DEN203 Prosthetic Dentistry II - Record Base and Wax Rim Fabrication PDF

DEN203 Prosthetic Dentistry II Lecturer: Dr. Rana Turunç Oğuzman & Dr. Demet Ayvalıoğlu E-posta: [email protected] Record Base and Wax Rim Fabrication Altınbaş Üniversitesi Rana Turunç Oğuzman [email protected] DEN203 Protetik Diş Tedavisi 2 The Occlusion Blocks (rims)...

DEN203 Prosthetic Dentistry II Lecturer: Dr. Rana Turunç Oğuzman & Dr. Demet Ayvalıoğlu E-posta: [email protected] Record Base and Wax Rim Fabrication Altınbaş Üniversitesi Rana Turunç Oğuzman [email protected] DEN203 Protetik Diş Tedavisi 2 The Occlusion Blocks (rims) • Occlusion blocks consist of wax rims attached to well fitting denture bases. • It is used to make maxillomandibular relation records and to arrange teeth. Denture Base • Is a well adapted plate to which an occlusion rim is attached to. • Record base simulates the finished denture base. • It helps transferring accurate jaw relationships to an articulator. Requirements of a Denture Base ✓Should be 1. 2. 3. 4. 5. Stable in mouth and on the stone model Biocompatible Rigid Properly extended and accurately adapted to the cast Relieved from any undercuts Requirements of a Denture Base ✓Should be 6. 7. 8. 9. 10. Clean & smooth In proper thickness (around 2 mm thickness) Easily constructed Economic Dimensionally stable Types of Record Base • Temporary record base • Permanent record base Methods Of Construction Using Cold Cure Acrylic • Sprinkle on method • Finger adapted dough method • Flasking method • Wax confined method Record Base – An interim denture base • They are discarded and replaced by denture base material, once their role in establishing jaw relation, teeth arrangement and try in is complete. Types of temporary record base materials 1. 2. 3. 4. 5. 6. 7. Shellac base plate Reinforced shellac base plate Cold cure acrylic resin Visible light cure acrylic resin Vacuum formed vinyl and polystrene Base plate wax Swaged tin Characteristics of an Ideal Record Base ⚫ Strength and rigidity ⚫ Accuracy • The record base should not move on the cast ⚫ Smooth, rounded well polished borders ⚫ Thickness of borders and palate must resemble those of the finished dentures • Palate must be 1-2 mm thick • Thickness and contour of the denture borders are defined by the land of the master cast. The record base must not extend onto the land of the cast Materials Mostly Used for Record Bases Cold self-cure acrylic resin Light cure resin Fabrication of Record Bases and Wax Rims Instruments and Materials • Separating medium • Baseplate wax • Wax spatula • Hanau torch • Cloth polishing wheel • Large camel’s hair brush • Red handle knife • Celluloid mm rule • Bunsen burner • Autopolymerizing acrylic resin Procedures Blocking out the Master Casts -Undercuts -Frenum areas -Rugae -Irregular surfaces -Redundant tissue areas Mark areas of block out with a red pencil Flow a thin layer of wax over the outlined areas with baseplate wax Blocking out the master casts Block out frenum and other irregularities Wax should be thin enough to see through Blocked out master casts coated with Alcote tin-foil substitute Maxillary Record Base Fabrication ⚫ Sprinkle-on technique of resin addition Maxillary Record Base Fabrication ⚫ Build up labial flange by alternating polymer and monomer addition Maxillary Record Base Fabrication • Sprinkle on a thin consistent layer over the palate Maxillary Record Base Fabrication ⚫ Reinforce the ridge crest to prevent slumping Keep the surface moist with monomer to prevent porosity Keep ridge lap areas thin to facilitate tooth placement Mandibular Record Base Fabrication Manipulate the cast to prevent slumping Build up the flanges Mandibular Record Base Fabrication ⚫ Reinforce the lingual portion of the flange and ridge crest Record Base Polymerization ⚫ Process acrylic resin in Pressure Pot – 20 psi – 110 degrees water – 10 to 15 minutes In absence of a pressure pot, place casts under an over-turned rubber mixing bowl Record Base Preparation ⚫ Soak the polymerized record base and casts in hot water to soften the block-out wax Then gently remove the record bases from the master cast Record Base Preparation Gently remove all block-out wax from master cast without damaging surface Remove wax which may prevent seating of record base from tissue surface Record Base Preparation-Maxilla Areas requiring modification on unfinished record bases Record Base Preparation - Maxilla ⚫ Trim excess flash Record Base Preparation - Mandible Trim the excess acrylic resin that extends onto the land of the cast (flash) as shown here. Note: The only portion of the record base that is highly polished is the periphery. Record Base Preparation ⚫ Thin ridge lap portion of denture base Ridge Lap portion must be thin enough to accommodate the anterior teeth Record Base Contouring/Finishing Palate should be consistent 1-2mm thick to facilitate speech. Thick record bases may also precipitate gagging. Pumice the oral ( tongue) side of the palate and flanges for patient comfort Completed Record Bases Checklist ✓ Palate should be consistent 1-2 mm thick and well adapted ✓ Lingual of ridge of mandible reinforced but concave ✓ Retromolar pad area covered ✓ Thin areas labial to ridge ✓ Roughened ridge areas Completed Record Bases Checklist • No porosity or voids on tissue surface • Flanges smooth and rounded Tissue surfaces well adapted Completed Record Bases Checklist No excess flash on land area of master casts Record bases do not rock on master casts and are reasonably retentive Occlusion Rims Occlusion rims are occluding surfaces constructed on record bases or permanent denture bases to be used in recording jaw relations and for arranging teeth. 1. The position should be in the anticipated position of the artificial teeth. 2. It must be securely attached to the base 3. The occlusal surface must be smooth and flat 4. It should be contoured to support the lip and cheecks accurately. 5. All the surfaces should be smooth Wax Occlusion Rims - Purpose • Used for face bow transfer records • Aid in orientation of the incisors and the occlusal plane when properly contoured • Aid in developing contours of the lips and cheek when properly contoured • Used for measuring the vertical dimension of occlusion • Used in making tentative centric relation records • Serve as a general aid in selection of teeth Instruments and Materials Baseplate wax Wax spatula Occlusal plane former (hot plate) Technical Procedures a) Place maxillary record base on the cast. b) Heat a sheet of baseplate wax on the bunsen burner until the wax is very pliable. c) Roll the wax into long tube. d) Starting at the tuberosity, press the roll of wax against the crest of the ridge. e) Seal the wax to the record base with a hot wax spatula. If necessary, fill in the voids with additional wax. Technical Procedures f)Heat the occlusal plane former in a flame and carefully form the occlusal aspect of the rim. Catch the melted wax in a paper towel. g)Form the buccal and labial contours with the hot plate in a similar manner. If there are voids fill them with wax and repeat the process. Maxillary Wax Rim Check List Mandibular Wax Rim • The mandibular wax rim is fabricated in a similar manner, however, the rim should be centered over the crest of the ridge. Lingual contours must not impinge on the tongue space. Determine Incisor Position and Occlusal Plane Record base and wax rim is placed into position and a “Fox” occlusal plane can be used to verify the proper level and angulation of the occlusal plane. If the wax rim does not conform to the landmarks indicating the proper plane of occlusion (Camper’s plane) the was rim is altered until it does conform. Determine Incisor Position and Occlusal Plane When the wax rim is ideally contoured and mounted and the lower cast mounted on the on the articulator with a centric relation record, the plane of occlusion is readily seen. The two determinants of the occlusal plane are readily seen: The incisal edge of the central incisor The middle third of the retromolar pads bilaterally Aid in developing contour of the lips and cheeks. Wax rim is contoured with the rim former until the desired lip and cheek contours are developed Determine the Proper Vertical Dimension of Occlusion The wax rims aid the clinician in determining the proper vertical dimension of occlusion. Used to Make Centric Relation Records Serves as a General Aid in Tooth Selection The position of the corners of the mouth are marked on the wax rims and the distance between these two marks can serve as a guide for tooth selection. Maxillary Record Base and Wax Rim A wax rim properly contoured in the anterior region (arrows) aids in positioning the anterior teeth. Anterior maxillary teeth are arranged according to the labial contours developed in the patient. Videos • Record Base https://www.youtube.com/watch?v=YBrOf97nMIY • Maxillary Wax Rim https://www.youtube.com/watch?v=CrLw1JJpOv4 • Mandibular Wax Rim https://www.youtube.com/watch?v=ARo9sO8vBxk Altınbaş Üniversitesi Rana Turunç Oğuzman [email protected] DEN203 Protetik Diş Tedavisi 2