Principes généraux de préparation des dents en vue de leur restauration

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.