Clinical and microbiological effects of controlled-release locally delivered minocycline in periodontitis

An Antibiotic-Loaded Silicone-Hydrogel Interpenetrating Polymer Network for the Prevention of Surgical Site Infections

Surgical site infections (SSIs) are among the most frequent healthcare-associated infections, resulting in high morbidity, mortality, and cost. While correct hygiene measures and prophylactic antibiotics are effective in preventing SSIs, even in modern healthcare settings where recommended guidelines are strictly followed, SSIs persist as a considerable problem that has proven hard to solve. Surgical procedures involving the implantation of foreign bodies are particularly problematic due to the ability of microorganisms to adhere to and colonize the implanted material and form resilient biofilms. In these cases, SSIs may develop even months after implantation and can be difficult to treat once established. Locally applied antibiotics or specifically engineered implant materials with built-in antibiotic-release properties may prevent these complications and, ultimately, require fewer antibiotics compared to those that are systemically administered. In this study, we demonstrated an antimicrobial material concept with intended use in artificial vascular grafts. The material is a silicone-hydrogel interpenetrating polymer network developed earlier for drug-release catheters. In this study, we designed the material for permanent implantation and tested the drug-loading and drug-release properties of the material to prevent the growth of a typical causative pathogen of SSIs, Staphylococcus aureus. The novelty of this study is demonstrated through the antimicrobial properties of the material in vitro after loading it with an advantageous combination, minocycline and rifampicin, which subsequently showed superiority over the state-of-the-art (Propaten) artificial graft material in a large-animal study, using a novel porcine tissue-implantation model.

Supra and subgingival application of antiseptics or antibiotics during periodontal therapy

Periodontal diseases (gingivitis and periodontitis) are characterized by inflammatory processes which arise as a result of disruption of the balance in the oral ecosystem. According to the current S3 level clinical practice guidelines, therapy of patients with periodontitis involves a stepwise approach that includes the control of the patient's risk factors and the debridement of supra and subgingival biofilm. This debridement can be performed with or without the use of some adjuvant therapies, including physical or chemical agents, host modulating agents, subgingivally locally delivered antimicrobials, or systemic antimicrobials. Therefore, the main aim of this article is to review in a narrative manner the existing literature regarding the adjuvant application of local agents, either subgingivally delivered antibiotics and antiseptics or supragingivally applied rinses and dentifrices, during the different steps in periodontal therapy performed in Europe.

Controlled release devices as adjuvants in nonsurgical periodontal therapy: A systematic review

Controlled release devices (CRD) have been widely studied regarding their application in periodontal therapy. Therefore, the present study aims to evaluate the use and effectiveness of controlled-release devices in nonsurgical periodontal therapy through a systematic review. The research was carried out in six different databases, namely: Online Medical Literature Search and Analysis System (Medline-PubMed), Web of Science, Science Direct, Scopus, Scielo, and Google Scholar. The descriptors "Delayed-Action Preparation," "Therapeutics," and "Periodontitis," were used with their EntryTerms and connected through the Boolean operators AND and OR. A total of 2847 studies were found, and after applying the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist flowchart, 34 were selected using the eligibility criteria. After that, the qualitative results were tabulated and the risk of bias in each of them was evaluated. It can be observed that the use of CRD presents itself as a successful alternative for adjuvant treatment to periodontal therapy, a fact due to its availability and local concentration in the crevicular fluid. However, further clinical research is still needed to develop devices that are effective, with an easy and quick application, as well as available at a good cost-benefit ratio.

The efficacy of minocycline hydrochloride ointment versus iodoform gauze for alveolar osteitis: A prospective cohort study

Background

Alveolar osteitis (AO) is one of the most commonly encountered complication following tooth extraction, however, to date there is no standard methods of prevention and treatment. The study aims to investigate the efficiency of minocycline hydrochloride ointment (MHO) for the treatment of alveolar osteitis compared with traditional treatment with iodoform gauze (IG).

Methods/design

STROBE checklist was followed to report this study. All patients underwent tooth extraction either in our department or other hospitals, whom presented with postoperative pain, were screened out to meet the inclusion and exclusion criteria of this study about AO. Patients who fulfilled the inclusion criteria were enrolled in our prospective cohort study, and MHO or IG was administered. The Visual analog scale scores were used to assess the pain score of patients. The healing status of the extraction sockets was followed up. Differences in responses between groups were analyzed using Mann-Whitney U tests. Chi-square test was performed to explore the differences in the teeth position of AO.

Results

Of 41,371 patients underwent tooth extraction with post-operative follow-up in our departments, only 20 patients (0.05%) suffered from AO. 31 patients with AO, whose teeth were extracted in other places, were also enrolled. The incidence of AO was significantly higher in third molars than other teeth (P < 0.01). In 28 patients that were treated with MHO, the pain was relieved substantially on day 3 and almost painless on day 7. And only 25% of cases required dressing change more than once. Whilst 23 patients treated with IG, the pain was relieved on day 5, and 56.5% of cases required multiple dressing change. The difference between the two groups of VAS scores had statistical significance during treatment at 8 h, 24 h, 3d, 5d, and 7d. No allergic reaction or further infection occurred.

Conclusion

MHO has a safer and higher therapeutic effect in the treatment of AO compared with traditional treatment with IG. MHO may become a preferred treatment modality for AO.

Supplementary information

The online version contains supplementary material available at 10.1186/s12903-022-02468-9.

Drug-Loaded Chitosan Scaffolds for Periodontal Tissue Regeneration

Chitosan is a natural anionic polysaccharide with a changeable architecture and an abundance of functional groups; in addition, it can be converted into various shapes and sizes, making it appropriate for a variety of applications. This article examined and summarized current developments in chitosan-based materials, with a focus on the modification of chitosan, and presented an abundance of information about the fabrication and use of chitosan-derived products in periodontal regeneration. Numerous preparation and modification techniques for enhancing chitosan performance, as well as the uses of chitosan and its metabolites, were reviewed critically and discussed in depth in this study. Chitosan-based products may be formed into different shapes and sizes, considering fibers, nanostructures, gels, membranes, and hydrogels. Various drug-loaded chitosan devices were discussed regarding periodontal regeneration.

Controlled release of iodine from cross-linked cyclodextrin metal-organic frameworks for prolonged periodontal pocket therapy

Effective therapeutic system to periodontitis was designed using cross-linked cyclodextrin metal-organic framework (COF) as carrier for iodine and further suspended in hydroxyethyl cellulose gel as I2@COF-HEC hydrogel. Inclusion of iodine within the COF was demonstrated by SR-FTIR spectral and characteristic DSC and TGA changes. Molecular modelling identified the interaction of iodine with both COF central cavity and individual cyclodextrin moieties of COF. In vitro results of study demonstrated that iodine release in artificial saliva from I2@COF-HEC hydrogel could be extended up to 5 days, which was slower than I2@COF particles. Using an in vivo rat model of periodontitis, micro-computed tomography of alveolar bone morphology demonstrated that I2@COF-HEC hydrogel showed similar effects in decreasing periodontal pocket depth and alveolar bone resorption to minocycline ointment, a periodontitis antibiotic. The I2@COF-HEC hydrogel is a novel local delivery device of iodine as a broad spectrum antimicrobial use for treatment of periodontitis.

Adjunctive effect of locally delivered antimicrobials in periodontitis therapy: A systematic review and meta-analysis

AIM

To answer the following PICOS question: in adult patients with periodontitis, which is the efficacy of adjunctive locally delivered antimicrobials, in comparison with subgingival debridement alone or plus a placebo, in terms of probing pocket depth (PPD) reduction, in randomized clinical trials with at least 6 months of follow-up.

MATERIAL AND METHODS

A systematic search was conducted: 59 papers, reporting 50 different studies, were included. Data on clinical outcome variables changes were pooled and analysed using weighted mean differences (WMDs) and 95% confidence intervals (CI), and prediction intervals (PI), in case of significant heterogeneity.

RESULTS

Statistically significant differences were observed, in 6- to 9-month studies, for PPD (WMD = 0.365, 95% CI [0.262; 0.468], PI [-0.29; 1.01]) and clinical attachment level (CAL) (WMD = 0.263, 95% CI [0.123; 0.403], PI [-0.43; 0.96]). For long-term studies, significant differences were observed for PPD (WMD = 0.190, 95% CI [0.059; 0.321]), but not for CAL. For adverse events, no differences were observed. Results were affected by study design (split-mouth versus parallel studies) and assessment (full- or partial-mouth), as well as by the formulation tested.

CONCLUSIONS

The use adjunctive locally delivered antimicrobials in periodontitis therapy results in statistically significant benefits in clinical outcomes, without relevant side effects.

Clinical and microbiological effects of adjunctive local delivery of minocycline (Periocline®) in patients receiving supportive periodontal therapy: a pilot study

Purpose

This study aimed to evaluate the clinical and microbiological efficacy of adjunctive local delivery of minocycline (Periocline^®) in patients receiving supportive periodontal therapy (SPT) after initial treatment.

Methods

The participants were 16 men and 8 women (age, 20–65 years) who had at least 15 natural teeth, underwent SPT for more than 1 year due to chronic periodontitis, had 4 or more periodontal pocket sites deeper than 5 mm, and showed >25% gingival bleeding on probing (BoP). They were randomly assigned to the test and control groups. In the test group, mechanical debridement and local antibiotic delivery were performed for all periodontal sulci/pockets; in the control group, mechanical debridement and saline irrigation were performed. In patients who underwent SPT for more than 1 year, clinical and microbiological examinations were performed at baseline and 1 and 3 months after SPT. The clinical examination included an assessment of the periodontal pocket depth, clinical attachment level, plaque index, and BoP. Microbial tests were performed using real-time polymerase chain reaction; the relative ratios of Porphyromonas gingivalis and Fusobacterium nucleatum were determined.

Results

Both groups showed significant improvements in clinical parameters at 1 and 3 months from baseline; there were no significant changes between months 1 and 3. Intergroup differences were insignificant. The microbiological analysis revealed no significant differences in P. gingivalis and F. nucleatum ratios across time points. While intergroup differences were insignificant, there was a tendency for the P. gingivalis and F. nucleatum ratios to decrease in the test group.

Conclusions

Mechanical debridement in patients receiving maintenance therapy resulted in clinically significant improvement; the effectiveness of additional local delivery of antibiotics was not significant. The ratios of P. gingivalis and F. nucleatum showed a tendency to decrease in the test group, although it was not significant.

Potential of chitosan-based carrier for periodontal drug delivery

Periodontal diseases are chronic infectious diseases and are a major oral health burden. With the progress in the understanding of etiology, epidemiology and pathogenesis of periodontal diseases coupled with the understanding of the polymicrobial synergy in the dysbiotic oral microbial flora, several new therapeutic targets have been identified. The strategies to curb bacterial growth and production of factors that gradually destroy the tissue surrounding and supporting the teeth have been the cornerstone for inhibiting periodontitis. Systemic administration of antibiotics for the treatment of periodontitis have shown several drawbacks including: inadequate antibiotic concentration at the site of the periodontal pocket, a rapid decline of the plasma antibiotic concentration to sub-therapeutic levels, the development of microbial resistance due to sub-therapeutic drug levels and peak-plasma antibiotic concentrations which may be associated with various side effects. These obvious disadvantages have evoked an interest in the development of localized drug delivery systems that can provide an effective concentration of antibiotic at the periodontal site for the duration of the treatment with minimal side effects. A targeted sustained release device which could be inserted in the periodontal pocket and prolong the therapeutic levels at the site of action at a much lower dose is the need of the hour. Chitosan, a deacetylated derivative of chitin has attracted considerable attention owing to its special properties including antimicrobial efficacy, biodegradability, biocompatibility and non-toxicity. It also has the propensity to act as hydrating agent and display tissue healing and osteoinducting effect. The aim of this review is to shine a spotlight on the chitosan based devices developed for drug delivery application in the effective treatment of various periodontal disorders. The chitosan based carriers like fibers, films, sponge, microparticles, nanoparticles, gels that have been designed for sustained release of drug into the periodontal pocket are highlighted.

Assessment of clinical efficacy of locally delivered 0.2% Thymoquinone gel in the treatment of periodontitis

Objectives

To evaluate the potential benefits of local application of Thymoquinone gel as an adjunctive to scaling and root planing (SRP) in subjects with chronic periodontitis.

Material and methods

Twenty subjects with 40 test sites were selected according to inclusion and exclusion criteria. They were further divided into 2 groups. Group I comprised of study subjects (Thymoquinone in addition to SRP) and Group II comprised of control subjects (only SRP). Clinical parameters such as Plaque Index (PI), Gingival Index (GI), Probing Pocket Depth (PPD), Relative Attachment Level (RAL), were monitored at baseline and 6 weeks post operatively. Alkaline phosphatase (ALP) levels in gingival crevicular fluid (GCF) were evaluated at baseline and 6 weeks post operatively using microcapillaries. In addition antimicrobial efficacy of Thymoquinone was evaluated against 3 bacteria using antimicrobial strains.

Results

Statistically highly significant reduction was observed in PI, GI and PPD, rise in RAL and GCF ALP level in both the groups at 6 weeks from baseline. On comparison between Group I and Group II, former demonstrated statistically significant reduction in PPD, GCF-ALP levels and rise in RAL but statistically no significant differences were observed in PI and GI at 6 weeks. On microbiological assessment of 0.2% Thymoquinone gel, it was observed to be sensitive against P. gingivalis, A. actinomycetemcomitans and P. intermedia.

Conclusion

Significant changes in clinical and biochemical parameters were achieved in the current study. Hence, it is concluded that intracrevicular application of 0.2% Thymoquinone gel could be a beneficial adjunct to SRP in treating chronic periodontitis.

Dysbiosis Contributes to Arthritis Development via Activation of Autoreactive T Cells in the Intestine

OBJECTIVE

The intestinal microbiota is involved in the pathogenesis of arthritis. Altered microbiota composition has been demonstrated in patients with rheumatoid arthritis (RA). However, it remains unclear how dysbiosis contributes to the development of arthritis. The aim of this study was to investigate whether altered composition of human intestinal microbiota in RA patients contributes to the development of arthritis.

METHODS

We analyzed the fecal microbiota of patients with early RA and healthy controls, using 16S ribosomal RNA-based deep sequencing. We inoculated fecal samples from RA patients and healthy controls into germ-free arthritis-prone SKG mice and evaluated the immune responses. We also analyzed whether the lymphocytes of SKG mice harboring microbiota from RA patients react with the arthritis-related autoantigen 60S ribosomal protein L23a (RPL23A).

RESULTS

A subpopulation of patients with early RA harbored intestinal microbiota dominated by Prevotella copri; SKG mice harboring microbiota from RA patients had an increased number of intestinal Th17 cells and developed severe arthritis when treated with zymosan. Lymphocytes in regional lymph nodes and the colon, but not the spleen, of these mice showed enhanced interleukin-17 (IL-17) responses to RPL23A. Naive SKG mouse T cells cocultured with P copri-stimulated dendritic cells produced IL-17 in response to RPL23A and rapidly induced arthritis.

CONCLUSION

We demonstrated that dysbiosis increases sensitivity to arthritis via activation of autoreactive T cells in the intestine. Autoreactive SKG mouse T cells are activated by dysbiotic microbiota in the intestine, causing joint inflammation. Dysbiosis is an environmental factor that triggers arthritis development in genetically susceptible mice.

Antibiotics/antimicrobials: systemic and local administration in the therapy of mild to moderately advanced periodontitis

This review gives an update of the current scientific evidence on the efficacy of the adjunctive use of systemic and local antibiotics/antimicrobials in the treatment of periodontitis. In particular, it addresses whether their use can improve the results of nonsurgical mechanical therapy in mild-to-moderate forms of the disease. Large numbers of randomized clinical trials and systematic reviews with meta-analyses have clearly established that adjunctive systemic antibiotics, combined with mechanical debridement, offer clinical improvements additional to those obtained with scaling and root planing alone. These effects are more pronounced in aggressive periodontitis and in initially deep pockets, whereas more limited additional improvements, of 0.3 mm for additional pocket reduction and 0.2 mm for additional clinical attachment gain, have been documented for moderately deep sites (4-6 mm) in patients with chronic periodontitis. The marginal clinical benefit in patients with moderate disease has to be balanced against possible side effects. Notably, it has to be realized that an increasing number of warnings have been articulated against the unrestricted use of antibiotics in treating periodontal diseases because of the emerging global public health issue of bacterial resistance. The effects of the adjunctive local administration of antimicrobials have also been very well documented in several systematic reviews. Overall, in persistent or recurrent localized deep sites, the application of antimicrobials by sustained-delivery devices may offer a benefit of an additional 0.4 mm in pocket depth reduction and 0.3 mm in clinical attachment level gain. In conclusion, the slight additional benefits of adjunctive antimicrobials, which were shown for moderate forms of periodontitis, have to be balanced against their side effects and therefore their prescription should be limited as much as possible.

The risk reduction of recurrent periodontal pathogens of local application minocycline HCl 2% gel, used as an adjunct to scaling and root planing for chronic periodontitis treatment

Background

The aim of this study was to evaluate the clinical and microbiological effects of local application minocycline HCl 2% gel, used as an adjunct to scaling and root planing (SRP) for treatment of chronic periodontitis (CP). CP is an inflammation of periodontal tissue that is caused mainly by bacterial infection, where periodontal destruction such as loss of attachment and bone destruction occurred.

Methods

A total of 81 subjects with moderate to severe periodontitis whose baseline clinical attachment loss (CAL) was ≥4 mm were randomly assigned to receive SRP alone (control group, N=39) or SRP followed by four times of local application of minocycline HCl gel (Periocline) once a week (test group, N=42). Pocket depth, CAL, and papilla bleeding index were examined at baseline, 21 days, 2, 3, and 6 months. Subgingival plaque samples were collected with sterile curettes and were analyzed by real-time polymerase chain reaction for the presence of three periodontal pathogens (Porphyromonas gingivalis [P.g.], Tannerella forsythia [T.f.], and Treponema denticola [T.d.]) at baseline, 2, 3, and 6 months.

Results

The number of bacteria was reduced in both groups at 2 months after baseline (SRP treatment). The changes (2–6 months) in T.d. and T.f. counts in the test group were significantly lower than those in the control group. In the control group, a significant regrowth of P.g., T.f., and T.d. was observed from 2 to 6 months and of P.g. and T.f. from 3 to 6 months. On the other hand, in the test group, the number of the three bacteria did not significantly increase during the 6-month period.

Conclusion

The results showed that local application of minocycline, used as an adjunct to SRP, was effective for suppressing regrowth of periodontal pathogens, suggesting its risk reduction of recurrent periodontal pathogens in CP.

Systematic review and meta-analysis on the nonsurgical treatment of chronic periodontitis by means of scaling and root planing with or without adjuncts

BACKGROUND

Conduct a systematic review and meta-analysis on nonsurgical treatment of patients with chronic periodontitis by means of scaling and root planing (SRP) with or without adjuncts.

METHODS

A panel of experts convened by the American Dental Association Council on Scientific Affairs conducted a search of PubMed (MEDLINE) and Embase for randomized controlled trials of SRP with or without the use of adjuncts with clinical attachment level (CAL) outcomes in trials at least 6 months in duration and published in English through July 2014. The authors assessed individual study bias by using the Cochrane Risk of Bias Tool and conducted meta-analyses to obtain the summary effect estimates and their precision and to assess heterogeneity. The authors used funnel plots and Egger tests to assess publication bias when there were more than 10 studies. The authors used a modified version of the US Preventive Services Task Force methods to assess the overall level of certainty in the evidence.

RESULTS

The panel included 72 articles on the effectiveness of SRP with or without the following: systemic antimicrobials, a systemic host modulator (subantimicrobial-dose doxycycline), locally delivered antimicrobials (chlorhexidine chips, doxycycline hyclate gel, and minocycline microspheres), and a variety of nonsurgical lasers (photodynamic therapy with a diode laser, a diode laser, neodymium:yttrium-aluminum-garnet lasers, and erbium lasers).

CONCLUSIONS AND PRACTICAL IMPLICATIONS

With a moderate level of certainty, the panel found approximately a 0.5-millimeter average improvement in CAL with SRP. Combinations of SRP with assorted adjuncts resulted in a range of average CAL improvements between 0.2 and 0.6 mm over SRP alone. The panel judged the following 4 adjunctive therapies as beneficial with a moderate level of certainty: systemic subantimicrobial-dose doxycycline, systemic antimicrobials, chlorhexidine chips, and photodynamic therapy with a diode laser. There was a low level of certainty in the benefits of the other included adjunctive therapies. The panel provides clinical recommendations in the associated clinical practice guideline.

Minocycline Ointment as a Local Drug Delivery in the Treatment of Generalized Chronic Periodontitis - A Clinical Study

INTRODUCTION

The primary goal in periodontal therapy includes removal of the etiological factors by mechanical periodontal treatment, which sometimes fail to eliminate the anaerobic infection at the base of the pocket and requires adjuvant chemical therapy.

AIM

The aim of the study was to evaluate the effectiveness of 2% minocycline ointment when used as an adjunct to periodontal flap surgery and post-operative maintenance period for the treatment of generalized chronic periodontitis.

MATERIALS AND METHODS

The study included 30 subjects comprising of 60 posterior sextants in a split mouth design in which 30 sextants were treated as experimental and 30 sextants as control with a probing pocket depth≥6mm. In Group A (experimental group) 30 sextants were treated with open flap debridement followed by the application of minocycline ointment as a local drug delivery. In Group B (control group) 30 sextants were treated with open flap debridement alone. Minocycline hydrochloride ointment was applied on the 0 day and 3(rd) month. The clinical parameters such as plaque index, probing pocket depth, clinical attachment level and gingival bleeding index were recorded at 0 day, 3(rd) month and 6(th) month in both the groups. Paired and unpaired t-test were used to compare the means of the two groups.

RESULTS

When Group A and Group B were compared, Group A showed significantly greater reduction in gingival bleeding index, probing pocket depth and gain in clinical attachment level than Group B, from 0 day to 3 months and from 0 day to 6 months. Group A showed significant reduction in plaque index than Group B when they were compared at 6 months.

CONCLUSION

The results demonstrate that there was significant reduction in the clinical parameters with improvement in the periodontal status on application of minocycline ointment as an adjunct to periodontal flap surgery in generalized chronic periodontitis.

Periodontal treatment with topical antibiotics improves glycemic control in association with elevated serum adiponectin in patients with type 2 diabetes mellitus

OBJECTIVES

Chronic inflammation of periodontitis aggravates glycemic control in type 2 diabetic patients through aggravation of insulin resistance. Increased or decreased release of various inflammatory mediators, such as high sensitivity C-reactive protein (hs-CRP), tumor necrosis factor (TNF)-α, interleukin (IL)-6 and adipokines, such as adiponectin, leptin, and resistin, are presumed to be responsible for developing and progressing insulin resistance. The purpose of this study was to examine the effects of periodontal treatment on glycemic control, serum inflammatory mediators and adipokines in type 2 diabetes patients with periodontitis.

METHODS

Twenty-one type 2 diabetic patients with periodontitis received periodontal treatment with topical antibiotics (intervention group) and 8 patients did not receive periodontal treatment (control group). Periodontal examination, including probing pocket depth (PPD) and bleeding on probing (BOP), and blood sampling were performed at baseline, 2 and 6 months after periodontal treatments. Glycated hemoglobin (HbA1c), hs-CRP, TNF-α, IL-6, adiponectin, leptin, and resistin were analyzed.

RESULTS

In the intervention group, improvements of PPD and BOP, decrease in HbA1c and elevation of serum adiponectin were observed, while in the control group, all parameters were not changed. Generalized linear model revealed that changes of serum adiponectin and TNF-α and change of BOP correlated significantly with the reduction of HbA1c at 6 months after periodontal treatments.

CONCLUSION

The results demonstrated that periodontal treatment improves periodontal status and glycemic control with elevation of serum adiponectin in type 2 diabetic patients. The results suggest that HbA1c is reduced by amelioration of insulin resistance due to elevated serum adiponectin after periodontal treatments.

A chlorhexidine-loaded biodegradable cellulosic device for periodontal pockets treatment

Absorbent points widely used in endodontic therapy were transformed into bioresorbable chlorhexidine delivery systems for the treatment of the periodontal pocket by preventing its recolonization by the subgingival microflora. These paper points (PPs) were first oxidized to promote their resorption, then grafted with β-cyclodextrin (CD) or maltodextrin (MD) in order to achieve sustained delivery of chlorhexidine. We investigated the oxidation step parameters through the time of reaction and the nitric and phosphoric acid ratios in the oxidizing mixture, and then the dextrin grafting step parameters through the time and temperature of reaction. A first selection of the appropriate functionalization parameters was undertaken in relation to the degradation profile kinetics of the oxidized (PPO) and oxidized-grafted samples (PPO-CD and PPO-MD). Samples were then loaded with chlorhexidine digluconate (digCHX), a widely used antiseptic agent in periodontal therapy. The release kinetics of digCHX from PPO-CD and PPO-MD samples were compared to PP, PPO and to PerioChip(®) (a commercial digCHX containing gelatine chip) in phosphate buffered saline (pH 7.4) by ultraviolet spectrophotometry. The cytocompatibility of the oxidized-grafted PP was demonstrated by cell proliferation assays. Finally, the disc diffusion test from digCHX loaded PPO-MD samples immersed in human plasma was developed on pre-inoculated agar plates with four common periodontal pathogenic strains: Fusobacterium nucleatum, Prevotella melaninogenica, Aggregatibacter actinomycetem comitans and Porphyromonas gingivalis. To conclude, the optimized oxidized-dextrin-grafted PPs responded to our initial specifications in terms of resorption and digCHX release rates and therefore could be adopted as a reliable complementary periodontal therapy.

Comparative evaluation of locally delivered minocycline and metronidazole in the treatment of periodontitis

Objective:

The aim of this study was to evaluate and compare the efficacy of subgingivally delivered Minocycline microspheres and 25% Metronidazole gel when used as an adjunct to scaling and root planing (SRP) in the treatment of chronic periodontitis.

Materials and Methods:

A randomized, controlled, single center study was conducted involving 60 sites in 20 patients suffering from moderate to advanced chronic periodontitis. Each patient contributed three sites which were randomized to three treatment groups: SRP + insertion of Minocycline microspheres at day 1 (Group A), SRP + insertion of Metronidazole gel at day 1 and at day 7 (Group B), and SRP alone (Group C). Gingival index (GI), plaque index (PI), probing pocket depth (PPD), and clinical attachment level (CAL) were recorded at day 1, 1 month, and 3 months post therapy.

Results:

All treatments showed significant reductions in PPD and CAL at 1 and 3 months when compared to baseline values (P < 0.001). At 3 months, sites treated with minocycline showed an additional reduction in PPD of 0.85 ± 0.03 mm, significantly greater than SRP alone. Differences in mean PPD reduction between Group B and Group C and between Group A and Group B were not significant. At 3 months, difference in CAL gain between Group A and C was 0.50 ± 0.45, which was statistically significant and between Group B and C was 0.35 ± 0.11, which was not found to be statistically significant (P = 0.20). Differences in relative CAL between Group A and Group B were also not found to be statistically significant (P = 0.53).

Conclusion:

The results concluded that treatment with Minocycline microspheres and Metronidazole gel improve PPD and CAL in patients with periodontitis compared to SRP alone.

A systematic review on the effects of local antimicrobials as adjuncts to subgingival debridement, compared with subgingival debridement alone, in the treatment of chronic periodontitis

AIMS

To update the existing scientific evidence on the efficacy of local antimicrobials as adjuncts to subgingival debridement in the treatment of chronic periodontitis.

MATERIAL AND METHODS

Fifty-six papers were selected, reporting data from 52 different investigations. All the studies reported changes in probing pocket depth (PPD) and clinical attachment level (CAL) and most in plaque index (PlI) and/or bleeding on probing (BOP). Meta-analyses were performed with the data retrieved from the studies fulfilling the inclusion criteria.

RESULTS

The overall effect of the subgingival application of antimicrobials was statistically significant (p = 0.000) for both changes in PPD and CAL with a weighted mean difference (WMD) of -0.407 and -0.310 mm respectively. No significant differences occurred for changes in BOP and PlI. Subgingival application of tetracycline fibres, sustained released doxycycline and minocycline demonstrated a significant benefit in PPD reduction (WMD between 0.5 and 0.7 mm). The rest of the tested outcomes demonstrated a high heterogeneity. The local application of chlorhexidine and metronidazole showed a minimal effect when compared with placebo (WMD between 0.1 and 0.4 mm).

CONCLUSIONS

The scientific evidence supports the adjunctive use of local antimicrobials to debridement in deep or recurrent periodontal sites, mostly when using vehicles with proven sustained release of the antimicrobial.

Improved drug loading and antibacterial activity of minocycline-loaded PLGA nanoparticles prepared by solid/oil/water ion pairing method

Background

Low drug entrapment efficiency of hydrophilic drugs into poly(lactic-co-glycolic acid) (PLGA) nanoparticles is a major drawback. The objective of this work was to investigate different methods of producing PLGA nanoparticles containing minocycline, a drug suitable for periodontal infections.

Methods

Different methods, such as single and double solvent evaporation emulsion, ion pairing, and nanoprecipitation were used to prepare both PLGA and PEGylated PLGA nanoparticles. The resulting nanoparticles were analyzed for their morphology, particle size and size distribution, drug loading and entrapment efficiency, thermal properties, and antibacterial activity.

Results

The nanoparticles prepared in this study were spherical, with an average particle size of 85–424 nm. The entrapment efficiency of the nanoparticles prepared using different methods was as follows: solid/oil/water ion pairing (29.9%) > oil/oil (5.5%) > water/oil/water (4.7%) > modified oil/water (4.1%) > nano precipitation (0.8%). Addition of dextran sulfate as an ion pairing agent, acting as an ionic spacer between PEGylated PLGA and minocycline, decreased the water solubility of minocycline, hence increasing the drug entrapment efficiency. Entrapment efficiency was also increased when low molecular weight PLGA and high molecular weight dextran sulfate was used. Drug release studies performed in phosphate buffer at pH 7.4 indicated slow release of minocycline from 3 days to several weeks. On antibacterial analysis, the minimum inhibitory concentration and minimum bactericidal concentration of nanoparticles was at least two times lower than that of the free drug.

Conclusion

Novel minocycline-PEGylated PLGA nanoparticles prepared by the ion pairing method had the best drug loading and entrapment efficiency compared with other prepared nanoparticles. They also showed higher in vitro antibacterial activity than the free drug.

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.

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.

Dynamics of the inflammatory response after murine spinal cord injury revealed by flow cytometry

Spinal cord injury (SCI) triggers a robust inflammatory response that contributes in part to the secondary degeneration of spared tissue. Here, we use flow cytometry to quantify the inflammatory response after SCI. Besides its objective evaluation, flow cytometry allows for levels of particular markers to be documented that further aid in the identification of cellular subsets. Analyses of blood from SCI mice for CD45 (common leukocyte antigen), CD11b (complement receptor-3), Gr-1 (neutrophil/monocyte marker), and CD3 (T-cell marker) revealed a marked increase in circulating neutrophils (CD45(high):Gr-1(high)) at 12 hr compared with controls. Monocyte density in blood increased at 24 hr, and in contrast, lymphocyte numbers were significantly decreased. Mirroring the early increase in neutrophils within the blood, flow analysis of the spinal cord lesion site revealed a significant (P < 0.01) and maintained increase in blood-derived leukocytes (CD45(high):CD11b(high)) from 12 to 96 hr compared with sham-injured and naive controls. Importantly, this technique clearly distinguishes blood-derived neutrophils (CD45:Gr-1(high):F4/80(negative)) and monocyte/macrophages (CD45(high)) from resident microglia (CD45(low)) and revealed that the majority of the blood-derived infiltrate were neutrophils. Our results highlight an assumed, but previously uncharacterized, marked and transient increase in leukocyte populations in blood early after SCI followed by the orchestrated invasion of neutrophils and monocytes into the injured cord. In contrast to mobilization of neutrophils, SCI induces lymphopenia that may contribute negatively to the overall outcome after spinal cord trauma.

Local Drug Delivery in the Treatment of Periodontal Diseases: Assessing the Clinical Significance of the Results

BACKGROUND

Local drug delivery can be used in the management of periodontal patients. However, statistically significant responses to therapy recorded in clinical trials may not be clinically significant.

METHODS

Controlled clinical trials were selected that assessed the capability of local drug delivery to improve periodontal health.

RESULTS

Several local drug delivery systems employed as monotherapies improved periodontal health and provided results that were not statistically significantly different than attained with scaling and root planing (SRP) alone. In contrast, many local drug delivery devices when used as adjuncts to SRP provided a statistically significant enhancement of parameters commonly used to monitor periodontal status. However, mean improvements with respect to probing depth reduction or gain of clinical attachment were often limited to tenths of millimeters. Several devices also achieved specific criteria that can be used to identify clinically significant findings (e.g., number of sites with probing depth reduction >or=2 mm). However, there are conflicting data with respect to the ability of local drug delivery to enhance results of SRP at deep probing sites, and there is limited information relative to its capability to inhibit disease progression or enhance osseous repair in infrabony defects.

CONCLUSION

The decision to use local drug delivery during active treatment or maintenance should be based upon clinical findings, responses to therapy recorded in the literature, desired clinical outcomes, and the patient's dental and medical history.

Impact of local adjuncts to scaling and root planing in periodontal disease therapy: a systematic review

BACKGROUND

Chronic periodontitis affects many adults in the United States, some severely enough to threaten tooth loss. Of particular clinical importance is whether scaling and root planing (SRP) accompanied by a local adjunctive therapeutic agent improves outcomes over time compared to SRP alone. The adjunctive therapeutic agents investigated include: tetracycline, minocycline, metronidazole, a group of other antibiotics, chlorhexidine, and a group of antimicrobials. Primary outcomes considered are reductions in probing depth (PD) and gains in clinical attachment level (CAL).

METHODS

RTI-UNC Evidence-Based Practice Center staff searched MEDLINE (1966 through December 2002) and EMBASE (through February 2002) to identify clinical trials published in English that 1) involved adults with chronic periodontitis but no serious comorbidities; 2) tested one or more chemical antimicrobial agents as an adjunct to SRP alone or with a placebo; 3) had a concurrent control group that received the same SRP as the treatment group; 4) reported outcomes for specified, fixed time periods; and 5) if multiple antimicrobials were tested, reported outcomes for each agent separately. We performed qualitative analyses and meta-analyses of PD and CAL effect sizes when the necessary data were available from at least three studies at 6-month follow-up.

RESULTS

Among the locally administered adjunctive antimicrobials, the most positive results occurred for tetracycline, minocycline, metronidazole, and chlorhexidine. Adjunctive local therapy generally reduced PD levels. Differences between treatment and SRP-only groups in the baseline-to-follow-up period typically favored treatment groups but usually only modestly (e.g., from about 0.1 mm to nearly 0.5 mm) even when the differences were statistically significant. Effects for CAL gains were smaller and statistical significance less common. The marginal improvements in PD and CAL were a fraction of the improvement from SRP alone.

CONCLUSIONS

Whether such improvements, even if statistically significant, are clinically meaningful remains a question. A substantial agenda of future research to address this and other issues (e.g., costs, patient-oriented outcomes) is suggested.

Efficacy of subgingivally applied minocycline in the treatment of chronic periodontitis

BACKGROUND

The use of adjunctive minocycline with mechanical debridement in treating periodontitis has been widely studied using different methods. However, the results from these studies are equivocal.

OBJECTIVE

The purpose of this study was to clarify the efficacy of the adjunctive use of subgingival minocycline application plus scaling/root planing as compared with the results of one episode of scaling/root planing in the treatment of chronic periodontitis.

METHODS

Fifteen patients were enrolled in this split-mouth clinical trial. Probing depth, clinical attachment loss, gingival index, and bleeding on probing were evaluated at the baseline before scaling/root planing and 6, 10, 14, and 18 weeks later according to a single-blind protocol. The amount of interleukin-1beta (interleukin-1beta pg/site) at each lesion was also simultaneously measured in gingival crevicular fluid in a parallel comparison design. After full-mouth baseline measurements and scaling/root planing, 78 lesions with a residual mean probing depth of 5 mm at anterior teeth were selected and equally distributed in either right or left sites based on a split-mouth symmetrical design and randomly assigned to one of two treatment groups (with or without minocycline administration, n = 39 for each group).

RESULTS

Probing depth significantly decreased from the baseline (week 0) to week 6 after scaling/root planing (p < 0.05) in both groups, but there was no statistically significant difference between the two groups (p > 0.05). However, at weeks 10, 14, and 18, the experimental group showed significantly greater improvement in pocket reduction than the control group (p < 0.05). Similarly, both groups also showed significant decreases in gingival index scores from weeks 0-6 (p < 0.05), but gingival index reductions at weeks 10, 14, and 18 were statistically significant in favor of the experimental group (p < 0.05). The experimental group had more attachment gain than the control group at weeks 14 and 18 (p < 0.05). Values of interleukin-1beta (pg/site) at the experimental sites were significantly reduced at weeks 10, 14, and 18, as compared to values at control sites (p < 0.01). Finally, the incidence of bleeding on probing showed no differences between the two groups for any time interval (p > 0.05).

CONCLUSIONS

In this 18-week clinical trial, the results suggested that scaling/root planing with adjunctive subgingival administration of minocycline ointment has a significantly better and prolonged effect compared to scaling/root planing alone on the reduction of probing depth, clinical attachment loss, gingival index, and interleukin-1beta content, but not on bleeding on probing.

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.

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.

Can we successfully maintain risk patients?

The most fundamental premise in the current view of periodontal disease is that not all individuals are at equal risk for disease and disease progression. Studies reveal that about 5-20% of the population is at risk for severe disease progression. The purpose of this paper is to define at-risk patients, review risk factors and indicators of disease progression, and outline an evidence-based strategy that includes both self-care and professional care for maintaining periodontal health. Risk factors/risk indicators considered include history of previous disease, increased pocket depth and loss of clinical attachment, frequency of dental care, specific bacterial pathogens, and systemic/environmental host factors such as smoking, diabetes mellitus, genetics, and stress. Because host factors may have more influence on disease progression than periodontal pathogens, personal and professional maintenance care must include the role of the host in periodontal disease progression. By examining the evidence surrounding these complex issues, dentists and dental hygienists are able to determine the extent to which evidence supports available approaches to maintain periodontal health and control disease progression.

Local anti-infective therapy: pharmacological agents. A systematic review

BACKGROUND

It is well recognized that periodontal diseases are bacterial in nature. An essential component of therapy is to eliminate or control these pathogens. This has been traditionally accomplished through mechanical means (scaling and root planing [SRP]), which is time-consuming, difficult, and sometimes ineffective. Over the past 20 years, locally delivered, anti-infective pharmacological agents, most recently employing sustained-release vehicles, have been introduced to achieve this goal.

RATIONALE

This systematic review evaluates literature-based evidence in an effort to determine the efficacy of currently available anti-infective agents, with and without concurrent SRP, in controlling chronic periodontitis.

FOCUSED QUESTION

In patients with chronic periodontitis, what is the effect of local controlled-release anti-infective drug therapy with or without SRP compared to SRP alone on changes in clinical, patient-centered, and adverse outcomes?

SEARCH PROTOCOL

MEDLINE, the Cochrane Central Trials Register, and Web of Science were searched. Hand searches were performed of the Journal of Clinical Periodontology, Journal of Periodontology, and Journal of Periodontal Research. Searches were performed for articles published through April 2002. In addition, investigators contacted editors of the above-mentioned journals and companies sponsoring research on these agents for related unpublished data and studies in progress.

SELECTION CRITERIA

INCLUSION CRITERIA

Studies included randomized controlled clinical trials (RCT), and case-controlled and cohort studies at least 3 months long. Therapeutic interventions had to include 1) SRP alone; 2) local anti-infective drug therapy and SRP; or 3) local anti-infective drug therapy alone. Included studies had to report patient-based mean values and measures of variation for probing depth (PD) and/or clinical attachment levels (CAL) for both test and control groups.

EXCLUSION CRITERIA

Studies were excluded if they: 1) included data from a previously published article; 2) included daily rinsing with chlorhexidine (CHX); or 3) had unclear descriptions of randomization procedures, examiner masking, or concomitant therapies.

DATA COLLECTION AND ANALYSIS

For the meta-analysis, PD and CAL were expressed as summary mean effects with 95% confidence intervals (CI) for the effect, and analyzed using a standardized difference between SRP alone and experimental agent groups. The results were assessed with both fixed-effects and random-effects models. Studies were ranked according to the York system.

MAIN RESULTS

1. Thirty-two studies were included (28 RCT, 2 cohort, and 2 case-control), incorporating a total patient population of 3,705 subjects. 2. Essentially all studies reported substantial reductions in gingival inflammation and bleeding indices, which were similar in both control and experimental groups. 3. A meta-analysis completed on 19 studies that included SRP and local sustained-release agents compared with SRP alone indicated significant adjunctive PD reduction or CAL gain for minocycline (MINO) gel, microencapsulated MINO, CHX chip and doxycycline (DOXY) gel during SRP compared to SRP alone. 4. Use of antimicrobial irrigants or anti-infective sustained-release systems as an adjunct to SRP does not result in significant patient-centered adverse events.

REVIEWERS' CONCLUSIONS

1. In some populations, anti-infective agents in a sustained-release vehicle alone can reduce PD and bleeding on probing (BOP) equivalent to that achieved by SRP alone. 2. No evidence was found for an adjunctive effect on reduction of PD and BOP of therapist-delivered CHX irrigation during SRP compared to SRP alone. 3. Additional RCTs are needed which evaluate the effectiveness of these therapies in all forms of periodontitis. 4. The study protocol for future RCTs should include appropriate statistical analyses and complete data sets to facilitate future evidence-based reviews. 5. Alternative surrogate parameters to PD and CAL need to be identified and validated such as microbial, inflammatory, or tissue-destructive markers that could be used in conjunction with clinical parameters to help determine the patient's response to emerging technologies that target the infectious and/or inflammatory aspects of periodontitis. 6. Future Phase IV clinical trials should be designed that evaluate local anti-infective therapies in conjunction with SRP in a manner consistent with current standards of care and evaluate cost-effectiveness. 7. The use of local anti-infective agents in at-risk patient populations and for the treatment of at-risk disease sites needs to be validated in randomized controlled clinical trials. 8. Several local anti-infective agents combined with SRP appear to provide additional benefits in PD reduction and CAL gain compared to SRP alone. The decision to use local anti-infective adjunctive therapy remains a matter of individual clinical judgment, the phase of treatment, and the patient's status and preferences.

Meta-analysis of local tetracycline in treating chronic periodontitis

BACKGROUND

Meta-analysis was used to assess the clinical efficacy of local delivery of tetracycline alone or as an adjunct to conventional mechanical therapy in patients with chronic periodontitis.

METHODS

Studies were identified in MEDLINE and others sources. Meta-analyses were performed on the basis of probing depth (PD) at baseline, type of antimicrobial used, and experimental and control regimens (i.e., tetracycline plus scaling and root planing [SRP] versus SRP, tetracycline versus SRP, and tetracycline versus placebo, or no treatment). The effect of local tetracycline was evaluated for follow-up times of 4, 8, 12, 16, 24, and 36 weeks. Sensitivity analysis was performed according to antimicrobial delivery mode (irrigation, fibers, strips). A random effects model was used.

RESULTS

The literature search identified 29 studies that met our inclusion criteria and were entered Into the meta-analysis. A significant mean reduction in PD for the combined tetracycline and SRP was observed regardless of initial probing depth and independently to the duration of follow-up. Tetracycline alone did not perform better than SRP, whereas they performed significantly better than placebo. Differences in improvement of attachment level (AL) were substantially similar to those encountered for PD.

CONCLUSIONS

Our results documented that local. delivery of tetracycline improves the clinical outcomes of traditional treatment and should be considered particularly as an adjunct to SRP. Considerations regarding the adverse effects of widespread use of tetracycline should be taken into account when choosing a therapeutic strategy of chronic periodontitis.

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.

Ethyl cellulose and polyethylene glycol-based sustained-release sparfloxacin chip: an alternative therapy for advanced periodontitis

This study reports the development of a sustained-release system of sparfloxacin for use in the treatment of periodontal disease. A sustained-release sparfloxacin device was formulated, based on ethyl cellulose (EC) 10 cps, polyethylene glycol (PEG) 4000, and diethyl phthalate (DEPh). It will hereafter be called the sparfloxacin chip (SRS chip). The chip has dimensions of 10 mm length, 2 mm width, and 0.5 mm thickness. The in vitro drug release pattern and clinical evaluation of the formulations were studied. Reports of the short-term clinical study show that the use of the SRS chip may cause complete eradication of the pathogenic bacteria in the periodontal pockets of patients who have chronic generalized periodontitis. In this clinical study, the baseline and follow-up measurements of various clinical indices, such as oral hygiene index(es), plaque index, sulcular depth component of periodontal disease index, gingival crevicular fluid flow measurement, and dark field microscopic examinations of oral pathogens in plaque samples were studied. Significant improvements were observed in many parameters of the treatment group compared with the placebo group.

Effect of locally delivered minocycline microspheres on markers of bone resorption

BACKGROUND

Gingival crevicular fluid (GCF) biomarkers associated with bone resorption may be useful to determine periodontal disease status and response to therapy. The pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen (ICTP), a bone-specific degradation product, and interleukin 1-beta (IL-1), a potent bone-resorptive cytokine, have both been associated with periodontal disease activity. Minocycline is a tetracycline derivative possessing antimicrobial effects on periodontal pathogens and inhibitory properties on matrix metalloproteinases (MMPs) associated with tissue destruction. The aim of this study was to evaluate the effect of periodontal treatment in the form of scaling and root planing (SRP) and locally administered minocycline microspheres on the GCF levels of ICTP and IL-1.

METHODS

Forty-eight chronic periodontitis patients were randomly assigned to 2 groups (SRP plus subgingival application of vehicle control [SRP + V], or SRP plus subgingival application of minocycline microspheres [SRP + M]) and monitored at 8 sites per subject at baseline and 1, 3, and 6 months. Four shallow (PD < or = 3 mm) and 4 deep (PD > or = 5 mm) sites were evaluated for both marker levels and for probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP). Eight periodontally healthy control subjects with no probing depths >3 mm and no loss of attachment were also monitored at the same time intervals. GCF levels of ICTP and IL-1 were determined using radioimmunoassay and enzyme-linked immunosorbent assay techniques, respectively.

RESULTS

Significant differences (P<0.001) in GCF levels of ICTP and IL-1 were found between deep and shallow sites at all time points in both treatment groups. In addition, healthy subjects demonstrated significantly reduced levels of both markers compared to both shallow and deep sites in periodontitis patients (P <0.001). Only the SRP + M treated patients exhibited significant reductions (P <0.05) in both ICTP and IL-1 levels 1 month after treatment. Furthermore, the SRP + M group demonstrated significantly lower IL-1 levels (P <0.02) at 1 month compared to the SRP + V group.

CONCLUSIONS

Results of this study indicate that GCF levels of ICTP and IL-1 correlate with clinical measures of periodontal disease and may aid in assessing disease status and response to periodontal therapy. Furthermore, local administration of minocycline microspheres led to a potent short-term reduction in GCF IL-1 levels. Additional studies are needed to address whether repeated administration of scaling and root planing along with minocycline microspheres will achieve long-term reductions in GCF ICTP and IL-1 levels.

Treatment of periodontitis by local administration of minocycline microspheres: a controlled trial

BACKGROUND

Periodontitis is an inflammatory condition of tooth-supporting tissues that is usually treated by mechanical removal of plaque and microorganisms that adhere to teeth. This treatment, known as scaling and root planing, is not optimally effective. Adjunctive therapy with locally delivered antimicrobials has resulted in improved clinical outcomes such as probing depth reduction. This article reports on the efficacy and safety of locally administered microencapsulated minocycline.

METHODS

Seven hundred forty-eight (748) patients with moderate to advanced periodontitis were enrolled in a multi-center trial and randomized to 1 of 3 treatment arms: 1) scaling and root planing (SRP) alone; 2) SRP plus vehicle; or 3) SRP plus minocycline microspheres. The primary outcome measure was probing depth reduction at 9 months. Clinical assessments were performed at baseline and 1, 3, 6, and 9 months.

RESULTS

Minocycline microspheres plus scaling and root planing provided substantially more probing depth reduction than either SRP alone or SRP plus vehicle. The difference reached statistical significance after the first month and was maintained throughout the trial. The improved outcome was observed to be independent of patients' smoking status, age, gender, or baseline disease level. There was no difference in the incidence of adverse effects among treatment groups.

CONCLUSIONS

Scaling and root planing plus minocycline microspheres is more effective than scaling and root planing alone in reducing probing depths in periodontitis patients.

Periodontal disease as a specific, albeit chronic, infection: diagnosis and treatment

Periodontal disease is perhaps the most common chronic infection in adults. Evidence has been accumulating for the past 30 years which indicates that almost all forms of periodontal disease are chronic but specific bacterial infections due to the overgrowth in the dental plaque of a finite number of mostly anaerobic species such as Porphyromonas gingivalis, Bacteroides forsythus, and Treponema denticola. The success of traditional debridement procedures and/or antimicrobial agents in improving periodontal health can be associated with the reduction in levels of these anaerobes in the dental plaque. These findings suggest that patients and clinicians have a choice in the treatment of this overgrowth, either a debridement and surgery approach or a debridement and antimicrobial treatment approach. However, the antimicrobial approach, while supported by a wealth of scientific evidence, goes contrary to centuries of dental teaching that states that periodontal disease results from a "dirty mouth." If periodontal disease is demonstrated to be a risk factor for cardiovascular disease and stroke, it will be a modifiable risk factor since periodontal disease can be prevented and treated. Since the antimicrobial approach may be as effective as a surgical approach in the restoration and maintenance of a periodontally healthy dentition, this would give a cardiac or stroke patient and his or her physician a choice in the implementation of treatment seeking to improve the patient's periodontal condition so as to reduce and/or delay future cardiovascular events.

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.

The antimicrobial treatment of periodontal disease: changing the treatment paradigm

Over the last 100 years, methods of surgical periodontal treatment have enjoyed a history of success in improving oral health. The paradigm of care is based on the "non-specific plaque hypothesis"--that is, the overgrowth of bacterial plaques cause periodontal disease, and the suppression of this overgrowth reduces disease risk. The central feature of this approach to care is the removal of inflamed gingival tissue around the teeth to reduce periodontal pocket depth, thereby facilitating plaque removal by the dentist and by the patient at home. Over the last 30 years, with the recognition that periodontal disease(s) is caused by specific bacteria and that specific antimicrobial agents can reduce or eliminate the infection, a second paradigm has developed. This new paradigm, the "specific plaque hypothesis", focuses on reducing the specific bacteria that cause periodontal attachment loss. The contrast between the two paradigms can be succinctly stated as follows: The antimicrobial therapy reduces the cause, while the surgical therapy reduces the result of the periodontal infection. The specific plaque hypothesis has two important implications. First, with the increasing attention to evidence-based models for prevention, treatment, outcome assessment, and reimbursement of care, increasing attention and financial effort will be channeled into effective preventive and treatment methods. Second, the recent observations that periodontal infections increase the risk of specific systemic health problems, such as cardiovascular disease, argue for the prevention and elimination of these periodontal infections. This review highlights some of the evidence for the specific plaque hypothesis, and the questions that should be addressed if antimicrobial agents are to be used responsively and effectively.

A 15-month evaluation of the effects of repeated subgingival minocycline in chronic adult periodontitis

BACKGROUND

A double-blind, randomized, parallel, comparative study was designed to evaluate the long-term safety and efficacy of subgingivally administered minocycline ointment versus a vehicle control.

METHODS

One hundred four patients (104) with moderate to severe adult periodontitis (34 to 64 years of age; mean 46 years) were enrolled in the study. Following scaling and root planing, patients were randomized to receive either 2% minocycline ointment or a matched vehicle control. Study medication was administered directly into the periodontal pocket with a specially designed, graduated, disposable applicator at baseline; week 2; and at months 1, 3, 6, 9, and 12. Scaling and root planing was repeated at months 6 and 12. Standard clinical variables (including probing depth and attachment level) were evaluated at baseline and at months 1, 3, 6, 9, 12, and 15. Microbiological sampling using DNA probes was done at baseline; at week 2; and at months 1, 3, 6, 9, 12, and 15.

RESULTS

Both treatment groups showed significant and clinically relevant reductions in the numbers of each of the 7 microorganisms measured during the entire 15-month study period. When differences were detected, sites treated with minocycline ointment always produced statistically significantly greater reductions than sites which received the vehicle control. For initial pockets > or =5 mm, a mean reduction in probing depth of 1.9 mm was seen in the test sites, versus 1.2 mm in the control sites. Sites with a baseline probing depth > or =7 mm and bleeding index >2 showed an average of 2.5 mm reduction with minocycline versus 1.5 mm with the vehicle. Gains in attachment (0.9 mm and 1.1 mm) were observed in minocycline-treated sites, with baseline probing depth > or =5 mm and > or =7 mm, respectively, compared with 0.5 mm and 0.7 mm gain at control sites. Subgingival administration of minocycline ointment was well tolerated.

CONCLUSIONS

Overall, the results demonstrate that repeated subgingival administration of minocycline ointment in the treatment of adult periodontitis is safe and leads to significant adjunctive improvement after subgingival instrumentation in both clinical and microbiologic variables over a 15-month period.

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

The concept of locally delivering chemotherapeutic agents to the periodontal pocket as a method to treat periodontal disease has been studied for over 20 years. A number of locally delivered chemotherapeutic agents in periodontal therapy are either currently available or under investigation. Clinical efficacy derives from sustained-release technology to maintain an effective concentration of drug within the periodontal pocket for a clinically relevant length of time. Studied drugs have mainly been antimicrobials, both antibiotics and antiseptics. Most agents have been tested as adjuncts to scaling and root planing; a few have been studied as stand-alone monotherapies. Collectively, the data indicate that the use of locally delivered antimicrobials as adjuncts results in a significant increase in the reduction of probing depth compared with scaling and root planing alone. In other trials, results in reducing probing depth following the use of stand-alone locally delivered antimicrobials have been equivalent to those of scaling and root planing over a specified time. This Symposium was organized to present the current state-of-the-art with regard to the use of locally delivered antimicrobials in the treatment of periodontal disease. 5 experts in the field who have had considerable experience in studying locally delivered antimicrobials presented data. These speakers reviewed the clinical findings regarding efficacy of 5 different antimicrobial agents. An ensuing panel discussion was to consider treatment recommendations for locally delivered antimicrobials.

The use of locally delivered minocycline in the treatment of chronic periodontitis. A review of the literature

Tetracyclines are frequently used in the treatment of periodontitis; however, emergence of resistant bacterial strains has decreased the utility of these drugs. At present, there are a lot of data in the literature from which one can draw conclusions regarding the use of local drug delivery. This paper reviews the utility and different systems of local delivery of minocycline, a semisynthetic tetracycline, in the treatment of periodontitis.

Subgingival controlled release of antimicrobial agents in the treatment of periodontal disease

Local drug delivery of antimicrobics by sustained release delivery systems can be used to treat periodontal disease. Advantages of these systems may include biodegradation of the system, maintaining high levels of antibiotic in the gingival crevicular fluid (GCF) for a sustained period of time and ease of use with high patient acceptance. This review will identify human in vivo clinical and microbiological studies. Sustained release formulations, application methods, clinical results and microbiological effects are discussed.

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

Clinical and microbiological effects of subgingival delivery of 10% minocycline-loaded (MC), bioabsorbable microcapsules were examined in 15 adult periodontitis patients. Patients received oral hygiene instruction 2 weeks prior to the study. At baseline (day 0) all teeth received supragingival scaling (SC); 2 quadrants received no further treatment and 1 quadrant received subgingival scaling and root planning (SRP). In the fourth quadrant, the tooth with the deepest probing sites (at least 1 site > or = 5 mm) was treated with minocycline microcapsules. The sites were evaluated at baseline and weeks 1, 2, 4, and 6. Clinical indices included bleeding on probing (BOP), probing depths (PD), and attachment loss (AL). Microbiological evaluations included percent morphotypes by phase-contrast microscopy; cultivable anaerobic, aerobic, and black-pigmented Bacteroides (BPB); and percent Porphyromonas gingivalis, Prevotella intermedia, Eikenella corrodens, and Actinomyces viscosus by indirect immunofluorescence. In the SC + MC group, BOP, PD, and AL were significantly reduced from baseline for weeks 1 to 6. BOP in the SC + MC group was significantly reduced compared to the SRP group from weeks 2 to 6. In the SC + MC group the percent of spirochetes and motile rods decreased and the percent of cocci increased after 1 week. The increased cocci and decreased motile rods were statistically greater at weeks 4 and 6 in the SC + MC group compared to the SRP group. This study demonstrates that local subgingival delivery of 10% minocycline-loaded microcapsules as an adjunct to scaling results in reduction in the percent sites bleeding on probing greater than scaling and root planning alone and induces a microbial response more favorable for periodontal health than scaling and root planing.