Wear 1

Question 1

What are the types of tooth surface loss

Answer 1

Caries

Non-carious- wear, developmental disorders, trauma

Question 2

What is physiological tooth wear?

Answer 2

Normal wear that occurs due to normal function (increases with age- may not require treatment)

-> 20-38 um per annum

Question 3

What is pathological tooth wear?

Answer 3

Remaining tooth structure or pulpal health is compromised OR the rate of tooth wear is in excess of what would be expected for that age

->It can also be considered pathological if the patient experiences a masticatory or aesthetic deficit

Question 4

What are the causes of tooth wear?

Answer 4

Attrition

Abrasion

Erosion

Abfraction

Question 5

What is attrition?

Answer 5

The physiological wearing away of tooth structure as a result of tooth to tooth contact

Question 6

What are the features of attritive wear?

Answer 6

Found on occlusal and incisal surfaces

Appears as polished facets on cusps or flattening of tips

Gradually begins to cause shortened cusp/crown length and flattened occlusal planes

Question 7

What is the main cause of attritive wear?

Answer 7

Parafunctional habits- bruxism

Question 8

In attritive wear how do restorations wear in comparison to tooth tissue?

Answer 8

The same amount

Question 9

What is abrasion?

Answer 9

The physical wear of tooth substance through an abnormal mechanical process independent of occlusion (It involves a foreign object or substance repeatedly contacting the tooth)

Question 10

What is the site/pattern of abrasive tooth wear related to?

Answer 10

Where the abrasive object is used or applied

-> most common areas are labial and buccal regions (cervical on canines and premolars)

Question 11

How do abrasive lesions appear?

Answer 11

V-shaped or rounded
-> sharp line where enamel and dentine meet (scalloped appearance)

Notching on incised edges

Question 12

What are the causes of abrasive lesions?

Answer 12

Toothbrushing (most common)

Habits- biting pins, nails, electrical wire stripping, fishing line, thread, pipe smoking, ecigs

Question 13

Why may ecigs cause abrasive wear?

Answer 13

They are heavy and getting heavier

The liquid they use is acidic

Question 14

What is erosion?

Answer 14

The loss of tooth surface by a chemical process that does not involve bacterial action

-> most common wear and increasing in prevalance

Question 15

What typically causes erosion?

Answer 15

Exposure of teeth to acidic substance (can be intrinsic or extrinsic)

Question 16

What occurs in the early stages of erosion?

Answer 16

There is loss of surface detail, surfaces become flat and smooth

-> lesions appear concave and are usually bilateral

Question 17

How can erosion be differentiated from bacterial acid decalcification?

Answer 17

Lesions do not have chalky white appearance around margins

Question 18

What occurs in the later stages of erosion?

Answer 18

Dentine becomes exposed

Preferential wear of dentine leads to ‘cupping’ of the occlusal surfaces of the molars and incisal edges of the anteriors

Question 19

What is severity of erosion based on?

Answer 19

Source, type and frequency of exposure to the acid.

Question 20

How does erosion appear?

Answer 20

Cupping of teeth (deepest part does not contact opposing tooth)

Increased translucency of incisal edges (darkening)

No tooth staining (washed away by acid)

Rings of enamel around dentine

Restorations sitting proud of tooth

Question 21

What is abfraction?

Answer 21

The loss of hard tissue from eccentric occlusal forces leading to compressive and tensile stresses at the cervical fulcrum areas of the tooth

-> Typically appears as loss of tooth substance at cervical margin

Question 22

What causes abfraction? (theory)

Answer 22

Caused by biomechanical loading forces:

->Forces result in flexure and failure of the enamel and dentine at a location away from the loading
-> Disruption of the ordered crystalline structure of the enamel and dentine by cyclic fatigue (causing cracks and ‘chipping out’ of tooth substance)

Question 23

How does abfraction appear?

Answer 23

V shaped tooth loss (sharp) where the tooth is under tension
-> classically buccally at ACJ in premolars and molars

Question 24

What are the causes of cervical wear?

Answer 24

Multifactorial:

Overzealous toothbrushing

Combination of erosion, abrasion and abfraction

Question 25

What are the epidemiological issues with tooth wear?

Answer 25

Overall the incidence is increasing Difficult and Demanding to treat Expensive for the patient Expensive for the NHS

Question 26

What should be done when assessing tooth wear?

Answer 26

Recognise the problem is present Grade severity Diagnose the likely cause or causes Monitor the progression of the disease- is it active or historic?

Question 27

What do patients tend to complain about when they present with tooth wear?

Answer 27

Poor aesthetics Functional issues- poor masticatory efficiency, biting tongue/lips Pain- if rapidly progressing/pulpal involvement

Question 28

Why does wear tend not to cause pain?

Answer 28

In normal slowly progressing wear- secondary dentine is laid down and causes pulp to retreat further into tooth

Question 29

What aspects of a patients medical history could be related to or causing tooth wear?

Answer 29

Medications with low pH Medications which dry the mouth Eating Disorders Alcoholism Heartburn GORD (patient not always aware) Hiatus Hernia Rumination Pregnancy (reflux/morning sickness- transient) -> consider referral to GMP for treatment

Question 30

What aspects of a patients social history may be contributing to tooth wear?

Answer 30

Lifestyle stresses/occupation- Bruxism Alcohol consumption Diet Habits Sports- gels in endurance athletes

Question 31

What should be checked for in an EO examination when assessing the patient for tooth wear?

Answer 31

TMJ - restriction of movement, clicking, crepitus Examine musculature for hypertrophy Examine mouth opening for restriction (<4cm) and deviation during movement Parotid hypertrophy- bullimia Overclosure Lip Line Smile line

Question 32

What should be checked when examining the occlusion of a patient in a wear assessment?

Answer 32

Freeway space Record the OVD and resting face height -> Has their been dento-alveolar compensation Record overbite and overjet Stable contacts in centric relation/excursive movements

Question 33

Why may freeway space remain normal even in patient with excessive wear?

Answer 33

As wear is such a slow process:  Dentoalveolar compensation- bone grows down as teeth wears (takes teeth with it), incisal level stays similar

Question 34

What can dentoalveolar compensation due to wear result in?

Answer 34

Can result in different orthodontic relationships- can become more class III

Question 35

What can be done to treat wear in patients which is caused by excursive movement?

Answer 35

Give them canine guidance back (wear down composite rather than patient’s teeth)

Question 36

What other IO checks should be done in a wear assessment?

Answer 36

Soft Tissues- dryness, buccal keratosis or lingual scalloping Oral Hygiene Perio assessment BPE +/- pocket chart Dental charting

Question 37

What condition causes wear in the anterior and palatal regions?

Answer 37

Bullimia

Question 38

What does BEWE stand for?

Answer 38

Basic Erosive Wear Examination

Question 39

BEWE classification:

Answer 39

0= No erosive wear 1= Initial loss of surface texture 2= Distinct defect-hard tissue loss <50% of surface 3= Hard tissue loss >50% of the surface area

Question 40

What special tests may be useful when assessing tooth wear?

Answer 40

Sensibility testing- if wear may cause pulpal issues Radiographs Articulated study models Intra-oral photographs Salivary analysis Diagnostic Wax-up- show potential results of tx Dietary analysis