Contemporary educational methods in periodontology.

AIM: The 1st European Workshop on Periodontal Education in 2009 made recommendations regarding the scope of periodontal education at undergraduate (UG), postgraduate (PG) and continuing professional development (CPD) levels, defining competencies and learning outcomes that were instrumental at the time in helping to define periodontal teaching curricula. The 19th European Workshop on Periodontology and 2nd European Consensus Workshop on Education in Periodontology (Education in Periodontology in Europe) was held in 2023 to identify changes and future developments in periodontal education (including those informed by the COVID-19 pandemic) and embracing methods and formats of periodontal teaching and training. The aim of this review was to assess current knowledge regarding education methods in periodontology, including traditional face-to-face (F2F) teaching and the move to student-centred methods, virtual learning methods and use of digital technology, as well as blended teaching and learning (including teaching delivery and assessment) at UG, PG and CPD levels. MATERIALS AND METHODS: Systematic searches were conducted to identify relevant studies from the literature. Data were extracted and descriptive summaries collated. RESULTS: The pandemic was a major disruptor of traditional F2F teaching but provided opportunities for rapid implementation of alternative and supplementary teaching methods. Although online learning has become an integral part of periodontal education, teachers and learners alike favour some form of F2F teaching. Blended teaching and learning are feasible in many areas of periodontal education, both for knowledge and skills acquisition as well as in assessment. Student-centred methods and blended approaches such as the flipped classroom seem highly effective, and online/virtual classrooms with both synchronous and asynchronous lectures are highly valued. Learning with haptic methods and virtual reality (VR) enhances the educational experience, especially when VR is integrated with traditional methods. The quality of the teacher continues to be decisive for the best knowledge transfer in all its forms. CONCLUSIONS: Live F2F teaching continues to be highly trusted; however, all types of student-centred and interactive forms of knowledge transfer are embraced as enhancements. While digital methods offer innovation in education, blended approaches integrating both virtual and traditional methods appear optimal to maximize the achievement of learning outcomes. All areas of periodontal education (UG, PG and CPD) can benefit from such approaches; however, more research is needed to evaluate their benefits, both for knowledge transfer and skills development, as well as in assessment.

Upregulation of psoriasin/S100A7 correlates with clinical severity in patients with oral lichen planus.

OBJECTIVES: The aim of this study was to: (1) investigate the expression patterns of antimicrobial peptides (AMPs), specifically psoriasin (S100A7) and calgranulin A and B (S100A8/A9), in patients with oral lichen planus (OLP) compared to healthy individuals; (2) evaluate the oral health-related quality of life (OHrQoL) in OLP patients versus healthy controls; (3) investigate the impact of clinical severity of OLP on OHrQoL; and (4) assess the influence of AMP expression on clinical severity and OHrQoL in OLP patients. MATERIALS AND METHODS: Oral mucosal biopsies (n = 38) were collected from healthy individuals (n = 17) and patients with OLP (n = 21). Levels of AMPs (S100A7, S100A8, S100A9) and pro-inflammatory cytokines interleukin-8 (IL-8) and tumor necrosis factor alpha (TNFα) were assessed by RT-qPCR. AMP protein localization was identified by indirect immunofluorescence analysis. OHrQoL was assessed using the OHIP-G14 questionnaire, and clinical severity was evaluated with the Oral Disease Severity Score (ODSS). Correlations between OLP manifestation, OHrQoL, and AMP expression were evaluated. RESULTS: (1) S100A7 (p < 0.001), IL-8 (p < 0.001), and TNFα (p < 0.001) mRNA levels were significantly upregulated in OLP tissue compared to healthy tissue, while S100A8 (p < 0.001) and S100A9 (p < 0.001) mRNA levels were downregulated. Immunofluorescence staining revealed an enhanced expression of S100A7 and decreased protein expression of S100A9 in OLP tissue. (2) OLP patients (9.58 ± 8.32) reported significantly higher OHIP-G14 scores compared to healthy individuals (0.67 ± 0.87; p < 0.001), particularly in the categories "physical pain" (p < 0.001) and "psychological discomfort" (p = 0.025). (3,4) Clinical severity (25.21 ± 9.77) of OLP correlated positively with OHrQoL (ρ = 0.497) and psoriasin expression (ρ = 0.402). CONCLUSIONS: This study demonstrated differential expression patterns of AMPs in OLP and highlighted the correlation between the clinical manifestation of OLP and OHrQoL. Further research approaches should address the role of psoriasin in the risk of malignant transformation of OLP. CLINICAL RELEVANCE: Psoriasin is a putative biomarker to monitor disease severity including malignant transformation of OLP lesions. OHIP-G14 scores can be useful to monitor OHrQoL in OLP patients.

Evaluation of acceptance and preference of topical lidocaine application versus articaine injection anesthesia after nonsurgical periodontal treatment: A randomized clinical trial.

BACKGROUND: To compare acceptance and preference of topical lidocaine gel anesthesia with articaine injection anesthesia in patients with moderate periodontitis undergoing scaling and root debridement. METHODS: Ninety-one patients completed this randomized multicenter split-mouth controlled study and underwent two separate periodontal treatment sessions on different days, one with a topical intrapocket lidocaine gel application and the other with an articaine injection anesthesia in a different order depending on randomization. Parameters measured were the patients' preference for topical lidocaine gel anesthesia or injection anesthesia with articaine (primary efficacy criterion), their maximum and average pain, and their intensity of numbness as well as experience of side effects; the probing depth; and the dentists' preference and their evaluations of handling/application, onset and duration of anesthetic effect, and patient compliance. RESULTS: After having experienced both alternatives, 58.3% of the patients preferred the topical lidocaine gel instillation into the periodontal pockets. The safety profile of the lidocaine gel differed positively from the safety profile of articaine injection in type and frequency of adverse drug reactions. The dentists' acceptance and preference regarding either anesthetic method studied were balanced. CONCLUSIONS: Instillation of lidocaine gel into the periodontal pocket is a preferred alternative to injection anesthesia for most of the patients and an equivalent alternative for dentists in nonsurgical periodontal therapy.

TYK2 inhibition with deucravacitinib ameliorates erosive oral lichen planus.

Erosive oral lichen planus (OLP) is a challenging disease. This T cell driven disorder frequently shows a treatment unresponsive course and strongly limits patients' quality of life. The disease lacks FDA or EMA approved drugs for its treatment and the efficacy of the commonly administered treatments (i.e. topical and systemic steroids, steroid sparing agents) is often only partial. Although the etiopathogenesis of the disease still needs to be fully elucidated, recent advances helped to identify interferon-É£ (IFN-É£) as a pivotal cytokine in OLP pathogenesis, thus making the interference with its signalling a therapeutic target. Janus kinase (JAK) inhibitors therefore gained relevance for their inhibitory effect on IFN-É£ signalling. While some drugs such as abrocitinib, upadacitinib, tofacitinib directly interfere with IFN-É£ signalling through blockade of JAK1 and/or JAK2, deucravacitinib, a selective TYK-2 inhibitor indirectly interferes on IFN-É£ activation through interference with interleukin (IL)-12, a potent promotor for Th1/IFN-É£ responses. This mechanism of action makes deucravacitinib a candidate drug for the treatment of OLP. Here we provide initial evidence that deucravacitinib 6 mg daily has a beneficial effect in three patients with oral OLP.

The role of viruses in oral mucosal lesions.

The mucosa of the oral cavity is exposed to a large number of different microorganisms such as archaea, bacteria, fungi, parasites, and viruses. Among those, viruses cause specific infections, which can easily be transmitted from one person to another. The infectious route may not only include patients and their relatives but also the dental professional team. Thus, a wide knowledge regarding specific viral infections is crucial for the daily routine. Signs and symptoms of oral viral infections can be completely absent or develop into a pronounced clinical picture, so that early detection and information determine the further course of the infection and its influence on other inflammatory diseases, such as periodontitis, as well as the safety of family members and the social environment. As the clinical manifestation of viral infections may be highly variable leading to heterogenous mucosal lesions it is, in most cases, mandatory to differentiate them by specific microbiological tests in addition to clinical examination procedures. This article will give an overview of the role of viruses infecting the oral mucosa, and in addition, describe their clinical manifestation and management.

A genome-wide association study meta-analysis in a European sample of stage III/IV grade C periodontitis patients ≤35 years of age identifies new risk loci.

AIM: Few genome-wide association studies (GWAS) have been conducted for severe forms of periodontitis (stage III/IV grade C), and the number of known risk genes is scarce. To identify further genetic risk variants to improve the understanding of the disease aetiology, a GWAS meta-analysis in cases with a diagnosis at ≤35 years of age was performed. MATERIALS AND METHODS: Genotypes from German, Dutch and Spanish GWAS studies of III/IV-C periodontitis diagnosed at age ≤35 years were imputed using TopMed. After quality control, a meta-analysis was conducted on 8,666,460 variants in 1306 cases and 7817 controls with METAL. Variants were prioritized using FUMA for gene-based tests, functional annotation and a transcriptome-wide association study integrating eQTL data. RESULTS: The study identified a novel genome-wide significant association in the FCER1G gene (p = 1.0 × 10-9 ), which was previously suggestively associated with III/IV-C periodontitis. Six additional genes showed suggestive association with p < 10-5 , including the known risk gene SIGLEC5. HMCN2 showed the second strongest association in this study (p = 6.1 × 10-8 ). CONCLUSIONS: This study expands the set of known genetic loci for severe periodontitis with an age of onset ≤35 years. The putative functions ascribed to the associated genes highlight the significance of oral barrier tissue stability, wound healing and tissue regeneration in the aetiology of these periodontitis forms and suggest the importance of tissue regeneration in maintaining oral health.

Effects of reducing free sugars on 24-hour glucose profiles and glycemic variability in subjects without diabetes.

Background: The Western diet, especially beverages and high processed food products, is high in sugars which are associated with the development of obesity and diabetes. The reduction of refined carbohydrates including free and added sugars improves glycemic control in individuals with diabetes, but the data regarding effects in subjects without diabetes are limited. Objective: This study aimed to evaluate the effects of reducing free sugar intake on 24-h glucose profiles and glycemic variability using continuous glucose monitoring (CGM). Methods: In the randomized controlled study, 21 normal weight and overweight/obese subjects (BMI 18-40 kg/m2) without diabetes were assigned to a 4-week reduced-sugar (RS) diet or control diet after a 2-week baseline phase. During the baseline phase, all participants were advised not to change their habitual diet. During the intervention phase, RS participants were asked to avoid added sugar and white flour products, whereas participants of the control group were requested to proceed their habitual diet. Anthropometric parameters and HbA1c were assessed before and at the end of the intervention phase. Interstitial glucose was measured using continuous glucose monitoring (CGM), and the food intake was documented by dietary records for 14 consecutive days during the baseline phase and for the first 14 consecutive days during the intervention phase. Mean 24-h glucose as well as intra- and inter-day indices of glucose variability, i.e., standard deviation (SD) around the sensor glucose level, coefficient of variation in percent (CV), mean amplitude of glucose excursions (MAGE), continuous overlapping net glycemic action (CONGA), and mean absolute glucose (MAG), were calculated for the baseline and intervention phases. Results: During the intervention, the RS group decreased the daily intake of sugar (i.e., -22.4 ± 20.2 g, -3.28 ± 3.61 EN %), total carbohydrates (-6.22 ± 6.92 EN %), and total energy intake (-216 ± 108 kcal) and increased the protein intake (+2.51 ± 1.56 EN %) compared to the baseline values, whereby this intervention-induced dietary changes differed from the control group. The RS group slightly reduced body weight (-1.58 ± 1.33 kg), BMI, total fat, and visceral fat content and increased muscle mass compared to the baseline phase, but these intervention-induced changes showed no differences in comparison with the control group. The RS diet affected neither the 24-h mean glucose levels nor intra- and inter-day indices of glucose variability, HbA1c, or diurnal glucose pattern in the within- and between-group comparisons. Conclusion: The dietary reduction of free sugars decreases body weight and body fat which may be associated with reduced total energy intake but does not affect the daily mean glucose and glycemic variability in individuals without diabetes. Clinical trial registration: German Clinical Trials Register (DRKS); identifier: DRKS00026699.

In vitro induction of Entamoeba gingivalis cyst-like structures from trophozoites in response to antibiotic treatment.

Background: Entamoeba gingivalis (E. gingivalis) is an anaerobic protozoan that is strongly associated with inflamed periodontal pockets. It is able to invade the mucosal epithelium of the human host, where it can feed on epithelial cells and elicit a severe innate immune response. Unlike other Entamoeba species, it is considered that E. gingivalis cannot form cysts, because it is a non-infectious protozoan. The lack of encystation capability would make it susceptible to periodontal treatment. However, it is not clear how the human host becomes infected with E. gingivalis trophozoites. We investigated the ability of E. gingivalis to encapsulate in response to an unfavorable environment in vitro. Methods: Different strains of E. gingivalis, isolated from inflamed periodontal pocket samples, were cultured for 8 days in the presence or absence of the antimicrobials amoxycillin and metronidazole. To reveal cyst formation, we investigated the morphology and ultrastructure of the amoeba by light, fluorescence, transmission and scanning electron microscopy. We also used the fluorescent dye calcofluor white M2R to demonstrate chitin present in the cyst wall. Results: We observed exocysts and an intra-cystic space separating the encapsulated trophozoite from the environment. Remarkably, cysts showed a smooth surface, polygonal edges and smaller size compared to free-living trophozoites. In addition, encapsulated trophozoites that detached from the cyst wall had a dense cytoplasma without phagocytic vesicles. The cyst walls consisted of chitin as in other Entamoba species. The encapsulated trophozoids were mononuclear after antibioticinduced encapsulation. Discussion: We conclude that E. gingivalis cyst formation has significant implications for dissemination and infection and may explain why established treatment approaches often fail to halt periodontal tissue destruction during periodontitis and peri-implantitis.

Anti-inflammatory IL-8 Regulation via an Advanced Drug Delivery System at the Oral Mucosa.

Oral inflammatory diseases are highly prevalent in the worldwide population. Topical treatment of inflammation is challenging due to dilution effects of saliva and crevicular fluid. Thus, there is a great medical need to develop smart anti-inflammatory drug delivery systems for mucosa treatment. We compared two promising anti-inflammatory dendritic poly(glycerol-caprolactone) sulfate (dPGS-PCL) polymers for their applicability to the oral mucosa. Using an ex vivo porcine tissue model, cell monolayers, and full-thickness 3D oral mucosal organoids, the polymers were evaluated for muco-adhesion, penetration, and anti-inflammatory properties. The biodegradable dPGS-PCL97 polymers adhered to and penetrated the masticatory mucosa within seconds. No effects on metabolic activity and cell proliferation were found. dPGS-PCL97 revealed a significant downregulation of pro-inflammatory cytokines with a clear preference for IL-8 in cell monolayers and mucosal organoids. Thus, dPGS-PCL97 exhibits excellent properties for topical anti-inflammatory therapy, suggesting new therapeutic avenues in the treatment of oral inflammatory diseases.

RSPO4 is a potential risk gene of stages III-IV, grade C periodontitis through effects on innate immune response and oral barrier integrity.

AIM: R-spondin 4 (RSPO4) is a suggestive risk gene of stage III-IV, grade C periodontitis and upregulated in gingiva of mice resistant to bacteria-induced alveolar bone loss. We aimed to replicate the association, identify and characterize the putative causal variant(s) and molecular effects, and understand the downstream effects of RSPO4 upregulation. MATERIALS AND METHODS: We performed a two-step association study for RSPO4 with imputed genotypes of a German-Dutch (896 stage III-IV, grade C periodontitis cases, 7104 controls) and Spanish sample (441 cases and 1141 controls). We analysed the allelic effects on transcription factor binding sites with reporter gene and antibody electrophoretic mobility shift assays. We used CRISPR/dCas9 activation and RNA sequencing to pinpoint RSPO4 as the target gene and to analyse downstream effects. RESULTS: RSPO4 was associated with periodontitis (rs6056178, pmeta  = 4.6 × 10-5 ). rs6056178 contains a GATA-binding motif. The rs6056178 T-allele abolished reporter activity (p = .004) and reduced GATA binding (-14.5%). CRISPRa of the associated region increased RSPO4 expression (25.8 ± 6.5-fold, p = .003). RSPO4 activation showed strongest induction of Gliomedin (439-fold) and Mucin 21 (178-fold) and of the gene set "response to interferon-alpha" (area under the curve [AUC] = 0.8, p < 5 × 10-6 ). The most repressed gene set was "extracellular matrix interactions" (AUC = 0.8, padj  = .00016). CONCLUSION: RSPO4 is a potential periodontitis risk gene and modifies host defence and barrier integrity.

Efficacy of professionally administered chemical agents as an adjunctive treatment to sub-marginal instrumentation during the therapy of peri-implant mucositis.

AIM: To evaluate the efficacy of professionally administered chemical agents as an adjunctive treatment to sub-marginal instrumentation (SMI) in the therapy of peri-implant mucositis. MATERIALS AND METHODS: The primary outcome criteria were reduction in bleeding on probing (BOP), whereas resolution of disease, elimination of suppuration, including suppuration on probing, reduction of peri-implant probing pocket depth, reduction of plaque, and patient-reported outcome measures were considered as secondary outcome parameters. A literature search was performed on three electronic databases (01/1980 to 05/2022) focused on clinical studies with at least 3 months of follow-up, and meta-analyses were performed when appropriate. RESULTS: From a total of 139 publications, 40 articles were identified for full-text reading, and 5 randomized controlled clinical trials (RCTs) on antimicrobial photodynamic therapy (aPDT), 1 RCT on chlorhexidine (CHX), and 1 RCT on sodium hypochlorite (NaOCl) were included. Three studies had a low risk of bias and four had a mid-level (some concerns) risk of bias. The application of aPDT, 0.95% NaOCl, or 0.12% CHX as an adjunctive treatment to SMI showed no difference in changes in BOP and PD compared with SMI alone (p > .05). CONCLUSIONS: Within the limitations of this review and based on a low level of evidence from seven RCTs, it is concluded that the professional adjunctive topical application of aPDT, 0.95% NaOCl, and 0.12% CHX may not be effective to improve changes for BOP and PD when compared with SMI alone.

Case-only design identifies interactions of genetic risk variants at SIGLEC5 and PLG with the lncRNA CTD-2353F22.1 implying the importance of periodontal wound healing for disease aetiology.

AIM: The basis of phenotypic variation of periodontitis is genetic variability. Disease relevant effects of individual risk alleles are considered to result from genetic interactions. We investigated gene × gene (G×G) interactions of suggestive periodontitis susceptibility alleles. MATERIALS AND METHODS: We used the case-only design and investigated single-nucleotide polymorphism (SNPs) that showed associations in our recent genome-wide association study (GWAS) and GWAS meta-analysis with p < 5 × 10-6 . CRISPR-dCas9 gene activation followed by RNA-sequencing and gene-set enrichment analyses elucidated differentially expressed genes and gene networks. With the databases of SNPInspector and Transfac professional, luciferase reporter gene assays and antibody electrophoretic mobility shift experiments, we analysed allele-specific effects on transcription factor binding. RESULTS: SNPs at the genes sialic acid binding Ig-like lectin 5 (SIGLEC5) and plasminogen (PLG) showed G×G interactions with rs1122900 at the long non-coding RNA (lncRNA) CTD-2353F22. Associated chromatin cis-activated CTD-2353F22.1 6.5-fold (p = .003), indicating CTD-2353F22.1 as target gene of this interaction. CTD-2353F22.1 regulated GADD45A (padj < 4.9 × 10-11 , log2 fold change (FC) = -0.55), THBS1, SERPINE1 and Tissue Factor F3 (padj < 5 × 10-7 , log2 FC ≥ -0.35) and the gene set "angiogenesis" (area under the curve = 0.71, padj  = 8.2 × 10-5 ). rs1122900 effect C-allele decreased reporter gene activity (5.5-fold, p = .0003) and PRDM14 binding (76%). CONCLUSIONS: CTD-2353F22.1 mediates interaction of SIGLEC5 and PLG, together with genes that function in periodontal wound healing.

Novel Adhesive Nanocarriers Based on Mussel-Inspired Polyglycerols for the Application onto Mucosal Tissues.

A synthetic route for adhesive core-multishell (CMS) nanocarriers for application to the oral mucosa was established using mussel-inspired catechol moieties. The three CMS nanocarriers with 8%, 13%, and 20% catechol functionalization were evaluated for loading capacity using Nile red, showing an overall loading of 1 wt%. The ability of Nile red loaded and functionalized nanocarriers to bind to a moist mucosal surface was tested in two complementary adhesion assays under static and dynamic conditions using monolayers of differentiated gingival keratinocytes. Adhesion properties of functionalized nanocarriers were compared to the adhesion of the non-functionalized nanocarrier. In both assays, the CMS nanocarrier functionalized with 8% catechol exhibited the strongest adhesion compared to its catechol-free counterpart and the CMS nanocarriers functionalized with 13% and 20% catechol.

Comparison of five-year survival rates among patients with oral squamous cell carcinoma with and without association with syphilis: a retrospective case-control study.

BACKGROUND: Syphilis is an infectious disease that is at least discussed to be premalignant. This potential, combined with its general pathological impact, raises the question if syphilis increases mortality in oral cancer patients. The aim of the study was to assess if the five-year survival rates among patients suffering from oral squamous cell carcinoma (OSCC) with (cohort I) and without association with syphilis (cohort II) differ. METHODS: Retrospective clinical data of patients diagnosed with OSCC (International Classification of Diseases [ICD]-10 codes C01-06) within the past 20 years from the access date September 25, 2021 were retrieved from the TriNetX network (TriNetX, Cambridge, Massachusetts, USA) to gain initial cohort 0. Subjects also diagnosed with syphilis (ICD-10 codes A51-53) were assigned to cohort I. Cohort II was comprised of the remaining individuals of cohort 0 by creating a group with the same number of patients as cohort I, and by matching for age and gender. Subsequently, Kaplan-Meier analysis and Cox proportional hazards regression were performed, and risk, odds and hazard ratios were calculated. RESULTS: Of a total of 73,736 patients in cohort 0, 199 individuals were each assigned to cohort I and II. During the five-year period after tumor diagnosis, 39 and 30 patients in cohort I and II died. The five-year survival probabilities did not significantly differ between the cohorts (I vs. II = 74.19% vs. 75.01%; p = 0.52; Log-Rank test), nor the risk of dying (I vs. II = 19.6% vs. 15.08%; risk difference = 4.52%; p = 0.23). The calculated risk, odds and hazard ratios were 1.3 (95% confidence interval [CI] = 0.84; 2.00), 1.37 (95% CI = 0.81; 2.31) and 1.17 (95% CI = 0.73; 1.88), respectively. CONCLUSIONS: The obtained results indicate that the survival rate of individuals with OSCC might not be negatively influenced if syphilis is present/associated. However, the results need to be interpreted cautiously due to limitations related to the retrospective approach, especially as data on the tumor staging were not accessible. TRIAL REGISTRATION: Due to the retrospective nature of the study, no registration was necessary.

Efficacy of tooth splinting and occlusal adjustment in patients with periodontitis exhibiting masticatory dysfunction: A systematic review.

OBJECTIVE: To evaluate the efficacy of tooth splinting (TS) and occlusal adjustment (OA) compared to no TS or OA in patients with periodontitis exhibiting masticatory dysfunction. MATERIAL: The primary outcome criterion was tooth loss (TL), and the secondary outcome parameters were change in probing pocket depth (PPD), change in clinical attachment level (CAL), tooth mobility (TM), and patient-reported outcome measures (PROMs). Literature search was performed on three electronic databases (from 01/1965 to 04/2021) and focused on clinical studies with at least 12 months follow-up. RESULTS: From a total of 1515 publications, 51 articles were identified for full-text reading, of which 2 retrospective case series on TS with low risk of bias and 1 randomized and 2 prospective studies on OA with unclear risk of bias were included. For TS, synthesis of data showed that in 72 patients, 26 out of 311 teeth (weighted mean incidence of TL 8.4%) and 156 out of 1541 teeth with no TS (weighted mean incidence of TL 10.1%) were lost over 2 years following non-surgical periodontal therapy. The randomized controlled clinical trial (RCT) indicated CAL gain for teeth with OA compared to no OA. For the effect of OA on TL, PPD, and TM, heterogeneous data were retrieved from the included studies. CONCLUSIONS: Within the limitations of this review and based on a low level of evidence, it is concluded that TS does not improve survival of mobile teeth in patients with advanced periodontitis. OA on teeth with mobility and/or premature contacts may lead to improved CAL, while the effect of OA on the remaining periodontal parameters remains unclear.

Epigenetic adaptations of the masticatory mucosa to periodontal inflammation.

BACKGROUND: In mucosal barrier interfaces, flexible responses of gene expression to long-term environmental changes allow adaptation and fine-tuning for the balance of host defense and uncontrolled not-resolving inflammation. Epigenetic modifications of the chromatin confer plasticity to the genetic information and give insight into how tissues use the genetic information to adapt to environmental factors. The oral mucosa is particularly exposed to environmental stressors such as a variable microbiota. Likewise, persistent oral inflammation is the most important intrinsic risk factor for the oral inflammatory disease periodontitis and has strong potential to alter DNA-methylation patterns. The aim of the current study was to identify epigenetic changes of the oral masticatory mucosa in response to long-term inflammation that resulted in periodontitis. METHODS AND RESULTS: Genome-wide CpG methylation of both inflamed and clinically uninflamed solid gingival tissue biopsies of 60 periodontitis cases was analyzed using the Infinium MethylationEPIC BeadChip. We validated and performed cell-type deconvolution for infiltrated immune cells using the EpiDish algorithm. Effect sizes of DMPs in gingival epithelial and fibroblast cells were estimated and adjusted for confounding factors using our recently developed "intercept-method". In the current EWAS, we identified various genes that showed significantly different methylation between periodontitis-inflamed and uninflamed oral mucosa in periodontitis patients. The strongest differences were observed for genes with roles in wound healing (ROBO2, PTP4A3), cell adhesion (LPXN) and innate immune response (CCL26, DNAJC1, BPI). Enrichment analyses implied a role of epigenetic changes for vesicle trafficking gene sets. CONCLUSIONS: Our results imply specific adaptations of the oral mucosa to a persistent inflammatory environment that involve wound repair, barrier integrity, and innate immune defense.

Comparison of three full-mouth concepts for the non-surgical treatment of stage III and IV periodontitis: A randomized controlled trial.

AIM: To evaluate the clinical efficacy of full-mouth scaling (FMS), full-mouth disinfection (FMD), and FMD with adjuvant erythritol air-polishing (FMDAP) compared to quadrant-wise debridement (Q-SRP) in patients with periodontitis stage III/IV. METHODS: In this four-arm parallel, prospective, randomized, controlled multi-centre study, changes of pocket probing depths (PPDs), clinical attachment level (CAL), bleeding on probing (BOP), and proportion of closed pockets (PPD ≤4 mm without BOP) were evaluated at baseline and after 3 and 6 months. RESULTS: From 190 randomly participating patients, 172 were included in the final analysis. All groups showed significant (p < .05) improvements in all clinical parameters over 3 and 6 months. During the study period, FMDAP showed significantly higher reductions of mean PPD in teeth with moderate (PPD 4-6 mm) and deep (PPD > 6 mm) pockets and significantly increased proportions of pocket closure than Q-SRP. Patients treated with FMD had significantly greater PPD reduction in deep pockets and a higher percentage of pocket closure after 3 months but not after 6 months compared to Q-SRP. CAL and BOP changes did not significantly differ among all groups. Efficiency of treatment (time effort to gain one closed pocket) was significantly higher for FMDAP, FMD, and FMS compared to Q-SRP (6.3, 8.5, 9.5 vs. 17.8 min per closed pocket; p < .05). CONCLUSIONS: All treatment modalities were effective, without significant differences between full-mouth approaches. FMDAP showed improved clinical outcomes over Q-SRP for moderate and deep pockets after 6 months. Full-mouth protocols were more time-efficient than conventional Q-SRP. CLINICAL SIGNIFICANCE: The trial was registered in a clinical trial database (ClinicalTrials.gov: NCT03509233).

Sex-specific genetic factors affect the risk of early-onset periodontitis in Europeans.

AIMS: Various studies have reported that young European women are more likely to develop early-onset periodontitis compared to men. A potential explanation for the observed variations in sex and age of disease onset is the natural genetic variation within the autosomal genomes. We hypothesized that genotype-by-sex (G × S) interactions contribute to the increased prevalence and severity. MATERIALS AND METHODS: Using the case-only design, we tested for differences in genetic effects between men and women in 896 North-West European early-onset cases, using imputed genotypes from the OmniExpress genotyping array. Population-representative 6823 controls were used to verify that the interacting variables G and S were uncorrelated in the general population. RESULTS: In total, 20 loci indicated G × S associations (P < 0.0005), 3 of which were previously suggested as risk genes for periodontitis (ABLIM2, CDH13, and NELL1). We also found independent G × S interactions of the related gene paralogs MACROD1/FLRT1 (chr11) and MACROD2/FLRT3 (chr20). G × S-associated SNPs at CPEB4, CDH13, MACROD1, and MECOM were genome-wide-associated with heel bone mineral density (CPEB4, MECOM), waist-to-hip ratio (CPEB4, MACROD1), and blood pressure (CPEB4, CDH13). CONCLUSIONS: Our results indicate that natural genetic variation affects the different heritability of periodontitis among sexes and suggest genes that contribute to inter-sex phenotypic variation in early-onset periodontitis.

Reduction of dual-species biofilm after sonic- or ultrasonic-activated irrigation protocols: A laboratory study.

AIM: To evaluate the antibacterial effect of sonic- and ultrasonic-activated irrigation on bacterial reduction of a dual-species biofilm in root canals compared to nonactivated irrigation in a laboratory study. METHODOLOGY: Two hundred and forty extracted human single-rooted maxillary anterior teeth were divided into two main groups (G, n = 120) according to the initial preparation size of the root canal (G1: size 25, 0.06 taper, G2: size 40, 0.06 taper). Root canals were inoculated with Enterococcus faecalis and Streptococcus oralis. After 5 days, G1 received combined instrumentation (up to size 40, 0.06 taper) and irrigation/activation, whereas G2 received solely irrigation/activation protocols. In both groups, irrigation was performed with sodium hypochlorite (NaOCl 1%) or physiological saline (NaCl 0.9%), using nonactivated syringe irrigation, sonic activation (2 x 30 s) or ultrasonic activation (2 x 30 s). Logarithmic reduction factors (LRFs) of colony-forming units were analysed separately for dentine-adherent and planktonic bacteria immediately after irrigation/activation protocols (time-point 1) or after 5 days of further incubation (time-point 2) by analysis of variance (anova) and post hoc tests (Tukey's HSD, t-test). The significance level was set at 0.05. RESULTS: In G1 subgroups (combined instrumentation with irrigation/activation), LRFs were significantly affected by the applied irrigation solution (p < .0001), but not by the activation method (p > .05; anova). In G2 subgroups (solely irrigation/activation), both, irrigant solution and activation, significantly affected LRFs (p < .0001, anova). Sonic activation resulted in significantly higher LRFs than ultrasonic activation (p < .0001) which had significantly greater reductions than nonactivated irrigation (p < .05; Tukey's HSD). At T2, strong bacterial regrowth was observed in all groups; however, a significant bacterial reduction was detected for factors instrumentation, irrigant solution and activation (p < .0001; anova). Similar LRFs were found for dentine-adherent and planktonic bacterial cells in all groups (r = 0.91 at T1, r = 0.8 at T2). CONCLUSIONS: In this laboratory study on extracted maxillary anterior teeth high-frequency sonic activation resulted in a greater bacterial reduction compared to ultrasonic activation in groups receiving solely irrigation/activation protocols; however, irrigation using NaOCl and ultrasonic activation also contributed significantly to bacterial reduction compared to the control groups.

hsa-miR-374b-5p regulates expression of the gene U2AF homology motif (UHM) kinase 1.

OBJECTIVE: We aimed to identify a microRNA (miRNA) that is significantly upregulated in blood and in cells of the oral mucosa upon exposure to the periodontitis main risk factors oral inflammation and tobacco smoke, to subsequently identify its target gene and to describe the molecular mechanism of gene regulation. BACKGROUND: miRNAs are associated with many disorders. Array-based miRNA expression studies indicated a number of differentially expressed miRNAs in the pathology of oral diseases. However, these miRNAs mostly lacked replication, and their target genes have remained unknown. METHODS: 863 miRNAs were analyzed in blood from 18 PD cases and 70 controls (Geniom Biochip). Selected miRNAs were analyzed for upregulation in the inflamed oral mucosa of PD patients using published miRNA expression profiling studies from gingival cells. hsa-miR-374b-5p mimic was overexpressed in primary gingival fibroblasts (pGFs) from 3 donors, and genome-wide mRNA expression was quantified (Clarion Array). Gene-specific regulation was validated by qRT-PCR and Luciferase activity in HeLa cells. RESULTS: hsa-miR-374b-5p showed >twofold change (FC) in 3 independent studies performed in blood, gingival tissues, and cells. After hsa-miR-374b-5p overexpression, genome-wide expression analysis showed UHMK1 as top 1 downregulated gene in pGFs (p = 2.5 × 10-04 , fold change = -1.8). Reporter genes demonstrated that hsa-miR-374b-5p downregulates mRNA levels (p = .02; FC = -1.5), leading to reduction in protein activity (p = .013, FC = -1.3). CONCLUSIONS: hsa-miR-374b-5p is upregulated in blood and ginvial cells exposed to oral inflammation and tobacco smoke and regulates UHMK1, which has a role in osteoclast differentiation.