-Buildup is important from the microbiologic aspect as soon as possible after completion of the endodontic treatment in order to obtain coronal seal (coronal microleakage has been linked to endodontic failure)
– Pulpless teeth have weak buccal and lingual walls, lacking adequate support.
-when two or more of the walls are missing (before or after tooth preparation) retention of the core is necessary.
– A thorough examination should be made only after initial coronal preparation to reach the final decision regarding the nature of the buildup and weather a retention is needed or not.
-If following preparation: the thickness of the wall is 1 mm or less, this is tantamount to a missing wall, and it should be removed.
– Retention means: pulp chamber walls, coronal-radicular space, undercuts, parapulpar pin and posts.
-Tooth strength following endodontic treatment is in direct proportion to the remaining dentin and is not augmented by the post.
– 2-3 mm of prepared dentin beyond the finish line provide the essential ferrule effect (minimum of 1.5 mm according to Lenchner)
– violation of the biologic width will result in irreversible damage to the attachment apparatus (crown lengthening or forced eruption).
-Post length is determined according to root length but should not exceed ¾ of the root Length or violate the apical 4-5 mm of the GP.
variety of systems should be used to strike a balance between the extent of retention and the resistance to tooth fracture.
The clinician’s decision to fabricate an immediate buildup for molars and premolars is based on the bulk of remaining tooth structure after the initial preparation, the nature of the existing pulp chamber, and the ability to obtain marginal seal.
Case #1: custom-made provisional acrylic resin crown for an immediate amalgam restoration