Dental cements (Ch 14) Flashcards
when are dental cements used in dentistry
- cavity varnish: closes tubules and decreases microleakage, used under amalgam only
- liners: placed in a thin layer, stimulates reparative dentin, for very small pulp exposure, eg calcium hydroxide = ducal
- bases: placed in a thick layer, protects against chemical, thermal, physical irritation
what is luting
- refers to the cementing of 2 components together
- ex. inlays, crown and bridge, veneers, orthodontic brackets and bands
what are luting agents for
- temporary crown and bridge
- permanent crown and bridge
- attach orthodontic bands and brackets to enamel
what are surgical dressings
- provides protection and support for surgical sites, provide patient comfort and control bleeding
what are type 1 luting agents
- act as an adhesive to hold together the casting to the tooth structure
- luting agents are designed to be either permanent or temporary
what is permanent luting cement
- for the long-term cementation of gold and ceramic restorations such as inlays/onlays, crowns, bridges, veneers, orthodontic fixed appliances
what is temporary luting cement
- temporary cements are used if the restoration would have to be removed due to sensitivity or other symptoms, and for the temporary cementation of provisional coverage
review properties of dental cements in the ppt
- slides 11 and 12
what are 6 commonly used cements
- zinc-oxide eugenol
- zinc phosphate
- zinc polycarboxylate
- glass ionomer
- hybrid ionomer
- composite resin
what are some advantages to zinc oxide eugenol
- wide variety of uses: for temp cementation, for temp and immediate rest, low strength bases, root canal sealants, perio dressings
- sedative to the pulp
- easily manipulates
what are some disadvantages to zinc oxide eugenol
- low strength
- high solubility
what are the 2 types of zinc oxide eugenol
- type I: lacks strength and long‑term durability and is used for temporary cementation of provisional coverage
- type II: has reinforcing agents added for the permanent cementation of cast restorations or appliances
what is zinc phosphate
- acid-base reaction
- made of zinc oxide
- power/liquid system
- exothermic reaction (chemical reaction) occurs. mixing of powder & liquid is done in increments to control heat
what are the two different types of zinc phosphate
- fine grain: used for the permanent cementation of cast restorations such as crowns, inlays, onlays, and bridges. this material creates the very thin film layer necessary for accurate seating of castings
- medium grain: recommended for use as an insulating base for deep cavity preparations
what are some advantages of zinc phosphate
- long clinical history
- low film thickness
- inexpensive
- high rigidity
what are some disadvantages of zinc phosphate
- initial pulp irritation
- mechanical bond only
- technique-sensitive mixing
- relatively high solubility
what is zinc polycarboxylate cement and what is it used for
- permanent cement for cast restorations, stainless steel crowns, and orthodontic bands
- as a nonirritating base under both composite or amalgam restorations
- as an intermediate restoration
what are some advantages of zinc polycarboxylate
- bonds directly to tooth structures
- nonirritating to the pulp
- inexpensive
what are some disadvantages of zinc polycarboxylate
- higher solubility
- lower strength
- shorter working time
what are glass ionomers
- chemically bond to tooth structure
- release and replenish fluoride
- contain aluminum fluorosilicate glass
- powder/liquid or capsules (triturate)
what are the 3 different types of glass ionomers
- type: 1 for the cementation of metal restorations and direct‑bonded orthodontic brackets
- type II: designed for restoring areas of erosion near the gingiva
- type III: used as liners and dentin bonding agents
what are some benefits of glass ionomers
- powder is an acid‑soluble calcium. the slow release of fluoride from this powder aids in inhibiting recurrent decay
- causes less trauma or shock to the pulp than many other types of cements
- low solubility in the mouth
- adheres to a slightly moist tooth surface
- has a very thin film thickness, which is excellent for seating ease
what forms does glass ionomer come in
- powder/liquid: mixed manually on a paper pad or a cool, dry glass slab. glass slab increases the working time of the cement
- premeasured capsules: triturated and expressed through a dispenser
what are some advantages to glass ionomers
- chemical adhesion to tooth
- fluoride release
- easy to mix
- moderate strength
what are some disadvantages to glass ionomers
- history of postoperative sensitivity
2. moisture sensitive during setting
what are some advantages to hybrid ionomer cements
- good strength
- fluoride release
- insoluble
- chemical adhesion to tooth
- less postoperative sensitivity
- excellent film thickness
what are some disadvantages to hybrid ionomer cements
- not recommended for all ceramic restorations
what is composite resin cement and when is it used
- cementation of ceramic or resin inlays and onlays
- cementation of ceramic veneers
- cementation of orthodontic bands
- direct bonding of orthodontic brackets
- cementation of all metal castings
what forms does composite resin come in
- powder and liquid mix
- syringe-type applicator
- base and catalyst
- light cure/dual cure system: recommended portions of either application are dispensed onto a paper pad and mixed rapidly with a spatula
what are some advantages to resin-based cements
- high strength
- insoluble
- low wear
- excellent bond
- aesthetic shades available
what are some disadvantages to resin-based cements
- requires additional steps in the bonding procedure
- requires additional steps in preparation of internal restoration surfaces
- removal of excess cement may be difficult
what is the cement removal process like
- operator preparedness and knowledge
- instruments selected for the procedure:
- explorer, mouth mirror, excavator
- use a fulcrum
- use knotted dental floss in and around the embrasure areas
read ‘removal of excess cement’
- slide 34 in ppt
what do surgical dressing for gingival grafts provide
- protection
- support for the surgical site
- patient comfort
- helps in the control of bleeding
what is the criteria for a well-placed dressing for gingival grafts
- smooth with as little bulk as possible
- covers the surgical site with minimal overextension
- interlocked interdentally to provide stability
