Tylman Fixed Prosthodontics Pdf 84

Unconventional pontics in fixed partial dentures Mansi Manish Oswal1, Manish Sohan Oswal2 1 Assistant Professor, D.Y. Patil Dental School, Lohegoan, Pune, Maharashtra, India2 M.D.S, Prosthodontics, D.Y. Patil Dental School, Lohegoan, Pune, Maharashtra, India Date of Web Publication25-Oct-2016

The fixed-removable prosthesis resembles a flangeless denture that is retained solely by several osseointegrated implants. There is no contact between the prosthesis and the tissues of the alveolar ridge.

The original design of the fixed-removable prosthesis was developed by Swedish investigators using the two-stage endosseous implant system developed by Brånemark. The prosthesis consisted of a gold alloy framework attached to the copings of the implant. Acrylic resin denture teeth were arranged on the framework and secured with acrylic resin [17]. The fixed-removable prosthesis represented a unique aspect of prosthodontics reconstruction for edentulous arches, since implants were situated in the anterior region and the posterior sections of the framework were cantilevered from the anterior portion of the framework (Fig. 1). The length, height, and width of the cantilever are crucial in minimizing the amount of deformation of the prosthesis (Fig. 2). According to Glantz, the mount of deformation of the cantilever is directly proportional to the cube of the length and inversely proportional of the width and the cube of the height of the cantilever [18]. In addition, there is a direct relation between the amount of deformation and the force of the occlusion (loading force) as well as an inverse relation with the modulus of elasticity of the material to be used for the framework. This relationship can be expressed in the following equation:

According to Zarb and Jansson, frameworks in fixed prostheses could be designed in one of the two ways: (1) where metal frameworks comprised the bulk of the prostheses, and artificial teeth and minimal denture bases were the only non-metallic components. (2) Implant fixed prostheses consisting mostly of acrylic resin denture bases (wraparound design) and artificial teeth, with minimally sized metal frameworks [17].

Implant treatment was based on basic prosthodontics principles that included preliminary and definitive impressions, jaw relation records, wax try-in, metal framework try-in, and insertion of definitive prostheses. Frameworks were fabricated according to the following criteria: bulk for strength, adequate access for oral hygiene procedures, minimal display of metal on the facial and occlusal surfaces, and strategic thinning of implant frameworks to allow for retention of acrylic resin denture teeth and denture basses [28].

A well-accepted principle of restorative dentistry is that the final restoration can be only as accurate and well adapted as the final impression. The clinical challenge is to provide an a