Effects of combined topical metronidazole and mechanical treatment on the subgingival flora in deep periodontal pockets in cuspids and bicuspids

Supra and subgingival application of antiseptics or antibiotics during periodontal therapy

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

Injectable metronidazole-eluting gelatin-alginate hydrogels for local treatment of periodontitis

Infection of the periodontal pocket presents two major challenges for drug delivery: administration into the periodontal pocket and a high fluid clearance rate in the pocket. The current study aimed to develop and study a novel hydrogel system for delivery of the antibiotic drug metronidazole directly into the periodontal pocket via injection followed by in situ gelation. The natural polymers gelatin and alginate served as basic materials, and their crosslinking using a carbodiimide resulted in a dual hydrogel network. The study focused on the effects of the hydrogel's formulation parameters on the drug release profile and the hydrogel's physical and mechanical properties. A cell viability test was conducted on human fibroblasts. The metronidazole-loaded hydrogels demonstrated a decreasing release rate with time, where most of the drug eluted within 24 h. These hydrogels exhibited fibroblast viability of at least 75% after 24 and 48 h, indicating that they are highly biocompatible. Although the alginate concentration used in this study was relatively low, it had a strong effect on the physical as well as the mechanical properties of the hydrogel. An increase in the alginate concentration increased the crosslinking rate and enabled enhanced entanglement of the 3D structure, resulting in a decrease in the gelation time (less than 10 s) and swelling degree, which are both desired for the studied periodontal application. Increasing the gelatin concentration without changing the crosslinker concentration resulted in significant changes in the physical properties and slight changes in the mechanical properties. Metronidazole incorporation slightly decreased the hydrophilicity of the hydrogel and therefore also its viscosity, and affected the sealing ability and the tensile and compression moduli. The developed hydrogels exhibited controllable mechanical and physical properties, can target a wide range of conditions, and are therefore of high significance in the field of periodontal treatment.

To assess the effectiveness of a chlorhexidine chip in the treatment of chronic periodontitis: A clinical and radiographic study

CONTEXT

Controlled local delivery of disinfecting agents has been demonstrated to be efficient in improving the outcome of periodontal therapy.

AIMS

The aim of the present study was to evaluate the efficacy of a controlled-release biodegradable chlorhexidine chip (Periocol CG) when used as an adjunct to scaling and root planing in the treatment of periodontitis.

SETTINGS AND DESIGN

The study was carried out as randomized controlled two-group parallel clinical trial.

MATERIALS AND METHODS

Forty patients in the age group of 30-65 years suffering from mild to moderate chronic periodontitis, having pocket depth ranging between 5 and 8 mm, were selected for the study. At the screening visit, complete history taking, periodontal examination and full-mouth supragingival scaling was carried out for each patient. At the baseline visit (on the 7(th) day), all clinical parameters and radiographic parameters were recorded at selected sites and patients were randomly assigned to either the control group (group A) or the treatment group (group B). All patients in both the groups received complete subgingival scaling and root planing. Then, in group B, chlorhexidine chip (Periocol CG) was inserted at the selected site. Patients were recalled at 1 month, 2 months and 3 months from the baseline for recording clinical observations, and radiographic parameters were recorded at the end of the study.

STATISTICAL ANALYSIS

Mean, standard deviation, Chi-square test, "t" test for equality of means and paired samples correlations were used.

RESULTS

There was a statistically significant clinical attachment gain, reduction in bleeding index scores, probing pocket depth reduction and bone gain in both the groups, but group B showed better results than group A, and these differences were statistically significant.

CONCLUSIONS

The results of this study show that chlorhexidine chip (PerioCol-CG) is an effective adjunctive therapy to scaling and root planing in the treatment of chronic periodontitis.

Evaluation of two local drug delivery systems as adjuncts to mechanotherapy as compared to mechanotherapy alone in management of chronic periodontitis: A clinical, microbiological, and molecular study

BACKGROUND

Modern concepts of treating inflammatory periodontal disease aim at changes in the subgingival ecosystems within the periodontal pockets to alter the complex microbial community into a microbiota compatible with good periodontal health. Systemic antimicrobial therapy, although effective, involves a relatively high dose with repeated intakes over a prolonged period of time to achieve the required inhibitory concentrations in the sulcular fluid. The adjunctive use of local drug delivery may provide a beneficial response, especially in specific areas where conventional forms of therapy might fail. The aim of this study was to compare the efficacy of two local drug delivery systems, one containing metronidazole and the other containing tetracycline hydrochloride as adjuncts to mechanotherapy in the treatment of chronic periodontitis.

MATERIALS AND METHODS

There were three groups that were labeled as group A (Scaling + Tetracycline), group B (Scaling + Metronidazole), and group C (Scaling alone). A microbiological analysis was carried out to determine the efficacy of these systems in changing the pathogenic flora in deep pockets. In addition, a multiplex polymerase chain reaction was carried out to confirm the presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis (Pg), and Tannerella forsythensis in the flora associated with chronic periodontitis.

RESULTS

There was clinical improvement in groups A and B, which correlated with an improvement in the microbiological parameters; these results were sustained for 90 days following therapy. In Group C, the flora showed a shift towards baseline at the end of 90 days.

CONCLUSIONS

According to this study, both the local antibiotic therapies resulted in greater improvement in microbiological parameters when used as an adjunct to mechanotherapy as compared to mechanotherapy alone.

Chitosan inserts for periodontitis: influence of drug loading, plasticizer and crosslinking on in vitro metronidazole release

Chitosan based metronidazole (MZ) inserts were fabricated by the casting method and characterized with respect to mass and thickness uniformity, metronidazole loading and in vitro metronidazole release kinetics. The fabricated inserts exhibited satisfactory physical characteristics. The mass of inserts was in the range of 5.63 +/- 0.42 to 6.04 +/- 0.89 mg. The thickness ranged from 0.46 +/- 0.06 to 0.49 +/- 0.08 mm. Metronidazole loading was in the range of 0.98 +/- 0.09 to 1.07 +/- 0.07 mg except for batch CM3 with MZ loading of 2.01 +/- 0.08 mg. The inserts exhibited an initial burst release at the end of 24 h, irrespective of the drug to polymer ratio, plasticizer content or cross-linking. However, further drug release was sustained over the next 6 days. Cross-linking with 10% (m/m) of glutaraldehyde inhibited the burst release by approximately 30% and increased the mean dissolution time (MDT) from 0.67 to 8.59 days. The decrease in drug release was a result of reduced permeability of chitosan due to cross-linking.

Effects of Vitamin-B Complex Supplementation on Periodontal Wound Healing

BACKGROUND

Reports have demonstrated that nutrient supplements, in particular vitamin-B complex (Vit-B), can positively influence wound healing processes. However, limited information is available on the effects of Vit-B on periodontal wound healing.

METHODS

A total of 30 patients (13 males, 17 females) presenting with generalized moderate to severe chronic periodontitis were enrolled in this study. All subjects presented > or = two teeth in the same sextant with probing depth (PD) > or =5 mm and bleeding upon probing (BOP) in need of access flap surgery (AFS). This study was a randomized, double-masked, placebo-controlled clinical trial. Subjects were instructed to take one capsule a day of either Vit-B (50 mg of the following: thiamine HCl, riboflavin, niacinamide, d-calcium pantothenate, and pyridoxine HCl; 50 microg each of d-biotin and cyanocobalamin; and 400 mcg of folate) or placebo for 30 days following AFS. Clinical attachment levels (CAL) and N-benzoyl-dl-arginine-2-naphthylamide (BANA) test scores were measured at baseline and at 90 and 180 days following surgical intervention. Assessments of the healing response were also performed using BOP, gingival index (GI), and plaque index (Pl) at baseline and 7, 14, 30, 90, and 180 days. The mean results of each parameter were averaged within a group. Differences between groups were analyzed by using repeated measures analysis of variance (ANOVA).

RESULTS

Both groups experienced comparable levels of PD reduction following AFS (test: -1.57 +/- 0.34; control: -1.50 +/- 0.21). Changes in mean CAL were more favorable in Vit-B supplemented subjects (test: +0.41 +/- 0.12; control: -0.52 +/- 0.23; P = 0.024). Stratified data demonstrated significantly better results for the test group in both shallow (test: -0.08 +/- 0.03; control: -1.11 +/- 0.27; P = 0.032) and deep sites (test: +1.69 +/- 0.31; control: +0.74 +/- 0.23; P = 0.037). No significant differences were observed between groups regarding PI, GI, and BOP. BANA test values were significantly reduced in both groups after surgical treatment and no significant differences were noted between groups.

CONCLUSION

Vitamin B-complex supplement in combination with AFS resulted in statistically significant superior CAL gains when compared to placebo.

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

BACKGROUND

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

RATIONALE

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

FOCUSED QUESTION

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

SEARCH PROTOCOL

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

SELECTION CRITERIA

INCLUSION CRITERIA

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

EXCLUSION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

REVIEWERS' CONCLUSIONS

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

Effect of the enamel matrix derivative Emdogain on the growth of periodontal pathogens in vitro

OBJECTIVES

The aim of this study was to evaluate the effect of Emdogain (EMD), used for periodontal regeneration, on the growth of periodontal pathogens like Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia. For comparison, we studied the effect of EMD on several microbes associated with other oral diseases as well as its effect on non-pathogenic oral inhabitants.

METHODS

Freshly prepared EMD or its vehicle propylene glycol alginate (PGA) alone were added to calibrated suspensions of microbes. As a control, imitating the post-surgical subgingival situation after flap closure, a serum/NaCl-solution mixture was used. Aliquots for growth assays were taken at scheduled times for calculation of colony-forming units and cell densities over an observation period of 24 h. Additionally, EMD was spotted onto selected, newly seeded microbes growing on agar plates to see if growth inhibition zones could be produced.

RESULTS

The study revealed a marked inhibitory effect of EMD on the growth of the gram-negative periodontal pathogens. A. actinomycetemcomitans showed a significant decrease (p=0.012) in viable counts after 24 h when EMD was added at baseline. P. gingivalis and P. intermedia also showed a marked growth reduction in the presence of EMD and in these cultures no viable microbes could be detected anymore after 24 h. In contrast, no significant growth inhibition was observed in gram-positive bacteria.

CONCLUSIONS

The results suggest that EMD has a positive effect on the composition of bacterial species in the post-surgical periodontal wound, by selectively restricting growth of periopathogens that could hamper the wound healing and reduce the outcome of regenerative procedures.