Planned Retreatment

At the original treatment-planning stage, retreat-ment should be considered. This consideration may need to be general rather than specific because of difficulties in accurately predicting the pattern of future dental disease. Occasionally, however, a prosthesis is designed to accommodate the eventual failure of a doubtful abutment (Fig. 32-31). With a little foresight, survey contours can already be incorporated in the retainers of an FPD to accommodate a future removable partial denture (RPD) in the event of a terminal abutment loss. Similarly, accommodations can be made for future occlusal rests by deliberately increasing occlusal reduction during

Fig. 32-29. Osseous defects (arrows) within 2 years of the placement of this FPD. (Courtesy Dr. J. Keene.)

tooth preparation and using metal occlusal surfaces. Furthermore, proximal boxes can be incorporated if it is anticipated that a nonrigid (dovetail) rest could simplify future retreatment (see Fig. 32-31).

When tooth preparations are conservative, margins are supragingival, and complicated FPD designs are avoided, replacement dentistry can be performed in an orderly manner, as long as plaque control and follow-up care are maintained.

The key to successful fixed prosthodontic treatment planning lies in anticipating potential areas of future failure. Ideally, the design of a prosthesis should incorporate an escape mechanism to allow simple and convenient alteration to accommodate future treatment needs.

Fig. 32-29. Osseous defects (arrows) within 2 years of the placement of this FPD. (Courtesy Dr. J. Keene.)

Fig. 32-30. a "saddle" pontic should not be fabricated, because it makes plaque control impossible. However, this particular FPD was replaced after 35 years of service. B, Despite poor pontic design, there are no significant signs of ulceration. This example illustrates the variability of tissue response due to differences in host resistance.

Fig. 32-30. a "saddle" pontic should not be fabricated, because it makes plaque control impossible. However, this particular FPD was replaced after 35 years of service. B, Despite poor pontic design, there are no significant signs of ulceration. This example illustrates the variability of tissue response due to differences in host resistance.

Maxillary Rpd Design

Fig. 32-31. Anticipation of future needs. A, Four years after the restoration of an arch with periodon-tally compromised teeth. Three intracoronal rests (arrows) were fabricated to support an RPD. B, An additional rest (arrow) was included as a nonrigid connector for splinting the prostheses in the maxillary left quadrant. This rest is parallel to the others, so it will be available (if needed) for future support of a modified or new RPD. C, The lingual of the premolar incorporates the appropriate survey contour (arrow) to accommodate such a prosthesis. D, The RPD in place. Note the third intracoronal rest (arrow). E, Occlusal aspect of the fixed prosthesis. F, The FPD with the RPD in place.

Continued

Fig. 32-31. Anticipation of future needs. A, Four years after the restoration of an arch with periodon-tally compromised teeth. Three intracoronal rests (arrows) were fabricated to support an RPD. B, An additional rest (arrow) was included as a nonrigid connector for splinting the prostheses in the maxillary left quadrant. This rest is parallel to the others, so it will be available (if needed) for future support of a modified or new RPD. C, The lingual of the premolar incorporates the appropriate survey contour (arrow) to accommodate such a prosthesis. D, The RPD in place. Note the third intracoronal rest (arrow). E, Occlusal aspect of the fixed prosthesis. F, The FPD with the RPD in place.

Continued

Fig. 32-31, cont'd. G and H, External and internal aspects of the RPD. This was cast in Type IV gold, which allows the relatively easy addition of a new minor connector with conventional soldering techniques.

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