An endodontic crown or endocrown is a single prostheses fabricated from reinforced ceramics, indicated for endodontically treated molar teeth that have significant loss of coronal structure.[1] Endocrowns are formed from a monoblock containing the coronal portion invaded in the apical projection that fills the pulp chamber space, and possibly the root canal entrances; they have the advantage of removing lower amounts of sound tissue compared to other techniques, and with much lower chair time needed. They are luted to the tooth structure by an adhesive material. The ceramic can be milled using computer-aided techniques[2] or molded under pressure.[3] Endocrowns can be an alternative to conventional crown restorations.
History and classical approach
editIt was Bindl and Mörmann[2] who named this restorative procedure "endocrown" in 1999, defining it as a total porcelain crown fixed to a depulped posterior tooth, which is anchored to the internal portion of the pulp chamber and to the cavity margins, thus obtaining macromechanical retention (provided by the pulpal walls) for restoring endodontically treated teeth.
The classical approach is to build up the tooth with a post and core, which have physical properties close to those of natural dentin, utilizing adhesive procedures and placement of full-coverage crowns with a sufficient ferrule, but it was found that excessive amount of teeth removal may cause fracture to the teeth.[4] The literature suggests that endocrowns may perform similarly or better than the conventional treatments using intraradicular posts, direct composite resin or inlay/onlay restorations.[5]
Indications and contraindications
editEndocrowns are especially indicated in cases of molar teeth with short, or fragile roots. They may also be used in situations of excessive loss of coronal dental tissue. Reinforced, acid-etchable dental ceramics have been the materials of choice for the fabrication of endocrowns because they guarantee the mechanical strength needed to withstand the forces exerted on the tooth, as well as the bond strength of the restoration to the cavity walls.
Using endocrowns for premolars is contraindicated as the tooth is more likely to be subjected to lateral forces during mastication than molars because of the steep cuspal incline. Therefore, premolars are prone to fracture after restoration.[6]
Clinical trials and research
editA systemic review and meta-analysis showed a success rate of endocrowns varying from 94 to 100%.[5] Analysis in posterior and anterior teeth demonstrated that endocrowns had higher fracture strength than conventional treatments. Another study showed that an endodontic crown preparation appeared acceptable for molar crowns but inadequate for premolar crowns.[1]
The longest duration of survival is for molar endocrowns is a five-year clinical follow-up period, with success rate of 87.1%. Root fracture is a very possible finding in premolar and anterior teeth.[7][8]
References
edit- ^ a b Biacchi, Gislaine Rosa; Mello, Beatriz; Basting, Roberta Tarkany (2013). "The Endocrown: An Alternative Approach for Restoring Extensively Damaged Molars". Journal of Esthetic and Restorative Dentistry. 25 (6): 383–90. doi:10.1111/jerd.12065. PMID 24148141.
- ^ a b Bindl, A; Mörmann, W. H. (1999). "Clinical evaluation of adhesively placed Cerec endo-crowns after 2 years--preliminary results". The Journal of Adhesive Dentistry. 1 (3): 255–65. PMID 11725673.
- ^ Deesri, W; Kunzelmann, KH; Ilie, N; Hickel, R (June 26, 2003). Fracture Strength and Weibull Evaluation of the Cerec® Endocrowns and Post-and-core-supported Conventional Cerec® Crowns. 81st General Session of the International Association for Dental Research. Goteborg, Sweden. Archived from the original on November 26, 2005. Retrieved June 11, 2017.
- ^ Veselinovic, Valentina; Todorovic, Aleksandar; Lisjak, Dejan; Lazic, Vojkan (2008). "Restoring endodontically treated teeth with all-ceramic endo-crowns: Case report". Stomatoloski glasnik Srbije. 55 (1): 54–64. doi:10.2298/SGS0801054V.
- ^ a b Sedrez-Porto, José Augusto; Rosa, Wellington Luiz de Oliveira da; Da Silva, Adriana Fernandes; Münchow, Eliseu Aldrighi; Pereira-Cenci, Tatiana (2016). "Endocrown restorations: A systematic review and meta-analysis". Journal of Dentistry. 52: 8–14. doi:10.1016/j.jdent.2016.07.005. PMID 27421989.
- ^ Salis, Sergio G.; Hood, James A. A.; Stokes, Alastair N. S.; Kirk, Ewen E. J. (1987). "Patterns of indirect fracture in intact and restored human premolar teeth". Dental Traumatology. 3 (1): 10–4. doi:10.1111/j.1600-9657.1987.tb00165.x. PMID 3471511.
- ^ Aquilino, Steven A.; Caplan, Daniel J. (2002). "Relationship between crown placement and the survival of endodontically treated teeth". The Journal of Prosthetic Dentistry. 87 (3): 256–63. doi:10.1067/mpr.2002.122014. PMID 11941351.
- ^ Cheung, William (2005). "A review of the management of endodontically treated teeth". The Journal of the American Dental Association. 136 (5): 611–9. doi:10.14219/jada.archive.2005.0232. PMID 15966648.