Non carious loss of mineralised dental tissue Flashcards
What are the 7 causes of tooth tissue loss?
- Trauma
- Caries
- Attrition
- Abrasion
- Erosion
- Abfraction
- Resoption
What is attrition?
Tooth to tooth frictional wear
What is abrasion?
Physical wear other than by tooth e.g. hair grips etc.
What is erosion?
Chemical non-bacterial dissolution
What is abfraction?
Flexing of the tooth = tensile or shear stresses weakening enamel prisms (microfractures)
What % of the population is affected by tooth wear?
97%
What % of the population have pathological degrees of tooth wear requiring treatment?
7%
What does the tooth wear index suggest?
The normal level of wear for each decade of life from 25 y/o
When does tooth wear become of significance?
When it becomes excessive, causing problems in function, aesthetics or sensitivity
What is the pH at which enamel prisms become looser?
pH 5.5 and below
Why should we brush teeth before breakfast or wait 30 mins after breakfast to brush?
Because acid in breakfast loosens enamel prisms = can knock off if brush after
What is extrinsic erosion?
Erosion from exogenous acids (related to occupation/diet) -> contributed to by: frequency, pH, saliva buffering capacity, method of consumption (e.g. swishing), time (night-time drinking) and temp
N.b…
Babies do not develop a taste for sweet or sour until they are given sweet or sour foods = if you can persuade parents to only give water and milk children will be happy with it
What is intrinsic erosion?
Erosion from endogenous acids (e.g. stomach acid) -> often seen in GORD, eating disorders, diabetes (reflux), GI ulcers, hiatus hernia etc.
Why are primary teeth more susceptible to caries/erosion?
Enamel and dentine is thinner, enamel is more porous (less mineralised) and lower phosphate
What is the clinical picture of attrition?
- Faceting of occlusal surface
- Wear similar between arches
- Pathology less frequent than erosion
- Dentine and enamel worn away equally
- Upper and lower teeth fit exactly perfectly
- Dentine and enamel equally worn away
- Depends on occlusal traits (if group function = multiple occlusal contact points)
What makes attrition worse?
Bruxism
Tell me more about bruxism:
- Greatest cause associated with anxiety
- Tooth faceting
- Up to 96% of population affected
- Cusp/restoration fracture
- Occlusal forces 39-60% normal biting (75kg)
- Associated with ecstasy and metamphetamine = posterior wear (jaw m. activity, bruxism, trismus, especially when associated w/ dry mouth)
What professions may your be more likely to see abrasion in?
Carpet layers, seamstresses and hairdressers (hold things between teeth)
What is the clinical presentation of toothbrush abrasion?
- Cervical (can be elsewhere too depending on site and hand used i.e.j if right handed scrub better on the left)
- Depends on the force of brushing, type of brush (electric or manual), bristle type and method of brushing
- Worse if brush just after acid insult (and quicker)
What is the clinical presentation of abrasion by restorative materials?
Wear on teeth opposing the restoration
Which restorative materials cause abrasion of enamel?
Porcelain, Nickel/chromium (although insult to enamel from clasps most likely due to caries due to plaque retention)
What is normal enamel/enamel wear?
20-40 micrometers per year
What other dental material can cause abrasion of enamel?
Dental floss if used wrong = v cut at cervical margin
