A rationale for the management of periodontal diseases: effects of tetracycline on subgingival bacteria

Local delivery system of doxycycline hyclate based on ε-caprolactone copolymers for periodontitis treatment

The aim of the study was to evaluate kinetics of doxycycline hyclate release from polymeric bioresorbable implants and to examine suitability of this system for local treatment of periodontitis. Selected trimethylene carbonate/ϵ-caprolactone (TMC/CL) and glycolide/caprolactone (GL/CL) copolymers were synthesized and used as carriers in the form of small elastic rings with 5 wt% and 10 wt% doxycycline hyclate content, or in the form of flakes obtained through electro-spinning technique. The release of the drug under in vitro conditions has been tested. The study has shown that equimolar TMC/CL copolymer loaded with 10 wt% of doxycycline hyclate appears to be the most suitable copolymer for assumed system. The drug release proceeds mainly by diffusion of medium into the polymeric matrix and then the drug is washed out. Daily validation of doxycycline doses released by the system should ensure accurate course of the therapy.

Lessons learned and unlearned in periodontal microbiology

Periodontal diseases are initiated by bacterial species living in polymicrobial biofilms at or below the gingival margin and progress largely as a result of the inflammation elicited by specific subgingival species. In the past few decades, efforts to understand the periodontal microbiota have led to an exponential increase in information about biofilms associated with periodontal health and disease. In fact, the oral microbiota is one of the best-characterized microbiomes that colonize the human body. Despite this increased knowledge, one has to ask if our fundamental concepts of the etiology and pathogenesis of periodontal diseases have really changed. In this article we will review how our comprehension of the structure and function of the subgingival microbiota has evolved over the years in search of lessons learned and unlearned in periodontal microbiology. More specifically, this review focuses on: (i) how the data obtained through molecular techniques have impacted our knowledge of the etiology of periodontal infections; (ii) the potential role of viruses in the etiopathogenesis of periodontal diseases; (iii) how concepts of microbial ecology have expanded our understanding of host-microbe interactions that might lead to periodontal diseases; (iv) the role of inflammation in the pathogenesis of periodontal diseases; and (v) the impact of these evolving concepts on therapeutic and preventive strategies to periodontal infections. We will conclude by reviewing how novel systems-biology approaches promise to unravel new details of the pathogenesis of periodontal diseases and hopefully lead to a better understanding of their mechanisms.

Clinical and microbiological effects of different antimicrobials on generalized aggressive periodontitis

AIM

To evaluate and compare the effects of adjunctive metronidazole plus amoxicillin, doxycycline and metronidazole on clinical and microbiological parameters in patients with generalized aggressive periodontitis.

MATERIAL AND METHODS

Forty-three patients participated in this randomized clinical trial divided into four groups. Six weeks after scaling and root planning (SRP), groups 1-3 received adjunctive metronidazole, plus amoxicillin, doxycycline and metronidazole respectively, and group 4 acted as controls. Clinical recordings concerning probing depth, probing attachment level and bleeding on probing were performed at baseline, 6 weeks after SRP and 6 months from baseline. Subgingival samples were analysed using the 'checkerboard' DNA-DNA hybridization for Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Tannerella forsythia and Treponema denticola.

RESULTS

All treatments resulted in improvement of clinical parameters (ANOVA p > 0.05). Systemic administration of metronidazole plus amoxicillin or metronidazole resulted in statistically significant greater reduction of the proportion of sites > 6 mm than SRP (z-test, p < 0.05). These antimicrobials yielded a significant effect on levels of important periodontal pathogens for 6 months.

CONCLUSION

Adjunctive metronidazole plus amoxicillin or metronidazole alone (when A.actinomycetemcomitans is not involved) is effective in deep pockets of aggressive periodontitis patients.

Systemic antibiotics in periodontics

This position paper addresses the role of systemic antibiotics in the treatment of periodontal disease. Topical antibiotic therapy is not discussed here. The paper was prepared by the Research, Science and Therapy Committee of the American Academy of Periodontology. The document consists of three sections: 1) concept of antibiotic periodontal therapy; 2) efficacy of antibiotic periodontal therapy; and 3) practical aspects of antibiotic periodontal therapy. The conclusions drawn in this paper represent the position of the American Academy of Periodontology and are intended for the information of the dental profession.

Non-Surgical Periodontal Therapy With Adjunctive Topical Doxycycline: A Double-Masked, Randomized, Controlled Multicenter Study. II. Microbiological Results

BACKGROUND

Topical application of active substances offers an additional option in periodontal therapy. The aim of this study was to examine the influence of the administration of a novel, biodegradable 14% doxycycline gel on microbiological findings, in connection with scaling and root planing.

METHODS

One hundred ten patients in three centers (Frankfurt and Heidelberg, Germany; Nijmegen, The Netherlands) with moderate to advanced periodontitis were evaluated in this randomized, double-masked, split-mouth clinical trial. In each patient, three test teeth were randomly assigned to one of three treatment modalities: 1) scaling and root planing (SRP) alone; 2) SRP with subgingival placebo gel (VEH); or 3) SRP and 14% doxycycline gel (DOX). Subgingival plaque samples were analyzed at baseline and 3 and 6 months after therapy for Actinobacillus actinomycetemcomitans (A.a.), Tannerella forsythensis (T.f.), Porphyromonas gingivalis (P.g.), and Treponema denticola (T.d.) using a RNA probe. Samples from 10 patients were tested for resistance against doxycycline, amoxicillin/clavulanic acid, cefoxitin, clindamycin, and metronidazole using agar diffusion testing.

RESULTS

The largest decrease in pathogens was found after 3 months, with the most pronounced differences between DOX and SRP (P <0.05). At 6 months, pathogens were still reduced markedly in all groups. Treatment results were consolidated for VEH and DOX, with a slight deterioration for SRP (DOX versus SRP: P <0.001). Resistance was observed to amoxycillin/clavulanic acid, cefoxitin, clindamycin, and metronidazole (four isolates) but not to doxycycline.

CONCLUSION

The addition of subgingival instillation of a 14% doxycycline gel resulted in pronounced reduction of periodontal pathogens after 3 months and stabilizing results up to 6 months after therapy. Resistance to doxycycline was not induced.

A comparative evaluation of the clinical effects of systemic and local doxycycline in the treatment of chronic periodontitis

In this study, the clinical efficacies of systemic doxycycline (SD) and local doxycycline (LD) in the treatment of chronic periodontitis were compared. Forty-five patients were studied in 3 main groups with 5 treatments: SD alone, SD+scaling-root planing (SD+SRP), LD alone, LD+SRP and SRP alone. Antibiotic-treated patients were given doxycycline treatment alone in 1 quadrant of their upper jaws, and doxycycline+SRP was given in the contralateral quadrant. The areas included at least 4 teeth with > or = 5 mm pockets. Probing depth (PD), clinical attachment level, gingival index, sulcular bleeding index and plaque index values were recorded at baseline and the 7th week. The results were statistically analyzed. All of the clinical parameters were significantly reduced by all treatments (P < or = 0.05). The SD and LD treatments alone provided significant clinical healings. The significant differences among the groups were only in PD at the 7th week. The LD treatment provided significantly higher PD reduction than the SD treatment (P < or = 0.05). No significant difference was found between the SD+SRP and the LD+SRP treatments. There was no significant difference between SD+SRP and SRP alone treatment (P > 0.05). The SD group showed lower PD reduction than SRP group (P < or = 0.05), while no significant difference was found between LD and SRP treatments. The LD alone treatment seemed more effective than SD alone treatment on PD reduction, but no significant difference was found between them when combined with the SRP. LD may be more preferable than SD as an adjunct to mechanical treatment since LD seems more effective than SD on PD reduction and does not have the side effects of SD.

Topical and systemic antibiotics in the management of periodontal diseases

Both systemic and topical antibiotics are increasingly used in the management of periodontal infections. Whilst these drugs are used mostly on an empirical basis, some contend that rational use of antibiotics should be the norm due to their wide abuse and consequential global emergence of antibiotic resistance organisms. Here we review the rationale and principles of antimicrobial therapy, treatment goals, drug delivery routes and various antibiotics that are used in the management of periodontal diseases. The pros and cons of systemic and local antibiotic therapy are described together with practical guidelines for their delivery. The available data indicate, in general, that mechanical periodontal treatment alone is adequate to ameliorate or resolve the clinical condition in most cases, but adjunctive antimicrobial agents, delivered either locally or systemically, can enhance the effect of therapy in specific situations. This is particularly true for aggressive (early onset) periodontitis, in patients with generalised systemic disease that may affect host resistance and in case of poor response to conventional mechanical therapy. Locally delivered antibiotics together with mechanical debridement are indicated for non-responding sites of focal infection or in localised recurrent disease. After resolution of the periodontal infection, the patient should be placed on an individually tailored maintenance care programme. Optimal plaque control by the patient is of paramount importance for a favourable clinical and microbiological response to any form of periodontal therapy.

A systematic review on the effect of systemic antimicrobials as an adjunct to scaling and root planing in periodontitis patients

BACKGROUND

Scaling and root planing (SRP) are the bases of non-surgical therapy in the treatment of periodontitis. However, results from this therapy are often unpredictable and dependable from many different factors.

OBJECTIVES

The aim of this systematic review was to evaluate the effectiveness of the adjunctive use of systemic antimicrobials with scaling and root planing (SRP) vs. SRP alone in the treatment of chronic (CP) or aggressive periodontitis (AgP).

SEARCH STRATEGY

Use of computerized databases, namely MEDLINE, the Cochrane Oral Health Group Specialty Trials Register and EMBASE; reference lists from relevant articles were hand-searched; and a hand-search of selected journals until April 2001.

SELECTION CRITERIA

Studies were selected if they were designed as controlled clinical trials in which systemically healthy patients with either AgP or CP were treated with SRP plus systemic antimicrobials in comparison with SRP alone or with placebo, for a minimum of 6 months. Main outcome measures were clinical attachment level (CAL) change and probing pocket depth (PPD) change.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted independently information regarding quality and study characteristics, in duplicate. Kappa scores determined their agreement. Main results were collected and grouped by drug, disease and PPD category. For the quantitative data synthesis, the data was pooled (when mean differences and standard errors were available), and either a Fixed Effects or Random Effects meta-analysis was used for the analysis.

RESULTS

After an initial selection, 158 papers were identified by the manual and electronic searches; 25 papers were eligible for inclusion. Their quality assessment showed that randomization and allocation concealment methods were seldom reported and blindness was usually not defined clearly. In general, selected studies showed high variability and lack of relevant information for an adequate assessment. Overall, SRP plus systemic antimicrobial groups demonstrated better results in CAL and PPD change than SRP alone or with placebo groups. Only limited meta-analyses could be performed, due to the difficulties in pooling the studies and the lack of appropriate data. This analysis showed a statistically significant additional benefit for spiramycin (PPD change) and amoxicillin/metronidazole (CAL change) in deep pockets.

CONCLUSION

Systemic antimicrobials in conjunction with SRP, can offer an additional benefit over SRP alone in the treatment of periodontitis, in terms of CAL and PPD change, and reduced risk of additional CAL loss. However, differences in study methodology and lack of data precluded an adequate and complete pooling of data for a more comprehensive analyses. It was difficult to establish definitive conclusions, although patients with deep pockets, progressive or 'active' disease, or specific microbiological profile, can benefit more from this adjunctive therapy.

Topical metronidazole application compared with subgingival scaling. A clinical and microbiological study on recall patients

The aim of this study was to compare the topical application of a metronidazole 25% dental gel with subgingival scaling. 30 patients from the recall program participated in this open randomised study with split-mouth design. Pocket probing depths (PPD) and bleeding on probing (BOP) were measured before and 2, 12 and 24 weeks after the end of the treatment period. In addition, subgingival plaque samples were taken from all mesial sites and analysed with dark-field microscopy. All patients had at least 1 tooth in each quadrant with a PPD of 5 mm or more that should bleeding on probing, when entering the study. The treatment consisted of 2 applications of the dental gel in 2 randomly selected quadrants (on days 0 and 7) as well as simultaneous subgingival scaling of the remaining quadrants. Oral hygiene instruction was given on day 21. The average PPD and the average frequency of BOP were calculated for all sites with an initial PPD of 5 mm or more and continued at each examination, using the same sites. The statistical analyses showed that both treatments were effective in reducing PPD and BOP over the 6-month period. At the end of the follow-up period, the mean reduction in PPD was 1.3 mm after gel treatment and 1.5 mm after subgingival scaling. BOP was reduced by 35% and 42%, respectively. No significant differences between the 2 treatments were detected. Dark-field microscopy showed a shift toward a more healthy microflora for both treatment modalities; this persisted throughout the 6-month period. Application of a 25% metronidazole dental gel on recall patients seems to be as effective on the investigated clinical and microbiological parameters as subgingival scaling.

Evaluation of periodontal treatments using controlled-release tetracycline fibers: maintenance response

The purpose of this investigation was to examine periodontal disease recurrence from 3 to 12 months following various treatments with scaling and root planing and controlled-release tetracycline fibers. One-hundred-twenty-two (122) adult volunteers with at least one bleeding pocket > or = 5 mm in each of four quadrants were enrolled in this study. One or two such sites in each quadrant were selected as test sites. Quadrants were randomly assigned to receive one of four treatments: scaling and root planing (S); scaling and root planing plus tetracycline fiber for 10 days (SF); fiber therapy alone for 10 days (F); or fiber therapy alone for 20 days (FF). After treatment, no supportive care was provided during the 12-month study period. Probing depth (PD), attachment loss (AL), plaque, and bleeding on probing were measured at baseline, and at 1, 3, 6, 9, and 12 months after treatment. PD and AL measures were taken at three locations within each site and averaged for each site. Disease recurrence was defined as > or = 1 mm mean attachment loss at a site during the 3- to 12-month period. One-hundred-sixteen (116) subjects completed the study. Sites treated with SF experienced significantly (P < 0.05) less disease recurrence (4%) than S, F, or FF (9%, 10%, and 12%, respectively). Results of this study suggest that, compared to S, F, or FF, scaling and root planing in conjunction with tetracycline fiber therapy for 10 days can significantly reduce disease recurrence 3 to 12 months following treatment in the absence of supportive care.

Pharmacological control of periodontal disease. II. Antimicrobial agents

Antimicrobial agents are of value in the management of certain types of periodontal disease, notably early onset, juvenile and refractory periodontitis. The diagnosis of these conditions is often made on clinical grounds but microbial sampling of the pocket flora is of value in determining the type of antimicrobial therapy. Routine systemic use of these drugs in the management of chronic adult periodontitis is contraindicated, and is no substitute for root surface debridement and thorough supragingival plaque control. Tetracyclines and metronidazole are the agents most frequently used in the management of periodontal disease. Both drugs can be given systemically or applied topically into the periodontal pocket. The latter route is preferred since the dose is reduced considerably, but the local tissue concentration is increased. The efficacy of local drug delivery is dependent upon the release kinetics of the drug from the delivery vehicle. Although local application can be time consuming, it reduces the risk of adverse reactions and drug interactions. The tetracyclines have the additional advantage of inhibiting collagenases. This property may facilitate repair and new attachment formation. Systemic metronidazole appears to be useful as an adjunct to conventional periodontal therapy. The combination of metronidazole 250 mg and amoxycillin 375 mg has been shown to be effective in the treatment of refractory periodontitis, including cases which are resistant to tetracycline. Clindamycin has also been used in the management of refractory periodontitis, but the unwanted effects of this drug must limit its systemic use for this purpose.

Tetracyclines in the management of periodontal diseases. A review

Periodontal diseases essentially comprise a group of oral infections whose primary aetiological factor is dental plaque. Removal of the cause (and its effects) is the primary aim of both non-surgical and surgical treatment regimens, although the infective nature of the diseases has led to the widespread use of antimicrobials as an adjunct to mechanical debridement. The tetracyclines are primarily bacteriostatic agents that are effective against many Gram-negative species including putative periodontopathogens such as Actinobacillus actinomycetemcomitans (A.a.). The proven efficacy of this group of drugs in the management of periodontal diseases may be related not only to their antibacterial actions, but to a number of additional properties that have been recently identified. These include collagenase inhibition, anti-inflammatory actions, inhibition of bone resorption and their ability to promote the attachment of fibroblasts to root surfaces. Consequently, tetracyclines have also been used as an adjunct to bone grafting in periodontal defects, and as agents for 'conditioning' root surfaces to enhance the regeneration of periodontal tissues. When tetracyclines are taken orally, consideration must be given both to the potential unwanted effects and to interactions with other drugs that are taken concurrently. Such problems are minimised however, when the drugs are incorporated into controlled, slow-release formulations which are currently being researched and marketed for intra-oral use.

Quality assessment and meta-analysis of systemic tetracycline use in chronic adult periodontitis

The use of systemic tetracycline in the treatment of periodontal disease has been controversial. To investigate this controversy, we performed a quality assessment and attempted to perform a meta-analysis of 13 published studies. We evaluated the quality of the study protocol and data analysis and presentation for each study. We were unable to combine data from the majority of studies due to heterogeneity of the outcomes evaluated and limitations in data reported in the individual studies. Therefore, only 2 studies were included in the quantitative meta-analysis. On a scale of 0-1, the mean score for this group of studies was 0.27 (+/- 0.19) for study protocol and 0.31 (+/- 0.11) for data analysis and presentation. Mean reduction in probing depth for the group treated with tetracycline plus scaling was 2.45 mm; for the group which received only scaling, 2.02 mm; for the group that received only tetracycline, 1.98 mm; and for the control group, 0.65 mm. We conclude that analysis of data from the published literature does not demonstrate that the use of systemic tetracycline is more beneficial than conventional treatment in the management of adult periodontal disease. More information is needed in order to perform an extensive meta-analysis of this subject.

Antibiotics in periodontal therapy: advantages and disadvantages

Antibiotic treatment of periodontitis aims at eradicating or controlling specific pathogens. Prime candidates for antibiotic therapy are patients with recently diagnosed active periodontitis or a history of recurrent disease who fail to stabilize following mechanical/surgical therapy. Since a variety of microbes with differing antimicrobial susceptibility profiles may cause periodontitis, selection of antimicrobial agents should be based on proper microbial diagnosis and sensitivity testing, as well as consideration of the patient's medical status. The risk of treating chemotherapeutically solely on the basis of clinical features, radiographic findings or a limited microbiological analysis, is failure to control the pathogens or overgrowth of new pathogens. A review of published papers reveals that appropriate systemic antibiotic therapy may enhance healing in patients with recent or high risk of periodontal breakdown. Systemic antibiotic therapy seems more predictable than topical administration in eradicating periodontal pathogens from deep periodontal pockets. Several promising antimicrobial agents for periodontitis treatment need testing in placebo-controlled, double-blind, randomized clinical trials.

Rationale for the use of antimicrobial agents in periodontal disease

The traditional approach to treating dental decay and periodontal disease has often focused on caries, neglecting periodontal infection. The past 15 years have seen significant advances in the treatment of periodontal disease with antimicrobial therapy, both with and without more traditional debridement or surgery. This article presents an overview of the use of antimicrobials, including an examination of treatment philosophies and the diagnosis of periodontal infection.

Microbiological and clinical effects of chlorhexidine digluconate and hydrogen peroxide mouthrinses on developing plaque and gingivitis

While the ability of chlorhexidine (CHX) to prevent plaque formation and inhibit the development of gingivitis has been well documented in the literature, the therapeutic value of hydrogen peroxide (H2O2) in preventing gingivitis is in dispute. The purpose of this study was to compare the clinical and microbiological effects of an established therapeutic agent, such as chlorhexidine with that of H2O2 in the experimental gingivitis model. Following a period of stringent oral hygiene, 32 subjects were allocated to 1 of 3 treatment groups which were balanced on the basis of their pre-experimental gingivitis scores. The subjects then refrained from any oral hygiene for 21 days. During this period, they rinsed twice a day with either a placebo, 0.12% CHX, or a 1% H2O2 mouthrinse. After 21 days, supragingival and marginal plaque was collected from each subject and assayed for total cultivable microbiota, total facultative anaerobes, facultative Streptococci, Actinomyces, Fusobacterium, Veillonella and Capnocytophaga. At the end of the experimental period, the group rinsing with 0.12% CHX showed 95% reduction in gingivitis incidence, 100% reduction in bleeding sites, and 80% reduction in plaque scores compared to the group rinsing with placebo. Conversely, the group using 1% H2O2 showed a marginal reduction in gingivitis incidence of 15% and a 28% reduction in bleeding sites compared to the placebo group, but no significant reduction in plaque scores. The microbiological results showed that 0.12% CHX was an excellent broad-spectrum antimicrobial agent which significantly reduced the number of both facultative and obligate anaerobes in plaque.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative longitudinal study of 2 methods of scheduling maintenance visits; 2-year data

This report compares the clinical and microbiological status of 2 groups of subjects with treated periodontis on different maintenance schedules. 43 control (C) subjects were given prophylaxes every 3 months. 40 test (T) subjects were given this service on a flexible schedule according to the proportions of spirochetes and/or motile rods in fresh smears of subgingival scrapings. Both groups were examined every 6 months clinically and microbiologically. This report presents base line, 1- and 2-year data. Generally, mean values for both groups did not differ significantly from one another. Both groups exhibited comparable increases in GI and PLI scores during the first 2 years of this study. No change in probing depth was noted between base line and the 2-year examination. However, a slight increase in attachment level, as determined by probing, was noted in both groups. Both groups also exhibited similar proportions of bacterial morphotypes at base line and subsequent examinations. Disease recurrence, defined as an increase in probing depth of 3 mm or more from base line on any tooth surface during the 2-year period, tended to be more prevalent in the C than in the T group (15/43 C and 9/40 T subjects). However, the proportional difference between the groups was not statistically significant. Subjects with disease recurrence in the T group had greater proportions of spirochetes at base line than subjects in the same group without disease recurrence (20.2% versus 9.8%, p less than 0.01). This difference in proportions persisted if both groups were examined jointly, but was only of borderline significance (16.0% versus 10.5%, p = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Antimicrobial irrigation of deep pockets to supplement non-surgical periodontal therapy. II. Daily irrigation

106 sites with probing pocket depths 7 mm or greater from 14 patients were treated with plaque control instruction and 1 episode of root planing. Sites in each patient were either irrigated with 2% chlorhexidine or left as non-irrigated controls. Irrigation immediately followed root planing and was repeated daily, by the patient, for 24 weeks. Clinical measurements were made at 12 and 24 weeks, as were gingival washings for determining the number and % of spirochetes. Results at 24 weeks demonstrated that bleeding scores decreased from 91% to 9%; the % of spirochetes dropped from approximately 9% to less than 1%; probing pocket depths decreased from 7.5 to 4.5 mm, and probing attachment levels gained 1.1 to 1.4 mm. The chlorhexidine irrigated experimental group and the non-irrigated control group did not differ significantly in any of the studied parameters. Thus, daily patient-administered chlorhexidine irrigation of deep pockets did not augment the effects of non-surgical periodontal therapy.

The Keyes technique and self-inflicted injuries. Three case reports

Three cases of self-inflicted gingival injuries resulting from the improper use of the Keyes technique are presented. The profession must assume responsibility for studies to determine the safety of the methods of application of the hydrogen peroxide, salt and baking soda mixtures and disseminate this information for the public interest.

Antimicrobial irrigation of deep pockets to supplement oral hygiene instruction and root debridement. I. Bi-weekly irrigation

64 sites with probing pocket depth greater than or equal to 6 mm from 11 patients were treated with plaque control instruction and one episode of root planning. Subsequently, selected sites in each patient were irrigated with either chlorhexidine, tetracycline, saline or served as non-irrigated control sites. Irrigation immediately followed instrumentation, and was repeated every 2 weeks for 24 weeks. Healing was monitored at 8, 16, and 24 weeks clinically and at 7, 15, and 23 weeks with subgingival washings for determination of % as well as total number of spirochetes. The following changes were apparent from comparing pooled site means at 24 weeks with pretreatment data: (1) bleeding sites decreased from 62 of 64 sites initially to 22 of 64 at 24 weeks; (2) spirochetes decreased from 34% to 2%; (3) probing pocket depths decreased from 7.6 to 4.7 mm; (4) probing attachment levels showed a gain of 1.2 mm. The improvement of the chlorhexidine and tetracycline irrigated sites was similar to that of the saline irrigated and non-irrigated control sites. Thus, biweekly chlorhexidine, tetracycline or saline irrigation of deep pockets did not appear to augment the effects of non-surgical periodontal therapy.

Orthodontic therapy in patients with juvenile periodontitis: clinical and microbiologic effects

The correction of malocclusions in juvenile periodontitis (JP) patients completing periodontal therapy is a problem of increasing clinical concern to orthodontists, since many teeth with severe alveolar bone loss in these patients can now be successfully treated without extraction. In this report, fixed edgewise orthodontic therapy was carried out after the completion of periodontal therapy on four JP patients. The orthodontic therapy included extensive intrusion of teeth severely affected by JP. Phase-contrast microscopic analysis of subgingival plaque from orthodontically treated teeth was used to monitor longitudinally the effects of fixed orthodontic bands on the subgingival flora and also to monitor the efficacy of topical and systemic antimicrobial therapy aimed at suppression of suspected periodontopathic bacteria. Orthodontic movement was completed on most periodontally compromised teeth without significant evidence of additional deterioration in periodontal status. However, within the first 6 months of orthodontic band placement, all patients had significant increases in the number of spirochetes and motile rods in their subgingival flora. Three of the patients also developed high levels of crevicular polymorphonuclear leukocytes around orthodontically treated teeth, indicating significant subgingival inflammation. Intensive antimicrobial measures, including topical inorganic salt applications and systemic tetracycline, were helpful in limiting clinical inflammation and subgingival colonization by periodontopathogens during orthodontic therapy. The results demonstrate that successful orthodontic repositioning can be carried out in treated JP patients. In addition, bacteriologic monitoring and chemotherapeutic suppression of periodontal pathogens may be valuable in the prevention of further destructive periodontal disease activity in periodontitis patients undergoing orthodontic therapy.

The effect of Keyes' method of oral hygiene on the subgingival microflora compared to the effect of scaling and/or surgery

The present study was conducted on 18 individuals to determine if Keyes' method of oral hygiene would present an alternative to traditional periodontal therapy in terms of establishing a subgingival microflora compatible with periodontal health. Oral hygiene, gingival conditions and subgingival microbial proportions assessed by dark field microscopy were measured at baseline, then once every 2 weeks for the remainder of this 8-week study. In addition, probing depths and bleeding on probing were evaluated. Group I (9 patients) was treated non-surgically, while Group II (9 patients) had received surgical therapy within the last 4 years. Both groups received routine scaling and root planing (Sc/RP) on one arch at time 0, and both were instructed to use Keyes' method of oral hygiene on one side of the mouth while the other side served as a control. This yielded a split-plot experimental design which permitted examination of the effects of Keyes' method of oral hygiene, Sc/RP and surgery. The results revealed no statistically significant differences between Keyes' method of oral hygiene and conventional oral hygiene in patients treated with a single session of Sc/RP. When scaling was not employed, Keyes' method was more effective than conventional oral hygiene. Surgical status was found to be the most significant factor in reducing clinical indicator values and establishing control of the subgingival microflora. In summary, oral hygiene alone had only minimal effects on subgingival microbial proportions. The primary antimicrobial effect observed, as evidenced by shifts in subgingival morphotype proportions, was produced by the Sc/RP procedure. This effect was enhanced by improved access (surgical status).

3-year longitudinal study of the periodontal status of an adult population with gingivitis

69 adults ranging in age from 20 to 73 (mean age: 37) were randomly assigned to a control (C) and a test (T) group. Of these, 61 completed the 3-year longitudinal study. All subjects had varying degrees of gingivitis at the start, but no overt periodontitis. Following a base line examination for P1I, GI, probing depth (PD) and recession, a differential darkfield microscopic (DDFM) count of subgingival bacterial morphotypes was carried out on a pooled sample originating from one tooth surface in each sextant with the greatest probing depth. Examinations were repeated every 6 months for 3 years. The C group received regular prophylaxes every 6 months. The T subjects received prophylaxes according to a previously described schedule, and on the basis of the DDFM test outcome. Recall intervals at the end of the study for the T group ranged from 1 to 24 months (mean: 15.7 months). Of 30 subjects in the T group at the end of the study, one half had not had their teeth cleaned for periods of 18 to 36 months without any detectable deterioration in their periodontal status by comparison with the other T subjects or the patients in the C group. Both C and T subjects exhibited increased mean P1I and GI scores as compared to base line during the first half of the study. However, mean PD measurements remained unchanged. Increases in PD from base line of 3 mm or more were observed only in approximately 1 out of a 1000 individual tooth surface comparisons, a frequency comparable to that expected to occur by chance alone. This observation indicates that in this population, little if any pocket formation occurred during the study period. GI score increases of 2 units or more occurred in relatively few subjects. 2 of 31 C patients accounted for 42% of the affected dental units, while 5 out of 30 T subjects accounted for 40.8% of the affected dental units in that group. These observations suggest that despite the relatively high prevalence and incidence of gingivitis, the subjects were relatively resistant to periodontitis. Neither preventive schedule was effective in eliminating gingivitis. The lack of significant destructive disease in this population prevented any meaningful comparison of the relative effectiveness of the two preventive maintenance regimens in preventing recurrences of periodontitis.

Inhibition of bacterial growth by tetracycline-impregnated enamel and dentin

Tetracyclines can react with enamel and dentin to form relatively insoluble fluorescent compounds. The purpose of this study was to evaluate the possible antimicrobial effect of these reaction products on various microorganisms associated with human dental plaque and periodontal disease. Slabs of native dentin and enamel as well as demineralized dentin were immersed in aqueous solutions of tetracycline HCl, oxytetracycline HCl and doxycycline HCl for periods of 1 h or 24 h. Unimpregnated enamel and dentin slabs sterilized by gamma irradiation and specimens impregnated with phenoxymethylpenicillin calcium were used as controls. Test and control specimens were placed on agar plates seeded with B. cereus, C. ochraceus, S. sanguis, F. nucleatum, B. melaninogenicus or A. viscosus and were subsequently incubated aerobically or anaerobically at 37 degrees C. With the exception of enamel impregnated for 1 h in a 0.01 mg/ml tetracycline solution, all test specimens caused growth inhibition zones, varying in size according to concentration of the drug, immersion period and bacterial species. The results indicate that tetracyclines react with enamel and dentin to form slightly soluble compounds with a pronounced antibacterial effect. In comparison, the antimicrobial effect of dentin treated with penicillin was small.