Forum Implantologicum, 01/2017

The rehabilitation of the posterior maxilla with an implant-supported prosthesis is often a demanding treatment for the implant surgeon. The local anatomy can be difficult due to a reduced ridge height in potential implant sites. The present clinically oriented paper discusses the three most often utilized surgical options: (i) the utilization of short implants, (ii) sinus floor elevation (SFe) with the lateral window technique, and (iii) SFe with the transalveolar osteotome technique. A thorough clinical and radiographic examination is required to choose the appropriate surgical approach, which should offer a successful outcome with high predictability and a low risk of complications. In addition, treatment should offer minimal invasiveness and morbidity, when possible. low morbidity is offered by short 6-mm implants, which are utilized when multiple implants are feasible with splinted implant crowns. A single tooth replacement with 6-mm implants in molar sites is only used in exceptional situations. In all other situations, SFe is required. Both surgical techniques are well documented, but the transalveolar osteotome technique is utilized less frequently, since it requires a ridge height of 5-8 mm and a flat morphology of the sinus floor. whenever possible, a simultaneous implant placement is performed to avoid a second surgery. For that, sufficient primary stability is important, which can be optimized with tissue level implants. In addition, grafting with a composite graft is preferred, which includes locally harvested autogenous bone chips mixed with a low-substitution bone filler. The various treatment options are discussed and documented with case reports. Schlagwörter: posterior maxilla, sinus floor elevation, short implants, transalveolar technique, lateral window technique, composite graft

This article focuses on the surgical and prosthodontic options for implant placement in the posterior mandible. The authors draw on the existing literature and their 20 years of experience to describe the management of this anatomical region. Contemporary implant dentistry involves established rehabilitation strategies that satisfy the criteria of safety, predictability and short treatment duration in a cost-effective way. Schlagwörter: Dental implants, posterior mandible, partial edentulism, fixed partial denture, implant surgery

Different design configurations may be possible for implant-supported fixed dental prostheses (FDps) in the edentulous posterior maxilla. The most appropriate prosthesis design is selected according to the clinical condition. prosthetic planning allows for the selection of the appropriate number of implants and for their appropriate design and dimensions. Certain prosthetic options, such as a shortened dental arch and a cantilever, allow for the use of a reduced number of implants. The selection of reduced-diameter implants and short implants can present a treatment option to avoid bone augmentation procedures in appropriate situations. each implantprosthodontic design has its advantages and disadvantages. Schlagwörter: Dental implant, prosthodontic design, posterior, edentulous, maxilla

Implant connectors are intricate pieces of machinery that are designed to withstand functional loads during mastication. In mechanical terms these loads take the form of continuous streams of back and forth stress applications. yet while the vast majority of implant-borne restorations bear these stresses without any detrimental effects, in some instances (in the order of a few percent) screw loosening and/or fracture will occur. hence one may reasonably ask why such mishaps take place and how they can be prevented. The answer lies in a thorough understanding of the way a screw-fastened connector works - more specifically what a clinician should do or be careful of when screw-tightening a restoration onto an implant. The primary function of a screw is not to bear all the stresses applied. To the contrary, by virtue of its clamping action, the screw should distribute the load onto carrier surfaces. Screw mechanics in dynamic environments center on the concepts of 'pretension' (inside the screw) and the corresponding 'preload' (of the surfaces) as well as how they decay over time once the connector is placed in function. The essential objective of any connector design is to minimize not the absolute value but the stress amplitude during cyclic loading consequent to mastication. Therefore, for the clinician, the objective is to permit the connector - the screw - to function under optimal conditions. This translates into establishing tight contact between the carrier surfaces machined into the implant head and that of the prosthetic component. Further, these surfaces must be firmly clamped so that the force transfer between them is maximized and the stress inside the screw is relieved. Schlagwörter: Implant, connector, screw, fatigue, stress, fracture, screw loosening