Tooth wear

Question 1

what is erosion?

Answer 1

Loss of enamel and dentine primarily from chemical attack other than those chemicals produced intraorally by bacteria

Question 2

what is abrasion?

Answer 2

○ Physical wear by objects other than another tooth

Question 3

what is attrition?

Answer 3

○ Physical wear of one tooth surface against another with tooth tissue loss occurring on the contact surfaces

Question 4

how is erosion monitored?

Answer 4

BEWE score
basic erosive wear examination

Question 5

how is a BEWE score done?

Answer 5

split into sextants and scored

Highest score per sextant recorded and totalled

Question 6

what does a BEWE score of 0 mean?

Answer 6

no erosive tooth wear

Question 7

what does a BEWE score of 1 mean?

Answer 7

initial loss of surface texture

Question 8

what does a BEWE score of 2 mean?

Answer 8

distinct defect, hard tissue loss <50% of the surface area

Question 9

what does a BEWE score of 3 mean?

Answer 9

hard tissue loss >50% of the surface area

Question 10

if the total BEWE score is 2 or less what do you do?

Answer 10

routine maintenance and observation every 3 years

Question 11

if the total BEWE score is 3-8 what do you do?

Answer 11

OH and dietary assessment and advice, routine maintenance and observation every 2 years

Question 12

if the total BEWE score is 9-13 what do you do?

Answer 12

same as 3-8 plus

identify risk factors and develop strategies to eliminate them. Fluoride application, monitor with photographs, impressions etc. avoid restorations

Question 13

if the total BEWE score is 14 and over what do you do?

Answer 13

same as 9-13 plus
consider special care that may require restorations. Repeat every 6-12 months

Question 14

what is dentine hypersensitivity?

Answer 14

occurs when the enamel goes away exposing dentine underneath. The dentine underneath is a tubular structure so any liquids that is going into the mouth will cause movement of fluid in the dentinal tubules. This is picked up by nerves in the pulp leading to transient hot and cold sensitivity.

Question 15

what is the rim of confidence?

Answer 15

the enamel goes but there is a rim of enamel at the edge of the tooth
Aetiology: if you have a tubular structure, it has an outer layer of enamel and inner core of dentine. If you apply acid, it is going to erode the outer enamel, but if you apply it to one aspect of the tube then there will always be an edge of enamel

Question 16

what is submargination?

Answer 16

filling is higher up than the tooth as tooth has eroded around it but filling has not

Question 17

tooth exposure to acids comes from where?

Answer 17

diet and GIT

Question 18

describe the route acid has to take to reach the tooth substance

Answer 18

Acid diffuses from the plaque and pellicle upon the tooth surface. It then has to penetrate the protein or lipid coating of individual hydroxyapatite crystals that make up the enamel tooth substance

Question 19

is enamel or dentine more acid soluble?

Answer 19

dentine

Question 20

why is dentine more acid soluble?

Answer 20

the crystals in dentine are smaller than those in enamel

surface area per gram of dentine is much higher than in enamel

More carbonate in dentine than enamel

Question 21

what are the two modes of attack of an acid?

Answer 21

direct surface etching
surface softening

Question 22

what is direct surface etching

Answer 22

dissolve by combining with carbonate/phosphate ion

Question 23

what is surface softening?

Answer 23

Form a complex with calcium to remove calcium from the lattice

Question 24

Subsurface softening gives opportunity to repair and reverse the process by?

Answer 24

remineralisation

Question 25

regurgitation is generally associated with increased gastric volume and pressure. how does it differ from vomiting?

Answer 25

Lack of diaphragmatic muscular contraction
Relatively small quantity of material ejected

Question 26

what is rumination?

Answer 26

Gastric contents are regurgitated, chewed and re-swallowed

Question 27

where is most severe erosion found? why?

Answer 27

palatal surface of teeth as the tongue has an abrasive action on softened surface, rare to find erosion on lingual surfaces of lower incisors