1.
Ready-made primary anterior
crowns(ZIRKIZ® crowns)
Dr. Sung-Ki Kim
(Developer of ZIRKIZ ®
crowns, South Korea)

2.
Requirements
• Durable
• Retentive
• Esthetic

3.
Ready-made zirconia crowns
• Esthetic
• Strength
• No need for
impression

4.
Zirconia?
• Physical property : close to metal
• Color : tooth-like
• “ceramic steel”

5.
• Thermostable
• Low heat conductivity
• Stable chemical resistance
• Low thermal expansion
• High strength, hardness, abrasion
resistance

6.
C.S(㎫) T.S(㎫)
Composite resin 70~80 30~50
Amalgam 300~500 45~60
GI 93~226 -
Porcelain 150~600 30~60
ZPC 100~160 3~8
ZOE 2~14 -
Ni-Cr - 400~1000
Enamel 270~400 -
Dentin 230~300 40~50
ZIRCONIA 2000 900~1200

7.
Physical and chemical properties
Requirement for
Property Unit ZIRKIZ Value
ISO 13356
Bulk density g/cm3 6.068~6.090 ≥ 6.00
Chemical Composition
ZrO2 + HfO2 + Y2O3 99.60 > 99.0
Y2O3 percent mass 5.35 4.5 to 5.4
HfO2 fraction 3.00 ≤5
Al2O3 0.21 < 0.5
Other oxides* 0.19 < 0.5
Microstructure :
- Mean linear intercept distance ㎛ 0.25 ± 0.05 ≤ 0.4
Maximum amount of monoclinic phase :
- before accelerated aging % 8.12 ≤ 20
- after accelerated aging 15.82 ≤ 25
Biaxial flexure Strength :
- before accelerated aging MPa 1200 ≥ 500
- after accelerated aging 1140 ≥ 500(Decrease not more than 20%)
Radioactivity Bq/kg 2.2 ≤ 200

8.
Biocompatibility
Property Standard ZIRKIZ Value
Cytotoxicity ISO 10993-5 Noncytotoxic
Acute Systemic Toxicity ISO 10993-11 Do not show any systemic toxicity potential.
Oral Mucosa Irritation Do not possess any oral mucosa irritation potential.
ISO 10993-10
Delayed Type Hypersensitivity Do not possess any delayed hypersensitivity.
ISO 10993-10

9.
Soft tissue adaptation by
Zirconia
• A Material That Favors Gingival
Integration
1. Coronary repositioning
2. Papillary reconstruction
3. Scalloped gum
=> Reduced Bacterial Adhesion

10.
Historical Input
• Characteristics of Epithelial tissue
• Characteristics of Connective tissue
• Welander et al.(2008)

11.
Characteristics of Epithelial tissue
• Epithelial cells : proliferation
• Connect to Zirconia via a basal lamina and
hemidesmosomes connections
• Begin 2nd day after operation
• Continue to the apical pole(of the basal
lamina) until they cover zirconia to 2mm

12.
• The newly formed epithelium has all of the
historical characteristics of a normal tooth

13.
Characteristics of Connective
tissue
• Proportion : collagen fiber > fibroblast
• Collagen fiber
– major component of the extracellular matrix
– forms essential framework
– influences the direction of fibroblasts’ growth

14.
5.47
52 51 61 62

15.
• Size : #1, #2, #3, #4
• Shade : original shade(A1), PW(Pedo-
White)

16.
Starter kit

17.
Refill kit

18.
Laser markig(indeliable)

19.
Should be handled by pincette

20.
Advantages
• Esthetics in addition to strength
• Without metal
• Luting available
• Contouring available
• Without facing
• Thin labial structure resembles natural
primary anterior tooth(gingival tissue
adaptation)

21.
• Chair-time decreased
• Bleeding decreased
• Repair available
• 1-visit (sedation) : no impression
• No metal appearance at gingival margin
• Occlusal adjustment available

22.
Indications
• Every cases which needs full coverage in
primary anterior teeth
• Proximal caries in primary anterior teeth
• In case of crowns for primary central
incisor only
• Correction of dental crossbite

23.
Every cases which needs full coverage in primary anterior teeth

24.
Proximal caries

25.
Primary central incisor only

26.
Correction of dental crossbite

27.
Preparation
• Incisal edge
– 2mm reduction
• Proximal surface
– Fit to selected size

28.
• Labiopalatal surface
– The best important part for retention
– “Passive fit”
– Amount of reduction : approximately 15~20%
– At least 2mm subgingivally for the adaptation
with gingiva
– Avoid too much reduction not to be less
retentive

29.
• Reduction of incisal tip

30.
• Reduction of proximal surface

31.
• Reduction of labial surface

32.
• Reduction of palatal surface

33.
• Reduction completed

34.
Cementation
Full-coverage zirconia-based
restorations with adequate
retention do not require resin
bonding for definitive
cementation

35.
Resin bonding, however, may
be advantageous in certain
clinical situations and is a
necessity for bonded
restorations

36.
• Cementation for primary anterior zirconia crowns
– No need of strong adhesive strength like permanent
tooth
– bleeding
– passive fit : hard to hold crowns at proper position
Recommendation : Light-
curing resin cement(or GIC)

37.
Shape adjustment
• Shape adjustment with high-speed diamond bur
• Adjustable after setting of crowns as well as
outside of oral cavity
• Using finishing & polishing kit for porcelain in order
• Should be used with water-cooling when using
high or low-speed bur

38.
-If you grind ZIRKIZ crowns under the red line too much, it can be fractured
because the cervical margin is really thin.

39.
Recommended grinding area and the amount
- area : incisal to the red line
- amount
#A ½
proximal : max. 0.2mm
incisal : max. 0.4mm
- area : incisal to the red line
- amount
#B proximal : max. 0.2mm
½
incisal : max. 0.4mm
Thickness at the red line( ): 0.5~0.6mm

40.
Case Presentation

41.
2010.6.10

42.
After treatment

43.
2010.9.6

44.
2010.11.11

45.
2011.4.16

46.
2011.2.11 Park KB Pre-treatment

47.
After treatment, crossbite corrected

48.
3 months later

49.
6 months later

50.
7 months later

51.
2010.11.22 Kim JY Pre-treatment

52.
After treatment

53.
1 month later