An alternative procedure for positioning a prefabricated extracoronal at tachment in a removable partial denture Tuncer Burak Ozcelik, DDS, PhD,a and Burak Yilmaz, DDS, PhDb Baskent University, Faculty of Dentistry, Ankara, Turkey; The Ohio State University, College of Dentistry, Columbus, Ohio A prefabricated attachment for support and retention of a removable partial denture in which the patrix and matrix components are positioned outside the normal contour of the abutment tooth is considered an extracoronal attachment.1,2 Ball retentive prefabricated extracoronal attachments are commonly used and are provided in a wide range of dimensions and retentive matrix materials.3 As a result, interocclusal and buccolingual space are critical clinical factors when selecting the desired ball attachment and retentive matrix.4 Problems can occur when an interocclusal space deficiency is not recognized until well into the treatment process; this can result in an undesirable situation for the patient and clinician. Adequate interocclusal space is necessary to accommodate the height of the ball attachment, the retentive matrix housing seated onto the attachment, and the space over the matrix housing to allow a sufficient thickness of acrylic resin for the retention of the tooth or teeth in the prosthesis.5 Optimal positioning of the attachment should be in harmony with the path of insertion of the planned prosthesis for a successful clinical outcome.6 A simple and cost-effective method for mounting a prefabricated extracoronal ball attachment for a removable partial denture (RPD) with the use of a counter gauge is de-
scribed. The counter gauge is a tool with stainless steel probes which duplicate and transfer patterns of objects. This method is an alternative to the silicone index technique,2,5 as no additional materials are required and laboratory time is reduced.
PROCEDURE 1. Pour definitive casts with type IV dental stone (Galaxy; Lafarge Prestia Co Ltd, Cholburi, Thailand), and fabricate removable dies with a pin system (Ultipins; Lafarge Prestia Co Ltd). 2. Mount definitive casts in a semiadjustable articulator (Stratos 100; Ivoclar Vivadent, Schaan, Liechtenstein) with the use of maxillomandibular relationship records and facebow transfer (UTS facebow; Ivoclar
Vivadent, Schaan, Liechtenstein). 3. Complete the anatomic full contour waxing (GEO Classic modeling wax, blue; Renfert GmbH, Hilzingen, Germany) of the prepared abutments. Arrange the first artificial acrylic resin tooth (Yamahachi acrylic resin teeth; Yamahachi Dental Mfg Co, Gamagori City, Japan) for the RPD on the crest of the edentulous alveolar ridge for occlusal plane development to identify correct attachment placement (Fig. 1). 4. Mark the middle of the buccal/ lingual surface projection of the artificial teeth and distal extension edentulous alveolar ridge on the definitive cast with a pencil. 5. Use a counter gauge (Empire Level Mfg Corp, Mukwonago, Wis) and pencil lines to record the position of the artificial teeth on the defini-
1 Anatomic contour waxing of prepared abutment teeth and artificial tooth on definitive cast for development of occlusion.
Assistant Professor, Department of Prosthodontics. Postdoctoral Fellow, Department of Prosthodontics, Implant Prosthodontic Fellow, Department of Restorative and Prosthetic Dentistry.
a
b
(J Prosthet Dent 2008;100:240-241)
The Journal of Prosthetic Dentistry
Ozcelik and Yilmaz
241
September 2008
A
B
2 A, Counter gauge placed for recording position of artificial tooth. B, Counter gauge replaced on definitive cast as guide for position of patrix. tive cast, and ensure that adequate space is available for the prefabricated extracoronal ball attachment (OT Strategy castable vertical attachment; Rhein83, Bologna, Italy) on the counter gauge by inspection (Fig. 2, A). 6. Remove the artificial teeth (Yamahachi acrylic resin teeth; Yamahachi Dental Mfg Co) from the definitive cast. Cut back the wax around the abutment teeth to provide space for the porcelain/metal substructure and for development of appropriate occlusion with the opposing arch. 7. Place the definitive cast on the dental surveyor (AF200; Amann Girrbach AG, Koblach, Austria). Replace the counter gauge (Empire Level Mfg Corp) on the left or right distal extension edentulous arch following the pencil lines which were marked previously on the definitive cast. Position the patrix pattern (OT Strat-
egy castable vertical attachment; Rhein83) in relation to the wax pattern by means of special mandrel (Rhein83) in the dental surveyor with the guidance of the counter gauge (Fig. 2, B). Position the patrix pattern (OT Strategy castable vertical attachment; Rhein83) of the other side with the same technique. 8. Invest and cast the wax patterns with conventional laboratory procedures.5
REFERENCES 1. Rosenstiel SF, Land MF, Fujimoto J. Contemporary fixed prosthodontics. 4th ed. St Louis: Elsevier; 2006. p. 805-29. 2. Sherring-Lucas M, Martin P. Attachments for prosthetic dentistry: introduction and application. London: Quintessence; 1994. p. 64, 69, 70. 3. Burns DR. Mandibular implant overdenture treatment: consensus and controversy. J Prosthodont 2000;9:37-46.
4. Stamos DE, Gutmann JL. Survey of endodontic retreatment methods used to remove intraradicular posts. J Endod 1993;19:366-9. 5. Preiskel HW. Overdentures made easy. A guide to implant and root supported prostheses. London: Quintessence; 1996. p. 105-37. 6. Phoenix RD, Cagna DR, DeFreest CF. Stewart’s clinical removeable partial prosthodontics. 3rd ed. Chicago: Quintessence; 2003. p. 507-17. Corresponding author: Dr Burak Yilmaz Baskent Universitesi Dis Hekimligi Fakultesi Bahcelievler, 06490, Cankaya Ankara TURKEY Fax: 90-312-2152962 E-mail:
[email protected] Acknowledgements The authors thank Paul Tanner from the University of Utah for his valuable contribution to this manuscript. Copyright © 2008 by the Editorial Council for The Journal of Prosthetic Dentistry.
Receive Tables of Contents by E-mail To receive tables of contents by e-mail, sign up through our Web site at http://www.journals.elsevierhealth.com/periodicals/ympr. Instructions Log on and click “Register” in the upper right-hand corner. After completing the registration process, click on “My Alerts,” then “Add Table of Contents Alert.” Select the category “Mosby” or type The Journal of Prosthetic Dentistry in the search field and click on the Journal title. The title will then appear, and having already completed the Registration process, you may add tables of contents alerts by accessing an issue of the Journal and clicking on the “Add TOC Alert” link. You will receive an e-mail message confirming that you have been added to the mailing list. Note that tables of contents e-mails will be sent when a new issue is posted to the Web site.
Ozcelik and Yilmaz