Local delivery of chemotherapeutic agents in periodontal therapy: has its time arrived?

Comparison of simvastatin 1.2% gel and alendronate 1% gel in chronic periodontitis as local drug delivery: A randomized clinical trial

Introduction

Simvastatin (SMV) is used for the treatment of hypercholesterolemia. Long-term systemic administration of SMV has been shown to result in increased bone mineral density. Alendronate (ALN) is known to inhibit osteoclastic bone resorption and has osteostimulative properties.

Aim

To compare percentile changes in gain in clinical attachment level and reduction of pocket depth, and to radiographically evaluate osseous defect fill with subgingival local drug delivery of 1.2% SMV gel and 1% ALN gel.

Materials and Methods

A split-mouth study was conducted with 40 infrabony defects from 20 patients diagnosed with chronic periodontitis. The sites were assigned as test site 1 (SMV gel) or test site 2 (ALN gel). After phase I therapy, a single application of SMV gel or ALN gel was done into periodontal pockets. Clinical periodontal parameters and percentage of bone fill were evaluated at baseline, 3 and 6 months.

Results

There was a statistically significant reduction in pocket depth, plaque index, and bleeding index scores, gain in Clinical attachment level (CAL) and bone defect fill from baseline to 6 months at both sites. On comparison between the groups, test site 2 showed significant improvement in clinical attachment level than in test site 1 at 6-month follow-up. Test site 2 showed more percentage bone fill than test site 1.

Conclusion

Usage of both SMV and ALN gels in periodontal intra bony defects can lead to significant improvements in clinical and radiographic parameters; however, ALN showed better osseous defect fill.

A New Controlled-Release Material Containing Metronidazole and Doxycycline for the Treatment of Periodontal and Peri-Implant Diseases: Formulation and In Vitro Testing

Background

Several locally administered antimicrobials have been studied in the literature as adjunctive or primary treatments for periodontitis and peri-implantitis with conflicting results.

Objective

The aim of this study was twofold: (1) the formulation of a controlled-release material containing metronidazole and doxycycline; (2) an in vitro evaluation of its antibacterial properties against planktonic and biofilm species involved in periodontal and peri-implant diseases.

Methods

Doxycycline (10 mg/ml) and metronidazole (20 mg/ml) were incorporated into a hydroxyethylcellulose-polyvinylpyrrolidone-calcium polycarbophil gel. Three milliliters of gel were dialyzed against Dulbecco's phosphate-buffered saline for 13 days. Antibiotics release at 3, 7, 10, and 13 days was determined spectroscopically. The inhibitory activity of the experimental gel was tested against A. actinomycetemcomitans, S. sanguinis, P. micra, and E. corrodens with an agar diffusion test, an inactivation biofilm test, and a confocal laser scanning microscope study (CLSMS) for S. sanguinis up to 20 days.

Results

After 13 days, the released doxycycline was 9.7% (at 3 days = 1.2 mg; 7 days = 0.67 mg; 10 days = 0.76 mg; 13 days = 0.29 mg), while metronidazole was 67% (30 mg, 6.8 mg, 2.5 mg, and 0.9 mg at the same intervals). The agar diffusion test highlights that the formulated gel was active against tested microorganisms up to 312 h. Quantitative analysis of biofilm formation for all strains and CLSMS for S. sanguinis showed a high growth reduction up to 13 days.

Conclusions

The in vitro efficacy of the newly formulated gel was confirmed both on planktonic species and on bacterial biofilm over a period of 13 days. The controlled-release gel containing metronidazole and doxycycline had an optimal final viscosity and mucoadhesive properties. It can be argued that its employment could be useful for the treatment of periodontal and peri-implant diseases, where conventional therapy seems not successful.

Comparison of clinical effectiveness of single and multiple applications of 1% chlorhexidine varnish (Cervitec Plus) along with scaling and root planing in patients with chronic periodontitis

Background:

Local drug delivery is most commonly used as an adjunct to scaling and root planing (SRP) for the treatment of periodontal disease. Varied success rates have been documented for various vehicles used for intrasite delivery of active therapeutic agents. Recently, varnishes acting as a reservoir of chlorhexidine have shown potential for the management of chronic periodontitis patients. The aim of the present investigation was a comparative evaluation of the clinical effectiveness of single and multiple applications of 1% chlorhexidine and thymol varnish (Cervitec Plus) along with SRP in patients with chronic periodontitis.

Materials and Methods:

The present study included 30 patients with chronic periodontitis divided into three groups based on the number of subgingival applications of chlorhexidine varnish single application (Group A), two applications at a week's interval (Group B), and three applications with 7-day interval in between two applications (Group C). Clinical parameters, namely plaque index (PI), sulcus bleeding index, probing pocket depth (PPD), and relative attachment level (RAL) were recorded at baseline, 1 month and 3 months in all three groups to compare the clinical efficacy.

Results:

A statistically significant reduction was observed in PI, sulcus bleeding index, PPD, and RAL at 1 and 3 months in all the three groups. Greater (though statistically nonsignificant) improvements were observed in Groups B and C.

Conclusion:

Within limitations of the study, it can be concluded that multiple applications of 1% chlorhexidine and thymol varnish (Cervitec Plus) have an added benefit over the single application in the treatment of chronic periodontitis.

Evaluation of an aminobisphosphonate (alendronate) in the management of periodontal osseous defects

Background and Objectives:

Alendronate, an aminobisphosphonate, is capable of inhibiting periodontitis associated osteoclastic activity and hence is effective in protecting the alveolar bone in periodontitis. In the present study, we explored the efficacy of local delivery of alendronate on the alveolar bone following mucoperiosteal flap surgery. This is the first study to use polymer impregnated gel based delivery of alendronate.

Materials and Methods:

A total of 15 patients with chronic periodontitis in the age group of 35 - 55 years, of both sexes, with pocket depth of ≥ 5mm and radiographic evidence of identical osseous defects in the mandibular molar region bilaterally were included in this prospective study. A gel based drug delivery system of Alendronate was formulated. Following surgical flap debridement, 0.1 ml alendronate gel and 0.1 ml placebo gel was placed at the experimental and control sites respectively. Clinical and radiographic parameters were recorded at baseline, three months and six months post surgery.

Results:

Alendronate was more effective in improving clinical and radiographic parameters compared to placebo.

Interpretation and Conclusion:

Alendronate is effective in the management of periodontitis associated bone loss. Gel based local delivery of the drug addresses the critical concern of exposing the patient to adverse effects of systemic administration.

Modified Widman flap and non-surgical therapy using chlorhexidine chip in the treatment of moderate to deep periodontal pockets: A comparative study

INTRODUCTION

It is a well established fact that periodontitis is caused by a group of highly specific microorganisms, organized as a bio-film on the tooth surface. Hence, therapeutic modalities are directed against elimination or adequate suppression of these organisms. Thorough debridement of these sites is possible mainly by scaling and root planing (SRP) and open- flap debridement in deeper sites. Open- flap debridement includes conventional surgical procedures such as the modified Widman flap procedure. Surgical procedures, however, have a number of disadvantages and hence efforts have been on at improving various non-surgical approaches, which are directed more specifically at the microbial nature of periodontal disease. Use of local drug-delivery devices is one such approach. The combined therapy of SRP and local drug delivery has been showing promising results in improving all the parameters in periodontal disease.

MATERIALS AND METHODS

This study compares the clinical, as well as, microbiological results of a split-mouth trial using modified Widman flap and non-surgical therapy of SRP and the use of a controlled release drug-delivery device (Chlorhexidine chip), in the management of moderate to deep pockets.

RESULTS AND CONCLUSION

The results showed that the non-surgical most sites subjected to the non-surgical treatment were found to be maintainable without further deterioration, during the study period.

Novel periodontal drug delivery system for treatment of periodontitis

A conceptually novel periodontal drug delivery system (DDS) is described that is intended for treatment of microbial infections associated with periodontitis. The DDS is a composite wafer with surface layers possessing adhesive properties, while the bulk layer consists of antimicrobial agents, biodegradable polymers, and matrix polymers. The wafers contain poly(lactic-co-glycolic acid) as the main bioerodible component used in the bulk layer and ethyl cellulose applied as a matrix polymer enabling diffusion-controlled release. Starch and other polymers in combination with AgNO(3) serve as coatings adhesive to the teeth. In vitro experiments demonstrate that the wafers are capable of zero-order release of antimicrobial agents such as silver nitrate, benzylpenicillin, and tetracycline, for over 4 weeks.

Sustained release of silver from periodontal wafers for treatment of periodontitis

Periodontal wafers intended to treat the underlying infections in patients with periodontitis have been developed. The wafers consist of poly(lactic-co-glycolic acid) as a primary bioerodible polymeric component, poly(ethylene glycol) as a plasticizer and encapsulation aid, and silver nitrate as the antimicrobial agent. The wafers are capable of sustained in vitro release of bioactive silver for at least 4 weeks. The wafers exhibit silver release that follows erosion kinetics, confirming a bulk erosion/release mechanism. In clinical evaluation, sustained release of silver at bactericidal levels for at least 21 days is observed. Staining of hard and soft tissues due to the released silver is minimal and reversible.