Dental Liners, Bases, and Bonding Systems Flashcards
Cavity preparation
The methods used for cavity preparation depon the location, the type restoration and the level of decay involvement– Just the enamel or both the enamel and entin. How much of the tooth structure is cut depend upon the the location, the extent of decay, and the amount of the structure lost to decay or fracture. In general, the natural booth structure that remains, the stronger the tooth will be.
If decay has progressed through the enamel to the dentin, the patient might experience greater sensitivity and discomfort even after a permanent restoration has been seated. This sensitivity and pain manifest almost immediate or up to several months after placement. The dentist will be determine what medication and protection will be placed into the cavity preparation to protect against such a plural response. The dentist will be have liners, varnishes, and bases to that end.
Dental materials to restore tooth structure
two categories.
These materials provide additional protection and contribute to the health of the tooth being restored.
Liners, varnished, bases bases can make a significance difference in postoperative sensitivity and long-term pulpal prognosis when used appropriately.
-Intermediate: includes liners, bases, and cements.
- Supplementary: includes bonding and restorative agents.
pulpal responses
pulpal: found inside the toot, contains the nerve and blood supplies that keep the tooth alive and supplied with nutrients.
There are several stimuli that can trigger an unfavorable response, either reversible or irreversible in the pulp.
- Physical: electrical, thermal
- mechanical occlusion: trauma, handpiece
- chemical: dental material acid.
- Biological: saliva bacteria.
The response in the pulp cause by stimuli sometimes can be lessened.
Dental liners: material is laid in a thin layer that protects the pulp from irritation caused by biological, chemical, mechanical and physical elements.
Liners help protect the pulp from irreversible irritation that might lead to endodontic therapy or even extraction,
Calcium hydroxide
Calcium hydroxide commonly used a dental liner. There are certain indications for using Calcium hydroxide.
Calcium hydroxide should be applied directly only to the deepest portion of the pulpal floor in the preparation. It should be placed only on dentin
- Indication for using Calcium hydroxide
- pulpal chemical irritation is avoided because of its sealing capabilities.
- secondary dentin production is stimulated.
- it can be used with all types of restorative materials.
- Calcium hydroxide is places over the deepest portion of pulpal floor and only on dentin.
Varnish
Varnish: a liquid consisting of one or more resins in a organic solvent applied to the internal preparation structure.
There are certain indications for Varnish and Varnish should be applied using specific process.
-indications for using varnish
- dentinal tubule sealing
*Restoration leakage reduction
- protection against highly acidic cements such as zinc phosphate.
-Varnish application process:
- Apply to varnish with dry cotton pellet or microbrush.
*Place a thin coating on the internal walls, floor, and margin of a cavity preparation.
- Allow the surface to air dry.
- a second application is recommend
Dentin sealer
there are certain indications for the use of dentin sealer.
- can be used for treatment or prevention of hypersensitivity
-can be use as alternative to varnish
- can be used in dentinal tublue sealing
- can be used under all indirect restorations
guidelines
- do not apply toot much material
- avoid soft tissue contact
-apply with cotton tipped applicator
- apply over all area of exposed dentin
types of base minerals
each dental base provides a different types pulpal protection. different types of base minerals are
- zinc oxid-eugenol (ZOE)
-zinc phosphate
- polycarboxylate
- class ionomer
when using a base, the varnish or sealer is places over the base. A bonding agent is placed over the base.
-Protective: protects the pulp before a large restoration.
-Insulating: Thermal shock protection.
-sedative: soothes pulp that has been irritated by decay or mechanical means.
dental bonding
dental bonding: creates micro-mechanical retention between tooth. structure and restoration.
Bonding agents: enable the removal of less tooth structure before definitive restoration placement because minimal retentive features are needed.
Direct bonding: Is achieved by way of removal of the smear layer with etchant.
Etching system
Etching system are used in smear layer removal to prepare for bonding; they are sold as either a gel or a liquid acid that will brushed or wiped onto the tooth surface.
proper isolation of the teeth to be treated is necessary. since acid contact with skin or soft tissues will cause a burn and irritation.
The acid etchant is usually 35% phosphoric acid gel. also the acid etchant is often colored blue for example to make it easier to see where it has been placed ad whether or not it has been completely washed off.
Eching system are supplied as
- lquid/gel
- maleic acid
- phosphoric acid
Clinical Application of etching and bonding systems
There are certain clinical indications for the use of etchant and bonding system
- remove plaque and debris prior to bonding process.
- remove the smear layer with use of etchant.
- Rinse and dry the tooth structure (avoid over-drying etching teeth)
- cover all surface will bonding solution ( too much bonding is better than too little)
- avoid contamination form saliva ( the entire procedure will need to be redone if v occurs).
- Allow for maturation of bonding material (maturation needs to occur before restoration is considered complete?.
Enamel bonding
Enamel bonding is used when a bond is needed on the intact enamel surface. it is used for orthodontic brackets, dental sealants, and for resin bonded veneers and bridge.
Sealants material held in place by the occlusal developmental grooves.
Bonded veneers are for example of an esthetic option available to an individual who wants to change the shapes, size and color of the teeth. A very small later of facial enamel is removed, followed by an impression that allows the dental laboratory to fabricate a new facial surface in porcelain, is bonded permanently to prepared teeth.
example of enamel boningL
- sealants
- placement of orthodontic brackets
- maryland bridges
-veneers
Supplementary and dental materials
It is important to remember that the treatment plan often changes after a tooth is physically opened up and evaluated.
The information shown includes the order of application for the material. according to cavity preparation depth.
-Amalgam:
*shallow
1. dentin sealer
2. bonding system
- moderately deep
1. base
2. dentin sealer
3. bonding system
-composite resin
*Shallow
1. bonding system
- moderately deep
1. bonding system - Percious metals (gold) inlays or onlays
*Shallow N/A - moderately deep:
1. base
-porcelain or ceramic
*Shallow
1. bonding system
- moderately deep
1. bonding system
Cement classifications
Cement classifications: brittle material is made by mixing a liquid with a powder; it acts as a luting agent, protects that pulp or lines the cavity preparation. used in placement of indirect restorations.
Three classifications of cements:
-Type I: luting agents; temporary or permanent cements.
-Type II: restorative materials, such as glass ionomer
-Type II: liners or bases placed with cavity preparation.
Type I dental cements or luting agents acts as adhesives that bond the metal casting to tooth surface.
Permanent or temporary cements
Restoration cements are designed to create a Permanent or temporary cements.
-Permanent cements: this is used to bond gold and ceramic restorations such as inlays/onlays, crowns, bridges, veneers, and orthodontic fixed appliances for the life of restoration.
-temporary cements: This is used until restoration would need to be removed as a result of sensitivity or other symptoms; also used for provisional coverage.
types of cements
- glass ionomer
- composite resin
-zinc oxide-eugenol
-polycarboxylate - zinc phosphate
