Clinical and microbiological effects of minocycline-loaded microcapsules in adult periodontitis

Efficacy of Local Minocycline Agents in Treating Peri-Implantitis: An Experimental In Vivo Study in Beagle Dogs

BACKGROUND

Local delivery agents (LDA) have the advantage of delivering the antibiotics at high concentrations to the targeted sites. However, the constant flow of gingival crevicular fluids and saliva may restrict their efficacy. Therefore, the drug sustainability and pharmacodynamic properties of any proposed LDA should be evaluated.

METHODS

Four dental implants were placed unilaterally in the edentulous mandible of six beagle dogs. Peri-implantitis were experimentally induced using silk-ligatures. Each implant was randomly allocated to receive one of the following four treatments: (i) MC (Chitosan-alginate (CA) minocycline), (ii) MP (CA-without minocycline), (iii) PG (Polyacrylate-glycerin minocycline), and (iv) Control (mechanical debridement only). Mechanical therapies and LDAs were administered into the gingival sulcus two times at a 4-week interval. Drug sustainability as well as clinical, radiographical, and immunohistochemical (IHC) analyses were conducted to evaluate the efficacies of treatments.

RESULTS

Reduced mean probing depth was observed in all of the test groups after the second delivery. A minimal marginal bone level change was observed during the treatment period (MP (-0.06 ± 0.53 mm) to PG (-0.25 ± 0.42 mm)). The distribution of IHC cell marker analysis of all targeted antibodies ranged from 6.34% to 11.33%. All treatment outcomes between the test groups were comparable. A prolonged retention of LDA was observed from CA microspheres (MC and MP) at both administrations (p < 0.017) and prolonged sustainability of bacteriostatic effect was observed from MC compared to PG after the second administration (p < 0.05).

CONCLUSIONS

Prolonged retention of CA microspheres was observed and the longer bacteriostatic effect was observed from the MC group. Mechanical debridement with adjunct LDA therapy may impede peri-implantitis progression, however, prolonged drug action did not lead to improved treatment outcome.

Locally Applied Slow-Release of Minocycline Microspheres in the Treatment of Peri-Implant Mucositis: An Experimental In Vivo Study

BACKGROUND

The objective of this is preclinical investigation was to evaluate the differential drug sustainability and pharmacodynamic properties of two local minocycline microsphere carriers: chitosan-coated alginate (CA) and poly(meth)acrylate-glycerin (PG).

METHODS

Four dental implants were placed unilaterally in the edentulous mandible of six beagle dogs. Each implant was randomly assigned to receive one of the following four treatments: (i) CA (CA-based minocycline), (ii) placebo (CA substrate without minocycline), (iii) PG (PG-based minocycline) and (iv) control (mechanical debridement only). After inducing peri-implant mucositis, the randomly assigned treatments were administered into the gingival sulcus twice at a 4-week interval using a plastic-tipped syringe. Drug sustainability and pharmacodynamic (clinical, radiographical and cell marker intensity) evaluations were performed after each administration.

RESULTS

The CA microspheres remained longer around the healing abutment compared to the PG microspheres at both administrations and a longer bacteriostatic effect was observed from CA (7.0 ± 5.7 days) compared to PG (1.2 ± 2.6 days). The efficacy of the applied therapies based on clinical, radiographical and histological analyses were comparable across all treatment groups.

CONCLUSIONS

CA microspheres showed longer carrier and bacteriostatic effect sustainability when compared to PG microspheres, however, longer drug sustainability did not lead to improved treatment outcomes.

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.

Intraperiodontal pocket: An ideal route for local antimicrobial drug delivery

Periodontal pockets act as a natural reservoir filled with gingival crevicular fluid for the controlled release delivery of antimicrobials directly. This article reflects the present status of nonsurgical controlled local intrapocket delivery of antimicrobials in the treatment of periodontitis. These sites have specialty in terms of anatomy, permeability, and their ability to retain a delivery system for a desired length of time. A number of antimicrobial products and the composition of the delivery systems, its use, clinical results, and their release are summarized. The goal in using an intrapocket device for the delivery of an antimicrobial agent is the achievement and maintenance of therapeutic drug concentration for the desired period of time. Novel controlled drug delivery system are capable of improving patient compliance as well as therapeutic efficacy with precise control of the rate by which a particular drug dosage is released from a delivery system without the need for frequent administration. These are considered superior drug delivery system because of low cost, greater stability, non-toxicity, biocompatibility, non-immunogenicity, and are biodegradable in nature. This review also focus on the importance and ideal features of periodontal pockets as a drug delivery platform for designing a suitable dosage form along with its potential advantage and limitations. The microbes in the periodontal pocket could destroy periodontal tissues, and a complete knowledge of these as well as an ideal treatment strategy could be helpful in treating this disease.

Multiple applications of flurbiprofen and chlorhexidine chips in patients with chronic periodontitis: a randomized, double blind, parallel, 2-arms clinical trial

AIM

The aim of the present randomized, double blind, parallel, 2-arm clinical study was to examine the safety and efficacy of frequent applications of chlorhexidine chip (CHX) and flurbiprofen chip (FBP) in patients with chronic periodontitis.

METHODS

Sixty patients were randomized into CHX and FBP groups. Following OHI and scaling and root planing (SRP), baseline pocket depth (PD) measurements, gingival recession and bleeding on probing (BOP) were performed and repeated at week 4 and 8. The assigned chip was placed at weeks 0, 1, 2, 3, 5, 7.

RESULTS

Mean PD reduction in the CHX group was 2.08 mm (7.17 to 5.09, p < 0.0001). Mean PD reduction in the FBP group was 2.27 mm (6.72 to 4.45, p < 0.0001). Ninety-seven percentage and 95% of these sites exhibited PD reduction ≥1 mm, while 38% and 34% of the sites exhibited PD ≥3 mm (FBP and CHX, respectively). Clinical attachment level gain (1.66 and 1.95 mm, respectively) was statistically significant (p < 0.0001). Baseline BOP dropped from 98% and 100% to 24% and 30% for the CHX and FBP groups, respectively (p < 0.0001).

CONCLUSION

Frequent applications of CHX and FBP chips resulted in a significant improvement in the periodontal condition in these sites. Furthermore studies will be required to compare this new treatment regimen to SRP or SRP with single chip application.

The Application of Microencapsulation Techniques in the Treatment of Endodontic and Periodontal Diseases

In the treatment of intracanal and periodontal infections, the local application of antibiotics and other therapeutic agents in the root canal or in periodontal pockets may be a promising approach to achieve sustained drug release, high antimicrobial activity and low systemic side effects. Microparticles made from biodegradable polymers have been reported to be an effective means of delivering antibacterial drugs in endodontic and periodontal therapy. The aim of this review article is to assess recent therapeutic strategies in which biocompatible microparticles are used for effective management of periodontal and endodontic diseases. In vitro and in vivo studies that have investigated the biocompatibility or efficacy of certain microparticle formulations and devices are presented. Future directions in the application of microencapsulation techniques in endodontic and periodontal therapies are discussed.

Effect of a controlled release device containing minocycline microspheres on the treatment of chronic periodontitis: A comparative study

INTRODUCTION

Adjunctive therapy with locally delivered antimicrobials has resulted in improved clinical outcomes. The aim of this study was to evaluate the efficacy and safety of locally administered minocycline microspheres (Arestin) in the treatment of chronic periodontitis.

MATERIALS AND METHODS

A total of 60 sites from 15 patients in the age group of 35-50 years, who had periodontal pockets measuring 5-8 mm and had been diagnosed with chronic periodontitis, were selected for the study. The selected groups were randomly assigned to either the control group (group A) or the treatment/test group (group B). Only scaling and root planing were done at the base line visit for the control sites followed by local application of Arestin (1 mg). Clinical parameters such as plaque index, gingival index, and gingival bleeding index were recorded at baseline, day 30, day 90, and day 180 in the selected sites of both the groups. Probing pocket depth also was recorded at baseline, day 90, and day 180 for both the groups.

RESULTS

A statistically significant reduction was observed in both groups. Group B showed better results than Group A and these differences were statistically significant.

CONCLUSION

The results of this study clearly indicate that treatment with scaling and root planing plus minocycline microspheres (Arestin) is more effective and safer than scaling and root planing alone in reducing the signs of chronic periodontitis.

Periodontal infections cause changes in traditional and novel cardiovascular risk factors: results from a randomized controlled clinical trial

BACKGROUND

Chronic infections, such as periodontitis, are associated with increased risk of systemic diseases driven by a persistent low-grade systemic inflammation and metabolic changes. Severity of periodontitis has also been associated with increased systolic blood pressure (BP). However, the issue remains poorly investigated. We aimed to estimate the effect of periodontal therapy on traditional and novel cardiovascular risk factors in systemically healthy individuals who have periodontitis.

METHODS

We enrolled 40 otherwise healthy patients with severe chronic generalized periodontitis in a 6-month pilot intervention trial. Individuals were randomized either to a standard course of periodontal therapy (subgingival scaling and root planing) or an intensive one (including the adjunctive use of a locally delivered antimicrobial, IPT).

RESULTS

Compared to control, IPT produced significant reductions in a cluster of inflammatory markers at 1 (P = .0406) and 2 (P = .0060) months together with an improvement in lipid markers at 2 (P = .0320) and 6 (P = .0432) months after therapy. Intensive periodontal therapy produced greater reductions in IL-6 at 1 (0.4 +/- 0.2 ng/L difference, 95% CI 0.03-0.9, P = .0284) and 2 months (0.3 +/- 0.2 ng/L difference, 95% CI 0.1-0.8, P = .0284), together with decreases in C-reactive protein (0.4 +/- 0.2 mg/L difference, 95% CI 0.01-0.8, P = .0438) and total cholesterol (0.3 +/- 0.1 mmol/L difference, 95% CI 0.04-0.6, P = .0254). Moreover, a 7 +/- 3-mm Hg decrease in systolic BP was observed at 2 months in the IPT group (95% CI 1-12, P = .0211), and this difference was greater in current smokers (14 +/- 5 mm Hg 95% CI 3-25, P = 0.0124). Intensive periodontal therapy subjects exhibited a 1.53% +/- 1.20% (95% CI 1.05-2.24, P = .0290) and 2.00% +/- 1.42% (95% CI 0.98-4.09, P = .0568) decreases in cardiovascular risk scores (Framingham) at 2 and 6 months, respectively, when compared to those in the standard group.

CONCLUSIONS

Our findings suggest that intensive periodontal treatment reduces systemic inflammatory markers and systolic BP, and improves lipid profiles with subsequent changes in cardiovascular risk when compared to standard therapy.

Injectable Polysaccharide Microcapsules for Prolonged Release of Minocycline for the Treatment of Periodontitis

Injectable polysaccharide microcapsules holding minocycline were fabricated from alginate and chitosan for the treatment of periodontitis. The microcapsules were examined for the release and degradation of minocycline, as well as antimicrobial activity. The microcapsules were biodegradable and released minocycline between 10 and 1000 microg ml(-1), which was higher than the usual therapeutic concentration (1-5 microg ml(-1)), for up to 7 days. These microcapsules showed a statistically significant suppression of pathogenic bacteria, such as Prevotella intermedia causing periodontitis. The microcapsules are thus potentially useful for drug delivery for the treatment of periodontitis.

Microflora cultivable from minocycline strips placed in persisting periodontal pockets

OBJECTIVE

The microflora that develops on minocycline strips, used as an adjunct in non-surgical periodontal therapy was studied.

DESIGN AND METHODS

Minocycline (1.4 mg in polycaprolactone vehicle) and control strips were applied into all residual pockets (PD > or = 5mm, > or =2 pockets/subject) of patients with chronic periodontitis 1 month after a course of non-surgical periodontal therapy. Strips were inserted and retained for 3 days, changed to new strips for 3 more days and then removed. Strips were recovered from 14 (eight test, six control) of the 34 participants at day 0 (strip inserted, left for 30 s, removed), days 3 and 6, for (i) anaerobic culture, (ii) coliforms culture, using MacConkey agar, (iii) yeast culture, using Sabouraud's dextrose agar.

RESULTS

The mean anaerobic cfu/strip (x10(5); control/test) were 2/6, 24/2, 11/2 at days 0, 3 and 6, respectively (P > 0.05). The corresponding mean proportion of Gram-negative rods and fusiforms were 27%/21%, 27%/15% and 55%/8%. The proportions of Gram-negative rods on test strips by day 6 were significantly reduced (P < 0.05). A significantly increased prevalence of Streptococcus mitis biovar 1 was found on spent test strips (control versus test; 0% versus 38%, Fisher exact test, P = 0.01). Coliform prevalence at days 0, 3 and 6 on control/test strips were 0/13%, 50%/38% and 50%/13%. Yeasts were occasionally isolated.

CONCLUSIONS

The findings indicated that the minocycline strips but not the control strip supported a microbial colonisation compatible with periodontal health by day 6.

Periodontal therapy using local delivery of antimicrobial agents

Antimicrobial agents, systemic and/or local, are thought by some to be effective agents for treating periodontal infections. Here the authors determine the costs and benefits of local delivery agents for treating periodontal disease. Applying this cost-benefit analysis to patient care, however, will depend upon a clinician's expertise and a patient's value system.