Periodontal pharmacotherapy - an updated review

Recent advances in the pathogenesis and prevention strategies of dental calculus

Dental calculus severely affects the oral health of humans and animal pets. Calculus deposition affects the gingival appearance and causes inflammation. Failure to remove dental calculus from the dentition results in oral diseases such as periodontitis. Apart from adversely affecting oral health, some systemic diseases are closely related to dental calculus deposition. Hence, identifying the mechanisms of dental calculus formation helps protect oral and systemic health. A plethora of biological and physicochemical factors contribute to the physiological equilibrium in the oral cavity. Bacteria are an important part of the equation. Calculus formation commences when the bacterial equilibrium is broken. Bacteria accumulate locally and form biofilms on the tooth surface. The bacteria promote increases in local calcium and phosphorus concentrations, which triggers biomineralization and the development of dental calculus. Current treatments only help to relieve the symptoms caused by calculus deposition. These symptoms are prone to relapse if calculus removal is not under control. There is a need for a treatment regime that combines short-term and long-term goals in addressing calculus formation. The present review introduces the mechanisms of dental calculus formation, influencing factors, and the relationship between dental calculus and several systemic diseases. This is followed by the presentation of a conceptual solution for improving existing treatment strategies and minimizing recurrence.

Oleogel-based drug delivery for the treatment of periodontitis: current strategies and future perspectives

Periodontitis is the chronic inflammation of tooth-supporting tissues that leads to loss of tooth support if untreated. Conventional therapy for periodontitis (mechanical removal of microbial biofilm and oral hygiene enforcement) is augmented by anti-microbial and anti-inflammatory drugs. These drugs are frequently delivered locally into the periodontal pocket for maximum efficiency and minimum adverse effects. The potential of oleogels for periodontal drug delivery has been discussed and further, the future scope of oleogel-based drug delivery systems in dentistry. An oleogel-based local drug delivery system offers several advantages over other systems. Superior mechanical properties (firmness and compressibility), muco-adhesion, shear thinning, thixotropy, controlled drug release and the ability to incorporate water-insoluble drugs clearly distinguish and highlight the potential of oleogels as periodontal local drug delivery systems. Bigels can combine the qualities of both hydrogels and oleogels to provide a more promising option for drug delivery. However, there is limited evidence concerning oleogels as local drug delivery agents in periodontics. Further studies are needed to discern the clinical efficacy of oleogel-based drug delivery systems.

Investigation of bactericidal effect of a mid-infrared free electron laser on Escherichia coli

The rapid increase in the number of bacteria that are resistant to many commonly used antimicrobial agents and their global spread have become a major problem worldwide. In particular, for periodontal disease, which is a localized infection, there is a growing need for treatment methods that do not primarily involve antimicrobial agents, and antimicrobial photodynamic therapy (aPDT) is attracting attention. In this study, the bactericidal effects of a mid-infrared free electron laser (MIR-FEL) on E. coli were investigated as a basic study to examine the applicability of MIR-FELs, which can selectively excite molecular vibrations due to their wavelength tunability, to aPDT. The optimal irradiation wavelengths to be examined in this study were determined from the infrared spectrum of the bacteria, which was obtained using Fourier transform infrared spectroscopy. Five irradiation wavelengths (6.62, 6.88, 7.14, 8.09 and 9.26 µm) were selected from the FT-IR spectrum, and we found that the bactericidal effects at a wavelength of 6.62 µm were markedly stronger than those observed at the other wavelengths. At this wavelength corresponding to the Amide II band, the bacterial survival rate decreased significantly as the irradiation time increased. On the contrary, irradiation of a neodymium-doped yttrium aluminum garnet (Nd: YAG) laser at 1.06 µm exhibited no distinct bactericidal effect. No morphological changes were observed after MIR-FEL irradiation, suggesting that a bacterial organelle molecule may be the target of MIR-FEL irradiation, but the exact target was not identified. Furthermore, the temperature change induced in the culture medium by the laser irradiation was ± 1.5 °C at room temperature. These results suggest that the bactericidal effects of MIR-FEL are derived from photochemical reactions involving infrared photons, since E. coli is usually killed by heating it to 75 °C for 1 min or longer.

Therapeutic Potential of Polyphenol and Nanoparticles Mediated Delivery in Periodontal Inflammation: A Review of Current Trends and Future Perspectives

Periodontitis is an oral inflammatory process involving the periodontium, which is mainly caused by the invasion of periodontopathogenic microorganisms that results in gingival connective tissue and alveolar bone destruction. Metabolic products of the oral pathogens and the associated host immune and inflammatory responses triggered are responsible for the local tissue destruction. Numerous studies in the past decades have demonstrated that natural polyphenols are capable of modulating the host inflammatory responses by targeting multiple inflammatory components. The proposed mechanism by which polyphenolic compounds exert their great potential is by regulating the immune cell, proinflammatory cytokines synthesis and gene expression. However, due to its low absorption and bioavailability, the beneficial effects of these substances are very limited and it hampers their use as a therapeutic agent. To address these limitations, targeted delivery systems by nanoencapsulation techniques have been explored in recent years. Nanoencapsulation of polyphenolic compounds with different carriers is an efficient and promising approach to boost their bioavailability, increase the efficiency and reduce the degradability of natural polyphenols. In this review, we focus on the effects of different polyphenolic substances in periodontal inflammation and to explore the pharmaceutical significance of polyphenol-loaded nanoparticles in controlling periodontitis, which may be useful for further enhancement of their efficacy as therapeutic agents for periodontal disease.

Impact on Porphyromonas gingivalis of antimicrobial photodynamic therapy with blue light and Rose Bengal in plaque-disclosing solution

OBJECTIVES

Antimicrobial photodynamic therapy (aPDT) in periodontal pockets using lasers is difficult to perform in some cases because of the high cost of irradiation equipment and the narrow irradiation field. The purpose of the present study was to examine the effects of aPDT in combination with a plaque-disclosing solution and blue light-emitting diode (LED), which are used for composite resin polymerization.

METHODS

The reactive oxygen species generated by irradiating 0.001% RB or MB with blue light were analyzed using electron spin resonance spectroscopy. Blue-light exposure was performed at 6.92, 20.76 and 124.6 J. The microorganism to be sterilized was Porphyromonas gingivalis. After aPDT, colony-forming units (CFUs) were measured to estimate cell survival. Carbonylated protein (PC) levels were used to evaluate oxidative stress. All statistical analyses were performed with Tukey's multiple comparisons test or the unpaired t-test.

RESULTS

Singlet oxygen (¹O₂) generation was confirmed by RB+blue LED. ¹O₂ production was significantly greater with the blue LED irradiation of RB than that of MB (p < 0.0001). CFUs were significantly lower in the blue LED-irradiated group than in the non-LED-irradiated group (p < 0.01). The bactericidal effect increased in a time-dependent manner. aPDT increased PC levels. No morphological changes were observed in P. gingivalis.

CONCLUSIONS

The present results suggest that aPDT exerts bactericidal effects against P. gingivalis by increasing oxidative stress through the generation of ¹O₂ in cells. Periodontal disease may be treated by aPDT using the equipment available in dental offices.

Evaluation of Anti-plaque and Anti-inflammatory Effects of Oral Curcumin Gel as Adjunct to Scaling and Root Planing: A Clinical Study

Context:

The adverse effects associated with traditional adjunctive chemical agents in the management of gingivitis has stimulated research into search for alternate molecules including herbal products. Aims-To compare the effects of oral curcumin gel as an adjunct to scaling and root planing (SRP) with the effects achieved by SRP alone by assessing their effects on plaque, gingival inflammation and gingival bleeding.

Materials and Methods:

Sixty patients in the age group of 20–60 years were recruited employing inclusion and exclusion criteria. Study population was randomly divided into two groups. Group A-test group was instructed to use twice daily the experimental curcumin gel after initial SRP. Group B-control group received only SRP. Parameters recorded were plaque index (PI), gingival index (GI) and sulcus bleeding index (SBI) on day 0 (baseline), days 7, 14, and 21 along with subjective assessment of any reported untoward side effect. Data was analyzed statistically.

Results:

The PI, GI and SBI decreased in both the test group and control group from day 0 to day 21 consecutively. Intergroup comparison shows that all the parameters were statistically significant in Group A (P < 0.001) as compared to Group B.

Conclusion:

Curcumin gel has significant antiplaque and anti-inflammatory effect in the treatment of gingivitis and can be effectively employed as an adjunct to SRP.

Comparing the Antimicrobial In Vitro Efficacy of Amoxicillin/Metronidazole against Azithromycin-A Systematic Review

On account of its proven clinical efficacy, the combination of systemically administered amoxicillin and metronidazole is frequently adjuncted to non-operative periodontal therapy and well documented. Potential drawbacks of this regimen, e.g., side effects and problems with the compliance, led to an ongoing search for alternatives. Azithromycin, an antibiotic extensively used in general medicine, has recently found its niche in periodontal therapy as well. This systematic review aimed to analyze the in vitro antimicrobial efficacy of amoxicillin plus metronidazole versus azithromycin. For this purpose, a systematic literature search was performed, and studies published up to 29 March 2018 referenced in Medline, Embase, Cochrane, and Biosis were independently screened by two authors. An additional hand search was performed and studies focusing on the evaluation of in vitro antimicrobial efficacy of amoxicillin + metronidazole or azithromycin on bacteria from the subgingival biofilm were included. English and German language research reports were considered. From 71 identified articles, only three articles were eligible for inclusion. These studies showed heterogeneity in terms of analytical methods and strains explored. However, all studies used multispecies biofilm models for analysis of the antimicrobial activity. Unanimously, studies reported on more pronounced antimicrobial effects when applying the combination of amoxicillin + metronidazole, compared to azithromycin. Based on the few studies available, the combination of amoxicillin + metronidazole seemed to display higher antimicrobial efficacy in vitro than azithromycin.

Development of hydrogels, oleogels, and bigels as local drug delivery systems for periodontitis

Periodontal disease is a chronic inflammation of gum and tissues that surround and support the teeth. Nonsteroidal anti-inflammatory drugs (NSAIDs) can be used in the treatment of periodontitis to ease swelling and inflammation. One approach of treating periodontitis is loading the NSAIDs in local drug delivery systems. Therefore, the objective of this study was to investigate the local delivery of the NSAIDs model drug ibuprofen to treat periodontitis using different types of gel formulations (hydrogel, oleogel, and bigel). Gel formulations were characterized in terms of their rheological properties (flow behavior, viscoelastic, and bioadhesive properties) using a controlled-stress rheometer. The in vitro drug release of ibuprofen from gel formulations was investigated using Franz diffusion cells. Gels exhibited more solid-like (elastic) behavior. The viscosity and viscoelastic properties were in the order of oleogel > bigel > hydrogel, respectively. In bioadhesion study, mucin dispersion/plain ibuprofen-hydrogel mixture showed a frequency-dependent interaction of ΔG' = -31 and ΔG' = + 53 Pa at 1 and 10 rad/s, respectively. A strong positive interaction (ΔG' = + 6000 and +130,667 Pa at 1 and 10 rad/s, respectively) was found in mucin dispersion/plain ibuprofen-oleogel mixture. The extent of the negative interaction increased in mucin dispersion/plain ibuprofen-bigel mixture (ΔG' = -59,000 and -79,375 Pa at 1 and 10 rad/s, respectively). After 6 h, ibuprofen release from hydrogel, oleogel, and bigel was 59.5 ± 2.2, 80.6 ± 3.9, and 94.6 ± 3.2%, respectively. Results showed that the rheological and bioadhesive properties and in vitro drug release were influenced by the type of gel formulations.

Characterization of phenolic compounds in tincture of edibleNepeta nuda: development of antimicrobial mouthwash

The activity of edibleNepeta nudaL. (Lamiaceae) tincture and Listerine towards a selected group of oral pathogenic microorganisms (4 bacterial and 9 fungal strains) has been explored.

Apolipoprotein E Related Co-Morbidities and Alzheimer's Disease

The primary goal of advancement in clinical services is to provide a health care system that enhances an individual's quality of life. Incidence of diabetes mellitus, cardiovascular disease, and associated dementia coupled with the advancing age of the population, have led to an increase in the worldwide challenge to the healthcare system. In order to overcome these challenges, prior knowledge of common, reliable risk factors and their effectors is essential. Oral health constitutes one such relatively unexplored but indispensable risk factor for aforementioned co-morbidities, in the form of poor oral hygiene and tooth loss during aging. Behavioral traits such as low education, smoking, poor diet, neglect of oral health, lack of exercise, and hypertension are few of the risk factors that are shared commonly among these conditions. In addition, common genetic susceptibility traits such as the apolipoprotein E gene, together with an individual's lifestyle can also influence the development of co-morbidities such as periodontitis, atherosclerosis/stroke, diabetes, and Alzheimer's disease. This review specifically addresses the susceptibility of apolipoprotein E gene allele 4 as the plausible commonality for the etiology of co-morbidities that eventually result from periodontal diseases and ultimately progress to dementia.

Effects of Salvia miltiorrhiza ethanolic extract on lipopolysaccharide-induced dental alveolar bone resorption in rats

Background/purpose

Salvia miltiorrhiza (SM) Bunge (Labiatae/Lamiaceae; common name danshen) is a Chinese medicine that improves blood circulation and inhibits inflammatory response. Thus, it is used for the treatment of cardiac diseases and inflammation. In this study, we aimed to evaluate the effect of an ethanolic extract of SM (SME) on the dental alveolar bone resorption induced by bacterial lipopolysaccharide (LPS) in rats.

Materials and methods

An ethanolic extract was prepared from roots of SM. The major constituents of this extract were determined by high-performance liquid chromatography. The activity of the extract was evaluated in a rat model in which the dental alveolar bone resorption was induced by injection of bacterial LPS into the palatal gingiva around the maxillary molar teeth. The effect of SME on the bone resorption was studied by histologic and histomorphometric analysis.

Results

The number of osteoclasts and the percentage of osteoclasts covering the alveolar bone surfaces were significantly increased in the LPS group compared with those in the phosphate-buffered saline (PBS) group. The number and percentage of the osteoclasts on the bony surfaces were significantly reduced in the SME group in comparison with the LPS group, although it was still higher than the numbers observed in the PBS group.

Conclusion

Because SME reduced bone resorption caused by the injections of bacterial LPS in rats, we suggest that SME might have a protective effect on dental alveolar bone resorption in periodontitis.

pH-Responsive Hydrogel With an Anti-Glycation Agent for Modulating Experimental Periodontitis

BACKGROUND

Stimulus-responsive devices have emerged as a novel approach for local drug delivery. This study investigates the feasibility of a novel chitosan-based, pH-responsive hydrogel loaded with N-phenacylthiazolium bromide (PTB), which cleaves the crosslinks of advanced glycation end products on the extracellular matrix.

METHODS

A chitosan-based hydrogel loaded with PTB was fabricated, and the in vitro release profile was evaluated within pH 5.5 to 7.4. BALB/cJ mice and Sprague-Dawley rats were used to evaluate the effects during the induction and recovery phases of periodontitis, respectively, and animals in each phase were divided into four groups: 1) no periodontitis induction; 2) ligature-induced experimental periodontitis (group PR); 3) experimental periodontitis plus hydrogel without PTB (group PH); and 4) experimental periodontitis plus hydrogel with PTB (group PP). The therapeutic effects were evaluated by microcomputed tomographic imaging of periodontal bone level (PBL) loss and histomorphometry for inflammatory cell infiltration and collagen density.

RESULTS

PTB was released faster at pH 5.5 to 6.5 and consistently slower at pH 7.4. In the induction phase, PBL and inflammatory cell infiltration were significantly reduced in group PP relative to group PR, and the loss of collagen matrix was significantly reduced relative to that observed in group PH. In the recovery phase, PBL and inflammatory cell infiltration were significantly reduced, and significantly greater collagen deposition was noted in group PP relative to groups PR and PH at 4 and 14 days after silk removal.

CONCLUSION

Chitosan-based, pH-responsive hydrogels loaded with PTB can retard the initiation of and facilitate the recovery from experimental periodontitis.

Advances in collagen, chitosan and silica biomaterials for oral tissue regeneration: from basics to clinical trials

Different materials have distinct surface and bulk characteristics; each of them potentially useful for the treatment of a particular wound or disease.

A Salvia miltiorrhiza ethanol extract ameliorates tissue destruction caused by experimental periodontitis in rats

BACKGROUND AND OBJECTIVE

Salvia miltiorrhiza Bunge (Labiatae), or Danshen, is a Chinese medicine used for treatment of cardiac diseases by improving blood circulation and inhibiting inflammatory responses. In this study, we aimed to determine whether an ethanol extract of S. miltiorrhiza can ameliorate tissue damage caused by periodontitis.

MATERIAL AND METHODS

An ethanolic extract of S. miltiorrhiza roots was prepared, and its major constituents were determined by HPLC analysis, by comparison with known standards for the major bioactive components. The activity of the extract was evaluated in a rat model in which periodontitis was induced by ligation of a silk suture around the neck of molar teeth. The effects of the S. miltiorrhiza extract on periodontitis were assessed by dental radiography, micro-computed tomography and histology.

RESULTS

The cemento-enamel junction-bone distances among the four different groups of rats were significantly different: the distance was shorter in groups treated with ligation + S. miltiorrhiza extract than in the group treated with ligation only, but was longer than in the nonligated group, regardless of the radiographic methods used. Histology and histometry also indicated a similar trend of less gingival inflammation and alveolar bone destruction in the histological sections from the S. miltiorrhiza extract groups than in those from the ligation group.

CONCLUSION

Because the S. miltiorrhiza extract reduced tissue damage and bone loss caused by ligation-induced periodontitis in rats, we suggest that the S. miltiorrhiza extract might have an ameliorative effect on periodontal tissue destruction during the process of periodontitis.

Susceptibility of Porphyromonas gingivalis and Streptococcus mutans to Antibacterial Effect from Mammea americana

The development of periodontal disease and dental caries is influenced by several factors, such as microorganisms of bacterial biofilm or commensal bacteria in the mouth. These microorganisms trigger inflammatory and immune responses in the host. Currently, medicinal plants are treatment options for these oral diseases. Mammea americana extracts have reported antimicrobial effects against several microorganisms. Nevertheless, this effect is unknown against oral bacteria. Therefore, the aim of this study was to evaluate the antibacterial effect of M. americana extract against Porphyromonas gingivalis and Streptococcus mutans. For this, an experimental study was conducted. Ethanolic extract was obtained from seeds of M. americana (one oil phase and one ethanolic phase). The strains of Porphyromonas gingivalis ATCC 33277 and Streptococcus mutans ATCC 25175 were exposed to this extract to evaluate its antibacterial effect. Antibacterial activity was observed with the two phases of M. americana extract on P. gingivalis and S. mutans with lower MICs (minimum inhibitory concentration). Also, bactericidal and bacteriostatic activity was detected against S. mutans, depending on the concentration of the extract, while on M. americana extract presented only bacteriostatic activity against P. gingivalis. These findings provide important and promising information allowing for further exploration in the future.

Lessons to be learned from periodontitis

PURPOSE OF REVIEW

This article reviews the link between periodontitis and rheumatoid arthritis (RA) with regard to similarities in genetic risk factors and immunopathogenesis. Emphasis is paid to the potential role of the periodontal pathogen Porphyromonas gingivalis in the etiopathogenesis of both periodontitis and RA, in particular by post-translational modification of arginine into citrulline.

RECENT FINDINGS

P. gingivalis, a major periodontal pathogen, is presently known as the only bacterium in the oral flora which contains a peptidyl arginine deiminase enzyme (PAD). This enzyme is necessary for citrullination. As a result, citrullinated proteins and P. gingivalis PAD, PAD2 and PAD4 (expressed by infiltrating neutrophils) are found in periodontal tissues. Autoantibodies directed to citrullinated proteins, so-called anticitrullinated protein antibodies (ACPAs), are found to be present in gingival crevicular fluid originating from inflamed gingival tissue. Furthermore, treatment studies have revealed that nonsurgical periodontal treatment, that is removal of sub-gingival calculus and biofilm deposits, is accompanied by a reduction in the severity of RA.

SUMMARY

In this study the similarities in immune response and tissue degradation between RA and periodontitis are reviewed. It is shown that the two diseases share the same environmental and genetic risk factors, apart from the fact that there is a link between both diseases via citrullination of proteins by human PAD and P. gingivalis PAD.