A

A solid bar splint for open-tray implant impression technique

Brian Myung W. Chang, DDS,a and Robert F. Wright, DDSb

University of Nebraska College of Dentistry, Lincoln, Neb; Harvard School of DentalMedicine, Boston, Mass

The passive fit of an implant-supported prosthesis isessential to long-term treatment success. Prosthesis mis-fit is likely to increase the incidence of prosthetic failures,such as screw loosening, fracture of implant restorations,or adverse loading to implants.1-6 One of the most im-portant steps for a passive fit is an accurate impression.

The direct impression technique, which uses squaretransfer copings with an open tray, may offer greatertransfer precision due to the splinting stability.7,8 Assifet al8 investigated the accuracy of direct implant im-pression techniques with the use of various splintingmaterials and found that more accurate results wereobtained by using techniques in which autopolymeriz-ing acrylic resin or impression plaster was used as asplinting material.

Autopolymerizing acrylic resin is commonly used in-traorally to join impression copings during the open-tray implant impression technique. However, distortioncan result from the residual polymerization shrinkage ofthe resin used for splinting.9 The use of a solid bar maydecrease the amount of polymerizing shrinkage due tothe smaller amount of acrylic resin needed. In addition,there is improved efficiency and a reduction of chairtime. This article describes the direct impression tech-nique using square transfer copings splinted with a solidacrylic resin bar and autopolymerizing resin.

PROCEDURE

1. Secure the square impression copings (Nobel BiocareAB, Goteborg, Sweden) on the implants (NobelBiocare AB) and abutments (Nobel Biocare AB)(Fig. 1).

2. Prepare a solid bar made from vacuum-formedmaterial (Clear ThermoForming Material, 0.120inch; Henry Schein Inc, Melville, NY) to fit betweenthe 2 impression copings prior to making the impres-sion. Apply autopolymerizing acrylic resin (GCPattern Resin; GC America Inc, Chicago, Ill) tothe 0.5-mm gaps between impression copings andthe solid bar using the paint-on brush technique(Fig. 2).

aAssociate Professor and Director, Predoctoral Implant Program,University of Nebraska College of Dentistry.

bAssociate Professor and Director, Graduate Prosthodontics, HarvardSchool of Dental Medicine.

J Prosthet Dent 2006;96:143-4.

UGUST 2006

3. Make the definitive impression at least 15 minutes af-ter the last application of autopolymerizing acrylicresin to avoid the peak of the chemical reaction ofthe autopolymerizing resin.

REFERENCES

1. Kohavi D. Complication in the tissue integrated prostheses components:

clinical and mechanical evaluation. J Oral Rehabil 1993;20:413-22.

2. Jemt T, Linden B, Lekholm U. Failures and complications in 127 consecu-

tively placed fixed partial prostheses supported by Branemark implants:

from prosthetic treatment to first annual checkup. Int J Oral Maxillofac

Implants 1992;7:40-4.

3. Tolman DE, Laney WR. Tissue-integrated prosthesis complications. Int J

Oral Maxillofac Implants 1992;7:477-84.

Fig. 1. Square impression copings secured on implants andabutments.

Fig. 2. Autopolymerizing acrylic resin applied to connectimpression copings and solid bar.

THE JOURNAL OF PROSTHETIC DENTISTRY 143

THE JOURNAL OF PROSTHETIC DENTISTRY CHANG AND WRIGHT

4. Kallus T, Bessing C. Loose gold screws frequently occur in full-arch fixed

prostheses supported by osseointegrated implants after 5 years. Int J Oral

Maxillofac Implants 1994;9:169-78.

5. Lundqvist S, Carlsson GE. Maxillary fixed prostheses on osseointegrated

dental implants. J Prosthet Dent 1983;50:262-70.

6. Spector MR, Donovan TE, Nicholls JI. An evaluation of impression tech-

niques for osseointegrated implants. J Prosthet Dent 1990;63:444-7.

7. Assif D, Marshak B, Schmidt A. Accuracy of implant impression tech-

niques. Int J Oral Maxillofac Implants 1996;11:216-22.

8. Assif D, Nissan J, Varsano I, Singer A. Accuracy of implant impression

splinted technique: effect of splinting material. Int J Oral Maxillofac

Implants 1999;14:885-8.

9. Inturregui JA, Aquilino SA, Rythers JS, Lund PS. Evaluation of three impres-

sion techniques for osseointegrated oral implants. J Prosthet Dent 1993;69:

503-9.

144

Reprint requests to:

DR BRIAN MYUNG W. CHANG

UNIVERSITY OF NEBRASKA COLLEGE OF DENTISTRY

40TH AND HOLDREGE STREETS

LINCOLN, NE 68683-0740

FAX: 402-472-5290

E-MAIL: bchang@unmc.edu

0022-3913/$32.00

Copyright � 2006 by The Editorial Council of The Journal of Prosthetic

Dentistry.

doi:10.1016/j.prosdent.2006.06.004

VOLUME 96 NUMBER 2