Week 1 Flashcards
In the late 1700’s what were invented
Porcelain teeth
In 1874 this was introduced as a means of preventative dentistry
Fluoridation
In 1901 who is credited with noting dental fluorosis in Colorado Springs
Dederick McKay
When was the first community water fluoridation program introduced
1945
The study of dental materials is the science covering the (6)
Evolution
Development
Properties
Manipulation
Care and evaluation
Of dental materials
What are the characteristic of dental materials (4)
-biocompatible
-bond permanently to tooth structure
-esthetically pleasing
-useful in repairing and regenerating missing tissues
Evidence based dentistry helps the clinician make decisions about
What is relevant to incorporate into practice
Developing an evidence based approach to addressing client concerns will
Increase the potential for successful client care outcomes by understanding the cause and effect relationship between biomaterials
There are 3 classifications of medical/dental devices grouped according to the amount of control needed to ensure their safety and efficacy
Class I: lowest risk; ex. Gloves, prophy paste, OTC PRODUCTS
Class II: products required to meet performance standards set by FDA or ADA. EX. Amalgam, composite
Class III: most regulated devices which sustain or support human life- require FDA approval. Ex. Bone grafting material, implants
Impression materials are used to make
Replicas of teeth restorations and preparations made for restorative treatments
An impression is a _____ reproduction of the oral structure
Negative
Diagnostic cast (study models) refers to
Positive replica of the teeth and surrounding oral tissue
Die refers to
The replica of a tooth that had been prepared for a restoration
3 types of impressions
Preliminary impressions
Final impressions
Bite registration
What are the 2 types of impression materials
Elastic materials (hydrocolloids, polyvinyl siloxane, polyether)
Inelastic materials (older impression materials rarely used; wax impression plaster, zinc oxide eugenol)
What are hydrocolloids
Water based colloids that function as elastic impression materials
2 types of hydrocolloids
Reversible
Irreversible
Sol refers to
Liquid state in which colloid particles are suspended
Gel refers to
Semisolid state in which colloid particles form a framework that traps liquid
Agar is what kind of hydrocolloid material? What is its composition?
Reversible
80% water, 8-15% agar
What is the most widely used impression material
Alginate hydrocolloid
Alginate hydrocolloid changes from
Sol phase to a gel phase via chemical reaction and it cannot be reversed
Alginate hydrocolloid is not accurate enough for final impressions, why?
Does not capture fine detail
Does not flow well into embrasures or occlusal surfaces
Alginate is
Elastic irreversible impression material made from seaweed
Advantages of irreversible hydrocolloid
Good for Subgingival impression
Working in a “wet” environment
Pouring models
Disadvantages of irreversible hydrocolloids
Shrinkage (syneresis)
Swelling (imbibition)
Poor tear strength
Client care- burning “tissues”
Using incorrect tray size when taking an impression will result
In an unacceptable impression
What may be used to extend the tray
Utility wax
Custom trays allow for
A more comfortable fit allowing for more accurate impressions
Triple trays allow clinician to take an impression of
Max mand and bite reg at the same time
Elastomeric materials are used (2)
-Where teeth are present and material flexibility is needed for removal from the oral cavity or teeth
- for impressions of preparations and for demanding highly accurate reproductions
Elastomeric materials have qualities similar to?
Composed of ?
Do they have different viscosities?
Have qualities similar to rubber
Composed of a base and an accelerator
Have different viscosities (putty, heavy, light bodied)
What is polysulfide
Oldest of the elastomers known as mercaptan rubber or rubber base
Polysulfide has an unpleasant
Taste, odor and stains clothing
Silicone material is available as
Additional reaction and condensation reaction
What should not be mixed with latex gloves on
Silicone putty
What is added to condensation silicone as a filler to keep the silicone paste from being runny and to provide stiffness
Silica or copper carbonate
What is the stiffest of all elastomers
Polyether
Most common method of displacing the gingival tissue away from the tooth prep to create space for impression material
Gingival retraction cord
Bleeding when using a retraction cord can be controlled by using (3)
LA with epinephrine
Astringent
Coagulation with laser or electrocautery
Advantages of digital impressions
No need for impression trays or materials
Images can be magnified, reviewed and retaken
More accurate
Disadvantages of digital impressions
Cost
Training/practice
Lab fees
Size of scanner
What does chroma refer to
Intensity or strength of the colour
*teeth are generally pale in colour
Value refers to
How light or dark the colour is; teeth have value ranges in light scale; they are determined by the way they reflect light
What does metamerism refer to
Colours look different under different light source
Bridge: what does retainer refer to
Part of bridge that fits over abutment
What is a Pontic
False or artificial tooth
What is abutment
Supporting natural tooth
Does an inlay involve cusp tips
No
What cavitron tip is the latest addition to the cavitron inserts designed for plaque and calculus removal around titanium implants and abutments
Cavitron softip ultrasonic implant insert
The cavitron softip implant insert is only used with a
Softip disposable prophy tip attached (single use item)
