Prosthodontic Occlusion Lecture 1 PDF

Prosthodontic Occlusion Lecture 1 Dental impressions Working casts & Dies  Working (or master) cast is the positive reproduction of the prepared teeth, ridge areas, and other parts of the dental arch. Die is the positive reproduction of the prepared tooth and consis...

Prosthodontic Occlusion Lecture 1 Dental impressions Working casts & Dies  Working (or master) cast is the positive reproduction of the prepared teeth, ridge areas, and other parts of the dental arch. Die is the positive reproduction of the prepared tooth and consists of a suitable hard substance of sufficient accuracy Impression pouring A. Dowel Pin Technique Pre-pour Technique Technique Sectioning and die preparation SECTIONING AND DIE PREPARATION  Die trimming: Remove most of excess stone with Arbor band. Use a pear-shaped acrylic bur to trim the die apical to the finish line of the preparation. Then fine trimming and smoothening with scalpel or cleoid-discoid carver. Advantages of die trimming: Accentuate the finish line Resembling the normal contour of the natural root for proper cervical contouring of the wax pattern. Produce smooth area gingival to the finish line Die Preparation: 1. Apply die hardener Cover die beyond finish lines Allow to set for 5 minutes 2. Apply die spacer 40-micron thickness allows space for cement 2-3 coats placed Spacer 1 mm from finish line Remove excess with die setting retardant Pindex system: Tooth Preparation Evaluation Allceramic preparation Metal ceramic preparation A. ASSESSMENT OF OCCLUSAL CLEARANCE AND FUNCTIONAL CUSP BEVEL Depth cuts: Burnisher: Wax: Evaluation of Functional Cusp Bevel Location Amount Slope B. ASSESSMENT OF THE PROXIMAL CONTACT.  Opened proximal contacts and no injury to adjacent teeth. C. ASSESSMENT OF AXIAL REDUCTION Evaluating the amount of reduction: Diamond Stone Diameter Caliber Evaluating the amount of reduction: Depth Cuts Evaluating the amount of reduction: Temporary Crown thickness Evaluating the amount of reduction: Index Vertical Horizontal  Evaluating taper/wall angulation: Evaluate the convergence between the opposing walls from the correct direction. Check the taper of M & D walls by looking from the B aspect and check the taper of the B & L walls by looking from the M aspect D. ASSESSMENT OF FINISH LINE. Finish line (6 points)  Type: Chamfer/Deep Chamfer No enamel Lip  Thickness: 0.5 mm/ 1 mm/ 1.5 mm  Position: 0.5 mm above the gingival contour (Supra-gingival)  Contour: Following contour of gingiva  Continuous between walls  Smooth, no irregularities and well-defined. Finish line