Cementation Flashcards
What to consider with cementation?
Tooth-cement interface
Cement-restoration interface
Characteristics of the ideal cement?
Long working time with rapid set Low film thickness Low solubility High compressive and tensile strengths Low viscosity Adhesion to tooth structure and restorative materials Biocompatible Cariostatic Translucency or opacity when required Radiopaque
Types of acid/base cements?
Zinc phosphate
Zinc polycarboxylate
Glass ionomer
ZO cements
Types of resin modified cements?
Resin modified GIC
PA modified resins
Types of polymeric cements?
Hydrophobic resins
Hydrophilic resins
Self etching resins
Provisional cements
What luting agents are used for conventional cementation?
Conventional cementation Luting agent: - Zinc cements - Glass ionomer cements - Resin modified glass ionomer cements - Polyacid-modified resin composites
When to use conventional cementation?
Metal and metal ceramic restorations
Metal and ceramic endodontic posts
All-ceramic reinforced core ceramics
Zinc phosphate cement advantages?
Easy to mix
Sharp, well-defined set
Low cost
Low film thickness
Zinc phosphate cement disadvantages?
Pulpal irritation due to low pH and exothermic rxns No antibacterial action Brittle and low tensile strength No adhesive qualities Soluble in oral environment
Zinc polycarboxylate cement advantages?
Bond to enamel and dentine and some of the metallic cast restorations Low irritancy Antibac action Low film thickness F release
Zinc polycarboxylate cement disadvantages?
Properties dependent on handling procedures
Short working times and long setting times
Clean up is difficult
Timing critical
Strength and solubility are comparable to zinc phosphate cement
Some adhesion but less than GIC or resins
Types of glass ionomer cements?
Aqua-cem
Fugi1
Katac-cem
Glass ionomer type 1
Glass ionomer cements indications?
20 yrs of success F release Bond to tooth Low expansion/contraction\ Moderate strength
Glass ionomer cements problems?
Some post op sensitivity
Water sensitive during setting
When to use glass ionomer cements?
Good for routine use on crowns and bridges
Suggest the use of a preparation desensitise
Types of resin-modified glass ionomer cements (used today)?
Fugi PLUS
Rely X Luting (used in CCDH)
Protec-cem
Resin-modified glass ionomer cements indications?
F release Bond to tooth Low expansion/contraction Moderate-high strength -tensile and bond strength higher than GIC No post op sensitivity Low solubility - good acid resistance
Resin-modified glass ionomer cements problems?
Swelling
Resin-modified glass ionomer cements use?
Excellent for routine use on crowns and bridges
Contraindicated for most ceramics BUT very good for metal (PFM and gold crowns)
Polyacid-modified resin composites (compomer) strengths?
F release
Bond to tooth with pre-tx moderate - high strength
No post op sensitivity
Low solubility
Polyacid-modified resin composites weaknesses?
Little long term experience
Swelling
Polyacid-modified resin composites use?
Excellent for routine use on metal supported crowns and bridges, lab-made composites
Contraindicated for most ceramics
More modern materials now used
What cementation to use for resin bonded bridges?
What luting agents are used for this?
Etching
Grittblasting
Luting agents - dark cure resins and adhesive resins
Clinical applications of resin to metal bonding?
Resin bonded bridge (adhesive bridge) Ortho bracket Intra-oral repair Fixed partial dentine Composite resin facings
Base metal alloy bonding?
Resin bonded bridge
Ortho bracket
Composite resin facings
Precious metal alloy bonding?
Intra-oral repair
Adhesive bridge
Composite resin facings
Resin/bonded bridge/maryland bridge materials?
Conventional Bis-GMA type resins Chemical/dark cure luting agents Phosphonated resin - panavia 21 4-META based resin Self adhesive resin cements e.g. rely-x unicem
Resin cements - features?
Strong
Adhesive
Technique sensitive (hydrophobic resins)
Available as chemical, dual or light cure
Hydrophobic resins?
For translucent ceramics For adhesive bridges Required bonding agents Light cured or dual cure Wide range of shades and opacities E.g. calibra
Hydrophilic resins?
High affinity to non-precious metals Mainly used for adhesive metal bridges High cost Chemical or dual cure Highly oxygen inhibited E.g. Panavia
Self etch resins?
Easy to use and clean up Strongly self adhesive to dentine Can be used for all crown retained bridges and for bonding provisional adhesive bridges Dual cure E.g. relyX unicem
Silica coating types?
Precious metal bonding
Silicoater
Tribochemical coating - rocatec and cojet
Cojet system materials?
Cojet material
ESPE-Sil
Visio-bond
Sinfony opaquer
Steps to the cojet system - repairing exposed metal?
Pretreat with cojet Apply espe-sil (Silica) cover exposed metal surfaces thinly with sinfony opaquer Light cure 10 sec Apply bonding agent, light cure 20 sec Complete with LC-composite Light cure Finish as usual
cojet system embeds a ceramic layer on the metal surface, porcelain or cured composite, producing a stronger bond as it enables silane coupling.
Conclusions of tribochemical coating?
Technique appears effective in enhancing the bond strength to any alloy
Many steps involved = technique sensitive
Features of metal primers?
Simple to use
Significantly enhance bond strength between precious metal alloys and resin
What procedure and luting agents are used for resin-bonded ceramic (dentine bonded crowns) restorations?
HF etch and silane
Luting agent - aesthetic dual care
Glass-sinlane resin interface?
Sinica glass has OH groups and methacrylate groups
Bonds to get silicaoxide and methacrylate groups
With silane coupling agent it binds to OH groups
Aesthetic resin luting agent types? Light activated and dual cure - uses?
Light activated - porcelite - veneers Dual cure: - Mirage FLC - Nexus - Calibra - Variolink - Rely-X ARC = Ceramic crowns, onlays and inlays
When is resin to resin bond use?
What luting agent is used?
Composite restorations
Fibre reinforced resin bridges
Fribre reinforced endodontic posts
Luting agent - aesthetic dual cure resins, adhesive resins
Resin to resin bond: What occurs when incremental build ups of direct composites are done?
Oxygen inhibited surface layer of some 10-50um thick
Resin to resin bond: What occurs with prefabricated resin composites?
Composite inlays, fibre reinforced bridges and endodontic posts
- Grit blasting or grinding
- HF etching
- Silane coupling agent
- Tribochemical coating
What occurs when a temporary inlay, onlay, crowns and bridges are lost?
Pain
Over eruption and loss of space
Drifting of proximal teeth
Damage to core preparations
Functions of temporary cement?
Provide a seal Prevent marginal leakage Prevent pulpal irritation Low strength to allow easy removal Protect preparation
Ideal properties of temporary cement?
Ability to seal against leakage of oral fluids
Strength consistent with intentional removal
Low solubility
Biocompatibility
Chemical compatibility with provisional polymer
Easy to use
Ease of eliminating excess
Adequate working and setting times
Compatibility with definitive luting agent
Temporary cement examples?
Fine particle zinc oxide eugenol
- Tempbond
Non-eugenol cements
- TempboneNE
Zinc phosphate, zinc polycarboxylate and GIC too high strength - difficult removal, damage to prep
ZOE advantages?
Easy to remove = reuse of restoration
Acceptable sealing properties
Obtundent effect on pulp
Ease of use
ZOE disadvantages?
Free eugenol acts as plasticizer of methacrylate resin and reduces surface hardness and strength
Eugenol can interfere with bond strength of resin cements
All cement removed before using a definitive resin cement
Eugenol free zinc oxid available e.g. Temp bond NE
