Custom Trays Individualized trays for making final impressions Made on a diagnostic cast

Purpose of a Custom Tray Improve retention (border molded) Minimize: Impression material distortion Uniform thickness Rigid tray

Purpose of a Custom Tray Minimize: Tissue distortion Less viscous material Accurately adapted tray Costs less impression material used

Extension 3-4 mm short of the peripheral role Diagnostic casts often overextended (irreversible hydrocolloid)

Block-Out Undercuts Baseplate wax Prevent tray from locking onto cast Lubricate cast (Petroleum jelly or Alcote)

Wax Spacer Minimizes hydraulic pressures Do not place relief over blockout Already relief in those areas Provides room for impression material

Auxiliary Handles Mandible For stabilization Orient the tongue Area of 2nd premolars / 1st molars

Finish Do not polish - adhesion No holes until border molded

Custom Tray Videos Outlines for Custom Trays Custom trays

Border Molding Performed with Thermoplastic modeling compound Waxes Impression materials

Heat Source for Compound Hanau Torch for resoftening of borders already on tray Bunsen Burner or Butane Torch for Initial Softening of stick

Tray Wax Spacer Remains in place during border molding procedures

Wax Spacer Keep out of hot water bath to prevent melting Difficult to replace tray intraorally in the same position Results in uneven border molding

Tempering Compound Temper in a water bath (135-140°F) for several seconds Prevent burning Hot water bath will keep compound soft for an extended period

After Removal Chill in cold water Trim excess over wax spacer or external material that is thicker than 4-5 mm Clean debris from tray

Assessing Peripheral Role Proper thickness No overlap

Mandible More difficult Changing position of the floor of the mouth

Posterior Buccal Areas Pull cheek upward while holding tray in place Have patient suck cheeks inward while holding tray in place

Retromolar Pad Should be covered (at least partially) to provide a seal and comfort to the patient

External Oblique Ridge Don’t extend past Palpate cheek at angle of the mandible Smooth transition between mandible & border - not palpable

Buccal Extension Look for fold in vestibule

Retromylohyoid Space Distolingual border can extend Straight down from the retromolar pads Anteriorly to varying degrees Almost never angles posteriorly from retromolar pads

Posterior Lingual Areas Denture should not lift with normal tongue movements

Border Molding Video