Cementation options
Temporary cements Adhesive cements Non adhesive
Provisional Cements
Ideal properties for provisional cements
- Low strength
- no effect on dental pulp
- easy to use
- easy to remove
- Don’t interfere with the permanent restoration
composition
- Mostly based on zinc oxide
- with or without eugenol
Cements containing eugenol
- Have an anodyne effect on the pulp
Eugenol inhibits free radicals which are necessary to initiate addition polymerisation of resin-based composite and dentine bonding systems This includes IRM (Polymer reinforced ZnOE)
- ZnOE cements will only set in the presence of water
Definitive cements
Cementation (Luting) vs Bonding (Adhesive)
Conventional Luting cements
- Zinc phosphate
- Zinc polycarboxylate
Zinc phosphate
Strengths:
- used for 100 years
- Application is less technique sensitive Weaknesses
Zinc polycarboxylate
Strengths:
- used for 100 + years
- some fluoride ion relase
- Adhesion to tooth substance
- low post-op sensitivity
- easy to use Weaknesses:
- Medium hardness
- Somewhat soluble
- Some weak bonding to tooth
GIC
Strengths:
- 30+ years of use
- Fluoride ion release
- Bonding to tooth
- Dimensionally stable
- Adequate strength Weaknesses:
- Low PH occasional post-op sensitivity
RMGIC
Weaknesses:
- Shorter shelf life
- hygorscopoic swelling wiht exposure to water
- Not suitable for weaker ceramic restorations due to hygroscopic expansion with time.
Strengths:
- easy to use
- bonding to tooth
- low solubility
- adequate strength
- less technique sensitive than composite cements
- low post-op sensitivity
Composite resin cements
Strengths:
- 10 years of use
- Good adhesion (with bonding and self-etch)
- Bond to ceramic (with apprpriate pre-treatments)
- Good aesthetics Weaknesses:
- !0 years of use
- multi step
- technique sensitive
- Bonding with deep subingingival margins
Resin cements:
- Composite based and can be:
- self cure
- light cure
- dual cure
- Self adhesive
- require adhesive steps
Basic properoties of dental luting cements
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GC Luting and cements
Examples of brand names
- G-cem one
- G-CEM capsules
- G-cem linkforce
- G-Cem veneer
- Fuji plus luting
- G-multi-primer
Crown insert procedure
- Lots of synonyms
- Crown fit
- Crown insert
- Crown fit etc
Decision dpeends on the clinical situation
- the restoration
- the tooth
- the patiet
- operator factors
Restorative material
- Metal
- PFM
Preciouscious and non-precious metal
- Prcious (gold alowys) >60% noble metal
- Semi-precious (>25% noble metal)
- Non-precious (<25% noble metal. Nickel, Cobal, Chromium, Beryllium)
- 4g approx 40
**Cementing:
- cement iwth any cement if suffiicent mechanical retention
- If there is insufficient mechanical retention:
- MDP primer will bond resin cements to noble alloys but the bond is more reliable with non precious alloy.
- MDP is not new (introduced 20+ years ago)
- …
Glass ceramics (e.max)
- Because of its reduced strength compared to zirconia consider bonding e.max
- If it’s thick enough with adequate mechanical retention especially with subgingival margins, it ca be cemented conventionally.
- Pressed glass is stronger than milled particularly hwen bonded
- Mechanically unretentive restorations require bonding with adhesive cement
To achieve bonding to e.max with resin cement:
- Ask lab to air abrade and etch fit surface with hydrofluoric acid (chairside is preferable)
- clean with Ivo clean after trying in
- Silane on fit surface
- Bond with resin cement - self etching or with dentine bonding
**Silane bonding agents
- Bifunctional (bipolar) Molecules
- Hydrolyzable group
Prime and bond options at OCHWA
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Monobond Etch and Prime One step: combines etching via ammonium polyfluoride and silaniztion into a single liquid
Zirconia
Types of Zironica [INSERT PIC HERE]
Cementing vs bonding zirconia ?
zirconia and silane
Unlike lithium disilicate, silane doesn’t bond to zirconia
APC concept in zironcia bonding
Immediate dentine sealing
- Dentine bonding with a more filled resin
- or cna use a thin layer of flowable composite = reinforced IDS