toothwear 2

Question 1

what is a popular type of splint used for treating attrition

Answer 1

michigan hard splint
has canine rises which discludes other teeth during lateral movements

Question 2

how long should passive management of dental wear be done for

Answer 2

at least 6 months
involves prevention and monitoring

Question 3

what 5 factors does active management of toothwear depend on

Answer 3

• pattern of toothwear
• inter occlusal space
• space required for restorations being planned
• quality and quantity of remaining tooth tissue (particularly enamel)
• aesthetic demands of patient

Question 4

what are the 3 categories of maxillary incisor toothwear

Answer 4

toothwear limited to the palatal surfaces only
toothwear involving the palatal and incisal edges with reduced clinical crown height
toothwear limited to labial surfaces (rare)

Question 5

what is the favoured method in gaining space in cases of localised anterior tooth wear

Answer 5

dahl technique

Question 6

describe the dahl technique

Answer 6

either a bite platform or composites should be used to create inter occlusal space anteriorly
Results in posterior disclusion and an increase in OVD of around 2-3mm
Over period of 3-6 months space is gained between incisor teeth and the posteriors erupt

Question 7

what thickness of composite must be used to prevent early failure

Answer 7

at least 2mm

Question 8

contraindications to composite build ups for anterior toothwear

Answer 8

short roots
reduced periodontal support
lack of enamel - reduced success rate

Question 9

‘ring of confidence’

Answer 9

enamel around entirety of area placing composite
much better success if this is present

Question 10

why is lower anterior toothwear more difficult to fix

Answer 10

less enamel therefore smaller bonding area
moisture control is much harder

Question 11

localised posterior toothwear is rare, what patients may it be seen in

Answer 11

ruminating patients

Question 12

name the 2 methods of composite build ups (using ‘templates’)

Answer 12

1. putty matrix - alginate impression, wax up, putty matrix
2. vaccum splint - alginate impression, wax up, stone cast, clear vaccum matrix

Question 13

if doing build ups for a patient what post op ‘instructions’ should they be given about their new bite

Answer 13

• may feel strange for a few days but should become accustomed to it within about a week
• may have difficulty chewing initially until bite settles
• may notice a lisp for the first few days
• may find yourself biting lip and tongue initially
• longevity should be good but there is risk of debonding and lifelong maintenane is required

Question 16

who proposed the shortened dental arch concept

Answer 16

Kayser 1981

Question 17

what is the shortened dental arch concept

Answer 17

a dentition where most posterior teeth are missing
Patient has satisfactory oral function without use of RPD

Question 18

in regards to the shortened dental arch concept , how may occlusal unit must a patient have to have sufficient adaptive capacity

Answer 18

3-5 occlusal units
occluding pre molars = 1 unit
occluding molars = 2 units

Question 19

indications for shortened dental arch

Answer 19

missing posterior teeth with 3-5 occlusal units remaining
favourable prognosis for remaining anterior and pre molar teeth
patient not otivated to pursue a complicated treatment plan
limited financial resources for dental care

Question 20

contraindications for shortened dental arch

Answer 20

poor prognosis for remaining dentition
untreated or advanced periodontal disease
pre existing TMJ dysfunction
signs of pathological toothwear
significant malocclusion (wont have anything to bite together)

Question 21

why is SDA not appropriate for patients with severe or untreated periodontal disease

Answer 21

• periodontally compromised teeth may drift under occlusal load
• distal tooth migration, which occurs in SDA, is exacerbated by inadequate periodontal support
• loss of alveolar bone leading to compromised denture bearing area should it be required in the future

Question 22

why is pathological toothwear a contraindication of SDA

Answer 22

compromises long term survival of teeth
will see gradual loss of occlusal contacts and occlusal stability

Question 23

what is occlusal stability

Answer 23

the stability of tooth positioning relative to its spatial relationship in the occluding dental arches

Question 24

what are the 5 requirements of occlusal stability

Answer 24

stable contacts on all teeth of equal intensity in centric occlusion
anterior guidance in harmony with envelope of function
disclusion of all posterior teeth during mandibular protrusive movement
disclusion of posterior teeth on non working side during mandibular lateral movement
disclusion of posterior teeth on working side during mandibular lateral movement

Question 25

combination syndrome

Answer 25

flimsy evidence on whether actually exists
natural teeth opposed by a complete denture
may cause instability in complete denture function
occlusal forces may be concentrated in anterior section of complete denture - risk of flabby ridge