Lecture 11

Question 1

what is the organic component of dental waxes?

Answer 1

hydrocarbon (paraffin) and a high molecular weight ester

Question 2

the hardness, melting range, and flow depend on the amounts of various waxes and the mol. structure of the organic ‘cules in the mixtures

Answer 2

ye

Question 3

what are important properties of wax/

Answer 3

• melting range
• excess residue
• flow
• thermal expansion–heating a cooling cycles lead to dimensional distortion
• residual stress –stress remaining in the wax as a result of manip. during heating, cooling, bending, carving, etc –>can be avoided by carving when wax is close to melting temp and with warm instruments

Question 4

what are the types of waxes?

Answer 4

1. pattern waxes

2. processing waxes

Question 5

describe pattern waxes

Answer 5

used to fabricate restoration using lost wax technique

include:
inlay wax–>fabricated for crowns, inlays, or bridges

casting wax–>form wax patterns of metalic framework of removable prosthos

baseplate wax–>used for baseplate of denture; build the contours of the denture to hold the position of the denture teeth

resins –> higher strength, lower flow, and burnout without residue (important!!!)

Question 6

what are processing waxes?

Answer 6

used for auxillary roles in the fabrication of models, impressions, and in soldering

• boxing and utility wax–> soft, pliable waxes for taking impressions
• sticky wax –> hard and brittle at room temp but becomes sticky when heated, and sticks to dry stone or other dental materials; can assemble metallic or resin pieces, or as a sealant
• corrective impression wax: used as a veneer over an original impression to register the details of the soft tissue in the functional state
• bite registration wax–>accurate artic. of certain models of opposing arches