The objective of a post-and-core buildup is primarily to replace missing coronal tooth structure sufficiently to provide adequate retention and resistance for the crown that will eventually restore the function and the aesthetics of the tooth in question. The use of posts is still an area of great debate within dentistry. This debate ranges from dentists who only do cast posts, to dentists who use any of a variety of prefabricated systems, to clinicians who do not believe that posts are clinically effective. Within the literature, there are wide ranging studies that could be used to support any of the above beliefs. In the end, clinical experience, common sense, and evidence-based decisions should be the practitioner’s guide as to whether to use a post or not.
n the last decade, the use of prefabricated fiber posts has gained a lot of popularity with dentists. These new systems have demonstrated a modulus of elasticity that closely matches dentin, a reduction of stresses concentrated within the root canal, and reduced incidence of fracture.
The purpose of a post is to retain a core that is needed because of extensive loss of coronal tooth structure; a post is not intended to provide any increase in the strength of the tooth. A post is the anchor to which the core gains additional retention. Fiber posts are able to provide additional retention because they are bonded into place. A fiber post is adhesively bonded into place using a bonding agent in combination with a dual cure resin cement. This combination allows for the resin cement to bond to the dentin of the tooth and the resin reinforced fibers of the posts. The post is then adhesively retained to the core when a composite resin build-up material is used. The synergistic nature of the use of these materials has the potential to create the strongest possible replacement of missing tooth structure.
able. Universal Principles to Consider When Placing Posts
Preserve as much healthy tooth structure as possible
Avoid contamination of the root canal system
Restore the tooth as soon as possible after completion of the root canal
Use posts only when necessary to retain a core buildup
The post preparation should leave a minimum of 4 mm of gutta-percha at the apical end
The minimum length of the post below the crest of bone should be equal to the height of the tooth above the crest of bone.