Toothwear I

Question 1

What is tooth wear?

Answer 1

The cumulative surface loss of mineralised tooth substance due to physical or chemo-physical processes (dental erosion, attrition, abrasion).

Tooth wear is not considered to be the result of dental caries, resorption, or trauma.

Erosive tooth wear is tooth wear with dental erosion as the primary aetiological factor.

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Question 2

What is attrition?

Answer 2

Physiologic loss of mineralised tooth substance due to tooth on tooth contact.

Question 3

What is abrasion?

Answer 3

Loss of mineralised tooth substance due to a third body coming into the mouth and wearing away the teeth (e.g. toothbrush, pen chewing, nail biting, etc).

Question 4

What is abfraction?

Answer 4

1. Pathologic loss of tooth structure thought to be from flexure during mastication
2. Wedge shaped defects to the cervical area (non-carious cervical lesions)

There was poor evidence that occlusal forces cause tooth wear and so it is thought that abfraction doesn’t really exist

Question 4

How prevalent is tooth wear in children?

Answer 4

1,308 children were examined in Birmingham at the age of 12 years and re-examined 2 years later

New or more advanced lesions were seen in 27% of the children over the study period

12% of erosion-free children at 12 years had developed the condition over the 2 years period

Question 5

How prevalent is tooth wear in adults?

Answer 5

77% of dentate patients have tooth wear into their dentine in their anterior teeth, 15% have moderate tooth wear and 2% have severe tooth wear (2009)

Roughly a third of all European adults aged 18-35 have one surface with moderate tooth wear, 3% have severe tooth wear (2013)

Question 6

Is toothwear prevalence increasing?

Answer 6

Yes, people are snacking more often, more soft drinks are being consumed, all of which can contribute to toothwear.

Question 7

Recap on enamel:

Answer 7

-96% mineral content = 3% water + 1% organic tissue

-Outer layer of enamel contains no prisms = aprismatic layer. It has highest mineral content containing fluoride and phosphate (fluorohydroxyapitite).

-Offers greatest protection against acid and mechanical challenges

Question 8

Recap on dentine:

Answer 8

-75% mineral, 20% organic material and 5% water

-Mantle dentine is close to enamel

-Mantle dentine similar to aprismatic layer with only a few curved tubules.

-Bulk of dentine = intertubular dentine (type I collagen rich structure) which has higher susceptibility to wear, such as abrasion.

-peritubular dentine is formed within the linen of tubules, it is highly mineralised making it more susceptible to acid challenge.

Question 9

What happen when teeth are exposed to an acidic environment?

Answer 9

-When teeth are exposed to an acidic environment, minerals are released from the surface causing softening of the outermost layer between 0.2 and 2µm thick.

-When acid encounters a natural enamel surface, there is initial breakdown of the interface between the prism and interprismatic layer widening the prism.

-Thereafter, the prism cores are richer in carbonate, making them more susceptible to erosion

-Liquid can move through enamel prisms of the teeth causing subsurface softening

-In the absence of further erosive challenges or mechanical removal, there is possibility for minerals to form new ionic bonds in the acid softened enamel

Question 10

Contrast the chemistry of caries with that of erosion.

Answer 10

Caries:
-Involves subsurface demineralisation
-Initial lesion has a small surface area
-Generally in protected areas with potential for localised application of remineralising agents
-Deep lesions
-Outer surface is generally harder due to fluoridation
-Increased oral hygiene results in decreased disease progression
-Plaque is a prerequisite

Erosion:
-Involves “softening” of surface enamel
-No protection from environment when demineralised
-Wide shallow lesions
-Outer surface is softest
-Increased oral hygiene may result in increased disease progression
-Occurs on plaque-free surfaces

Question 10

Caries vs erosive tooth wear

Answer 10

-main acid involved in caries = lactic acid present in the biofilm

-hydrochloric acid + citric acid = dental erosion

-Brushing helps improve caries but brushing can exacerbate erosive tooth wear

For both it is important to find all of the risk factors, examine diet and examine oral hygiene
look at slide

Question 11

How easily can dentine be removed compared to enamel?

Answer 11

Toothbrushing with a force of 400g has been shown to remove dentine and increase the number of patient dentine tubules so it is quite easily removed and this is even worse if it is acid softened dentine.

However with enamel, it would require very aggressive mechanical wear to remove it in the absence of an erosive challenge

Question 11

What is normal brushing force?

Answer 11

100-300g

Question 12

How might tooth wear be presented to you by the patient, what kinds of phrases might they use?

Answer 12

My teeth are short
My teeth have dips/crevices in them
My teeth keep chipping
My teeth are flat
My teeth are sensitive
My gums are shrinking away
My partner tells me I grind my teeth
I wake up in the morning with pain

Question 12

How can you identify erosion early?

Answer 12

Watch the maxillary central incisors and the lower first molars.

It usually occurs on clean, plaque-free surfaces.

Early stages can be difficult to distinguish with unworn teeth

As lesions progress, it becomes easier to identify but the tooth may be compromised

Question 13

What does early erosive tooth wear (ETW) look like in anterior teeth?

Answer 13

look at the slide

Question 14

What does severe ETW look like in anterior teeth?

Answer 14

-Prevention is sill effective and can stop restorative cycle
-Shortening
-Chipping
-Large Buccal lesions
-Smooth and glossy labial and Buccal surfaces

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Question 14

What does moderate ETW look like in posterior teeth?

Answer 14

-Cupping on occlusal surfaces
-Increasing exposure of yellow dentine
-Changes to shape of teeth
-Shortening of teeth

look at the slide

Question 14

What does moderate ETW look like in anterior teeth?

Answer 14

look at the slide

Question 15

What does early ETW look like in posterior teeth?

Answer 15

Loss of staining too

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Question 16

What does severe ETW look like in posterior teeth?

Answer 16

-Lesions start to merge
-Excessive dentine exposure
-Shortened clinical crowns
-Occlusal changes with alveolar compensation
-Prevention may slow progression and avoid the restorative/maintenance cycle

look at the slide

Question 17

What is the basic erosive wear exam (BEWE)?

Answer 17

-Simple tool to use alongside the BPE wherein you record the worse affected surface in the six sextants

-It’s quick and efficient

-Designed as a screening tool to alert the practitioner and patient and does not indicate need for restorative intervention

-It grades all tooth wear; not just erosion

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Question 18

What are the BEWE scores?

Answer 18

0-3

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Question 19

What are the management options depending on your patient’s cumulative BEWE score?

Answer 19

Add all the scores up across all sextants

A 3 in any sextant is HIGH risk

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Question 20

How would you clinically manage BEWE scores?

Answer 20

0-2 (primary prevention) : no risk, routine maintenance, 3 yr intervals.

3-8 (primary prevention) : OHI, dietary assessment, routine maintenance, review 2 yrs

9-13 (secondary prevention) : OHI, dietary advice, routine maintenance, fluoride measures, consider direct restorations, repeat 6-12 months.

14-18 (secondary + tertiary prevention) : referral to specialist prosthodontist, consider restorations.

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Question 21

Can BEWE be used in children? What do you need to take into considerations?

Answer 21

Yes, highest BEWE score in a sextant.

Primary dentition wears at a faster rate than the permanent dentition

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