A procedure for modifying the occlusal surface of an all cast implant restoration

dure for modifying restoration

the occlusal

Thomas A. Brown, DMD,a Mary Ann Anuszkiewicz, Baylor College of Dentistry, Dallas, Tex. A patient presented a failed maxillary fixed partial denture opposing a two-unit all-cast implant prosthesis. After removal of the failed restoration, it became evident that the posterior interocclusal distance was excessive and that the posterior occlusal plane needed to be raised before a satisfactory replacement fixed partial denture could be made. Correcting this situation by remaking the implant prosthesis could be time-consuming and costly. A satisfactory

DMD,b

surface and Ronald

of an all cast D. Woody,

DDS@

alternative solution was to make and solder a cast overlay to the existing implant prosthesis to correct the occlusal plane. PROCEDURE 1. After the failed maxillary fixed prosthesis is removed, make impressions of existing arches and mount the casts in an articulator to the correct occlusal relationship (Fig.

aResident, Graduate Prosthodontics. bPrivate Practice, Pittsburgh, Penn. CProfessorand Director, Graduate Prosthodontics. 18/4/38584

1). 2. Wax an overlay on the occlusal surface on the cast of the mandibular implant to the correct occlusal plane, sprue, and cast (Figs. 2 and 3). 3. Remove the existing implant prosthesis from the mouth by loosening the screws.

Fig. 1. Mounted casts show excessive space and improper occlusal plane.

Fig. 3. Occlusal casting corrects the occlusal plane shown on cast.

Fig. 2. Wax applied to occlusal surface of implant thesis on cast.

Fig. 4. Mounted casts made after corrected implant replaced show the corrected occlusal plane.

THE

JOURNAL

OF PROSTHETIC

DENTIS’TRY

pros-

was

555

TIPS

4. Fit the overlay casting to the implant prosthesis and solder it in place. 5. Reinsert the modified implant prosthesis and make new impressions and jaw relation records for fabrication of the maxillary fixed partial denture (Fig. 4).

Reprint requests to:

Making a provisional crown removable partial denture.

a clasp

Steven

R. Gordon,

under

FROM

OUR

READERS

DR. RONALD D. WOODY GRADUATE PROSTHODONTICS BAYLOR COLLEGE OF DENTISTRY 3302 GASTON AVE. DALLAS, TX 75246

of an existing

DMDa

Boston University, Goldman School of Graduate Dentistry, Boston, Mass.

New crowns are often planned for clasped abutment teeth of an existing removable partial denture. However, maintaining function of the removable partial denture while the new crowns are being made can be a problem if provisional crowns do not incorporate the rest seats, guiding planes, and undercuts needed for clasping. Using a prefabricated provisional crown is ineffective in this situation. Alternatively, a provisional crown can be custommade with a conventional ‘Lblock” technique, but difficulty is encountered in trying to fit it to the clasp. The provisional crown will often be undercontoured, resulting in space between it and the clasp. This article describes an alternate technique for constructing well-fitting provisional crowns under existing removable partial dentures.

PROCEDURE

1. Lubricate the acrylic resin sections of the existing removable partial denture. 2. Mix tooth-colored acrylic resin as if for a “block” technique for making a provisional crown, place the acrylic resin on the prepared abutment tooth, and seat the existing removable partial denture completely. Have the patient close into centric occlusion (Fig. 1). 3. As the acrylic resin is setting, repeatedly remove and reseat the removable partial denture to prevent the acrylic resin from engaging tooth undercuts adjacent to the preparation. The acrylic resin will attach to undercuts in the removable partial denture. 4. When the acrylic resin has polymerized, grind out 0.5 mm to 1 mm from the inner surface of the acrylic resin mass. Mix additional acrylic resin for relining the planned provisional crown, and place it in the crown. Reseat the removable partial denture completely. Care-

aAssociateProfessor,Department of Prosthodontics. 10/4/38586

Fig. 1. RPD has been seated over acrylic resin block and patient has closed in centric occlusion.

Fig. 2. Excess acrylic resin removed to allow separation of provisional crown from RPD framework.

SEPTEMBER

1992

VOLUME

68

NUMBER

3