Lecture 14: Waxes

Question 1

what are dental waxes?

Answer 1

diverse group of organic thermoplastic compounds that are malleable solids near ambient temperatures

Question 2

what are the types of waxes?

Answer 2

• natural which contains: animal, plant and mineral based
• synthetic

Question 3

what is a melting range for wax?

Answer 3

waxes don’t melt at the same single temperature due to variation in composition

Question 4

what is flow? and when should it be the greatest? least?

Answer 4

• change in shape under applied forces results from movement of molecules over each other
• time of preparing wax and should have no flow at room temp

Question 5

flow depends on ?

Answer 5

applied force
time
temperature

Question 6

dental waxes have the highest coefficients of _______ of any dental material

Answer 6

thermal expansion

Question 7

what are some mechanical properties of waxes?

Answer 7

• low compressive strength
• low modulus of elasticity (not stiff, flexible)
• depends on wax type

Question 8

what is residual stress? and when is stress released?

Answer 8

• stress remaining in the wax as a result of manipulation during heating, cooling, bending, carving, or other manipulation
• as the temperature of the wax increases

Question 9

what are pattern waxes? and what are some examples?

Answer 9

• used to create model of dental restoration (crown or partial)
• inlay wax, casting wax, base plate wax

Question 10

what are processing waxes? and what are some examples?

Answer 10

• used in roles of the fabrication of models and impressions
• boxing, beading, utility and sticky wax

Question 11

what are inlay waxes used for?

Answer 11

generally used to fabricate wax patterns for crowns, inlays or bridges

Question 12

what is casting (RPD) wax used for?

Answer 12

used to form wax pattern of metallic framework of removable partial dentures
- not brittle, copy accurately, pliable

Question 13

what are base plate waxes used for?

Answer 13

baseplates are used to build the contours of a denture and hold the position of the denture teeth before the denture is processed in acrylic

Question 14

what are the three types of base plate wax and what are they used for?

Answer 14

type I (soft): used for contouring dentures and veneers
type II (medium): used for patterns that will be placed into the mouth in a temperate climate
type III (hard): used for mouth use in tropical climates

Question 15

what are boxing waxes used for and what are are they made of?

Answer 15

primarily used for taking and puring impressions
bees wax, paraffin, soft waxes

Question 16

what are utility waxes used for and what are they made of?

Answer 16

alter the stock tray extensions and rim the tray to prevent irritation/high adjustment
bee wax, petrolatum, soft waxes

Question 17

what is sticky wax and what are are they made of?

Answer 17

• hard, brittle, sticky material that will adhere tenaciosuly yo hard stone or other dental materials
  yellow bees wax, rosin, resin

Question 18

what is bite-registration wax and what is it made of?

Answer 18

• used for acurate articulation of certain models of opposing arches
• paraffin, ceresin, bees wax, trace of Al or Cu

Question 19

what are the methods for softening wax?

Answer 19

• bunsen burner
• water bath
• infrared lamp
• wax annealer