Restoration of Endodontically Treated Teeth

Dr. Nawfal Zakarea Assistant professor MBCHB.1990 MSc.1994, PhD.2015 In Conservative Dentistry

Endodontically treated teeth often exhibit minimal tooth structure after treatment, these teeth should be restored in a manner that will provide: coronal seal, adequate retention and a strength to ensure optimal success. Endodontic success depends not only on the quality of the root canal treatment, but also on timely coronal restoration of the compromised tooth.

Treatment Goals Maintain coronal seal of the root canal treatment Protect and preserve the remaining tooth structure Provide a supportive and retention foundation for the placement of definitive restoration Restore the function and esthetics

Factors Affecting the Planning of the Restoration Amount of remaining sound tooth structure Occlusal function Opposing dentition Position of the tooth in the arch Length, width and curvature of the roots

Classification Endodontically treated teeth can be classified according to the remaining tooth structure into: Classification Description Class I 4 walls Class II 3 walls Class III 2 walls Class IV 1 wall Class V No wall

CL II CLV

Anterior Teeth With only a conservative access opening, anterior teeth can be restored with a resin restoration. Placement of a post is not necessary when a complete coverage restoration is not indicated.

Anterior Teeth

Anterior Teeth Post installation may inhibit attempts to bleach a discolored endodontically treated tooth. Moreover, a post does not strengthen the root. Large interproximal restorations, incisal edge fractures, or esthetic concerns may necessitate the placement of a post and core, as well as full coronal coverage.

Anterior Teeth In cases of extensive loss of external tooth structure, a post is usually required for anterior teeth, due to the predominantly shear forces present and the narrow tooth dimensions. Extra-coronal crown preparation combined with endodontic access preparation significantly weakens the cervical area of anterior teeth.

Anterior Teeth

Anterior Teeth

Posterior Teeth Endodontically treated posterior teeth are subject to greater loading than anterior teeth, because of: Their position closer to the insertion of the masticatory muscles. This, combined with their morphologic characteristics, makes them more susceptible to fracture. Hence, Full-coverage crowns are indicated to prevent fracture when occlusal forces act to fratured the cusp tips.

Posterior Teeth If significant tooth structure has been retained, a crown may be all the coverage required. If minimal structure remains, a post may be necessary to help retain a foundation before crown placement. In ultra conservative access cavity with minimal caries the tooth may not need crown, just composite restoration.

Posterior Teeth

Components of Final Restoration Post Core Crown

Posts Role of Post: The primary purpose for a post is to retain a core that can be used to support the final restoration. Posts do not reinforce endodontically treated teeth (except in case of fiber post), and a post is not necessary when substantial tooth structure is present after a tooth has been prepared.

Indications of Posts Post placement is indicated if both of the following clinical conditions exist: The remaining coronal tooth structure is inadequate for the retention of a restoration. When there is sufficient root length to accommodate the post while maintaining an adequate apical seal.

Factors to be Considered Post length Post diameter Post design (end design of the post) Selection of root for post: A- The largest B- Straight or with minimal curvature

Post Length Post length is unique and individualized for each case. The clinician should have a thorough knowledge of root morphology before placing a post. The post should more than the incisocervical or occlusocervical dimension of the crown. The post should end halfway between the crestal bone and the root apex. The longer the post, the greater the retention.

Post Length A guideline of one half to three quarters of the root length is often followed but may not be reasonable for extremely long, short, narrow, or curved roots. At a minimum, the post length should be equal to or greater than the crown length of the restored tooth. At least 4 to 5 mm of gutta-percha should be left in the apical portion of the canal to ensure an adequate seal. If this guideline cannot be followed and the post is shorter than the crown, extraction should be considered.