Microbial etiological agents of destructive periodontal diseases

Local promotion of B10 function alleviates experimental periodontitis bone loss through antagonizing RANKL-expressing neutrophils

BACKGROUND

Persistent host immune responses initiated by oral bacteria protect host against infection but may also elicit the process of sustained periodontal inflammation and subsequent alveolar bone loss. Interleukin-10 (IL-10), an anti-inflammatory cytokine, can downregulate pro-inflammatory cytokine and inhibit neutrophil migration in inflammation. IL-10-expressing regulatory B cells (B10) is termed by negatively regulating immune response through IL-10 and are mainly restricted in CD19⁺ CD1d^hi CD5⁺ B cells in mice. Our current study was aimed to explore the effect of locally transferred CD19⁺ CD1d^hi CD5⁺ B cells on inflammation and alveolar bone loss in an experimental periodontitis mouse model.

METHODS

Ligation plus P. gingivalis (Pg) infection was used to induce periodontitis in a mouse model. CD19⁺ CD1d^hi CD5⁺ B cells were sorted by flow cytometry and transferred into the gingivae immediately on the fifth day after ligation. All the mice were sacrificed on day 14 after ligation.

RESULTS

H&E staining showed that inflammatory cell infiltration was significantly reduced by the CD19⁺ CD1d^hi CD5⁺ B cells. Toluidine blue staining showed that the CD19⁺ CD1d^hi CD5⁺ B cells alleviated alveolar bone loss in the ligature/Pg-induced periodontitis in mice. Immunohistochemical staining showed Receptor Activator of NF-KappaB Ligand (RANKL), Interleukin-1β(IL-1β) and Interleukin-17 (IL-17) were decreased after the CD19⁺ CD1d^hi CD5⁺ B cell transfer. Immunofluorescent staining showed that IL-10 was increased while the number of Ly6G⁺ neutrophil and its RANKL production were decreased in gingival tissue.

CONCLUSIONS

These results indicated that locally transferred CD19⁺ CD1d^hi CD5⁺ B cells may alleviate alveolar bone loss through inhibiting pro-inflammatory cytokine expression and RANKL-expressing neutrophils in the periodontitis mouse model.

Microbiota and cardiovascular disease risk: A scoping review

An increasing number of studies suggests that the oral and the intestinal microbiota may indirectly or directly influence cardiovascular risk. In this regard, the microbiota could act by modifying compounds naturally present in food, both in a potentially atherogenic sense and in a protective sense; on the other hand, specific bacterial strains whose growth could also be facilitated by compounds of alimentary origin, i.e. prebiotics could instead play direct effects on atherogenesis. In other words, the microbiota-food relationship is a bi-directional one in which the latter modifies the former that, in return, produces metabolites with healthful or noxious effects. In this scoping review, we examine some of the microbiota-cardiovascular risk interactions that, in light of the available evidence, can be considered to already enjoy convincing scientific solidity. Notably, we focus on the oral and intestinal microbiota, where research is most active, and we propose some future cardio-preventive opportunities: one would be to develop and test compounds that can inhibit the formation of microbiota-derived noxious molecules. After the development of appropriate, reliable, and inexpensive screening tools for metabotypes, personalized diets can be implemented and pertinent supplements could be prescribed. The other therapeutic and preventive route that could be traveled is that of microbiota modification, via the use of appropriate pro- and prebiotics.

Argeloside I inhibits the pathogenicity of Porphyromonas gingivalis TDC60

Porphyromonas gingivalis, a major pathogen associated with chronic periodontitis, produces several virulence agents in the outer cell membrane, including gingipains and hemagglutinins. These virulence factors enable the bacteria to adhere to periodontal tissue and degrade host proteins to obtain the nutrients needed for dental plaque formation. P. gingivalis TDC60 was recently identified as the most aggressive P. gingivalis strain to dates. In this study, we isolated a known pregnane glycoside, argeloside I, from the aqueous extract of Solenostemma argel leaves. Argeloside I completely hindered the growth of P. gingivalis TDC60 and inhibited the production of hemagglutinins as well as Arg- and Lys-specific gingipains. Our results demonstrate a new function of pregnane glycosides. Argeloside I may be a candidate for reducing the risk associated with P. gingivalis TDC60 and its adhesion factors.

A Dual Zinc plus Arginine formulation attenuates the pathogenic properties of Porphyromonas gingivalis and protects gingival keratinocyte barrier function in an in vitro model

Background and objectives

Porphyromonas gingivalis, a late colonizer of the periodontal biofilm, has been strongly associated with the chronic form of periodontitis. The aim of this study was to investigate the effects of a Dual Zinc plus Arginine formulation (aqueous solution and dentifrice) on the pathogenic properties of P. gingivalis and the barrier function of an in vitro gingival epithelium model.

Results

The Dual Zinc plus Arginine aqueous solution and dentifrice inhibited the hemolytic and proteolytic activities of P. gingivalis. The Dual Zinc plus Arginine aqueous solution and dentifrice enhanced the barrier function of an in vitro gingival epithelium model as determined by a time-dependent increase in transepithelial electrical resistance and decrease in paracellular permeability. This was associated with an increased immunolabeling of two important tight junction proteins: zonula occludens-1 and occludin. The deleterious effects of P. gingivalis on keratinocyte barrier function as well as the ability of the bacterium to translocate through a gingival epithelium model were attenuated in the presence of either Dual Zinc plus Arginine aqueous solution or dentifrice.

Conclusions

The Dual Zinc plus Arginine formulation may offer benefits for patients affected by periodontal disease through its ability to attenuate the pathogenic properties of P. gingivalis and promote keratinocyte barrier function.

Clinical and Microbiological Effects of Weekly Supragingival Irrigation with Aerosolized 0.5% Hydrogen Peroxide and Formation of Cavitation Bubbles in Gingival Tissues after This Irrigation: A Six-Month Randomized Clinical Trial

Introduction

The study investigated the effect of weekly supragingival irrigation with aerosolized 0.5% hydrogen peroxide (H₂O₂) solution as a maintenance periodontal therapy on clinical and microbiological parameters in patients with chronic periodontitis. The other purpose was to investigate whether cavitation bubbles can penetrate not only into periodontitis-damaged tissues but also into ex vivo porcine healthy periodontal tissues.

Materials and Methods

The study included 35 systemically healthy patients with chronic periodontitis (CP). After nonsurgical periodontal debridement (NSPD), all patients were randomized into two groups: the Control group (NSDP alone, n = 18) and the Test group (NSDP plus supragingival irrigation, n = 17). Clinical (Approximal Plaque Index (API), Bleeding Index (BI), and Modified Gingival Index (MGI)) and microbiological (Polymerase Chain Reaction technology (using a micro-IDent® kit)) measurements were performed at the initial time point, 3 months, and 6 months after NSPD. The impact of supragingival irrigation on diseased gingival tissues of CP patients (n = 5) and on ex vivo porcine healthy gingival tissue samples (n = 3) was evaluated to estimate morphological changes in healthy and diseased gingival tissues.

Results

Morphological data revealed that supragingival irrigation caused the formation of cavitation bubbles in diseased gingival tissue of CP patients and in healthy porcine gingival tissues. The decrease in API, BI, and MGI scores after 6 months in the Test group significantly (p ≤ 0.01, p ≤ 0.05, and p ≤ 0.01, respectively) exceeded that in the Control group. Test group patients demonstrated a decrease in periodontal sites showing Pocket Probing Depth > 4 mm and, after 6 months, a statistically significant decrease in the proportion of periopathogenic bacteria.

Conclusion

The effectiveness of mechanical periodontal treatment combined with weekly supragingival irrigation with aerosolized 0.5% H₂O₂ solution on clinical and microbiological parameters of periodontal tissues of periodontitis patients is reliably higher than that of mechanical periodontal debridement alone. It has been found that cavitation bubbles as a result of irrigation with the aerosolized 0.5% hydrogen peroxide solution can form not only in periodontal tissues of periodontitis patients but also in ex vivo porcine healthy gingival tissues.

Sulfate-Reducing Bacteria of the Oral Cavity and Their Relation with Periodontitis-Recent Advances

The number of cases of oral cavity inflammation in the population has been recently increasing, with periodontitis being the most common disease. It is caused by a change in the microbial composition of the biofilm in the periodontal pockets. In this context, an increased incidence of sulfate-reducing bacteria (SRB) in the oral cavity has been found, which are a part of the common microbiome of the mouth. This work is devoted to the description of the diversity of SRB isolated from the oral cavity. It also deals with the general description of periodontitis in terms of manifestations and origin. It describes the ability of SRB to participate in its development, although their effect on periodontal inflammation is not fully understood. The production of hydrogen sulfide as a cytochrome oxidase inhibitor may play a role in the etiology. A meta-analysis was conducted based on studies of the occurrence of SRB in humans.

Further evidence on the relationship between abdominal aortic aneurysm and periodontitis: A cross-sectional study

BACKGROUND

Periodontitis is a chronic inflammatory disease characterized by Gram-negative bacteria responsible for the degradation of tissues surrounding tooth. Moreover, periopathogens can invade the bloodstream, disseminate and promote cardiovascular disease, such as the link between Porphyromonas gingivalis and atherosclerosis. The aim of this study was to explore the relationship between the severity of periodontitis and of abdominal aortic aneurysm (AAA).

METHODS

This cross-sectional study compared patients with stable AAA (n = 30) and patients with unstable AAA (n = 31) based on aortic diameter, growth rate, and eligibility for surgical intervention. Periodontal clinical parameters were recorded as well as the Periodontal Inflamed Surface Area and the Periodontal Index for Risk of Infectiousness (PIRI). Microbiological analyses were performed on saliva and supragingival and subgingival plaque. Quantification of Tannerella forsythia (Tf), Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans (Aa), Fusobacterium nucleatum (Fn), and Prevotella intermedia (Pi) was done by quantitative polymerase chain reaction.

RESULTS

The two AAA groups were homogeneous for age, sex, and most risk factors except hypertension and chronic obstructive pulmonary disease. Periodontal parameters were comparable but the proportion of patients with high PIRI scores was greater in those with unstable AAA (51.6% versus 23.3%). The probing depth (PD) and the proportion of PD >6 mm were positively correlated with AAA size and thrombus volume. Several associations were found between periopathogens such as Pg and AAA diameters and volumes, but no difference could be evidenced between stable and unstable AAA groups.

CONCLUSIONS

Periodontitis was highly prevalent in both stable and unstable AAA patients. Severe and progressive periodontitis (stage IV and grade C) tended to be more frequent in the group of patients with unstable AAA. Moreover, Pg was observed in all the samples (saliva, supragingival, and subgingival plaque) and was correlated with AAA diameters and volumes. The study evidenced potential relationships between periodontitis severity and size of AAA.

Periodontal conditions, retinopathy, and serum markers in individuals with type 1 diabetes

BACKGROUND

The prevalence of diabetes is high and increasing. Periodontitis has been identified as a risk factor in both type 1 and 2 diabetes. The study purpose was to assess periodontal conditions, retinopathy, and serum glutamic acid decarboxylase antibody (GADA) titers in relation to retinopathy in individuals with type 1 diabetes (T1D).

METHODS

The study is a case series. Adult individuals with a diagnosis of T1D (n = 85) monitored ≥5 years were recruited from an endocrinology clinic. Peripheral venous blood samples were analyzed including assessments of serum HbA1c levels and GADA titers. Medical and periodontal conditions were examined, and the data assessed. Independent t tests, binary and multivariate analyses, χ² and odds ratios were employed.

RESULTS

Gingivitis was found in 68.2%, periodontitis in 21.2%, and retinopathy in 64.7%, GADA (≥35 U/mL) in 54.1%, and serum HbA1c > 48 mmol/mol in 94.3% of the individuals. The unadjusted odds ratio for periodontitis to differentiate a diagnosis of retinopathy was 7.3 (95%CI 1.6, 4.4, P <0.01). Multivariate analyses identified the following dependent factors to differentiate retinopathy; age, T1D duration, gingivitis, periodontitis at P < 0.001, sex, and serum GADA at P < 0.01, and by the number of remaining teeth at P < 0.05.

CONCLUSION

Retinopathy as a complication to T1D is linked to the duration of diabetes, age of the individual and with increasing severity to periodontitis. Periodontal intervention studies are warranted.

New biodegradable nanoparticles-in-nanofibers based membranes for guided periodontal tissue and bone regeneration with enhanced antibacterial activity

Introduction

Guided tissue regeneration (GTR) and guided bone regeneration (GBR) are commonly used surgical procedures for the repair of damaged periodontal tissues. These procedures include the use of a membrane as barrier to prevent soft tissue ingrowth and to create space for slowly regenerating periodontium and bone. Recent approaches involve the use of membranes/scaffolds based on resorbable materials. These materials provide the advantage of dissolving by time without the need of surgical intervention to remove the scaffolds.

Objectives

This study aimed at preparing a new series of nanofibrous scaffolds for GTR/GBR applications with enhanced mechanical properties, cell adhesion, biocompatibility and antibacterial properties.

Methods

Electrospun nanofibrous scaffolds based on polylactic acid/cellulose acetate (PLA/CA) or poly(caprolactone) (PCL) polymers were prepared and characterized. Different concentrations of green-synthesized silver nanoparticles, AgNPs (1-2% w/v) and hydroxyapatite nanoparticles, HANPs (10-20% w/v) were incorporated into the scaffolds to enhance the antibacterial and bone regeneration activity.

Results

In-vitro studies showed that addition of HANPs improved the cell viability by around 50% for both types of nanofibrous scaffolds. The tensile properties were also improved through addition of 10% HANPs but deteriorated upon increasing the concentration to 20%. AgNPs significantly improved the antibacterial activity with 40 mm inhibition zone after 32 days. Additionally, the nanofibrous scaffolds showed a desirable degradation profile with losing around 40-70% of its mass in 8 weeks.

Conclusions

The obtained results show that the developed nanofibrous membranes are promising scaffolds for both GTR and GBR applications.

Comparison between Antimicrobial Photodynamic Therapy and Low-level laser therapy on non-surgical periodontal treatment: A Clinical Study

BACKGROUND

Alternative antibacterial therapeutic modalities, such as antimicrobial photodynamic therapy (aPDT) and low-level laser therapy (LLLT), have been proposed to improve the effectiveness of periodontal treatment. However, clinical studies evaluating the efficiency of these treatments have been inconclusive, partly due to contradictory results regarding their clinical and microbiological effects. The aim of this study was to evaluate the clinical effects of aPDT and LLLT after a one-stage full-mouth disinfection (OSFMD) protocol during periodontitis treatment.

METHODS

A split-mouth clinical trial was conducted in 20 patients presenting at least two contralateral teeth with a probing pocket depth (PD) ≥ 5 mm and bleeding on probing (BOP) on both sides of the mouth. All patients were submitted to an OSFMD protocol. The selected sites randomly received either (1) aPDT (methylene blue as a photosensitizer activated by red and infrared diode laser) or (2) LLLT (red and infrared diode laser). Clinical parameters were assessed at baseline and at 4 and 12 weeks post-treatment.

RESULTS

Both treatment protocols promoted significant reductions in PD, number of deep pockets and BOP and an increase in clinical attachment level (CAL) after 4 and 12 weeks, but there were no differences between the two groups. There was no change in the gingival level (GL) of either group for all periods of analysis. A decrease in the number of moderate pockets (4-5 mm) was found in the LLLT group (5.15 ± 4.20) when compared to the aPDT group (7.10 ± 5.24), but only after 4 weeks.

CONCLUSIONS

In conclusion, both the aPDT and LLLT therapies promoted improvements in periodontal clinical parameters after the OSFMD protocol; however, in general, there were no distinct differences between the two treatment modalities evaluated in this study.

Simultaneous photoablative and photodynamic 810-nm diode laser therapy as an adjunct to non-surgical periodontal treatment: an in-vitro study

BACKGROUND

The use of lasers at different wavelengths has been proposed in combination with conventional non-surgical periodontal treatment in order to improve the clinical outcome of periodontal disease. However, the clinical use of laser photonic energy is still the subject of research and debate because the antibacterial activity of the laser is dependent upon method, laser parameters, quantity of bacteria, species selected and photosensitizers used.

METHODS

We evaluated the in-vitro bactericidal activity of 810 nm diode-laser irradiation in simultaneous photoablative and photodynamic mode against the major pathogenic bacterial organisms associated with periodontal inflammation and disease. We used indocyanine green as photosensitizer and the high-energy density of 161.7 J/cm2 or 215.0 J/cm2 for the photoablative-photodynamic irradiation.

RESULTS

The bacteria were drastically affected by the 215.0 J/cm2 irradiation in the presence of indocyanine green. In fact, the number of Porphyromonas gingivalis and Prevotella intermedia was reduced by 99.9% (P<0.001), while the number of Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Actinomyces viscosus decremented by 83.3% (P<0.01), 86.8% (P<0.05), 75% (P<0.01) and 78.7% (P<0.001), respectively. P. gingivalis and P. intermedia were the only bacteria that were sensitive to the treatment with indocyanine green dye and 161.7 J/cm2 of laser irradiation (P<0.001).

CONCLUSIONS

Our preliminary in-vitro data suggest that simultaneous photoablative-photodynamic irradiation could be a promising therapy against a wide range of bacteria involved in periodontal disease. We believe that further additional in-vivo investigation is necessary, to enable a more complete picture of effectiveness within a clinical setting to be established. In addition, the use of a simultaneous photoablative-photodynamic therapy is suggested to reduce treatment time, without compromising the efficacy against the periodontal pathogens.

The association of clinically determined periodontal disease and edentulism with total cancer mortality: The National Health and Nutrition Examination Survey III

Increasing evidence supports a positive association between periodontal disease and total cancer risk. We evaluated the association of clinically assessed periodontal disease and a consequence, edentulism with total cancer mortality in participants without a prior cancer diagnosis in a U.S. nationally representative population. Included were 6,034 participants aged ≥40 years without a prior cancer diagnosis who participated in the National Health and Nutrition Examination Survey III. Periodontal health was measured by trained dentists. Cancer deaths (n = 702) were ascertained during a median of 21.3 years of follow-up. Cox proportional hazards regression was used to estimate the association of periodontal disease and edentulism with total cancer mortality using no periodontal disease/dentate as the reference and adjusting for potential demographic, lifestyle including smoking and social factor confounders. Fifteen percent had periodontitis and 17% were edentulous. Periodontitis was not statistically significantly associated with risk of total cancer death after multivariable adjustment. Edentulism was associated with an increased risk of cancer mortality (hazard ratio = 1.50, 95% confidence interval = 1.12-2.00) after multivariable adjustment, including in men and women and in each racial/ethnic group studied. The positive association was observed in overweight/obese participants but not participants with normal body mass index, more strongly in prediabetic/diabetic participants than in participants without diabetes and in ever cigarette smokers but not in never cigarette smokers. In this U.S. nationally representative population, those with edentulism, but not periodontal disease, had a higher risk of total cancer death, especially in those with shared risk factors for periodontal disease and cancer.

Herpesvirus-bacteria synergistic interaction in periodontitis

The etiopathogenesis of severe periodontitis includes herpesvirus-bacteria coinfection. This article evaluates the pathogenicity of herpesviruses (cytomegalovirus and Epstein-Barr virus) and periodontopathic bacteria (Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis) and coinfection of these infectious agents in the initiation and progression of periodontitis. Cytomegalovirus and A. actinomycetemcomitans/P. gingivalis exercise synergistic pathogenicity in the development of localized ("aggressive") juvenile periodontitis. Cytomegalovirus and Epstein-Barr virus are associated with P. gingivalis in adult types of periodontitis. Periodontal herpesviruses that enter the general circulation may also contribute to disease development in various organ systems. A 2-way interaction is likely to occur between periodontal herpesviruses and periodontopathic bacteria, with herpesviruses promoting bacterial upgrowth, and bacterial factors reactivating latent herpesviruses. Bacterial-induced gingivitis may facilitate herpesvirus colonization of the periodontium, and herpesvirus infections may impede the antibacterial host defense and alter periodontal cells to predispose for bacterial adherence and invasion. Herpesvirus-bacteria synergistic interactions, are likely to comprise an important pathogenic determinant of aggressive periodontitis. However, mechanistic investigations into the molecular and cellular interaction between periodontal herpesviruses and bacteria are still scarce. Herpesvirus-bacteria coinfection studies may yield significant new discoveries of pathogenic determinants, and drug and vaccine targets to minimize or prevent periodontitis and periodontitis-related systemic diseases.

Clinical and Radiographic Evaluation of Nanohydroxyapatite Powder in Combination with Polylactic Acid/Polyglycolic Acid Copolymer as Bone Replacement Graft in the Surgical Treatment of Intrabony Periodontal Defects: A Retrospective Case Series Study

The aim of this retrospective case series was to evaluate the clinical efficacy of nanohydroxyapatite powder (NHA) in combination with polylactic acid/polyglycolic acid copolymer (PLGA) as a bone replacement graft in the surgical treatment of intrabony periodontal defects. Medical charts were screened following inclusion and exclusion criteria. Periodontal parameters and periapical radiographs taken before surgery and at 12-month follow-up were collected. Intra-group comparisons were performed using a two-tailed Wilcoxon signed-rank test. Twenty-five patients (13 males, 12 females, mean age 55.1 ± 10.5 years) were included in the final analysis. Mean probing depth (PD) and clinical attachment level (CAL) at baseline were 8.32 ± 1.41 mm and 9.96 ± 1.69 mm, respectively. Twelve months after surgery, mean PD was 4.04 ± 0.84 mm and CAL was 6.24 ± 1.71 mm. Both PD and CAL variations gave statistically significant results (p < 0.00001). The mean radiographic defect depth was 5.54 ± 1.55 mm and 1.48 ± 1.38 mm at baseline and at 12-month follow-up, respectively (p < 0.0001). This case series, with the limitations inherent in the study design, showed that the combination of NHA and PLGA, used as bone replacement graft in intrabony periodontal defects, may give significant improvements of periodontal parameters at 12-month follow-up.

Study on oral hygiene by nanobubbles from high-density nozzle

An experiment was performed on oral bacteria removal using the design variables, which included the three-segment rotor speed of the testing device and three types of stainless steel meshes (with different layers). The overall hygienic results showed an effect of up to 95% bacteria removal, and some combinations had 100% hygienic effect. The study proposed that the use of nanobubble generated by a high-density stainless-steel mesh-manufactured nozzle removes dental bacteria. In addition, the device could also be used for auxiliary oral hygiene to decrease the frequency of future medical visits due to periodontal diseases or to enable the device to assist patients with severe periodontal disease more conveniently for oral hygiene.

Chronic periodontitis and community-acquired pneumonia: a population-based cohort study

BACKGROUND

This study aimed to determine the association between chronic periodontitis (CP) and community-acquired pneumonia (CAP) according to CP severity in the Korean population based on the National Health Insurance Service database.

METHODS

Data from the National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS), conducted from 2002 to 2013, were analyzed. A total of 363,541 participants were enrolled in this retrospective cohort study. Data on socio-demographic characteristics and CAP-related variables were collected. Participants were divided into 4 groups according to CP severity. Cox proportional hazards regression was performed after adjusting for sociodemographic and related covariates.

RESULTS

A total of 363,541 participants were included in the analysis. The number of CAP cases in the index period was 14,838 (4.1%). Among the 4 groups, the mean age was significantly higher in the severe CP group. The incidence rates of severe and non-severe CP were 5.68 and 4.99, respectively (per 103 person-years). The hazard ratio for CAP was not significant in any of the models regardless of the presence or absence of CP. On stratification analysis by sex, smoking and Charlson comorbidity index, there were no significant differences between CAP and CP in any of the models.

CONCLUSION

The results of this study show that CP may not be a potential risk factor for CAP.

Detection of periodontal microorganisms in coronary atheromatous plaque specimens of myocardial infarction patients: A systematic review and meta-analysis

BACKGROUND

Microbial translocation from inflamed periodontal pockets into coronary atheroma via systemic circulation is one of the proposed pathways that links periodontitis and myocardial infarction (MI). The purpose of this systematic review is to determine the reported prevalence of periodontal microorganisms in coronary atheroma and/or aspirated clot samples collected from MI patients with periodontal disease.

METHODOLOGY

The "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" (PRISMA) guidelines were followed. Six databases were systematically searched using Medical Subject Headings/Index and Entree terms. After a thorough screening, fourteen publications spanning over ten years (2007-2017) were eligible for this systematic review and meta-analysis.

RESULTS

Out of 14 included studies, 12 reported presence of periodontal bacterial DNA in coronary atherosclerotic plaque specimens. Overall, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans were the most frequently detected periodontal bacterial species. Meta-analysis revealed that the prevalence of P. gingivalis was significantly higher than A. actinomycetemcomitans in coronary atheromatous plaque samples. Apart from periodontal microbes, DNA from a variety of other microbes e.g. Pseudomonas fluorescens, Streptococcus species, Chlamydia pneumoniae were also recovered from the collected samples.

CONCLUSION

Consistent detection of periodontal bacterial DNA in coronary atheroma suggests their systemic dissemination from periodontal sites. It should further be investigated whether they are merely bystanders or induce any structural changes within coronary arterial walls.

Metabolomic Status of The Oral Cavity in Chronic Periodontitis

Chronic periodontitis is an inflammatory disease of tooth-supporting tissues associated with Porphyromonas gingivalis. Expansion and invasion of this bacterium into the periodontium is associated with changes in the metabolome of the oral cavity.

MATERIALS AND METHODS

Metabolomics analysis of mouth washout and tongue swab samples based on proton nuclear magnetic resonance (¹H-NMR) method was employed to determine metabolic status of the oral cavity in chronic periodontal disease.

RESULTS

Mouth washout extracts contained a total of 23 metabolites and tongue swab extracts contained 17. Identified metabolites partially overlap with the content of saliva and gingival crevicular fluid. The colonization of the oral cavity of patients with periodontitis by bacteria was manifested in the change in levels of eight metabolites.

CONCLUSION

NMR-based metabolomics analysis is a potentially useful methodological approach for monitoring the pathological processes observed in the oral cavity in the course of periodontitis.

Oral Microbiota Composition and Antimicrobial Antibody Response in Patients with Recurrent Aphthous Stomatitis

Recurrent aphthous stomatitis (RAS) is the most common disease of the oral mucosa, and it has been recently associated with bacterial and fungal dysbiosis. To study this link further, we investigated microbial shifts during RAS manifestation at an ulcer site, in its surroundings, and at an unaffected site, compared with healed mucosa in RAS patients and healthy controls. We sampled microbes from five distinct sites in the oral cavity. The one site with the most pronounced differences in microbial alpha and beta diversity between RAS patients and healthy controls was the lower labial mucosa. Detailed analysis of this particular oral site revealed strict association of the genus Selenomonas with healed mucosa of RAS patients, whereas the class Clostridia and genera Lachnoanaerobaculum, Cardiobacterium, Leptotrichia, and Fusobacterium were associated with the presence of an active ulcer. Furthermore, active ulcers were dominated by Malassezia, which were negatively correlated with Streptococcus and Haemophilus and positively correlated with Porphyromonas species. In addition, RAS patients showed increased serum levels of IgG against Mogibacterium timidum compared with healthy controls. Our study demonstrates that the composition of bacteria and fungi colonizing healthy oral mucosa is changed in active RAS ulcers, and that this alteration persists to some extent even after the ulcer is healed.

Effect of compliance during periodontal maintenance therapy on levels of bacteria associated with periodontitis: A 6-year prospective study

BACKGROUND

It is well established that regular compliance during periodontal maintenance therapy (PMT) maintains the stability of periodontal clinical parameters obtained after active periodontal therapy (APT). However, compliance during PMT has not yet been related to subgingival bacterial levels. Thus, this study followed individuals in PMT over 6 years and longitudinally evaluated the effects of compliance on periodontitis-associated bacterial levels and its relation to periodontal status.

METHODS

From a 6-year prospective cohort study with 212 individuals in PMT, 91 were determined to be eligible. From this total, 28 regular compliers (RC) were randomly selected and matched for age and sex with 28 irregular compliers (IC). Complete periodontal examination and microbiological samples were obtained 5 times: T1 (prior to APT), T2 (after APT), T3 (2 years), T4 (4 years), and T5 (6 years). Total bacteria counts and levels of Actinomyces naeslundii, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola were evaluated through quantitative polymerase chain reaction.

RESULTS

RC had less tooth loss and better clinical and microbiological conditions over time when compared with IC. IC had higher total bacterial counts and higher levels of T. denticola. Moreover, among IC, total bacterial counts were positively associated with plaque index and bleeding on probing, while levels of A. naeslundii, T. forsythia, and T. denticola were negatively associated with clinical attachment loss (4 to 5 mm) among RC.

CONCLUSIONS

Compliance positively influenced subgingival microbiota and contributed to stability of periodontal clinical status. Regular visits during PMT sustained microbiological benefits provided by APT over a 6-year period.

Prevalence of periodontitis and alveolar bone loss in a patient population at Harvard School of Dental Medicine

Background

Although several studies assessed the prevalence of alveolar bone loss, the association with several risk factors has not been fully investigated. The aim of this article is to measure the prevalence of periodontitis by calculating the mean alveolar bone loss/level of posterior teeth using bitewing radiographs among the patients enrolled in the clinics at Harvard School of Dental Medicine and address risk factors associated with the disease.

Methods

One thousand one hundred thirty-one patients were selected for radiographic analysis to calculate the mean alveolar bone loss/level by measuring the distance between the cementoenamel junction and the alveolar bone crest on the mesial and distal surfaces of posterior teeth. Linear regression with Multi-level mixed-effect model was used for statistical analysis adjusting for age, sex, race, median household income, and other variables.

Results

Mean alveolar bone level of the whole sample was 1.30 mm (±0.006). Overall periodontitis prevalence for the sample was 55.5% (±1.4%). Moderate periodontitis prevalence was 20.7% (±1.2%), while 2.8% (±0.5%) of the whole sample had severe periodontitis. Adjusted mean alveolar bone loss was higher in older age groups, males, Asian race group, ever smokers, and patients with low median household income.

Conclusion

The effect of high household income on the amount of bone loss can be powerful to the degree that high household income can influence outcomes even for individuals who had higher risks of developing the disease. Public health professionals and clinicians need to collaborate with policy makers to achieve and sustain high quality of healthcare for everyone.

Placental colonization with periodontal pathogens: the potential missing link

Observational studies demonstrate that women with severe periodontitis have a higher risk of adverse pregnancy outcomes like preterm birth and low birthweight. Standard treatment for periodontitis in the form of scaling and root planing during the second trimester failed to reduce the risk of preterm or low birthweight. It is premature to dismiss the association between periodontitis and adverse pregnancy outcomes because one explanation for the failure of scaling and root planing to reduce the risk of adverse pregnancy outcomes is that periodontal pathogens spread to the placental tissue prior to periodontal treatment. In the placenta, orally derived organisms could cause direct tissue damage or mediate a maternal immune response that impairs the growth of the developing fetus. Sequencing studies demonstrate the presence of organisms derived from the oral microbiome in the placenta, but DNA-based sequencing studies should not be the only technique to evaluate the placental microbiome because they may not detect important shifts in the metabolic capability of the microbiome. In humans, polymerase chain reaction and histology have detected periodontal pathogens in placental tissue in association with multiple adverse pregnancy outcomes. We conclude that both placental and oral microbiomes may play a role in periodontitis-associated adverse pregnancy outcomes. However, the measure to determine the association between periodontal pathogens in the placenta and adverse pregnancy outcomes should be the amount and prevalence, not the mere presence of such microorganisms. Placental colonization with periodontal pathogens thus potentially represents the missing link between periodontitis and adverse pregnancy outcomes.

Fabrication and in-vitro Investigation of Polycaprolactone - (Polyvinyl Alcohol/Collagen) Hybrid Nanofiber as Anti-Inflammatory Guided Tissue Regeneration Membrane

Background:

Periodontal disease is the most common oral condition that affects the tissue surrounding the teeth. The oral cavity is colonized by an impressive array of micro-organisms, many of which can colonize the implants such as Guided Tissue Regeneration (GTR) often utilized in recovering procedures that result in inflammation interfering with the bone regeneration.

Methods:

In the current study, a nano-hybrid GTR membrane is developed as a heliacal structure scaffold with localized drug delivery function (Ibuprofen) as an anti-inflammatory agent. Polycaprolactone (PCL) and a blend of Polyvinyl alcohol (PVA)/collagen (Col) (50/50) were electrospun by electrospinning. Ibuprofen (Ibu) was loaded once in the PCL context and once in the hydrophilic portion (PVA/Col).

Results:

The in vitro release behavior was investigated in each case. Chemical and physical properties were studied for each item. Morphology investigation indicated a heliacal structure with the total average diameter of 1266 nm consististing of porous pores with the average diameter of 256nm.

Conclusion:

The membranes indicated proper mechanical properties and appropriate biodegradation rate as a potential GTR membrane. The controlled and sustained release of Ibu was obtained from both PCL and PVA/COL loaded membranes. Kinetic model study indicated the following zero-order and Higuchi models for the optimum case of PCL loaded and PVA/Col Ibu loaded scaffolds respectively.

The association between clinically determined periodontal disease and prostate-specific antigen concentration in men without prostate cancer: the 2009-2010 National Health and Nutrition Examination Survey

PURPOSE

We evaluated the association between clinically assessed periodontal disease and serum prostate-specific antigen (PSA) concentration in men without a prostate cancer diagnosis in a US nationally representative sample of non-institutionalized men.

METHODS

Included were 1263 men aged ≥ 40 years who participated in the National Health and Nutrition Examination Survey in 2009-2010. Measurements of periodontal health and tooth count were used to define periodontal disease severity (no, mild, moderate, severe) and edentulism. Linear and logistic regressions were used to estimate the association of periodontal disease severity and edentulism with PSA concentration and elevated PSA, respectively.

RESULTS

Adjusting for age and other factors including race, body mass index, and education, the natural logarithm of PSA concentration did not change with increasing severity (mild - 0.20, 95% confidence interval [CI] - 0.34 to - 0.05; moderate - 0.12, 95% CI - 0.26 to 0.01; severe - 0.16, 95% CI - 0.43 to 0.12; edentulism - 0.16, 95% CI - 0.35 to 0.04; P-trend 0.13) compared with dentate men without periodontal disease. Although the multivariable-adjusted ORs of elevated PSA were not statistically significant, participants with more severe periodontal disease were less likely to have PSA > 2.0 and > 2.5 ng/mL, but more likely to have PSA > 4.0 ng/mL, compared to dentate men without periodontal disease. Similar non-significant associations with PSA were observed when comparing edentulous men to dentate men without periodontal disease.

CONCLUSIONS

In this US nationally representative sample, men with periodontal disease did not have higher serum PSA and were not more likely to have clinically elevated PSA after taking into account age and other factors, contrary to the hypothesis. This study suggests that periodontal disease does not notably affect the specificity of PSA for prostate cancer screening.

The Effect of Oral Health Knowledge, Attitude, and Practice on Periodontal Status among Dental Students

OBJECTIVES

 The primary aim of the current study is to relate oral health knowledge, attitude, and oral hygiene practice with the periodontal condition of both undergraduate and postgraduate dental students.

MATERIALS AND METHODS

 Data were collected through a combination of self-reported questionnaire and clinical examination. The estimated sample size was 246. Probing depths and clinical attachment loss were measured in interproximal sites, whereas the gingival index was calculated based on Ramfjord teeth. The Centers for Disease Control and the American Academy of Periodontology classification was used for periodontal diagnosis. The subjects were divided into three groups. Group 1 was composed of undergraduate, preclinical dental students, group 2 consisted of undergraduate clinical-year dental students, whereas group 3 included postgraduate residents.

RESULTS

 A total of 296 dental students participated in this study. Significant differences were found among the groups in their oral health knowledge, attitude, and practice scores. Gingival disease was detected among most of the participants (99.2-100%) with significant differences between different educational levels (group 1 = 1.13, group 2 = 1.16, group 3 = 0.96, p-value = 0.001). Sixty percent of dental students were diagnosed with periodontal disease regardless of its severity. A positive correlation was established between oral health knowledge and attitude and oral hygiene practice. In addition, gingival inflammation severity and the severity of periodontal disease showed a positive correlation.

CONCLUSIONS

 This study highlighted the need to improve the oral health knowledge, attitude, and practice of dental students. Gingival and periodontal inflammation was highly prevalent among participants.

Significance of oral health in adult patients with congenital heart disease

Due to improved diagnosis and treatment life expectancy of patients with congenital heart disease is steadily increasing resulting in a growing portion of adult patients. When entering, adulthood patients commonly show a shift in their specific needs for medical care. Since the treatment is mostly not curative many patients have life-long cardiovascular anomalies, among others, entailing high risk for the development of infective endocarditis. Several oral diseases, i.e., caries, apical periodontitis and periodontitis show a very high overall prevalence. These entities are primarily initiated by bacterial infections. Hence, they cause an inherent risk for bacteremia and subsequently for infective endocarditis in patients with congenital heart disease during professional dental care and various daily activities. Conversely congenital heart disease seems to be inevitably associated with considerable impairment of oral health resulting in a tight interrelation between both entities. Different preventive strategies are available to address the elevated risk for infective endocarditis due to oral diseases in patients with congenital heart disease during professional dental care and routine daily activities. This review delineates the current evidence regarding the issue of oral health in adult patients with congenital heart disease.

Mitigation of peri-implantitis by rational design of bifunctional peptides with antimicrobial properties

The integration of molecular and cell biology with materials science has led to strategies to improve the interface between dental implants with the surrounding soft and hard tissues in order to replace missing teeth and restore mastication. More than 3 million implants have been placed in the US alone and this number is rising by 500,000/year. Peri-implantitis, an inflammatory response to oral pathogens growing on the implant surface threatens to reduce service life leading to eventual implant failure, and such an outcome will have adverse impact on public health and create significant health care costs. Here we report a predictive approach to peptide design, which enabled us to engineer a bifunctional peptide to combat bacterial colonization and biofilm formation, reducing the adverse host inflammatory immune response that destroys the tissue surrounding implants and shortens their lifespans. This bifunctional peptide contains a titanium-binding domain that recognizes and binds with high affinity to titanium implant surfaces, fused through a rigid spacer domain with an antimicrobial domain. By varying the antimicrobial peptide domain, we were able to predict the properties of the resulting bifunctional peptides in their entirety by analyzing the sequence-structure-function relationship. These bifunctional peptides achieve: 1) nearly 100% surface coverage within minutes, a timeframe suitable for their clinical application to existing implants; 2) nearly 100% binding to a titanium surface even in the presence of contaminating serum protein; 3) durability to brushing with a commercially available electric toothbrush; and 4) retention of antimicrobial activity on the implant surface following bacterial challenge. A bifunctional peptide film can be applied to both new implants and/or repeatedly applied to previously placed implants to control bacterial colonization mitigating peri-implant disease that threatens dental implant longevity.

Association between regular walking and periodontitis according to socioeconomic status: a cross-sectional study

Physical activity reduces the risk and mortality risk of inflammatory diseases. This study aimed to examine the relationship between regular walking and periodontitis in a Korean representative sample of adults according to socioeconomic status. Data acquired by the Sixth Korea National Health and Nutrition Examination Survey in 2014 and 2015 were used. The survey was completed by 11,921 (5,175 males; 6,746 females) participants (≥19 years). Individuals without values on periodontitis were excluded, and 9,728 participants remained. Multivariable logistic regression analysis was done using socio-demographic characteristics (age, gender, income, education), oral health-related variables (flossing, interdental brushing, community periodontal index), oral and general health status and behaviour (smoking, diabetes mellitus), and regular walking. In all models, subjects who walked regularly had significantly lower risks of periodontitis. After adjusting for age, gender, income, education, smoking, diabetes mellitus, flossing, and interdental brushing, the odds ratio for periodontitis in subjects who walked regularly was 0.793 (95% Confidence interval: 0.700-0.898). Non-regular walking groups showed similar social gradients. Risk of low socioeconomic status was not significant in the regular walking group after adjusting for age, gender, income, and education. This study found that regular walking is associated to lower prevalence of periodontitis and can attenuate the relationship between periodontitis and low socioeconomic status.

Is selective protein adsorption on biomaterials a viable option to promote periodontal regeneration?

Periodontitis is an inflammatory condition that can induce significant destruction of the periodontium, the set of specialized tissues that provide nourishment and support to the teeth. According to the guided tissue regeneration principles, the periodontium can be regenerated if the spatiotemporal control of wound healing is obtained, namely the tune control of cell response. After material implantation, protein adsorption at the interface is the first occurring biological event, which influences subsequent cell response. With the regard of this, we hypothesize that the control of selective adsorption of biological cues from the surrounding milieu may be a key-point to control selective cell colonization of scaffolds for periodontal tissue regeneration.

Association between interleukin-10 gene polymorphisms and severe chronic periodontitis

OBJECTIVE

Periodontitis is an inflammatory disease that is a result of the interaction between pathogenic bacteria and host immune response. Genetic alterations in interleukin-10 (IL-10) gene may be associated with the increased risk of periodontitis. We investigated the association between genotype and haplotype frequencies of IL-10 gene polymorphisms and susceptibility to periodontitis in an Iranian population.

METHODS

In this case-control study, a total of 64 patients with periodontitis and 128 healthy subjects were recruited. The PCR-RFLP technique was used to detect IL-10 promoter genotypes at the positions of -1082 (G/A), -819 (C/T), and -592 (C/A) in association with the susceptibility to severe chronic periodontitis.

RESULTS

Regarding IL-10 -592 (C/A) and IL-10 -819 (C/T) alleles and genotypes, no significant association was observed between the risk of periodontitis and genotype frequencies. However, the frequency of GG genotype in IL-10 -1082 (G/A) polymorphic region was higher in normal subjects and was associated with the decreased risk of periodontitis under recessive model [OR = 2.89, 95% CI (0.99-8.43), p = 0.039]. Haplotype analysis revealed a significantly higher presence of H7 (AGC; -592/-1082/-819) [OR = 97.74, 95% CI (95.52-99.96), p < 0.0001].

CONCLUSION

IL-10 -1082(G/A) polymorphism and AGC (-592/-1082/-819) haplotype could be associated with the susceptibility to chronic periodontitis.

The ATC/TTC haplotype in the Interleukin 8 gene in response to Gram-negative bacteria: A pilot study

OBJECTIVE

The aim of this study was to investigate the functionality of ATC/TTC (Hap-1) and ATT/TTC (Hap-2) Interleukin (IL) 8 gene haplotypes in the response of neutrophils to Gram-negative bacteria associated with periodontitis.

DESIGN

Neutrophils were isolated by gradient centrifugation from whole peripheral blood of systemically healthy individuals presenting the two IL8 gene haplotypes. Neutrophils were stimulated with P. gingivalis, A. actinomycetemcomitans and PMA/ionomycin. Cytokine gene expression (RT-qPCR) and migration/chemotaxis (boyden chamber assay) were compared according to the presence of Hap-1 or Hap-2 haplotypes. Protein production was also evaluted in the multiplex assay using the mixed population of leukocytes present in the whole blood from the same individuals. The influence of these two haplotypes on the IL8 promoter activity was assessed in gene-reporter experiments.

RESULTS

Hap-1 haplotype in neutrophils and leukocytes exacerbated the response to stimulation with Gram-negative bacteria, with higher levels of TNF-α (mRNA and protein), IL-1β, IL-2R and IFN-γ (protein) and with increased chemotaxis. Presence of the T allele at the rs4071 polymorphism (alias -251) was associated with increased activity of IL8 proximal promoter.

CONCLUSIONS

Neutrophils and leukocytes carrying the Hap-1 haplotype (ATC/TTC) in the IL8 gene present an enhanced response to stimulation with Gram-negative bacteria associated with periodontitis. Presence of the T allele (rs4073) in the IL8 proximal promoter increases transcription activity.

Dental hypofunction alters subgingival microorganisms: a pilot study

BACKGROUND

The aim of this study was to evaluate dental plaque compositions, vascular endothelial growth factor (VEGF) and hypoxia-inducible factor (HIF) 1-alpha levels in gingival crevicular fluid (GCF) at hypofunctional and normofunctional teeth in healthy individuals and chronic periodontitis patients.

METHODS

Sixty systemically healthy individuals were enrolled. Study groups were: group 1 hypofunctional healthy group (group 1, N.=15); group 2 hypofunctional periodontitis group (group 2, N.=15); group 3 normofunctional healthy group (group 3, N.=15); and group 4 normofunctional periodontitis group (group 4, N.=15). Clinical periodontal measurements (plaque index, gingival index and clinical attachment level) were recorded. Dental plaque and GCF samples were taken. VEGF and HIF 1-alpha levels in GCF were determined. Subgingival plaque samples were evaluated for 11 different bacterial species as, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, Peptostreptococcus micros, Fusobacterium nucleatum, Campylobacter rectus, Eubacterium nodatum, Eikenella corrodens and Capnocytophaga species.

RESULTS

Tannerella forsythia, Peptostreptococcus micros, Eubacterium nodatum levels decreased in hypofunctional healthy and periodontitis groups (P<0.05). Porphyromonas gingivalis levels increased in hypofunctional healthy group and decreased in hypofunctional periodontitis group (P<0.05). There was also a decrease in Eikenella corrodens levels in hypofunctional periodontitis group (P<0.05). There were no difference regarding the Aggregatibacter actinomycetemcomitans, Capnocytophaga spp., Prevotella intermedia and Fusobacterium nucleatum levels among the groups (P>0.05). VEGF and HIF-1α levels in both GCF and serum samples were also similar (P>0.05).

CONCLUSIONS

Within the limits of this study, the authors found that the levels of four significant bacterial strains were decreased in both hypofunctional healthy and hypofunctional periodontitis groups compared to normofunctional equivalents. Though not evaluated in this study, this situation could be due to periodontal ligament atrophy and related physiological alterations.

Quaternized Zn(II) phthalocyanines for photodynamic strategy against resistant periodontal bacteria

Photodynamic inactivation (PDI) has been featured as an effective strategy in the treatment of acute drug-resistant infections. The efficiency of PDI was evaluated against three periodontal pathogenic bacteria that were tested as drug-resistant strains. In vitro studies were performed with four water-soluble cationic Zn(II) phthalocyanines (ZnPc1-4) and irradiation of a specific light source (light-emitting diode, 665 nm) with three doses (15, 36 and 60 J/cm2). The well detectable fluorescence of ZnPcs allowed the cellular imaging, which suggested relatively high uptakes of ZnPcs into bacterial species. Complete photoinactivation was achieved with all studied ZnPc1-4 for Enterococcus faecalis (E. faecalis) at a light dose of 15 J/cm2. The photodynamic response was high for Prevotella intermedia (P. intermedia) after the application of 6 μM of ZnPc1 and a light dose of 36 J/cm2 and for 6 μM of ZnPc2 at 60 J/cm2. P. intermedia was inactivated with ZnPc3 (4 log) and ZnPc4 (2 log) with irradiation at an optimal dose of 60 J/cm2. Similar photoinactivation results (2 log) were achieved for Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) treated with 6 μM ZnPc1 and ZnPc2 at a light dose of 60 J/cm2. The study suggested that PDI with quaternized Zn(II) phthalocyanines and specific light irradiation appears to be a very useful antimicrobial strategy for effective inactivation of drug-resistant periodontal pathogens.

The effect of triamcinolone in liposomes on oral wound healing in rats

The purpose of this study was to determine whether oral mucosa wounds in rats can be successfully treated with triamcinolone acetonide (TA), incorporated into liposomes. A round wound was inflicted on the oral mucosa of female Wistar rats divided into four groups of 12 animals. This wound was treated topically from day 1 with liposomes without the inclusion of TA and liposomes containing 0.01% or 0.05% TA. The wounds of the animals in the control group were not treated. Polymethyl metacrylate was used as an ointment for mixing in liposomes. The size of the wound was measured until day 6. The area of inflammatory infiltrate under the wound was evaluated by histopathology, the expression of iNOS (inducible nitric oxide synthase) enzyme under the wound was evaluated by immunohistochemistry until day 6. On the sixth day of experiment, the size of the wound and the area of the inflammatory infiltrate was the smallest in the group receiving empty liposomes (EL). Expression of iNOS was the most reduced in the group receiving EL. We conclude that oral mucosa wounds can be successfully treated with liposomes, although the incorporated drug triamcinolone would not be the appropriate drug for treating wounds of traumatic origin.

Quantification of TNF-α in Patients with Periodontitis and Type 2 Diabetes

OBJECTIVE

The present study aimed to compare variations in quantified tumor necrosis factor-alpha (TNF-α) levels in patients with periodontitis stage 2 grade B (POD2B) and/or type 2 diabetes (T2D) and to identify any relationships between this cytokine and these diseases.

METHODS

Levels of the cytokine TNF-α in gingival crevicular fluid in patients with POD2B and/or T2D were evaluated. A total of 160 subjects were distributed into four groups: those with POD2B (n=44); those with T2D (n=37); those with POD2B/T2D (n=40); and healthy subjects (n=39). Glycosylated hemoglobin (HbA1c) and blood glucose (BG) levels were quantified in each subject. Data were collected on body mass index (BMI), loss of insertion (LI), and probe depth (PD). Gingival crevicular fluid samples were collected from the most acutely affected periodontal pocket and gingival sulcus in each subject, and TNF-α was quantified by multiplex analysis.

RESULTS

Kruskal Wallis tests was used to identify differences in TNF-α levels, LI, PD, BMI, BG, and HbA1c by group. Differences (p<0.001) were found for LI, PD, BG, and HbA1c. A Spearman test was used to calculate possible correlations between TNF-α levels and LI or PD identified a weak but significant negative correlation of TNF-α with LI (Rho=-0199; p=0.012), and a moderately positive correlation of LI with PD (Rho=0.509; p < 0.001).

CONCLUSIONS

No variation was found between TNF-α levels and the presence of POD2B, POD2B/T2D, or T2D, suggesting the absence of any direct relationship between progression of these diseases and TNF-α levels. However, a correlation was present between low TNF-α concentrations and greater LI.

Bee venom attenuates Porphyromonas gingivalis and RANKL-induced bone resorption with osteoclastogenic differentiation

Porphyromonas gingivalis (P. gingivalis) is one of the major periodontal pathogens leading to inflammation and alveolar bone resorption. Bone resorption is induced by osteoclasts, which are multinucleated giant cells. Osteoclastic bone resorption is mediated by enhanced receptor activator of nuclear factor-kappa B ligand (RANKL) signaling. Therefore, the down-regulation of RANKL downstream signals is regarded as an effective therapeutic target in the treatment of bone loss-associated disorders. The aim of this study was to evaluate whether purified bee venom (BV) could attenuate P. gingivalis-induced inflammatory periodontitis and RANKL-induced osteoclast differentiation. Inflammatory periodontitis induced by P. gingivalis increased alveolar bone resorption and increased expression of TNF-α and IL-1β, while BV treatment resulted in decreased bone loss and pro-inflammatory cytokines. Similarly, RANKL-induced multinucleated osteoclast differentiation and osteoclast-specific gene expression, such as nuclear factor of activated T cells 1 (NFATc1), cathepsin K, tartrate-resistant acid phosphatase (TRAP), and integrin αvβ3 were significantly suppressed by treatment with BV. We show that BV reduces P. gingivalis-induced inflammatory bone loss-related periodontitis in vivo and RANKL-induced osteoclast differentiation, activation, and function in vitro. These results suggest that BV exerts positive effects on inflammatory periodontitis associated osteoclastogenesis.

Periodontal pathogenic bacteria among high school children in Saudi Arabia

BACKGROUND

The periodontal tissues are continuously exposed to specific bacterial components that have the ability to alter many local functions. Normal endogenous infections in healthy mouths cause disease when their numbers increase significantly.

OBJECTIVE

Determine the percentage of different periodontal pathogenic bacteria and their association with periodontal status.

DESIGN

Cross-sectional, analytical.

SETTINGS

School children of both genders in Saudi Arabia.

PATIENTS AND METHODS

Clinical examination consisted of measurement of the gingival and periodontal supporting tissue including attachment loss, probing pocket depth and furcation involvement following the National Health and Nutrition Examination Survey (NHANES) and taking samples of the subgingival bacterial flora.

MAIN OUTCOME MEASURES

The percentage of periodontal pathogenic bacteria and its association with periodontal status in Saudi Arabia.

SAMPLE SIZE

Bacterial samples were collected from 277 subjects.

RESULTS

Aggregatibacter actinomycetemcomitans was present in 21.7% of the subjects, Porphyromonas gingivalis in 21.3%; Tannerella forsythia in 10.1%; Treponema denticola in 34.7% and Prevotella inter-media in 12.3%. The red complex bacteria were found in 2.9% of the subjects.

CONCLUSIONS

The percentages of bacteria varied but only T denticola was significantly associated with periodontal breakdown. In addition, the presence of more than 2 of the 5 species tested were significantly associated with tissue damage.

LIMITATIONS

Cannot be generalized to all of Saudi Arabia. Larger controlled studies are needed.

CONFLICT OF INTEREST

None.

Efficacy of Locally Administered 1.2% Rosuvastatin Gel in Patients with Periodontitis: A Randomized Placebo Controlled Clinical Trial

Objective Periodontitis initiation and progression are a result of host immune inflammatory response to oral pathogens. Several pharmacological agents are being delivered locally, to improve periodontal health. Hence, the present randomized placebo controlled clinical trial is designed to check the clinical and antimicrobial efficacy of locally delivered 1.2% rosuvastatin (RSV) in intrabony defects (IBD) in periodontitis patients.

Materials and Methods One-hundred patients were randomly allotted into two treatment groups: group A received 1. 2% RSV gel, scaling and root debridement and group B received placebo gel, scaling and root debridement. Clinical parameters, including modified sulcus bleeding index (mSBI), probing depth (PD), clinical attachment level (CAL), and plaque index (PI), were recorded at baseline before phase 1 and after 6 months. Radiographic assessment of IBD was done by cone beam computed tomography at baseline and after 6 months. Anaerobic colony count was done at baseline and after 180 days.

Results On intragroup comparison, there is a significant improvement in periodontal parameters in both the groups. On intergroup comparison, there is significant gain in CAL in group A than group B ( p = 0.04). There is significant decrease in PD in group A, compared to group B. There is significant bone fill in group A ( p = 0.034), compared to group B. With respect to mSBI, PI, and anaerobic colony count, there is no significant difference between the two groups after 6 months. No adverse effect was noticed in any subjects.

Conclusion The author concludes that 1.2% RSV gel when delivered locally into IBD improved periodontal clinical parameters such as PD and CAL and showed significant bone fill.

Antimicrobial capacity of Leucocyte-and Platelet Rich Fibrin against periodontal pathogens

Various studies have described the biological properties of the Leucocyte- and Platelet Rich Fibrin (L-PRF) such as the antimicrobial effect against wound bacteria, but less is known about the effect against periodontal pathogens. The aim of this study was to evaluate the antibacterial properties of the L-PRF membrane and L-PRF exudate against the main periopathogens cultured on agar plates and in planktonic solution. This study demonstrated the antibacterial effect of the L-PRF membrane against P. intermedia, F. nucleatum, and A. actinomycetemcomitans, but especially against P. gingivalis. The L-PRF exudate also showed a strong inhibition against P. gingivalis on agar plates. No inhibition could be observed for the other bacterial strains. Moreover, L-PRF exudate decreased the number of viable P.gingivalis in a planktonic solution in a dose-dependent way. However, A. actinomycetemcomitans showed an increased growth in planktonic solution when in contact with the L-PRF exudate.

Evaluation of the effect of oleuropein on alveolar bone loss, inflammation, and apoptosis in experimental periodontitis

THE OBJECTIVE

The present study aimed to evaluate the effects of oleuropein on ligature-induced alveolar bone loss. In this respect, osteoblastic activity, osteoclastic activity, inflammatory markers, and apoptosis were evaluated.

BACKGROUND

Oleuropein is a flavonoid, which has potent anti-inflammatory and bone-protective effects.

METHODS

Thirty-two Wistar rats were divided into four experimental groups as following: control (C, n = 8) group; periodontitis (P, n = 8) group; periodontitis and low-dose oleuropein group (12 mg/kg/day oleuropein, LDO group, n = 8); and periodontitis and high-dose oleuropein group (24 mg/kg/day oleuropein, HDO group, n = 8). Periodontitis was induced via ligatures. Study period was 14 days, and animals were sacrificed at end of this period. Mandibles were examined via a stereomicroscope and underwent histological procedures. Osteoblast, tartrate-resistant acid phosphatase (TRAP)-positive osteoclast, and inflammatory cell counts were determined in hematoxylin-eosin stained sections. Inducible nitric oxide synthase (iNOS), bone morphogenetic protein-4, the cluster of differentiation (CD)-68, cysteine-aspartic proteases-3 (Caspase 3), and B-cell lymphoma-2 (Bcl-2) expressions were evaluated via immunohistochemistry.

RESULTS

Periodontitis group had highest alveolar bone loss, and these levels significantly decreased in LDO and HDO groups. Both 12 and 24 mg/kg oleuropein groups significantly increased osteoblast cell counts and decreased TRAP-positive osteoclast and inflammatory cell counts. BMP-4 and bcl-2 expressions were elevated in oleuropein groups while caspase-3 expressions decreased. iNOS and CD68 were higher in periodontitis group compared to control group, but there was no significant difference between other groups.

CONCLUSION

Oleuropein successfully decreased alveolar bone loss as a result of decreased osteoclastic activity, inflammation, and apoptosis and increased osteoblastic activity.

In Vitro and In Vivo Studies of Hydrophilic Electrospun PLA95/β-TCP Membranes for Guided Tissue Regeneration (GTR) Applications

The guided tissue regeneration (GTR) membrane is a barrier intended to maintain a space for alveolar bone and periodontal ligament tissue regeneration but prevent the migration of fast-growing soft tissue into the defect sites. This study evaluated the physical properties, in vivo animal study, and clinical efficacy of hydrophilic PLA95/β-TCP GTR membranes prepared by electrospinning (ES). The morphology and cytotoxicity of ES PLA95/β-TCP membranes were evaluated by SEM and 3-(4,5-cimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) respectively. The cementum and bone height were measured by an animal study at 8 and 16 weeks after surgery. Fifteen periodontal patients were selected for the clinical trial by using a commercial product and the ES PLA95/β-TCP membrane. Radiographs and various indexes were measured six months before and after surgery. The average fiber diameter for this ES PLA95/β-TCP membrane was 2.37 ± 0.86 µm. The MTT result for the ES PLA95/β-TCP membrane showed negative for cytotoxicity. The significant differences in the cementum and bone height were observed between empty control and the ES PLA95/β-TCP membrane in the animal model (p < 0.05). Clinical trial results showed clinical attachment level (CAL) of both control and ES PLA95/β-TCP groups, with a significant difference from the pre-surgery results after six months. This study demonstrated that the ES PLA95/β-TCP membrane can be used as an alternative GTR membrane for clinical applications.

Porphyromonas gingivalis and digestive system cancers

Porphyromonas gingivalis (P. gingivalis) is an anaerobic gram-negative bacterium that colonizes in the epithelium and has been strongly associated with periodontal disease. Recently, various degrees of associations between P. gingivalis and digestive system cancers, including oral squamous cell carcinoma in the oral cavity, oesophageal squamous carcinoma in the digestive tract, and pancreatic cancer in pancreatic tissues, have been displayed in multiple clinical and experimental studies. Since P. gingivalis has a strong association with periodontal diseases, not only the relationships between P. gingivalis and digestive system tumours but also the effects induced by periodontal diseases on cancers are well-illustrated in this review. In addition, the prevention and possible treatments for these digestive system tumours induced by P. gingivalis infection are also included in this review. At the end, we also highlighted the possible mechanisms of cancers caused by P. gingivalis. One important carcinogenic effect of P. gingivalis is inhibiting the apoptosis of epithelial cells, which also plays an intrinsic role in protecting cancerous cells. Some signalling pathways activated by P. gingivalis are involved in cell apoptosis, tumourigenesis, immune evasion and cell invasion of tumour cells. In addition, metabolism of potentially carcinogenic substances caused by P. gingivalis is also one of the connections between this bacterium and cancers.