11: Case Presentations

CHAPTER 11 Case Presentations

Alternatives for Final Framework Designs

Hybrid versus Profile Prostheses

A hybrid prosthesis is a prosthesis that replaces missing teeth and missing soft and hard tissues in a composite defect. The term hybrid prosthesis (or the Brånemark or Toronto bridge) has become synonymous with a metal-based prosthesis that replaces missing soft and hard tissues with pink acrylic and missing teeth with acrylic teeth. If the restorative dentist so chooses, pink porcelain and porcelain teeth may be substituted for the restorative reconstruction using the hybrid treatment concept.

The design of the hybrid prosthesis has evolved with the advent of new abutments such as the multiunit abutment, which allows a more natural and anatomically correct emergence of the prosthesis from the soft tissues. Today, these prostheses are referred to as profile prostheses.

The Toronto bridge was a “high water” design because the abutments available at the time were standard abutments, which, by design, were at least 0.5- to 1-mm supragingival. Therefore, the final design of the prosthesis left a gap between the intaglio surface of the prosthesis and the crest of the ridge. This type of design was functional for the edentulous mandible. When turned upside down and used for the edentulous maxilla, however, it left a lot to be desired. The gap allowed air to escape during speech and caused mispronunciation of dentoalveolar sounds. Proper pronunciation requires a palatal seal between the prosthesis and the palatal soft tissues (Figures 11-1 and 11-2).

FIGURE 11-1 The maxillary hybrid prosthesis: The existing space between the intaglio surface of the prosthesis and the soft tissues does not allow for proper phonetics in the edentulous maxillary arch.

FIGURE 11-2 The intaglio surface of the conventional hybrid prosthesis: The finish line between the metal substructure and the overlying pink acrylic is evident.

The Profile Prosthesis: Gold Framework

The intaglio surface of the profile prosthesis has a cross-section similar to a pontic tooth in a conventional fixed partial denture. Pink acrylic surrounds a metal substructure and meets the soft tissue crest with pinpoint contact. This seals the gap, and phonetics in the maxillary profile prosthesis are acceptable.

An important feature of the profile prosthesis is the design of the metal substructure. Whether gold or titanium framework is used, extension of the framework to support the overlying pink acrylic and teeth is crucial. To allow the laboratory technician to design a metal substructure with adequate extensions in both the anterior-posterior (AP) and lateral dimensions, the initial step in profile prosthesis design involves setting acceptable denture teeth. Proper extension of the metal framework permits well-supported occlusal loads, which prevents teeth from “popping off” during function.

The following section demonstrates the various steps in the fabrication of a maxilla and/or mandibular profile prostheses (Figures 11-3 to 11-17).

FIGURE 11-3 A, Clinical presentation of the “profile prosthesis” as it relates to the edentulous soft tissues. B, The maxillary profile prosthesis: The interimplant pink acrylic wraps around the metal substructure and is in pinpoint contact with the soft tissue of the maxillary ridge.

FIGURE 11-4 The pink acrylic completely wraps around the metal substructure of this profile prosthesis.

FIGURE 11-5 The initial step involved in fabrication of a profile prosthesis is proper anterior-posterior and proper vertical dimension of occlusion setup. Shown is the first wax try-in.

FIGURE 11-6 Once the patient approves the teeth setup, a putty index of the denture setup is made. Then metal framework fabrication begins.

FIGURE 11-7 In the casted framework, the relationship of the retention pins to the teeth positions in the putty index is evident, ensuring proper support of the teeth under occlusal load.

FIGURE 11-8 With use of the putty index, this mandibular framework design clearly shows proper anterior extension for tooth support.

FIGURE 11-9 The severe posterior resorption of the maxillary ridge does not allow any landmark to assist the laboratory technician in extending the framework. Use of the putty index permits this maxillary framework design to have proper extensions.

FIGURE 11-10 Putty index relating the teeth position to the metal framework.

FIGURE 11-11 Proper positioning of the support rods for support and retention of the maxillary teeth.

FIGURE 11-12 Second wax try-in using the completed framework: Aesthetics, occlusion, and phonetics are evaluated during the second wax try-in prior to processing the profile prosthesis.

FIGURE 11-13 Intaglio surface of the profile prosthesis during second wax try-in.

FIGURE 11-14 A, Completed mandibular profile prosthesis. B, Prosthetic screw access holes will be sealed for oral hygiene purposes.

FIGURE 11-15 Intaglio surface of the completed maxillary profile prosthesis: The interimplant acrylic meets the patient’s soft tissues with a pontic-like, pinpoint contact.

FIGURE 11-16 Completed maxillary profile prosthesis.

FIGURE 11-17 Delivered maxillary profile prosthesis with proper palatal seal, which allows correct pronunciation of dentoalveolar sounds.

Titanium Framework: Procera Implant Bridge

A 43-year-old woman with nonrestorable maxillary dentition presented for definitive treatment of her maxilla with an implant-supported prosthesis. Her clinical evaluation resulted in the following findings:

1. Partial maxillary edentulism

2. Presence of mid-composite defect

3. Favorable transition line

4. Presence of zones I and II on radiographic evaluation

(Figures 11-18 to 11-20)

FIGURE 11-18 Partially edentulous maxillary dentition restored with a removable partial denture. Presence of long teeth suggests the existence of mild composite defect.

FIGURE 11-19 Hidden transition line during animation suggests a positive outcome for a final profile prosthesis.

FIGURE 11-20 Presence of zones I and II allows adoption of the tilted implant treatment concept.

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Tags: Implant Treatment Planning for the Edentulous Patient

Jan 7, 2015 | Posted by mrzezo in Implantology | Comments Off

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