Design of a Cast Bar Reinforced Provisional Restoration for the Management of the Interim Phase in Implant Dentistry
Sebastian Saba, DDS, Cert. Prosth.
MeSH Key Words:dental implants; dental prosthesis design; dental restoration,
The management of the interim phase in dental implant therapy is usually the most difficult phase for both the patient and the clinician.1 Certain clinical conditions, such as long-span edentulous regions, loss of interocclusal space, and lack of posterior support, present problems for conventional fixed provisional restorations. The long-span and traumatic occlusions allow flexure in the provisional bridge, which results in fractures and washout of the cementing medium and associated complications to the natural abutments and implant recipient sites.
Provisional restorations may be reinforced with a variety of materials to avoid fracture. Youdelis and Faucher2 report a technique that uses stainless steel wire to reinforce an autopolymerizing acrylic resin provisional restoration. Binkley and Irvin3 describe heat-processed provisional restorations reinforced with a 16- or 18-gauge cast metal framework.
In order to establish the proper vertical dimension of occlusion and protect the surgical site of the implant during the regenerative and osseointegration phases, a cast metal bar reinforced provisional restoration may be fabricated. The cast bar provides enough rigidity to prevent flexure in the bridge, thus avoiding fractures and cement washout. The added rigidity of a thick cast bar over the implant surgical site allows the pontic region of the provisional restoration to be relieved for post-surgical healing without compromising the patient. The provisional restorations allow for an assessment of the vertical dimension of occlusion and the protection of the surgical site, permitting an uncomplicated interim phase of treatment.4
Study models were mounted and a diagnostic wax-up generated to help identify the occlusal pathology and diagnose the interocclusal violation and esthetic limitations. These limitations can be corrected in the design of the provisional restoration. The wax-up also simplifies communication of treatment plan options to the patient and helps him or her make a better informed decision. (Figs. 3, 4, and 5).
This long-span, long-term provisional restoration allows the management of implant surgery phases in a predictable fashion while maintaining the patient in a comfortable, problem-free fixed provisional stage. Occlusal stability and vertical dimension were maintained because of greater wear resistance of the hardened laboratory-processed acrylic and the rigid cast bar reinforcement.
After an acceptable period of time, the occlusion and contours developed in the provisional restoration were duplicated in the final restoration.
Dr. Saba has a private practice in prosthetic and implant dentistry in Montreal, Que. He is also a lecturer at the Faculty of Dentistry at McGill University.
Reprint requests to: Dr. Sebastian Saba, 3550 Côte Des Neiges, Suite 240, Montreal, QC H3H 1V4.
1. Moscovitch M, Saba, S. The use of a provisional restoration in implant dentistry: a clinical report. Int J Oral Maxillofac Implants 1996; 11:395-9.
2. Youdelis RA, Faucher R. Provisional restorations: an integrated approach to periodontics and restorative dentistry. Dent Clin North Am 1980; 24:285-303.
3. Binkley CJ, Irvin PT. Reinforced heat-processed acrylic resin provisional restorations. J Prosthet Dent 1987; 57:689-93.
4. Saba, S. Anatomically correct soft tissue profiles using fixed detachable provisional implant restorations. J Can Dent Assoc 1997; 63:767-70.[ Top ]