) teeth, probably as a result of regular supportive treatment. The characteristics of the selected clinical criteria warrant the use of these 2 patient groups in further analysis of the relation of psychosocial stress and microbiological characteristics of therapy-resistant periodontitis.

Therapy-resistant periodontitis (II). Compliance and general and dental health experiences

In this exploratory case-control study, somatic and psychological factors are used for exploring whether the anamnestic information gives support to the hypothesis of a relationship between therapy-resistant periodontitis and stress factors. From retrospective comparisons of pocket probing depth charts, we classified 22 patients as either non-responding or responding to periodontal treatment. The non-responding patient group, in comparison with the responding patient group, showed a profile over time of less pocket probing depth (PPD) reduction in response to periodontal treatment. Information registered in each patient's file regarding periodontal registrations and dental status was gathered, and an interview was conducted aiming at collecting information on dental experiences and attitudes. Bivariate and logistic multivariate regression analyses were performed. The NR-group patients experienced significantly more unpleasant feelings towards dental procedures and a higher tendency to experience pain in connection with dental procedures. This group was found to start smoking at an older age than the R-group. One reason for this may be that smoking debut at an older age is more related to stress conditions than debut at a younger age. The report highlights the possible contribution of stress factors in periodontal disease.