Biomaterials final review
Terms in this set (75)
Since 2005, the ADA seal of Acceptence is awarded to
consumer but not professional products
Dental materials considered devices as well as over the counter products sold to the public are subject to control and regulation of the ______ center for devices and radiological health.
Food and Drug administration
Which of the following represents the standards used to develop specifications and testing on an international level
ISO international standards organization
What is not a classification of dental materials...preventive, biological, restorative or therapeutic?
The first acceptable amalgam formula was developed by ______ in 1895
Normal masticatory forces on the occlusal surfaces of molar teeth can increase to as much as __llbs per square inch on a cusp tip
Stress is the amount of force exerted from within an object and ____________ is the amount of change that the force has produced.
Which material has the highest ultimate comprehensive strength?
The staining of resins and acrylics from repeated exposure to coffee tea and other dyed beverages is due to
This is term that allows the ingress of bacteria and oral fluids and may lead to recurrent caries staining an pulpal irritation
Which is the best thermal conductor?
The technique of chemical bonding rather than mechanical means to produce retention requires _________removal of tooth structure and produces a ____________retentive force between the tooth and the restoration.
Microleakage into the interface between tooth structure and restorative material is responsible for much of the _____________ observed following the tooth restortation
recurrent decay marginal staining and postoperative sensitivity
_______________ refers to the intensity or strength of the color
Microleakage is caused by
a poorly placed restoration, fracture in restoration, expansion and contraction of a restoration
What is not a concern regarding identification of dental materials in mouth
scaling could damage the surface of some materials.
Which type of bond occurs when two atoms share electrons in their outer shell
What has both shape and volume
What is the hardest material...cementum, enamel, compsite resin, cast gold
Enamel of tooth
The highter the viscosity the greater is a liquid's ability to resist flow. Usually, the viscosity of liquids increases as the temeratur increases.
The first statement is true second false
What is a direct restoration
Silver dental amalgam
________________ is the time permitted to manipulate the material in the mouth.
In general ___________temperature and __________humidity will accelerate the reaction of the material.
It is the responsibility of the ____- to assess the hazards of products produced by the chemical manufacture and pass this info to consumers
Exposure to chemicals over a prolonged period of time is _____________ exposure
The most commonly used etchant or conditioner for the tooth bonding is ___________in concentrations ranging from 10% to 38%
When a resin bonding agent hardens, it creates projections that lock into the tooth, creating a ____bond. The resin bonding agent will then form a ____bond to other resins placed over it such as a composite resin
The etched suface of a permanent tooth should have a _____appearance when dried
Microleakage occurs when
contaminants are not removed
Composite resins are composed mainly of an organic resin matrix and inorganic silica filler particles joined toghether by a ___________coupling agent
The fillers used in composite resins are
inorganic silica particles
The catalyst paste of a chemically cured composite resin contains _________ as an activatior
UDMA urethane dimethacrylate
The catalyst paste of a chemically cured composite resin contains _______ as an activatior
a tetiary amine
Flowable Composites are
useful as liners in large cavity preparations because they adapt to the preperation better than more viscous materials such as hybrid and packable composites
Which of the followin is true concerning polymerization shrinkage of composite resin restorations
Recent research indicates that the composite resin material does not shring toward the light
For composite restorative materials, the greater the filler content the _____ the coefficient of thermal expansion (CTE) and the greater the resin content the _____the CTE
Glass ionomers can be used as
restorations, cements and sealants
The organic matrix of composite resin is made up of
The accepted optimal level of fluoride in the drinking water is in the range of ______mg/L or parts per million
0.7 to 1.2
Flourides greatest anticaries benefit is gained from
topical flouride exposure after the teeth have erupted
What is true concerning in office flouride application
When used 1 to 2 times a year, topical flouride treatments have been shown to produce 20-26% caries reduction
What is true regarding a sports guard
They can cushion the maxillary and mandibular teeth when an athletes jaws are forced together by a blow to the lower jaw
What is true regaurding teeth bleaching
Teeth bleaching occurs when the bleaching material passes through the spaces in enamel and oxidizes stain
What is true reguarding types of tooth stains
In general, yellow-brown discolorations are easier to bleach than blue ray and black colors
Which is not a type of topical flouride application: flouridated toothpaste, 6 month in office application, daily mouth rinse, vitamin with flouride
vitamin with flouride
Which is most likely cause a sealant failure
moisture on the tooth
Which is not a cause of tooth sensitivity: exposed dentinal tubules, extreme hot and cold, craze lines in enamel, acidic foods?
Craze lines in enamel
The metals that are used as the core for the porcelain fused to metal crowns are alloys of specific metals that will form ______layer as the metal is heated.
The major drawback of all cermic restorations in the posterior of the mouth is the
A CAD/CAM machined crown uses an optical scanner to
take the impression
Insurance carriers have seen a reduction in the use of dental amalgam for posterior restorations by approximately 40% in the past 15 years probably because
concerns by patients about safety and its lack of esthetics have prompted many patients to request tooth colored materials
Modern dental amalgams are considered to be high ________in content compared with their predecessors.
It takes up to ______ for most amlgams to gain their maximum strength
What may happen if a newly placed amalgam contracts excessively
It will open gaps at the margins, contriute to leakage of fluids and bacteria and cause sensitivity
What is true regarding the strength of dental amalgam
amalgams are relatively weak in tension and shear and therefore require adequatebulk to resist breaking.
Polishing of amalgam restorations should be
wet with a light touch
increases the hardness of the alloy
Which is a noble metal used for dental casting alloys: silver, platinum, copper, titanium
Abrasive particles that are _____ will cut more efficiently
larger and irregular
The benefits of a properly finished and polished restoration/prosthesis include _____biofilm retention and ____resistance to tarnish and corrosion
When using hand instruments for margination, use very sharp instruments and begin ____the margin of the restoration, using a shaving motion in ___ overlapping strokes
apical ; diagonal
Staining at the margins of composite restorations due to microleakage
cannot be polished away
Air polishing utilizes a combination of ________, air, and water at a preasure of approximately 40psi as an effective and efficient means of removing stains and soft deposits from enamel surfaces
Prophylaxis toothpaste differes from over the counter toothpaste in that
it is more abrasive
What cement is used as a direct pulp capping agent when very small exposures of the pulp are suspected?
High strength bases placed in a thickness of 0.5mm or greater
provide protection from the thermal conduction of metal restorations
What cement has the highest in mechanical strength?
Which cements form a chemical bond to the tooth structure?
Zinc polycarboxylate and glass ionomer
What is not a reason to place a hight strength base
Promote reparative dentin
The completed impression forms a ____reproduction of the teeth and tissues and the replica or model forms a ____replica of the teeth and tissues
What is the most widely used dental impression material?
What is true for alginate hydrocolloid
some moisture will be lost from the impression even in 100% humidity
What elastomer is the most hydrophilic
Which material has the smallest dimensional change on setting of all elastomeric and hydrocolloid impression materials
What is an elastic impression material
vinyl polyether silicone