Should Antibiotics Be Prescribed to Treat Chronic Periodontitis?

Icariin suppresses osteogenic differentiation and promotes bone regeneration in Porphyromonas gingivalis-infected conditions through EphA2-RhoA signaling pathway

Periodontitis is associated with multiple systemic diseases and can cause bone loss. Porphyromonas gingivalis (P. gingivalis) is one of the most virulent periodontal pathogens. Icariin is a flavonoid extracted from the traditional Chinese herbal medicine Herba Epimedii, and can regulate bone metabolism. However, its effects on promoting bone metabolism have not been fully elucidated. In this experiment, we infected MC3T3-E1 cells with P. gingivalis. Flow cytometry results show that persistent bacterial infection does not affect cell proliferative activity. Western blotting, ALP activity detection, mineral content determination, and immunofluorescence blotting confirmed that icariin improved osteogenic differentiation in the inflammatory state, and this effect may be more obvious in the early stage of osteogenic differentiation. The antibacterial assays, ROS and MMP fluorescence assays demonstrated that icariin exerted a significant inhibitory effect on bacterial growth and attenuated the inflammatory response in bacterial-infected conditions. The results of in vivo experiments in animals further validated the excellent properties exerted by icariin in the repair of bone defects. Additionally, in the P. gingivalis-infected state, icariin exert a regulatory effect on EphA2-RhoA signaling pathway to augment osteogenic differentiation. These exciting findings suggest that icariin holds significant potential for therapeutic application in the management of periodontal bone loss.

Control of tissue homeostasis by the extracellular matrix: Synthetic heparan sulfate as a promising therapeutic for periodontal health and bone regeneration

Proteoglycans are core proteins associated with carbohydrate/sugar moieties that are highly variable in disaccharide composition, which dictates their function. These carbohydrates are named glycosaminoglycans, and they can be attached to proteoglycans or found free in tissues or on cell surfaces. Glycosaminoglycans such as hyaluronan, chondroitin sulfate, dermatan sulfate, keratan sulfate, and heparin/heparan sulfate have multiple functions including involvement in inflammation, immunity and connective tissue structure, and integrity. Heparan sulfate is a highly sulfated polysaccharide that is abundant in the periodontium including alveolar bone. Recent evidence supports the contention that heparan sulfate is an important player in modulating interactions between damage associated molecular patterns and inflammatory receptors expressed by various cell types. The structure of heparan sulfate is reported to dictate its function, thus, the utilization of a homogenous and structurally defined heparan sulfate polysaccharide for modulation of cell function offers therapeutic potential. Recently, a chemoenzymatic approach was developed to allow production of many structurally defined heparan sulfate carbohydrates. These oligosaccharides have been studied in various pathological inflammatory conditions to better understand their function and their potential application in promoting tissue homeostasis. We have observed that specific size and sulfation patterns can modulate inflammation and promote tissue maintenance including an anabolic effect in alveolar bone. Thus, new evidence provides a strong impetus to explore heparan sulfate as a potential novel therapeutic agent to treat periodontitis, support alveolar bone maintenance, and promote bone formation.

Emergence of Antibiotic-Resistant Porphyromonas gingivalis in United States Periodontitis Patients

Antibiotic resistance patterns of the major human periodontal pathogen Porphyromonas gingivalis were assessed over a 20-year period in the United States. Subgingival P. gingivalis was cultured pre-treatment from 2193 severe periodontitis patients during three time periods: 1999-2000 (936 patients), 2009-2010 (685 patients), and 2019-2020 (572 patients). The clinical isolates were tested for in vitro resistance to 4 mg/L for clindamycin and doxycycline, 8 mg/L for amoxicillin, and 16 mg/L for metronidazole, with a post hoc combination of data for metronidazole plus amoxicillin. Clindamycin-resistant P. gingivalis was significantly more prevalent in 2009-2010 (9.1% of patients) and 2019-2020 (9.3%; 15-fold increase) as compared to 1999-2000 (0.6%). P. gingivalis resistance to amoxicillin also significantly increased from 0.1% of patients in 1999-2000 to 1.3% in 2009-2010 and 2.8% (28-fold increase) in 2019-2020. P. gingivalis resistance to metronidazole, metronidazole plus amoxicillin, and doxycycline was low (≤0.5% prevalence), and statistically unchanged, over the 20-year period. These findings are the first to reveal marked increases over 20 years in clindamycin-resistant and amoxicillin-resistant P. gingivalis in United States periodontitis patients. Increased antibiotic resistance of P. gingivalis and other periodontitis-associated bacteria threatens the efficacy of periodontal antimicrobial chemotherapy.

Bestatin as a treatment modality in experimental periodontitis

BACKGROUND

Chronic periodontitis (CP), the most prevalent dysbiotic bacteria-driven chronic inflammatory disease, is an underestimated global health problem in itself, and due to a causative relationship with other disorders such as cardiovascular diseases or Alzheimer disease. The CP pathogenesis is primarily driven by Porphyromonas gingivalis in humans, and Porphyromonas gulae in dogs. These microorganisms initiate a pathogenic shift in the composition of the tooth-surface microflora. Our objective was to evaluate antimicrobial effects of bestatin, a potential CP drug candidate.

METHODS

We evaluated bestatin bacteriostatic efficiency against periodontopathogens in planktonic cultures via microplate assay, and mono- and multispecies oral biofilm models. Neutrophil bactericidal activities, such as phagocytosis, were investigated in vitro using granulocytes isolated from the peripheral blood. The therapeutic efficacy and the immunomodulatory function of bestatin was assessed in a murine model of CP.

RESULTS

Bestatin exhibited bacteriostatic activity against both P. gingivalis and P. gulae, and controlled the formation and species composition of the biofilm. We demonstrated that bestatin promotes the phagocytosis of periodontopathogens by neutrophils. Finally, we found that providing bestatin in the animal feed prevented alveolar bone resorption.

CONCLUSIONS

We show that in a murine model of CP bestatin not only shifted the biofilm species composition from pathogenic to a commensal one, but also promoted bacteria clearance by immune cells and alleviated inflammation. Taken together, these results suggest that bestatin is a promising drug choice for the treatment and/or prevention of periodontitis and clinical trials are required to fully evaluate its potency.

Treatment of Periodontitis Affecting Human Primary Teeth-A Systematic Review

The aim of this systematic review is to report the treatment options (Intervention) and outcomes (O) for primary teeth affected by periodontitis (Population) and if the treatment of primary teeth can prevent the spread of periodontitis to permanent teeth (Outcomes). The following databases were searched for papers published before December 2022: PubMed, Embase, Web of Science, and Ebscohost. Studies on children affected by periodontitis involving the primary teeth were included and those on children who presented with periodontitis as a manifestation of systemic disease were excluded. Narrative synthesis and methodological quality assessments were performed for the included studies. Three interventional studies (without a control group) that evaluated treatments involving scaling and root planing (SRP with antibiotics) and extraction were included (total n = 60 patients). Additionally, twelve case reports/case series articles (n = 19 patients) were identified. The diagnoses ranged from aggressive periodontitis to juvenile periodontitis and pre-pubertal periodontitis. Based on a limited number of published studies, it was found that the early treatment of periodontitis affecting the primary teeth using SRP and systemic antibiotics resulted in favorable improvements in PD and CAL. Limited evidence suggests that SRP and the extraction of the primary teeth involved have the potential to prevent periodontitis affecting permanent teeth. Future trials are required to standardize the treatment protocols and to confirm these findings.

Beneficial Effects of Melatonin on Periodontitis Management: Far More Than Oral Cavity

Periodontitis as a highly prevalent chronic infection/inflammatory disease can eventually lead to tooth loss and masticatory dysfunction. It also has a negative impact on general health and largely impairs quality of life. The tissue destruction during periodontitis is mainly caused by the excessive immune-inflammatory response; hence, how to modulate the host's reaction is of profound importance for effective periodontal treatment and tissue protection. Melatonin, as an endogenous hormone exhibiting multiple biological functions such as circadian rhythm regulation, antioxidant, and anti-inflammation, has been widely used in general healthcare. Notably, the past few years have witnessed increasing evidence for the application of melatonin as an adjunctive approach in the treatment of periodontitis and periodontitis-related systemic comorbidities. The detailed underlying mechanisms and more verification from clinical practice are still lacking, however, and further investigations are highly required. Importantly, it is essential to establish standard guidelines in the near future for the clinical administration of melatonin for periodontal health and general wellbeing.

Antibiotic prescription patterns among US general dentists and periodontists

BACKGROUND

In the absence of a full spectrum of evidence-based guidelines for the appropriate use of antimicrobial agents, dentists, including periodontists, remain a highly frequent antibiotic prescribing group. With the goal of understanding antibiotic prescribing practices, the authors surveyed a convenience sample of dental practitioners and periodontists to identify differences between the 2 cohorts and assess the factors that affect prescribing practices.

METHODS

An institutional review board-approved 15-item survey was developed to capture antibiotic prescribing practices addressing the main research question, factors affecting systemic antibiotic prescription patterns, and prescription timing. The authors collaborated with the American Dental Association (ADA) and the American Academy of Periodontology (AAP) for survey dissemination. Responses were summarized using descriptive statistics. Multivariable models were developed to identify antibiotic prescription predictors.

RESULTS

Overall, 32.4% of the participants prescribed systemic antibiotics with scaling and root planing. When comparing the 2 groups, the authors found that 46.4% and 18.7% of the AAP and ADA members, respectively, prescribed systemic antibiotics with scaling and root planing (P = .0001). The authors found a significant difference between the AAP and ADA groups in prescription timing (P = .01). The multivariable model revealed that practitioner sex (P = .03), AAP membership (P = .0001), and years of practitioner experience (P = .04) predicted antibiotic prescription practices. The geographic location, practice setting, and occupation type did not predict antibiotic prescription patterns.

CONCLUSION

The authors found a lack of clarity related to prescription timing, factors determining prescription patterns, and selection of patient population who would benefit more from antibiotics.

PRACTICAL IMPLICATIONS

This study confirmed a lack of clarity related to antibiotic prescription patterns in combination with nonsurgical periodontal treatment.

The Expression of miR-34a in Gingival Crevicular Fluid of Chronic Periodontitis and Its Connection with the TLR/NF-κB Signaling Pathway

Objective

This study analyzed the expression of miR-34a in gingival crevicular fluid (GCF) of patients with chronic periodontitis and its connection with the Toll-like receptor (TLR)/nuclear factor kappa-B (NF-κB) signaling pathway.

Methods

We collected the GCF of the two groups of subjects, using RT-PCR to detect the expression of miR-34a and NF-κB p65 mRNA and TLR4 mRNA and ELISA to detect the inflammatory factor degree in GCF, and performed periodontal examinations on both groups.

Results

The gingival index, bleeding index, probe depth, and attachment loss indexes of periodontal examination in the observation group were remarkably superior to those in the control group (P < 0.05). The levels of IL-1β, IL-6, and TNF-α in the GCF of the observation group were higher than those of the control group (P < 0.05). The mRNA relative expression levels of miR-34a, NF-κB p65, and TLR4 in the GCF of the observation group were dramatically higher than those of the control group (P < 0.05). Correlation analysis showed that miR-34a was highly expressed in patients with chronic periodontitis.

Conclusion

There is an abnormally high expression of miR-34a in GCF of chronic periodontitis. Its expression is associated with the degree of periodontal inflammation, periodontal tissue damage, and the activation of the TLR/NF-κB signaling pathway and could be used as a potential index for auxiliary diagnosis and severity of the disease.

An in vitro model for studies of attenuation of antibiotic-inhibited growth of Aggregatibacter actinomycetemcomitans Y4 by polyamines

Polyamines are ubiquitous polycationic molecules that are present in all prokaryotic and eukaryotic cells, and they serve as important modulators of cell growth, stress, and cell proliferation. Polyamines are present at high concentrations in the periodontal pocket and could potentially affect the stress response of periodontal bacteria to antibiotics. The effects of polyamines on inhibition of growth by amoxicillin (AMX), azithromycin (AZM), and doxycycline (DOX) were investigated with the Y4 strain of Aggregatibacter actinomycetemcomitans (Aa). Bacteria were grown in brain heart infusion broth under the following conditions: (1) Aa only, (2) Aa + polyamine mix (1 mM putrescine, 0.4 mM spermidine, and 0.4 mM spermine), (3) Aa + antibiotic, and (4) Aa + antibiotic + polyamines. Growth curve analysis, minimal inhibitory concentration determination, and transcriptomic studies were conducted. The presence of exogenous polyamines produced a small, but significant increase in Aa growth, and polyamines attenuated the inhibitory effects of AMX, AZM, and DOX on growth. Transcriptomic analysis revealed that polyamines upregulate expression of ribosomal biogenesis proteins and small subunits, attenuate the bacterial stress response to antibiotics, and modulate bacterial nutritional pathways in a manner that could potentially increase the virulence of Aa. In summary, the polyamine‐rich environment found in periodontal pockets appears to protect Aa and reduce its susceptibility to several antimicrobial agents in this in vitro model.

Insight into the roles of melatonin in bone tissue and bone‑related diseases (Review)

Bone‑related diseases comprise a large group of common diseases, including fractures, osteoporosis and osteoarthritis (OA), which affect a large number of individuals, particularly the elderly. The progressive destruction and loss of alveolar bone caused by periodontitis is a specific type of bone loss, which has a high incidence and markedly reduces the quality of life of patients. With the existing methods of prevention and treatment, the incidence and mortality of bone‑related diseases are still gradually increasing, creating a significant financial burden to societies worldwide. To prevent the occurrence of bone‑related diseases, delay their progression or reverse the injuries they cause, new alternative or complementary treatments need to be developed. Melatonin exerts numerous physiological effects, including inducing anti‑inflammatory and antioxidative functions, resetting circadian rhythms and promoting wound healing and tissue regeneration. Melatonin also participates in the health management of bone and cartilage. In the present review, the potential roles of melatonin in the pathogenesis and progression of bone injury, osteoporosis, OA and periodontitis are summarized. Furthermore, the high efficiency and diversity of the physiological regulatory effects of melatonin are highlighted and the potential benefits of the use of melatonin for the clinical prevention and treatment of bone‑related diseases are discussed.

Effect of Hydrogen Peroxide Photoactivated Decontamination Using 940 nm Diode Laser in Periodontal Treatment: A Pilot Study

Objective: The aim of this study was to compare the antimicrobial effects of hydroxyl radical generation by photoactivation of hydrogen peroxide (H₂O₂) with diode laser (λ = 940 nm) in combination with conventional nonsurgical periodontal therapy. Materials and methods: Thirty-eight patients and 114 teeth were included in this study. The test teeth were randomly assigned to one of the three treatment groups: Group 1 (control group): scaling and root planning (SRP); and the following experimental groups: Group 2: SRP +940 nm diode laser; Group 3: SRP+photoactivation of H₂O₂ with 940 nm diode laser. Clinical examinations, such as periodontal probing depth (PPD), clinical attachment level (CAL), and bleeding on probing (BoP) were performed before and after the treatment. The microbiological evaluation included nine periodontal bacterial species investigated by means of real-time polymerase chain reaction assay before and after the treatment. The clinical and bacterial differences were assessed between the investigated groups. Results: The total bacteria load was reduced for all three studied groups and all periodontal indexes (PPD, CAL, and BoP) were improved after each treatment. Group 3 showed significant bacterial reduction of the major periodontal bacteria such as Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, Peptostreptococcus micros, Fusobacterium nucleatum, Eubacterium nodatum (p < 0.001) in contrast to the other two groups (p > 0.001). Differences between tested groups showed significant results with regard to Group 3. Conclusions: The synergistic effect of SRP and photoactivation of H₂O₂ with 940 nm diode laser offers an efficient and reliable antimicrobial effect in the nonsurgical periodontal treatment approach.

Inhibition of neutrophil inflammatory mediator expression by azithromycin

BACKGROUND AND OBJECTIVE

Peri-implant tissues appear to exhibit a more vigorous inflammatory response during post-operative healing than periodontal tissues. There is evidence that a single dose of amoxicillin (AMX) prior to implant surgery reduces the risk of early peri-implant healing complications. This study compared the effects of AZM and AMX on neutrophil expression of mRNA for mediators involved in peri-implant healing.

MATERIALS AND METHODS

Neutrophils were isolated from healthy human donors and pre-incubated with AZM (4 or 8 μg/ml) or AMX (2 or 4 μg/ml). Cells were then incubated with LPS (1 μg/ml), TNF-α (10 ng/ml), or medium alone (control) for 1, 2, and 4 h. Total RNA was analyzed with qPCR to quantify changes in expression of the six inflammatory mediators.

RESULTS

LPS and TNF-α induced a similar pattern of IL-1β mRNA expression, with peak expression at 1 h. For most mediators, gene expression in neutrophils activated by LPS was markedly reduced in a dose-dependent manner by AZM. Therapeutic concentrations of AZM (8 μg/ml) consistently reduced expression of mediators tested in this study. AMX was effective only in a few cases and under certain conditions. Therefore, AZM was more effective in its direct anti-inflammatory action.

CONCLUSION

AZM is a consistent and effective inhibitor of neutrophil inflammatory mediator mRNA expression.

CLINICAL RELEVANCE

Given that a single dose of AZM produces higher and more sustained concentrations of this agent in periodontal tissues than AMX when used as a pre-operative prophylactic antibiotic, AZM has greater potential to inhibit inflammatory mediator expression at peri-implant wound sites than AMX.

TRPV4 is a regulator in P. gingivalis lipopolysaccharide-induced exacerbation of macrophage foam cell formation

Porphyromonas gingivalis (P.g), a major causative agent of periodontitis, has been linked to atherosclerosis, a chronic inflammatory vascular disease. Recent studies have suggested a link between periodontitis and arterial stiffness, a risk factor for atherosclerosis. However, the mechanisms by which P.g infection contributes to atherogenesis remain elusive. The formation of lipid-laden macrophage "foam cells" is critically important to development and progression of atherosclerosis. We have obtained evidence that TRPV4 (transient receptor potential channel of the vanilloid subfamily 4), a mechanosensitive channel, is a regulator of macrophage foam cell formation both in response to P.g-derived lipopolysaccharide (PgLPS) or to an increase in matrix stiffness. Importantly, we found that TRPV4 activity (Ca²⁺ influx) was increased in response to PgLPS. Genetic deletion or chemical antagonism of TRPV4 channels blocked PgLPS-triggered exacerbation of oxidized LDL (oxLDL)-mediated foam cell formation. Mechanistically, we found that (1) TRPV4 regulated oxLDL uptake but not its cell surface binding in macrophages; (2) reduced foam cell formation in TRPV4 null cells was independent of expression of CD36, a predominant receptor for oxLDL, and (3) co-localization of TRPV4 and CD36 on the macrophage plasma membrane was sensitive to the increased level of matrix stiffness occurring in the presence of PgLPS. Altogether, our results suggest that TRPV4 channels play an essential role in P.g-induced exacerbation of macrophage foam cell generation through a mechanism that modulates uptake of oxLDL.

Comparative In Vitro Resistance of Human Periodontal Bacterial Pathogens to Tinidazole and Four Other Antibiotics

The in vitro resistance of selected red/orange complex periodontal pathogens to tinidazole was compared with four other antibiotics. Subgingival biofilm samples from 88 adults with severe periodontitis were anaerobically incubated on enriched Brucella blood agar with and without supplementation with tinidazole (16 mg/L), metronidazole (16 mg/L), amoxicillin (8 mg/L), doxycycline (4 mg/L), or clindamycin (4 mg/L). Growth of Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia/nigrescens, Parvimonas micra, Fusobacterium nucleatum, Streptococcus constellatus, or Campylobacter rectus on antibiotic-supplemented plates indicated their in vitro antibiotic resistance. Tinidazole inhibited all test species, except P. intermedia/nigrescens, P. micra, and S. constellatus in 3.8%, 10.2%, and 88.9% of species-positive patients, respectively. Significantly fewer patients yielded tinidazole-resistant test species, and had significantly lower subgingival proportions of tinidazole-resistant organisms, than patients with amoxicillin, doxycycline, or clindamycin-resistant species, but not those with metronidazole-resistant strains. Joint in vitro species resistance to tinidazole and amoxicillin, or metronidazole and amoxicillin, was rare. Tinidazole performed in vitro similar to metronidazole, and markedly better than amoxicillin, doxycycline, or clindamycin, against fresh clinical isolates of red/orange complex periodontal pathogens. As a result of its similar antimicrobial spectrum, and more convenient once-a-day oral dosing, tinidazole should be considered in place of metronidazole for systemic periodontitis drug therapy.

Managing knowledge for health care quality: An investigation of rational antibiotic use among Thai dentists

OBJECTIVES

Because of the irrational use of antibiotics, antimicrobial resistance is now a global concern that requires developing effective strategies against. The aim of this study was to assess the knowledge gap that causes the irrational use of antibiotics among Thai dentists.

METHODS

Thai dentists were asked to complete an online questionnaire regarding their knowledge, perception, and attitude towards rationale antibiotic use. The survey was conducted during November to December 2018.

RESULTS

Online questionnaires were completed by 588 dentists. Most respondents had a positive perception and were aware of the rational use of antibiotics. However, the use of antibiotics without proper indication and the lack of pharmacological knowledge were found. A mobile application was considered the most preferable approach to manage knowledge for rational drug use.

CONCLUSION

Irrational drug use among Thai dentists can be caused by lack of knowledge, attitude, and the perception of each dentist. Policy makers should promote self-learning through knowledge management strategies that can complement the pharmacology courses taught in dental school.

Is the Use of Antimicrobial Photodynamic Therapy or Systemic Antibiotics More Effective in Improving Periodontal Health When Used in Conjunction with Localised Non-Surgical Periodontal Therapy? A Systematic Review

Periodontal disease can be treated in several ways. This paper reviewed whether antimicrobial photodynamic therapy (aPDT) in addition to scaling and root planing (SRP) produces improved clinical results over systemic antibiotics (ABs) in conjunction with SRP in adults with periodontitis. Studies were searched using the following electronic databases: MEDLINE, the Cochrane Database of Systematic Reviews, and the Web of Science Core Collection up to and including November 2018. Four randomized controlled trials (RCTs) were reviewed to maximise the reliability of the evidence. All participants suffered from either chronic or aggressive periodontitis and each study contained SRP as an adjunct to ABs or aPDT. To determine whether groups showed improvement after treatment, the outcome parameters chosen were probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP). Despite finding significant improvements in all groups, the differences among groups were not consistently statistically significant. The lack of homogeneity in the results among these studies indicates that it was not possible to determine a conclusion about whether aPDT or AB as an adjunct to SRP provides better improvements in periodontitis as measured by PD, CAL, and BOP. Further studies with more similar study designs are required before firm conclusions can be deduced.

Characterization and development of SAPP as a specific peptidic inhibitor that targets Porphyromonas gingivalis

Porphyromonas gingivalis is a keystone bacterium in the oral microbial communities that elicits a dysbiosis between the microbiota and the host. Therefore, inhibition of this organism in dental plaques has been one of the strategies for preventing and treating chronic periodontitis. We previously identified a Streptococcal ArcA derived Anti-P gingivalils Peptide (SAPP) that in vitro, is capable of repressing the expression of several virulence genes in the organism. This leads to a significant reduction in P gingivalis virulence potential, including its ability to colonize on the surface of Streptococcus gordonii, to invade human oral epithelial cells, and to produce gingipains. In this study, we showed that SAPP had minimal cytotoxicity to human oral keratinocytes and gingival fibroblasts. We observed that SAPP directly bound to the cell surface of P gingivalis, and that alterations in the sequence at the N-terminus of SAPP diminished its abilities to interact with P gingivalis cells and repressed the expression of virulence genes. Most strikingly, we demonstrated using an ex-vivo assay that besides its inhibitory activity against P gingivalis colonization, SAPP could also reduce the levels of several other oral Gram-negative bacteria strongly associated with periodontitis in multispecies biofilms. Our results provide a platform for the development of SAPP-targeted therapeutics against chronic periodontitis.

Laser reduction of specific microorganisms in the periodontal pocket using Er:YAG and Nd:YAG lasers: a randomized controlled clinical study

The objective of this study was to evaluate the microbiological and clinical outcomes following nonsurgical treatment by either scaling and root planing, combination of Nd:YAG and Er:YAG lasers, or by Er:YAG laser treatment alone. The study involved 60 patients with generalized chronic periodontitis, randomly assigned into one of three treatment groups of 20 patients. The first group received scaling and root planing by hand instruments (SRP group), the second group received Er:YAG laser treatment alone (Er group), and the third group received combined treatment with Nd:YAG and Er:YAG lasers (NdErNd group). Microbiological samples, taken from the periodontal pockets at baseline and 6 months after treatments, were assessed with PET Plus tests. The combined NdErNd laser (93.0%), followed closely by Er:YAG laser (84.9%), treatment resulted in the highest reduction of all bacteria count after 6 months, whereas SRP (46.2%) failed to reduce Treponema denticola, Peptostreptococcus micros, and Capnocytophaga gingivalis. Full-mouth plaque and bleeding on probing scores dropped after 6 months and were the lowest in both laser groups. The combination of NdErNd resulted in higher probing pocket depth reduction and gain of clinical attachment level (1.99 ± 0.23 mm) compared to SRP (0.86 ± 0.13 mm) or Er:YAG laser alone (0.93 ± 0.20 mm) in 4-6 mm-deep pockets. Within their limits, the present results provide support for the combination of Nd:YAG and Er:YAG lasers to additionally improve the microbiological and clinical outcomes of nonsurgical periodontal therapy in patients with moderate to severe chronic periodontitis.

Evaluating the effectiveness of clarithromycin as an adjunct to scaling and root planing: A randomized clinical trial

Background

Administration of systemic antibiotics may implement persuasive treatment effect for chronic periodontitis by intending tissue-invasive bacteria in addition to accustomed nonsurgical periodontal therapy (NSPT).

Aims

The aim of this study was to assess the ancillary effects of oral clarithromycin (CLM) along with NSPT for chronic periodontitis.

Materials and Methods

Thirty periodontitis patients were randomly divided into two equal groups in this double-blind, randomized, parallel group, and active-controlled trial: test group - scaling and root planning (SRP) plus CLM (500 mg thrice daily for 7 days, orally) was given, and control group - only SRP was done. Clinical analysis, such as gingival index (GI), probing depth (PD), and clinical attachment loss (CAL), were taken at baseline, 3 months, and 6-month intervals for both groups. Subgingival plaque samples were cultured for periodontopathic organisms. Immunological parameter C-reactive protein (CRP) levels were estimated.

Results

SPSS version 14 was used for statistical analysis. The intragroup comparison showed a significant reduction in the mean scores of all the parameters from baseline to 6 months. The intergroup comparison showed a statistically significant reduction of PD from baseline to 3 months (P < 0.001). GI, CAL, and CRP levels were also reduced but not statistically significant. The mean colony-forming units (CFU) of Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) showed a statistically significant reduction from baseline to 3 months only in the test group (P = 0.042) and (P = 0.046), respectively. There was no statistically significant reduction of Aa and Pg at 6 months.

Conclusions

CLM conceivably accepted as an addendum to NSPT for a shorter period.

A novel peptidic inhibitor derived from Streptococcus cristatus ArcA attenuates virulence potential of Porphyromonas gingivalis

Periodontitis is a global health problem and the 6th most common infectious disease worldwide. Porphyromonas gingivalis is considered a keystone pathogen in the disease and is capable of elevating the virulence potential of the periodontal microbial community. Strategies that interfere with P. gingivalis colonization and expression of virulence factor are therefore attractive approaches for preventing and treating periodontitis. We have previously reported that an 11-mer peptide (SAPP) derived from Streptococcus cristatus arginine deiminase (ArcA) was able to repress the expression and production of several well-known P. gingivalis virulence factors including fimbrial proteins and gingipains. Herein we expand and develop these studies to ascertain the impact of this peptide on phenotypic properties of P. gingivalis related to virulence potential. We found that growth rate was not altered by exposure of P. gingivalis to SAPP, while monospecies and heterotypic biofilm formation, and invasion of oral epithelial cells were inhibited. Additionally, SAPP was able to impinge the ability of P. gingivalis to dysregulate innate immunity by repressing gingipain-associated degradation of interleukin-8 (IL8). Hence, SAPP has characteristics that could be exploited for the manipulation of P. gingivalis levels in oral communities and preventing realization of virulence potential.