EMC - Odontologie最新文献

Periodontal diseases are inflammatory lesions resulting from a bacterial aggression in the dental-gingival area; they are modulated by the host's immunologic factors that determine disease progression. Clinical examination must seek for all bacterial factors, together with the general and environmental factors that are likely to influence the disease. The equipment required for this examination is simple but it must provide accurate and precise data for the semeiotic diagnosis; this diagnosis should be compared with current data using periodontal classifications, for therapeutic and prognostic considerations. Chronological analysis is performed afterwards, at the doctor's office, beginning by the reason for consulting; then the patient questioning which allows determining the disease risk factors and oral health status. The physical examination is performed on the dentist's chair, collecting all local environmental factors likely to induce or aggravate the periodontal disease; then an accurate periodontal status assessment is performed to determine the time of symptoms beginning and their progression rate; this assessment includes the evaluation of the superficial periodontium (inflammation, type of periodontium…) and that of the deep periodontium (probing, bleeding, furcations assessment).

Many therapeutic options may be considered for edentation. Most of the time, fixed partial denture (the so-called “bridge”) is the choice, since this procedure complies with aesthetic, functional and psychological consideration. Fixed partial denture is a therapeutic option that allows replacing one or several missing teeth; the procedure may consist in a small bridge elaboration, but it may also refer to important rehabilitation including both arcades. In addition to standard realisations, the development of implant techniques, the availability of novel material and the improvement in pasting procedures have allowed an overall more conservative approach based on the preservation of the tooth. The current paper is aimed at providing a simplified guide describing the various types of bridges that may currently be implemented, together with their indications and elaboration specificities.

Current principles for preparing dental cavities favor the preservation of dental tissues. Treatments have to be the less mutilating possible; only cavitary lesions require restoration. Thus, the current concept is a prophylactic model, preservative or “medical”. This has become possible after the development of adhesive techniques that allow high-quality biomechanical and biological integration. Tooth preparation consists only in curetting the entire pathological dental tissues. The tissues that are only affected by the decay (the second layer according to Fusayama) will be conserved as much as possible, and re-mineralized. Caries eviction remains mechanically realized, although some recent tooth preparation process present undeniable clinical advantages, allowing tooth conservation. Biological considerations significantly restrain the mechanical principles which dominated in the past for metallic restorations: whenever adhesion is possible, it ensures retention, stability and sustentation. Adhesive fillings are thus the best techniques according to the preservative criteria. Amalgam will be selected secondarily, and even then, preparation of the cavities has to be as preservative as possible.

Although whitening of depulped teeth is an ancient therapy, today the use of this procedure has increased substantially; it is based on two types of bleaching agents: hydrogen peroxide, and sodium perborate. External cervical resorptions (ECRs) are complications that may occur sometimes (3.9% to 9.7% reported rates in published studies). The aetiology is complex, probably multifactorial, imperfectly known, and many hypotheses have been proposed to explain their occurrence (antigen-antibodies reaction to dentin denaturation, irritation and periodontal lesion, bacterial contamination, direct intervention within the osteoclastic differentiation procedure). Several combined parameters seem to be involved in ECR occurrence. Overall ECR classification includes: vulnerability factors (anatomy of the cementoenamel junction, history of dental events such as traumas, or therapies such as orthodontic procedures or surgery), and promoting factors (related to the endodontic therapy and/or to the whitening procedure protocol). It should be noticed that the use of hydrogen peroxide as active agent is a necessary but non sufficient condition for ECR triggering. The aim of the present paper is to highlight the aetiopathogenic mechanisms of those ECRs occurring consecutively to internal whitening in order to better identify the factors on which the practitioner may act to prevent their occurrence.

Improved materials and equipments allow today creating cavities for the implementation of metallic inlays and onlays, less mutilating, more aesthetic, and long-lasting in a restoration context. The different operating stages and the specific equipment for the preparation of the cavities for intra-coronary inlay and extra-coronary onlay, together with original variants, are described. In such restorations, prosthetic creation necessitates some caution in fixing optimization; the specificity of the fixing procedure is detailed in the final part.

Research for protocols supporting haemostasis and cicatrisation is a recurrent problem in all types of surgery. Platelet concentrates, as cytokines-enriched biological adhesives constitute some novel research fields. The first generation of these surgical additives, generally named cPRP (concentrated platelet-rich plasma), come from the autologous fibrin adhesives technologies. The different kinds of cPRP were tested in many clinical situations, particularly in oral and maxillofacial surgery. Moreover, the second platelet concentrate generation, the PRF (platelet-rich fibrin), offers the more efficient clinical applications. Indeed, PRF induces accelerated tissue healing owing to the development of effective neovascularization, accelerated wound closing with fast cicatricial tissue remodelling and almost total absence of infectious events. Platelet concentrates for topical use, particularly the PRF, thus represent some new complementary therapeutic additives, provided its real effects are impartially and strictly evaluated.