Restorative and Esthetic Dental Materials Chapter 43Presentation Transcript
Chapter 43 Restorative and Esthetic Dental Materials Copyright 2003, Elsevier Science (USA). All rights reserved. No part of this product may be reproduced or transmitted in any form or by any means, electronic or mechanical, including input into or storage in any information system, without permission in writing from the publisher. PowerPoint ® presentation slides may be displayed and may be reproduced in print form for instructional purposes only, provided a proper copyright notice appears on the last page of each print-out. Produced in the United States of America ISBN 0-7216-9770-4
Introduction Restorative dental materials fulfill an important role in the way dentistry is delivered today.
ADA: criteria for a new material
Must not be poisonous or harmful to the body.
Must not be harmful or irritating to the tissues of the oral cavity.
Must help protect the tooth and oral tissues of the oral cavity.
Must resemble the natural dentition.
Must be easily formed and placed in the mouth.
Standardization of Dental Materials
Mechanical properties must withstand the biting and chewing force in the posterior area of the mouth.
Force is any push or pull on matter.
Stress is the reaction within the material that can cause distortion.
Strain is the change produced within the material that occurs as the result of stress.
Properties of Dental Materials
Types of stress and strain:
Tensile stress pulls and stretches the material.
Compressive stress pushes the material together.
Shear stress is the breakdown of the material.
A change in temperature in the oral cavity due to either a hot or cold product.
Contraction and expansion
Dental materials will contract or expand at their own rate.
Change in temperature can cause a dental material to pull away from the tooth.
An electrical current, or galvanic action, is created when two different or dissimilar metals are present in the oral cavity.
Two metallic components of different composition.
Galvanic action, or shock, is the coming together of all conditions.
Reaction a metal has when it comes into contact with corrosive products.
Solubility is the degree to which a substance will dissolve in a given amount of another substance.
The dental material must be pliable enough to be placed in the preparation.
The force that causes unlike materials to adhere to each other.
Wetting is the ability of a liquid to flow over the surface.
Viscosity is the property of a liquid that causes it not to flow easily.
Surface characteristics is where a liquid flows more easily on a rough surface than on a very smooth surface.
Film thickness: In general, the thinner the film, the stronger the adhesive junction.
Retention is the ability to hold two things firmly together when they will not adhere to each other.
Auto-cured material hardens as the result of a chemical reaction of the materials.
Light-cured material does not harden until it has been exposed to a curing light.
Application Properties cont’d
Restorative: To replace or bring something back to its natural appearance and function.
Esthetic: To replace or bring something back to its pleasing appearance.
Restorative and Esthetic Materials
Restorative materials that are applied to the tooth while the material is pliable and able to carve and finish.
Intermediate restorative materials
Amalgam is a safe, affordable, and durable material that is used predominantly to restore premolars and molars (Figure 43-8).
Fig. 43-8 Packing an amalgam carrier.
In individuals of all ages.
In stress-bearing areas of the mouth.
When there is severe destruction of tooth structure.
As a foundation.
When personal oral hygiene is poor.
When moisture control is problematic.
When cost is an overriding patient concern.
Indications for Using Amalgam
Indications for Not Using Amalgam
Esthetics is important.
Patient has a history of allergy to mercury or other amalgam components.
The cost of other restorative materials or treatment options is not a factor.
Mercury (43% to 54%)
Alloy powder (57% to 46%)
Silver, which gives it its strength.
Tin for its workability and strength.
Copper for its strength and corrosion resistance.
Zinc to suppress oxidation.
Chemical Makeup of Amalgam
Harm to patients: Essentially harmless.
The exception is with patients who have many amalgam restorations, or a high sensitivity to metals.
Harm to Dental Personnel: Health concerns with high exposure to mercury, not amalgam.
Nervous system disorders
Issues Concerning Amalgam
Do not contact mercury with your skin.
Protect against spillage during trituration.
Keep lid closed during trituration.
Do not discard scrap amalgam into waste containers.
Collect all scrap amalgam and store under water or photographic fixer solutions in a closed container.
Capsules (600 mg of alloy): For small or single‑surface restorations.
Capsules (800 mg of alloy): For larger restorations .
Trituration : The process by which the mercury and alloy are mixed together to form the mass of amalgam.
Preparation of Amalgam
Mixed amalgam placed in amalgam well.
Amalgam carried to the prepared tooth.
Amalgam placed in increments in the prepared tooth.
Each increment is condensed immediately.
Carvers are used to carve anatomy into the amalgam.
A burnisher is used to smooth the amalgam.
The new restorations occlusion is checked.
Direct Application of Amalgam
Becoming the most widely accepted material of choice by dentists and patients because of their esthetic qualities and new advances in their strength (Figure 43-13).
Fig. 43-13 Resins supplied in a syringe.
Withstand the environments of the oral cavity.
Be easily shaped to the anatomy of a tooth.
Match the natural tooth color.
Be bonded directly to the tooth surface.
Indications for Using Composite Resins
Dimethacrylate, referred to as BIS‑GMA
Monomer used to make synthetic resins
Allow the material to take form through a chemical process
Ultraviolet (UV) stabilizers
Chemical Makeup of Composite Resins
Fillers Add the strength and characteristics necessary for use as a restorative material.
Chemical Makeup of Composite Resins cont’d
A coupling agent strengthens the resin by chemically bonding the filler to the resin matrix.
Chemical Makeup of Composite Resins cont’d
Macrofilled composites contain the largest of filler particles, providing greater strength but a duller, rougher surface.
Microfilled composites: The inorganic filler is much smaller and is capable of producing a highly polishee, finished restoration, which is used primarily in anterior restoration.
Hybrid composites contain both macrofill and microfill particles.
Types of Composites
The process in which the resin material is changed from a plastic state into a hardened restoration.
Polymerization of Composite Resins
Select the shade of the tooth.
Express the needed amount of material onto the treated pad or in the light-protected well.
Material placed in increments.
Material is light-cured.
Material is finished and polished.
Direct Application of Composite Resins
Reduction of the material is completed by the use of a white stone or a finishing diamond.
Fine finishing is completed with carbide finishing burs and diamond burs.
Polish with medium discs and finish with the superfine discs.
Finishing strips assist in the polishing of the interproximal surfaces.
Use polishing paste with a rubber cup.
Steps in Finishing a Composite Restoration
Glass ionomer is a versatile material with chemical properties allowing it to be a restorative material, liner, bonding agent, and permanent cement.
Glass Ionomer Materials
Final restorations in non-stress areas.
Core material for a buildups.
Long-term temporary restorations.
Indications for Using Glass Ionomers
The ability to chemically bind to the teeth.
No need to prepare the tooth structure as extensively as for preparing for an amalgam or composite resin.
The release of fluoride after its final setting.
Qualities of Glass Ionomers
Metal-reinforced glass ionomer
Silver-tin alloy + Glass ionomer
Properties of Glass Ionomers
Powder and Liquid: Manually mixed together on a treated paper pad.
Light-Protected Tubes: Dispensed onto a treated paper pad.
Paste/Paste System: Mixed for application.
Premeasured Capsule: Triturated for application.
Supply of Glass Ionomers
Designed to maintain or restore function to a tooth or teeth and keep the patient comfortable for a period of time.
Temporary Restorative Materials
Reduce sensitivity and discomfort of a tooth to determine its diagnosis.
Maintain the function and esthetics of a tooth until a permanent restoration can be placed.
Protect the margins of a prepared tooth that will receive a permanent casting at a later time.
Prevent shifting of the adjacent or opposing teeth because of open space.
Indications for Using a Temporary Restorative Material
Zinc-Oxide gives strength and durability.
Eugenol has a sedative effect.
Intermediate Restorative Materials (IRM)
Restoration of primary teeth
Caries management program
Supply of IRM
Indications for Using IRM
Restorative material that covers the major portion, if not the entire clinical portion of a tooth or several teeth for a period of time .
Provisional Restorative Materials
Auto-cured acrylic (methylmethacrylate)
Process of application
Material is placed in either an alginate impression or a vacuum-formed tray.
Material is seated over the prepared tooth and allowed to cure.
Occlusion is adjusted.
Material is cemented in place with temporary cement.
Types of Materials Used
The process of applying a material on anterior teeth for a prescribed period of time to whiten the color of one’s teeth.
Tooth Whitening Materials
Consumption of staining substances
Indications for Using Tooth-Whitening Products
Carbamide Peroxide: When the carbamide peroxide breaks down, oxygen enters the enamel and dentin and bleaches the colored substances.
Concentrations: 10%, 16%, 22%
Types of dental restorations that dental laboratory technicians create in the dental laboratory.
These restorations are also referred to as castings, cannot be reshaped, and are carved once they are in this stage.
By combining gold with other metals to form an alloy, it creates the characteristics and hardness required as an excellent choice for an indirect restoration.
Soft, Type I alloys are used for casting inlays subject to slight stress during mastication.
Medium, Type II alloys can be used for practically all types of cast inlays and possibly posterior bridge abutments.
Hard, Type III alloys are acceptable for inlays, full crowns, three‑quarter crowns, and anterior or posterior bridge abutments.
Extra-hard, Type IV alloys are designed for cast-removable partial dentures.
Types of Casting Alloys
Ceramics are compounds that involve a combination of metallic and nonmetallic elements, creating strength and aesthetics.
Porcelain fused to metal (PFM)
Porcelain bonded to metal (PBM)
Porcelain-metal restorations (P-M)
Types of Ceramic Restorations
Type of ceramic that is most commonly used in dentistry. It combines strength, translucence and the ability to match the natural tooth color.
The shading of colors matches the tooth color well.
It esthetically improves the appearance of anterior teeth.
It has the strength of metal.
The material is a good insulator.
The material has a low coefficient of thermal expansion.