Dental Cements: Luting Agents Flashcards
Why use \_\_\_\_\_\_? Caries Fractures Misalignment Prolong the life of the pulp in the war against oral bacteria- using protective coatings Varnish Base Liner Pits & Fissure sealants
Dental Cements
Substance that hardens to act as a base,
liner, restorative material or luting agent
(adhesive) to bind devices and prostheses
to tooth structure or to each other
Dental cement
What do we want a Dental
Cement to be?
① Biocompatible- long-term ② Non-corrosive & Inert ③ Immune to acid attack • insoluble ④ Dimensionally stable- • no cracking of tooth or device by expansion • no leaking because of shrinkage 5) Sets during the dental procedure 6) Low surface tension; Handles & places easily 7) Adapts & adheres to anatomy 8) Insensitive to moisture during procedure 9) Anti-microbial/ F- release 10) Radiopaque- able to see it on a radiograph 11) “Cost-effective” HIGH values needed for: 13) Cyclic fatigue 14) Thermal cycling 15) STRENGTH a. Tensile b. Compressive c. Flexural Strength d. Shear
Applications of _______
- Luting cements
a. Permanent & provisional indirect restorations
b. Orthodontic brackets
c. Post and cores - Restorative materials
a. Permanent & provisional direct restorations - Cavity liners & Bases
a. Pulp protection - Multiple applications
a. No one cement can fulfill all requirements
Dental cements
Viscous material that fills the
microscopic space between the abutment-
prosthesis interface; upon setting, it forms a
solid that seals the space and retains the
prosthesis.
Luting cement/agent
What are the 8 ideal properties of a permanent luting agent?
- *Low film thickness (25 m)
- *Adequate strength (minimum 70 MPa)
- *Low solubility (0.2% max. @ 24h)
- *Reasonable setting time (2.5-8.0 min)
- Adequate working time
- Biocompatible, does not irritate pulp
- Cariostatic
- Adhesion to tooth structure and restorative materials
_____ bonding
very weak interaction, 2bonds
Van der Waals forces, hydrogen bonds
Physical bonding
_____ bonding
: strongest bond, 1bonds
Limited occurrence, dissimilar materials
Example: composite bond to adhesive bond agent
Chemical bonding
\_\_\_\_\_ bonding :interlock undercuts, surface irregularities Micromechanical retention Examples: Luting agent/tooth/crown Adhesive bond agent/tooth
Mechanical bonding
Cement locking into microscopic irregularities in prepared
tooth surface and the internal surface of the crown
Non-resin cements
Very low bond strength, 1-5 MPa
Luting cement:
Enamel: resin tags into etched enamel
Dentin: hybrid layer
Interdiffusion or micromechanical interlocking of resin with demineralized collagen of interbulular dentin
20-30 MPa bond strength
Adhesive bond agent/tooth:
Is the liquid or powder the acidic component of cement?
Liquid
Is the liquid or powder the basic component of cement?
Powder
_____ cement:
Indications
Temporary / intermediate
cementation
Zinc oxide eugenol
- Composition:
a. Powder: Zn Oxide Liquid: Eugenol
b. Modifications:
1) Polymer-reinforced: IRM
2) EBA (ethoxy-benzoic acid), Alumina - Low strength (MPa):
- Uses: temporary or provisional cement
and restorations
a. Eugenol acts as sedative, obtundent - ZOE unmodified, TempBond
a. Temporary cement - ZOE polymer-reinforced
a. IRM: Intermediate Restorative Material
1) Temporary cement: Retention or time
2) Provisional/intermediate restoration - Not use prior to resin-based permanent cement,
ZOE