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Prosthetic Management of the Sinus Graft Case Ira D. Zinner, DDS, Stanley A. Small, DDS
MSD
he relationship of pretreatment prosthodontics to a favorable prognosis requires a team approach between the prosthodontist, surgeon, and dental technician. Each member of this team should understand the long-term goals of treatment. The prosthodontist should be the director of this team, since implant placement depends on the planned subsequent prosthesis.
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Assessment and Treatment Planning Prosthodontic procedures are necessary prior to placement of endosseous root-form implants and sinus augmentation surgery. At the initial patient interview, the prosthodontist should discuss with the patient his or her treatment goals in terms of esthetics and function. If the patie1'lt reports that he or she is a smoker, it becomes necessary to explain that these are risk factors that can contribute to implant failure.! Ideal treatment goals should be explained to the patient, with reference to either removable or implant-supported fixed-detachable prostheses, as well as the risks and benefits of various treatment modalities, which may include non treatment. An assessment of the patient's expectations and his or her ability to undergo an extended treatment modality are elicited at this interview. A complete set of right-angled radiographs, a panoramic radiograph, and a reformatted computerized tomography (CT) scan of the maxilla are taken fol
lowed by a clinical examination of the prospective patient. All of these should be part of the patient's permanent chart. Maxillary and mandibular diagnostic casts are made and mounted on an articulator using verified maxillomandibular recordings. These casts are duplicated and mounted, and a diagnostic waxup of the anticipated outcome is created. An impression is made from this waxup, and a cast is poured and duplicated. One cast is employed to construct a provisional prosthesis that is used from before first-stage surgery through second-stage surgery. A second cast is used to fabricate a surgical template as an aid for the surgeon to optimally position the implants. Consultation with the surgeon is necessary prior to template construction. This template employs grooves or other markers as guides for the placement of the implants. It also has an open buccal surface to prevent interference with the surgical sinus augmentation procedures.2 During the diagnostic waxup, CT scan evaluation, and surgical template fabrication, the implant team should plan to place one implant per tooth being replaced, either in the sinus graft alone or in conjunction with the residual alveolar bone. No cantilevers should be used.3 The maxillary bone is not as dense as the mandibular parasymphyseal bone, and the torquing stresses from cantilevers during the functional and parafunctional mandibular movements may cause screw loosening, screw breakage, and unwanted torquing on the implants.
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