Anterior full coverage crowns

Question 1

Indications

Answer 1

 Aesthetics
 Broken down anterior teeth
 Toothwear
 Trauma
 Atypical shape and hypoplastic conditions
 Milled crowns and attachments for dentures
-milled crowns incorporate partial denture design (rests seats and guiding plane built in)
 Retainers for cantilever bridgework
 To alter occlusion

Question 2

Contraindications

Answer 2

Other more conservative restorative
options are viable
 Poor OH
 Very broken-down tooth with caries
extending subgingivally
 Periodontal condition- not enough
bone support

Question 3

Types of anterior crowns

Answer 3

Metal ceramic
All porcelain
 Porcelain jacket crown
 Dentine bonded crown
 High strength porcelain
 CAD CAM
Other types

Question 4

Metal-ceramic crowns

Answer 4

 Most popular porcelain crowns
 Metal core and ceramic veneer
 Heavy labial prep (1.5mm)
 Lighter palatal prep (0.7mm)
 Less aesthetic due to metal
substructure
 Option for metal backings
 Good for bruxism cases

Question 5

All porcelain crown typesn

Answer 5

 Porcelain jacket crown
 Dentine bonded crown
 High strength porcelain
 CAD CAM

Question 6

All porcelain: Dentine bonded crowns

Answer 6

 Use thin layer of glass ceramics (Feldspathic, Leucite reinforced, Lithium disilicate) relying on bonding to underlying tooth structure for strength
 Light chamfer margin conservative preparation (0.7mm)
 Ideal for minimally restored teeth requiring crowns for aesthetic reasons

Question 7

All porcelain: Pressed ceramics

Answer 7

 A strong core or full contour crown is produced by pressing
ceramic material at high temperature on a die
 Empress I, II a popular example of this type

Question 8

All porcelain: Castable ceramics

Answer 8

 Dicor system
 Wax pattern of crown was made, invested in a special
investment and casted in a glass-ceramic material
 The casting was then placed in a ceramic oven and left for several hours
 Crystalization process was taking place giving a stronger core
 The core is veneered with feldspathic porcelain to achieve good aesthetics

Question 9

All porcelain crowns: Glass-infiltrated high strength ceramic core systems

Answer 9

 In-Ceram
 An alumina core is formed using slip casting
 This core is porous and is then infiltrated with glass
 A dense core is finally produced
 In-Ceram Spinel, In-Ceram Zirconia

Question 10

All porcelain: High strength core ceramics

Answer 10

 Pure alumina

 Pure zirconia

Question 11

All porcelain crowns: CAD CAM

Answer 11

 Newest development in restorative dentistry
 Crown is milled from a single block of porcelain e.g.
Cerec
 Chairside CAD/CAM available
 Reduce human error
 Standardise restoration shaping processes
 Produce higher and more uniform quality material
by using commercially formed blocks of material
 Use of materials that otherwise would be difficult to
use i.e. zirconia, titanium

Question 12

All porcelain crowns

• popuularity
• prep
• aesthetics
• bonding
• shoulder

Answer 12

 Increasing in popularity
 More conservative labial
prep, but more destructive
palatally (1.2mm rounded
shoulder)
 More aesthetic due to
absence of metal
substructure and no metal
showing at margin
 Some can be bonded to
the underlying tooth
(Procera, Empress), but
some cannot (Inceram)
as the high strength
porcelain is not etchable
 The shoulder must be
rounded with no sharp
angles

Question 13

What to use and when

Answer 13

Dentine-bonded crown
Minimally restored tooth
Aesthetics paramount
Suitable occlusion
High-strength porcelain
More heavily restored tooth
Aesthetics more important
Metal-ceramic crown 
More heavily restored tooth
Heavier occlusion (eg bruxism)
Aesthetics less essential

Question 14

Biological width

Answer 14

You need 2mm space above bone as this is where the soft tissue attaches to the bone
If you remove that gingivae you will get inflammation

Question 15

Major consequence of failure of having a crown

Answer 15

Loss of vitality

If the crown is lost, extraction is only option

Question 16

All porcelain: porcelain jacket crowns

Answer 16

Oldest type of all-ceramic crown
Very brittle before cementation
Not very strong type of all-ceramic crown
Very destructive
-thick 2mm feldspathic porcelain
-not used anymore

Question 17

READ FUNDAMENTALS OF FIXED PROSTHODONTICS - HERBERT T. SCHILLINGBURG

Answer 17

• very important

- need to know principles