Custom Trays Individualized trays for making final impressions

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 2 nd premolars / 1 st molars

Finish l Do not polish - adhesion l 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 Bunsen Burner or Butane Torch for Initial Softening of stick Hanau Torch for resoftening of borders already on tray

Tray Wax Spacer l Remains in place during border molding procedures

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

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

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

Assessing Peripheral Role l Proper thickness l No overlap

Mandible l More difficult l Changing position of the floor of the mouth

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

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

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

Buccal Extension l Look for fold in vestibule

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

Posterior Lingual Areas l Denture should not lift with normal tongue movements

Border Molding Video