Flashcards in Operative Final Exam - Lectures: Basics, Instruments, and Class I Tooth Preps Deck (88)
What is the definition of caries?
the demineralization and subsequent cavitation of tooth structure
What is the goal of restorative dentistry?
carefully remove the diseased tissue (cavity) in a precise manner and replace the missing part with restorative material
What are the 3 most common areas in which cavities occur?
- occlusal pits and fissures of posterior teeth
- interproximal areas (between teeth below contact area)
- smooth surfaces of facial and lingual surfaces
Where is a Class I prep located?
pit and fissure preps
- occlusal surfaces of premolars and molars
- occlusal 2/3 of facial and lingual surfaces of molars
- lingual surfaces of maxillary incisors
Where is a Class II prep located?
proximal surfaces of posterior teeth
Where is a Class III prep located?
proximal surfaces of anterior teeth that do not include the incisal angle
Where is a Class IV prep located?
proximal surfaces of anterior teeth that include the incisal edge
Where is a Class V prep located?
the gingival third of the facial or lingual surfaces of all teeth
Where is a Class VI prep located?
on the incisal edges of anterior teeth or occlusal cusp tips of posterior teeth
What are the 3 types of powered cutting equipment?
- rotary (routinely used since 1960s)
- laser (recent FDA approval for preparing teeth)
- air abrasion
Which handpiece (high or slow speed) sprays water coolant to avoid tooth damage by heat?
Is a high speed handpiece angled or straight? A low speed handpiece?
- high speed - angled
- low speed - angled or straight
What metal makes up a bur?
carbide steel (stiff, strong, and brittle)
What are the 3 anatomical parts of a bur?
- head - cutting portion of bur
- neck - connects head to shank
- shank - part of the bur that inserts into instrument
What are the 5 shapes of a bur head?
- inverted cone
- straight fissure
- tapered fissure
How many flutes are found in a standard carbide bur? How many in a finishing carbide bur?
- 6 flutes in a standard
- 10, 12, 20, 30 in a finishing bur (more flutes = smoother finish)
What is the purpose of the shank of the bur?
controls the alignment and concentricity
What are the 3 types of shanks?
Of the 4 types of diamond grits for diamond burs (coarse, medium, fine, and very fine), which are the most efficient? Which are the least efficient?
- most efficient = coarse
- least efficient = very fine
What are the 2 cutting mechanisms of diamonds and burs?
- ductile fracture
- brittle fracture
Which type of fracture has deformation produced by shear forces?
Which type of fracture is associated with crack production from tensile loading?
Which type of cutting (bur or abrasive) is more efficient for cutting brittle materials like enamel?
Which type of cutting (bur or abrasive) is more efficient for cutting ductile materials like dentin?
bladed or bur cutting
What speed (high or low speed) is used for abrasive cutting?
What speed (high or low speed) is used for bladed or bur cutting?
high and low speed
What is a round bur used for?
- initial enamel penetration
- caries removal
- retentive grooves and holes
What is an inverted cone bur used for?
providing an undercut in a preparation
What is a straight fissure bur used for?
- straight walls
- flat floors