Advances in the pathogenesis of periodontitis: summary of developments, clinical implications and future directions

Differences in the oral and intestinal microbiotas in pregnant women varying in periodontitis and gestational diabetes mellitus conditions

Background: The present study aimed to investigate the potential association between oral and intestinal microbiotas of pregnant women with periodontitis and/or gestational diabetes mellitus (GDM) in the second trimester.Methods: Four groups were defined: periodontitis (n = 28), GDM (n = 7), periodontitis + GDM (n = 7), and periodontitis- and GDM-free controls (n = 27). The oral and intestinal microbiomes were analyzed using the 16S rRNA sequencing technique.Results: Periodontitis alone significantly decreased the oral microbial diversity (by Shannon index, p = 0.003) and changed the structure of the oral microbial community (by AMOVA, p 0.001). GDM alone significantly increased the oral microbial diversity (by Shannon index, p = 0.049), and when combined with periodontitis, GDM significantly decreased the intestinal microbial richness (by observed species, p = 0.018) and influenced the structure of intestinal microbial community (by AMOVA, p = 0.043). The differentially abundant microbial taxa among different groups in both oral and intestinal samples were identified by LEfSe analysis, and limited taxa showed consistent trends. The numbers and ratios of oral-intestinal shared operational taxonomical units were the least in the periodontitis + GDM group.Conclusions: A close relationship between the oral microbiota and pregnant periodontitis was shown. Significant changes occur in both the oral and intestinal microbiomes when periodontitis was coupled with GDM. A separate influence of periodontitis and GDM on the oral and intestinal microbiotas may be indicated.

Current Concepts in the Management of Periodontitis

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

Effect of non-surgical periodontal therapy on serum ferritin levels in postmenopausal women with chronic periodontitis

Background. Ferritin is a positive acute phase protein (APP) in inflammation and chronic infections, including chronic periodontitis. Two key factors that can regulate ferritin expression are iron and pro-inflammatory cytokines. Serum ferritin levels increase after menopause, affecting women’s health. This study aimed to evaluate serum ferritin levels in postmenopausal women upon undertaking non-surgical periodontal treatment.

Methods. In this cross-sectional study, blood samples of 38 postmenopausal women with chronic periodontitis were collected before any treatment. The serum ferritin levels and periodontal parameters, probing depth (PD), clinical attachment level (CAL), and gingival index (GI) were recorded at baseline and three months after non-surgical periodontal therapy. Wilcoxon test was used to compare serum ferritin levels before and after treatment. T-test was used for comparison of periodontal parameters, with a P value of ≤0.05 considered significant.

Results. A decrease was observed in the serum ferritin level (from 108.55 mcg/L to 98.28 mcg/L) after treatment compared to baseline (P < 0.001). Also, significant improvements in periodontal parameters were observed compared to the baseline (P < 0.001).

Conclusion. Based on the results, it can be concluded that non-surgical periodontal treatment significantly reduces serum ferritin levels in postmenopausal women with chronic periodontitis.

Comparative evaluation of serum cotinine levels in chronic periodontitis and chronic obstructive pulmonary disease

Context:

Periodontitis and chronic obstructive pulmonary disease (COPD) are chronic progressive inflammatory conditions. Smoking has been associated with both chronic periodontitis and COPD. Hence, the present study was designed to correlate serum levels of cotinine with the severity of periodontal disease with or without COPD.

Settings and Design:

A total of eighty patients, twenty healthy individuals, twenty patients with chronic generalized periodontitis without smoking and without COPD, twenty patients who are smokers with chronic periodontitis without COPD and twenty patients who are smokers with chronic periodontitis and COPD in the age range of 43–65 years were selected for the study.

Subjects and Methods:

Serum cotinine level assessment, smoking history, and periodontal examination were done in all the patients and the data obtained were statistically analyzed.

Results:

The mean serum cotinine level was highest in smokers with chronic periodontitis and COPD (93.642 ± 14.727) and it differed significantly between the four groups (P < 0.001). There is a significant positive correlation between the number of cigarettes and serum cotinine levels in both groups involving smoking. There was no significant correlation between serum cotinine level and clinical attachment loss in chronic periodontitis smokers with or without COPD.

Conclusions:

The result of this study indicates that increased smoking with COPD causes a higher chance of progression of periodontal destruction but it is not statistically significant. Furthermore, this study indicates that the assessment of serum cotinine levels is a reliable method to evaluate smoking exposure.

The expression levels of MicroRNA-146a, RANKL and OPG after non-surgical periodontal treatment

OBJECTIVE

MicroRNA-146a (miR-146a) is a regulator of inflammatory response. Periodontitis is a disease with immune pathophysiology of the periodontium in which the inflammation results in the destruction of the soft tissues and alveolar bone. Therefore, the aim of this study was to investigate the expressions of miR-146a, OPG, and RANKL in diseased and healthy periodontal tissues to understand whether miR-146a expression level may associate with OPG and RANKL mRNA levels and OPG/RANKL ratio after non-surgical periodontal treatment.

METHODS

The levels of miR-146a, RANKL, and OPG in gingival tissues from patients with generalized periodontitis stages II and III and grades A and B (n = 15, group A), patients with generalized periodontitis stages III and IV and grade C (n = 15, group B), and healthy individuals (n = 10) were determined by real-time PCR. The associations of miR-146a expression with OPG and RANKL levels were evaluated.

RESULTS

The levels of miR-146a in two subgroups within periodontitis patients were significantly higher than healthy subjects (P < 0.0001). MiR-146a showed the increased level in group A of patients compared with group B (P < 0.05). Clinical parameters such as probing depth (PD) and clinical attachment loss (CAL) were significantly higher in patients than control group (P < 0.05). The levels of OPG and RANKL were increased in patients compared with healthy subjects, although the elevated levels were not statistically significant. MiR-146a was not associated with OPG and RANKL levels and OPG/RANKL ratio.

CONCLUSIONS

The results of this study failed to show the associations of miR-146a level with OPG and RANKL levels and OPG/RANKL ratio in periodontitis after non-surgical periodontal treatment.

Association Between the Extent of Periodontal Inflammation and the Severity of Rheumatoid Arthritis in Japanese Patients With Rheumatoid Arthritis

OBJECTIVE

Periodontal inflammation can affect the progression of rheumatoid arthritis (RA), and RA drugs may influence the periodontal condition of patients with RA. We examined whether the association between periodontal inflammation and the severity of RA is influenced by RA medication.

METHODS

This cross-sectional study recruited 98 Japanese patients with RA from an orthopaedic clinic. We assessed the severity of RA using the Steinbrocker class and stage. The periodontal inflamed surface area (PISA) was used as an indicator of periodontal status. We obtained data on RA medications from medical records. We examined the associations among periodontal tissue inflammation, RA medications, and RA severity using multinomial logistic regression analyses.

RESULTS

In univariate multinomial logistic regression analyses, no significant association between PISA score and RA severity was observed. There was no significant association between PISA score and RA severity in multivariate analyses not including variables about RA drugs as independent variables. However, in multivariate analyses adjusted for RA drugs and other confounding variables, patients with a PISA >550 mm2 had significantly higher odds ratios (ORs) for Steinbrocker class III-IV and stage III-IV (OR, 20.24; 95% confidence interval [CI], 1.78-229.85 and OR, 12.42; 95% CI, 1.79-86.49, respectively) compared to patients with PISA score ≤550 mm2.

CONCLUSION

The extent of periodontal inflammation is associated with the severity of RA independent of RA medications.

Prevalence of Dental Caries and Periodontal Disease of High School Students Aged 15 to 18 Years in Taiwan

The purpose of this study was to assess the prevalence and distribution of dental caries and periodontal disease in Taiwanese high school students aged 15–18. A total of 1069 Taiwanese students participated in a cross-sectional nationwide dental survey. By using a stratified method based on the National Health Insurance administration regions, 24 high schools were randomly sampled in different areas of Taiwan. The participants were examined with dental mirrors and community periodontal index (CPI) probes without using radiographs, to measure dental caries and periodontal status. Demographic information and other relevant risk indicators for the two diseases were gathered via a self-report questionnaire. In this study population, the weighted mean decayed, missing and filled teeth (DMFT) scores for ages 15 to 18 were 5.2, 6.1, 6.1, and 5.7. The weighted mean decayed, missing and filled surfaces (DMFS) scores were 9.0, 12.0, 13.1, and 11.2 at ages 15, 16, 17, and 18, respectively. Additionally, 88.2% of the subjects had periodontal disease, with calculus as the most prevalent type. Moreover, 5.2% of these students showed loss of attachment. There was no significant association between dental caries and periodontal disease. Dental caries and periodontal disease were prevalent among Taiwanese high school students in this national dental survey.

Impact of Smoking on Neutrophil Enzyme Levels in Gingivitis: A Case-Control Study

Background: The determination of the impact of risk factors such as smoking in periodontal disease development is of importance to better characterize the disease. However, its impact on host response remains unclear. This study aimed to evaluate the effects of tobacco smoking on GCF levels of neutrophil enzymes (myeloperoxidase (MPO), beta-glucuronidase (BGD), neutrophil elastase (NE) and periodontal parameters in healthy young adults with dental plaque biofilm-induced gingivitis. Methods: The study population consisted of 60 systemically healthy young adults (39 smokers (Sm) and 21 non-smokers (n-Sm)) diagnosed with plaque-induced gingivitis. The periodontal examination consisted of a plaque index (PI); gingival index (GI); probing depth (PD); bleeding on probing (BoP), and clinical attachment level (CAL). GCF MPO, BGD, and NE levels were determined by means of an enzyme-linked immunosorbent assay (ELISA). Results: PI, GI, and BoP were significantly increased in the Sm group (p < 0.05). PD and CAL showed no significant difference between Sm and n-Sm groups (p > 0.05). In GCF, MPO, BGD, and NE levels were significantly increased in Sm group (p < 0.05). NE levels showed a significant correlation with GI and BoP (p < 0.05 for both). Moreover, a positive correlation between BGD and NE levels (p < 0.05) was measured. Conclusions: It may be concluded that, even in young patients, tobacco consumption affects the host’s immune response related to gingival inflammation. It is, therefore, mandatory to inform young patients about the risk related to tobacco consumption for their gingival health.

[Periodontitis-therapy of a widespread disease]

Parodontitis ist eine chronisch entzündliche nichtübertragbare Erkrankung, die alle Anteile des Zahnhalteapparates (Parodonts) betrifft und dort weitgehend irreversible Schäden verursacht. Schätzungen legen nahe, dass in Deutschland ca. 10 Mio. Menschen an einer schweren Parodontitis erkrankt sind. Parodontitis zeigt über viele Jahre zumeist wenige oder nur milde Symptome, die von den Patienten oft nicht wahrgenommen oder richtig eingeordnet werden. Fehlendes Bewusstsein kann dazu führen, dass zahnärztliche Behandlung erst in einem fortgeschrittenen Erkrankungsverlauf in Anspruch genommen wird, wenn umfangreiche Therapiemaßnahmen notwendig geworden sind und sich die Prognose für den Erhalt der Zähne verschlechtert hat. Der parodontale Screeningindex (PSI) ist ein einfaches und schnelles Instrument, mit dem die Notwendigkeit weiterführender diagnostischer Maßnahmen beurteilt werden kann. Der Index wird mittlerweile bei vielen Patienten durchgeführt. Trotzdem bleiben die Versorgungszahlen niedrig und hinter dem zurück, was für das Absenken der bestehenden Parodontitislast notwendig wäre. Jede Zahnarztpraxis muss in der Lage sein, Parodontitistherapie umzusetzen. Fachzahnärzte oder Spezialisten können die allgemeinzahnärztlichen Kollegen wesentlich bei der Behandlung von schweren Formen von Parodontitis unterstützen. Dazu ist eine Aufwertung des Faches in der universitären Ausbildung erforderlich, aber auch die zunehmende postgraduale Ausdifferenzierung von Spezialisten oder Fachzahnärzten für Parodontologie. Die neuen Behandlungsrichtlinien für die Parodontaltherapie (PAR-Therapie) erlauben die Versorgung der parodontal erkrankten Patienten auf Basis international anerkannter wissenschaftlicher Standards und verbessern damit die Rahmenbedingungen für die Parodontitistherapie in der zahnärztlichen Praxis.

Engaging a polylactide copolymer in oral tissue regeneration: first validation of Suprathel® for guided epithelial and osseous healing

The present study investigated the capacity of Suprathel^® (a copolymer membrane, so far validated for skin regeneration) to also regenerate oral tissue – mucosa and bone, by comparing this biomaterial, in a split-mouth rabbit model, to Mucoderm^®, a xenogeneic collagen matrix certified for keratinized oral mucosa healing. The clinical reason behind this experimental animal model was to determine whether the benefits of this advanced skin regeneration product (Suprathel^®) could be conveyed for future evaluation in clinical trials of oral tissue regeneration in humans. The outcomes of this study validated the use of Suprathel^®, a terpolymer of polylactide with trimethylene carbonate and ε-caprolactone, for stimulation of oral epithelium and alveolar bone regeneration in rabbits. Both Suprathel^® and Mucoderm^® exhibited comparable results and the null hypothesis stating a comparable regenerating effect of these two materials could not be rejected.

Prevalence and antimicrobial susceptibility of Gram-negative bacilli in subgingival biofilm associated with periodontal diseases

BACKGROUND

This cross-sectional study aimed to determine the prevalence and antimicrobial susceptibility of Gram-negative bacilli (GNB) isolated from subgingival biofilm of individuals with different periodontal conditions.

METHODS

Subgingival biofilm was obtained from 362 individuals with periodontal health (PH) (n = 83), gingivitis (n = 74), and periodontitis (n = 205), cultivated in broth and selective media. Isolated strains were identified by mass spectrometry. Antimicrobial susceptibility was determined by the Clinical and Laboratory Standards Institute disk diffusion guidelines. Production of extended-spectrum beta-lactamase (ESBL) and carbapenemases were evaluated by double disk synergy test and spectrophotometric detection of imipenem hydrolysis, respectively. ESBL and carbapenemase encoding genes were surveyed by Polymerase chain reaction (PCR). Differences among groups were examined by Chi-square, Kruskal-Wallis or Mann-Whitney tests.

RESULTS

GNB were isolated from 36.2% of all subgingival biofilm samples, with a significantly greater prevalence and species diversity (P < 0.001) in patients with periodontitis (45.9%) compared with individuals with PH (24.1%) and gingivitis (22.9%). Pseudomonas aeruginosa (27.5%), Enterobacter cloacae (16.8%), and Enterobacter asburiae (10.7%) were the most predominant species. Resistance/reduced sensitivity to at least 1 antimicrobial was detected in 60% of the strains, but only 4.6% were multidrug resistant. Serratia marcescens, E. cloacae, and Enterobacter kobei presented high rates of intrinsic resistance (>40%) to amoxicillin-clavulanate and first/second-generations of cephalosporins. One strain of Klebsiella pneumoniae isolated from periodontitis was resistant to imipenem, but no ESBL encoding genes or ESBL phenotype was detected.

CONCLUSION

High prevalence and diversity of GNB, with low susceptibility to β-lactams are observed in the subgingival microbiota associated with periodontitis.

Pain assessment and analgesic consumption after nonsurgical periodontal therapy

Background:

The aim of this cross-sectional study was to assess the analgesic consumption and the frequency and intensity of pain after nonsurgical periodontal therapy, as well as to associate these factors with the extent and severity of periodontitis and with the degree of anxiety before the procedure.

Materials and Methods:

Fifty-one patients with chronic periodontitis were recruited. The degree of previous anxiety was assessed with the dental anxiety scale questionnaire. Periodontal data were obtained by means of clinical examination and circumferential probing performed by undergraduate students, supervised by a clinical lecturer. The teeth submitted to treatment in the session were registered. Analgesic consumption was recorded 7 days after periodontal intervention. To measure pain, a visual analog scale was used. The patient was instructed to record the pain intensity at 2, 4, 8, 24, and 48 h after subgingival scaling. Differences in pain intensity between periods after nonsurgical periodontal therapy were performed using Anova test. P < 0.05 was statistically significant.

Results:

There was no relevant difference between groups in all variables used in the study (P > 0.05). The use of analgesics was significantly more frequent among individuals who had reported higher levels of pain. The degree of anxiety before treatment was similar among groups (P > 0.05). Most individuals reported no pain or mild pain (P < 0.05).

Conclusion:

Nonsurgical periodontal therapy is associated with low pain or absent pain.

The PorX/PorY system is a virulence factor of Porphyromonas gingivalis and mediates the activation of the type IX secretion system

PorX/PorY is a two-component system (TCS) of Porphyromonas gingivalis that governs transcription of numerous genes including those encoding a type IX secretion system (T9SS) for gingipain secretion and heme accumulation. Here, an in vitro analysis showed that the response regulator PorX specifically bound to two regions in the promoter of porT, a known PorX-regulated T9SS gene, thus demonstrating that PorX/PorY can directly regulate specific target genes. A truncated PorX protein containing the N-terminal receiver and effector domains retained a wild-type ability in both transcription regulation and heme accumulation, ruling out the role of the C-terminal ALP domain in gene regulation. The PorX/PorY system was the only TCS essential for heme accumulation and concomitantly responded to hemin to stimulate transcription of several known PorX-dependent genes in a concentration-dependent manner. We found that PorX/PorY activated the sigH gene, which encodes a sigma factor known for P. gingivalis adaptation to hydrogen peroxide (H₂O₂). Consistently, both ΔporX and ΔsigH mutants were susceptible to H₂O₂, suggesting a PorX/PorY-σ^H regulatory cascade to confer resistance to oxidative stress. Furthermore, the ΔporX mutant became susceptible to high hemin levels that could induce oxidative stress. Therefore, a possible reason why hemin activates PorX/PorY is to confer resistance to hemin-induced oxidative stress. We also demonstrated that PorX/PorY was essential for P. gingivalis virulence because the ΔporX mutant was avirulent in a mouse model. Specifically, this TCS was required for the repression of proinflammatory cytokines secreted by dendritic cells and T cells in the P. gingivalis–infected mice.

Maintaining a protective state for human periodontal tissue

Periodontitis, caused by infection with periodontal pathogens, is primarily characterized by inflammatory bone resorption and destruction of connective tissue. Simply describing periodontitis as a specific bacterial infection cannot completely explain the various periodontal tissue destruction patterns observed. Periodontal tissue damage is thought to be caused by various factors. In recent years, research goals for periodontal pathogens have shifted from searching for specific pathogens to investigating mechanisms that damage periodontal tissues. Bacteria interact directly with the host in several ways, influencing expression and activity of molecules that evade host defenses, and destroying local tissues and inhibiting their repair. The host's innate and acquired immune systems are important defense mechanisms that protect periodontal tissues from attack and invasion of periodontal pathogens, thus preventing infection. Innate and acquired immunity have evolved to confront the microbial challenge, forming a seamless defense network in periodontal tissues. In the innate immune response, host cells quickly detect, via specialized receptors, macromolecules and nucleic acids present on bacterial cell walls, and this triggers a protective, inflammatory response. The work of this subsystem of host immunity is performed mainly by phagocytes, beta-defensin, and the complement system. In addition, the first line of defense in oral innate immunity is the junctional epithelium, which acts as a physical barrier to the entry of oral bacteria and other nonself substances. In the presence of a normal flora, junctional epithelial cells differentiate actively and proliferate apically, with concomitant increase in chemotactic factor expression recruiting neutrophils. These immune cells play an important role in maintaining homeostasis and the protective state in periodontal tissue because they eliminate unwanted bacteria over time. Previous studies indicate a mechanism for attracting immune cells to periodontal tissue with the purpose of maintaining a protective state; although this mechanism can function without bacteria, it is enhanced by the normal flora. A better understanding of the relationship between the protective state and its disruption in periodontal disease could lead to the development of new treatment strategies for periodontal disease.

LuxS quorum sensing system and biofilm formation of oral microflora: A short review article

The LuxS quorum sensing system is considered as the main system that most of the oral bacteria use to communicate in order to create biofilms. Here we identified 11 of the most important biofilm formers that utilize the LuxS system and presented current and recent information regarding this system. Though different bacterial species are able to communicate thorough the LuxS system, it was also found that cross kingdom communication can occur between bacteria and fungi and bacteria and epithelial cells. Immune response also plays and important role in mitigating the effects of biofilms. Here we identified 6 of the most important molecules that are involved in the immune response to biofilms. These immune molecules maintain the stability in the oral cavity by preventing bacteria from overwhelming the space and simultaneously minimizing the immune response in order not to cause tissue damage. Here we also discuss current research being done in order to maintain the balance in the oral cavity via inhibiting biofilm formation without eradicating oral bacteria in order to prevent the overgrowth of other organisms such as Candida albicans. One approach being used is inhibiting AI-2 intermediates which leads to lack of quorum sensing communication between bacteria through the use of intermediate analogues. Another approach that found success is the utilization of D forms of sugars where D-ribose and D-galactose have been proven to inhibit the LuxS system and subsequently preventing the process of quorum sensing leading to the reduction in biofilm formation.

Relationship between Tooth Loss and the Medications Used for the Treatment of Rheumatoid Arthritis in Japanese Patients with Rheumatoid Arthritis: A Cross-Sectional Study

Background: There is limited information regarding the association between tooth loss and the medications used for the treatment of rheumatoid arthritis (RA). Here, we examined the association between tooth loss, disease severity, and drug treatment regimens in RA patients. Method: This study recruited 94 Japanese patients with RA. The severity of RA was assessed using the Steinbrocker classification of class and stage. Data on RA medications were obtained from medical records. We examined the associations between tooth loss, RA severity, and drug treatment regi mens using multinomial logistic regression analyses. Results: Patients with 1–19 teeth had significantly higher odds ratios (ORs) of taking methotrexate (MTX) (OR, 8.74; 95% confidence interval (CI), 1.11–68.8) and biologic disease-modifying antirheumatic drugs (bDMARDs) (OR, 21.0; 95% CI, 1.3–339.1) compared to those with 27–28 teeth when adjusted for RA severity (class). Furthermore, patients with 1–19 teeth had significantly higher ORs of taking MTX (OR, 9.71; 95% CI, 1.22–77.1) and bDMARDs (OR, 50.2; 95% CI, 2.55–990.6) compared to those with 27–28 teeth when adjusted for RA severity (stage). Conclusion: RA patients with fewer teeth were more likely to take stronger RA therapies, independent of RA severity and other factors.

Periodontitis is associated with cardiovascular diseases: A 13-year study

AIM

To prospectively evaluate the association between periodontitis and the incidence of cardiovascular diseases (CVDs) in Thai adults.

MATERIALS AND METHODS

Medical data from the questionnaires and physical examinations of 1850 participants aged 47-73 years from EGAT study were gathered. Random half-mouth periodontal examination of each participant was performed by calibrated periodontists, and periodontal status was defined. The incidence of new CVD events, including coronary heart disease (CHD) and stroke, was verified by cardiologists. The Cox proportional hazard regression model was used to estimate hazard ratios (HRs).

RESULTS

The prevalence of no/mild, moderate and severe periodontitis in the study participants was 11.7%, 52.7% and 35.6%, respectively. During the 13-year follow-up, CVD events occurred in 110 (5.9%) participants, with 82 (4.4%) from CHD and 28 (1.5%) from stroke. After adjusting for cardiovascular risk factors, a significant association between severe periodontitis and the incidence of CHD was found compared with the no/mild periodontitis group with an HR of 4.53 (95% confidence intervals: 1.08-19.02). However, no significant association was seen when considering total CVD events and stroke outcome.

CONCLUSIONS

This study demonstrates that severe periodontitis is associated with an increased incidence of CHD, independent of established cardiovascular risk factors.

Internet of Things—A Novel Innovation in Dentistry

We are living in an era where medicine and dentistry are evolving. Dental caries, tooth malalignment and periodontal diseases are being encountered by dental specialists in their daily practices. New digital technologies are emerging in dentistry for diagnostic and treatment purposes. Digitization enhances our efficiency and saves time. One of the recent smart technological innovation in healthcare field is the Internet of Things (IoT). IoT consists of a network of physical gadgets embedded with instrumentation electronics, mounted chips and sensors. Through cloud web technology and internet connectivity, the required data collection is enabled. Acquired data is then exchanged to the doctors and analysis is done. This review article deals about the concept of IoT and its futuristic role in dentistry. The review article is based on the electronic searching and analysis of various international and national publications on the IoT concept in dentistry, medicine and biomedical engineering. A bench marking analysis was made on various applications, pros and cons of IoT in dentistry. IoT will play a paramount role in the clinical advancement aspects of diagnosis and management of various oral diseases in the forthcoming decades.

Cytokines and Their Genetic Polymorphisms Related to Periodontal Disease

Periodontal disease (PD) is a chronic inflammatory disease caused by the accumulation of bacterial plaque biofilm on the teeth and the host immune responses. PD pathogenesis is complex and includes genetic, environmental, and autoimmune factors. Numerous studies have suggested that the connection of genetic and environmental factors induces the disease process leading to a response by both T cells and B cells and the increased synthesis of pro-inflammatory mediators such as cytokines. Many studies have shown that pro-inflammatory cytokines play a significant role in the pathogenesis of PD. The studies have also indicated that single nucleotide polymorphisms (SNPs) in cytokine genes may be associated with risk and severity of PD. In this narrative review, we discuss the role of selected cytokines and their gene polymorphisms in the pathogenesis of periodontal disease.

Association of Polymorphism in IL-18 Gene with Periodontitis in Uyghur Adults in Xinjiang and Evidence from Six Case-Control Studies with a Comprehensive Analysis

AIM

The aim of the study was to evaluate the association of IL-18 137 G > C, 607 C > A gene polymorphism in Uyghur population with chronic periodontitis (CP) and combine the results with the meta-analysis.

METHODS

In a case-control study, 200 cases with CP and 100 healthy controls were recruited; IL-18 137 G > C, 607 C > A genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). In the meta-analysis, we used electronic databases, including CNKI, Wan Fang, PubMed, EMBASE databases etc.to obtain relevant research published through June 2020. Studies were considered eligible if odds ratios (ORs) and 95% confidence intervals (95% CI) were provided or calculated from the given data. The size of the combined effect was calculated using STATA 15.0.

RESULTS

Our study revealed significant association between CP and IL-18 137 G > C (P = .045, OR = 1.67), 607 C > A (P = .045, OR = 1.67). The overall meta-analysis revealed significant associations between IL-18 137 G > C polymorphism and CP risk in Allele, dominant, co-dominant and recessive genetic models. The subgroup analysis also showed a significant association between the IL-18 137 G > C and risk for periodontitis and aggressive periodontitis in the Asian (GC+ CC VS. GG: P = .047, OR = 1.64,95%CI = 1.01-2.68).

CONCLUSIONS

IL-18 137 G > C, 607 C > A could be associated with susceptibility to periodontitis in Uyghur population. Further case-control of candidate genes studies targeting larger sample sizes and different ethnic groups are needed to arrive more accurate conclusions.

Silencing matrix metalloproteinase-13 (Mmp-13) reduces inflammatory bone resorption associated with LPS-induced periodontal disease in vivo

OBJECTIVES

The aim of this study was to evaluate the effect of specific inhibition of MMP-13 on inflammation and inflammatory bone resorption in a murine model of lipopolysaccharide (LPS)-induced periodontitis.

MATERIALS AND METHODS

Periodontitis was induced in mice by micro-injections of LPS into the gingival tissues adjacent to the palatal surfaces of maxillary molars twice a week for 15 days. Matrix metalloproteinase-13 (Mmp-13) shRNA or a specific biochemical inhibitor were also injected into the same sites in alternating days with the LPS injections. Efficacy of shRNA-mediated silencing of Mmp-13 was verified by quantitative real-time polymerase chain reaction (qPCR) and immunoblot. Bone resorption was assessed by microcomputed tomography (uCT). Histological sections stained with hematoxylin/eosin (H/E) were used in the stereometric analysis of the inflammatory infiltrate. Gingival tissues were used to evaluate expression of Mmp-13, Il-6, Tnf-α, Ptgs2, and Rankl (qPCR). Protein levels of TGF-β and IL-10 in the tissues were determined by enzyme-linked immunosorbent assays (ELISA) or by MMP-13 and p38 immunoblot.

RESULTS

Silencing Mmp-13 expression reduced bone resorption significantly. Expression of Mmp-13, Il-6, and Tnf-α, as well as the protein levels of IL-6 and TNF-α, was reduced in the animals treated with adenovirus-delivered shRNA; however, these effects were not associated with modulation of p38 MAPK signaling. Interestingly, inhibition Mmp-13 did not affect the severity of inflammatory infiltrate.

CONCLUSIONS

Site-specific inhibition of MMP-13 reduced bone resorption and production of inflammatory mediators associated with periodontal disease.

CLINICAL RELEVANCE

The results suggest that site-specific inhibition of MMP-13 may be an interesting strategy to modulate inflammation and reduce bone resorption in osteolytic inflammatory diseases.

Association of periodontitis with leukocyte telomere length in US adults: A cross-sectional analysis of NHANES 1999 to 2002

BACKGROUND

This study examines the association of periodontitis with telomere length (TL) and effect modification by population characteristics.

METHODS

We analyzed data from 3,478 participants from the 1999 to 2002 National Health and Nutrition Examination Survey. Probing depth, attachment loss, and bleed on probing (BOP, available for 1,973 participants only) were examined on the distal, mesial, or mid-facial site of each tooth in two randomly selected quadrants. We defined periodontitis severity according to the Centers for Disease Control/American Academy of Periodontology guideline. TL from leukocytes was measured with qPCR. We used linear and logistic regression to examine the adjusted association of different severity of periodontitis and BOP with continuous TL (bp) and dichotomized short TL (<median), respectively. To assess effect modification, we stratified the analyses by a priori selected population characteristics including sex, age, body weight status, smoking, and cardiometabolic comorbidity.

RESULTS

Moderate BOP (<10% bleeding sites) was significantly associated with a shorter continuous TL (β = -89.0, SE = 37.8). Moderate to severe periodontitis was significantly associated with 47% (95% confidence interval [IL], 1.04 to 2.09) higher odds of shorter TL, compared with those with mild or no periodontitis. The association was stronger in those who were female (adjusted OR, 1.76; 95% CI, 1.10 to 2.83), overweight or obese (adjusted OR, 1.64; 95% CI, 1.12 to 2.41), or had cardiometabolic comorbidities (adjusted OR, 2.13; 95% CI, 1.38 to 3.29).

CONCLUSIONS

Periodontitis was associated with TL, a biomarker of cellular aging. The association was stronger in females, overweight or obese, or those with cardiometabolic diseases. Treatment on periodontitis could potentially protect individuals from aging-related diseases.

Differential immune cell infiltrations between healthy periodontal and chronic periodontitis tissues

Background

Host immunity plays an important role against oral microorganisms in periodontitis.

Methods

This study assessed the infiltrating immune cell subtypes in 133 healthy periodontal and 210 chronic periodontitis tissues from Gene Expression Omnibus (GEO) datasets using the CIBERSORT gene signature files.

Results

Plasma cells, naive B cells and neutrophils were all elevated in periodontitis tissues, when compared to those in healthy controls. In contrast, memory B cells, resting dendritic, mast cells and CD4 memory cells, as well as activated mast cells, M1 and M2 macrophages, and follicular helper T cells, were mainly present in healthy periodontal tissues. Furthermore, these periodontitis tissues generally contained a higher proportion of activated CD4 memory T cells, while the other subtypes of T cells, including resting CD4 memory T cells, CD8 T cells, follicular helper T cells (T_FH) and regulatory T cells (Tregs), were relatively lower in periodontitis tissues, when compared to healthy tissues. The ratio of dendritic and mast cells and macrophages was lower in periodontitis tissues, when compared to healthy tissues. In addition, there was a significant negative association of plasma cells with most of the other immune cells, such as plasma cells vs. memory B cells (γ = − 0.84), plasma cells vs. resting dendritic cells (γ = − 0.64), plasma cells vs. resting CD4 memory T cells (γ = 0.50), plasma cells versus activated dendritic cells (γ = − 0.46), plasma cells versus T_FH (γ = − 0.46), plasma cells versus macrophage M2 cells (γ = − 0.43), or plasma cells versus macrophage M1 cells (γ = − 0.40), between healthy control and periodontitis tissues.

Conclusion

Plasma cells, naive B cells and neutrophils were all elevated in periodontitis tissues. The infiltration of different immune cell subtypes in the periodontitis site could lead the host immunity against periodontitis.

Non-surgical Periodontal Treatment Restored the Gut Microbiota and Intestinal Barrier in Apolipoprotein E-/- Mice With Periodontitis

Periodontitis has been associated with a variety of systematic diseases via affecting gut microbiota. However, the influence of periodontal treatment on intestinal microbiota is not known. Hyperlipidemia can significantly alter gut microbiota structure. It is proposed that the presence of hyperlipidemia can influence the impact of periodontitis on microbiota. This study was conducted to explore the influence of periodontitis and periodontal treatment on the gut microbiota on the basis of hyperlipidemia. Apolipoprotein E^-/-(ApoE^-/-) mice were ligatured to induced periodontitis and non-surgical periodontal treatment was performed for half of them after 4 weeks of ligation. Microbiota communities in the feces collected at 4, 5, 8 weeks after ligation were investigated using next-generation sequencing of 16S rDNA. Bone loss at periodontitis sites were analyzed using micro-computed tomography (Micro-CT). Morphology and mucosal architecture injury of ileum tissue were observed with hematoxylin-eosin staining. The serum lipid levels were assayed. The results showed that β-diversity index in experimental periodontitis group was differed significantly from that of the control group. Significant differences were found in β-diversity between the non-surgical periodontal treatment group and the ligation group. The samples of the non-surgical periodontal treatment group and the control group were clustered together 4 weeks after periodontal treatment. Intestinal villus height and ratio of villus height to crypt depth was found decreased after ligation and restored after non-surgical periodontal treatment. Non-surgical periodontal treatment induced the colonization and prosper of butyrate-producing bacteria Eubacterium, which was absent/not present in the ligation group. We confirmed that periodontitis led to gut microbiota dysbiosis in mice with hyperlipidemia. Non-surgical periodontal treatment had the trend to normalize the gut microbiota and improved the intestinal mucosal barrier impaired by periodontitis in apoE^-/- mice.

The role of the microbiota in periodontal disease

The last decade has witnessed unparalleled advances in our understanding of the complexity of the oral microbiome and the compositional changes that occur in subgingival biofilms in the transition from health to gingivitis and to destructive periodontal disease. The traditional view, which has held sway for the last 2 decades, that disease is characterized by the outgrowth of a consortium, or consortia, of a limited number of potentially pathogenic organisms, has given way to an alternative paradigm. In this new view, the microbiological changes associated with disease represent whole-scale alterations to the overall microbial population structure and to the functional properties of the entire community. Thus, and in common with other microbially mediated diseases of the gastrointestinal tract, the normally balanced, symbiotic, and generally benign commensal microbiome of the tooth-associated biofilm undergoes dysbiosis to a potentially deleterious microbiota. Coincident with progress in defining the microbiology of these diseases, there have been equally important advances in our understanding of the inflammatory systems of the periodontal tissues, their control, and how inflammation may contribute both to the development of dysbiosis and, in a deregulated state, the destructive disease process. One can therefore speculate that the inflammatory response and the periodontal microbiome are in a bidirectional balance in oral health and a bidirectional imbalance in periodontitis. However, despite these clear insights into both sides of the host/microbe balance in periodontal disease, there remain several unresolved issues concerning the role of the microbiota in disease. These include, but are not limited to, the factors which determine progression from gingivitis to periodontitis in a proportion of the population, whether dysbiosis causes disease or results from disease, and the molecular details of the microbial stimulus responsible for driving the destructive inflammatory response. Further progress in resolving these issues may provide significant benefit to diagnosis, treatment, and prevention.

A nomogram prediction for mandibular molar survival in Chinese patients with periodontitis: A 10-year retrospective cohort study

AIMS

To develop a nomogram prediction model of mandibular molar survival by comprehensively analysing clinical and radiographic risk factors of mandibular molar loss.

MATERIALS AND METHODS

Four hundred and seventy-eight mandibular molars of 139 subjects who underwent non-surgical periodontal treatment were examined retrospectively within a mean follow-up period of 11.1 years. The association of risk factors including clinical and radiographic parameters with mandibular molar loss was assessed using univariate and multivariate Cox regression analyses. A nomogram prediction model was developed, and the validation and discriminatory ability of it were analysed.

RESULTS

Hundred and four molars were lost in this study. Probing depth (PD), attachment loss (AL), furcation involvement (FI), bleeding on probing (BOP), tooth mobility and radiographic bone loss were significantly associated with tooth loss (p < .01). A gradient effect of degree of FI on mandibular molar loss existed increasing from degree Ⅱ (HR = 2.37, 95% CI: 1.48, 3.79) to Ⅲ (HR = 5.61, 95% CI: 3.01, 10.45) versus none & degree Ⅰ. The area under the curve (AUC) of the model was 0.891. The calibration curve and decision curve analysis demonstrated good performance and high net benefit of nomogram, respectively.

CONCLUSIONS

A specific nomogram could be adopted to predict the mandibular molar survival and formulate tailored treatment plans in Chinese.

Close Associations of Gum Bleeding with Systemic Diseases in Late Adolescence

BACKGROUND

Though it is well known that periodontal diseases are associated with various systemic diseases in adults, the associations in late adolescents have not been adequately elucidated. We investigated the association between gum bleeding (a major symptom of periodontal diseases) and common systemic diseases in late adolescents: allergic, respiratory, and otorhinolaryngologic diseases.

METHODS

We conducted a retrospective review of the mandatory medical questionnaires administered as a part of legally required freshman medical checkup between April 2017 and April 2019 at the University of Tokyo. Among the total of 9376 sets of responses, 9098 sets from students aged less than 20 were analyzed. An χ2 test and univariate and multivariate binomial logistic regression analyses were performed using SAS ver. 9.4. A value of p < 0.05 was accepted as significant.

RESULTS

According to the questionnaire data, 3321 students (36.5%; 2780 males and 541 females) responded that they experienced gum bleeding whenever they brushed their teeth. These students had significantly higher incidence rates of otitis media/externa and asthma/cough-variant asthma (p = 0.001 and p = 0.006, respectively). The results of the multivariate analysis showed significant rates of the following complications among these students: (1) otitis media/externa (odds ratio (OR) 1.691; 95% confidence interval (CI): 1.193-2.396; p = 0.003), (2) asthma/cough-variant asthma (OR 1.303; 95% CI: 1.091-1.556; p = 0.003), and (3) male gender (OR 1.536; 95% CI: 1.337-1.765; p < 0.001).

CONCLUSIONS

Gum bleeding was closely associated with otitis media/externa and asthma in late adolescents. Our study reinforces new evidence about the association between periodontal diseases and asthma, and it reveals a novel and close association between gum bleeding and otitis media/externa.

Gender Differences in the Levels of Periodontal Destruction, Behavioral Risk Factors and Systemic Oxidative Stress in Ischemic Stroke Patients: A Cohort Pilot Study

Background: Due to the higher frequency of ischemic stroke in men compared to women, we aimed to determine if gender differences exist regarding periodontal status and several plasma biomarkers in patients with a recent large artery atherosclerosis ischemic stroke (IS). Material and methods: Patients with their first IS within less than six weeks who were able to undergo periodontal examinations were evaluated. Demographic data, periodontal status, oxidative stress parameters/plasma antioxidant capacity, and C-reactive protein in patients who suffered a recent large artery atherosclerosis ischemic stroke were reccorded. Results: 93 patients were included in the study. More men were smokers (12/57 vs. 3/36) and consumed alcohol (17/57 vs. 3/36), and more women had higher glycemic values (p = 0.023), total cholesterol (p < 0.001), LDL (low-density lipoprotein)-cholesterol (p = 0.010), and HDL (high-density lipoprotein)-cholesterol (p = 0.005) levels. Significantly more men than women had moderate plus severe periodontal disease (p = 0.018), significantly higher levels of nitric oxide (p = 0.034), and significantly lower levels of total antioxidant capacity (p = 0.028). Conclusions: In this pilot study, men seem to be more prone to oxidative stress and to develop more severe forms of periodontitis among patients with stroke, but the results need validation on a larger sample.

Periodontitis, Low-Grade Inflammation and Systemic Health: A Scoping Review

Background and objectives: Periodontitis is a multifactorial chronic inflammatory infectious disease in which an infection is necessary, but not sufficient, for development of the condition. Individual susceptibility strictly linked to the immune and inflammatory response of the organism must also be present. Low-grade inflammation (LGI) is a systemic status of chronic sub-clinical production of inflammatory factors. This condition represents a risk factor for many chronic diseases including diabetes, cardiovascular disease, cerebrovascular disease, neurodegenerative disease and cancer. This scoping review aims to clarify, summarize and disseminate current knowledge on the possible link between periodontitis, LGI and systemic health. Materials and Methods: PRISMA Extension for Scoping Reviews guidelines were followed. An ad-hoc created keyword string was used to search the electronic databases of PubMed/Medline, Embase, The Cochrane Library and ClinicalTrials.gov. A hand search of specialized journals and their reference lists was also performed. Results: 14 studies that respected eligibility criteria were selected and analyzed. There is emerging evidence of strong links between periodontitis, LGI and systemic health. On the one hand, periodontitis influences the systemic status of LGI and on the other hand, the systemic production of inflammatory factors affects periodontitis with a bidirectional connection. Conclusions: LGI and the subsequent onset of a systemic inflammatory phenotype can be considered the common substrate of many chronic inflammatory diseases including periodontitis, with multiple mutual connections between them. Understanding of the biological principles and mechanisms underlying such a complex interrelationship could lead to significant improvements in the field of personalized diagnostics and therapeutic protocols.

Drinking green tea alleviates alveolar bone resorption in ligature-induced periodontitis in mice

OBJECTIVES

It has been reported that green tea exerts antibacterial, anti-inflammatory, and antioxidant effects. The purpose of the present study was to evaluate the effects of drinking green tea on bone resorption in ligature-induced periodontitis in mice.

METHODS

Sixty C57BL/6 eight-week-old male mice were used. To induce periodontitis, a ligature was placed for 7 days around the upper left second maxillary molar. After ligature removal, the animals were administered different concentrations of green tea (1.5 g/60 mL, 3 g/60 mL, or 6 g/60 mL) or distilled water. At 1 and 2 weeks of administration, the animals were sacrificed and micro-CT images of the maxillae were taken. Next, the depth and area of alveolar bone loss in the buccal and palatal sides were measured. The number of inflammatory cells and osteoclasts in histological sections were counted.

RESULTS

The result showed ligature-induced alveolar bone loss. Green tea inhibited ligature-induced bone loss in the buccal side in a dose-dependent manner. Histologically, ligature increased the number of inflammatory cells and osteoclasts, but this effect was alleviated by green tea.

CONCLUSIONS

Evidence from this animal experiment suggested that drinking green tea would be potentially beneficial to reduce alveolar bone loss in ligature-induced periodontitis.

Prevalence and associated factors of periodontal conditions among 55- to 74-year-old adults in China: results from the 4th National Oral Health Survey

OBJECTIVE

The purpose of this study was to assess periodontal health conditions among 55- to 74-year-old Chinese people and to analyze the factors associated with periodontal diseases.

MATERIALS AND METHODS

In total, 9054 subjects aged 55-74 years were enrolled from all 31 provinces using a stratified multistage probability sampling method, autonomous regions and municipalities of the Chinese mainland, the response rate was 86.9%. All subjects underwent clinical examinations on the severest site for every tooth and completed a questionnaire that collected information on their sociodemographic characteristics and oral habits. T tests, chi-square tests and binary logistic regression analysis were performed to analyze the data.

RESULTS

The percentage of people without bleeding on probing, probing depth ≥ 4 mm and attachment loss > 3 mm was 5.0 and 9.3% in the 55- to 64-year-old and the 65- to 74-year-old age group. The prevalence of bleeding on probing was 88.4% among 55 to 64 years old and 82.6% among 65 to 74 years old. Mean number of teeth with bleeding on probing were 13.87 among 55 to 64 years old and 11.25 among 65 to 74 years old. The prevalence of probing depth ≥ 4 mm and attachment loss > 3 mm were 69.3 and 69.9% in people aged 55-64 years and were 64.6 and 74.2% in people aged 65-74 years. Mean number of teeth with probing depth = 4-5 mm and probing depth ≥ 6 mm were 4.48 and 0.36 in 55-64 age group and 3.70 and 0.33 in 65-74 age group. And mean number of teeth with attachment loss > 3 mm were 5.17 among 55 to 64 years old and 5.63 among 65 to 74 years old. Besides, attachment loss > 3 mm was associated with age, gender, smoking, toothbrushing frequency and toothpick use.

CONCLUSIONS

Periodontitis was not highly prevalent among 55- to 74-year-old Chinese adults. Age, gender, smoking, toothbrushing frequency and toothpick use could be risk factors.

CLINICAL RELEVANCE

Scientific rationale for the study: The periodontal conditions among 55 to 64 and 65 to 74 years old Chinese population were not highly serious, but prevalence of bleeding on probing, periodontal pockets and attachment loss should be drawn enough attention by relevant public health administrations.

PRINCIPAL FINDINGS

The prevalence of periodontal diseases was evaluated in 55- to 64-year-old and 65- to 74-year-old subjects in a nationally representative Chinese sample population. The prevalence of probing depth ≥ 4 mm and AL > 3 mm were high; these values were 69.3% and 69.9%, respectively, in the 55-64 age group and 64.6% and 74.2%, respectively, in the 65-74 age group. In addition, case percentage of AL = 4-5 mm combined with PD < 6 mm were 23.1 and 19.4% among 55- to 64-year-old and 65- to 74-year-old people. And case percentage of AL> 5 mm combined with PD ≥ 6 mm were 11.1% and 12.1% among 55- to 64-year-old and 65- to 74-year-old people, respectively.

PRACTICAL IMPLICATIONS

The present study provides a reference for the epidemiological analysis of periodontal diseases. To reduce widespread inadequate treatment of periodontal diseases, clinical management should be performed in dental practices. Furthermore, oral health recommendations should be made at multiple levels.

Comparison of the effectiveness between power toothbrushes and manual toothbrushes for oral health: a systematic review and meta-analysis

Objective: Power toothbrushes is considered an effective tool for maintaining oral health; however, its efficacy as compared to manual toothbrushes is still not completely clarified. This article aims to evaluate the efficacy of power toothbrushes compared with the manual toothbrushes in terms of plaque, gingivitis and bleeding reduction.Methods: An electronic search was performed on PUBMED, Web of Science, Wiley and Research Gate. Studies comparing the effectiveness of plaque, gingivitis and bleeding reduction between power and manual toothbrushes were included. Results and effect sizes analysis are presented as standard mean difference (SMD), and subgroup analysis stratified by mode of action of the power toothbrush was performed. Study quality and risk of bias were assessed using the Cochrane assessment tool.Results: A total of 21 randomized clinical studies were included. Power toothbrushes were significantly more effective in reducing plaque index (26 trials: SMD = 0.86, 95% CI: 0.58 to 1.14, I² = 91.5%, p < .0001), gingival index (14 trials: SMD = 0.47, 95% CI: 0.12 to 0.82, I² = 88.7%, p < .0001), and bleeding index (11 trials: SMD = 0.92, 95% CI: 0.43 to 1.40, I² = 91.8%, p < .0001) compared with the manual toothbrushes, except that there was no significant differences between the oscillating-rotating toothbrushes and manual toothbrushes regarding gingivitis reduction (7 trials: SMD = 0.07, 95% CI: -0.20 to 0.33, I² = 57.2%, p = .03).Conclusions: Power toothbrushes is more effective in reducing dental plaque, gingivitis and bleeding compared with the manual toothbrush.

Comparative Evaluation of Boric Acid Gel versus Chlorhexidine Gel in the Treatment of Chronic Periodontitis: Randomized, Placebo-Controlled Clinical Study

Background:

Over the years, various antimicrobials have been tried and tested in the treatment of periodontitis. Chlorhexidine (CHX) has emerged as the gold standard. In recent years, trend has shifted toward the use of agents with antibacterial, anti-inflammatory, and osteoblastic activity. Boric acid (BA) is one such agent which possess all such properties and thus been evaluated in the treatment of periodontitis.

Aim and Objective:

The aim of the study is to compare and evaluate the efficacy of 0.75% BA gel versus 1% CHX gel as an adjunct to scaling and root planing in patients with chronic periodontitis both clinically and microbiologically.

Materials and Methods:

The present study was a randomized, placebo-controlled clinical trial where 45 systemically healthy patients with chronic periodontitis were included in the study. About 15 patients each were divided into three groups, that is, Group I received BA gel, Group II received CHX gel, and Group III received placebo gel as a local drug delivery agent. Clinical parameters such as gingival index, plaque index, modified sulcus bleeding index, probing pocket depth, and clinical attachment level were evaluated at baseline and 6-month follow-up. Microbiological analysis to check for mixed anaerobic flora was done using subgingival plaque samples at baseline and 3 months after treatment.

Results:

Significant reduction was seen in all clinical parameters in both BA and CHX gel groups as compared to control group (P < 0.05). However, on comparing BA gel group with CHX gel, the results were statistically insignificant (P > 0.05).

Conclusion:

BA gel and CHX gel both were equally effective in improving the clinical and microbiologic parameters in patients with chronic periodontitis when used as a local drug delivery agent.

Understanding resolution of inflammation in periodontal diseases: Is chronic inflammatory periodontitis a failure to resolve?

Periodontitis is an infectious-inflammatory disease that results from loss of balance between the commensal microbiome and the host response. The hyper-inflammatory, uncontrolled inflammatory immune lesion promotes tissue damage and impedes effective bacterial clearance. In this review, the relationship between the microbiome and the inflammatory/immune response is explored in the context of a bi-directional pathogenesis; bacteria induce inflammation and inflammation modifies the growth environment causing shifts in the composition of the microbiome. Resolution of inflammation is an active, receptor-mediated process induced by specialized pro-resolving lipid mediators. Inflammatory disease may, therefore, be the result of failure of resolution. Failure to resolve inflammation coupled with resultant microbiome changes is hypothesized to drive development of periodontitis. Re-establishment of microbiome/host homeostasis by specialized pro-resolving lipid mediator therapy suggests that microbiome dysbiosis, the host hyperinflammatory phenotype, and periodontitis can be reversed.

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.

Enhancement of periodontal tissue regeneration by conditioned media from gingiva-derived or periodontal ligament-derived mesenchymal stem cells: a comparative study in rats

BACKGROUND

Evidence has demonstrated conditioned medium (CM) from periodontal ligament stem cells (PDLSCs) improved periodontal regeneration. Gingival mesenchymal stem cells (GMSCs) have been considered an alternative strategy for regenerative medicine. To determine whether GMSC-CM could promote periodontal wound healing, we compared the effects of GMSC-CM and PDLSC-CM on periodontal regeneration and the underlying mechanisms in rat periodontal defects.

METHODS

Cell-free CMs were collected from PDLSCs, GMSCs, and gingival fibroblasts (GFs) using ultracentrifugation (100-fold concentration). Periodontal defects were created on the buccal side of the first molar in the left mandible of 90 rats by a surgical method. Collagen membranes loaded with concentrated CMs (α-MEM, GF-CM, GMSC-CM, PDLSC-CM) were transplanted into periodontal defects. After 1, 2, and 4 weeks, the animals were sacrificed and specimens including the first molar and the surrounding tissues were separated and decalcified. Hematoxylin-eosin and Masson's trichrome staining were performed to evaluate periodontal regeneration. Immunohistochemical staining for tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-10 was conducted to analyze inflammation. Immunohistochemistry of BSP-II and Runx2 was performed to analyze osteoblast differentiation.

RESULTS

Histological analysis showed the amount of newly formed periodontal tissue was significantly higher in both the GMSC-CM and PDLSC-CM groups than in the other groups, with no significant difference between these two groups. At 1 and 2 weeks, the expression levels of TNF-α and IL-1β were significantly lower in the GMSC-CM and PDLSC-CM groups than in the other three groups, while there was no significant difference between these two groups. IL-10 expression was significantly higher in the GMSC-CM group than in the PDLSC-CM group and the other three groups. At 1, 2, and 4 weeks, BSP-II and Runx2 expressions were significantly higher in the GMSC-CM and PDLSC-CM groups than in the other three groups, with no significant difference between the two groups.

CONCLUSIONS

Our results demonstrate that GMSC-CM transplantation can significantly promote periodontal regeneration in rats and achieve the same effect as PDLSC-CM. The mechanism of periodontal regeneration may involve the regulation of inflammatory factors and the promotion of osteogenic differentiation of bone progenitor cells in the wound region by CMs from MSCs.

The Role of Bacterial Biofilms in Dental Caries and Periodontal and Peri-implant Diseases: A Historical Perspective

Over the last hundred years, groundbreaking research in oral microbiology has provided a broad and deep understanding about the oral microbiome, its interactions with our body, and how the community can affect our health, be protective, or lead to the development of dental diseases. During this exciting journey, hypotheses were proposed, and concepts were established, discarded, and later revisited from updated perspectives. Dental plaque, previously considered a polymicrobial community of unspecific pathogenicity, is recognized as microbial biofilms with healthy, cariogenic, or periodontopathogenic profiles, resulting from specific ecologic determinants and host factors. The "one pathogen, one disease" paradigm of oral infections has been replaced by a holistic concept of a microbial community as the entity of pathogenicity. Cutting-edge technology can now explore large microbial communities related to different clinical conditions, which has led to finding several novel disease-associated species and potential pathobionts and pathobiomes. This vast amount of data generated over time has widened our view of the etiology of caries and periodontal and peri-implant diseases and has promoted updated strategies to treat and prevent the oral diseases.

Periodontal disease might be a risk factor for graft versus host disease. A systematic review

PURPOSE

The aim of this systematic review was to determine a potential association between periodontal disease and graft versus host disease (GVHD).

DESIGN

PubMed, Scopus and Web of Science databases were searched to identify all relevant articles. The eligibility criteria were prospective, retrospective, cross-sectional, cohort, case-control studies and interventional studies that assessed periodontal parameters in GVHD adults' patients.

RESULTS

Seven studies, published between 2000 and 2018, were eligible. The aggravation of periodontal tissues is due to inadequate oral hygiene, dental plaque, decays, gum recession, retained roots, tooth loss, periodontally infected teeth. Several studies have indicated that periodontitis treatment performed before transplantation showed the reduction of gingival inflammation and maintenance of periodontal health.

CONCLUSIONS

Periodontitis might be a risk factor for GVHD. However, due to the limited number of studies included in the review and their heterogeneity, more data are needed to sustain the correlation between periodontitis and GVHD.

Pressure Cycling Technology Assisted Mass Spectrometric Quantification of Gingival Tissue Reveals Proteome Dynamics during the Initiation and Progression of Inflammatory Periodontal Disease

Understanding the progression of periodontal tissue destruction is at the forefront of periodontal research. The authors aimed to capture the dynamics of gingival tissue proteome during the initiation and progression of experimental (ligature-induced) periodontitis in mice. Pressure cycling technology (PCT), a recently developed platform that uses ultra-high pressure to disrupt tissues, is utilized to achieve efficient and reproducible protein extraction from ultra-small amounts of gingival tissues in combination with liquid chromatography-tandem mass spectrometry (MS). The MS data are processed using Progenesis QI and the regulated proteins are subjected to METACORE, STRING, and WebGestalt for functional enrichment analysis. A total of 1614 proteins with ≥2 peptides are quantified with an estimated protein false discovery rate of 0.06%. Unsupervised clustering analysis shows that the gingival tissue protein abundance is mainly dependent on the periodontitis progression stage. Gene ontology enrichment analysis reveals an overrepresentation in innate immune regulation (e.g., neutrophil-mediated immunity and antimicrobial peptides), signal transduction (e.g., integrin signaling), and homeostasis processes (e.g., platelet activation and aggregation). In conclusion, a PCT-assisted label-free quantitative proteomics workflow that allowed cataloging the deepest gingival tissue proteome on a rapid timescale and provided novel mechanistic insights into host perturbation during periodontitis progression is applied.

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.

Comparison of efficacy of probiotics versus tetracycline fibers as adjuvants to scaling and root planing

Context:

Both gingivitis and periodontitis are due to the detrimental effects of the microbe-laden biofilm. The mainstay of periodontal treatment is, therefore, the disruption of this biofilm by scaling and root planing (SRP). Other treatment protocols such as systemic antimicrobials have been administered as adjuvants after scaling and root planning. However, due to antimicrobial resistance, as well as a shift of the flora from a symbiotic to a dysbiotic one, this mode of treatment has its shortcomings. Thus, local drug delivery has gained prominence as a therapeutic tool.

Aims:

The aim of this study is to compare the efficacy of subgingivally delivered probiotics as a monotherapy, in combination with tetracycline fibers, and tetracycline fibers alone after SRP.

Settings and Design:

This study was a parallel arm, randomized clinical and microbiological study. Thirty patients with chronic periodontitis aged between 20 and 50 years were selected from the outpatient ward of a tertiary referral care hospital in Hyderabad and equally divided into three groups.

Materials and Methods:

This study was conducted from January 2017 to February 2017 and ethical clearance was obtained from the institutional ethical committee.

Statistical Analysis Used:

Mean values and standard deviations were calculated for Plaque Index, Sulcular Bleeding Index (SBI), probing depth (PD), and microbial colony-forming units, for all the three groups at different time intervals. Paired “t-test” was used for intragroup comparison and Student's “t-test” for intergroup comparison. Results were regarded as statistically significant when P < 0.05.

Results:

Intragroup comparison yielded significant improvement in all the variables (P < 0.0001). However, intergroup comparison showed statistically significant differences pertaining to the PD (P < 0.001) and SBI only (P < 0.001), between Group A and Group B and Group B and Group C respectively.

Conclusions:

Group A and Group C showed better results than Group B.

Review of obesity and periodontitis: an epidemiological view

Obesity and periodontitis are among the most common non-communicable diseases, and epidemiological studies report the influence of obesity in the onset and progression of periodontitis. Data indicate that increased body mass index, waist circumference, percentage of subcutaneous body fat, and serum lipid levels are associated with increased risk to develop periodontitis. The underlying biological mechanisms of this association involve adipose tissue-derived cytokines, such as tumour necrosis factor-α and interleukin-6, which affect whole-body metabolism and contribute to the development of a low-grade systemic inflammation. Multiple studies report a positive association between these two diseases across diverse populations. Obesity does not appear to impair the success of periodontal therapy. However, currently available evidence is variable and therefore inconclusive. Despite the limited evidence about recommendations on treatment planning, oral healthcare professionals need to be aware of the complexity of obesity to counsel their patients about the importance of maintaining healthy body weight and performing good oral hygiene procedures.

Proteomic analysis of whole saliva in chronic periodontitis

Periodontitis is a chronic inflammatory disease resulting from a dysbiosis of the dental biofilm and a dysregulated host response in susceptible individuals. It is characterized by periodontal attachment destruction, bone resorption and eventual tooth loss. Salivary biomarkers have been sought to predict and prevent periodontitis. This comparative study analyzed the salivary proteome of individuals with chronic periodontitis (CP) and periodontal health (PH) and correlated specific proteins with clinical parameters of disease by using mass spectrometry. Stimulated whole saliva was obtained 10 PH and 30 CP patients and pooled into 5 healthy control samples and 15 CP samples. After precipitation with TCA, samples were digested enzymatically with trypsin and analyzed by a LTQ Orbitrap Velos equipped with a nanoelectrospray ion source. A wide range of salivary proteins of various functions was significantly reduced in CP individuals, whereas salivary acidic proline-rich phosphoprotein, submaxillary gland androgen-regulated protein, histatin-1, fatty acid binding protein, thioredoxin and cystatin-SA were predominant in diseased patients and correlated significantly with signs of periodontal attachment loss and inflammation. In conclusion, few specific salivary proteins were associated with CP. These findings may contribute to the identification of disease indicators or signatures for the improvement of periodontal diagnosis. SIGNIFICANCE: Periodontitis is a chronic inflammatory disease that results in periodontal attachment destruction, bone resorption and eventual tooth loss. Salivary biomarkers have been sought to predict periodontitis. The analysis of the salivary proteome of individuals with chronic periodontitis indicated that several proteins of various functions were significantly reduced in these individuals, except for salivary acidic proline-rich phosphoprotein, submaxillary gland androgen-regulated protein, histatin, fatty acid binding protein, thioredoxin and cystatin. Differences in salivary proteome profiles between periodontal health and periodontitis may contribute to the identification of disease indicators and to the improvement of periodontal diagnosis and treatment.

Correlation study on mtDNA polymorphisms as potential risk factors in aggressive periodontitis by NGS

OBJECTIVES

Using next-generation sequencing (NGS) to determine whether aggressive periodontitis is associated with specific mitochondrial polymorphisms.

MATERIALS AND METHODS

A total of 165 unrelated Han Chinese were enrolled in the study. We analyzed the mitochondrial DNA (mtDNA) in 97 patients with aggressive periodontitis and 68 healthy controls by NGS. The mitochondrial DNA was L-PCR-amplified and subsequently sequenced by an Illumina Genome Analyzer (NGS). Chi-square tests were used to assess the differences between the two groups. In cases of significant difference, multivariate logistic regression models were further used to analyze the association between mtDNA polymorphisms and aggressive periodontitis.

RESULTS

Significant association was observed between aggressive periodontitis and eight mitochondrial polymorphisms: "8860G-10400C" (OR = 2.828, p = .002), "8701A" (OR = 2.308, p = .005), "12705C-10398A" (OR = 2.683, p = .002), "9540C" (OR = 3.838, p = .001) and "10873T-15043G" (OR = 4.375, p = .001).

CONCLUSIONS

The pathogenesis of aggressive periodontitis is complicated, and its heredity is not well characterized. Our study was the first to use next-generation sequencing and found that 8860G-10400C, 8701A, 12705C-10398A, 9540C, and 10873T-15043G are associated with aggressive periodontitis in the Han Chinese population.

Influence of Periodontal Disease on cardiovascular markers in Diabetes Mellitus patients

The objective of the present study was to establish if individuals with Diabetes Mellitus (DM2) and periodontal diseases (gingivitis or periodontitis) presented an increase in the concentration of modified LDL (moLDL) and what is the influence of periodontal treatment on the decrease of moLDL particles with consequent improvement in the parameters of DM2. Twenty-four diabetic patients with periodontitis (Group 1) and twenty-four diabetic patients with gingivitis (Group 2) were followed up for a period of 12 months. Group 1 was treated with periodontal debridement, and Group 2 received supra-gingival scaling and prophylaxis. In both groups, periodontal clinical parameters: probing depth (PD), clinical attachment level (CAL), gingival resection (GR), bleeding on probing index (BOP) and plaque index; inflammatory serum markers (glycemia, A1c, total cholesterol, HDL-cholesterol (HDL-c), LDL-cholesterol (LDL-c), triglycerides and hs-CRP) and oxidized LDL (oxLDL) were measured at baseline, t = 6 and t = 12 months after treatment. Solutions of LDL were analyzed using the nonlinear optical Z-Scan and optical absorption techniques. The periodontal clinical parameters showed significant improvement (p < 0.05) in both Group after 12 months. For both groups, total cholesterol, HDL-c, LDL-c, triglycerides and A1c levels did not show significant reductions after periodontal therapy. hs-CRP levels in Group 1 presented a significant reduction after 12 months. The glycemic rate and the oxLDL concentrations did not show significant differences as a function of time. The optical measurements of LDL solutions revealed an improvement of the LDL-c quality in both groups. Periodontal debridement was able to improve periodontal parameters and the quality of LDL-c in diabetic patients but without changes in the oxLDL concentration in both groups. Considering the clinical relevance, the reduction of infectious and inflammatory sites present in the oral cavity through periodontal therapy may help with the control and prevention of hyperglycemia and precursors of cardiovascular diseases.

Evidence-based strategy for dental biofilms: Current evidence of mouthwashes on dental biofilm and gingivitis

Therapeutic mouthwash (MW) is an adjunctive tool along with a regular oral hygiene routine of daily tooth brushing and daily flossing. Previous systematic reviews have demonstrated that it is effective against dental biofilm and gingival inflammation, for prevention of dental caries, and for managing one's bad breath condition according to the active ingredients. MWs prevent the microorganisms from bacterial adhesion that corresponds to the initial step in biofilm formation. This review summarized the current state of evidence such as anti-biofilm, anti-gingivitis and cariostatic properties of MWs by evaluating systematic reviews from the past six years. The anti-biofilm property has been proven to be effective, with strong evidence of three main clinical efficacies. The most commonly studied active agent was chlorhexidine gluconate (CHX), followed by essential oil (EO) and cetylpyridinium chloride. All the systematic reviews are in complete agreement that CHX and EO provide statistically significant improvements in terms of plaque and gingival indices. These effects have held up over the years as the number of studies has increased. While the use of fluoride MW is proven to be effective in improving the oral health of both children and adults, the quality of evidence is still regarded as low.