Antimicrobial strategies for treatment of periodontal diseases

Toxin-triggered liposomes for the controlled release of antibiotics to treat infections associated with the gram-negative bacterium, Aggregatibacter actinomycetemcomitans

Antibiotic resistance has become an urgent threat to health care in recent years. The use of drug delivery systems provides advantages over conventional administration of antibiotics and can slow the development of antibiotic resistance. In the current study, we developed a toxin-triggered liposomal antibiotic delivery system, in which the drug release is enabled by the leukotoxin (LtxA) produced by the Gram-negative pathogen, Aggregatibacter actinomycetemcomitans. LtxA has previously been shown to mediate membrane disruption by promoting a lipid phase change in nonlamellar lipids, such as 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-methyl (N-methyl-DOPE). In addition, LtxA has been observed to bind strongly and nearly irreversibly to membranes containing large amounts of cholesterol. Here, we designed a liposomal delivery system composed of N-methyl-DOPE and cholesterol to take advantage of these interactions. Specifically, we hypothesized that liposomes composed of N-methyl-DOPE and cholesterol, encapsulating antibiotics, would be sensitive to LtxA, enabling controlled antibiotic release. We observed that liposomes composed of N-methyl-DOPE were sensitive to the presence of low concentrations of LtxA, and cholesterol increased the extent and kinetics of content release. The liposomes were stable under various storage conditions for at least 7 days. Finally, we showed that antibiotic release occurs selectively in the presence of an LtxA-producing strain of A. actinomycetemcomitans but not in the presence of a non-LtxA-expressing strain. Together, these results demonstrate that the designed liposomal vehicle enables toxin-triggered delivery of antibiotics to LtxA-producing strains of A. actinomycetemcomitans.

Insights into Intra Periodontal Pocket Pathogenesis, Treatment, In Vitro-In Vivo Models, Products and Patents, Challenges and Opportunity

Periodontal disease is a multifactorial pathogenic condition involving microbial infection, inflammation, and various systemic complications. Here, a systematic and comprehensive review discussing key-points such as the pros and cons of conventional methods, new advancements, challenges, patents and products, and future prospects is presented. A systematic review process was adopted here by using the following keywords: periodontal diseases, pathogenesis, models, patents, challenges, recent developments, and 3-D printing scaffolds. Search engines used were "google scholar", "web of science", "scopus", and "pubmed", along with textbooks published over the last few decades. A thorough study of the published data rendered an accurate and deep understanding of periodontal diseases, the gap of research so far, and future opportunities. Formulation scientists and doctors need to be interconnected for a better understanding of the disease to prescribe a quality product. Moreover, prime challenges (such as a lack of a vital testing model, scarcity of clinical and preclinical data, products allowing for high drug access to deeper tissue regions for prolonged residence, lack of an international monitoring body, lack of 4D or time controlled scaffolds, and lack of successful AI based tools) exist that must be addressed for designing new quality products. Generally, several products have been commercialized to treat periodontal diseases with certain limitations. Various strategic approaches have been attempted to target certain delivery regions, maximize residence time, improve efficacy, and reduce toxicity. Conclusively, the current review summarizes valuable information for researchers and healthcare professional to treat a wide range of periodontal diseases.

High-Power Laser Application for Immediate Implant Placement in Infected Sites: A Systematic Review

Objective: The purpose of this study was to review the literatures regarding the treatment outcomes of applying laser to the infected sites in immediate implant placement. The review tended to primarily target a question: does applying high-power laser have any positive effect on infected sites in immediate implant placement? Background: Although immediate placement of dental implants has been referred to as a predictable and successful procedure, it is prone to the presence of infection that interferes with the healing process, and triggers the failure of implants. Materials and methods: A thorough electronic database search was conducted on PubMed/Medline, Embase, Web of Science, Google Scholar, and the Cochrane library in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Two writers worked separately on screening the eligible studies, assessing whether there was a risk of bias, and extracting the required data. Results: Five out of the 60 studies nominated by the database search matched the inclusion criteria. The studies were carried out on a total of 192 patients with 296 implants in all. Ultimately, the study focused on 245 implants whose infected bed had been already decontaminated and prepared with the help of the high-intensity laser, used either alone or in combination with other approaches before implantation. With only nine failures, the implants inserted in infected and irradiated areas had a 96.3% overall survival rate. Conclusions: Taking the limitations of the review into account, the authors arrived at the conclusion that high-power laser irradiation can be beneficial for immediate implant placement in infected sites.

Toxin-Triggered Liposomes for the Controlled Release of Antibiotics to Treat Infections Associated with Gram-Negative Bacteria

Antibiotic resistance has become an urgent threat to health care in recent years. The use of drug delivery systems provides advantages over conventional administration of antibiotics and can slow the development of antibiotic resistance. In the current study, we developed a toxin-triggered liposomal antibiotic delivery system, in which the drug release is enabled by the leukotoxin (LtxA) produced by the Gram-negative pathogen, Aggregatibacter actinomycetemcomitans. LtxA has previously been shown to mediate membrane disruption by promoting a lipid phase change in nonlamellar lipids, such as 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-methyl (N-methyl-DOPE). In addition, LtxA has been observed to bind strongly and nearly irreversibly to membranes containing large amounts of cholesterol. Here, we designed a liposomal delivery system composed of N-methyl-DOPE and cholesterol to take advantage of these interactions. Specifically, we hypothesized that liposomes composed of N-methyl-DOPE and cholesterol, encapsulating antibiotics, would be sensitive to LtxA, enabling controlled antibiotic release. We observed that liposomes composed of N-methyl-DOPE were sensitive to the presence of low concentrations of LtxA, and cholesterol increased the extent and kinetics of content release. The liposomes were stable under various storage conditions for at least 7 days. Finally, we showed that antibiotic release occurs selectively in the presence of an LtxA-producing strain of A. actinomycetemcomitans but not in the presence of a non-LtxA-expressing strain. Together, these results demonstrate that the designed liposomal vehicle enables toxin-triggered delivery of antibiotics to LtxA-producing strains of A. actinomycetemcomitans.

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.

In vitro induction of Entamoeba gingivalis cyst-like structures from trophozoites in response to antibiotic treatment

Background

Entamoeba gingivalis (E. gingivalis) is an anaerobic protozoan that is strongly associated with inflamed periodontal pockets. It is able to invade the mucosal epithelium of the human host, where it can feed on epithelial cells and elicit a severe innate immune response. Unlike other Entamoeba species, it is considered that E. gingivalis cannot form cysts, because it is a non-infectious protozoan. The lack of encystation capability would make it susceptible to periodontal treatment. However, it is not clear how the human host becomes infected with E. gingivalis trophozoites. We investigated the ability of E. gingivalis to encapsulate in response to an unfavorable environment in vitro.

Methods

Different strains of E. gingivalis, isolated from inflamed periodontal pocket samples, were cultured for 8 days in the presence or absence of the antimicrobials amoxycillin and metronidazole. To reveal cyst formation, we investigated the morphology and ultrastructure of the amoeba by light, fluorescence, transmission and scanning electron microscopy. We also used the fluorescent dye calcofluor white M2R to demonstrate chitin present in the cyst wall.

Results

We observed exocysts and an intra-cystic space separating the encapsulated trophozoite from the environment. Remarkably, cysts showed a smooth surface, polygonal edges and smaller size compared to free-living trophozoites. In addition, encapsulated trophozoites that detached from the cyst wall had a dense cytoplasma without phagocytic vesicles. The cyst walls consisted of chitin as in other Entamoba species. The encapsulated trophozoids were mononuclear after antibioticinduced encapsulation.

Discussion

We conclude that E. gingivalis cyst formation has significant implications for dissemination and infection and may explain why established treatment approaches often fail to halt periodontal tissue destruction during periodontitis and peri-implantitis.

Comparative evaluation of 1% melatonin gel in the treatment of intrabony defect: A randomized controlled clinical trial

BACKGROUND

The present study aims to evaluate and compare the efficacy of locally delivered 1% melatonin gel as an adjunct to non-surgical periodontal therapy (NSPT) in treatment of intrabony defect in Stage III periodontitis, clinically, and radiographically using cone-beam computed tomography (CBCT).

METHODS

This split-mouth clinical trial randomly allotted 44 bilateral intrabony defect (in 22 patients) into two groups where Group I was treated with NSPT with locally delivered placebo gel while Group II was treated with NSPT with 1% melatonin gel. The intrabony defect fill measured from cemento-enamel junction (CEJ)-base of the defect (BD), and the difference in the measurement values of CEJ-BD from baseline to 6 months denoting the bone fill and bone volume evaluated at 6 months using CBCT were the primary outcome measures. Secondary outcome measures were change in probing depth (PD), clinical attachment level (CAL), plaque index, and modified sulcus bleeding index recorded at baseline, 3 months, and 6 months.

RESULTS

Both the study groups showed improvements in assessed parameters, however, a significant gain in intrabony defect fill was observed in Group II (1.46 ± 0.58) as compared with Group I (0.50 ± 0.38) and change in bone volume for Group I was 21.4645 ± 8.8980 mm³ and for Group II was 51.8418 ± 30.2329 mm³ with P < 0.0001.The mean reduction in PD and gain in CAL was 3.90 ± 0.78 and 2.94 ± 0.80 in Group II and in Group I it was 3.23 ± 0.90 and 1.96 ± 0.80 (P < 0.0001).

CONCLUSION

The use of 1% melatonin gel as an adjunct to NSPT is more beneficial in achieving better clinical and radiographic outcome at 6 months which indicates that adjunct use of melatonin gel to NSPT as a local drug delivery is preferred when compared with NSPT and placebo gel alone.

Drug-Coated Floss to Treat Gum Diseases: In Vitro and In Vivo Characterization

Treatment of gum disease often requires antibiotic treatment. In this study, our objective was to advance the practicality of drug-coated floss as an intra gum pocket drug delivery system. The initial design of this delivery system has been previously reported by us. Here, we advance the concept further through in vitro and in vivo evaluation. A floss piece was dip coated in the middle section with model molecules leaving free ends for holding. Porcine gum tissues were used ex vivo and in vivo to evaluate the coated floss, including effect of coating thickness on delivery efficiency, ability to deliver more than one type of molecule (one hydrophilic and one hydrophobic), mechanical properties using a scratch test, and finally retention of delivered material in vivo in the porcine model. After reaching a certain coating thickness, the delivery efficiency of the coated floss decreased, indicating the presence of an optimal coating thickness. Hydrophobic and hydrophilic molecules were successfully coated and delivered with high efficiency into gum pockets. The scratch test indicated that the coatings were resilient. Lastly, the in vivo analysis showed that the drug coating was delivered into the porcine gum pocket with about 65% efficiency, and the coatings could maintain extended residency within the gum pocket despite the native adverse environment of the oral cavity. Overall, this data shows that drug-coated floss can act as a drug delivery vehicle and has potential to provide a minimally invasive and practical method for the delivery of drugs into the gum pockets.

Comparative Evaluation of Cost-Effectiveness, Clinical and Microbiological Parameters of Systemic Antibiotics Versus Local Drug Delivery in Aggressive Periodontitis

BACKGROUND

Periodontitis is a biofilm-associated inflammatory disease of the periodontium in which microbial component contributes to its initiation that mainly includes chronic periodontitis and aggressive periodontitis (AgP).

AIM

The present study aimed to ascertain a cost-effective treatment approach in AgP with minimal side effects by comparing systemic antibiotics (SA) and local drug delivery (LDD) as an adjunct to scaling and root planning (SRP). Furthermore, the objectives were to analyze its effect on clinical and microbial parameters.

MATERIALS AND METHODS

The participants were randomly divided into two groups A and B with eleven participants each. Group A was administered with Chlosite Gel [LDD] whereas group B with amoxicillin (AMX) 500 mg + metronidazole (MTZ) 400 mg [SA] thrice daily for 14 days. Clinical parameters such as plaque index (PI), gingival index (GI), clinical attachment level (CAL), and pocket probing depth (PPD)] were recorded at baseline and three months postoperatively. Microbiological parameters i.e Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) counts were also measured at baseline and after three months.

RESULTS

Statistically significant difference was observed in all clinical parameters i.e. PI, GI, CAL, and PPD after three months follow-up in groups A and B. Reduced bacterial load i.e. Aa and Pg was significant at three months in both the groups. However, on comparing the total expenditure of both the groups, group A ranged from 920-1480 ₹ while in group B it ranged from 330-360 ₹. Hence, lower expenditure in group B (3.7 fold) compared to group A was evident.

CONCLUSIONS

Cost-effective approach recommended in the present study is mainly to promote awareness among periodontal patients in the public and private sectors, who refuse to get dental treatment due to fear of high expenditure. This can be attained by incorporating SA as an alternative to LDD in AgP patients.

Coated floss for drug delivery into the gum pocket

The purpose of this study was to develop a drug-coated floss to allow delivery of therapeutics into diseased gum pocket. Periodontal (gum) disease affects nearly 45% of adults over 30 years of age. Bacterial persistence makes treatment challenging. Drug-coated floss is expected to provide a self-administrable and targeted method for drug delivery into the diseased gum pockets. We investigated various types of floss and sutures as potential candidates to coat drug. An un-waxed nylon braided floss was selected and dip-coated with model hydrophilic and hydrophobic drugs either in free form or after encapsulation in poly(lactic-co-glycolic acid) particles. By tuning the drug concentration or the number of times a floss is dipped into the coating solution we were able to coat from as little as 0.4 μg to as high as 1.6 mg of drug. Coated floss was passed within the gum pocket of excised porcine mandibles to demonstrate delivery efficiency up to 91%. Utilizing the porcine jaw in an ex-vivo condition we illustrated the ability of the delivered drug to diffuse into the tissue. Overall, the data illustrates the potential of coated floss as an innovative modality for drug delivery to the gum pocket.

A pilot study to evaluate the effectiveness of adjunctive use of two antimicrobial topical gels in chronic gingivitis

Background

Gingivitis is one of the most prevalent oral disease in humans. The most important etiological factor of gingivitis is dental plaque. Plaque control procedures comprises of several mechanical and chemical methods. Many studies have advocated that chemical plaque control methods can be used successfully as an adjunct to mechanical plaque control procedures. Thus, the aim of this pilot study is to evaluate the effectiveness of two topical antimicrobial gels as an adjunct to mechanical plaque control over a period of 2 weeks in treatment of chronic gingivitis patients.

Material and Methods

This is a single blind, two arm parallel design pilot clinical study including 60 systemically healthy patients with 1) chronic generalized gingivitis (MGI>1), 2) probing depth ≤ 3mm and 3) zero clinical attachment loss. The study participants were randomly assigned into two groups i.e., Group I- Chlorhexidine Gluconate (CHX) gel, Group II- combination gel of Chlorhexidine gluconate and Metronidazole (CHX-MTZ) gel. Clinical parameters viz. Gingival Index (GI) and Modified Sulcus bleeding index (MSBI) were recorded firstly at baseline after Scaling and Root Planing(SRP), and secondly at the end of the study period of two weeks. Intra and inter-group comparisons of clinical parameters were done using appropriate statistical tests.

Results

There was high significant reduction in GI and MSBI scores at the end of 2 weeks period in both the groups. Further, combination gel of Group II (CHX+MTZ) was found to be statistically more effective as compared to Group I (CHX) used alone.

Conclusions

Our study suggests that Chemotherapeutic agents like CHX and combination CHX-MTZ Gel are clinically effective as adjunct to Scaling and Root Planning(SRP) in treatment of Chronic Gingivitis. Further, post statistical comparative analysis has proved CHX-MTZ combination gel regime to be more clinically effective than CHX gel used alone in treatment of Chronic Gingivitis as adjunct to SRP.

Key words:Scaling and Root Planning (SRP), Chronic Gingivitis, Chlorhexidine Gluconate (CHX) gel, Combination (CHX+MTZ) Gel, Metronidazole (MTZ).

Local drug delivery systems as therapeutic strategies against periodontitis: A systematic review

Periodontitis is a chronic inflammation of the soft tissue surrounding and supporting the teeth, which causes periodontal structural damage, alveolar bone resorption, and even tooth loss. Its prevalence is very high, with nearly 60% of the global population affected. Hence, periodontitis is an important public health concern, and the development of effective healing treatments for oral diseases is a major target of the health sciences. Currently, the application of local drug delivery systems (LDDS) as an adjunctive therapy to scaling and root planning (SRP) in periodontitis is a promising strategy, giving higher efficacy and fewer side effects by controlling drug release. The cornerstone of successful periodontitis therapy is to select an appropriate bioactive agent and route of administration. In this context, this review highlights applications of LDDS with different properties in the treatment of periodontitis with or without systemic diseases, in order to reveal existing challenges and future research directions.

[Efficacy of clarithromycin in the adjuvant treatment of chronic periodontitis: a Meta-analysis]

OBJECTIVE

To evaluate the clinical efficacy of clarithromycin (CLM) in the adjuvant treatment of chronic periodontitis systematically, obtain reasonable conclusions through evidence-based medicine, and provide guidance for clinical rational drug use.

METHODS

Literature about CLM in the adjuvant treatment of chronic periodontitis was searched in CNKI, VIP, Wanfang, Chinese Biomedical Literature Database, PubMed, ScienceDirect, and Embase databases from inception to February 2019 using a computer. Meta-analysis was performed on the homogeneous study using RevMan 5.3 software after two independent reviewers screened the literature, evaluated the quality of the study, extracted the data, and evaluated the risk of bias in the included studies.

RESULTS

Six randomized controlled trials were included in 316 subjects. The meta-analysis showed that compared with the scaling and root planning (SRP) group, the probing depth (PD) was reduced in patients with CLM and SRP [MD=-1.00, 95%CI (-1.55, -0.45), P=0.000 04]. Clinical attachment loss was obtained [MD=-0.03, 95%CI (0.43, 0.65), P<0.000 01], and the difference between the groups was statistically significant. The modified sulcus bleeding index (mSBI) was reduced [MD=-0.01, 95%CI (-0.14, 0.19), P=0.66]. No significant difference was observed between the groups, but the decrease in mSBI was more significant in CLM combined with SRP group.

CONCLUSIONS

CLM combined with subgingival SRP can achieve remarkable results in treating chronic periodontitist.

Periodontal tray application of chlorine dioxide gel as an adjunct to scaling and root planing in the treatment of chronic periodontitis

OBJECTIVE

Clinical improvement after periodontal tray application of chlorine dioxide gel as an adjunct to scaling and root planing (SRP) in the treatment of chronic periodontitis was studied for a period of 30 days.

MATERIALS AND METHODS

The tray fabrication was performed in a dental laboratory using the Soft - Tray Sheets (Ultradent™), whereas scaling and root planing were done using ultrasonic scaler and hand instruments. A total of 36 subjects with chronic periodontitis were divided into 3 treatment groups: group I was treated with SRP procedure combined with the prescription-tray application of chlorine dioxide gel; group II was treated with SRP procedure with the application of chlorine dioxide alone; and group III was treated with SRP procedure alone. Clinical parameters examined were probing pocket depth (PPD) and papillary bleeding index (PBI); measurements were taken at baseline (day0) and 30 days after SRP (day 30). Comparison between treatment groups was tested statistically by Kruskal Wallis test and Analysis of Variance (ANOVA).

RESULTS

There were significant differences in the decrease of the average pocket depth and bleeding index in all the 3 treatment groups (P = 0.001). Decreases in the pocket depth of groups I, II, and III were 50.9%, 47.9%, and 27.8%, respectively. Decreases in the papillary bleeding index of groups I, II, and III were 88.2%, 68.9%, and 51.1%, respectively.

CONCLUSION

The application of chlorine dioxide gel using the custom tray after SRP in the treatment of chronic periodontitis showed better clinical improvement in pocket depth reduction and bleeding index compared to SRP alone.

Synergistic effects of LFchimera and antibiotic against planktonic and biofilm form of Aggregatibacter actinomycetemcomitans

Adjunctive use of antibiotics in periodontal treatment have limitations and disadvantages including bacterial resistance. Antimicrobial peptides (AMPs) are potential new agents that can combat bacterial infection. In this study, antimicrobial activity of different concentrations of conventional antibiotics minocycline (MH), doxycycline (DOX), and antimicrobial peptides LL-37, LL-31, Lactoferrin chimera (LFchimera) and Innate Defense Regulator Peptide 1018 (IDR-1018) against Aggregatibacter actinomycetemcomitans ATCC 43718 were determined using colony culturing assay. Subsequently, in vitro activity of the most effective drug and peptide combination was evaluated by checkerboard technique. Impact of the drug and peptide co-administration on biofilm at different stages, i.e., during adhesion and 1-day old biofilm was compared to each of the agents used alone. Results revealed that the killing effects of all AMPs range from 13–100%. In contrast, MH and DOX at 1 and 5 μM showed no killing activity and instead stimulated growth of bacteria. DOX has better killing activity than MH. LFchimera displayed the strongest killing amongst the peptides. Checkerboard technique revealed that combining DOX and LFchimera yielded synergism. Confocal laser scanning microscopy further showed that the combination of DOX and LFchimera caused significant reduction of bacterial adhesion and reduction of biomass, average biofilm thickness and substratum biofilm coverage of 1-day old biofilm compared to DOX and LFchimera alone. In conclusion, LFchimera alone and in combination with DOX exhibited strong antibacterial and anti-biofilm property against A. actinomycetemcomitans. The findings suggest that LFchimera should be considered for development as a new potential therapeutic agent that may be used as an adjunctive treatment for periodontitis.

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

Background

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

Objective

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

Methods

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

Results

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

Conclusions

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

Protective effect and related mechanisms of curcumin in rat experimental periodontitis

Background

Curcumin exhibits anti-inflammatory effects and has been suggested as a treatment for inflammatory diseases. The aim of this study was to investigate the effects of curcumin on the lipopolysaccharide induced inflammatory response in rat gingival fibroblasts in vitro and ligation-induced experimental periodontitis in vivo, and to speculate the possible anti-inflammatory mechanism of curcumin.

Methods

The gingival fibroblasts were incubated with different concentrations of curcumin in the absence or presence of lipopolysaccharide (LPS). Concentrations of interleukin-1β(IL-1β), tumor necrosis factor-α (TNF-α), osteoprotegerin (OPG) and soluble receptor activator of nuclear factor kappa-B ligand (RANKL) culture supernatants of rat gingival fibroblasts were determined by enzyme linked immunosorbent assay. The nuclear fraction of rat gingival fibroblasts was extracted and nuclear factor kappa-B (NF-κB) activation was assessed by western blotting to elucidate related mechanisms. Curcumin was given every two days by oral gavage. The gingival inflammation and alveolar bone loss between the first and second molars were observed by hematoxylin and eosin staining. Collagen fibers were observed by picro-sirius red staining. Alveolar bone loss was assessed by micro-CT analysis.

Results

Curcumin attenuated the production of IL-1β and TNF-α in rat gingival fibroblasts stimulated by LPS, and inhibited the LPS-induced decrease in OPG/sRANKL ratio and NF-κB activation. Curcumin significantly reduced gingival inflammation and modulated collagen fiber and alveolar bone loss in vivo.

Conclusions

curcumin modulates inflammatory activity in rat periodontitis by inhibiting NF-κB activation and decreasing the OPG/sRANKL ratio induced by LPS.

The comparative evaluation of 1% alendronate gel as local drug delivery system in chronic periodontitis in smokers and non smokers: Randomized clinical trial

Introduction

Periodontitis is a progressive disease of microbial origin involving the loss of supporting tissues of the teeth resulting from host inflammatory and immunologic reactions. The standard approach to the prevention and treatment of periodontal diseases for a number of years has been mechanical therapy and if required surgical intervention Researcher thought of creating a treatment modality where by altering the host response, the destructive host mechanisms could be interfered affecting the final outcome of the disease process.

Aim

The present study aims to explore the efficacy of local delivery of a 1% Alendronate (ALN) gel as an adjunct to scaling and root planing (SRP) for the treatment of infrabony periodontal pockets in smokers and non-smoker with Chronic Periodontitis.

Materials and method

60 infrabony periodontal pockets in patients with chronic periodontitis between the age group of 30-50 years were selected. The study consisted of 2 groups smoker and nonsmoker. A gel based drug delivery system of Alendronate was formulated. 0.1 ml alendronate gel and 0.1 ml placebo gel was placed at the experimental and control sites respectively following root planing. Clinical and radiographic parameters were recorded at baseline, three months and six months.

Results

Alendronate was effective in improving clinical and radiographic parameters compared to placebo. Alendronate showed better result in non smoker group when compared with smoker group.

Conclusion

This Study showed improvements in clinical parameters both at the control and experimental sites. However, the experimental sites (Alendronate) showed greater improvement as compared to the control sites (Placebo). A significant gain in alveolar crest height and defect fill was measured radiographically at non smoker Alendronate group.

Metal oxide nanoparticle-functionalized sebacic acid-grafted PHEAM nanocarriers for enriched activity of metronidazole against food borne bacteria: in vitro and in vivo study

Food borne infection is a serious complication caused by Listeria monocytogenes (L. monocytogenes), a dangerous bacteria.

Microbial colonization of the periodontal pocket and its significance for periodontal therapy

The aim of this paper was to evaluate strategies for periodontal therapy from the perspective of periodontal disease being a consequence of microbial colonization of the periodontal pocket environment. In classic bacterial infections the diversity of the microbiota decreases as the disease develops. In most cases of periodontitis, however, the diversity of the flora increases. Most incriminating bacteria are thought to harm tissues significantly only if present in high numbers over prolonged periods of time. Clinical trials have repeatedly demonstrated that scaling and root planing, a procedure that aims to remove subgingival bacterial deposits by scraping on the tooth surface within the periodontal pocket, is effective. At present, for the therapy of any form of periodontal disease, there exists no protocol with proven superiority, in terms of efficiency or effectiveness, over scaling and root planing plus systemic amoxicillin and metronidazole. Some exponents advocate rationing these drugs for patients with a specific microbial profile. However, the evidence for any benefit of bacteriology-assisted clinical protocols is unsatisfactory. Treated sites are subject to recolonization with a microbiota similar to that present before therapy. The degree and speed of recolonization depends on the treatment protocol, the distribution patterns of periodontal microorganisms elsewhere in the oral cavity and the quality of the patient's oral hygiene. To limit the use of antibiotics and to avoid accumulation of harmful effects by repeated therapy, further efforts must be made to optimize procedures addressing the microbial colonization and recolonization of the periodontal pocket.

Evaluation of Turmeric Chip Compared with Chlorhexidine Chip as a Local Drug Delivery Agent in the Treatment of Chronic Periodontitis: A Split Mouth Randomized Controlled Clinical Trial

AIMS AND OBJECTIVE

The aim of this study was to evaluate and compare the effect of chlorhexidine (CHX) chip and turmeric chip as a local drug delivery (LDD) agent in the treatment of patients with chronic periodontitis.

MATERIALS AND METHODS

A total of 120 sites with pocket depths 5-8 mm were chosen as a split mouth design at 3 sites in the same patient. Selected sites were randomly divided into three groups to receive CHX chip in addition to scaling and root planing (SRP) in group A, turmeric chip in addition to SRP in group B, and SRP only in group C. Clinical parameters, that is, plaque index (PI), gingival index (GI), probing pocket depth (PPD), and relative attachment level (RAL) were recorded at baseline, 1 month, and 3 months interval.

RESULT

On applying statistical analysis, results revealed that there was a significant reduction in all the clinical parameters, that is, PI, GI, PPD, and gain in RAL from baseline to 1 month and 3 months in all the three groups. These results were found to be significantly high in the CHX group and turmeric group than in the SRP group. Also, the results in both the test groups were maintained till the end of the study periods, but SRP group showed a significant deterioration after 1 month as was seen by increase in PPD and decrease in RAL scores after 3 months in the SRP group.

CONCLUSION

Both the treatment modalities with the application of LDD as an adjunct to SRP proved to be equally beneficial in the treatment of chronic periodontitis.

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

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

Systemic antibiotics in the treatment of periodontitis

Despite the fact that several clinical studies have shown additional benefits when certain systemic antibiotics are used as adjuncts to periodontal treatment, clear guidelines for the use of these agents in the clinical practice are not yet available. Basic questions concerning the use of systemic antibiotics to treat periodontitis remain unanswered, such as: which drug(s) should be used; which patients would most benefit from treatment; which are the most effective protocols (i.e. doses and durations); and in which phase of the mechanical therapy should the drug(s) be administered? Although not all of those questions have been directly addressed by controlled randomized clinical trials, recent concepts related to the ecology of periodontal diseases, as well as the major advances in laboratory and clinical research methods that have occurred in the past decade, have significantly broadened our knowledge in this field. This article endeavored to provide a 'state of the art' overview on the use of systemic antibiotics in the treatment of periodontitis, based on the most recent literature on the topic as well as on a compilation of data from studies conducted at the Center of Clinical Trials at Guarulhos University (São Paulo, Brazil) from 2002 to 2012.

Efficacy of doxycycline release collagen membrane on surgically created and contaminated defects in rat tibiae: A histopathological and microbiological study

BACKGROUND

The effects of systemic antibiotics on controlling infective pathogens after guided bone regeneration(GBR) procedures especially in membrane exposures are limited. However, local administrations of antibiotics are rare in GBR techniques.

AIM

The aim of this study was to investigate the osteogenesis potential and the antibacterial effect of a doxycycline releasing collagen membrane in surgically created and contaminated defects in rat tibiae.

MATERIAL AND METHODS

Defects were created in 20 rats that were randomly divided in to two groups: control group (defect contaminated by Porphyromonas gingivalis, filled with bone graft and covered by collagen membrane); test group (defect contaminated by P. gingivalis filled with bone graft and covered by collagen membrane containing 1mg/cm(2) doxycycline. Animals were sacrificed post surgically on the 14th day for microbiologic evaluation and on the 28th day for histopathological evaluation.

RESULTS

The degree of osteogenesis in the test group was seen to be significantly higher than control group (p: 0.011; p<0.05). Furthermore in test group, no bacterial growth was observed. The bacteria counts were determined between 1×104 and 268×104CFU/g with a median of 1.32×104 for control group.

CONCLUSIONS

Within the limitations of this study, the results of the present study suggests that the use of a doxycycline releasing membrane has a positive effect on contaminated GBR procedures for limiting P. gingivalis infections leading to bone formation following GBR procedures in a rat model.

Comparison of glycated hemoglobin levels in individuals without diabetes and with and without periodontitis before and after non-surgical periodontal therapy

BACKGROUND

Only a few studies have examined the association between periodontitis and glycated hemoglobin (HbA1c) levels in individuals without diabetes. The aim of this study is to compare HbA1c levels in individuals without diabetes and with and without periodontitis before and after non-surgical periodontal therapy.

METHODS

This comparative study was done on individuals without diabetes who were 35 to 65 years old. Group A consisted of 30 individuals without periodontitis, and group B consisted of 30 individuals with periodontitis. Body mass indices and clinical parameters, including oral hygiene index-simplified (OHI-S) score, gingival index (GI), probing depth (PD), clinical attachment level (CAL), and HbA1c level, of all participants were recorded. All participants received non-surgical periodontal therapy (scaling and root planing). After 3 months, all participants were reexamined, and clinical parameters and HbA1c levels were evaluated and compared to baseline values.

RESULTS

There were significant differences between group A and group B in regard to baseline OHI-S, GI, PD, and HbA1c (P <0.05). There was no clinical attachment loss in group A, either at baseline or after 3 months. At the end of 3 months, group B showed improvement in all clinical parameters (P <0.05) and their HbA1c levels also significantly decreased (P <0.05), although the values never reached those of group A.

CONCLUSION

The HbA1c levels of individuals without diabetes and with periodontitis (group B) were significantly reduced 3 months after non-surgical periodontal therapy, although they never reached the same levels as those of the individuals without diabetes or periodontitis (group A).

Adjunctive use of antibiotics in periodontal therapy

Periodontal diseases are infectious diseases with a mixed microbial aetiology and marked inflammatory response leading to destruction of underlying tissue. Periodontal therapy aims to eliminate pathogens associated with the disease and attain periodontal health. Periodontitis is generally treated by nonsurgical mechanical debridement and regular periodontal maintenance care. Periodontal surgery may be indicated for some patients to improve access to the root surface; however, mechanical debridement alone may not be helpful in all cases. In such cases, adjunctive systemic antibiotic therapy remains the treatment of choice. It can reach microorganisms at the base of the deep periodontal pockets and furcation areas via serum, and also affects organisms residing within gingival epithelium and connective tissue. This review aims to provide an update on clinical issues regarding when and how to prescribe systemic antibiotics in periodontal therapy. The points discussed are the mode of antibiotic action, susceptible periodontal pathogens, antibiotic dosage, antibiotic use in treatment of periodontal disease, and mechanism of bacterial resistance to each antibiotic.

Evaluation of efficacy of chlorhexidine intracanal medicament on the periodontal healing of concomitant endodontic-periodontal lesions without communication: an interventional study

BACKGROUND

Treatment of concomitant endodontic-periodontal lesions remains a challenge in clinical practice and requires effective endodontic and regenerative periodontal therapy. Among other factors, cross seeding and recolonization of flora may affect the outcome of periodontal therapy. Intracanal medicaments have been shown to exert antimicrobial activity on the external root surface, and local delivery of antimicrobials has been suggested to be a complementary approach in the management of periodontitis. Therefore, the objective of this study is to determine the influence of chlorhexidine (CHX) intracanal medicament on the clinical outcomes of therapy.

METHODS

Thirty-one patients were divided into two treatment groups: 1) open flap debridement (OFD) in endodontically treated teeth (control); and 2) OFD in endodontically treated teeth with CHX placed in the coronal space (test). The clinical variables evaluated were probing depth (PD), clinical attachment level (CAL), and percentage of sites with PD ≥5 mm. Reevaluation was performed at 3 and 6 months post-surgery.

RESULTS

Both treatments resulted in improvement in all the clinical variables evaluated. Postoperative measurements from test and control groups showed reductions in mean PD of 2.22 ± 1.27 and 0.91 ± 0.81 mm, mean CAL gains of 2.16 ± 1.12 and 0.60 ± 0.93 mm, and 43.33% ± 31.37% and 17.71% ± 14.23% reduction in sites with PD ≥5 mm. Significantly more PD reduction, CAL gain, and percentage reduction in sites with PD ≥5 mm were observed in the test group at 6 months (P <0.05).

CONCLUSION

CHX may be used as an effective intracanal medicament for promoting periodontal healing in concomitant endodontic-periodontal lesions.

Bacterial adhesion to antibiotic-loaded guided tissue regeneration membranes - a scanning electron microscopy study

BACKGROUND/PURPOSE

Bacterial contamination of sites undergoing guided tissue regeneration (GTR) therapy may reduce the efficiency of periodontal regeneration. This study compared bacterial adhesion onto various GTR membranes incorporated with antibiotics.

METHODS

Three barrier membranes, including expanded polytetrafluoroethylene (ePTFE) membrane, collagen membrane, and glycolide fiber membrane, were loaded with tetracycline or amoxicillin. The adhesion of Streptococcus mutans and Aggregatibacter actinomycetemcomitans onto the GTR membranes with or without antibiotics was analyzed using the scanning electron microscopy (SEM) analysis.

RESULTS

The SEM analysis showed no apparent alteration in the physical structure of the membranes loaded with antibiotics. Both S. mutans and A. actinomycetemcomitans attached best on the collagen membranes, followed by the ePTFE membranes, and then the glycolide fiber membranes without antibiotics. Moreover, higher numbers of bacteria were observed on the fibril areas than on the laminar areas of the ePTFE membranes. The amounts of attached bacteria on the GTR membranes increased after longer incubation. Incorporation of tetracycline or amoxicillin greatly reduced the adhesion of S. mutans and A. actinomycetemcomitans onto all of the GTR membranes examined.

CONCLUSION

Incorporation of tetracycline or amoxicillin greatly reduced adhesion of S. mutans or A. actinomycetemcomitans on the ePTFE, glycolide fiber, or collagen membranes. This finding indicates that it is valuable and effective to use the antibiotic-loaded GTR membranes for periodontal regeneration therapy.

Systemic anti-microbial agents used in periodontal therapy

Periodontitis is an infectious disease with marked inflammatory response, leading to destruction of underlying tissues. The aim of periodontal therapy is to eradicate the pathogens associated with the disease and attain periodontal health. This is achieved by non-surgical and surgical therapy; however, mechanical debridement and topical application of antiseptics may not be helpful in all cases. In such cases, adjunctive systemic antibiotic therapy remains the treatment of choice. It can reach micro-organisms at the base of the deep periodontal pockets and furcation areas via serum, and also affect organisms residing within gingival epithelium and connective tissue. Before advising any anti-microbial agent, it is necessary to have knowledge of that agent. The aim of this review article is to provide basic details of each systemic anti-microbial agent used in periodontal therapy. The points discussed are its mode of action, susceptible periodontal pathogens, dosage, its use in treatment of periodontal disease, and mechanism of bacterial resistance to each anti-microbial agent. It might be of some help while prescribing these drugs.

Mechanisms of action of systemic antibiotics used in periodontal treatment and mechanisms of bacterial resistance to these drugs

Antibiotics are important adjuncts in the treatment of infectious diseases, including periodontitis. The most severe criticisms to the indiscriminate use of these drugs are their side effects and, especially, the development of bacterial resistance. The knowledge of the biological mechanisms involved with the antibiotic usage would help the medical and dental communities to overcome these two problems. Therefore, the aim of this manuscript was to review the mechanisms of action of the antibiotics most commonly used in the periodontal treatment (i.e. penicillin, tetracycline, macrolide and metronidazole) and the main mechanisms of bacterial resistance to these drugs. Antimicrobial resistance can be classified into three groups: intrinsic, mutational and acquired. Penicillin, tetracycline and erythromycin are broad-spectrum drugs, effective against gram-positive and gram-negative microorganisms. Bacterial resistance to penicillin may occur due to diminished permeability of the bacterial cell to the antibiotic; alteration of the penicillin-binding proteins, or production of β-lactamases. However, a very small proportion of the subgingival microbiota is resistant to penicillins. Bacteria become resistant to tetracyclines or macrolides by limiting their access to the cell, by altering the ribosome in order to prevent effective binding of the drug, or by producing tetracycline/macrolide-inactivating enzymes. Periodontal pathogens may become resistant to these drugs. Finally, metronidazole can be considered a prodrug in the sense that it requires metabolic activation by strict anaerobe microorganisms. Acquired resistance to this drug has rarely been reported. Due to these low rates of resistance and to its high activity against the gram-negative anaerobic bacterial species, metronidazole is a promising drug for treating periodontal infections.

Statins: A new era in local drug delivery

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

Systemic antibiotic therapy in periodontics

Systemic antibiotics in conjunction with scaling and root planing (SRP), can offer an additional benefit over SRP alone in the treatment of periodontitis, in terms of clinical attachment loss (CAL) and pocket depth change, and reduced risk of additional CAL loss. However, antibiotics are not innocuous drugs. Their use should be justified on the basis of a clearly established need and should not be substituted for adequate local treatment. The aim of this review is to discuss the rationale, proper selection, dosage and duration for antibiotic therapy so as to optimize the usefulness of drug therapy.

Evaluation of efficacy of tetracycline fibers in conjunction with scaling and root planing in patients with chronic periodontitis

AIM

The objective of this study was to compare the efficacy of scaling and root planing (SRP) alone versus tetracycline fiber therapy used adjunctively with SRP in the treatment of chronic periodontitis sites in maintenance patients.

MATERIALS AND METHODS

A total of 30 patients with a diagnosis of chronic periodontitis (60 localized chronic periodontitis sites) in the age group of 35 to 55 were selected. None of these patients had received any surgical or non-surgical periodontal therapy and had sites of periodontal pockets measuring 4-7 mm clinically and demonstrated radiographic evidence of moderate bone loss. Two non-adjacent sites in separate quadrants were selected in each patient for monitoring based on criteria that the sites had localized chronic periodontitis. Plaque index (PI) (sillness and loe) and Gingival-bleeding index (GI) (loe and sillness) were measured at baseline and 15(th), 30(th), 60(th), and 90(th)day. Clinical pocket depth (PD) and microbial analysis (MA) were analyzed at baseline and 90(th) day.

RESULTS

At 0 and 3 months adjunctive tetracycline fiber therapy was significantly better in reducing PI, GBI, (P<0.001) than S and RP alone. In comparison, the reduction in the PD was non-significant at 0 and 3 months (P<0.001). The microbial analysis showed significant reduction in Porphyromonas gingivalis and Prevotella intermedia though there was no significant reduction in the Actinobacillus actinomycetemcomitans.

CONCLUSION

Overall, these results indicate that fiber therapy significantly enhanced the effectiveness of SRP in the management of chronic periodontitis.

Use of minocycline as systemic antimicrobial therapy in refractory periodontitis with chronic gingival enlargement

Periodontal disease is a multifactorial disease having various risk factors, but a dynamic interaction between bacterial products and host response in association with genetic and environmental factors is considered as the primary cause for periodontal tissue destruction in periodontitis. This bacterial-host interaction which is ever-so-present in periodontitis directs us toward utilizing antimicrobial agents along with the routine mechanical debridement. This case report present a case of a female patient with recurrent periodontal infections with gingival enlargement treated with systemic Minocycline in conjunction with the conventional non-surgical approach.

In vitro and in vivo investigation of drug-eluting implants for the treatment of periodontal disease

This paper developed solvent-free drug-eluting implants for metronidazole delivery for the treatment of periodontal disease and investigated the characteristics of the drug's release from the implants, both in vitro and in vivo, using an HPLC assay. The metronidazole exhibited a two-stage release behavior in vitro with an initial burst release followed by a diffusion-controlled release and then a secondary burst release. The accumulated drug release reached 100% on the 18th day, and the drug-eluting implant was totally dissolved on the same day. Additionally, the drug-eluting disks were implanted within the sub-gingival space of both lower incisors of six rabbits. The curve of in vivo drug release was smoother and showed a predominantly diffusion-controlled release. The implants were totally dissolved at 2 weeks after implantation. The concentration of metronidazole remained above the MIC(90) during the entire investigation.

Evaluation of commercially available biodegradable tetracycline fiber therapy in chronic periodontitis

BACKGROUND

Chronic periodontitis is an inflammatory disorder caused by dental plaque having mixed microbial flora. The different treatment modalities available to treat this disease are aimed at removal of micro-organisms from both hard and soft tissues. Systemic as well as local anti-microbial agents are helpful adjuncts in reducing microbes especially in inaccessible areas along with mechanical debridement therapy.

MATERIALS AND METHODS

The study was conducted in a split mouth design. Thirty-five patients having at least two non-adjacent sites in different quadrants with periodontal pockets ≥5 mm and with bleeding on probing at initial visit were selected. The selected sites were treated with both scaling and root planing plus tetracycline fibers or with scaling and root planing alone. Baseline and follow-up measurements included plaque index, gingival index, probing pocket depth, and clinical attachment level.

RESULT

Both treatment modalities were affective in improving clinical parameters over three months' observation period. The combined antimicrobial and mechanical debridement therapy has shown better results as compared with scaling and root planing alone.

CONCLUSION

Application of tetracycline in modified collagen matrix following scaling and root planing might be beneficial in treatment of chronic periodontitis and improving periodontal parameters for 3-month duration.

Formulation and evaluation of PLA and PLGA in situ implants containing secnidazole and/or doxycycline for treatment of periodontitis

The purpose of this study is to formulate in situ implants containing doxycycline hydrochloride and/or secnidazole that could be used in the treatment of periodontitis by direct periodontal intrapocket administration. Biodegradable polymers [poly (lactide) (PLA) and poly (lactide-co-glycolide) (PLGA)], each polymer in two concentrations 25%w/w, 35%w/w were used to formulate the in situ implants. The rheological behavior, in vitro drug release and the antimicrobial activity of the prepared implants were evaluated. Increasing the concentration of each polymer increases the viscosity and decreases the percent of the drugs released after 24 h. PLA implants showed a slower drugs release rate than PLGA implants in which the implants composed of 25% PLGA showed the fastest drugs release. The in vitro drug release and antimicrobial activity results were compared with results of Atridox. Results revealed that the pharmaceutical formulation based on 25% PLGA containing secnidazole and doxycycline hydrochloride has promising activity in treating periodontitis in comparison with Atridox.

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.

Effects of metronidazole plus amoxicillin as the only therapy on the microbiological and clinical parameters of untreated chronic periodontitis

AIM

To determine the effect of metronidazole plus amoxicillin (M+A) as the sole therapy, on the subgingival microbiota of chronic periodontitis.

MATERIAL AND METHODS

Twenty-two patients with untreated chronic periodontitis were randomly assigned to a group that received M+A for 7 days, or to a group receiving scaling and root planing (SRP) and two placebos. Clinical measurements including sites with plaque, bleeding on probing (BOP), probing depth (PD) and attachment level (AL) were made at baseline, 3, 6, 9 and 12 months. Subgingival plaque samples were taken from all teeth at baseline 3, 6, 9 and 12 months for the counts of 40 subgingival species using checkerboard DNA-DNA hybridization.

RESULTS

Mean PD was reduced from 2.80+/-0.45 at baseline to 1.95+/-0.05 at 12 months (P<0.001) and from 2.39+/-0.41 to 1.95+/-0.10 (P<0.001) in the M+A- and SRP-treated patients, respectively. Corresponding values for relative mean AL were 10.07+/-1.30-9.77+/-0.34 (P<0.001) and 9.94+/-0.28-9.77+/-0.26 (P<0.001). Percentage of sites exhibiting BOP were 40.6+/-18.3-14.0+/-1.4 (P<0.001), and 38.5+/-5.1-19.0+/-2.8 (P<0.001) in the M+A and SRP groups, respectively. Mean total DNA probe counts and counts of the majority of the 40 test species were significantly reduced over time in both groups, with no significant differences detected at any time point between groups. At 12 months many of the species were still present at significantly lowered levels compared with their baseline counts in both groups.

CONCLUSIONS

Changes in clinical and microbiological parameters were similar after receiving systemically administered M+A as the sole therapy or after receiving SRP only.