Intrapocket chemotherapy in adult periodontitis using a new controlled-release insert containing ofloxacin (PT-01)

Recommendations for treating stage I-III periodontitis in the Taiwanese population: A consensus report from the Taiwan Academy of Periodontology

BACKGROUND/PURPOSE

Based on the fundamental of the S3-level clinical practice guideline (CPG) for treating stage I-III periodontitis developed by the European Federation of Periodontology (EFP), this consensus report aimed to develop treatment recommendations for treating periodontitis in the Taiwanese population.

METHODS

The report was constructed by experts from the Taiwan Academy of Periodontology. The following topics were reviewed: (a) the prevalence of periodontitis in Asia and current status of treatment in Taiwan; (b) specific anatomical considerations for treating periodontitis in Asians; (d) educational and preventive interventions and supragingival plaque control; (d) subgingival instrumentation and adjunctive treatment; (e) surgical periodontal therapy; and (f) maintenance and supportive periodontal care. Recommendations were made according to the evidences from the EFP CPG, the published literature and clinical studies in Asians, and the expert opinions.

RESULTS

The treatment recommendations for the Taiwanese population were generally in parallel with the EFP CPG, and extra cautions during treatment and maintenance phases were advised due to the anatomical variations, such as shorter root trunk, higher prevalence of supernumerary distolingual root and lingual bony concavity in mandibular posteriors, and thinner anterior labial plate, of the Asian population.

CONCLUSION

The EFP CPG could be adopted for treating periodontitis and maintaining periodontal health of the Taiwanese population, and anatomical variations should be cautious when the treatment is delivered.

Sustained-release delivery of antimicrobial drugs for the treatment of periodontal diseases: Fantasy or already reality?

Periodontal diseases are prevalent in humans. Conventional means of combating these diseases involve basic oral hygiene, mostly toothbrushing, use of mouthwashes, and flossing. Supplementary means of treatment, either clinical or pharmaceutical, are often necessary. The use of sustained-release delivery systems, applied locally to the periodontal pocket, seems to be one feasible approach: local sustained-release delivery of antibacterial agents to treat periodontal diseases is conceivable. The use of local (intrapocket) sustained-release delivery systems has numerous clinical, pharmacologic, and toxicologic advantages over conventional treatments for periodontal diseases. Sustained-release technology has been proven to be effective over the last few decades. Films, gels, and fibers are the three main classical intrapocket pharmaceutical delivery systems. Research today is more focused on improving drug delivery, and less on introducing new drugs. New approaches, eg, those making use of nanotechnology, are emerging for local drug-delivery systems. The local sustained-release delivery system concept is innovative and a few products are already commercially available.

Antibacterial activity of moxifloxacin on bacteria associated with periodontitis within a biofilm

The activity of moxifloxacin was compared with ofloxacin and doxycycline against bacteria associated with periodontitis within a biofilm (single strain and mixed population) in vitro. MICs and minimal bactericidal concentrations (MBCs) of moxifloxacin, ofloxacin and doxycyline were determined against single strains and mixed populations in a planktonic state. Single-species biofilms of two Porphyromonas gingivalis and two Aggregatibacter actinomycetemcomitans strains and a multispecies biofilm consisting of 12 species were formed for 3 days. The minimal biofilm eradication concentrations (MBECs) were determined after exposing the biofilms to the antibacterials (0.002-512 µg ml(-1)) for 18 h, addition of nutrient broth for 3 days and subsequent subcultivation. Photographs were taken using confocal laser-scanning microscopy and scanning electron microscopy. The MICs and MBCs did not differ between ofloxacin and moxifloxacin against A. actinomycetemcomitans, whilst moxifloxacin was more active than the other tested antibacterials against anaerobes and the mixed population. The single-species biofilms were eradicated by moderate concentrations of the antibacterials, and the lowest MBECs were always found for moxifloxacin (2-8 µg ml(-1)). MBECs against the multispecies biofilms were 128, >512 and >512 µg ml(-1) for moxifloxacin, ofloxacin and doxycycline, respectively. In summary, moxifloxacin in a topical formulation may have potential as an adjunct to mechanical removal of the biofilms.

Treatment modalities and evaluation models for periodontitis

Periodontitis is the most common localized dental inflammatory disease related with several pathological conditions like inflammation of gums (gingivitis), degeneration of periodontal ligament, dental cementum and alveolar bone loss. In this perspective, the various preventive and treatment modalities, including oral hygiene, gingival irrigations, mechanical instrumentation, full mouth disinfection, host modulation and antimicrobial therapy, which are used either as adjunctive treatments or as stand-alone therapies in the non-surgical management of periodontal infections, have been discussed. Intra-pocket, sustained release systems have emerged as a novel paradigm for the future research. In this article, special consideration is given to different locally delivered anti-microbial and anti inflammatory medications which are either commercially available or are currently under consideration for Food and Drug Administration (FDA) approval. The various in vitro dissolution models and microbiological strain investigated to impersonate the infected and inflamed periodontal cavity and to predict the in vivo performance of treatment modalities have also been thrashed out. Animal models that have been employed to explore the pathology at the different stages of periodontitis and to evaluate its treatment modalities are enlightened in this proposed review.

Controlled and targeted drug delivery strategies towards intraperiodontal pocket diseases

Advances in the understanding of the aetiology, epidemiology, pathogenesis and microbiology of periodontal pocket flora have revolutionized the strategies for the management of intraperiodontal pocket diseases. Intra-pocket, sustained release, drug delivery devices have been shown to be clinically effective in the treatment of periodontal infections. Several degradable and non-degradable devices are under investigation for the delivery of antimicrobial agents into the periodontal pocket including non-biodegradable fibres, films (biodegradable and non-biodegradable), bio-absorbable dental materials, biodegradable gels/ointments, injectables and microcapsules. With the realization that pocket bacteria accumulate as biofilms, studies are now being directed towards eliminating/killing biofilm concentrations rather than their planktonic (fluid phase) counterparts. Intraperiodontal pocket drug delivery has emerged as a novel paradigm for the future research. Similarly, bioadhesive delivery systems are explored that could significantly improve oral therapeutics for periodontal disease and mucosal lesions. A strategy is to target a wide range of molecular mediators of tissue destruction and hence arrest periodontal disease progression. Research into regenerating periodontal structures lost as a result of disease has also shown substantial progress in the last 25 years.

In vitro assessment of the antimicrobial activity of a local sustained release device containing amine fluoride for the treatment of oral infectious diseases

Dental caries and periodontal diseases are chronic infectious diseases caused by oral bacteria. Local sustained release delivery systems extend the time in which the drug is present in the oral cavity, thus enhancing its therapeutic potential while reducing its side effects. Amine-fluorides (AmF) are known anticaries agents and have recently been found to have an antibacterial effect against periodontal pathogens and caries-associated bacteria. The purpose of this in vitro study was to assess the antimicrobial activity of a local sustained release device (LSRD) containing AmF on Streptococcus sobrinus 6715. LSRD was prepared from an ethylcellulose matrix containing AmF. Release kinetics of AmF from the LSRD was measured simultaneously with its antimicrobial activity. The organic amine and the fluoride were released in different kinetics profiles: The fluoride was released faster than the organic amine. The antimicrobial activity of AmF was measured on planktonic bacteria in solution and on bacteria as part of experimental dental plaque. During a 10-day period, the concentration of the released AmF was above its MIC and no bacterial growth was observed. Bacterial counts in the dental plaque were reduced by 1 to 2 log units. Hence, the LSRD containing AmF has the potential to serve as a medicament in prevention and treatment of dental caries and periodontal diseases.

Multi-center comparative evaluation of subgingivally delivered sanguinarine and doxycycline in the treatment of periodontitis. I. Study design, procedures, and management

The design and conduct of a 9-month multi-center clinical trial to evaluate the safety and efficacy of subgingivally delivered 5% sanguinarium chloride (SC) and 10% doxycycline hyclate (DH) from a biodegradable drug delivery system in the treatment of adult periodontitis is described. The 3-group randomized study of 180 adults with moderate to severe periodontitis was a modified double-blind parallel design. One group received DH, one group received SC, and the other group received the vehicle control (VC). Patients selected had two quadrants with a minimum of four periodontal pockets > or = 5 mm in depth with two sites > or = 7 mm. All qualifying sites exhibited bleeding on gentle probing. Qualifying sites were treated at baseline and again at 4 months. Clinical response was assessed by measuring attachment level, probing depth, and bleeding on probing at monthly examinations at qualifying sites and the entire dentition. The plaque index was measured monthly to verify oral hygiene status. The parallel design afforded the opportunity to distinguish between treatment effectiveness of SC, DH, and VC independent of possible crossover effects. Also the effectiveness of oral hygiene in untreated sites of the mouth could be evaluated. Finally, treatment effects in moderate (5 to 6 mm) and deep (> or = 7 mm) pockets in both treated and untreated sites could be compared. The design was capable of simulating a periodontal practice maintenance program and assessing the response according to maintenance and treatment history. Study management procedures that emphasized center examiner and therapist training and adherence to protocol and procedures to reduce variability are described.

Periodontal pocket treatment in beagle dogs using subgingival doxycycline from a biodegradable system. I. Initial clinical responses

The present study evaluated the clinical response of periodontal pockets in beagle dogs after treatment with a biodegradable delivery system containing 10% doxycycline hyclate (ABDS-D). Eight adult, female beagle dogs had generalized, severe periodontitis with plaque and calculus-laden pockets. In each animal, 3 teeth with multiple pocket sites > or = 4 mm (mean depth = 6.0 mm) associated with attachment loss (mean = 5.4 mm) and which bled on probing (mean score = 2.5) were treated with a single application of either ABDS-D (experimental group) or the delivery system alone without the doxycycline (control group). Residual polymer was removed at day 7. Bioassay of doxycycline in gingival crevicular fluid associated with presence of ABDS-D gave mean levels of bioactivity of approximately 250 micrograms/ml. Levels of bioactive doxycycline were detected for approximately 7 days after ABDS-D removal. Periodontal maintenance consisted of thrice-weekly toothbrushing the treated sites. Clinical responses were evaluated at 2 weeks, and at bi-weekly intervals thereafter for 4 months. Analyses of the data from the control group showed that there was only slight clinical improvement. In contrast, in the experimental group, bleeding on probing and probing depths were significantly reduced from baseline at all post-treatment time points. At 1 month, mean probing depth reduction was 2.4 mm and this was maintained at 4 months (mean reduction = 2.5 mm). These probing depth reductions occurred primarily through gain of clinical attachment which was 2.0 mm at 4 months. Bleeding had been virtually eliminated (mean = 0.2). It was concluded that, for the beagle dogs with severely infected periodontal pockets in this study, treatment with subgingival doxycycline using the delivery system resulted in substantial improvement in periodontal health.

Microbial flora in the acute phase of periodontitis and the effect of local administration of minocycline

Periodontitis, similar to other infectious diseases, is known to progress as chronic inflammation with recurrent acute phases. The purpose of this study was to clarify the microbiological composition of the acute phase and to compare the bacterial flora with that of comparable chronic periodontal pockets. We also evaluated the effect of application of minocycline gel locally on the change in the microflora in the acute pockets. Microbial flora from the subgingival pockets of 28 patients in the acute phase of periodontitis and of 12 patients in a comparable chronic phase as the control were investigated by various bacterial culture methods including TS blood agar and TSBV plates. Minocycline gel was applied to the acute periodontal pockets. Changes in the microbiological proportion and clinical parameters at one week after baseline examination were followed by dark-field analysis, culture method, and indirect immunofluorescence technique. Characteristic features of bacterial proportions in the acute site were observed as an increase in Bacteroides forsythus. The number of Porphyromonas gingivalis and black pigmented anaerobic rods also increased. Application of minocycline gel in the acute pocket without any debridement produced improvement in clinical symptoms at one week. Black-pigmented anaerobic rods, P. gingivalis, and B. forsythus decreased significantly at one week after the application. Results indicate that periodontopathic bacteria including B. forsythus and P. gingivalis were predominant in the acute phase of periodontitis and a locally delivered antibiotic may be effective as an alternative modality of treating the acute inflammation.

Current status of systemic antibiotic usage in destructive periodontal disease

The recognition that periodontal diseases are primarily caused by specific microorganisms has led researchers to explore the possibility that antibiotics may enhance the effect of mechanical debridement procedures such as scaling and surgery. For some selected periodontal diseases, this has proven to be true. This paper will review systemically-administered antibiotics and the clinical studies and case reports supporting their use. In periodontal therapy, the tetracyclines are the most commonly-used antibiotics in the United States. Tetracycline hydrochloride, minocycline, and doxycycline have been shown to inhibit in vitro most putative periodontal pathogens. Several studies support the use of tetracyclines in the treatment of localized juvenile periodontitis. Penicillins such as amoxicillin are effective in vitro against most periodontal pathogens but have limited efficacy due to the presence of beta-lactamases in gingival fluid. Amoxicillin/clavulanate potassium (Au) has proven effective in treating adult refractory periodontitis characterized by a Gram-positive flora. Metronidazole is an effective adjunct in adult periodontitis associated with high numbers of "black-pigmented Bacteroides" ad spirochetes. A combination of metronidazole and amoxicillin produces a synergistic effect against A. actinomycetemcomitans and has been shown to be effective at eliminating this organism. Clindamycin is an effective adjunct in the treatment of adult refractory periodontitis associated with a predominantly Gram-negative flora. The use of macrolides, quinolones, and combinations of antibiotics is discussed. Clinical studies do not support the use of systemically-administered antibiotics in routine adult periodontitis. Clinical studies do, however, support the use of antibiotics in the treatment of specific periodontal diseases.

Controlled-release local delivery antimicrobials in periodontics: prospects for the future

New knowledge about the microbial etiology of periodontal diseases emerged in the 1970s and 1980s and led to widespread interest in the use of antimicrobial agents to treat periodontitis. The controlled-release delivery of antimicrobials directly into the periodontal pocket has received great interest and appears to hold some promise in periodontal therapy. Some techniques for applying antimicrobials subgingivally, such as subgingival irrigation, involve local delivery but not controlled-release. Controlled-release local delivery systems, in which the antimicrobial is available at therapeutic levels for several days, have been evaluated in several forms and using different antimicrobials. Although most studies with such systems have focused on drug delivery kinetics and "proof of principle" evaluations, some controlled clinical trials have recently been reported. The most widely tested system, monolithic tetracycline-containing fibers, has shown significant clinical benefit when used alone as compared to no subgingival therapy. Similarly, controlled trials involving chlorhexidine strips used subgingivally every 3 months in place of routine supportive periodontal therapy have shown significant clinical benefit for up to 2 years. Although these data are now emerging, many questions concerning the optimal use and role of this therapy in clinical practice remain. This review attempts to summarize and interpret current data and to outline key remaining questions that must be addressed as this technology is transferred into clinical practice.

Recent advances in periodontal diagnosis and treatment: exploring new treatment alternatives

A better understanding of the etiology and pathogenesis of periodontal diseases provides clinicians and researchers with a number of new diagnostic techniques and treatment alternatives. These new developments may also offer the clinician additional information for treatment planning.