Comparison of 3 periodontal local antibiotic therapies in persistent periodontal pockets

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.

Adjunctive local treatments for patients with residual pockets during supportive periodontal care: A systematic review and network meta-analysis

AIM

This systematic review and network meta-analysis aimed to evaluate the efficacy of adjunctive locally delivered antimicrobials, compared to subgingival instrumentation alone or plus a placebo, on changes in probing pocket depth (PPD) and clinical attachment level (CAL), in patients with residual pockets during supportive periodontal care.

MATERIALS AND METHODS

Literature search was performed with electronic databases and by hand until 31 May 2020. Primary outcome was the changes in PPD. The treatment effects between groups were estimated with weighted mean differences (WMD) with 95% confidence intervals (CI) and prediction intervals (PI) by using random-effects network meta-analysis.

RESULTS

Twenty-two studies were included. Significantly greater PPD reduction was achieved in chlorhexidine chip group (WMD: 0.65 mm, 95% CI: 0.21-1.10) and tetracycline fibre group (WMD: 0.64 mm, 95% CI: 0.20-1.08) over 6-month follow-up. Other adjunctive antimicrobial agents achieved non-significant improvements compared to scaling and root planing alone. All differences between adjunctive therapies were statistically non-significant. Similar findings were observed for CAL gain.

CONCLUSION

Adjunctive local antimicrobial agents achieved small additional PPD reduction and CAL gain in residual pockets for a follow-up of up to 6 months. Tetracycline fibre and chlorhexidine chip achieved better results than other antimicrobials.

Comparing the Effect of Combination of 1% Ornidazole and 0.25% Chlorhexidine Gluconate (Ornigreat™) Gel and Aloe vera Gel in the Treatment of Chronic Periodontitis: A Randomized, Single-Blind, Split-Mouth Study

Aim and Objective:

The aim of this study is to compare the efficiency of subgingivally delivered 1% ornidazole and 0.25% chlorhexidine (CHX) gluconate (Ornigreat™ gel) and Aloe vera (AV) gel in the treatment of chronic periodontitis.

Materials and Methods:

Twenty chronic periodontitis patients with pocket depths ranging from 4 to 6 mm bilaterally at least in one site were included in the study. After a thorough nonsurgical periodontal therapy, 1% ornidazole and 0.25% CHX gluconate (Ornigreat™ gel) and AV gel were subgingivally delivered into the pocket sites, and the clinical parameters such as plaque index (PI), gingival index (GI), bleeding index (BI), and clinical attachment level (CAL) were evaluated at baseline and after 4 weeks.

Results:

In both the groups, a reduction in PI, GI, and probing depth readings was evidenced after 4 weeks. A significant improvement was noticed in the BI in the AV group when compared with that of Ornigreat™ group. Taking CAL into consideration, though improvement was there in both the groups, it was not appreciable.

Conclusion:

AV which is an herbal derivative when subgingivally delivered in the pocket site could be an equally effective and affordable substitute for Ornigreat™ gel.

Commercial Local Pharmacotherapeutics and Adjunctive Agents for Nonsurgical Treatment of Periodontitis: A Contemporary Review of Clinical Efficacies and Challenges

Periodontal infections tend to be site-specific, mostly confined to the periodontal pocket. With the surge of antibiotic-resistant bacteria, the trend is shifting towards other therapeutic modalities, especially locally delivered approaches that include other pharmacotherapeutic drugs and medical devices. This narrative review aimed to provide insights into the clinical efficacy of local drug delivery and adjunctive agents used in nonsurgical management of periodontitis. Electronic (PubMed/MEDLINE, CENTRAL, and EMBASE) and bibliographic searches of past systematic reviews were carried out to identify previous publications on the topic. Only relevant literature and randomized controlled trials published in English were selected. In addition, a literature review was developed based on the selected articles. Experimental drugs or agents were excluded. This review highlights the clinically proven and commercially available therapeutic agents related to the management of periodontal disease with comparisons of their clinical efficacies and challenges. A vast array of commercial local pharmacotherapeutic agents had been clinically tested, but the methodologies and clinical results varied within and between each agent used, causing difficulty in drawing conclusions and providing support to the superiority of one agent over another. Considering the benefit-cost ratio with the modest clinical results, the long-term usefulness of these agents remains debatable.

Antibacterial Activity of Nitric Oxide-Releasing Hyperbranched Polyamidoamines

Hyperbranched polyamidoamines (h-PAMAM) were prepared using a one-pot reaction to have similar molecular weight to third generation PAMAM (G3-PAMAM) dendrimers, and then functionalized with N-diazeniumdiolate nitric oxide (NO) donors. A wide range of NO storage capacities (∼1-2.50 μmol mg-1) and NO-release kinetics (t1/2 ∼30-80 min) were achieved by changing the extent of propylene oxide (PO) modification. The therapeutic potential of these materials was evaluated by studying their antibacterial activities and toxicity against common dental pathogens and human gingival fibroblast cells, respectively. Our results indicate that the combination of NO release and PO modification is necessary to yield h-PAMAM materials with efficient bactericidal action without eliciting unwarranted cytotoxicity. Of importance, NO-releasing PO-modified h-PAMAM polymers exhibited comparable biological properties (i.e., antibacterial action and cytotoxicity) to defect-free G3-PAMAM dendrimers, but at a substantially lower synthetic burden.

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.

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.

Anti-biofilm action of nitric oxide-releasing alkyl-modified poly(amidoamine) dendrimers against Streptococcus mutans

The effect of nitric oxide (NO)-releasing dendrimer hydrophobicity on Streptococcus mutans killing and biofilm disruption was examined at pH 7.4 and 6.4, the latter relevant to dental caries. Generation 1 (G1) poly(amidoamine) (PAMAM) dendrimers were modified with alkyl epoxides to generate propyl-, butyl-, hexyl-, octyl-, and dodecyl-functionalized dendrimers. The resulting secondary amines were reacted with NO to form N-diazeniumdiolate NO donor-modified dendrimer scaffolds (total NO ∼1μmol/mg). The bactericidal action of the NO-releasing dendrimers against both planktonic and biofilm-based S. mutans proved greatest with increasing alkyl chain length and at lower pH. Improved bactericidal efficacy at pH 6.4 was attributed to increased scaffold surface charge that enhanced dendrimer-bacteria association and ensuing membrane damage. For shorter alkyl chain (i.e., propyl and butyl) dendrimer modifications, increased antibacterial action at pH 6.4 was due to faster NO-release kinetics from proton-labile N-diazeniumdiolate NO donors. Octyl- and dodecyl-modified PAMAM dendrimers proved most effective for eradicating S. mutans biofilms with NO release mitigating dendrimer scaffold cytotoxicity.

STATEMENT OF SIGNIFICANCE

We report the antibacterial and anti-biofilm efficacy of dual-action nitric oxide (NO)-releasing dendrimers against S. mutans, an etiological agent in dental caries. This work was undertaken to enhance the anti-biofilm action of these scaffolds by employing various alkyl chain modifications. Furthermore, we evaluated the ability of NO to eradicate cariogenic biofilms. We found that at the lower pH associated with dental caries (pH ∼6.4), NO has a more pronounced antibacterial effect for alkyl modifications less capable of biofilm penetration and membrane disruption. Of greatest significance, we introduce dendrimers as a new macromolecular antibacterial agent against the cariogenic bacteria S. mutans.

Comparative evaluation of efficacy of three treatment modalities - tetracycline fibers, scaling and root planing, and combination therapy: A clinical study

Background

Tetracycline is one of the primary antibiotics prescribed for antimicrobial therapy in periodontics. It has a broad spectrum of activity being effective against most bacteria as well as spirochetes. Due to limitations of systemic drug therapy, recent formulations of the drug for local administration in the subgingival area have been introduced, including collagen fibers impregnated with tetracycline.

Aims and Objective

To compare the effectiveness of tetracycline fibers alone or in combination with scaling and root planing (SRP) on clinical parameters in chronic periodontitis patients.

Materials and Methods

A total of twenty patients comprising of both sexes in the age group of 35-60 years with chronic periodontitis were selected. Split-mouth design was used, and three teeth from each patient with periodontal pocket measuring > 5 mm were selected which were treated with different treatment modality. They were randomly divided into site A (SRP), site B (tetracycline fibers only), and site C (combination therapy). Clinical parameters of plaque index (PI), gingival index (GI), pocket probing depth, and clinical attachment level (CAL) were recorded at 0, 30, and 45 days. The data obtained was compiled and put to statistical analysis.

Results

All the three groups showed improvement in PI, GI, probing pocket depth, and CAL. Results of the study showed greater improvements in clinical parameters in Group C compared to Group A and Group B.

Conclusion

The results indicate that the adjunctive use of tetracycline fibers with SRP is a clinically effective and simple nonsurgical treatment method to improve periodontal health.

Kinetic-dependent Killing of Oral Pathogens with Nitric Oxide

Nitric oxide (NO)-releasing silica nanoparticles were synthesized via the co-condensation of tetramethyl orthosilicate with aminosilanes and subsequent conversion of secondary amines to N-diazeniumdiolate NO donors. A series of ~150 nm NO-releasing particles with different NO totals and release kinetics (i.e., half-lives) were achieved by altering both the identity and mol% composition of the aminosilane precursors. Independent of identical 2 h NO-release totals, enhanced antibacterial action was observed against the periodontopathogens Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis with extended NO-release kinetics at pH 7.4. Negligible bactericidal effect was observed against cariogenic Streptococcus mutans at pH 7.4, even when using NO-releasing silica particles with greater NO-release totals. However, antibacterial activity was observed against S. mutans at lower pH (6.4). This result was attributed to more rapid proton-initiated decomposition of the N-diazeniumdiolate NO donors and greater NO-release payloads. The data suggest a differential sensitivity to NO between cariogenic and periodontopathogenic bacteria with implications for the future development of NO-releasing oral care therapeutics.

Alpha-2-Macroglobulin Levels in Gingival Crevicular Fluid Pre- and Post-scaling and Root Planing with Adjunctive Tetracycline Fibers in Chronic Periodontitis: A Randomized Controlled Trial

BACKGROUND

This split-mouth clinical study aimed to investigate levels of alpha-2-macroglobulin (a2M) in gingival crevicular fluid (GCF) of chronic periodontitis patients pre- and post-scaling and root planing (SRP) with or without adjunctive use of tetracycline fibers.

MATERIALS AND METHODS

In 30 patients of chronic periodontitis, samples of GCF were collected from the gingival sulcus before SRP. Recording of clinical parameters was conducted. This was followed by local drug delivery (LDD) of tetracycline fibers in test sites. In control sites, no LDD was done. Second samples of GCF were taken 90 days after treatment. Samples of crevicular fluid were analyzed to determine the levels of a2m.

RESULTS

A gain of clinical attachment (CAL) of 3.30 mm for SRP and LDD and for SRP alone was 1.62 mm (p < 0.001). The pocket probing depth was significantly decreased by 2.43 mm for SRP and LDD and for SRP alone was 1.61 mm (p < 0.001) after 90 days. Alpha-2-macroglobulin was significantly reduced in GCF by SRP and SRP and LDD after 90 days (p < 0.001).

CONCLUSION

Clinical and biochemical variables showed a more favorable outcome when SRP was combined with LDD of tetracycline fibers in management of patients suffering from chronic periodontitis.

Antibacterial efficacy of exogenous nitric oxide on periodontal pathogens

Current treatments for periodontitis (e.g., scaling/root planing and chlorhexidine) have limited efficacy since they fail to suppress microbial biofilms satisfactorily over time, and the use of adjunctive antimicrobials can promote the emergence of antibiotic-resistant organisms. Herein, we report the novel application of nitric oxide (NO)-releasing scaffolds (i.e., dendrimers and silica particles) as anti-periodontopathogenic agents. The effectiveness of macromolecular NO release was demonstrated by a 3-log reduction in periodontopathogenic Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis viability. In contrast, Streptococcus mutans and Streptococcus sanguinis, caries-associated organisms, were substantially less sensitive to NO treatment. Both dendrimer- and silica-based NO release exhibited substantially less toxicity to human gingival fibroblasts at concentrations necessary to eradicate periodontopathogens than did clinical concentrations of chlorhexidine. These results suggest the potential utility of macromolecular NO-release scaffolds as a novel platform for the development of periodontal disease therapeutics.

Diagnosis and anti-infective therapy of periodontitis

Periodontal diseases (gingivitis and periodontitis) are chronic bacterial infections with a remarkably high prevalence and morbidity. Periodontitis, in contrast to gingivitis, is not reversible, is associated with certain bacterial species and affects all of the soft tissue and bone that support teeth. Among the periodontal pathogens, species, such as Aggregatibacter (Actinobacillus) actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, and several forms of uncultivable spirochetes play the major role in the pathogenesis. In severe chronic, recurrent and especially aggressive forms of periodontitis, diagnosis of the species involved and, whenever possible, an optimized evidence-based antimicrobial treatment is indicated. In order to monitor alarming bacterial changes in the periodontal pocket, several techniques, namely microscopy, culture, immunoassays, enzyme tests and DNA-based techniques, have been established and the methods are described in the first part of this review. In the second part, the selection and use of locally delivered (topical) and systemic antibiotics used adjunctively in periodontal therapy are discussed.

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.

Antimicrobial photodynamic therapy using a diode laser with a potential new photosensitizer, indocyanine green-loaded nanospheres, may be effective for the clearance of Porphyromonas gingivalis

BACKGROUND

Antimicrobial photodynamic therapy (aPDT) is a new treatment method for the removal of infectious pathogens using a photosensitizer and light of a specific wavelength, e.g., toluidine blue with a wavelength of about 600 nm. We explored a new photosensitizer and focused on indocyanine green (ICG), which has high absorption at a wavelength of 800-805 nm. We investigated the bactericidal effect of PDT on Porphyromonas gingivalis using a new photosensitizer, ICG-loaded nanospheres with an 805 nm wavelength low-level diode laser irradiation.

METHODS

We designed ICG-loaded nanospheres coated with chitosan (ICG-Nano/c) as a photosensitizer. A solution containing Porphyromonas gingivalis (10(8)  CFU/mL) with or without ICG-Nano/c (or ICG) was prepared and irradiated with a diode laser or without laser irradiation as a negative control. The irradiation settings were 0.5 W with a duty ratio of 10%, for 3-100 ms in repeated pulse (RPT) or continuous wave mode. CFU were counted after 7 d of anaerobic culture.

RESULTS

We observed that ICG-Nano/c could adhere to the surface of P. gingivalis. When ICG-Nano/c was used for aPDT, irradiation with RPT 100 ms mode gave the lowest increase in temperature. Laser irradiation with ICG-Nano/c significantly reduced the number of P. gingivalis (i.e., approximately 2-log10 bacterial killing). The greatest bactericidal effect was found in the RPT 100 ms group. However, laser irradiation (RPT 100 ms) with ICG, as well as without photosensitizer, had no effect on the number of bacteria.

CONCLUSIONS

Within the limits of this study, ICG-Nano/c with low-level diode laser (0.5 W; 805 nm) irradiation showed an aPDT-like effect, which might be useful for a potential photodynamic periodontal therapy.

Therapeutic strategies in the treatment of periodontitis

Periodontitis is a chronic inflammatory process which affects the tooth - supporting structures of the teeth. The disease is initiated by subgingival periopathogenic bacteria in susceptible periodontal sites. The host immune response towards periodontal pathogens helps to sustain periodontal disease and eventual alveolar bone loss. Although scaling and root planing is the standard treatment modality for periodontitis, it suffers from several drawbacks such as the inability to reach the base of deep pockets and doesn’t arrest migration of periodontal pathogens from other sites in the oral cavity. In order to overcome the limitations of scaling and root planning, adjunctive chemotherapeutics and host modulatory agents to the treatment are used. These therapeutic agents show substantial beneficial effects when compared to scaling and root planning alone. This review will cover an update on chemotherapeutic and past and future host immune modulatory agents used adjunctively to treat and manage periodontal diseases.

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.

Single use of tetracycline with and without diclofenac sodium as local drug delivery in pocket therapy: a clinico-microbiological study

AIM

  Local drug delivery is a non-surgical method in the treatment of periodontitis. Different chemotherapeutic agents are used for local drug delivery; one such agent is tetracycline, a broad-spectrum antibiotic. Recent studies have also shown that the use of non-steroidal anti-inflammatory drugs reduces pro-inflammatory cytokines and acts as host modulator. Thus, an attempt was made to compare and evaluate the efficacy of tetracycline alone and in combination with diclofenac sodium as a local drug delivery.

METHODS

  A total of 36 sites with chronic periodontitis were divided into three groups with 12 sites each (i.e. group A, antibiotics alone; group B, antibiotics in combination with non-steroidal anti-inflammatory drugs; and group C, control group). For all the groups, the following parameters (plaque index, papillary bleeding index, probing pocket depth, and microbial analysis) were assessed and statistically analyzed.

RESULTS

  The antibiotic and non-steroidal anti-inflammatory drug combination group showed a statistically-significant improvement in clinical parameters and a shift in microbial flora when compared to the group with antibiotics alone. However, the control group failed to show any statistically-significant improvement.

CONCLUSION

  Antibiotics in combination with non-steroidal anti-inflammatory drugs are more efficient than using antibiotics alone as local drug delivery for the treatment of periodontal pockets.

The effect of locally delivered doxycycline as an adjunctive therapy to scaling and root planing in smokers

BACKGROUND

Locally delivered doxycycline is found to be effective in managing periodontitis as an adjunct to scaling and root planing.

AIM

To evaluate the effect of locally delivered doxycycline (10%) with scaling and root planing in the periodontal treatment of smokers and to compare it with scaling and root planing alone.

METHODS

Twelve smokers with chronic periodontitis and a pocket depth (⩾5 mm) on posterior teeth that bleed on probing were selected. Patients were randomly assigned to scaling and root planing (SRP) or scaling and root planing followed by local application of doxycycline (SRP-D). Plaque, bleeding on probing, gingival recession, clinical attachment level (CAL), and probing depth (PD) were recorded at the baseline, 6 and 12 weeks.

RESULTS

Both groups showed a significant reduction in Plaque, Bleeding on Probing and pocket depth at 6th and 12th week from the baseline. A statistically significant gain of attachment was observed in both groups after treatment. Even though the doxycycline group showed slightly higher attachment gain it was not statistically significant compared to the control group.

CONCLUSION

The observations of the study reveal that the additional benefit of topical application of doxycycline as an adjunct to scaling and root planing in smokers is not convincing. However, further clinical studies may be necessary to substantiate the present observations.

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.

Topical use of a metronidazole gel in the treatment of sites with symptoms of recurring chronic inflammation

BACKGROUND

Bacterial plaque accumulation at the dentogingival junction and in periodontal pockets is the major etiologic factor in all manifestations of periodontal disease. The aim of this study was to evaluate whether a locally delivered 25% metronidazole gel after scaling and root planing (SRP) would enhance the treatment outcome over SRP alone in periodontal pockets with symptoms of recurring chronic inflammation.

METHODS

Twenty-one maintenance-care patients, 10 men and 11 women, having at least one pair of contralateral anatomically matching proximal tooth surfaces showing probing depth > or = 5 mm and bleeding on probing (BOP), were included in the study. The sites were randomized to be treated with SRP plus 25% metronidazole gel (test sites) or with SRP alone (control sites) in a split-mouth design. Clinical evaluations were performed immediately pretreatment (baseline) and at 3 and 6 months post-treatment.

RESULTS

Both treatments yielded a statistically significant (P = 0.001) reduction in probing depth (1.9 and 1.8 mm), gain of attachment level (1.6 and 1.0 mm), and reduction of BOP (38.1% and 33.3%) for test and control sites, respectively, at 6 months. There was no statistically significant difference between the treatments for any of the clinical parameters.

CONCLUSION

This study indicates that a locally applied 25% metronidazole gel does not improve the treatment outcome over SRP alone in sites with recurring chronic inflammation in maintenance-care patients.

Unexpected effect of a Bacteroides conjugative transposon, CTnDOT, on chromosomal gene expression in its bacterial host

Foreign DNA elements such as plasmids and conjugative transposons are constantly entering new bacterial hosts. A possible outcome of such events that has not been considered previously is that regulatory genes carried on some of them might affect the expression of chromosomal genes of the new host. To assess this possibility, we investigated the effect of the Bacteroides conjugative transposon CTnDOT on expression of chromosomal genes in Bacteroides thetaiotaomicron 5482 (BT4001). Most of the upregulated genes were genes of unknown function, but a number of them were associated with a region of the chromosome that contained a putative conjugative transposon, which had been tentatively designated as CTn4-bt. Upregulation of CTn4-bt genes and other chromosomal genes affected by CTnDOT was controlled by two regulatory genes on CTnDOT, rteA and rteB, which encode a two-component regulatory system. Transfer of CTn4-bt was also mediated by rteA and rteB. Three other putative CTns, CTn1-bt, CTn2-bt and CTn3-bt, were mobilized by CTnERL, a CTn closely related to CTnDOT, but genes from CTnERL other than rteA and rteB were also required. Unexpectedly, homologous recombination was required for CTn1-bt, CTn2-bt, CTn3-bt and CTn4-bt to integrate in the recipient. Our results show that regulatory genes on an incoming mobile element can have multiple effects on its new host, including the activation of previously non-transmissible elements.

Clinical Evaluation of the Use of Locally Delivered Chlorhexidine in Periodontal Maintenance Therapy

BACKGROUND

The objective of this study was to evaluate clinically the effectiveness of a chlorhexidine gluconate chip in sites still showing signs of disease during periodontal maintenance therapy.

METHODS

Forty-two maintenance non-smoking patients (previously treated with non-surgical scaling and root planing [SRP]), presenting at least one probing depth (PD) of 5 to 8 mm, and bleeding on probing (BOP) at single-rooted teeth were assigned randomly to two groups: treated with a chlorhexidine gluconate chip (CHIP group) and treated with SRP (SRP group). Patients were assessed for plaque index, gingival index, BOP, PD, clinical attachment level (CAL), and gingival recession at baseline, 6 weeks, and 3 and 6 months.

RESULTS

Both treatments resulted in improvements in all parameters evaluated. After 6 months, a reduction in PD of 2.64 +/- 0.02 mm and 2.12 +/- 0.02 mm was observed for CHIP and SRP groups, respectively (P >0.05). The observed gain in CAL was 2.19 +/- 0.87 mm and 2.07 +/- 1.53 mm for CHIP and SRP groups, respectively (P >0.05). In deep pockets, PD reduction was 3.60 +/- 0.70 mm for CHIP group and 2.83 +/- 0.62 mm for SRP group (P = 0.01).

CONCLUSIONS

Both treatments were equally effective in periodontal health reestablishment in inflamed single-root sites of maintenance patients. However, for deep pockets, the chlorhexidine gluconate chip was more effective than SRP in reducing PD.

The effect of topical doxycycline usage on gingival crevicular fluid MMP-8 levels of chronic and aggressive periodontitis patients: a pilot study

The aim of this study was to evaluate the efficacy of topical subgingival application of doxycycline hyclate (DH) gel adjunctive to non-surgical periodontal therapy on gingival crevicular fluid (GCF) matrix metalloproteinase (MMP)-8 levels in chronic and aggressive periodontitis patients. Forty teeth of 10 chronic periodontitis patients and 32 teeth of eight aggressive periodontitis patients were screened for 6 months. Scaling and root planing (SRP) was applied to the control sites and DH gel adjunctive to SRP was applied to the test sites of each patient simultaneously. GCF MMP-8 levels were analysed at baseline, 7 days; and at 1, 3 and 6 months by Sandwich Elisa Method. At 1, 3 and 6 months, probing depth (P < 0.0051) and plaque scores and bleeding on probing values (P = 0.000) significantly decreased in each group when compared with the baseline, but there was no statistically significant difference between the test and control sites. GCF MMP-8 levels reduced presenting statistically significant differences on 7 days, 1, 3 and 6 months in four of the groups (P < 0.05); however, intergroup differences were not statistically significant. Developing functional and immunological-based chair-side MMP tests might serve as useful adjunctive diagnostic tools when monitoring the effects of DH gel application.

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.

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.

Locally Delivered Doxycycline as an Adjunctive Therapy to Scaling and Root Planing in the Treatment of Smokers: A Clinical Study

BACKGROUND

The aim of this clinical study was to evaluate the association of locally delivered doxycycline (10%) with scaling and root planing in the periodontal treatment of smokers.

METHODS

Forty-three patients with chronic periodontitis and a minimum of four pockets (> or = 5 mm) on anterior teeth that bled on probing were selected. Patients were randomly assigned to scaling and root planing (SRP) or scaling and root planing followed by local application of doxycycline (SRP-D). Plaque, bleeding on probing, gingival recession, relative attachment level (RAL), and probing depth (PD) were recorded at baseline, 45 days, and 3 and 6 months. Differences between baseline and each period were considered for analysis.

RESULTS

At 6 months, no difference was found between groups regarding plaque, bleeding reduction, gingival recession or PD (P > 0.05). However, RAL gain was greater for SRP-D (1.63 +/- 0.93 mm) than for SRP (1.04 +/- 0.71 mm) (P = 0.025). In addition, deep pockets (> or = 7 mm) showed a significant reduction (3.78 +/- 1.41 versus 2.60 +/- 1.28 mm, P = 0.039) and RAL gain (2.54 +/- 1.27 mm versus 1.29 +/- 0.95 mm, P = 0.01) when doxycycline was applied. The proportion of sites showing RAL gain of 1 to 2 mm was 36.8% versus 21.7% for SRP-D and SRP, respectively (P = 0.01).

CONCLUSION

The use of locally delivered doxycycline may constitute an important adjunct for the treatment of severe periodontal disease in smokers.

Topical and systemic antibiotics in the management of periodontal diseases

Both systemic and topical antibiotics are increasingly used in the management of periodontal infections. Whilst these drugs are used mostly on an empirical basis, some contend that rational use of antibiotics should be the norm due to their wide abuse and consequential global emergence of antibiotic resistance organisms. Here we review the rationale and principles of antimicrobial therapy, treatment goals, drug delivery routes and various antibiotics that are used in the management of periodontal diseases. The pros and cons of systemic and local antibiotic therapy are described together with practical guidelines for their delivery. The available data indicate, in general, that mechanical periodontal treatment alone is adequate to ameliorate or resolve the clinical condition in most cases, but adjunctive antimicrobial agents, delivered either locally or systemically, can enhance the effect of therapy in specific situations. This is particularly true for aggressive (early onset) periodontitis, in patients with generalised systemic disease that may affect host resistance and in case of poor response to conventional mechanical therapy. Locally delivered antibiotics together with mechanical debridement are indicated for non-responding sites of focal infection or in localised recurrent disease. After resolution of the periodontal infection, the patient should be placed on an individually tailored maintenance care programme. Optimal plaque control by the patient is of paramount importance for a favourable clinical and microbiological response to any form of periodontal therapy.

Meta-analysis of the effect of scaling and root planing, surgical treatment and antibiotic therapies on periodontal probing depth and attachment loss

OBJECTIVE

This paper reports a meta-analysis of studies that have investigated the effect of scaling and root planing on periodontal probing depth and attachment loss.

MATERIAL AND METHODS

The criteria used for inclusion of studies were as follows: root planing and scaling alone was one of the primary treatment arms; patients or quadrants of each patient were randomly assigned to study groups; 80% of patients enrolled were included in first year follow-up examinations; periodontal probing depth and attachment loss were reported in mm; the sample size of each study and substudy was reported. Sample size was used to weight the relative contribution of each study since standard errors were not reported by many studies and sample size is highly correlated with standard error and therefore statistically able to explain a substantial portion of the standard error on studies that use similar measures.

RESULTS

The meta-analysis results show that periodontal probing depth and gain of attachment level do not improve significantly following root planing and scaling for patients with shallow initial periodontal probing depths. However, there was about a 1-mm reduction for medium initial periodontal probing depths and a 2-mm reduction for deep initial periodontal probing depths. Similarly, there was about a 0.50-mm gain in attachment for medium initial periodontal probing depth measurements and slightly more than a l-mm gain in attachment for deep initial periodontal probing depth measurements. Surgical therapy for patients with deep initial probing depths showed better results than scaling and root planing in reducing probing depths. When patients were followed up over 3 years or more, these differences were reduced to less than 0.4 mm. Antibiotic therapy showed similar results to scaling and root planing. However, a consistent improvement in periodontal probing depth and gain of attachment is demonstrated when local antibiotic therapy is combined with root planing and scaling.

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.

Local antimicrobial therapy after initial periodontal treatment

AIM

The aim of this single-blind, randomized, parallel-designed clinical trial (RCT) was to evaluate the clinical and microbiological effects of three sustained-release biodegradable polymers delivered into periodontal pockets following initial periodontal therapy.

METHODS

Forty-seven patients (28 females and 19 males) with a mean age of 51 years (range 29-71) underwent a periodontal examination at baseline (i.e. Week 0) and after 18 weeks. This included the assessment of the Plaque Index (PlI), Bleeding on Probing (BOP), Pocket Probing Depths (PPD) and Probing Attachment Levels (PAL) at six sites per tooth. Two to 4 months prior to baseline, all subjects had received initial periodontal therapy including motivation, instruction in oral hygiene practices and full-mouth scaling and root planing. At the treatment appointment (i.e. Week 2), the patients were randomly assigned to receive either Atridox trade mark, Elyzol Dental Gel or PerioChip at all residual periodontal pockets with a probing depth >/= 5 mm and concomitant BOP. In accordance with the manufacturer's recommendations, Elyzol Dental Gel was applied for a second time 7 days later. In addition to the clinical evaluation, subgingival microbiological samples were collected prior to treatment (i.e. Week 2) and at Weeks 4 and 18. Analysis of variance/covariance was used to evaluate changes from baseline to Week 18 for the clinical parameters.

RESULTS

Between the baseline and 18-week examinations, subjects treated with Atridox showed a significantly greater gain in mean PAL of 0.33 mm +/- 0.09 (SD) than subjects treated with Elyzol Dental Gel [0.03 mm +/- 0.09 (SD)](p = 0.03). However, the gain in PAL of 0.16 mm +/- 0.10 (SD) found after PerioChip application did not differ significantly from that obtained following the application of Atridox(p = 0.27). Of the sites treated with Atridox, 42% gained >/= 1 mm PAL and 9% >/= 2 mm PAL as opposed to the sites treated with Elyzol Dental Gel, in which 34% gained >/= 1 mm PAL and 8% gained >/= 2 mm PAL. Of the sites treated with PerioChip, 36% gained >/= 1 mm and 6% gained >/= 2 mm PAL following a completed initial periodontal therapy.

CONCLUSIONS

The application of the three biodegradable sustained release devices tested following initial periodontal therapy resulted in a statistically significant gain in mean PAL for AtridoxTM and a significant reduction in PPD for all three devices during the study period. Furthermore, when sites treated with Atridox were compared with sites treated with Elyzol, a significant difference in mean PAL gain (0.3 mm) was observed.

Nonsurgical periodontal therapy

Regular home care by the patient in addition to professional removal of subgingival plaque is generally very effective in controlling most inflammatory periodontal diseases. When disease does recur, despite frequent recall, it can usually be attributed to lack of sufficient supragingival and subgingival plaque control or to other risk factors that influence host response, such as diabetes or smoking. Causative factors contributing to recurrent disease include deep inaccessible pockets, overhangs, poor crown margins and plaque-retentive calculus. In most cases, simply performing a thorough periodontal debridement under local anesthesia will stop disease progression and result in improvement in the clinical signs and symptoms of active disease. If however, clinical signs of disease activity persist following thorough mechanical therapy, such as increased pocket depths, loss of attachment and bleeding on probing, other pharmacotherapeutic therapies should be considered. Augmenting scaling and root planing or maintenance visits with adjunctive chemotherapeutic agents for controlling plaque and gingivitis could be as simple as placing the patient on an antimicrobial mouthrinse and/or toothpaste with agents such as fluorides, chlorhexidine or triclosan, to name a few. Since supragingival plaque reappears within hours or days after its removal, it is important that patients have access to effective alternative chemotherapeutic products that could help them achieve adequate supragingival plaque control. Recent studies, for example, have documented the positive effect of triclosan toothpaste on the long-term maintenance of both gingivitis and periodontitis patients. Daily irrigation with a powered irrigation device, with or without an antimicrobial agent, is also useful for decreasing the inflammation associated with gingivitis and periodontitis. Clinically significant changes in probing depths and attachment levels are not usually expected with irrigation alone. Recent reports, however, would indicate that, when daily irrigation with water was added to a regular oral hygiene home regimen, a significant reduction in probing depth, bleeding on probing and Gingival Index was observed. A significant reduction in cytokine levels (interleukin-1beta and prostaglandin E2, which are associated with destructive changes in inflamed tissues and bone resorption also occurs. If patient-applied antimicrobial therapy is insufficient in preventing, arresting, or reversing the disease progression, then professionally applied antimicrobial agents should be considered including sustained local drug delivery products. Other, more broadly based pharmacotherapeutic agents may be indicated for multiple failing sites. Such agents would include systemic antibiotics or host modulating drugs used in conjunction with periodontal debridement. More aggressive types of juvenile periodontitis or severe rapidly advancing adult periodontitis usually require a combination of surgical intervention in conjunction with systemic antibiotics and generally are not controlled with nonsurgical anti-infective therapy alone. It should be noted, however, that, to date, no home care products or devices currently available can completely control or eliminate the pathogenic plaques associated with periodontal diseases for extended periods of time. Daily home care and frequent recall are still paramount for long-term success. Nonsurgical therapy remains the cornerstone of periodontal treatment. Attention to detail, patient compliance and proper selection of adjunctive antimicrobial agents for sustained plaque control are important elements in achieving successful long-term results. Frequent re-evaluation and careful monitoring allows the practitioner the opportunity to intervene early in the disease state, to reverse or arrest the progression of periodontal disease with meticulous nonsurgical anti-infective therapy.

Non-surgical periodontal therapy with adjunctive topical doxycycline: a double-blind randomized controlled multicenter study

AIM

Evaluation of the clinical effect of topical application of doxycycline adjunctive to non-surgical periodontal therapy.

METHODS

A total of 111 patients suffering from untreated or recurrent moderate to severe periodontitis at 3 different centers (Heidelberg, Frankfurt, Nijmegen) were treated in this double-blind split-mouth study. In each patient, 3 different treatment modalities were assigned randomly to 3 test teeth: scaling and root planing alone (SRP), SRP with subgingival vehicle control (VEH), and SRP with subgingival application of a newly developed biodegradable 15% doxycycline gel (DOXI). At baseline, clinical parameters were measured at all single rooted teeth using a reference splint: PlI, PPD, relative attachment level (RAL-V), GI. 3 strata were generated according to baseline PPD: (i) 5-6 mm, (ii) 7-8 mm, (iii) > or =9 mm. Not more than 50% active smokers were allowed to each stratum. 3 and 6 months after therapy re-examination was performed by examiners blinded to baseline data and test sites. The statistical comparison of RAL-V gain and PPD reduction between the treatments was based on a repeated measures ANOVA with correction according to Huynh & Feldt. The comparison of SRP versus DOXI was considered as the main study question.

RESULTS

110 patients finished the 3 months and 108 the 6 months examination. The study did not show adverse effects of VEH or DOXI except for one singular inflammation that occurred 2 months after application of the doxycycline gel. DOXI provided statistically significantly more favorable PPD reduction (SRP: -2.4+/-1.4 mm, VEH: -2.7+/-1.6 mm, DOXI: -3.1+/-1.2 mm; SRP versus DOXI p=0.0001, VEH versus DOXI p=0.0066) and RAL-V gain (SRP: 1.6+/-1.9 mm, VEH: 1.6+/-2.2 mm, DOXI: 2.0+/-1.7 mm; SRP versus DOXI p=0.027, VEH versus DOXI p=0.038) than SRP and VEH after 6 months.

CONCLUSIONS

Adjunctive topical subgingival application of a biodegradable 15% doxycycline gel was safe and provided more favorable RAL-V gain and PPD reduction than SRP alone and VEH. Thus, by use of topical doxycycline the threshold for surgical periodontal therapy might be moved toward deeper pockets.

Opportunities and obstacles in veterinary dental drug delivery

Dentistry is a relatively new field in veterinary medicine, despite the fact that dental disease is common in dogs and cats. Obstacles to the development of dental treatments in animals include the diversity of the dentition among the species, the difficulty in administration of oral treatments, the different presentations of oral disease, and the cost of regulatory approval for each species. Mechanical removal of plaque and calculus has been the mainstay of periodontal disease treatment in animals and humans. New adjunctive therapies, as well as new applications for older drugs, are being introduced for periodontal therapy.

Local versus systemic adjunctive antibiotic therapy in 28 patients with generalized aggressive periodontitis

BACKGROUND

Although the use of systemic antibiotics has been studied in patients with generalized aggressive periodontitis (formerly rapidly progressive periodontitis), the use of adjunctive tetracycline fibers in these patients has not been reported. The purpose of the present study was to compare the clinical response of local versus systemic antibiotic treatment as adjuncts to scaling and root planing in patients with GAgP.

METHODS

After initial therapy and full-mouth scaling and root planing (SRP), 30 patients were randomly assigned to 1 of 2 antibiotic treatment groups. Probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) were recorded with an automated probe prior to SRP at baseline (BL) and 15, 30, 41, and 54 weeks later. Three months after SRP, the patients were treated with amoxicillin/clavulanic acid (500 mg tid; SRP + AUG group) or with local tetracycline fiber in pockets with PD > or =5 mm (SRP + TCF group).

RESULTS

In both treatment groups, PD decreased significantly from BL to week 54 (6.2+/-1.5 mm to 4.7+/-1.4 mm for SRP + TCF and 6.5+/-1.4 mm to 4.2+/-0.6 mm for SRP + AUG). However, there was no statistically significant difference between the 2 groups in pocket reduction. Similarly, in both treatment groups, there were small but significant gains in CAL from BL to week 54 (12.0+/-1.8 mm to 11.3+/-1.8 mm for SRP + TCF and 12.3+/-1.5 mm to 11.2+/-1.2 mm for SRP + AUG). The difference in CAL gain between the 2 groups was not statistically significant. At the final examination, both groups showed significant PD reduction and CAL gain (P <0.001) compared to BL. The frequency and percentage of bleeding sites decreased significantly in both groups. At week 54, this decrease was significantly greater in the SRP + AUG group (31.67% for SRP + TCF versus 3.85% for SRP + AUG).

CONCLUSIONS

These results indicate that the local delivery of tetracycline by a fiber or the systemic administration of amoxicillin/clavulanic acid given 3 months after scaling and root planing produced similar clinical outcomes over the 9-month observation period.

Optimization of a novel bioerodible device based on auto-catalyzed poly(ortho esters) for controlled delivery of tetracycline to periodontal pocket

Local delivery of antimicrobial agents in inflamed periodontal pocket has been shown to be effective in reducing periodontopathic microorganisms. This research focuses on developing and characterizing bioerodible formulations based on auto-catalyzed poly(ortho esters) (POExLAy) for modulated release of tetracycline over 2 weeks. POExLAy are a new versatile family of POE-containing lactoyl lactyl dimers in the polymer backbone. By modifying the proportion of lactic acid in the polymer, viscous or solid materials having different degradation rate can be produced. The formulations can be either injected or placed as a solid device directly into the periodontal pocket. Tetracycline-free base incorporated into these materials was released within 10-14 days depending on polymer structure. Increase in lactic acid content in the polymer tended to increase the drug release rate and to reduce the initial lag time. Tetracycline release from such bioerodible delivery system occurs predominantly by surface erosion of the polymeric matrix, leading to kinetics which can be zero order. This periodontal drug delivery system is designed to be used as an adjunct in the treatment of periodontal diseases. Clinical studies are currently in progress.

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.

Microbiological response of localized sites with recurrent periodontitis in maintenance patients treated with tetracycline fibers

BACKGROUND

Whether adjunctive tetracycline fibers can provide an additive effect to scaling and root planing in treating non-responsive sites in maintenance subjects is still controversial. Recolonization of the bacteria from untreated sites or from the extracrevicular region may explain the insignificant response to local therapy. The purpose of the present study was to evaluate the microbiological response of sites treated with tetracycline fibers combined with scaling and root planing.

METHODS

The study was conducted in a split-mouth design. Thirty patients on maintenance therapy having at least 2 non-adjacent sites in separate quadrants with probing depths between 4 to 8 mm with bleeding on probing, or aspartate aminotransferase enzyme levels > 800 microIU in the gingival crevicular fluid, were treated with scaling and root planing plus tetracycline fibers or with scaling and root planing only. Subgingival plaque samples were collected at baseline, and 1, 3, and 6 months following treatment. A. actino-mycetemcomitans, C. rectus, B. forsythus, E. corrodens, F. nucleatum, P. gingivalis, and P. intermedia were detected by culture, immunofluorescence, or PCR technique.

RESULTS

There was a reduction of total bacterial cell count, as well as of certain periodontal pathogens, following treatment. The prevalence of A. actinomycetemcomitans, B. forsythus, and P. gingivalis and the mean proportions of C. rectus, P. intermedia, F. nucleatum, and P. gingivalis decreased after therapy, but there was no statistically significant difference between the 2 treatment groups with respect to bacterial proportions or the number of positive sites. Besides, the pathogens could not be eliminated from the periodontal pocket, and recolonization of the pocket was noted at 3 months post-treatment.

CONCLUSIONS

Bacteria located within the cheek, tongue mucosa, saliva, or untreated sites may contribute to reinfection of the pockets and explain the insignificant response to local tetracycline therapy.

A six-month comparison of three periodontal local antimicrobial therapies in persistent periodontal pockets

BACKGROUND

Currently, several local antimicrobial delivery systems are available to periodontists. The aim of this 6-month follow-up parallel study was to evaluate the efficacy of three commercially available local delivery systems as adjuncts to scaling and root planing in the treatment of sites with persistent periodontal lesions.

METHODS

Seventy-nine patients with 4 pockets > or = 5 mm and bleeding on probing and/or suppuration were randomized into 4 treatment groups which included: scaling and root planing alone (S) (20 patients), or in conjunction with the application of 25% tetracycline fibers (S+Tet) (19 patients), or 2% minocycline gel (S+Min) (21 patients), or 25% metronidazole gel (S+Met) (19 patients). Clinical measurements were taken at baseline, 6 weeks, 3 months, and 6 months after antimicrobial application. Treatments were applied using the distributors' recommended protocols.

RESULTS

All 4 therapies resulted in significant improvements from baseline in probing depth, attachment level, bleeding on probing, and the Modified Gingival Index (MGI) scores. The improvements in clinical parameters were greater in all 3 adjunctive treatment groups than scaling and root planing alone. The mean probing depth reductions at 6 months were: scaling + tetracycline = 1.38 mm; scaling + metronidazole = 0.93 mm; scaling + minocycline = 1.10 mm; and scaling alone = 0.71 mm. The probing depth reduction at all time points was significantly greater in the scaling plus tetracycline fiber group than the scaling and root planing alone group (P<0.01). There was also a significant improvement for scaling plus tetracycline fiber application over scaling and metronidazole at both 6 weeks and 3 months, although this did not remain significant at the 6-month visit. While the frequency of sites with suppuration was markedly reduced following all antimicrobial treatments, the most effective reductions were seen in the scaling plus tetracycline fiber group, followed by the minocycline group.

CONCLUSIONS

Although all 3 locally applied antimicrobial systems seem to offer some benefit over scaling and root planing alone, a treatment regimen of scaling and root planing plus tetracycline fiber placement gave the greatest reduction in probing depth over the 6 months after treatment.

Local delivery of tetracycline: from concept to clinical application

This manuscript reviews the development over the last 20 years of the evidence supporting the clinical application of a controlled delivery device for the treatment of human periodontitis. The device is a monolithic ethylene vinyl-acetate fibre loaded with 25% w/w tetracycline HCI (tetracycline fibre). It releases tetracycline at a steady state rate of 2 microg/cm x h and results in the maintenance of essentially constant, highly-effective concentrations of tetracycline at the site of action. A series of controlled, randomised, single-blind, phase-III clinical trials including a total of 463 patients has indicated that: (1) tetracycline fibres result in significantly better outcomes than the scaling and root planing positive control; (2) combination of tetracycline fibres with subgingival mechanical debridement results in significant improvement over debridement alone. Evidence from these studies has led to approval of this treatment modality by the US Food and Drug Administration and by the European Union Regulatory Bodies. A clinical usage study involving 2711 subjects treated by 68 clinicians in Europe and North America indicated that the magnitude of the observed clinical outcomes is clinically relevant and that adverse events were rarely observed. A variety of clinical investigations aimed at the optimal incorporation of tetracycline fibres in a treatment strategy provide guidance in case selection. Cost of therapy and concerns of unnecessary usage of antibiotics should be considered. It is nonetheless concluded that combination of tetracycline fibres with mechanical debridement represents a documented treatment alternative, the application of which may offer clinical benefits to many patients.

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.

Adjunctive use of a subgingival controlled-release chlorhexidine chip reduces probing depth and improves attachment level compared with scaling and root planing alone

The present studies evaluated the efficacy of a controlled-release biodegradable chlorhexidine (CHX) (2.5 mg) chip when used as an adjunct to scaling and root planing on reducing probing depth (PD) and improving clinical attachment level (CAL) in adult periodontitis. Two double-blind, randomized, placebo-controlled multi-center clinical trials (5 centers each) were conducted; pooled data are reported from all 10 centers (447 patients). At baseline, following 1 hour of scaling and root planing (SRP) in patients free of supragingival calculus, the chip was placed in target sites with PD 5 to 8 mm which bled on probing. Chip placement was repeated at 3 and/or 6 months if PD remained > or = 5 mm. Study sites in active chip subjects received either CHX chip plus SRP or SRP alone (to maintain study blind). Sites in placebo chip subjects received either placebo chip plus SRP or SRP alone. Examinations were performed at baseline; 7 days; 6 weeks; and 3, 6, and 9 months. At 9 months significant reductions from baseline favoring the chlorhexidine chip compared with both control treatments were observed with respect to PD (chlorhexidine chip plus SRP, 0.95 +/- 0.05 mm; SRP alone, 0.65 +/- 0.05 mm, P < 0.001; placebo chip plus SRP, 0.69 +/- 0.05 mm, P < 0.001) and CAL (chlorhexidine chip plus SRP, 0.75 +/- 0.06 mm; SRP alone, 0.58 +/- 0.06 mm, P < 0.05; placebo chip plus SRP, 0.55 +/- 0.06 mm, P < 0.05). The proportion of patients who evidenced a PD reduction from baseline of 2 mm or more at 9 months was significantly greater in the chlorhexidine chip group (19%) compared with SRP controls (8%) (P < 0.05). Adverse effects were minor and transient toothache, including pain, tenderness, aching, throbbing, soreness, discomfort, or sensitivity was the only adverse effect that was higher in the chlorhexidine group as compared to placebo (P = 0.042). These data demonstrate that the adjunctive use of the chlorhexidine chip results in a significant reduction of PD when compared with both SRP alone or the adjunctive use of a placebo chip. These multi-center randomized control trials suggest that the chlorhexidine chip is a safe and effective adjunctive chemotherapy for the treatment of adult periodontitis.

A controlled multicenter study of adjunctive use of tetracycline periodontal fibers in mandibular class II furcations with persistent bleeding

The aim of this randomized single-blind multicenter controlled clinical trial was to clinically evaluate the effectiveness of adjunctive local controlled drug delivery in the control of bleeding on probing in mandibular class II furcations during maintenance care. 127 patients presenting with a class II mandibular furcation with bleeding on probing were included in the study. They had been previously treated for periodontitis and were participating in supportive care programs in periodontal specialty practices. Treatments consisted of scaling and root planing with oral hygiene instructions (control) and scaling and root planing and oral hygiene combined with local controlled drug delivery with tetracycline fibers (test). The following outcomes were evaluated at baseline and 3 and 6 months after therapy at the furcation site: bleeding on controlled force probing (BOP), probing pocket depth (PD) and clinical attachment levels (CAL). Levels of oral hygiene and smoking status were also assessed. Both test and controls resulted in significant improvements of BOP and PD at 3 and 6 months. The test treatment, however, resulted in significantly better improvements: BOP decreased by 52% in the control group and by 70% in the test group at 3 months; at 6 months, however, the difference was no longer significant. The test treatment resulted in a 0.5 mm greater reduction of PD than the control at 3 months, the improvement was highly significant but its duration did not extend until the 6 months evaluation. No differences were observed in terms of changes in CAL. These data indicate that addition of tetracycline fibers to mechanical therapy alone resulted in improved control of periodontal parameters during periodontal maintenance of class II mandibular furcations. Short duration of the effect, however, requires further investigations to optimize conservative treatment of these challenging defects.