Academy of Dental Knowledge

Features of a PFM crown preparation The crown preparation should start from incisal aspect, then labial, then moving towards proximal contact area and finally to the lingual aspect in cases of anterior tooth preparation.  For posterior tooth preparation, one should start from occlusal surface, then buccal surface from  mesial to distal direction and then move to break the contact areas. After breaking contact points, start doing reduction of lingual surface from mesial towards distal direction.  The above view of the sequence of tooth reduction is of the Author, though, in the book "Fundamentals of Fixed Prosthodontics" by Herbert T. Shillingburg jr., it is given differently. The author found it better suited for himself after modifying the Shillingburg's recommended sequence to get better access. Always remember the type and final dimensions of your preparations. The recommended dimensions are given in the following tables. Always aim to reduce the tooth surface 0.1...

The pontic, \ pŏn΄tĭk \, is an artificial tooth on a fixed partial denture that replaces a missing natural tooth, restores its function, and usually restores the space previously occupied by the clinical crown. An ideal correctly designed posterior pontic should have the following features.   All surfaces should have convexity with proper finish.   The contact with buccal contiguous slop should be minimal (pinpoint)) and with pressure free (modified ridge lap).   Buccal and lingual shunting mechanisms should conform with those of the adjacent teeth.   The occlusal table should be in functional harmony with the occlusion of all of the teeth.   The overall length of the buccal surface should be equal to that of the adjacent abutment teeth or pontic.   Figure 1. Schematic presentation of various pontic designs; (a) Sanitary pontic; has no contact with the edentulous ridge, (b) ridge lap pontic; forms a large concave contact replacing the contours of a miss...