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Clermont-Ferrand, France

Brkanic T.,University of Novi Sad | Stojsin I.,University of Novi Sad | Zivkovic S.,Dental faculty | Vukoje K.,University of Novi Sad
Microscopy Research and Technique

Root canal preparation is the most important phase of endodontic procedure and it consists of adequate canal space cleaning and shaping. In recent years, rotary instruments and techniques have gained importance because of the great efficacy, speed, and safety of the preparation procedure. AIM: The aim of this research was to investigate measurement of maximal and minimal residual dentine thickness (RDT) and canal diameter after the canal preparation with different NiTi rotary files. METHODS: The research has been conducted on extracted human teeth in vitro conditions. The teeth have been divided in seven groups (20 teeth per group) depending on the kind of instruments used for root canal preparation: ProTaper, GT, ProFile, K-3, FlexMaster, hand ProTaper, and hand GT. The canals have been shaped in a crown-down manner and irrigated with 5.25% sodium hypochlorite. The roots of the teeth have been cut 1 and 3 mm from the apex. Apical preparation quality has been assessed under the polarized light microscope. RESULTS: The maximal residual dentine thickness at distance 1 mm from apex, ranged from 1.16 to 1.45 mm, and at distance 3 mm from apex, from 1.44 to 1.84 mm. The minimal dentine thickness at distance 1 mm from apex ranged from 0.52 to 0.73 mm, and at distance 3 mm from apex, from 0.66 to 0.83 mm. The canal diameters after preparation at distance 1 mm from apex ranged from 0.42 to 0.49 mm, and at distance 3 mm from apex, from 0.53 to 0.63 mm. CONCLUSIONS: There was no significant difference neither in maximal and minimal RDT, nor in canal diameters shaped with different NiTi instruments tested. All tested NiTi files have accomplished good quality preparation of apical root canal parts. © 2011 Wiley Periodicals, Inc. Source

Woda A.,Dental faculty | Woda A.,Estaing University Hospital Center | Picard P.,Estaing University Hospital Center | Dutheil F.,Estaing University Hospital Center | And 2 more authors.

Many dysfunctional and chronic pain conditions overlap. This review describes the different modes of chronic deregulation of the adaptive response to stress which may be a common factor for these conditions. Several types of dysfunction can be identified within the hypothalamo-pituitary-adrenal axis: basal hypercortisolism, hyper-reactivity, basal hypocortisolism and hypo-reactivity. Neuroactive steroid synthesis is another component of the adaptive response to stress. Dehydroepiandrosterone (DHEA) and its sulfated form DHEA-S, and progesterone and its derivatives are synthetized in cutaneous, nervous, and adipose cells. They are neuroactive factors that act locally. They may have a role in the localization of the symptoms and their levels can vary both in the central nervous system and in the periphery. Persistent changes in neuroactive steroid levels or precursors can induce localized neurodegeneration. The autonomic nervous system is another component of the stress response. Its dysfunction in chronic stress responses can be expressed by decreased basal parasympathethic activity, increased basal sympathetic activity or sympathetic hyporeactivity to a stressful stimulus. The immune and genetic systems also participate. The helper-T cells Th1 secrete pro-inflammatory cytokines such as IL-1-β, IL-2, IL-6, IL-8, IL-12, IFN-γ, and TNF-α, whereas Th2 secrete anti-inflammatory cytokines: IL-4, IL-10, IGF-10, IL-13. Chronic deregulation of the Th1/Th2 balance can occur in favor of anti- or pro-inflammatory direction, locally or systemically. Individual vulnerability to stress can be due to environmental factors but can also be genetically influenced. Genetic polymorphisms and epigenetics are the main keys to understanding the influence of genetics on the response of individuals to constraints. © 2016 Elsevier Ltd. Source

Aim and Objective: The aim of this study is to evaluate the positional changes that occur in mucogingival line following the use of subepithelial connective tissue graft (SCTG). Materials and Methods: In 19 Miller class I or II gingival recession defects, distance between mucogingival line (MGL) and cemento-enamel junction, also width of keratinized and attached gingiva, and clinical attachment level were measured. SCTG were used for covering the exposed roots. A fore mentioned parameters were repeated at 3, 6 and 12 months after surgery and alterations were measured. Paired t test was used to analyze the results. Results : MGL had been moved in coronal direction (4.39 ± 0.77 mm on average) during surgical approach. After 1 year, MGL shifted 2.11 ± 0.7 mm apically. In accordance with this apical shift, a significant increase in the width of keratinized and attached gingival width (2.89 ± 0.63 mm and 2.82 ± 0.5 mm, respectively) was seen (P < 0.05). Conclusion : MGL tended to revert back to its original position following the use of SCTG, and this reversion is accompanied with an increase in the keratinized and attached gingival width. Source

Simonis P.,University of Strasbourg | Dufour T.,Dental faculty | Tenenbaum H.,University of Strasbourg
Clinical Oral Implants Research

Objectives: The aim of the present study was to evaluate the long-term results of dental implants using implant survival and implant success as outcome variables. Methods: Of the 76 patients who received 162 implants of the Straumann Dental Implant System during the years 1990-1997, 55 patients with 131 implants were recalled 10-16 years after implant placement for a complete clinical and radiographic examination, followed by a questionnaire that examined the degree of satisfaction. The incidence of biological and technical complications has been carefully analysed for each implant. Success was defined as being free of all these complications over the entire observation period. Associated factors related to peri-implant lesions were analysed for each implant. Results: The long-term implant cumulative survival rate up to 16 years was 82.94%. The prevalence of biological complications was 16.94% and the prevalence of technical complications was 31.09%. The cumulative complication rate after an observation period of 10-16 years was 48.03%, which meant that substantial amounts of chair time were necessary following implant placement. The majority of implant losses and biological complications were concentrated in a relatively small number of patients. Conclusion: Despite a relatively high long-term survival rate, biological and technical complications were frequent. Patients with a history of periodontitis may have lower implant survival rates than patients without a history of periodontitis and were more prone to biological complications such as peri-implant mucositis and peri-implantitis © 2010 John Wiley & Sons A/S. Source

Rouers M.,Dental faculty | Antoni D.,University of Strasbourg | Thompson A.,Middlesex University | Truntzer P.,University of Strasbourg | And 8 more authors.
Practical Radiation Oncology

Purpose: Dental care is crucial after irradiation of the head and neck. This care may include dental restoration, extractions, and prosthetic implantation or prosthesis adjustment. To perform these procedures safely, dentists need to know the delivered radiation dose delivered to the relevant part of the mandible and/or maxilla. We propose a simple, fast, and useful contouring technique to aid accurate recording of radiation therapy dose to the mandible and maxilla. Methods and materials: The maxilla and mandible of 2 patients, 1 dentate and 1 edentulous, have been contoured on computed tomography planning scans. The jaw has been divided into sextants (3 segments in both the mandible and maxilla) using bony landmarks. Results: We have developed a contouring atlas to aid radiation oncologists in delineating the maxilla and mandible allowing accurate recording of dose to each sextant and meaningful communication with their dental colleagues. Conclusion: Delineation of the maxilla and mandible is important if we are to improve communication between radiation oncologists and dentists regarding radiation and risk to these structures. Our method should not increase the time to delineate the organs at risk and target volumes in the head and neck area and could improve the safety of subsequent dental treatments. © 2015 American Society for Radiation Oncology. Source

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