Azithromycin as an adjunct to non-surgical periodontal therapy: a systematic review

Antibiotic resistance in the microbiota of periodontitis patients: an update of current findings

Systemic antibiotics are an effective adjunct in the treatment of periodontitis, but their judicious use is necessary as antimicrobial resistance is a growing global concern. This review aims to explore the current understanding and insight related to antibiotic resistance in the subgingival microbiota of periodontitis patients. A search of MEDLINE (PubMed) was carried out from 1 January 2012 to 25 November 2021 for studies related to antibiotic resistance in periodontitis patients. Of the 90 articles identified, 12 studies were selected for inclusion. A significant incidence of antibiotic resistant isolates was reported for Porphyromonas gingivalis, Prevotella intermedia, Prevotella denticola, Prevotella melaninogenica, Fusobacterium nucleatum, Tanerella forsythia, Aggretibacter actinomycetemcomitans, Streptococcus constellatus, Streptococcus intermedius, and Parvimonas micra, but resistance to specific antibiotics did not reach above 10% of isolates in most studies except for amoxicillin resistance in Aggretibacter actinomycetemcomitans. The highest frequency of resistance across all bacterial species was for amoxicillin, clindamycin, and metronidazole. However, resistance patterns were widely variable across geographical locations, and the high heterogeneity between antibiotic-resistant isolates across studies precludes any clinical recommendations from this study. Although antibiotic resistance has yet to reach critical levels in periodontitis patients, an emphasis on antibiotic stewardship interventions such as point-of-care diagnostics and education for key stakeholders is needed to curb a growing problem.

A novel macrolide-Del-1 axis to regenerate bone in old age

Aging is associated with increased susceptibility to chronic inflammatory bone loss disorders, such as periodontitis, in large part due to the impaired regenerative potential of aging tissues. DEL-1 exerts osteogenic activity and promotes bone regeneration. However, DEL-1 expression declines with age. Here we show that systemically administered macrolide antibiotics and a non-antibiotic erythromycin derivative, EM-523, restore DEL-1 expression in 18-month-old ("aged") mice while promoting regeneration of bone lost due to naturally occurring age-related periodontitis. These compounds failed to induce bone regeneration in age-matched DEL-1-deficient mice. Consequently, these drugs promoted DEL-1-dependent functions, including alkaline phosphatase activity and osteogenic gene expression in the periodontal tissue while inhibiting osteoclastogenesis, leading to net bone growth. Macrolide-treated aged mice exhibited increased skeletal bone mass, suggesting that this treatment may be pertinent to systemic bone loss disorders. In conclusion, we identified a macrolide-DEL-1 axis that can regenerate bone lost due to aging-related disease.

Erythromycin Restores Osteoblast Differentiation and Osteogenesis Suppressed by Porphyromonas gingivalis Lipopolysaccharide

The macrolide erythromycin (ERM) inhibits excessive neutrophil accumulation and bone resorption in inflammatory tissues. We previously reported that the expression of developmental endothelial locus-1 (DEL-1), an endogenous anti-inflammatory factor induced by ERM, is involved in ERM action. Furthermore, DEL-1 is involved in the induction of bone regeneration. Therefore, in this study, we investigated whether ERM exerts an osteoblastogenic effect by upregulating DEL-1 under inflammatory conditions. We performed in vitro cell-based mechanistic analyses and used a model of Porphyromonas gingivalis lipopolysaccharide (LPS)-induced periodontitis to evaluate how ERM restores osteoblast activity. In vitro, P. gingivalis LPS stimulation suppressed osteoblast differentiation and bone formation. However, ERM treatment combined with P. gingivalis LPS stimulation upregulated osteoblast differentiation-related factors and Del1, indicating that osteoblast differentiation was restored. Alveolar bone resorption and gene expression were evaluated in a periodontitis model, and the results confirmed that ERM treatment increased DEL-1 expression and suppressed bone loss by increasing the expression of osteoblast-associated factors. In conclusion, ERM restores bone metabolism homeostasis in inflammatory environments possibly via the induction of DEL-1.

Effect of Administration of Azithromycin and/or Probiotic Bacteria on Bones of Estrogen-Deficient Rats

The gut microbiota plays an important role in maintaining homeostasis, including that of the skeletal system. Antibiotics may affect the skeletal system directly or indirectly by influencing the microbiota. Probiotic bacteria have been reported to favorably affect bones in conditions of estrogen deficiency. The aim of this study was to investigate the effects of azithromycin (AZM) administered alone or with probiotic bacteria (Lactobacillus rhamnosus; LR) on bones in estrogen-deficient rats. The experiments were carried out on mature rats divided into five groups: non-ovariectomized (NOVX) control rats, ovariectomized (OVX) control rats, and OVX rats treated with: LR, AZM, or AZM with LR. The drugs were administered for 4 weeks. Serum biochemical parameters, bone mineralization, histomorphometric parameters, and mechanical properties were examined. Estrogen deficiency increased bone turnover and worsened cancellous bone microarchitecture and mechanical properties. The administration of LR or AZM slightly favorably affected some skeletal parameters of estrogen-deficient rats. The administration of AZM with LR did not lead to the addition of the effects observed for the separate treatments, indicating that the effects could be microbiota-mediated.

Current Concepts in the Management of Periodontitis

Periodontitis is a common disorder affecting >40% of adults in the United States. Globally, the severe form of the disease has a prevalence of 11%. In advanced cases, periodontitis leads to tooth loss and reduced quality of life. The aetiology of periodontitis is multifactorial. Subgingival dental biofilm elicits a host inflammatory and immune response, ultimately leading to irreversible destruction of the periodontium (i.e. alveolar bone and periodontal ligament) in a susceptible host. In order to successfully manage periodontitis, dental professionals must understand the pathogenesis, primary aetiology, risk factors, contributing factors and treatment protocols. Careful diagnosis, elimination of the causes and reduction of modifiable risk factors are paramount for successful prevention and treatment of periodontitis. Initial non-surgical periodontal therapy primarily consists of home care review and scaling and root planing. For residual sites with active periodontitis at periodontal re-evaluation, a contemporary regenerative or traditional resective surgical therapy can be utilised. Thereafter, periodontal maintenance therapy at a regular interval and long-term follow-ups are also crucial to the success of the treatment and long-term retention of teeth. The aim of this review is to provide current concepts of diagnosis, prevention and treatment of periodontitis. Both clinical and biological rationales will be discussed.

The Effect of Acknowledged and Novel Anti-Rheumatic Therapies on Periodontal Tissues-A Narrative Review

Rheumatoid arthritis (RA) and periodontal disease (PD) are chronic complex inflammatory diseases with several common susceptibility factors, especially genetic and environmental risk factors. Although both disorders involve a perturbation of the immune-inflammatory response at multiple levels, one major difference between the two is the different locations in which they develop. RA is triggered by an exaggerated autoimmune response that targets joints, while periodontal disease occurs as a consequence of the subgingival periodontopathogenic microbiota. Current treatment models in both pathologies involve the stratification of patients to allow therapeutic individualization according to disease stage, complexity, progression, lifestyle, risk factors, and additional systemic diseases. Therapeutic guidelines for RA comprise of five main classes of drugs: non-steroidal anti-inflammatory drugs (NSAIDs), analgesics, glucocorticoids, and disease-modifying anti-rheumatic drugs (DMARDs): biologic and non-biologic. Although various treatment options are available, a definitive treatment remains elusive, therefore research is ongoing in this area. Several alternatives are currently being tested, such as matrix metalloproteinases (MMP) inhibitors, toll-like receptors (TLR) blockers, pro-resolution mediators, anti-hypoxia inducing factors, stem cell therapy, NLRP3 inhibitors and even natural derived compounds. Although the link between PD and rheumatoid arthritis has been investigated by multiple microbiology and immunology studies, the precise influence and causality is still debated in the literature. Furthermore, the immunomodulatory effect of anti-rheumatic drugs on the periodontium is still largely unknown. In this narrative review, we explore the mechanisms of interaction and the potential influence that anti-rheumatoid medication, including novel treatment options, has on periodontal tissues and whether periodontal health status and treatment can improve the prognosis of an RA patient.

Systemic azithromycin as an adjunct to scaling and root planing in patients with stage III/IV periodontitis: 12-month results of a randomized controlled clinical trial

OBJECTIVES

To determine whether azithromycin (AZI) as an adjunct to scaling and root planing (SRP), when compared to placebo, decreases the number of sites demonstrating pocket depth (PD) ≥ 5 mm and bleeding on probing (BOP) 12 months post-treatment in stage III/IV periodontitis patients.

MATERIALS AND METHODS

In a double-blind randomized parallel-arm placebo-controlled trial, 40 stage III/IV periodontitis patients received steps 1 and 2 of periodontal treatment in two sessions within 7 days. Patients then received systemic antibiotic therapy (n = 20; AZI 500 mg/day, 3 days) or placebo (n = 20). Additional instrumentation of residual diseased sites (DS) - sites with PD ≥ 5 mm and BOP - was performed at the 3-, 6- and 9-month follow-ups. The primary outcome variable was the number of DS at the 12-month re-evaluation. Using a multivariate multilevel logistic regression model, the effects of gender, age, antibiotic therapy, presence of Porphyromonas gingivalis or Aggregatibacter actinomycetemcomitans, smoking, tooth being a molar and interdental location were evaluated.

RESULTS

The number of DS after 12 months was similar in the test (median (Me) = 4, interquartile range (IQR) = 0-6) and control (Me = 3, IQR = 1-6.5) groups. Both groups showed substantial but equivalent improvements in periodontal parameters, with no intergroup differences at initially shallow or deep sites. The logistic regression showed a lower odds ratio (OR) for the healing of DS on molars (OR = 0.29; p < 0.001) and in smokers (OR = 0.36; p = 0.048).

CONCLUSION

Stage III/IV periodontitis patients showed significant but comparable improvements in periodontal parameters and the number of residual DS at the 12-month revaluation regardless of treatment type. This may have been the result of the additional instrumentation received by patients at residual DS in both treatment groups.

CLINICAL RELEVANCE

Treatment with AZI + SRP provided no additional benefits after 12 months in terms of periodontal parameters or the number of persisting sites with PD ≥ 5 mm + BOP as compared to SRP plus placebo.

TRIAL REGISTRATION

EUDRA-CT: 2015-004306-42; https://www.clinicaltrialsregister.eu/ctr-search/trial/2015-004306-42/SI , registered 17. 12. 2015.

Effects of Erythromycin on Osteoclasts and Bone Resorption via DEL-1 Induction in Mice

Macrolides are used to treat various infectious diseases, including periodontitis. Furthermore, macrolides are known to have immunomodulatory effects; however, the underlying mechanism of their action remains unclear. DEL-1 has emerged as an important factor in homeostatic immunity and osteoclastogenesis. Specifically, DEL-1 is downregulated in periodontitis tissues. Therefore, in the present study, we investigated whether the osteoclastogenesis inhibitory effects of erythromycin (ERM) are mediated through upregulation of DEL-1 expression. We used a ligature-induced periodontitis model in C57BL/6Ncrl wild-type or DEL-1-deficient mice and in vitro cell-based mechanistic studies to investigate how ERM inhibits alveolar bone resorption. As a result of measuring alveolar bone resorption and gene expression in the tooth ligation model, ERM treatment reduced bone loss by increasing DEL-1 expression and decreasing the expression of osteoclast-related factors in wild-type mice. In DEL-1-deficient mice, ERM failed to suppress bone loss and gene expression of osteoclast-related factors. In addition, ERM treatment downregulated osteoclast differentiation and calcium resorption in in vitro experiments with mouse bone marrow-derived macrophages. In conclusion, ERM promotes the induction of DEL-1 in periodontal tissue, which may regulate osteoclastogenesis and decrease inflammatory bone resorption. These findings suggest that ERM may exert immunomodulatory effects in a DEL-1-dependent manner.

The effect of coating chitosan on Porphyromonas gingivalis biofilm formation in the surface of orthodontic mini-implant

Infection is the main problem for the failure of orthodontic mini-implant. Modern prevention of infection is now focused on local antibacterial coatings on implant devices. Chitosan is biocompatible and has antibacterial properties. Azithromycin is a synthetic antibiotic with immunomodulatory properties in which it has an advantage over the rest of antibiotics. This study aimed to evaluate the effect coating chitosan on the orthodontic mini-implant in Porphyromonas gingivalis biofilm formation. This is an experimental study using 25 orthodontic mini-implants. Five samples were coated with chitosan, 5 samples were coated with chitosan-azithromycin, 5 samples were coated with azithromycin, 5 samples were uncoated, and 5 samples were uncoated and were not exposed to P. gingivalis. P. gingivalis biofilms on the surface of the orthodontic mini-implant were observed after 24 h of incubation. P. gingivalis biofilm mass inhibition was highest in the azithromycin-treated group, followed by chitosan + azithromycin and chitosan only. The one-way ANOVA statistic test and post hoc Bonferroni statistic test of P. gingivalis biofilm mass show a significant difference between and within groups of experiments (P < 0.05). The Pearson correlation test with a value of R = +0.88, indicated that the bacterial viability count and the biofilm mass have a strong positive correlation. In conclusion, orthodontic mini-implant coated with chitosan, chitosan with azithromycin, or azithromycin only effectively suppressed P. gingivalis biofilm formation.

Influence of adjunctive azithromycin on microbiological and clinical outcomes in periodontitis patients: 6-month results of randomized controlled clinical trial

BACKGROUND

Our aim was to determine if azithromycin therapy, as an adjunct to scaling and root planing (SRP), decreases the number of pathobiontic subgingival plaque species and sites demonstrating pocket depth (PD) ≥ 5 mm and bleeding on probing (BOP) 6 months post-treatment.

METHODS

In a double-blind randomized parallel-arm placebo-controlled trial, 40 patients received nonsurgical periodontal treatment in two sessions within 7 days. Patients then received systemic antibiotic therapy (n = 20, azithromycin 500 mg/day for 3 days) or placebo (n = 20). Pooled microbiologic samples were taken before and 6 months after therapy and analysed by established culture methods. The primary outcome variable was the number of sites with PD ≥ 5 mm and BOP at the 6-month re-evaluation. Using multivariate multilevel logistic regression, the effects of gender, age, antibiotic therapy, presence of P. gingivalis or A. actinomycetemcomitans, smoking, tooth being a molar and interdental location were evaluated.

RESULTS

The number of sites with PD ≥ 5 mm and BOP after 6 months was similar in the test (Me = 4, IQR = 0-11) and control (Me = 5, IQR = 1-22) group. Adjunctive azithromycin treatment, compared to SRP alone, resulted in more frequent eradication of A. actinomycetemcomitans (p = 0.013) and C. rectus (p = 0.029), decreased proportion (p = 0.006) and total counts (p = 0.003) of P. gingivalis, and decreased proportion of C. rectus (p = 0.012). Both groups showed substantial but equivalent improvements in periodontal parameters, with no intergroups differences at initially shallow or deep sites. The logistic regression showed a lower odds ratio for healing of diseased sites on molars (OR = 0.51; p <  0,001).

CONCLUSION

Despite significant changes in numbers of A. actinomycetemcomitans, P. gingivalis and C. rectus, patients with periodontitis do not benefit from adjunctive systemic azithromycin in terms of number of persisting sites with PD ≥ 5 mm and BOP.

TRIAL REGISTRATION

EUDRA-CT: 2015-004306-42; https://www.clinicaltrialsregister.eu/ctr-search/trial/2015-004306-42/SI , registered 17. 12. 2015.

The Use of Antimicrobial Photodynamic Therapy to Maintain a Hopeless Tooth With a PeriodonticEndodontic Lesion: A Case Report

Background: In spite of some advances in periodontal generative methods, it is impossible to stop progressive Loss of supporting alveolar bone in some end-stage periodontitis. The aim of this study is to report a kind of treatment modality which was seemed to be successes full in maintaining teeth. In this case-report, a hopeless tooth was saved by combined non-surgical periodontalendodontal treatment and antimicrobial photodynamic therapy (aPDT). Case Report: A 58-year-old male presented with a chief complaint of pain and mobility of tooth number 38. Clinical examinations revealed a periodontic-endodontic lesion with clinical attachment loss exceeding 10 mm and grade III mobility. To preserve the tooth, we operated nonsurgical periodontal treatment including scaling and root planning (SRP) plus root canal therapy (RCT) combined with intra-root canal non-aPDT laser decontamination. Then we applied laser pocket therapy with and without aPDT. Following 6 months of the aPDT treatment, the mobility and pocket depth of the tooth improved from grade III to I and from 10 to 3 millimeters respectively. Conclusion: aPDT is a novel adjunctive therapy that can be used for various conditions with microbial etiology. This case report demonstrated that aPDT might be effective in the treatment of periodontic-endodontic lesions in a hopeless tooth.

Antibiotics in Dentistry: A Narrative Review of Literature and Guidelines Considering Antibiotic Resistance

Background:

Antibiotic resistance is an important issue for public health.

Objective:

The aim of this work is to investigate the clinical situations which require the administration of antibiotics in dentistry.

Methods:

The authors want to do a review of the literature and a comparison of guidelines in dentistry among different countries. The research method was based on the use of Pubmed and the research of indexed articles and documents published by authorities and boards about the antibiotic prescription in dentistry. The paper is an analysis deep inside the physiological and pathological situations that, according to different guidelines, require the use of antimicrobics. The spirit is a clinical one because this paper wants to be a guide for dentists, especially before the administration, in order to moderate the use of antimicrobials. We must remember that the World Health Organisation organizes each year the World Antibiotic Awareness Week, in order to fight against the improper administration of antibiotics in medicine, dentistry, veterinary medicine, and industrial livestock.

Results:

Different guidelines converge on a very calibrate and proper administration of antibiotics. Antibiotics should be used only in recommended situations for risk patients. The authorities and boards should investigate the habits of antibiotic administration, which according to some papers seem to be large and diffused use, not only limited to situations described in guidelines.

Conclusion:

Dentists, together with the General Practitioners and Paediatricians, should be cautious and accurate and should administrate antibiotics only if recommended by guidelines and effective and safe.

Disease severity, debridement approach and timing of drug modify outcomes of adjunctive azithromycin in non-surgical management of chronic periodontitis: a multivariate meta-analysis

Background

Past meta-analyses have shown adjunctive systemic Azithromycin (AZI) to provide minor clinical benefits in scaling and root surface debridement (S/RSD). However, these have not considered the covariance of key outcome parameters; probing pocket depth (PPD) and Clinical Attachment Level (CAL) or systematically examined some potential sources of heterogeneity.

Aim

To jointly synthesize 6-month outcomes of systemic AZI as adjunctive to S/RSD in chronic periodontitis and investigate 3 potential sources of heterogeneity.

Methods

Four databases were searched for suitable randomized controlled clinical trials (RCTs). Standardized mean differences (SMD) in PPD and CAL between AZI + S/RSD and S/RSD alone, at 6-month follow-up were computed. Within-study covariances of PPD and CAL were derived from reported multiple time-point data. A multivariate meta-analysis with random effects jointly modelled PPD and CAL, factoring in their covariance. This model included 3 moderators with interaction effects; timing of AZI initiation (pre-therapy/post-therapy), type of S/RSD [full-mouth debridement (FMD)/partial-mouth debridement (PMD)], and baseline study-level mean values of PPD/CAL.

Results

Among 276 abstracts, 11 observations from 9 RCTs qualified for meta-analysis. Within-study correlation-coefficients of PPD with CAL significantly increased with increasing study-level baseline mean values (Spearman’s r = 0.79, p < 0.01). The full multivariate meta-analysis model showed significant effects for the 3 moderators (Q statistic = 150.03, p < 0.01), retained significant residual heterogeneity (Q statistic = 88.50, p < 0.01) but outperformed (Likelihood- ratio statistic = 102.95, p < 0.01,) a null-model with no moderators (Q statistic = 201.5, p < 0.01). A significant effect was seen only on the SMD for PPD (estimate = 1.16 mm, 95% CI: 0.27 mm–2.07 mm mm, p = 0.01) but not CAL (estimate = 0.17 mm, 95% CI: -0.92 mm-1.26 mm, p = 0.76). SMD in PPD positively interacted with study baseline value (estimate = 0.11, 95% CI: 0.08–0.15, p < 0.01). Significant negative interactions of SMD in PPD with PMD (estimate = − 1.25 mm, 95% CI: -1.73 mm- -0.78 mm, p < 0.01) and pre-therapy drug initiation (estimate = − 1.18 mm, 95% CI: -1.48 mm--0.87 mm, p < 0.01) were evident.

Conclusion

Joint synthesis of PPD and CAL showed, at 6-months, AZI + S/RSD provided a benefit over S/RSD alone for PPD alone when correlation with CAL was accounted for. Deeper study-level baseline PPD, FMD type of S/RSD, and post-therapy drug initiation associated with greater PPD reduction.

Electronic supplementary material

The online version of this article (10.1186/s12903-019-0754-0) contains supplementary material, which is available to authorized users.

Azithromycin and erythromycin susceptibility and macrolide resistance genes in Prevotella from patients with periodontal disease

OBJECTIVES

To study oral Prevotella spp. isolated from patients with chronic periodontitis, to determine their susceptibility to azithromycin and erythromycin and to screen the presence of macrolide resistance genes therein.

MATERIAL AND METHODS

Isolates with a Prevotella-like morphology were obtained from subgingival samples of 52 patients with chronic periodontitis. Each isolate was identified to the species level by sequencing of the 16S rRNA gene. In 100 Prevotella spp. isolates, azithromycin and erythromycin susceptibility was determined using the E test method, and the screening of erm(A), erm(B), erm(C), erm(F), erm(G), erm(Q) and mef(A) genes was done by PCR.

RESULTS

Prevotella intermedia and Prevotella nigrescens were the most identified species (33% each). Minimum inhibitory concentrations (MICs) ranges for both antibiotics were 0.016/0.032 to >256 μg/ml. MIC₅₀ values for azithromycin and erythromycin were 1.5 and 1 μg/ml, respectively, and MIC₉₀ values were >256 μg/ml for both antibiotics. Nineteen per cent of the isolates carried erm(B), and 51% carried erm(F).

CONCLUSIONS

The MIC values found were high compared to previous studies. erm(F) was greatly prevalent, and we describe for the first time the erm(B) gene in Prevotella spp. The presence of either of the genes seems to be associated with a higher degree of resistance to azithromycin and erythromycin.

Optimal design of thiostrepton-derived thiopeptide antibiotics and their potential application against oral pathogens

A new fluorinated thiostrepton-type thiopeptide antibiotic was designed and biosynthesized by using a biological approach with synthetic advantages. Related bioassays indicated that thiostrepton and its derivatives hold potential in oral pathogen treatment.