Post-treatment evaluation of oral health-related quality of life in head and neck cancer patients after dental implant rehabilitation.

Objectives To assess oral health-related quality of life (OHRQoL) following oral rehabilitation using dental implants in patients treated for head and neck cancer (HNC).Materials and methods Service evaluation: patients who had received dental implants during their oral rehabilitation were invited to take part (n = 81). In total, 37 patients completed questionnaires and underwent a structured interview regarding OHRQoL after rehabilitation. Analysis was by descriptive statistics for questionnaire and thematic analysis of interview.Results Rehabilitation types were 17 fixed implant prostheses, 12 removable implant prostheses and 8 combination. Functional problems relating to HNC treatment had a significant effect on OHRQoL and persisted after rehabilitation. Removable implant prostheses had more problems associated than fixed. At interview, patients described: functional and emotional benefits of oral rehabilitation involving implants; ease of keeping implants clean; variations in ability of primary care dentists to maintain rehabilitation; thankfulness to have received treatment; long duration of rehabilitation; and problems encountered while undergoing rehabilitation.Conclusions HNC treatment results in functional and emotional difficulties, which has a significant impact on OHRQoL. Use of dental implants in fixed or removable oral rehabilitation can result in good OHRQoL as assessed by patients at treatment completion, although some functional difficulties often remain.

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.

Correlations Between Final-Year Dental Students' Performance on Knowledge-Based and Clinical Examinations.

Dental students are assessed using a range of methods in their final-year examinations. The aim of this study was to explore the correlations and predictive value of final-year dental students' performance on knowledge-based and clinical assessments. Examination data related to applied dental knowledge (ADK), exit case presentation (CP), and integrated structured clinical examination (ISCE) assessments for five consecutive cohorts of final-year students at one U.K. dental school from 2011-12 to 2015-16 were collated. The relationships between the scores produced by each assessment were investigated to explore the relative contributions of each to the understanding of students' abilities across the domains. The study utilized data from all 304 students: 147 (48.4%) females and 157 (51.6%) males. Significant positive correlations were found between ISCE and ADK performance (r(391)=0.42, p<0.001) as well as between ISCE and CP (r(391)=0.44, p<0.001). In addition, both ADK performance and CP performance were significant predictors (at p<0.001) of ISCE performance. This study provides important information about the relationship between these students' performance across knowledge (ADK) and clinical (ISCE and CP) domains and highlights their predictive value. Further research is required to establish if these findings can be generalized and to explore the correlations between performance of dental students before and after graduation.