Détermination des types de symétrie de quelques vibrations du naphtalène

Etude des spectres de fluorescence à 4 °K de solutions dans le pentane n des molécules suivantes : naphtalène, acénaphtène, 2,6-diméthylnaphtalène, α et β-méthylnaphtalène. La structure vibrationnelle de ces spectres et l'usage de la théorie des groupes permet de répartir 19 vibrations du naphtalène entre les trois types de symétrie Ag, B1g B2u. Les résultats sont, en grande partie, conformes à ceux de Mc Clellan et Pimentel

Parodontite et polyarthrite rhumatoïde

TOULOUSE3-BU Santé-Centrale (315552105) / SudocSudocFranceF

Survival of directly placed ormocer-based restorative materials: A systematic review and meta-analysis of clinical trials

International audienceObjectivesIn-vitro experiments on ormocers (ORganically MOdified CERamics) have provided controversial results. Consequently, the objectives of this meta-analysis were to (1) compare clinical performances of first generation ormocers versus conventional composite restorations, (2) explore the influence of various clinical factors and the impact of the quality of studies on published results.MethodsThe following databases were explored until 2017/01/08: Ovid MEDLINE In-Process, Pubmed, CENTRAL, HTA, DARE, LILACS and Google Scholar.Studies of more than two years with quantitative comparisons between ormocers and control groups were selected. Outcome was the failure of a restoration (need to repair, remove or replace). Multivariate random-effects Poisson’s regression was used to obtain a summary estimate.Results75% of the 8 included trials concerned Class I/II restorations. Although non-significant, the global failures were higher for ormocers (0.22 [−0.16; 0.61]). For Class I/II restorations, a significantly higher sensitivity was observed for ormocer-based materials compared to other composites (0.75 [0.01; 1.50]). An increase of the number of restorations per patient was associated with higher marginal adaptation failures for ormocers in Class I/II obturations (0.59 [0.11; 1.08]).SignificanceThis study did not identify clear advantages of using the first generation of ormocer-based fillings rather than conventional composites. Given the recent development of new, dimethacrylate-diluent-free ormocer matrices, potentially more stable and resistant, new randomized clinical trials should be developed comparing this new family of pure ormocers with current composites

Recent advances in cone-beam CT in oral medicine

Background: The cone-beam computed tomography (CBCT) technology has continuously evolved since its appearance in oral medicine in the early 2000s. Objective: To present recent advances in CBCT in oral medicine: i) selection of recent and consensual evidence-based sources, ii) structured summary of the information based on an iterative framework and iii) compliance with ethical, public health and patient-centered concerns. Main Findings: We will focus on technological advances, such as sensors and reconstruction algorithms used to improve the constant quality of the image and dosimetry. CBCT examination is now performed in almost all disciplines of oral medicine: currently, the main clinical disciplines that use CBCT acquisitions are endodontics and oral surgery, with clearly defined indications. Periodontology and ear, nose and throat medicine are more recent fields of application. For a given application and indication, the smallest possible field of view must be used. One of the major challenges in contemporary healthcare is ensuring that technological developments do not take precedence over admitted standards of care. The entire volume should be reviewed in full, with a systematic approach. All findings are noted in the patient’s record and explained to the patient, including incidental findings. This presupposes the person reviewing the images is sufficiently trained to interpret such images, inform the patient and organize the clinical pathway, with referrals to other medical or oral medicine specialties as needed. Conclusion: A close collaboration between dentists, medical physicists, radiologists, radiographers and engineers is critical for all aspects of CBCT technology

Recent advances in cone-beam CT in oral medicine

Background: The cone-beam computed tomography (CBCT) technology has continuously evolved since its appearance in oral medicine in the early 2000s. Objective: To present recent advances in CBCT in oral medicine: i) selection of recent and consensual evidence-based sources, ii) structured summary of the information based on an iterative framework and iii) compliance with ethical, public health and patient-centered concerns. Main Findings: We will focus on technological advances, such as sensors and reconstruction algorithms used to improve the constant quality of the image and dosimetry. CBCT examination is now performed in almost all disciplines of oral medicine: currently, the main clinical disciplines that use CBCT acquisitions are endodontics and oral surgery, with clearly defined indications. Periodontology and ear, nose and throat medicine are more recent fields of application. For a given application and indication, the smallest possible field of view must be used. One of the major challenges in contemporary healthcare is ensuring that technological developments do not take precedence over admitted standards of care. The entire volume should be reviewed in full, with a systematic approach. All findings are noted in the patient’s record and explained to the patient, including incidental findings. This presupposes the person reviewing the images is sufficiently trained to interpret such images, inform the patient and organize the clinical pathway, with referrals to other medical or oral medicine specialties as needed. Conclusion: A close collaboration between dentists, medical physicists, radiologists, radiographers and engineers is critical for all aspects of CBCT technology

Parodontite maternelle et causes d’accouchement prématuré

L’objectif de l’étude était d’analyser l’association entre la parodontite maternelle et l’accouchement prématuré, selon les causes de prématurité. L’étude EPIPAP a été menée dans six maternités françaises sur 1108 femmes (cas) ayant donné naissance à un enfant prématuré (<37 semaines d’aménorrhée SA) et 1094 femmes (témoins) ayant donné naissance à un enfant à terme (≥37 SA). L’état parodontal a été défini en parodontite absente, localisée, généralisée. Les cas ont été classés selon 4 causes de prématurité (induite pour prééclampsie, induite pour retard de croissance intra-utérin, spontanée/induite pour rupture prématurée des membranes, autres causes). La parodontite généralisée était associée à une augmentation du risque d’accouchement prématuré induit pour cause de prééclampsie (ORa=2,46; IC 95 % [1,58-3,83]). Aucune association n’a été mise en évidence avec les autres causes de prématurité

Systemic Periodontal Risk Score Using an Innovative Machine Learning Strategy: An Observational Study

Editors: Aristotelis Chatziioannou and Yudong ZhangInternational audienceEarly diagnosis is crucial for individuals who are susceptible to tooth-supporting tissue diseases (e.g., periodontitis) that may lead to tooth loss, so as to prevent systemic implications and maintain quality of life. The aim of this study was to propose a personalized explainable machine learning algorithm, solely based on non-invasive predictors that can easily be collected in a clinic, to identify subjects at risk of developing periodontal diseases. To this end, the individual data and periodontal health of 532 subjects was assessed. A machine learning pipeline combining a feature selection step, multilayer perceptron, and SHapley Additive exPlanations (SHAP) explainability, was used to build the algorithm. The prediction scores for healthy periodontium and periodontitis gave final F1-scores of 0.74 and 0.68, respectively, while gingival inflammation was harder to predict (F1-score of 0.32). Age, body mass index, smoking habits, systemic pathologies, diet, alcohol, educational level, and hormonal status were found to be the most contributive variables for periodontal health prediction. The algorithm clearly shows different risk profiles before and after 35 years of age and suggests transition ages in the predisposition to developing gingival inflammation or periodontitis. This innovative approach to systemic periodontal disease risk profiles, combining both ML and up-to-date explainability algorithms, paves the way for new periodontal health prediction strategies

Prevalence of sensitive teeth and associated factors: a multicentre, cross-sectional questionnaire survey in France

International audienceAbstract Background As far as we know, little data, whether obtained from self-administered questionnaires or upon dental clinical examination, has been published on the prevalence of sensitive teeth (ST) in the French adult population. The objectives of the present work were to estimate ST prevalence and characteristics in the general population of France and to explore the associated factors. Method A multicentre cross-sectional study was conducted between November 2011 and March 2013 in six French cities. Adult passers-by in public places were invited to answer an electronic questionnaire on a tablet computer. Only people who declared having at least one natural tooth were included in the study. A logistic regression model was used for the multivariate analysis. Results The prevalence of ST during the previous 12 months reported by the sample of 2413 participants was 42.2% [95% CI: 40.2–44.1%]. The final logistic regression model showed significant statistical associations between ST and female gender, use of tobacco, consumption of soft drinks, limited access to oral care and poor oral hygiene habits ( p < 0.05). Conclusions This study provides prevalence data on ST in a general population in France, which seems to remain high despite the existence of many therapies. It should alert professionals to a clinical manifestation that is becoming increasingly prevalent and that they will have to take into consideration to help reduce the discomfort arising from it