Quintessence Journals

51 isolation through the dental dam) and 2) a biological parameter (depending on the biologic width). Three different clinical situations and three different therapeutic approaches are identified (1 st , 2 nd , and 3 rd , respectively): coronal relocation of the margin , surgical exposure of the margin, and clinical crown lengthening. The latter is associated with three further operative sequences: immediate, early, or delayed impression taking. The different therapeutic options are described and illustrated by several clinical cases. The surgical-restorative approach, whereby surgery is strictly associated with buildup, onlay preparation, and impression taking is particularly interesting. The restoration is cemented after only 1 week. This approach makes it possible to speed up the therapy by eliminating the intermediate phases associated with positioning the provisional restorations, and with fast and efficient healing of the soft marginal tissue. Abstract The aim of this article is to analyze some of the issues related to the adhesive restoration of teeth with deep cervical and/or sub-gingival margins in the posterior area. Three different problems tend to occur during restoration: loss of dental substance, detection of subgingival cervical margins, and dentin sealing of the cervical margins. These conditions, together with the presence of medium/large-sized cavities associated with cuspal involvement and absence of cervical enamel, are indications for indirect adhesive restorations. Subgin-gival margins are associated with biological and technical problems such as difficulty in isolating the working field with a dental dam, adhesion procedures, impression taking, and final positioning of the restoration itself. A new classification is suggested based on two clinical parameters: 1) a technical-operative parameter (possibility of correct 52 well-integrated conservative restoration that can be retreated at a later date, either endodontically or for reconstruction. 7 Therefore, as the " therapeutic arsenal " for rehabilitation in the posterior areas has changed, there is now an overall prevalence of adhesive restorations and their different application techniques (direct, semi-direct, indirect). Silver amalgam is no longer indicated, except in certain clinical applications. Gold onlays maintain their effectiveness in cases of minimum inter-occlusal spaces (gold being the only material with the physical-mechanical properties suitable for thicknesses less than 1 mm) or in parafunctional patients. The number of single elements requiring pros-thetic restoration has been considerably reduced and therefore the line between conservative treatment and replacement has changed. Finally, with regard to seriously affected teeth, the development of implant techniques and evidence regarding osseointegration and guided bone re-generation …