Minimally Invasive Dentistry W5/6

Question 1

Why do Pit and Fissure Caries occur?

Answer 1

Plaque are cariogenic microbiota accumulate in pits and fissures. Can’t reach these areas with toothbrush.

Question 2

What are Pit and Fissure Sealants, and what are their four functions?

Answer 2

Low viscosity, plastic material that can flow into, conform and occlude pit and fissure system. Prevents dental caries.

1. Physical barrier- against food etc
2. Eliminate environment- against strep mutant and cariogenic bacteria.
3. Cleansibility- smooth surface, easy to clean for self-cleansing
4. Chemically releasing fluoride- mixed with GICS can act as fluoride reservoir

Question 3

How do you prep the tooth for Pit and Fissure Sealants?

Answer 3

Remove the pellicle/plaque via pumice, probe, bristles, prophy paste and air abrasion

Question 4

What are Glass Ionomer based Pit and Fissure Sealants?

Answer 4

Transitional sealant where moisture control isn’t possible. Have a low retention rate.
Are mixed with fluoride and made with glass and acrylic.

Question 5

What are the general steps in a pit and fissure sealant?

Answer 5

1. Pumice or prophy paste rinse and dry
2. Acid etch- 15 seconds of 35% phosphoric acid etch- rinse and dry
3. Place sealant material without trapping air
4. 20 second light cure for each sealant
5. Check the set, edges and occlusion

Question 6

What is minimally invasive dentistry and the 4 steps associated?

Answer 6

First occurrence, early detection, earliest cure of damaged/defective tooth on a microlevel. Followed by minimally invasive treatment to repair irreversible damage.
Recognise, rejuvenate, restore/repair and review

Question 7

What are the three types of non-carious damage to teeth?

Answer 7

Tooth wear, developmental defects and trauma

Question 8

Identify the 4 types of tooth wear

Answer 8

Attrition- Tooth to tooth contact
Abrasion- Tooth to non-tooth contact (friction)
Abfraction- cervical V shaped enamel-dentine defects (idiopathic- no history of abrasion) due to masticatory stress.
Erosion- chemical process acid attack

Question 9

What are the two sources of acid erosion?

Answer 9

• Intrinsic acid- gastric acid. Voluntary (induced vomitting) or involuntary
• Extrinsic acid- dietary or environmental fumes

Question 10

What are the three types of mechanical wear to teeth?

Answer 10

Attrition: tooth to tooth contact

Abrasion: tooth to non-tooth contact

Abfraction: cervical V shaped wear of enamel-dentin due to masticatory stress

Question 11

What are examples of hereditary and non-hereditary developmental defects?

Answer 11

• Hereditary- affects all teeth: ameleogenisis imperfecta or dentinogenesis imperfecta
• Non-hereditary- hypoplasia (enamel defect) or hypo mineralisation (lack of mineral content in enamel)

Question 12

Define caries

Answer 12

Preventable, chronic and biofilm mediated disease modulated by diet.

A multifactorial oral disease caused by imbalance of oral flora (biofilm) and high fermentable carbs on the tooth surface over time.

Influenced by a shift in the equilibrium of protective vs pathological factors

Question 13

What five ways can caries be described by?

Answer 13

1. Location- pit and fissure, root, or smooth surface
2. Direction of Progression
3. Zone- enamel, CEJ or dentine
4. Extent - incipient vs cavitated
5. Progression rate- acute or arrested

Question 14

What are the four factors necessary for caries to occur?

Answer 14

1. Susceptible host
2. Cariogenic bacteria
3. Fermentable carbs
4. Time

Question 15

What is the net demineralisation for dental hard tissue damage to occur?

Answer 15

Critical pH of 5.5

Question 16

What is plaque, and what are the three sites where plaque forms?

Answer 16

Firmly adherent microbial biofilm attached to surface of teeth and is the prime agent of dental caries.

Margins, fissures and interproximal areas

Question 17

What is the difference between rampant caries and arrested caries?

Answer 17

• Rampant: acute, accelerating caries progression- multiple carious lesions i.e. high carb diet, drugs
• Arrested: chronic, inactive lesions- enamel white spot lesions

Question 18

Can arrested dentine caries be reversed? Why?

Answer 18

no- because destruction of collagen matrix has began

Question 19

Identify enamel caries vs CEJ caries?

Answer 19

• Enamel: subsurface demin causes White Spot Lesions- which are initially smooth and opaque.
• CEJ: lesions extend laterally and then penetrate dentinal tubules

Question 20

What are white spot lesions?

Answer 20

Subsurface demin that causes Enamel prism porosities

Question 21

Once caries is in dentine, how is it recognised visually?

What are the three types of caries in dentine?

Answer 21

Tooth goes greyish colour.

• Soft: outer carious dentin soft and infected
• Firm: intertubular dentine
• Hard: tertiary, sclerotic dentine

Question 22

Give an example of caries classification system used

Answer 22

ICDAS

Question 23

What are the visual methods of detecting caries?

Answer 23

Using mirror and probe, loupes , caries detecting dyes

Then X-rays

Question 24

What are some factors that increase risk in caries?

Answer 24

Diet, medical history, saliva, dental work, plaque control

Question 25

What are the non-invasive and prevention treatment modalities for caries?

Answer 25

• Fluoride
• CPP-ACP
• Xylitol
• Dental ozone

Question 26

When would you use dental ozone and what type of modality is it?

Answer 26

Primary root caries, pit and fissure carious lesions.

Non-invasive, natural, uses 2200ppm to kill 99% of microbial bacteria and oxidises caries and speeds up remineralisation

Question 27

Engine and turbine rotary instruments are used in operative treatment and are invasive. What is an example modality?

Answer 27

air abrasion, hard tissue laser, chemo-mechanical removal.

Question 28

What is Stephan’s Curve?

Answer 28

• Depicts the sudden decrease in plaque pH after glucose rise.
• Returns to normal after 30-60 minutes.
• Hard tissues demineralise below critical 5.5 pH
• Mature plaque metabolises and uses fermentable carbs = acidic environment