[Crestal core elevation technique--case series and literature review]

Sinus floor augmentation is the most common surgical procedure for gaining bone volume in the posterior maxilla. The purpose of this procedure is to enable implant placement un edentulous ridges. The most common techniques for sinus augmentation are: 1. Bone added osteotome sinus floor elevation (BAOSFE). 2. Crestal core elevation (CCE). 3. Lateral window technique (LWT). Since the early 80's many articles describing the successful use of different augmentation materials for sinus elevation have been published. Although many articles have been published on the lateral window technique and the osteotome technique as described by Summers, few articles have been published on the crestsal core sinus elevation technique. This technique, first described by Summers, includes the use of wide diameter osteotomes and trephine bur with a diameter of 6 m"m. This technique is implemented in situations when the available bone for implant placement is less than 6 m"m , which impairs the possibility of achieving primary stability of the implant. In those cases crestal core elevation is performed and implant placement is postponed 3-8 months later. Modification of the technique described by Summers was published by Fugazzoto, this technique is implemented concomitant with the extraction of the upper molars. The crestal core elevation technique (CCE), which is based on the BAOSFE (Bone Added Osteotome Sinus Floor Elevation), is based on the principle of hydraulic force acting on fluids and particles which transfer the vector of force to all direction, in this case the sinus membrane. The detached core of interradicular bone prior to osteotome placement and malleting significantly reduces surgical trauma to the patient especially in cases where a significant portion of the pre-disease interradicular bone remains. The concomitant placement of particulate material and a membrane at the time of tooth extraction offers the advantage of minimizing if not eliminating significant 3-dimensional alveolar resorption. In this article 3 cases treated using the crestal core elevation technique are presented. Advantages and disadvantages of the technique and indication for use will be discussed.