Lecture 8

Question 1

E. max CAD (lithium disillicate)

How does it come?

Answer 1

In a BLUE STATE (composed primarily of lithium metasilicate, which is easier to mill and results in lower bur wear) . AFTER milling process is completed, material is heat treated and glazed in one step, forming the final Lithium disilicate prepared for cad/cam use

Question 2

All Ceramics Classifications (3)

Answer 2

Glass-matrix ceramics

pollycrystalline ceramics

Resin matrix ceramics

Question 3

Examples of glass-matrix ceramics

Answer 3

feldspathic

synthetic (leucite-based, lithium disilicate (e-max), fluroapitate)

Glass-infiltrated (alumina, alumina and magnesium, alumina and zirconia)

Question 4

Examples of pollycrystalline ceramics

Answer 4

alumina

stabilized zirconia

zirconia-toughened alumina

alumimna-toughened zirconia

Question 5

Examples of resin-matrix ceramics

Answer 5

zirconia-silica ceramic in a resin interpenetrating phase

Question 6

Examples of Feldspathic

Answer 6

IPS empress Esthetic, IPS empress CAD, IPS classic, Ivoclar Vivadent, Vita VMK 68

Question 7

What is feldspathic made out of

Answer 7

Clay/Kaolin (Hydrated Aluminasilicate)

Quartz (Silica)

Feldspar (Potassium and sodium aluminasilicates)

Question 8

Synthetic composed of?

Answer 8

silicon dioxide, potassium oxide, sodium oxide, and aluminum oxide

They can be combined with apatite crystals or LEUCITE

Question 9

What does leucite do?

Answer 9

reinforces the glass by defecting and arresting the propagation of cracks.

Makes ceramics stronger and helps prevent cracks.

Leucite glass ceramics present excellent esthetics due to high and adjustable translucency.

Question 10

Polycrystalline ceramics

Aluminious oxide
stabilized ZIRCONIA

zirconia-toughned alumina (ZTA)

Alumina toughned zirconia (ZTA and ATZ)

Answer 10

fine grain crystalline structure, provides strength and fracture toughness

LIMITED translucency due to the absence of glass phase

difficult to etch with hydrofluoric acid

Question 11

Resin-Matrix Ceramics

Lava Ultimate
Enamic Vita

Answer 11

organic matrix highly filled with ceramic particles

Question 12

General rules

Answer 12

Greater crystalline content results in higher flexural strength but also can decrease translucency

As a general rule, relationship between strength and esthetics is INVERSELY proportional

Question 13

CAD/CAM Materials:

Vita Mark II (Feldspar Ceramic)

Answer 13

Vita Mark II presented with more translucency than IPS e.max CAD at both 0.5 and 1.0 mm

This is are most esthetic porcelain

Flexural strength 125 +/- 10 mpa

Question 14

CAD/CAM Materials:

Vita Enamic

Answer 14

Flexural strength 170 +/- 10 mpa

VITA Enamic has a LOWER translucency than other resin ceramic hybrid materials

Question 15

CAD/CAM Materials

IPS e.max: lithium disilicate glass ceramic

Answer 15

Flexural strength 360 +/- 40 mpa

Question 16

CAD/CAM Prothesis

Answer 16

milling process does not create a smooth surface ready for cementation.

The ceramic material must be contoured and finished post-milling to make it ready for delivery.

Wash the crown after the milling

Question 17

Polishing

Answer 17

maximize flexural strength

Minimizes the risk of chipping or fracture

Minimizes abrasive wear of opposing teeth and restorations

Maximizes biocampatibility by limiting adherence of bacteria to the surface of the restorations

Question 18

Do you still need to polish before you glaze?

Answer 18

100%. all polished surfaces were significantly smoother than the positive control (glazed empressCAD samples)

Question 19

Polishing

Exa cerapol wheel

Blue wheels and points
Pink wheels and points
Grey wheels and points

Answer 19

gross adjustments and pre-polishing (exa cerapol wheel)

Blue for adjusting porcelain

Pink for pre-polish

High shine with grey wheels

Question 20

any material used to attach or cement indirect restorations to prepared teeth

Answer 20

Luting agents

Question 21

This traditional cement acts by filling a space and binding adjacent surfaces

Answer 21

Non-adhesive

Question 22

chemically interacts with the surface of the tooth and or restoration. Adherence or bonding to the surface is involved

Answer 22

adhesive

Question 23

process of multilink

Answer 23

etch everything except zirconia

try-in patients mouth

clean with ivoclean

apply monobond to intaglio of restoration for 1 min

Question 24

Resin modified glass ionomer cements

advantages and dis

Answer 24

chemical bond
flouride release
good compressive strength

disadvantages: expansion, soluble in oral fluids

Question 25

filled resin cements

advantages and dis

Answer 25

adv:
bond to tooth
high compressive strength
essentially insoluble

dis:
technique sensitive
very expensive
sensitivity to eugenol
inhibition layer

Question 26

How long to etch?

Answer 26

E.Max (20 sec w/ 5% HF)

Celtra Duo (5-9% HF30 sec)

Enamic (5% HF 60 sec or 30 sec with 9.6%)

Feldspathic (5% HF for 60 sec)