Managment of occlusal Caries

Question 1

Primary caries-

Answer 1

caries occurring on previously sound tooth surface

Question 2

Recurrent (secondary caries)-

Answer 2

primary caries occurring on margin of failing restoration

Question 3

Residual caries-

Answer 3

a portion of caries affected demineralised tissue left behind before a restoration is placed- intentionally or unintentional

Question 4

White spot lesion is due

Answer 4

to demineralisation of enamel crystals

Question 5

Why does the white spot lesion look different

Answer 5

As the surface and subsurface change progress, they affect the optical (light-handling) properties of the enamel. As a result, the surface of the affected area starts to lose its shine and glossiness, and overall the lesion begins to take on a lighter, chalky-white appearance. (Hence the name white spot lesion)

Question 6

Brown spot lesion

Answer 6

Repeated demineralisation and remineralisation can lead to pigment from blood/ food being incorporated into the enamel, this is then called a ‘brown spot lesion’

Question 7

Caries process:

To point lesion can be arrest

Answer 7

Arterial flow in the pulp increases
This causes an increase in the rate of flow of dentinal tubular fluid
The fluid acts to flush out bacterial toxins
It also carries antibacterial components (igG, lactoferrin etc)
Peritubular dentine gets laid down making the tubules narrower, this reduces the flow of the fluid ut also creating a barrier to the bacteria (sclerosis
Affected odontoblast produce tertiary dentine
At this stage the lesion can be arrested

Question 8

caries progression, If it contiunes to reversible pulpitis:

Answer 8

Further dentine is laid down to protect the pulp
Cavitation may occur due to undermined enamel
Caries start spreading laterally at ADJ
Affected (demineralised) dentine precedes infected dentine
When the caries get close to the pulp it become inflammed
There is a further increase in blood flow and pian and recptor A delta are activated
Reversible pulpitis
At this stage removal of the caries can allow the pulp to heal

Question 9

Caries progression, If it continues to irreversible pulpitis:

Answer 9

As bacteria approach the pulp level of inflammation becomes irreversible
Removing caries at this point may not preserve the vitality of the pulp but can relive painful toothache
(irreverisble pulpitis)

Question 10

Detection of occlusal caries

Answer 10

Examine wet and dry
Bite-wing radiographs- difficult to detect occlusal caries
Visual, tactile methods with the aid of probe/explorer
Dry tooth
Mineral demineralisation only visible on dry surface
Distinct enamel lesion visible under wet condition

Question 11

Prevention measures to promote ……

Restoration is destructive to tooth tissue…….

Answer 11

…..remineralisation

…..Replacement of restorations result in more tooth tissue loss weakening tooth

Question 12

Why is difficult to predict the rate of progression

Answer 12

The progress of caries through the enamel seems to be fairly slow but once the dentine is reached it accelerates
Small surface lesion may hide a much larger area of destruction below the surface

Question 13

Early smooth surface lesions are………..
Evidence suggests………….
Reminerlised tissue is………..

Answer 13

………… reversible in the right conditions
…………….that remineralisation can occur into dentine, if uncavitated
………….. less susceptible to further caries

Question 14

Caries management:

3 approaches

Answer 14

Biological approach
Conventional approach
Preventive management

Question 15

Management of caries depends on:

Answer 15

Is the tooth vital
Symptoms
Clinical appearance
Special tests
radiographs

Question 16

Biological managment

Answer 16

Therapeutic fissure seal- to inhibit progression of non-cavitated carious lesion
Sealing over caries- determine patients risk of disease progression
Low caries risk and the caries does NOT extend beyond the outer third of dentine
No cavitation/enamel breakdown
Record ICDAS code and discussion with patient
If the caries extend into the middle third of dentine a PRR is indicated

Question 17

Conventional caries managment

Answer 17

History/ assess extend of caries/ assess the pulp status/ how to preserve the pulp vitality during restoration- how much caries to remove? Pulp protection / avoiding puplal exposure

Question 18

Sensitivity test:

Answer 18

Not 100% reliable
Many false positive and false negatives
Electronic pulp test and ethyl chloride (cold) are the most likely tests
The number given by the EPT shouldn’t be inferred as meaning something (any number under 80 means probably alive, you can’t deduce the state of the pulp by the actual number)

Question 19

when diagnoising oclcusal caries discuss the use of bite wings and dental panoramics

Answer 19

Bite wings are good for diagnosing interproximal caries, but difficult in diagnosing occlusal caries
To evaluate the depth of a lesion which is developing occlusally, dental panoramic will give a greater diagnostic yield compared to BW radiogrpah

Question 20

What can you see in radiograph that affect caries managment

Answer 20

Radiograhs
Proximity to pulp/ lateral extent of caries/approximal enamel - affects how you store the tooth
May also be able to see: apical pathology/ widening of periodontal ligament space/ loss of lamina dura

Question 21

Caries on radiogrpahs image may only show-
how much deminerlisation must occure for radiogrpahic changes-
Deep caries that is as least 75% os the way to the puplp is ……

Answer 21

60-80 % of the actual caries present
Minmum of 55-60% demienrilsation must occur before radiographic changes are apperant
Caries will always be deeper and more extensive than you think
Deep caries is at least three quaters (75%) of the way to the pulp from the ADJ, so high risk of pulp exposure

Question 22

Sealing the cavity

Answer 22

Not all bacteria has to be removed
Selaed from oral enviroment
EDJ must be cleared of caries- provide good seal (& prevents any lateral spread of caries)
Consider carrying out a stepwise restoration

Question 23

Clinical procedures to avoid exposure

Answer 23

Partial caries removal
Stepwise- excavation
Principle ois that caries is removed until very near the pulp then stop- even if it is soft, fill the cavity with GIC, Re-valuate 6 months later and replace restoration if symptom free and still vital

Question 24

Optimize cavity for material choice

Answer 24

Make a final choice of material and modify the cavity to ensure optimum material success
Consider resistance and retention of restoration
Removed and unsupported enamel, ensure there are no weak edges that will fracture under occlusal loading
Remove any un-supporting enamel, ensure there are no weak edges that will fracture under occlusal loading
Make sure the margins are smooth, continuous and curving

Question 25

Maintaining pulp vitality

Answer 25

It is bacteria and dental operators that kill pulps
Aim of procedure is to remove caries without introducing any bacteria to the pulp
Use rubber dam
Remove caries from the walls of the cavity first
Never use a high speed for removing caries
On the floor of the cavity only use excavators, gently scrape away anything soft, never use force
Leave affected dentine over the pulp
Use RMGIC liner to seal affected dentine
Consider stepwise caries management

Question 26

High speed to gain access, when to use and how?

Answer 26

Gain access to the carious lesion

Cut back the walls of the cavity using the high speed handpiece just enough to permit you to gain access to the caries

Question 27

Clear the amelodentinal junction Part one:

Answer 27

Keeping the amelodentinal junction, use the slow speed handpiece and the largest bur that will fit into the carious lesion top remove the carious tissue
Leave the deeper caries over the pulp untouched
Using an excvator, check the texture of the dentine remaining at the amelodentinal junction

Question 28

Clear the amelodentinal junction part two:

Answer 28

If the dentine can’t be removed easily with the excavator go back to the slow speed handpiece
Repeat the cycle as often as necessary
If you need to cut back the margins a bit more for better access to the caries go back to the high speed handpiece

Question 29

Remove infected and leave affected dentine, consideration:

Answer 29

Think of the lesions as a spectrum
Use the slow speed, begin at the margins and work inwards towards the deepest part of the lesion
Stop frequently and use the excavator to checking the consistency of the dentine- use in raking motion
STOP either when you suspect that you are very close to the pulp chamber or when the dentine no longer furrows up

Question 30

When to stop removing dentine
Aim to remove….
May leave…..

The correct amount to remove ….

Answer 30

…..Dentine that contains bacteria ‘infected dentine’
……Softened dentine, demineralised by acid diffusing ahead of bacteria ‘ affected dentine’
…….is the minimum required to restore the tooth successfully and prevent disease progression

Question 31

Consider pulp protection, what’s its purpose?

Answer 31

Protect the pulp from bacterial infection and diffusion of bacterial acid and toxins
To seal and mechanically reinforce any layer of caries- affected dentine that may have been retained
To stimulate the dentine pulp complex to lay down tertiary dentine as a defence response
To protect the pulp from thermal, electrical and mechanical stimuli transmitted through the overlying restoration

Question 32

Ideal properties of pulp protection material

Answer 32

Bactericidal/ bacteriostatic
Mildly irritant to stimulate tertiary dentine bridge formation- high PH alkalinity
Adhesive- create effective seal
Low water solubility
Easily applied and strong in thin section
Ability to infiltrate ionically into remaining dentine overlying the pulp helping to provide reinforcement
biocompatible

Question 33

Pulp protection

Types and materials?

Answer 33

Material- glass ionomer cements, dentine bonding agents. Setting calcium hydroxide, tricalcium silicate cement (minerliased trioxide aggregate (MTA) biodentine
Indirect pulp cap- when the floor of the cavity is close to the pulp but the pulp chamber has not been breached
Direct pulp cap- if a small breach or pulp exposure has occurred

Question 34

Pulp exposure

3 main types

Answer 34

Iatrogenic- the dentist exposes the pulp during caries removal
Carious- caries has reached the pulp
Traumatic- trauma causes a fracture of the tooth involving the pulp

Question 35

Management of iatrogenic exposure

Answer 35

If tooth previously asymptomatic: rubber dam if not already, wash cavity, dry with cotton wool pledget (try to stop bleeding), then get tutor

Assess wheather the dentine around the exposure is carious of not, If carious- RCT is required

Assess the size of the exposure, if >2mm then RCT
If not place setting Ca(OH)2(Dycal)- calcium hydroxide over the exposure and dress the tooth with GIC
monitor

Question 36

Calcium Hydroxide- how does it work?

Answer 36

Very high (>pH11)
Creates an alkaline enviorment i.e bactericidal (highly toxic to bacteria)
Stimulates odontoblasts to lay down new reparative dentine in the dentinal tubules
Stimulates stem cells ion the pulp tissue to create new odontoblasts like cells to create dentine bridge across pulpal exposure

Question 37

Direct pulp capping is most successful when

Answer 37

Absence of signs of clinical symptoms of pulpitis before you start opening the tooth up
Normal response to vitality tests by the tooth
Younger patients without previous history of restorative work on the tooth in question
Tooth is isolated (rubber dam) and there is no salivary contamination
Small exposure <2mm in diameter
Exposure is not probed, or blown dry (damaging pulp tissue directly)

Question 38

Revision of tooth structure

Nerves

Answer 38

A delta nerves- Myelinated, fast response
Short sharp pain, tooth sensitivity, electric shock
C=Unmyelinated
Slow response time, dull throbbing ache