Evaluating clinical utility of subgingival and salivary endotoxin activity levels as periodontal biomarkers.

Objectives: The use of periodontal biomarkers for identification and monitoring of unique patient populations could foster better stratification of at-risk groups, increase access to treatment for those most in need, facilitate preventive measures and improve personalised care plans. The aim of this study was to examine the diagnostic and prognostic utility of oral lipopolysaccharides as bacterially-derived periodontal biomarkers. Methods: Periodontal parameters were recorded, and saliva and subgingival plaque samples were collected at the beginning of the study from periodontally healthy volunteers and periodontitis patients, and three months after completion of conventional periodontal treatment in the periodontitis group. Endotoxin activity in the samples was measured using the recombinant factor C assay. Associations between clinical periodontal parameters and subgingival and salivary endotoxin activities were analysed using a multivariate regression model, while the ROC curve was applied to estimate the sensitivity, specificity and c-statistics for salivary and subgingival endotoxin activities as diagnostic biomarkers for periodontitis. Results: Significant correlations were found between subgingival endotoxin activities, probing pocket depth and periodontal diagnosis, which were independent from patients' age, gender and smoking status. In addition, subgingival endotoxin levels had high specificity and sensitivity in detecting periodontal health and disease (0.91 and 0.85 respectively). Salivary endotoxin activity was positively associated with periodontal diagnosis, mean probing pocket depth, percentages of sites over 4 mm and full mouth bleeding score. However, it was inferior in discriminating patients with stable periodontium from those with periodontitis (sensitivity = 0.69, specificity = 0.61) compared to subgingival endotoxin activity. Conclusions: Subgingival endotoxin activity has good diagnostic and prognostic values as a site-specific periodontal biomarker and is not influenced by the patient's age, gender or smoking status. In contrast, salivary endotoxin activity, as a patient-level biomarker, is dependent on patient's age, has poorer diagnostic and prognostic capability, but shows good correlations with disease susceptibility and both its extent and severity.

Emergency dental care triage during the COVID-19 pandemic.

Introduction Due to the COVID-19 pandemic, from 23 March 2020, routine dental treatment was stopped by the Chief Dental Officer, with the emphasis towards urgent dental care only.Aim To evaluate the activities of the emergency service at a secondary care Urgent Dental Care (UDC) hub during the COVID-19 pandemic.Materials and methods The total number of patients seen from 30 March to 20 June 2020 was recorded. The effectiveness of telephone triage and the appropriateness of patients invited for a clinical assessment were evaluated over a two-week period.Results The number of calls into the UDC hub were highest during the first few weeks, with up to 249 per day. The most commonly provided emergency treatments included extractions and pulp extirpations.Discussion As other UDC hubs opened, the number of calls reduced, with patients being directed to a UDC nearer to where they lived.Conclusions The dental profession had to make some significant changes in the way they worked due to the risk of COVID-19 transmission and due to the effects of the lockdown. This review highlights the effectiveness of telephone triage as well as its drawbacks.

Effect of Treatment of Periodontitis on Incretin Axis in Obese and Nonobese Individuals: A Cohort Study.

CONTEXT: Periodontitis confers an increased risk of developing type 2 diabetes and, in patients with obesity, it might interfere with the incretin axis. The effect of periodontal treatment on glucoregulatory hormones remains unknown. OBJECTIVE: To evaluate the effect of periodontal treatment on incretin axis in obese and lean nondiabetic individuals. SETTING: King's College Dental Hospital and Institute, London, UK. PARTICIPANTS AND METHODS: The metabolic profile of obese and normal-body-mass-index individuals affected by periodontitis was studied at baseline, 2, and 6 months after intensive periodontal treatment, by measuring plasma insulin, glucagon, glucagon-like peptide-1(GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) and markers of systemic inflammation and oxidative stress. MAIN OUTCOME MEASURE(S): Circulating levels of incretins and inflammatory markers. RESULTS: At baseline, periodontal parameters were worse for obese than nonobese; this was accompanied by higher levels of circulating high-sensitivity C-reactive protein (hs-CRP), insulin, and GLP-1. The response to periodontal treatment was less favorable in the obese group, without significant variations of hs-CRP or malondialdehyde. Glucoregulatory hormones changed differently after treatment: while insulin and glucagon did not vary at 2 and 6 months, GLP-1 and GIP significantly increased at 6 months in both groups. In particular, GLP-1 increased more rapidly in obese participants, while the increase of GIP followed similar trends across visits in both groups. CONCLUSIONS: Nonsurgical treatment of periodontitis is associated with increased GLP-1 and GIP levels in nonobese and obese patients; changes in GLP-1 were more rapid in obese participants. This might have positive implications for the metabolic risk of these individuals.

Obesity as predictive factor of periodontal therapy clinical outcomes: A cohort study.

AIM: The study aim was to investigate the predictive role of obesity on clinical response following non-surgical periodontal therapy in individuals with severe periodontitis. METHODS: A total of 57 BMI obese and 58 BMI normal non-smoker adults with periodontitis (defined as probing pocket depths (PPD) of ≥5 mm and alveolar bone loss of >30% with >50% of the teeth affected) received non-surgical periodontal therapy. Periodontal status was based upon PPD, clinical attachment level (CAL) and full-mouth bleeding score (FMBS). Mean PPD, percentage sites PPD >4 mm, percentage sites PPD >5 mm and FMBS at 2 and 6 months were outcome variables. Propensity score analysis was used to assess the effect of obesity on outcome variables after adjusting for confounders. RESULTS: Statistically significant higher clinical measures (mean PPD, mean percentage of sites with PPD >4 mm, mean percentage of sites with PPD >5 mm and FMBS) were observed in the obese group than the normal group at baseline, 2 and 6 months after therapy (p < .01). At 2 and 6 months, obesity was associated with worse mean PPD (p < .05), percentage sites with PPD >4 mm (p < .05), percentage sites with PPD > 5mm (p < .05) and FMBS (p < .01), independent of age, gender, ethnicity or plaque levels. CONCLUSIONS: Obesity compared to normal BMI status was an independent predictor of poorer response following non-surgical periodontal therapy.

Comparative analysis of total salivary lipopolysaccharide chemical and biological properties with periodontal status.

OBJECTIVE: Clinical manifestations of Gram-negative bacteria mediated diseases can be influenced by how the host senses their major microbe-associated molecular pattern, the cell wall lipopolysaccharide (LPS). Keystone periodontal pathogens can produce a heterogeneous population of LPS molecules, with strikingly different host-microbiome interactions and immune outcomes. DESIGN: Structure-function correlations of salivary LPS extracts in patients with periodontitis before and after periodontal treatment and healthy volunteers were analysed by comparing its lipid A and carbohydrate chain chemical structure and evaluating its endotoxin activity and inflammatory potential. RESULTS: Salivary LPS extracts from periodontitis patients were characterised by high m/z lipid A mass-spectrometry peaks, corresponding to over-acylated and phosphorylated lipid A ions and by a combination of rough and smooth LPS carbohydrate moieties. In contrast, gingival health was defined by the predominance of low m/z lipid A peaks, consistent with under-acylated and hypo-phosphorylated lipid A molecular signatures, with long and intermediate carbohydrate chains as determined by silver staining. Total, diseased salivary LPS extracts were stronger inducers of the recombinant factor C assay and triggered significantly higher levels of TNF-α, IL-8 and IP-10 production in THP-1 cells, compared to almost immunosilent healthy samples. Interestingly, salivary LPS architecture, endotoxin activity, and inflammatory potential were well conserved after periodontal therapy and showed similarities to diseased samples. CONCLUSIONS: This study sheds new light on molecular pathogenic mechanisms of oral dysbiotic communities and indicates that the regulation of LPS chemical structure is an important mechanism that drives oral bacteria-host immune system interactions into either a symbiotic or pathogenic relationship.

Subgingival lipid A profile and endotoxin activity in periodontal health and disease.

OBJECTIVES: Regulation of lipopolysaccharide (LPS) chemical composition, particularly its lipid A domain, is an important, naturally occurring mechanism that drives bacteria-host immune system interactions into either a symbiotic or pathogenic relationship. Members of the subgingival oral microbiota can critically modulate host immuno-inflammatory responses by synthesizing different LPS isoforms. The objectives of this study were to analyze subgingival lipid A profiles and endotoxin activities in periodontal health and disease and to evaluate the use of the recombinant factor C assay as a new, lipid A-based biosensor for personalized, point-of-care periodontal therapy. MATERIALS AND METHODS: Subgingival plaque samples were collected from healthy individuals and chronic periodontitis patients before and after periodontal therapy. Chemical composition of subgingival lipid A moieties was determined by ESI-Mass Spectrometry. Endotoxin activity of subgingival LPS extracts was assessed using the recombinant factor C assay, and their inflammatory potential was examined in THP-1-derived macrophages by measuring TNF-α and IL-8 production. RESULTS: Characteristic lipid A molecular signatures, corresponding to over-acylated, bi-phosphorylated lipid A isoforms, were observed in diseased samples. Healthy and post-treatment samples were characterized by lower m/z peaks, related to under-acylated, hypo-phosphorylated lipid A structures. Endotoxin activity levels and inflammatory potentials of subgingival LPS extracts from periodontitis patients were significantly higher compared to healthy and post-treatment samples. CONCLUSIONS: This is the first study to consider structure-function-clinical implications of different lipid A isoforms present in the subgingival niche and sheds new light on molecular pathogenic mechanisms of subgingival biofilm communities. CLINICAL RELEVANCE: Subgingival endotoxin activity (determined by lipid A chemical composition) could be a reliable, bacterially derived biomarker and a risk assessment tool for personalized periodontal care.

Localised periodontitis associated with an ectopic orthodontic separator.

A case of localised periodontitis associated with a subgingival orthodontic separator is presented. The presence of this object was related to quite severe periodontal breakdown around an upper right first premolar tooth in an otherwise unsusceptible individual.

Replacement of missing teeth with fixed prostheses.

This article explores the various treatment options available to replace missing teeth with a fixed prosthesis. It discusses the requirements for each treatment modality and its associated advantages and disadvantages.

An in vitro study to investigate the load at fracture of Procera AllCeram crowns with various thickness of occlusal veneer porcelain.

PURPOSE: The aim of this study was to investigate the effect of occlusal veneer porcelain thickness on the load at fracture of Procera AllCeram crowns. MATERIALS AND METHODS: Fifty resin dies were manufactured to incorporate the features of an all-ceramic crown preparation on a premolar tooth. Fifty corresponding crowns were constructed and divided into five groups. Groups 1, 2, 3, and 4 were crowns with 0.6-mm-thick Procera cores and 0.4-mm-thick axial veneer porcelain and occlusal veneer porcelain thicknesses of 0.0 mm, 0.4 mm, 0.9 mm, and 1.4 mm, respectively. Group 5 specimens consisted of 0.6-mm-thick In-Ceram cores with 0.4 mm of axial porcelain and 0.4 mm of occlusal porcelain. The crowns were cemented onto their respective dies with a resin luting agent. Specimens were stored in distilled water at 37 degrees C for 24 hours prior to placing them in a universal testing machine and applying a controlled compressive load at a cross-head speed of 0.1 mm/min until fracture occurred. RESULTS: The mean loads at fracture were 419 N (group 1), 702 N (group 2), 1,142 N (group 3), 1,297 N (group 4), and 732 N (group 5). Statistical analysis revealed significant differences (P < .05) in the load at fracture between the groups, except for between groups 2 and 5. CONCLUSION: Increasing the thickness of the occlusal veneer porcelain increased the load at fracture for Procera AllCeram crowns. There was no significant difference in load at fracture between the Procera and In-Ceram crowns.