This document provides information on ready-made primary anterior zirconia crowns called ZIRKIZ crowns. It discusses that zirconia crowns are esthetic, strong and do not require dental impressions. The document reviews the physical and chemical properties of zirconia and its biocompatibility. It describes how zirconia favors gingival integration and outlines the advantages, indications, preparation, cementation and shape adjustment of ZIRKIZ crowns. Case presentations show examples of using the crowns to correct dental issues like crossbite in primary teeth.
10. 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
11. 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
12. Soft tissue adaptation by
Zirconia
• A Material That Favors Gingival
Integration
1. Coronary repositioning
2. Papillary reconstruction
3. Scalloped gum
=> Reduced Bacterial Adhesion
14. 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
15. • The newly formed epithelium has all of the
historical characteristics of a normal tooth
16. 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
29. 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)
30. • Chair-time decreased
• Bleeding decreased
• Repair available
• 1-visit (sedation) : no impression
• No metal appearance at gingival margin
• Occlusal adjustment available
31. 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
37. • 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
44. Resin bonding, however, may
be advantageous in certain
clinical situations and is a
necessity for bonded
restorations
45. • 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)
46. 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
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51.
52. -If you grind ZIRKIZ crowns under the red line too much, it can be fractured
because the cervical margin is really thin.
53. 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