Special Investigations

Question 1

what are some examples of special investigations?

Answer 1

• vitality tests
• radiographs
• blood tests
• bacteriological/viral swabs
• biopsy etc

Question 2

vitality test: carried out with what equipment? what substance is used for cold/heat testing?

Answer 2

• electric pulp tester
• cold: ethyl chloride
• heat: gutta percha

Question 3

blood tests: when are they taken?

Answer 3

• prior to GA if anemia suspected
• autoimmune disorders
• hormone imbalance (thyroid, insulin)
• bone disorders - calcium levels

Question 4

bacterial & viral swabs:
when taken?
how is a sample acquired?

Answer 4

• prior to prescribing antibiotics: correct choice of drug?
• sample of pus, fluid exudate or fluid from a blister collected
• blood culture

Question 5

biopsy: how is it taken? how is the sample examined? what is an excisional/incisional biopsy?

Answer 5

• surgical removal of small amount of tissue from abnormal lesion
• sample undergoes histological examination
• excisional: all of lesion removed along with some normal tissue
• incisional: some of lesion removed along with normal tissue

Question 6

what are 3 types of biopsies? how is each carried out?

Answer 6

1. needle biopsy: special cutting needle takes core of tissue from lesion e.g. kidney or lymph nodes
2. punch biopsy: taken from surface of a lesion, several mm in diameter
3. aspiration biopsy: looking for cells in fluid

Question 7

3 types of diagnosis?

Answer 7

1. differential diagnosis: more than one possible option
2. provisional diagnosis: needs to be confirmed e.g. by biopsy
3. definite diagnosis: no more confirmation needed

Question 8

how do radiographs aid diagnosis? examples?

Answer 8

• they show changes in hard tissue mineralization:
  i. caries-> demineralization of teeth
  ii. periapical & periodontal disease: demineralization of surrounding bone
• examines areas of teeth and bone that are not clinically visible

Question 9

photographs: useful for?

Answer 9

• record soft tissue lesions
• record extent of injury following trauma
• record before and after views of dental treatment

Question 10

study models: used in what type of cases?

Answer 10

• orthodontic cases: determine if extractions are required, appliance design
• occlusal analysis: full mouth treatment required to determine the functioning of dentition; prosthetic/restorative cases, crowns, bridgework
• tooth surface loss: by either erosion or attrition, monitors tooth wear