caries symposium 2 + 3 Flashcards

1
Q

what are the 3 main things needed for caries to form

A
  • tooth
  • dental plaque
  • diet
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is a 4th factor that affects caries formation

A

time - how often is sugar consumed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what kind of patient can’t get any caries

A

edentulous patients as have no teeth for caries to from on

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

can baby’s get caries

A

yes

  • if fed with milk with lots of sugar
  • if mother has high caries diet then effects baby’s risk of caries too
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how is the enamel structure adapted to receive the first coat of proteins

A
  • first coating is coating that appears after brushing
  • is a protective lubricant to stop tooth from harming other soft tissues
  • when coating attaches to enamel it changes conformation (however bacteria have adapted to detect this change)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the secondary elements fro caries

A
  • perhaps more important than primary
  • saliva, capacity of buffering, presence of fluoride, diet etc
  • these elements drive caries
    secondary elements are also driven by external factors = social class, income, knowledge and education, attitudes and behaviour
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the definition of caries

A
  • demineralisation of tooth surface caused by acid produced by bacteria - acidogenic bacteria
  • breakdown of the balance between demineralisation and remineralisation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

does caries happen immediately

A

no, develops over a long time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how deep does caries go

A

as deep as it progresses

- has nothing to do with a hole, the hole is a consequence of caries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

can demineralised tissue be repaired

A
  • if repaired before cavity is there

- prevention is preferred = avoiding restorative procedures gives better quality of life for patient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how is a bigger lesion exposing the inside of the tooth better than a small lesion

A
  • small lesion may have caries growing underneath along the ADJ
  • an exposed lesion can still be brushed at least
  • can be restored without exposing the pulp
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what can affect how long a lesion will last

A

the environment in the mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the 4 parts of a white spot lesion

A
  • surface = 1% mineral loss (still intact)
  • body = 5% mineral loss
  • dark = 10% mineral loss
  • translucent = 20% mineral loss
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what promotes a white spot lesion

A
  • a succession of demineralisation and remineralisation
  • surface is remineralised first which is why it is less demineralised at the surface compared to the deeper enamel even though the plaque is on the surface
  • acid works better in subsurface of enamel than surface due to change in pKa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

why should you never probe a white spot lesion

A

it will likely create a cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the structure of a white spot lesion

A
  • subsurface is lost
  • enlarged gaps between rods = rods become thinner and rounder
  • rod length is preserved = crystallites running perpendicular to rod instead of parallel are less likely to demineralise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

does a white spot lesion from immediately

A

no

  • there is large time scale before cavitation
  • doesn’t happen immediately
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is a good way to allow patients to see how to clean their plaque off

A
  • use a staining chemical to allow them to see where the plaque is and then have them clean it
  • will give them a better understanding of how to clean properly
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is inter proximal caries

A
  • a lesion underneath the contact point

- plaque forms here so demineralisation occurs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

should you be worried about dark spots

A
  • no, should care about ‘active’ white spots

- the more active/demineralised the white spots are, the brighter more chalky white they become

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

how do you know the white spot is active

A
  • if the white spot lesion is not at the gingival margin then it is not active as plaque is at gingival margin
  • need mature plaque to produce acid - plaque that has been present for a long time
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what does an active white spot lesion look like under microscope

A
  • is quite rough

- has larger surface area for plaque to build up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what does an inactive white spot lesion look like

A

little loss of tissue - around 0.1mm

  • can’t restore even if you wanted to as lesion so small
  • it is not visible
24
Q

what must you do for inactive white spot lesions

A

need to protect it, clean it and give fluoride treatment to it

25
Q

how can you tell if patient is being non-compliant

A
  • if they come in with white spots along the gingival margin but no plaque there
  • shows they know what they are meant to do but don’t do it until they come to the dentist
  • shows patient wouldn’t take care of a restoration if given one
  • would need to see this patient more often = need to make them understand responsibility to look after their teeth
26
Q

what does it show if a patient has an inter proximal white spot lesion that is not at the gingival margin and with a missing neighbour tooth

A
  • used to have low compliance but now doesn’t
  • this gives a good opportunity to look at the mesial side and ensure it is intact and protected before neighbour tooth erupts as then have limited vision
27
Q

what can you do for patients with very tight contact points

A
  • put an orthodontic band between the teeth for a few days

- will create a space to work with

28
Q

what happens when a patient is exposed to sugar

A
  • the plaque pH decreases
  • how much it decreases depends on the maturity of the plaque
  • mature plaque means it has been there for a longer time and has infrastructure for protection = can reach lower pH
29
Q

how does mature plaque resist salivary buffering

A

the organic structure of plaque has matured enough to restrict the ability of buffering

30
Q

what are the 3 types of lesions

A
  • active carious lesions
  • inactive carious lesions
  • no visible lesion (sound tooth)
  • there is very little difference between inactive lesions and no visible lesion = all to do with diet
31
Q

what is the pH threshold for plaque to actively form

A

below pH 5.5

32
Q

how can you ‘beat’ caries

A

by increasing remineralisation and decreasing demineralisation

33
Q

how can you maintain pH

A
  • increase fluoride will make enamel stronger
  • reduce sugar intake = frequency
  • make environmental change
34
Q

what is the ecological shift that causes caries to form

A
  • mutans streptococci cause demineralisation
  • use sugar to produce energy, as a waste there is acid
  • survives well in acid = acidogenic
  • has a pump that keeps the inside fresh and alive by removing acid from its body = proteogluco pump
  • streptococcus sanguines causes remineralisation
  • proteolytic - destroys proteins
  • not associated with sugar and don’t like acid
35
Q

how can fluoride kill mutans streptococci

A

has ability to damage the proteogluco pump so will damage/kill the bacteria

36
Q

how can you make a patient less at risk of caries

A
  • dietary advice = change habits

- use fo fluoride toothpaste and varnishes

37
Q

what do you need to do if you spot a white lesion around a pit or fissure

A
  • don’t probe it, it will breach the enamel
  • need to try and identify the cavitation
  • as plaque receives sugar it produces acid, and buffering occurs more at surface regions which is why white spot lesions disappear more as you move away from pits and fissures
38
Q

what happens as you have acid production

A

there is demineralisation of the crystallites at the core central region - higher concentration of acid there

39
Q

what shape are pits and fissures lesions

A

triangle shaped

  • base of triangle is towards the dentine
  • lesion may be small at the surface but it will have more damage extending out underneath
40
Q

what happens when the lesion reaches dentine

A
  • spread very quickly
  • takes a long time to get there but once there is spreads very fast
  • dentine has tubules which branch out so once one is affected at ADJ the rest are soon after
41
Q

when does tertiary dentine form

A
  • once the lesion has reached dentine, tertiary dentine begins to form
  • dentine becomes sclerotic (hard) due to bacterial invasion
42
Q

what does it mean when there is a dark grey shadowing under the enamel

A
  • means the dentine has been breached
  • need to clean the tooth and polish
  • can see shadowing due to translucency of enamel
43
Q

which type of dentine is harder

A

sound dentine is harder than carious dentine

44
Q

what is the progression of a carious lesion in dentine from the ADJ to the pulp

A

area with bacterial invasion -> area with a lot of demineralisation -> area with a little demineralisation -> are a with hard dentine

45
Q

what is the most worrying looking lesion

A

when it looks wet and soft

- means it is the most active

46
Q

what is the least worrying looking lesion

A

when it looks hard and dark

  • means it has been there for a long time
  • looks the worst but is actually inactive caries (arrested caries) so is least worrying
47
Q

what is arrested caries

A

caries that is no longer active

48
Q

why is it difficult to restore the very active caries at the gingival margin of the tooth

A
  • usually when resting we use the surrounding material but don’t have a lot of that here
  • mainly just dentine there which is hard to work with
  • can restore with some sort of retention but it will likely just fall off
  • restoration here do more harm than good so just need to try and persuade patient to not have one
49
Q

where is there a higher concentration of fluoride

A

on the surface of a tooth

50
Q

why do we need demineralisation to happen to help remineralisation

A
  • fluoride is on enamel
  • need demineralisation of enamel as this will cause the deposition of hydroxyapatite form fluoride to bind to to from fluorapatite instead of HA = fluoride is stronger
51
Q

what happens to apatite over time

A
  • HA crystals get ion substitutions by Mg2+, CaO3 and Fl|-
  • structure changes over time
  • as apatite is converted, you lose areas of carbonated apatite
52
Q

do patients with a high concentration of calculus have high or low amount of caries

A
  • low amount
  • have a higher concentration of PO4 and a higher acid concentration so not suitable conditions for caries to form, just calculus
53
Q

what does caries show up as on a radiograph

A

grey shadowy areas

- dark/black areas on radiograph is not caries, these are spaces

54
Q

why are radiographs not perfect

A

they are 3D projections condensed into 2D images

- they should only be used as supporting elements

55
Q

how can changing the aspect of a radiograph help see caries

A

can help see the depth of the damage caused by caries