Dental Liners, Bases, and Bonding Systems Chapter 44 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved

Dental Liners, Bases,Dental Liners, Bases,and Bonding Systemsand Bonding Systems

Chapter 44Chapter 44

Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.


Lesson 44.1Lesson 44.1


Learning ObjectivesLearning Objectives

Pronounce, define, and spell the Key Terms.Pronounce, define, and spell the Key Terms. Discuss how the sensitivity of a tooth Discuss how the sensitivity of a tooth

determines the type of dental material that is determines the type of dental material that is selected for a procedure.selected for a procedure.

Discuss how and why cavity liners are used in Discuss how and why cavity liners are used in restoring tooth structure. restoring tooth structure.

(Cont’d)(Cont’d)




Apply calcium hydroxide to a prepared tooth Apply calcium hydroxide to a prepared tooth surface.surface.

Discuss how and why varnishes are used in Discuss how and why varnishes are used in restoring tooth structure.restoring tooth structure.

Apply dental varnish to a prepared tooth Apply dental varnish to a prepared tooth surface.surface.


IntroductionIntroduction

Dental liners, bases, and bonding systems Dental liners, bases, and bonding systems

are a supplemental classification of dental are a supplemental classification of dental

materials that provide additional materials that provide additional

protection for the health and well-being protection for the health and well-being

of the tooth being restored.of the tooth being restored.


Prepared Tooth StructuresPrepared Tooth Structures

Design of the cavity preparation Design of the cavity preparation Provides strength within the tooth Provides strength within the tooth Helps determine how the tooth will hold the Helps determine how the tooth will hold the

restoration in placerestoration in place


Type of StimulusType of Stimulus ExampleExample

PhysicalPhysical Thermal, electrical Thermal, electrical

Mechanical occlusionMechanical occlusion Handpiece, traumaticHandpiece, traumatic

ChemicalChemical Acid from dental Acid from dental materialsmaterials

BiologicBiologic Bacteria from Bacteria from salivasaliva

Pulpal Responses Pulpal Responses


Dental liners provide a thin barrier to Dental liners provide a thin barrier to

protect the pulpal tissue from irritation protect the pulpal tissue from irritation

caused by physical, mechanical, caused by physical, mechanical,

chemical, and biologic elements.chemical, and biologic elements.

Dental LinersDental Liners


Calcium HydroxideCalcium Hydroxide

Indications for useIndications for use Protects the pulp from chemical irritation by way of Protects the pulp from chemical irritation by way of

its sealing ability its sealing ability Stimulates the production of reparative or secondary Stimulates the production of reparative or secondary

dentin dentin Compatible with all types of restorative materials Compatible with all types of restorative materials

Application processApplication process May be an advanced function in your stateMay be an advanced function in your state Placed directly over the deepest portion of the Placed directly over the deepest portion of the

preparation preparation Placed only on dentinPlaced only on dentin


Fig. 44-1 Placement of a liner.Fig. 44-1 Placement of a liner.


VarnishVarnish

Varnish is a liquid consisting of one or Varnish is a liquid consisting of one or

more resins in an organic solvent applied more resins in an organic solvent applied

to the internal preparation structure. to the internal preparation structure.


VarnishesVarnishes

Indications for use*Indications for use* Sealing dentinal tubules Sealing dentinal tubules Reducing leakage around a restoration Reducing leakage around a restoration Acting as a barrier to protect the tooth from highly Acting as a barrier to protect the tooth from highly

acidic cements such as zinc phosphateacidic cements such as zinc phosphate

* This material is contraindicated in its use * This material is contraindicated in its use under composite resins and glass ionomer under composite resins and glass ionomer restorations. restorations.



VarnishesVarnishes


Application processApplication process Applied with the use of a small disposable Applied with the use of a small disposable

applicator or a cotton pelletapplicator or a cotton pellet Thin coating placed on the internal walls, floor, Thin coating placed on the internal walls, floor,

and margin of a cavity preparation and margin of a cavity preparation Allowed to air dryAllowed to air dry Second application recommended Second application recommended


Fig. 44-3 Location for placement of cavity varnish.Fig. 44-3 Location for placement of cavity varnish.






Discuss how and why dentin sealers are used Discuss how and why dentin sealers are used in restoring tooth structure.in restoring tooth structure.

Apply a dentin sealer to a prepared tooth Apply a dentin sealer to a prepared tooth surface.surface.

Discuss how and why dental bases are used Discuss how and why dental bases are used in restoring tooth structure. in restoring tooth structure.

Mix and place three types of bases on a Mix and place three types of bases on a prepared tooth surface.prepared tooth surface.


Dentin SealerDentin Sealer

Indications for useIndications for use Treatment or prevention of hypersensitivityTreatment or prevention of hypersensitivity Instead of a varnish Instead of a varnish Sealing of the dentinal tubules Sealing of the dentinal tubules Ideal for use under all indirect restorationsIdeal for use under all indirect restorations

Application processApplication process Use the material sparingly. Use the material sparingly. Do not allow the material to make contact with soft tissues Do not allow the material to make contact with soft tissues

(HEMA and glutaraldehyde).(HEMA and glutaraldehyde). Apply the dentin sealer with the use of a cotton-tipped Apply the dentin sealer with the use of a cotton-tipped

applicator. applicator. Apply the sealer over all areas of exposed dentin.Apply the sealer over all areas of exposed dentin.


Dental BasesDental Bases

Dental bases provide different types of pulpal Dental bases provide different types of pulpal protection:protection: Protective: protects the pulp from a large Protective: protects the pulp from a large

restorationrestoration Insulating: protects the tooth from thermal shockInsulating: protects the tooth from thermal shock Sedative: soothes pulp that has been damaged by Sedative: soothes pulp that has been damaged by

decay or irritated by mechanical means. decay or irritated by mechanical means.


Types of Base MaterialsTypes of Base Materials

Zinc oxide–eugenol (ZOE) Zinc oxide–eugenol (ZOE) Zinc phosphate Zinc phosphate PolycarboxylatePolycarboxylate Glass ionomer Glass ionomer


Fig. 44-5 Location for placement of a base.Fig. 44-5 Location for placement of a base.






Describe the tooth-etching process and its Describe the tooth-etching process and its importance in the bonding of tooth and importance in the bonding of tooth and material.material.

Describe bonding systems and how they Describe bonding systems and how they provide a better adherence of dental provide a better adherence of dental materials to the tooth structure.materials to the tooth structure.

Apply etchant material. Apply etchant material. Apply a bonding system to the prepared tooth Apply a bonding system to the prepared tooth

structure.structure.


Dental bonding improves retention by Dental bonding improves retention by

creating a micromechanical retention creating a micromechanical retention

between the tooth structure between the tooth structure

and the restoration.and the restoration.

Dental BondingDental Bonding


Enamel Bonding Enamel Bonding

Enamel bonding is placed directly on the Enamel bonding is placed directly on the intact enamel surface.intact enamel surface.

Examples of enamel bonding Examples of enamel bonding SealantsSealants Bonded orthodontic bracketsBonded orthodontic brackets Resin‑bonded bridgesResin‑bonded bridges Bonded veneers Bonded veneers


Dentin BondingDentin Bonding

Dentin bonding is placed on the prepared Dentin bonding is placed on the prepared dentin for the bonding of a restorative dentin for the bonding of a restorative material to tooth structure.material to tooth structure.

Smear layerSmear layer Thin layer of debris Thin layer of debris ““Nature’s bandage”Nature’s bandage”


Etching SystemsEtching Systems

Etching systems are used to remove the Etching systems are used to remove the smear layer in preparation for bonding. smear layer in preparation for bonding.

Supplied as:Supplied as: Liquid/gelLiquid/gel Maleic acidMaleic acid Phosphoric acidPhosphoric acid


Clinical Application of the Etchant Clinical Application of the Etchant and Bonding Systemsand Bonding Systems

Plaque or debris is removed before the Plaque or debris is removed before the bonding process. bonding process.

Etchant is applied to remove the smear layer. Etchant is applied to remove the smear layer. The tooth structure is rinsed and dried (avoid The tooth structure is rinsed and dried (avoid

overdrying etched teeth). overdrying etched teeth). All surfaces are covered with onding solution.All surfaces are covered with onding solution. Too much bonding is better than too little.Too much bonding is better than too little. Contamination with saliva requires the entire Contamination with saliva requires the entire

procedure to be redone. procedure to be redone. Allow time for the bonding material to mature Allow time for the bonding material to mature

before completing the restoration.before completing the restoration.


Table 44-1 Supplementary Dental Materials and Table 44-1 Supplementary Dental Materials and Application in Order of Use.Application in Order of Use.


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Dental Liners, Bases, and Bonding Systems Chapter 44 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved