Presentation on theme: "Record Blocks An aid to allow the transfer of occlusal relationship and other prescriptive information to the laboratory."— Presentation transcript:
Record Blocks An aid to allow the transfer of occlusal relationship and other prescriptive information to the laboratory.
Learning Outcomes Discuss the principles and uses of record blocks Construct various types of record block. Utilise the different materials used in their construction and observe their working properties Demonstrate safe working practice in the laboratory
Sufficient teeth to occlude models
Sufficient teeth to occlude and sufficient anterior information ?
May occlude but is it stable for articulation ? Anterior information required here
No teeth to occlude !
Functions of Record Blocks Where insufficient natural teeth are present to define the occlusion, blocks used to aid articulation of models Where anterior teeth are missing, blocks used to provide information :- – Incisal level – Labial fullness – centreline
Wax wafers and Edentulous record Blocks
Ideal Properties of Record Block Comprises two parts – Base and Rim – Base firm and strong well adapted correct extensions / dimensions muscle trimmed
Ideal Properties of Record Block cont. Rim Softer and easy to adjust at chairside Sit directly over the alveolar ridge crest on the lower Sit forward of the alveolar ridge crest on the upper and between the alveolar ridge crest and the sulcus in the posterior region
Construction of Record Block. Base plate materials should be – Firm and strong – Easy to manipulate – Stable at mouth temperature Base plate materials – – Wax – Shellac – Vacuum formed – Acrylic or composite light cure – Metal alloy ie. cobalt chromium
Construction of record Blocks cont. Rim should be easily adjusted – Stable at mouth temperature – Non-toxic Rim materials – Wax – Plaster / pumice – Composition
Construction of record Block cont. Dentate Rim height 1 to 2 mm higher than standing teeth. Dentate Rim width same as standing teeth Edentulous Rim 9mm anteriorly and 6 mm posteriorly Edentulous rim width 4mm anteriorly and 6mm posteriorly