Richmond Crown- A Conventional Approach for Restoration of Badly Broken Posterior Teeth

Transcription

1 Richmond Crown- A Conventional Approach for Restoration of Badly Broken Posterior Teeth Abhinav Agarwal 1, Manish Chadha 2, D.R.V.Kumar 3, Prakash Somani 4, Preet Jain 5 Abstract: Restoration of badly broken endodontically treated teeth is a common problem in restorative dentistry. Such teeth often require additional support from the root canal by means of a post and core restoration. In cases where tooth structure is significantly lost full coverage restorations for posterior teeth are necessary to achieve proper tooth form and function. Badly broken teeth with minimal or no crown structure require addition retention and support. The Richmond crown can be a good treatment modality for restoration of such teeth. This case report shows prosthetic restoration of badly broken posterior teeth with Richmond crown. Key Words: Richmond crown, dowel and core, endodontically treated, badly broken teeth. Introduction The restoration of endodontically treated teeth has been a concern of dentists for more than 100 years. 1-6 As early as 1728, Pierre Fauchard described the use of tenons, which were metal posts screwed into the roots of teeth to retain bridges. 7 In the mid-1800s, wood replaced metal as the post material, and the pivot crown, a wooden post fitted to an artificial crown and to the canal of the root, was popular among dentists. 7 The Richmond crown was introduced in 1878 and incorporated a threaded tube in the canal with a screwretained crown. It was later modified to eliminate the threaded tube and was redesigned as a 1-piece dowel and crown. 8 During the 1930s, the custom cast post-and-core was developed to replace the one-piece post crowns. Case Report A 35 yr old female patient reported in the college with endodontically treated badly broken/decayed tooth (Fig.1) and wanted to get it restored. After treatment planning it was decided to restore the badly broken tooth with Richmond crown. Journal of Dental Peers, Vol.1, Issue 1, April

2 Fig.1: Pre-treatment Treatment Procedure First all the carious part and unsupported tooth structure was removed. It was decided to place the post in distal canal. Gutta percha was removed from distal canal with gades glidden drill, care was taken not to disturb the apical seal. Post space preparation was done with peso reamer till size 04. Tooth preparation was done as conservatively as possible. Undercut areas within the crown structure were blocked with glass ionomer cement (Fig.2). For making final impression, distal canal was coated with light body and a small piece of orthodontic wire coated with light body was placed in the canal. Later light body was injected around the prepared tooth, putty was loaded in stock tray and final impression is made (Fig.3). Fig. 3: Final Impression of post space Impression was examined for defects in recording of post space. Impression was poured with die stone and wax pattern was fabricated. Metal try in was done before ceramic build up. (Fig.4) Cementation was done with resin cement. (Fig.5, 6, 7) Fig. 2: After tooth preparation and block out Fig. 4 & 5: Metal try in & Richmond crown Discussion A single-unit post-core-crown restoration has various advantages over its multiple unit counterparts. When the post and core are two separate entities, flexion of Journal of Dental Peers, Vol.1, Issue 1, April

3 the post under functional forces stresses the post-core interface, resulting in separation of the core due to permanent deformation of post. 9 Breakdown of the core eventually results in caries or dislodgement of crown. Fig. 6 & 7: Post-treatment and Richmond crown in Occlusion The different coefficients of thermal expansion of the various components also have a deleterious effect on the bonds between the tooth-post-core-cement-crown complex. The combined effects of thermal cycling, fatigue loading, and aqueous environment test the bond between materials and cause breakdown of the materials over a period of time. Therefore, it is desirable to unify the post, core, and crown in one material for long-term stability. 10 By decreasing the number of interfaces between components, the single unit restoration helps to achieve a monobloc effect. 11 It is generally agreed that the successful treatment of a badly broken tooth with pulpal disease depends not only on good endodontic therapy, but also on good prosthetic reconstruction of the tooth. 12 Endodontically treated, molar teeth should receive cuspal coverage, but in most cases, do not require a post. Unless the destruction of coronal tooth structure is extensive, the pulp chamber and canals provide adequate retention for a core buildup. Molars must resist primarily vertical forces. In those molars that do require a post, the post should be placed in the largest, straightest canal, which is the palatal canal in the maxillary molars and a distal canal in the mandibular molars. Rarely, if ever, is more than one 13, 14 post required in a molar. In this case report Richmond crown was planned as it can be a better option instead of prefabricated posts because of major loss of tooth structure and lack of occlusal clearance for conventional PFM crown. Journal of Dental Peers, Vol.1, Issue 1, April

4 Summary and Conclusion There are situations in which Richmond crown should or should not be used, as well as features that should be considered in deciding that one is the treatment of choice for restoring a grossly decayed or badly broken tooth. Richmond crown can be used as a treatment option for the badly broken endodontically treated tooth with less occlusal clearance but should be used judiciously. References 1. Kantor ME, Pines MS. A comparative study of restorative techniques for pulpless teeth. J Prosthet Dent 1977;38: Newburg RE, Pameijer CH. Retentive properties of post and core systems. J Prosthet Dent 1976;36: Perel ML, Muroff FI. Clinical criteria for posts and cores. J Prosthet Dent 1972;28: Stern N, Hirshfeld Z. Principles of preparing endodontically treated teeth for dowel and core restorations. J Prosthet Dent 1973;30: Trabert KC, Caputo AA, Abou-Rass M. Tooth fracture- a comparison of endodontic and restorative treatments. J Endodont 1978;4: Sorensen JA, Martinoff JT. Clinically significant factors in dowel design. J Prosthet Dent 1984;52: Smith CT, Schuman NJ, Wasson W. Biomechanical criteria for evaluating prefabricated post- and -core systems: a guide for the restorative dentist. Quintessence Int.1998;29: Smith CT, Schuman N. Prefabricated post-and-core systems: an overview. Compend Contin Educ Dent. 1998;19: Libman WJ, Nicholls JI. Load fatigue of teeth restored with cast posts and core and complete crowns. Int J Prosthodont 1995;8: Ahn SG, Sorensen JA. Comparison of mechanical properties of various post and core materials. J Korean Acad Prosthodon 2003;41: Vinothkumar TS, Kandaswamy D, Chanana P. CAD/CAM fabricated single-unit all-ceramic post-corecrown restoration. J Conserv Dent 2011;14: Goodacre CJ, Spolnik KJ. The Prosthodontic management of Journal of Dental Peers, Vol.1, Issue 1, April

5 endodontically treated teeth: A literature review: Part I: Success and failure data, treatment concepts. J Prosthodont. 1994;3: Richard S. Schwartz, James W. Robbins.Post Placement and Restoration of Endodontically Treated Teeth: A Literature Review. journal of endodontics Vol. 30, No. 5, May Franklin S. Weine endodontic therapy. (6 th edition) Correspondence: 1 Dr. Abhinav Agarwal, Senior Lecturer, Pacific Dental College and Hospital, Debari, Udaipur Contact Info: drabhi_17@yahoo.co.in, Phone no: Dr.Manish Chadha, Senior Lecturer, 3 Dr. D.R.V. Kumar, Reader, 4 Dr. Prakash Somani, Senior Lecturer, 5 Dr. Preet Jain, Senior Lecturer, Pacific Dental College and Hospital, Debari, Udaipur Journal of Dental Peers, Vol.1, Issue 1, April