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MAJMAAH UNIVERSITY, COLLEGE OF DENTISTRY, ZULFI, Assalam-alekum SELECTION AND ARRANGEMENT OF TEETH FOR RPD DR. TAJammul AHMED a.tajammul@gmail.com MAJMAAH UNIVERSITY, COLLEGE OF DENTISTRY, ZULFI,

SELECTION OF DENTURE TEETH While selecting the replacement teeth, the clinician must carefully consider the esthetic and functional requirements of the patient, the structural requirements of the RPD and the materials to be used in prosthesis construction. Choice of materials Acrylic resin denture teeth Porcelain denture teeth, In more recent years Glass ceramics and Composite materials.

ACRYLIC RESIN DENTURE TEETH ADVANTAGES DISADVANTAGES Resilient, Wear-resistant, Natural-sounding in function, Aesthetic Easy to adjust, can be recontoured. Polished with little effort low abrasion resistance Proper function of the occlusal relationships must be checked more frequently when acrylic resin teeth are used Because of their greater ease of placement, acceptable esthetics, and decreased danger of fracture, acrylic resin teeth are commonly used in RPD service than the porcelain teeth.

PORCELAIN DENTURE TEETH ADVANTAGES High abrasion resistance Exhibit minimal wear Highly Aesthetic match the porcelains used for fixed restorations DISADVANTAGES Sound unnatural to thepatient Brittle Chip or crack, Difficult to adjust, recontour, and polish

Mold & Shade Selection for anterior teeth Guide is always provided by the manufacturer Guide should be moistened before using. Selection should be made under natural light where possible. Match the shade to the remaining natural teeth. Obtain the shade as quickly as possible

Mold & Shade Selection for anterior teeth Mold Selection: Selected as close to the remaining natural teeth as possible and then modified to match by selective grinding. For all anterior missing teeth - Use Complete Denture guidelines Each mold exhibits a different shape and size and also different surface characteristics

Tooth Size Selection Shape Selection High Lip Line - indication of inciso-gingival length Pre-extraction cast or photographs can be useful Shape Selection Tooth shape correspond to facial shape Trubyte system good starting point

Guidelines for Setting Anterior Teeth 1. Replace the acrylic resin record base attached to the framework with the base-plate wax base. 2. Set the Central Incisor first if the teeth are missing across the midline to reestablish the midline. 3. If required – reshape the ridge lap portion of the artificial tooth without shortening the clinical crown length substantially.

Guidelines for Setting Anterior Teeth 4. Place the teeth as nearly as possible where the original natural tooth was located. 5. Proximal surface of the artificial tooth may need to be recontoured for better adaptation to the adjacent natural tooth, without loosing its morphology. 6. The denture base flanges should be carefully contoured & smoothed. Remove the excess wax from the teeth and the framework.

Problem: Narrow Space Mesio-distally. Some Problems Encountered while Setting Anterior Teeth Problem: Narrow Space Mesio-distally. Cause: Tilting or drifting of the adjacent teeth into the space. Solution: 1. Avoid this situation by immediate replacement dentures. 2. Regain the original width by reshaping the proximal surfaces of adjacent teeth. 3. Overlap arrangement of the artificial teeth of proper size. 4. Use narrower teeth than the adjacent teeth - with poor esthetics.

Problem: Excessive Loss of Residual Ridge. Some Problems Encountered while Setting Anterior Teeth Problem: Excessive Loss of Residual Ridge. Cause: Poor surgery at the time of tooth extractions or enhanced ridge resorption. Solution: Place the artificial teeth in their natural position. Acrylic resin flange should be built to the desired thick-ness to support the artificial teeth and to restore symmetry and contour of the lips. Problem: Bulbous, too full, large edentulous ridge. Cause: Naturally bulbous ridge, poor surgery, or minimal resorption of the alveolar process post extraction. Solution: Artificial tooth is butted directly over the ridge.No labial flange is added to avoid plumping the lip andaffect esthetics.

Mold Selection for the Posterior teeth The tooth size, or mold, is generally dictated by the size of the edentulous space, For an RPD replacing all posterior teeth, complete denture guidelines should be applied, e.g., distance from the distal surface of the natural Canine to the upward incline of the ramus or mesial aspect of maxillary tuberosity. Occluso-gingival height of the denture tooth should match with the adjacent natural tooth for good esthetics. Re-contouring the ridge lap portion of the tooth can be done

Posterior Denture Teeth 1. should fit into the available edentulous space. 2. should be harmonious in composition, size, and occlusal anatomy with the opposing teeth. Adjacent teeth should guide the artificial teeth in their correct bucco-lingual position. 3. the type or number of artificial teeth may differ from the type and number of missing teeth – if drifting of abutment teeth has occurred.

Guidelines for Setting Posterior Teeth As a rule – achieving classic pattern of intercuspation of opposing teeth should be attempted. To position the denture tooth adjacent to the abutment having a clasp or a Minor Connector, trimming of the proximal surface and the ridge lap portion of tooth is done carefully. The remaining teeth should then be positioned in maximum intercuspation. Some occlusal adjustment or leaving small spacing between two denture teeth may be necessary.

Guidelines for Setting Posterior Teeth For the mandibular posterior teeth, central groove should be placed over the crest of the ridge. After establishing good centric occlusal contacts, lateral and protrusive contacts of the posterior teeth during function should also be developed by moving the semi-adjustable articulator in use. For an RPD opposing a CD, bilateral balanced occlusion in centric and all eccentric positions is desired.

Waxing-up RPD for Wax Try-in The denture flanges should be contoured and smoothed to provide a pleasing appearance. The distal extension saddle areas should be maximally covered for better soft tissue support. The gingival contouring should harmonize with the adjacent natural teeth and should be self cleansing.

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