Restorative and Esthetic Dental Materials Flashcards
Introduction to restorative materials
restorative dental materials full-fill an important role in way dentists is delivered today.
It will be important to:
* Recognize available materials- not only in the treatment root, but also in office supply room.
- know how to dispense and mix these materials properly and perhaps apply some of them yourself.
- know how to properly clean the instruments used to prepare and place the materials and how to properly dispose of any leftover or expired materials.
Standardization of dental materials
American dental has criteria for new material. Those criteria state that the new material must meet the criteria listed:
- Not hurt the body or poisonous to the body.
- Not hurt tissues or cause oral cavity tissues to become inflamed
- Help protect teeth and oral tissues
-be similar in appearance to natural tooth structure. - be easy to apply in mouth
-conform to function
Type of stress and strain
- Tensile stress: materials is pulled and expanded.
-Compressive stress: materials is pushed into itself
-Shear stress: materials os broken down.
Example:
A patient has a habit of grinding her teeth at night? Shear stress
A patient reports clenching his teeth when he is concentrating had to work? Compressive stress
A patients enjoys eating sticky candy? Tensile stress
Mechanical properties
biting and chewing exert force in posterior of the mouth.
Force: strength or power exerted onto a materials.
Stress: manner in which the materials responds internally to force.
Strain: ultimate way in which materials way in which materials change because because of stress.
Thermal change
A temperature change occurs when a hot or cold material is introduced to the oral cavity. Because the makeup of dental materials differs from that of the oral cavity, materials change shape at their own rates.
Dental material can of the oral cavity, materials change shape at their own rates.
Dental materials can swell or shrink as a result of changes in temperature casing:
- Microleakage
-restoration failure
Electrical properties
Galvanic action to an electrical current that stems from two different metals being present in the oral cavity at the same time.
Galvanic action in the oral cavity can occure when the following are present:
- Saliva
- Two metallic components of different composition
Corrosive properties
when corrosive products come into contact with metal they can cause a reaction, including solubility.
common drinks or food have Corrosive properties? soft drinks, highly acidic soda, lemonade.
application properties
Sealants that help prevent decay can be placed on newly erupted permanent molars that are deeply fissured; however, the sealant material must flow well to plug up and protect area that are not easily to clean.
Several considerations with sealants:
- Flow: Dental material must be adaptable enough so that it can be placed as restoration.
- Adhesion: differing materials must adhere to each other. placing a piece of tap on a piece of paper.
-wetting: A materials must be able to flow over a surface. Hydrophilic (love water) and hydrophobic (hate water). Hydrophilic surface would not be wet well. by a hydrophobic liquid.
- viscosity: Higher the viscosity the less easily it will flow and the less it will wet the surface.
- surface characteristics: A liquid has an increased flow rate on a rough surface compared with that of a smooth surface.
- film thickness: The thinner the thickness of the film, the stronger the adhesive interface.
-Retention: two materials are being held together without the use of an adhesive material.
Curing
After the dental material is in the mouth, a setting process know as Curing is undertaken to allow the dental material to harden.
Auto-Curing: when a chemical reaction occurs within material resulting hardening of material.
Light Curing: when hardening of material results only when curing light is applies to material.
Restorative/Esthetic materials and restorations
function with pleasing esthetic.
esthetic: pleasing appearance, which to remake and gain a pleasing appearance.
Restorative materials need to be applied while material is adaptable and can be shaped to the tooth.
Materials used for restorative dentistry and esthetic procedures including:
- Amalgam
-composite restins - glass ionomers
- Intermediate restorative materials
- tooth whitening products.
There are vert distinct methods of dispensing, preparing, placing and finishing these materials. All are very technique sensitive and offer a wide range of treatment options.
The fist four materials about are placed in the mouth and adjusted to a desirable finish. They replace tooth structures that are missing as a results of cavity removal, fracture, or deficiency at the time of the appointment. Tooth-whitening system are example of esthetic restorative dentistry.
Dental Amalgam
used most frequently on posterior dentition. It is safe, cost effective and strong.
brought from France in 1832. Amalgam is an alloy which means made up of two or more different media.
Composed:
- Mercury: 43-54% of mixture.
-sliver: gives the amalgam strength.
-copper: provides strength and resistance to corrosion.
- Tine: provides workability and strength.
-Alloy powder: 46-57%.
-zinc: provides oxidation suppression.
Amalgam preparation
Amalgam must be prepared before application.
amalgam are available in
- 600 mgs of alloy
- 800 mgs of alloy.
Activator: equipment that is used to break the separating membrane membrane in the amalgam capsule.
The mercury and alloy are mixed each other to create amalgam in a process know as trituration. Be sure that trituration is complete before placing the amalgam in a carrier. Different manufacturers call for different trituration times, depending on the components of their products.
if the restoration involves a procimal surface , a matrix and wedge must be placed to reform the contour as necessary. The burnished is used at this step to burnish the metal where contact will be reestablished with the adjacent to tooth. slow speed handpiece.
Direct application of Amalgam is performed in a deries of steps
- Amalgam is mixed and transferred into an amalgam well
- Amalgam is transferred to the prepared tooth.
- Amalgam applied to tooth in increments
- increments are immediately condensed
- Anatomy is carved into amalgam with carvers
- Amalgam is smoothed with burnishers
- occlusion is checked
composite resine
used in restorative dentistry and esthetic procedures are composite resine.
composite resine: tooth colored restorative materials made of sillica or porcelain fillers; or other particles with liquid resin that bind together to form a solid and hard restoration materials.
Characteristics of composite resins:
- can withstand change in the environment of the oral cavity
- can easily be created to resemble the shape of natural dentition
- can be match to patient’s natural teeth
- can be directly bonded to the surface of the tooth.
Composition of composite Resine
To composite resin is a chemical mix. The mic including organic matrix, inorganic fillers, a coupling agent, and pigments.
The resin matric made of of
- Dimethacrylate (BIS-GMA) is fluid
- polymerization additives create a chemical reaction and allow the material to take shape
- Initiator
-Accelerator
-Retarder
- Ultraviolet (UV) stabilizers.
