class 3, 4, 5

Question 1

what is a class 3 carrie?(4)

Answer 1

1. smooth surface caries which occur on the proximal surfaces of incisors and canines
2. Lesions generally begin gingival to the contact area (just like class 2) copycats!!!
3. may be detected radiographically, visually, or by transillumination (shine light behind anterior teeth - see decay)
4. incipent lesions v-shaped; deeper lesions spread laterally at the DEJ (dento-enamel juction)
   * class 1 base of 5 is at the occlusal surface

Question 2

what kind of prep is used for class 3?

Answer 2

classic preparation (utilize in simulation and for NERBS) - extend 0.5mm into dentin as does amalagam preparation

Question 3

4 important things to remember for class 3 are;?

Answer 3

1. clinic- modification of this preparation may allow you to finish the preparation on enamel without extending into dentin in some instances
2. proximity to the incisal edge frequently influences the shape of the final preparation
3. every attempt should be made to position the prep so that the incisal edge (corner) is not compromised
4. Shmulie Zafir owes his wife big time

Question 4

what are the 7 steps for class 3 preps?

Answer 4

1. outline form- outer shape of the prep and removal of decay
2. resistance form
3. retention form
4. access form
5. removal of decay
6. margination
7. debridement

Question 5

access entry appropriate for tooth conservation and aesthetics

Answer 5

outline form

Question 6

cavity margins terminate in sound tooth structure (doesnt cross marginal ridge!!) (form smooth continuous curve w/ no sharp angles)

Answer 6

outline form

Question 7

gingival cavosurface margin is free from contact with adjacent tooth. incisal margin contact which is NOT broken (unless undetermined by decay) ( contact broken gingivally only

Answer 7

outline form

Question 8

Lingual approach- used to retain as much intact facial “enamel” as possible

• initial entry is made gingival to contact area using # 330 bur
• bur enters tooth perpendicular to lingual surface

Answer 8

outline form

Question 9

classic prep- rectangular access

• prep is just gingival to the contact point
• remember where contact points are!
• maxillary anterior prep will be in the middle 1/3

Answer 9

outline form

Question 10

incisal and gingival walls are paralell, converging slightly towards the access (shape of the 330 bur) and face each other

Answer 10

outline form

Question 11

facial wall follows the facial contour of the tooth
*facial wall just barely extends out into facial embrasure for aesthetic reasons
*not necessary to break facial contact-
if broken, contact should be minimally opened to the point of “showing light” only
* facial enamel may be left unsupported ( unlike amalgam preps)

Answer 11

outline form

Question 12

begin just below the contact point

Answer 12

outline form

Question 13

facial approach may be preferred on mandibular incisors (use whichever approach is closest to lesion)

Answer 13

outline form

Question 14

what is resistance form?

Answer 14

internal shape that prevents fracture of filling or tooth

Question 15

axial wall is entirely in dentin about 1/2 mm

Answer 15

resistance form

Question 16

all caries and/or old restorative materials are removed

Answer 16

resistance form

Question 17

internal walls are smooth and well finished

Answer 17

resistance form

Question 18

preserve incisal angle

Answer 18

resistance form

Question 19

what is the axial depth fro resistance form?

Answer 19

1. 5 mm at the incisal
   - 1mm at the gingival
   - this allows you to have a prep which takes into account the thicker enamel in the incisal region
   - leaves axial wall 0.5 mm into dentin

Question 20

what is retention form?

Answer 20

internal shape that prevents filling from falling out

Question 21

no under cuts necessary

Answer 21

retention form

Question 22

acid-etch is method for…??

Answer 22

retention

Question 23

what is margination?

Answer 23

finishing of enamel

Question 24

• All cavosurface margins meeth the tooth surface at 90 degrees
• no bevels

Answer 24

margination

Question 25

what are the 12 steps to placing composites?

Answer 25

Placing Composites

1. Select shade (difference between anterior & posterior tooth – do first for anterior teeth)
2. Place rubber dam & prepare tooth
3. Pumice
4. Rinse
5. Air dry (do not desiccate)
6. Acid etch 15 sec (35% phosphoric acid)
7. Rinse
8. Air dry (do not desiccate)
9. Apply bonding agent (brush in)
10. Air dry slightly to remove solvent (no puddling)
11. Light cure
12. Place composite (cure only in 2mm increments)

Question 26

three finishing instrument are :?

Answer 26

1. sequential discs
2. diamond or fluted finishing burs
3. sandpaper strips

Question 27

how do you differentiate between different types of sequential discs?

Answer 27

they are color coated

Question 28

what are sand paper strips used for?

Answer 28

interproximal use

Question 29

what color box to sand paper strips come in?

Answer 29

blue/gray and red

Question 30

what should you be careful with regarding sand paper strips?

Answer 30

not to take away the contact point!!!