Fundamentals of fixed prosthodontics pages 161

Fundamentals of fixed prosthodontics pages 161 full#

Likewise, the occlusal force distributed to five posterior teeth should also not be supported by only two implants. The adjacent abutments are subjected to considerable additional force when they must support three missing teeth, especially in the posterior regions of the mouth.

In fixed prosthesis design, three adjacent pontics in the posterior regions of the mouth are contraindicated with natural abutments3 (Fig. Since implants seem to be more rigid than natural teeth, the number of pontics with implants is often increased compared to natural teeth. The number of pontics for a prosthesis is related to several factors, including the strength of the abutments (Fig. Misch developed a treatment plan sequence to decrease the risk of biomechanical overload consisting of: 1) Prosthesis design, 2) Patient force factors, 3) Bone density in the edentulous sites, 4) Key implant positions 5) Implant number, 6) Implant size, 7) Available bone in the edentulous sites and 8) Implant design.2 (Table 1) This article will consider the key implant positions for a prosthesis, when three adjacent teeth are missing in the mouth. Hence, biomechanical issues should be a primary issue in developing an implant treatment plan. Screw loosening and uncemented restorations are also complications which cause more prosthetic problems and more often than esthetic consequences of treatment. However, the primary causes of complications in implant dentistry are related to biomechanics.1 For example, early loading failures outnumber surgical healing failures, especially in soft bone, when forces are greater than usual and/or implant sizes are shorter than 10mm. Pontics often replace missing teeth, and ovate pontics are easier to develop than esthetic adjacent implant crowns.

In this scheme, implant positions were primarily controlled by the soft tissue contours of the teeth replaced. A second historical phase of treatment planning then developed, based upon esthetics.

Fundamentals of fixed prosthodontics pages 161 full#

As a consequence, distal cantilevers were often extended from anterior implants to support a full arch implant prosthesis, rather than performing bone augmentation. In the past, treatment planning for implant dentistry was primarily driven by the existing bone volume in the edentulous site.