approx caries, FVC, Occlusion(NON IMAGES-USE IPAD)

Question 1

what are class VI lesions, where do they usually occur?

Answer 1

usually in developmental defects in enamel formation, could be called pit caries

• can also occur in older people on cusp tips where enamel has worn away.
• both of these are pretty uncommon

Question 2

what is the most common and first to develop in secondary dentition (type of caries(

Answer 2

class I

Question 3

when is class II common/

Answer 3

pediatrics/primary teeth

Question 4

what is class V caries? why does it occur ?

Answer 4

smooth surface caries! Between height of contour and the CEJ
-until middle age, CEJ is covered by periodontal tissues- very resistant to caries. between gumline and height of contour, enamel is not naturally cleaned by the cheek/lip/tongue movement- allows accumulation of plaque for long periods of time. if tooth brushing is ineffective will get whitespot-caries

Question 5

what is root caries, how is it classified? is it easy to determine?

Answer 5

apical to the CEJ- can be considered a class V caries lesion. 
-easy to determine if class V enamel or root caries, but proximally it can be hard to say where CEJ is located *remember margins are at dentin or cementum, so this means different materials need to be used

Question 6

approximal caries vs proximal root caries?

Answer 6

at normal enamel to enamel contact, not proximal root caries.

• if there is root caries on proximal root surfaces, it might need to be handled like approximal caries but in younger patients approximal caries is just when enamel meets enamel. (not exactly at that point but slightly gingival)
• may get root caries with a 2nd molar root and crown of wisdom tooth

(approxixmal= class II caries!)

Question 7

how does approximal caries form? where is it located and what is the shape

Answer 7

from gingiva to contact- its undisturbed plaque on smooth surface of tooth. Limited by gingiva (wont occur when that starts)

• contact area is plaque free as well. so its gingival to contact
• shape of lesion is approximately a horizontal oval!

Question 8

where are class II caries easily hidden

Answer 8

in the posterior teeth when early. the bulk of the posterior teeth hide it well. Class III (approximal anterior) is easier to see even before radiographic evidence

Question 9

how does approximal caries compare to class I lesions with regards to dentin involvement

Answer 9

approximal caries has more enamel to go through to get to the dentin!! no portals through enamel like in class I with the pits and fissures

Question 10

how should you diagnose a class II caries

Answer 10

DO NOT check physically with an explorer, you can’t tell. diagnosed with X RAYS - bitewing are most accurate for approximal lesions

Question 11

how will approximal remineralized enamel appear on a radiograph

Answer 11

it will not return to normal translucency, may be deeply stained but it will have good resistance to loss of mineral , due to higher fluoride content (bc of pores I think?)

Question 12

what is a general rule about self cleansing and the contact area location?

Answer 12

self cleansing increases with distance from the contact area, EXCEPTION is gingival embrasures

Question 13

what is E1?

Answer 13

-outer half of enamel

enamel is superficially demineralied and there are NO changes in dentin

Question 14

what is E2?

Answer 14

acids begin to affect underlying dentin, some los sof mineral directly subjacent to the demineralized enamel. Maybe some discoloration from stain, especially in slower lesions. No spread of demineralization along the DEJ.
-inner half of enamel

Question 15

What is D1 caries?

Answer 15

enamel begun to break down/cavitate. bacteria can now occupy space left by demineralized dentin , can get through the enamel to it. May be substantial staining in dentin, leading all the way to the pulp but the actual destruction of dentin is more superficial. starts to go along dej.

Question 16

What is D2 caries?

Answer 16

FRANK cavity = tooth has oval chalkiness and some shadowing. unsupported enamel broke away, reveals soft dentin. D2 lesion indicates demineralization, and radiolucency, extending into the MIDDLE THIRD of the dentin. extensive destruction of dentin occlusally, gingivally, bucally and lingually, and axially (circumferential)
-pulp MAY be involved

Question 17

what is D3 caries?

Answer 17

lucency and demin into INNER THIRD of dentin. Pulp involvement is likely, and circumferential destruction of dentin and undermining of enamel is extensive, repair with direct restoration like a filling would be difficult/unreliable. Apical destruction can make the tooth unrestorable! (maybe bc a crown wouldnt work anymore?)

Question 18

what is wrong with a periapical radiograph for diagnosing approximal caries?

Answer 18

Angle of x ray beam is usually too high or low to highlight the horizontally oriented oval lesion.

Question 19

which type of radiograph is best for alveolar bone height? what else is it good for

Answer 19

bitewings!

-approximal caries!

Question 20

what does E0 mean

Answer 20

no visible change

Question 21

how is E2 lesion treated

Answer 21

discretion of dentist, taking into account patient risk of caries

Question 22

how is D1 treated

Answer 22

most dentists would treat the lesion in any patient with moderate to high caries risk

Question 23

when is a tooth difficult/impossible to restore?

Answer 23

at D3 stage it may enter into root area, apical demineralization can make it impossible to restore

Question 24

why does malocclusion lead to impediments in interpretation of radiographs, what else can?

Answer 24

overlaps of teeth gives us no info on that area. Can also occur from poorly orietned x ray beams as well as crooked teeth.

• also restorations , amalgam of one tooth can overlap the other tooth and its more radiopaque.
• also OPTICAL ILLUSIONS

Question 25

what are the optical illusions to look out for on radiographs

Answer 25

• contrast: can be fooled by contrasts between structures, bright objects make surroundings seem darker
• cervical burnout : apical to CEJ on proximal surfaces. Looks diff from approximal caries because no change in enamel is visible, but dentin looks dark. Root caries needs to be ruled out. root concavities contribute.
• calculus: can fool us if it shows up apical to the CEJ, looks more like root caries than approximal caries too.

Question 26

how should the x ray beam be angled against the lesion (approximal caries)

Answer 26

It should be PARALLEL to the long axis of oval defect. Then visible. If its not parallel to the long axis of the oval defect, seen as no radiolucency at all (attenuation of beam is less well defined?) maybe seeing obvious lesion in dentin but not enamel - it is there!

Question 27

how to prevent approximal caries?

Answer 27

• tooth brushing for lingual/buccal extensions
• flossing
• fluoride. all delivery methods
• diamine fluoride (harsh!! long exposure, hospitals i think)

Question 28

overall is it easier to see enamel or dentin defects?

Answer 28

enamel!! more clear and defined.

Question 29

when do we do crowns?

Answer 29

• gross caries
• trauma
• wear
• large existing restoration

Question 30

what are the PROS and CONS of FVC crowns?

Answer 30

full veneer crowns 
Pros: 
-longevity
-excellent axial contours
-conservative occlusal and axial prep 

Cons:

• esthetics
• material cost
• aggressive prep (compared to fillings)

Question 31

what are the SEVEN principles of a crown preparation?

Answer 31

• conservation of tooth structure (dont weaken unnecesssarily or impinge on pulp)
• retention form (prevent displacement of cemented restoration along path of insertion)
• resistance form (prevent dislodgement of cemented restoration by apical or oblique directed forces
• structural durability: (give enough space for a crown, which is sufficiently thick to prevent fracture, distort or perforate)
• marginal integrity (margin/finish line to accommodate a robust margin with close adatation to minimize micro leakage)
• preservation of periodontium (do not over contour /make bulky crowns to prevent cleansibility)
• aesthetics (may need to create enough reduction on tooth aesthetic materials)

Question 32

what goes into ensuring conservation of tooth structure for fvc?

Answer 32

• remove enough tooth structure for material strength and optimal contours
• remove all caries/decay
• stay above gingiva- accessable/cleansible
• avoid vital pulp

Question 33

what is retention form- 5 things it depends on? what is more common than this as a failure?

Answer 33

quality of prep- prevents dislodgement from forces parallel to path of placement. Only dentl caries and porcelain fracture cause more failure of crowns than a lack of retention!!!!!

1. stickiness goes up, dislodgement magnitude force goes up
2. roughness of fitting surface of the restoration
3. materials being cemented
4. film thickness and properties of luting agents
5. Geometry of tooth preparation

Question 34

what is the function of the temporal muscle

Answer 34

elevates and retracts mandible, assists rotation, clenching

Question 35

what is the function of the masseter?

Answer 35

elevates and protracts mandible, assists in lateral movement, active in clenching

Question 36

what is the function of medial pterygoid

Answer 36

elevates mandible, enables lateral movement and protrusion

Question 37

what is the function of the superior lateral pterygoid

Answer 37

positions articular disk in closing

Question 38

what is the function of inferior lateral pterygoid

Answer 38

protrudes and depresses mandible, enables lateral movement

Question 39

function of mylohyoid muscle

Answer 39

elevates and stabilizes hyoid bone

Question 40

function of geniohyoid?

Answer 40

elevates and draws hyoid bone forward

Question 41

function of anterior belly of digastric muscle

Answer 41

elevates hyoid bone, depresses mandible

Question 42

where is the condylar process when mandible/maxilla teeth are touching in ideal occclusion

Answer 42

its fully seated in the mandibular fossa

Question 43

in the seated position of condyyle-articular disk assembly- how should max and mandible teeth appear
how is it often instead

Answer 43

MAX intercuspation!

in many patients, maximal intercuspal contact occurs with the condyles in a slightly translated position (?)

Question 44

what is centric relation?

Answer 44

maxillomandibular relationship where condyles articulate with the thinnest avascular portion of their respective articular disks , with the complex in the anterosuperior position against the shapes of the articular eminences.

independent of tooth contact!! slide 23

Question 45

what is maximum intercuspation

Answer 45

complete intercuspation (interdigitation) of the opposing teeth, independent of condylar positiion, this is sometimes considered the best fit of the teeth regardless of condylar position. 
-maxillary lingual and mandibular buccal cusps of posterior teeth are evently distributed and in stable contact with opposing occlusal fossae.

Question 46

what are border movements?

Answer 46

pure rotation and translatory movement (of mandible)

translation - all points within body have identical movement and rotation: all moving along ais

Question 47

know: protrusion, mediotrusion, laterotrusion, lateroprotrusion

Answer 47

slide 27

Question 48

what is the pocket fence representing

Answer 48

cusps to marginal ridges “tooth to two teeth”

Question 49

which teeth have only 1 opposing tooth

Answer 49

mandibular central incisors

Question 50

what is angle class I canine and molar relationship

Answer 50

most common

mandibular canine fits IN embrasure between maxillary canine and lateral incisor!
mesiobuccal cusp of maxillary first molar over buccal groove of mandibular first molar

Question 51

what is angle class II canine molar relation

Answer 51

mandibular canine fits POSTERIOR to embrasure b/w maxillary canine and lateral incisor
buccal groove of mandibular molar is posterior to mesiobuccal cusp of maxillary first molar

Question 52

what is angle class III canine molar relation

Answer 52

least common

mandibular canine fits ANTERIOR to embrasure between maxillary canine and lateral incisor. Buccal groove of mandibular molar is ANTERIOR to mesiobuccal cusp of maxillary first molar.

Question 53

what is cusp marginal ridge occlusion called and cusp fossa occlusion

Answer 53

cusp marginal ridge: tooth to two teeth

cusp fossa occlusion: tooth to tooth

-cusp marginal ridge found in nation, cusp fossa in some restored dentition

Question 54

what type of occlusion scheme is cusp to marginal ridge

Answer 54

cusp to marginal ridge

Question 55

what occurs in the initial phase of jaw opening- condyle vs disk and which muscle?

Answer 55

condyle makes a rotational movement with a small translational component, changing its position relative to the fossa only slightly. because of the condylar rotation, the disk moves posteriorly relative to the condyle. The only part of the lateral pterygoid muscle that is active is its LOWER head!!
-elastic fibers brought out of equilibrium minimally

Question 56

what occurs during intermediate phase of jaw opening

Answer 56

the condyle executes a definite translation. disk moves anteriorly relative to the fossa but posteriorly in relation to the condyle. tension becomes increaesd in superior stratum of bilaminar zone and in anterior wall of joint capsule. Inferior stratum relaxes to the same extent. Venous plexus expands creating negative pressure and fills with blood

Question 57

what occurs in the terminal phase of jaw opening

Answer 57

condyle reaches maximum extent of its rotation and translation. the translational component passively moves the disk farther forward while the rotation makes it lie farther posteriorly on the condyle. the superior stratum and lower anterior capsule wall are now stretched to maximum. The retrocondylar space is filled by blood flowing into genu vasculosum. inferior stratum is relaxed.

Question 58

what occurs in the initial phase of jaw closing

Answer 58

upper head of lateral pterygoid muscle retards distal movement of the condyle through eccentric muscle activity. the disk can only be passively guided poteriorly. in the initial phase this is brought out by tension in elastic superior stratum.

Question 59

what occurs in intermediate phase of jaw closing

Answer 59

upper head of lateral pterygoid further stabilizes condyle on the articular protuberance. tension in the superior stratum steadily diminishes, and the disk because of the bulge of its pars posterior, is passively carried further distally.
nonphysiologicla increase of pressure in genu vasculosum due to sympathetic or hormonal influences would exert an anteriorly directed force on the disk .
-this can lead to increased tension in the inferior stratum and fltattening of the disk

Question 60

what happens in the terminal phase of jaw closing

Answer 60

once jaws are closed the elastic structures are relaxed again. The inferior stratum becomes increasingly tense and finally prevents anterior disk displacement in case the condyle moves too far distally.
Anterior disk displacement can occur only in the presence of an ovserstretched inferior stratum, with or without flattening of the pars posterior

Question 61

what does a 1, steeper, 2. flatter inclination of articular eminence result in

Answer 61

1. posterior cusps may be taller

2. posterior cusps may be shorter