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journal of prosthodontics 2009 - PDF 6

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					A nontraumatic method for ceramic crown removal
Stefano Ardu, DMD,a and Raymond Perroud, DMDb Dental School, University of Geneva, Geneva, Switzerland

1 Maxillary left central incisor has ceramic crown luted with provisional cement. Vinyl polysiloxane adhesive applied to facial crown surface. When a ceramic crown is luted with provisional cement and must be removed, the risk of fracturing margins or chipping the restoration during removal may increase if a common crown-removing forceps is used. Therefore, authors advocate the use of a quadrant disposable tray1 and an impression material,2 together with its adhesive.3 This article describes a procedure that allows the use of a minimal amount of impression material, resulting in an inexpensive method which allows for easy and nontraumatic removal of ceramic crowns. The mechanical advantage of this technique is that the pressure at the ceramic shoulder (which is usually the weakest part of a ceramic crown) is reduced, due to the fact that the area of stress created during the crown removal is shared along the crown axis.
a

2 Impression material application using quadrant disposable tray.

In this manner, the risk of marginal chipping is reduced. This technique is especially suitable for ceramic crowns where the ceramic shoulder is thin.

REFERENCES
1. Grant BE, Tjan AH. Tensile and peel bond strengths of tray adhesives. J Prosthet Dent. 1988;59:165-8. 2. Ping Chaing BK. Polymers in the service of prosthetic dentistry. J Dent 1984;12:20314. 3. Lane DA, Randall RC, Lane NS, Wilson NH. A clinical trial to compare double-arch and complete-arch impression techniques in the provision of indirect restorations. J Prosthet Dent 2003;89:141-5. Corresponding author: Dr Stefano Ardu Ecole de Médecine Dentaire, Université de Genève Rue Barthélemy-Menn 19, CH-1205 Genève SWITZERLAND Fax: +41 22 3829990 E-mail: stefano.ardu@unige.ch Copyright © 2009 by the Editorial Council for The Journal of Prosthetic Dentistry.

PROCEDURE
1. Apply the vinyl polysiloxane adhesive (VPS Tray Adhesive; 3M ESPE AG, Seefeld Germany) on the labial or buccal and palatal or lingual crown surfaces (Fig. 1). 2. Apply the impression material (Impregum Garant L Duo Soft; 3M ESPE AG) using a quadrant disposable tray (Kwik Tray; Kerr Corp, Orange, Calif ) (Fig. 2). 3. When the impression material has polymerized, remove the quadrant tray and the crown, which has adhered to the impression material.

b

Lecturer, Division of Preventive Medicine. Senior Lecturer, Division of Preventive Medicine.

(J Prosthet Dent 2009;101:285)

Ardu and Perroud


				
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