Minocycline slow-release formulation effect on subgingival bacteria

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.

In vitro assessment of the antimicrobial activity of tetracycline hydrochloride diluted in three different vehicles against Porphyromonas gingivalis, Prevotella intermedia, and Fusobacterium nucleatum

Background:

The development and progression of periodontal diseases is a result of the dynamic interaction of microorganisms within their habitat, and changes in this habitat generate a dysbiotic state. Fusobacterium nucleatum and Prevotella intermedia are bridging microorganisms between the pioneer communities and other microorganisms responsible for periodontitis such as Porphyromonas gingivalis. Tetracycline hydrochloride (TTC-HCl) is commonly used as a coadjutant in periodontal treatment in the form of an antiseptic. However, there are no clear dilution or concentration protocols.

Objective:

This study aimed to evaluate the in vitro antimicrobial activity of TTC-HCl diluted in sterile water, saline solution, and 2% lidocaine with epinephrine 1:80,000 at concentration of 125, 250, and 500 mg, at three time points– 30, 60, and 120 s – on P. intermedia, F. nucleatum, and P. gingivalis using the Kelsey–Maurer technique.

Materials and Methods:

The antimicrobial activity of TTC-HCl was evaluated at the proposed concentrations and times, dissolved in the different vehicles at pH 1.9 and 7.0, on F. nucleatum, P. intermedia, and P. gingivalis. The Kelsey–Maurer test was used to verify the presence or absence of colony-forming units. Each test was performed in triplicates with its respective viability controls.

Results:

Inhibition of F. nucleatum, P. intermedia, and P. gingivalis was achieved with TTC-HCl at all concentrations, dissolved in distilled water, saline solution, and 2% lidocaine with epinephrine 1:80,000 for all times.

Conclusions:

The results show that TTC-HCl is a good antimicrobial alternative against F. nucleatum, P. intermedia, and P. gingivalis regardless of the vehicle in which it was dissolved, concentration, pH, or time used in this investigation.

Meeting the challenges and clinical requirements for dental regeneration; the New Zealand experience

Disease and trauma leading to tooth loss and destruction of supporting bone is a significant oral handicap, which may be addressed through surgical therapies that aim to regenerate the lost tissue. Whilst complete regeneration of teeth is still aspirational, regeneration of supporting structures (dental pulp, cementum, periodontal ligament, bone) is becoming commonplace, both for teeth and for titanium dental implants that are used to replace teeth. Most grafting materials are essentially passive, however the next generation of oral regenerative devices will combine non-antibiotic antimicrobials and/or osteogenic or inductive factors and/or appropriate multipotential stem cells. The review gives an overview of the approaches taken, including fabrication of novel scaffolds, incorporation of growth factors and cell-based therapies, and discusses the preclinical animal models we employ in the development pathway.

Clinicomicrobiological evaluation of the efficacy of local delivery of moxifloxacin and ibuprofen gel as an adjunct to scaling and root planing in chronic periodontitis patients

Aims:

To evaluate the clinical and microbiological effects of local drug delivery of moxifloxacin and ibuprofen gel as an adjunct to conventional periodontal therapy in chronic periodontitis patients.

Subjects and Methods:

Twenty patients with moderate-to-severe chronic generalized periodontitis with probing pocket depth (PPD) of ≥5 mm and <8 mm were randomly assigned to one of the following two treatment modalities: scaling and root planing (SRP) group and moxifloxacin and ibuprofen combination gel as an adjunct to SRP group. Clinical parameters include plaque index (PI), gingival index (GI), probing depths and clinical attachment level (CAL) that were recorded at baseline and 1 and 3 months after the treatment, and microbiologic assessment was done using dark-field microscopy.

Results:

A statistically significant difference in mean PI and GI scores and reduction in PPD and gain in CAL were observed at different study intervals with greater difference in the test group. On microbiological examination, the percentage of cocci increased, while a statistically significant decrease in the mean percentage of bacilli and spirochetes was observed in both groups at given intervals. In-vitro dissolution showed controlled release of both the drugs.

Conclusions:

Among the two treatment modalities, treatment with moxifloxacin and ibuprofen local delivery as an adjunct to SRP gave superior results in clinical and microbiological parameters compared to SRP group.

Effects of Antimicrobial Photodynamic Therapy and Local Administration of Minocycline on Clinical, Microbiological, and Inflammatory Markers of Periodontal Pockets: A Pilot Study

Objective

We evaluated the efficacies of antimicrobial photodynamic therapy (aPDT) and minocycline ointment (MO) on clinical and bacteriological markers and the local host inflammatory response.

Materials and Methods

A total of 30 patients with chronic periodontitis were randomly assigned to two groups. Selected periodontal pockets (probing depth 5-7 mm with bleeding on probing) were treated with aPDT or MO. Measurements of clinical parameters and the collection of gingival crevicular fluid (GCF) and subgingival plaque were performed at baseline, and at 1 and 4 weeks after treatment. Quantification of periodontopathic bacteria in the sulcus and a multiplex bead immunoassay of ten inflammatory cytokines in the GCF were performed.

Results

Local MO administration exhibited a significant decrease in scores for clinical parameters (P < 0.01) and a significant reduction in bacterial counts (P < 0.01) and interleukin-1β and interferon-γ levels at 1 and 4 weeks after treatment (P < 0.01). No significant changes were observed in the aPDT group, except in clinical parameters.

Conclusions

Although our study had some limitations, we found that while local administration of MO may slightly help to improve clinical, microbiological, and crevicular cytokine levels in periodontal pockets, aPDT did not show any effects. This trial is registered with the UMIN Clinical Trials Registry UMIN000013376.

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.

Statins: A new era in local drug delivery

Periodontitis is an inflammatory disease of the supporting tissues of the teeth, caused by a group of specific microorganisms. Aggressive forms of periodontitis can be localized or generalized. The concept that localized problem sites may be treated by local drug delivery appears attractive as the antimicrobial agent is delivered within periodontal pockets and the therapy is targeted on specific pathogenic microorganisms. Periodontitis can result in bone resorption creating bony defects, which may cause tooth loss. Various drugs have been studied using local delivery to improve the periodontal health and to achieve periodontal regeneration. Local delivery of antimicrobial agents using controlled release systems should be considered as adjunctive to mechanical debridement for the treatment of localized forms of periodontal destruction. Pharmacological agents offer great promise in this direction. Simvastatin, used for the treatment of hypercholesterolemia, is a universally accepted and relatively inexpensive drug. Local application of simvastatin has been shown to stimulate bone formation in rodents both in vitro and in vivo and in human periodontal ligament cells in vitro. This article reviews the effects of simvastatin as a local delivery and examines its potential role in periodontal regenerative therapy.

Minocycline containing local drug delivery system in the management of chronic periodontitis: A randomized controlled trial

Background:

The role of chemotherapeutic agents in periodontal therapy as adjuncts to mechanical debridement maybe justified by the inherent limitations of mechanical therapy. The aim of this study was to evaluate the long term efficacy of a locally delivered 2% minocycline gel as an adjunct to scaling and root planing in managing chronic periodontitis.

Materials and Methods:

This was a randomized controlled trial using a split-mouth study design. Twenty two pairs of sites with similar probing depths were randomly allocated to test and control groups. All sites received thorough scaling and root planing followed by minocycline gel application in the test sites. Probing depths, relative attachment levels, plaque index, and microbiological parameters were evaluated for both the groups over a 9-month period.

Results:

Overall parameters improved from baseline in both the test and control groups. For most parameters, the differences between test and control groups were not significant at different time intervals. The probing depth values in the test group at six (3.64±0.83 mm) and nine months (3.81±0.79 mm) were significantly less than control group(4.24±0.95 mm at six and 4.63±0.94 mm at nine months), these differences being significant at P<0.05 and <0.01, respectively. At the end of nine months, the number of non-motile bacilli in test group (21.65±3.74) were significantly less than control group (25.5±3.01), the difference being significant at P<0.02.

Conclusion:

The overall view of results in our investigation did not show any significant advantage of using 2% minocycline gel over scaling and root planning as an effective local drug delivery system and calls for further clinical trials to objectively evaluate its adjunctive in treatment of periodontitis.

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.

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.

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.

Clinical and microbiological effects of subgingival administration of two active gels on persistent pockets of chronic periodontitis patients

OBJECTIVES

The present controlled, single-blind study was performed to assess and compare the clinical healing and the microbiological findings following repeated intrasulcular applications of 1% metronidazole or 1% chlorhexidine gels in persistent periodontal pockets previously treated by scaling and root planing (SRP).

MATERIAL AND METHODS

Sixty-three systemically healthy subjects, 25 males and 38 females (mean age 48.4+/-7.2 years), diagnosed for chronic periodontitis were enrolled in this study. They underwent SRP and received oral hygiene instructions (OHI). Three months later, at baseline, a single persistent pocket with a probing depth (PD) of 5-9 mm was chosen as the experimental site in each patient; the subjects were stratified into three matched experimental groups on the basis of the treatment to be performed, which consisted of the subgingival administration of 1% metronidazole gel (MG, n=19), 1% chlorhexidine gel (CG, n=20) or placebo gel (PG, n=24). The treatments consisted of four repeated administrations of subgingival gels, each separated by 7 days, starting at the baseline. Clinical assessment was performed at the baseline and at the 180-day follow-up, after the end of treatment. For microbiological evaluations, subgingival plaque was sampled from the experimental sites at baseline, prior to the first subgingival gel administration, and at 7, 15, 30 and 90 days after the end of the treatment (days 28, 36, 51 and 111 from baseline).

RESULTS

Plaque accumulation did not change significantly in all three groups. Bleeding on probing and clinical attachment levels reduced in the MGs and CGs only. PD was significantly reduced by the same amount in all experimental groups. In the MGs and CGs a remarkable reduction in the frequencies of detection of several periodontopathic micoorganisms was recorded after the treatment. The same was not seen for the PGs.

CONCLUSIONS

Subgingival administration of MG or CG, both at 1%, may have a role in the management of persistent pockets during chronic periodontitis.

Measurement of peptidase activity and evaluation of effectiveness of administration of minocycline for treatment of dogs with periodontitis

OBJECTIVE

To determine clinical, enzymatic, and microbiologic effects of controlled-release localized administration of minocycline on dogs with periodontitis.

ANIMALS

Five adult Beagles with periodontitis.

PROCEDURE

After tooth scaling and root planing, 2 treatment, 1 placebo, and 1 control site were selected for each dog. Treatment sites (n = 10) received a periodontal formulation of minocycline hydrochloride, placebo sites (5) received ointment without minocycline, and control sites (5) did not receive ointment. Treatments were administered 4 times at weekly intervals. Peptidase activity and clinical and microbiologic effects were evaluated and compared among sites for 17 weeks.

RESULTS

Bleeding of the gums on probing (BOP) and pocket depth (PD) improved at the treatment site and were maintained for 13 weeks after treatment. However, BOP and PD in placebo and control sites increased from weeks 9 to 17 Peptidase activity in the periodontal pocket decreased noticeably from week 1 to 17, compared with baseline values for the treatment site. However, peptidase activity for placebo and control sites increased and were above baseline values on week 9 and week 13, respectively. Total bacterial counts decreased by 90% for treatment sites and remained at that value for 13 weeks. However, for placebo and control sites, bacterial counts increased and reached the baseline value on week 17.

CONCLUSIONS AND CLINICAL RELEVANCE

Increased peptidase activity is correlated with the progression of periodontitis in dogs. Treatment with minocycline, using a localized delivery system, was effective in dogs for at least 13 weeks after cessation of drug administration.

Local and chronic application of PTH accelerates tooth movement in rats

We previously reported that whereas systemic continuous infusion of parathyroid hormone (PTH) accelerated orthodontic tooth movement, systemic but intermittent injection of PTH did not increase the rate of tooth movement. Analysis of these data suggested that continuous administration of PTH could be applicable for orthodontic therapy. In the present study, we investigated whether local and chronic application of PTH(1-34) would accelerate orthodontic tooth movement. To increase the residence time of PTH in the injected area, we used methylcellulose (MC) gel (2% W/V) for a slow-release formulation of PTH. MC gel containing PTH (PTH-MC) continuously released biologically active PTH into the acceptor medium for more than 72 hrs in vitro. When male rats received a local injection of PTH-MC into the subperiosteum in the mesio-palatal region of the maxillary first molar (M1) every other day, M1 movement, which was mesially drawn by an orthodontic coil spring attached to the maxillary incisors, was accelerated in a dose-dependent manner. PTH-MC injection at 1 microg/400 g body weight caused a 1.6-fold increase in the rate of tooth movement. The acceleration of tooth movement by PTH-MC injection was marked on days 6, 9, and 12. Local injection of PTH dissolved in saline without MC did not significantly accelerate tooth movement on day 6 or later. Histological examination revealed active osteoclastic bone resorption and a widened periodontal space on the compression side of the periodontal tissue in the PTH-MC-injected rats. These results suggest that local injection of PTH in a slow-release formulation is applicable to orthodontic therapy.

Evaluation of the regenerative effect of a 25% doxycycline-loaded biodegradable membrane for guided tissue regeneration

BACKGROUND

Biodegradable materials have been successfully utilized for guided tissue regeneration (GTR) and local delivery systems (LDS) because they are biocompatible, less cytotoxic, and do not require removal. Several studies have demonstrated that tetracyclines (TCs), when applied topically, stimulated osteogenesis in experimental bone defects. The purpose of this study was to evaluate the regenerative effect of a 25% doxycycline-loaded biodegradable GTR membrane (Doxy-M) in dogs.

METHODS

Doxy-M was made by coating the inner surface of a biodegradable membrane (BD-M) with 25% doxycycline. Five male mongrel dogs with 20 created osseous defects were enrolled. The plain BD-M was used as the control membrane. Either Doxy-M or BD-M was applied in 20 randomly selected defects (10 Doxy-M, 10 BD-M) for 12 weeks with the GTR technique. The histometric analysis was evaluated with the following parameters: defect height (DH), apical extension of junctional epithelium (AEJP), new cementum height (NCH), new bone height (NBH), and new bone area (NBA).

RESULTS

The Doxy-M-treated defects showed more pronounced new bone formation and less crestal bone resorption than the BD-M-treated defects. There were no statistically significant differences between the two groups in DH, AEJP, and NCH. Statistically significantly larger NBH (P <0.05) and NBA (P<0.005) were seen in the Doxy-M-treated defects.

CONCLUSIONS

The results strongly suggest that Doxy-M may have a beneficial effect on osteogenesis to favor periodontal regeneration.

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.

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.

Clinical and antimicrobial effects of a single episode of subgingival irrigation with tetracycline HCl or chlorhexidine in deep periodontal pockets

15 adults, each providing 4 non-adjacent untreated periodontal pockets with a probing depth (PD) exceeding 6 mm, volunteered for a randomized, split-mouth, double-blind, clinical study evaluating subgingival irrigation with chlorhexidine (CHX) or tetracycline HCl (TTC). The study protocol included oral hygiene instructions followed by scaling and root planing. Experimental and immediately adjacent teeth did not receive instrumentation. The 4 deep periodontal pockets in each patient were assigned to be irrigated with 150 ml CHX (0.12%), TTC (10 or 50 mg/ml; TTC10, TTC50), or sterile saline (control) in a single episode. Post-irrigation mechanical plaque control was supported by 2x daily CHX rinses throughout the 12-week observation interval. Recordings of oral hygiene (P1I), gingival health (GI), bleeding on probing (BoP), probing depth (PD), clinical attachment level (CAL), and microbial morphotypes from subgingival paper point samples were performed pre-irrigation, and at 1, 2, 4, 6, 8, 10, and 12 weeks post-irrigation. Mean post-irrigation P1I was low, fluctuating between 0.0 and 0.4, without significant differences between experimental groups. Mean pre-irrigation GI approximated 1.4 and reached 0.8 at the exit of study without significant differences between experimental groups. All experimental sites exhibited BoP pre-irrigation. BoP was significantly reduced in TTC50 compared to TTC10, CHX and control sites from week 8 post-irrigation. PDs were reduced for the experimental groups with TTC50 exhibiting the strongest reduction. CALs remained unaltered from pre-irrigation for TTC10, CHX and control sites over the 12-week observation interval, whereas TTC50 sites consistently improved to significantly differ from all other groups at week 10 and 12 post-irrigation. The distribution of bacterial morphotypes was significantly altered towards one of periodontal health for all experimental groups with a profound effect for TTC50 sites. Our results suggest that subgingival irrigation with TTC solutions at high concentrations may have a role in the management of adult periodontitis.

Awareness of periodontal disease--the role of industry

Recently periodontal treatments have been performed intensively in daily clinical work and the definitive approach to periodontal therapy has been established in various types of periodontal diseases. It is no exaggeration to say that this is impossible without the co-operation of the dental industry. Furthermore, industry has also contributed greatly to the improvement of the 'quality of life', concerning masticatory function in the elderly. Both the progression of dental devices and the development of diagnostic methods have been considered to be the primary prerequisite for success in treatment and in the prevention of recurrence of the periodontal diseases. It is necessary that dental devices and medications for treatment should be developed corresponding to the advanced scientific evaluation of periodontal disease. This paper reviews our present knowledge about the role or contribution of industry to periodontology in terms of periodontal health care products, diagnostic kits, and therapeutic drugs.

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.

Biodegradable microparticles for sustained delivery of tetracycline to the periodontal pocket: formulatory and drug release studies

This paper describes the production and characterization of biodegradable microparticles containing tetracycline, designed for periodontal disease therapy. The influence of production parameters on microparticle characteristics and antibiotic release modality was studied. Microparticles were made by using different preparation procedures and different polyesters, namely poly(L-lactide), [L-PLA] poly(DL-lactide), [DL-PLA] and poly(DL-lactide-co-glycolide) 50:50, [DL-PLG]. A double emulsion preparation method together with a concentrated salt solution as external phase gave the best results in terms of tetracycline incorporation efficacy. In vitro release experiments demonstrated that tetracycline is slowly and appropriately released from microparticles. Release kinetics were found to be influenced by the type of polymer utilized for microparticle production. In vitro experiments, simulating in vivo conditions were carried out for up to 30 days. Only DL-PLG microparticles showed significant changes in their morphology, whereas L-PLA and DL-PLA were found almost intact after the same period of time.

Subgingival delivery of therapeutic agents in the treatment of periodontal diseases

This article reviews the current status of controlled local delivery of antibacterial agents in the treatment of periodontitis. The principle of local intrapocket delivery of antibacterial agents and their delivery are discussed. The dosage forms include fibers, film/slabs, and injectable systems, some of which are degradable, while others are not and need to be removed at the termination of the treatment. The antibacterial agents used cover a range of antibiotics as well as antiseptics, and the composition of the delivery systems, their reported use, and the clinical results are summarized. The use of these systems in clinical practice is relatively recent, and therefore their application and integration into the dental office are not yet clearly defined. Clinical applications that have been tested are critically reviewed, and clinical situations in which controlled delivery of antibacterial agents may prove to be clinically useful are suggested for scientific evaluation.

Microbiological response to mechanical treatment in combination with adjunctive therapy. A review of the literature

The recognition of the microbial origin and the specificity of periodontal infections has resulted in the development of several adjunctive therapies (antibiotics and/or antiseptics) to scaling and root planing in the treatment of chronic adult periodontitis. This article aims to review the "additional" effect of a subgingival irrigation with chlorhexidine, or a local or systemic application of tetracycline or metronidazole, performed in combination with a single course of scaling and root planing in patients with chronic adult periodontitis. All treatment modalities are compared with scaling and root planing, based on their impact on: the probing depth (PD); total number of colony forming units per ml (CFU/ml); the proportions and/or the detection-frequency of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia; and/or on the percentages of cocci, spirochetes, motile, and other micro-organisms on dark field microscopy examination. All treatment modalities, including scaling and root planing without additional chemical therapy, resulted in significant reductions in the probing depth and the proportions of periodontopathogens, at least during the first 8 weeks post-therapy. However in comparison to a single course of scaling and root planing, the supplementary effect of adjunctive therapies seems to be limited. In general, only the irrigation with chlorhexidine 2%, the local application of minocycline, and the systemic use of metronidazole (in case of large proportions of spirochetes) or doxycycline (in case of large proportions of A. actinomycetemcomitans) seem to result in a prolonged supplementary effect when compared to scaling and root planing. Therefore, the use of antibiotics on a routine basis, especially in a systemic way, in the treatment of chronic adult periodontitis, can no longer be advocated, considering the increasing danger for the development of microbial resistance.

Full- versus partial-mouth disinfection in the treatment of periodontal infections. A pilot study: long-term microbiological observations

A standard periodontal treatment consists of 4 to 6 scalings and rootplanings at a 1- to 2-week interval, which allows reinfection of a previously disinfected area before completion of the treatment. The present pilot study aims to examine the microbiological long-term effects of a full-mouth disinfection. 10 patients with advanced chronic periodontitis were randomly allocated to a test and control group. The patients from the control group received scaling and rootplaning and oral hygiene instructions at a 2-week interval. The full-mouth disinfection (test group) consisted of a full-mouth scaling and rootplaning in 2 visits within 24 h in combination with: tongue brushing with 1% chlorhexidine gel for 1 min, mouth rinsing with 0.2% chlorhexidine solution for 2 min and subgingival irrigation of all pockets (3x in 10 min) with 1% chlorhexidine gel. The patients of the test group were instructed to rinse 2x daily with 0.2% chlorhexidine. Plaque samples were taken at baseline and after 1, 2, 4 and 8 months. Differential phase-contrast microscopy showed a significantly larger reduction of spirochetes and motile organisms in the test group up to month 2 for the single-rooted and up to month 8 for the multi-rooted teeth. Furthermore, the culture data supported the effectiveness of the new treatment strategy. In both groups, the number of anaerobic CFU decreased 1 log around single- and 0.5 log around multi-rooted teeth. The number of anaerobic CFU remained low in the test group, in contrast to the control group. At 1 month, the test group harboured a significantly (p<0.01) lower proportion of pathogenic organisms, but this difference disappeared with time. Moreover, the test sites showed a significantly higher (p<0.02) increase in the proportion of beneficial micro-organisms up to 4 months. These findings suggest that a full-mouth disinfection leads to a significant microbiological improvement up to 2 months, which could be consolidated, although not significant, for the next 6 months.

2 multi-center trials assessing the clinical efficacy of 5% sanguinarine in a biodegradable drug delivery system

A biodegradable drug delivery system containing 5% sanguinarium (Sa) was compared to vehicle control (VC), scaling and root planing (SRP), and supragingival plaque control (SPC) in the treatment of adult periodontitis in 2 well-controlled clinical trials. Studies were 4-quadrant (split mouth) designs at 2 centers each, having 94 (Study A) and 107 (Study B) patients. All patients had at least 3 pockets between 5 and 9 mm that bled on probing, in each quadrant. Probing pocket depth (PD), clinical attachment level (AL), bleeding on probing (BOP), and plaque index were recorded at baseline, 14, 30, 60, and 90 days. All treatments gave statistically significant reductions from baseline for PD and BOP, and significant gains for AL. For PD reduction, SRP was superior to all test groups at all time points in both studies (p < 0.001). Sa was superior to VC in Study A at 14 and 30 days and to SPC at all time points. For AL gain at 90 days, in both studies, SRP gave gains of 0.42 and 0.78 mm respectively with superiority seen over the SPC group at 90 days (p < 0.001) in study A only, For BOP reduction, in Study A SRP was superior to Sa, VC, and SPC at 60 and 90 days (p < 0.005) and in Study B superiority to Sa and VC was at 90 days and to SPC at 60 days (p < 0.05). Sa was superior to VC for pocket depth in deep pockets only. Sa failed to demonstrate superiority over VC on a consistent basis. Analysis of residual Sa indicates that Sa potency was insufficient to show an advantage beyond clinical effects inherent in treatments with VC and SPC.

Response to intracrevicular controlled delivery of 25% tetracycline from poly(lactide/glycolide) film strips in SPT patients

Controlled local delivery of antibiotics has been shown to reduce periodontopathic micro-organisms with minimal side-effects. Clinical studies in our laboratory have shown that 25% tetracycline HCl delivered from poly(D,L-lactide/glycolide) film strips (25 TTC-PLGA) released therapeutic concentrations of tetracycline for 10 days. The present pilot study compared the intracrevicular delivery of 25% tetracycline HCl incorporated in these biodegradable film strips to scaling and root planing (SRP) in 10 adult periodontitis patients, who in spite of therapy and regular supportive periodontal treatment (SPT), continued to possess 5 bleeding periodontal pockets at least 5 mm deep. Sites were randomly selected to receive the following treatments: (1) 25 TTC-PLGA, (2) control strips without TTC (PLGA), (3) SRP, and (4) untreated control. Film-strip retention was augmented with a suture/cement technique, followed by strip removal after 2 weeks. Clinical parameters and subgingival bacterial morphotypes (darkfield analysis) were evaluated over time (0, 2.4, 8, 12, 26 weeks). Results indicated that, compared to baseline, 25 TTC-PLGA film strips caused significant (p < or = 0.01): (1) probing depth reduction for 26 weeks, (2) a clinical attachment level gain for 12 weeks, (3) lower %s of spirochetes for 4 weeks and motile rods for 8 weeks (p < or = 0.05), and (4) an accompanying increase in cocci for 4 weeks. In the scaled and root planed sites, probing depth was the only finding that demonstrated a significant change from baseline (p < or = 0.01). Controls and PLGA showed isolated reductions in probing depth and % of motile organisms. From these findings, applications of intracrevicular 25 TTC-PLGA, when compared to scaling and root planing, appears to have an enhanced antibacterial effect and a similar clinical effect in SPT patients. The results of this study indicate further investigation of 25 TTC-PLGA film strips should be undertaken using more subjects and sophisticated microbiological and clinical measurements.

Interleukin 4 (IL-4) and IL-6-producing memory T-cells in peripheral blood and gingival tissue in periodontitis patients with high serum antibody titers to Porphyromonas gingivalis

We assessed cytokine production and proliferation of memory T-cells that were isolated from peripheral blood of adult periodontitis patients with high anti-Porphyromonas gingivalis titer. Memory T-cells were stimulated with P. gingivalis lipopolysaccharide, sonicates and formalin-killed whole cells. Interleukin 4(IL-4)- and IL-6-producing cells were stained by immunocytochemistry on peripheral blood smears and compared with cryostat sections of autologous gingival biopsies. Memory T-cells in the peripheral blood of patients rated significantly higher than in healthy subjects (32.3 + or - 7.1 vs 25.3 + or - 3.0%). Stimulation of patient-derived memory T-cells with P. gingivalis whole cells induced higher IL-4 production than in healthy subjects (4.4 + or - 4.1% vs 0.7 + or - 0.6%). Induction of IL-4 producing memory T-cells by P. gingivalis lipopolysaccharide and whole cells was respectively 1.37 and 1.56 times that induced by medium alone. IL-6 production did not differ between the groups. Proliferation of memory T-cells in healthy subjects tended to be more inhibited by P. gingivalis antigens than that in patients. In some patients, induction of IL-4- and IL-6-producing memory T-cells in peripheral blood and in autologous gingival biopsies tended to coincide. Memory T-cells with functional characteristics of Th2 could be a crucial cell population capable of reflecting individual susceptibility to periodontitis.

Pharmacological control of periodontal disease. II. Antimicrobial agents

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

Tetracyclines in the management of periodontal diseases. A review

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

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

The clinical efficacy of minocycline in a subgingival local delivery system was evaluated alone (M) or as an adjunct to scaling and root planing (M + SRP), in comparison to scaling and root planing (SRP) or to no subgingival treatment (NoTx) in adult periodontitis. Fifty-one adult patients with > or = 7 mm periodontal pockets demonstrating the presence by culture of Porphyromonas gingivalis (Pg), Prevotella intermedia (P(i)), or Actinobacillus actinomycetemcomitans (Aa) were randomized into one of the above 4 treatment groups. All sites > or = 5 mm in the most diseased quadrant in each patient received the therapy. Other quadrants were not treated. All patients received standardized oral hygiene instructions at the beginning of the study. At 0, 1, 3 and 6 months following therapy the 7 mm experimental sites were evaluated for selected periodontal pathogens by DNA probe analysis. At these same time points, the plaque index, gingival index, and bleeding on probing were evaluated as well as probing depth and relative clinical attachment level which were assessed by means of an automated probe. Probing depth reduction with M + SRP was significantly greater than all other groups at one month and significantly greater than NoTx and SRP at 3 months. There were no differences in probing depth reduction among groups at 6 months. At 6 months the gain in clinical attachment level was significantly greater for SRP than for either the NoTx or M groups. The prevalence of Pg decreased significantly in the M and M + SRP groups at one month.(ABSTRACT TRUNCATED AT 250 WORDS)

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

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

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

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