random msa questions Flashcards
what are the three main routes of metastatic spread of cancer?
- lymphatic
- haematogenous
- transcoelomic
give one examples of a cancer which spreads?
colon cancer metastasises to liver
name 2 clinical classifications of tumours:
- benign
- malignant
name two histological classifications of tumours:
- epithelial
- mesenchyme
what are 5 features of benign tumours?
- growth is slow
- growth is non-invasive
- benign tumours do not spread
- do not recur when removed
- tumour margins are not well defined
name 5 features of malignant tumours:
- growth is rapid
- growth is invasive (destroys tissue)
- tumour spreads
- recurrence after excision
- tumour margins are well defined
name two benign tumours are their tissue of origin:
- lipoma = fat tissue
- chondroma = cartilage
name two malignant tumours and their tissue of origin:
- carcinoma = epithelial cells
- lymphoma = bone marrow/blood forming cell
name 4 demographic factors (characteristics of a population, expressed statistically):
- Age
- Sex/gender
- employment status
- postcode
briefly describe the Ingestion phase of feeding:
- movement of food from external environment to internal environment
- accomplished by biting and oral seal
briefly describe stage on of transport in the feeding cycle:
food is gathered on tongue tip and moved to the level of the posterior teeth
briefly describe the mechanical processing phase of the feeding cycle:
- solid foods are broken down and mixed with saliva before swallowing
- moist solid foods need to have fluid removed before transport & swallowing
- food is chewed with premolars and molars
- soft foods are squashed against the hard palate
what occurs in stage two of transport during feeding?
- bolus moved posteriorly by ‘squeeze back’ mechanism
- solid foods moved through fauces to pharyngeal surface of tongue
- ‘seal’ holds liquids at pillars of fauces
what occurs during the swallowing pharyngeal phase of the feeding cycle?
- involuntary movements push bolus through pharynx into oesophagus
- epiglottis seals of larynx preventing food entering the respiratory tract
- UOS relaxes, to allow bolus into the oesophagus and then contracts to counteract backflow
why might ditching occur in an amalgam restoration?
- material is repeatedly stressed for long periods at low stress levels: below elastic limit
- it may flow resulting in permanent deformation
- amalgam then sits proud of surface due to this flow, and is vulnerable to fracture
what can a dentist do, in terms of cavity prep, to avoid ditching in an amalgam restoration?
- remove all caries
- use acid etch and bond
- use a lining material
- lining material helps spread forces down the long axis of the tooth, instead of placing stress on the interface between tooth & restoration
- this reduced stress on the amalgam therefor reducing creep & therefor reducing ditching
what are examples of 4 factors that may contribute to secondary caries in an amalgam restoration?
- microleakage due to no chemical bond between restoration and tooth
- fracture of enamel at margins causing ditching has compromised any seal that was present at the restoration/tooth interface
- poor oral hygiene will prevent removal of plaque
- there is no lining material underlying the amalgam, meaning the dentine has no protection from bacteria and endotoxins
what are 5 risk factors that make someone a high caries risk?
- poor oral hygiene
- poor diet
- xerostomia
- frequency of sugar intake
- susceptible tooth surface (tight contacts, receded gingiva)
how is cystic fibrosis acquired?
it is an inherited disorder
- CFTR gene - chromosome 7
- recessive gene
- both parents must have it
what are the treatment options for a patient suffering with cystic fibrosis?
- physiotherapy
- exercise
- medication
- transplantation
how does cystic fibrosis affect the body?
- inherited gene defect in cell chloride channels
- produces excess sticky mucous
- lungs are congested
- malabsorption of nutrients in the pancreas
how can you test for cystic fibrosis?
- perinatal testing (all children are now screened at birth)
- sweat test (measures salt content of sweat which is higher in CF patients)
what are the three main stages in forming a blood clot?
- vasoconstriction
- platelet plug & aggregation
- fibrinogen to fibrin
define bioavailability:
fraction of an administered dose of unchanged drug that reaches the systemic circulation and is available for clinical effect
describe first past metabolism:
- concentration of drug is greatly reduced before it reaches the systemic circulation
- fraction of the drug is lost during the process of absorption in the gut and metabolism in the liver
what are 2 disadvantages of administering drugs via the oral route?
- first pass metabolism occurs
- risk of drug causing gastric irritation & ulceration (NSAIDs eg.)
what are the 9 SICPs?
- patient placement
- safe waste disposal
- safe handling of uniform
- cleanliness of environment
- cleanliness of care
- prevention of exposure to BBV
- management of bodily fluid spillages
- PPE
- hand hygiene
what are the 6 links in the chain of infection?
- infection agent
- reservoir
- portal of exit
- mode of transmission
- portal of entry
- susceptible host
what are the 7 modes of transmission?
- direct
- indirect
- inhalation
- ingestion
- inoculation
- intercourse
- mother to infant
what are the 5 moments for hand hygiene in a clinical environment?
- before touching a patient
- before a clean/aseptic procedure
- after bodily fluid exposure risk
- after touching the patient
- after touching patient surroundings
“Washing with an alcohol based gel when hands are not visibly soiled” - is this an example of social or hygienic hand hygiene?
- social hand hygiene
what is ‘hygienic’ hand hygiene?
washing with an antimicrobial scrub, or washing with hot water and soap followed by an alcohol based gel
in a clinical environment, when would it not be appropriate to use an alcohol based gel to wash your hands?
- if hands are visibly soiled
- C. Difficile risk
- if patient has a GI infection
when should sharps containers be disposed of?
3/4 full
what happens to sharps when they are taken away?
they are taken for incineration
where should sharps boxes be placed within the clinical environment?
- out of reach of children
- close enough to operator for each reach when disposing of sharps
what must you do in the events of a sharps injury?
- stop any dental procedures
- squeeze to encourage bleeding
- run the injury under lukewarm water
- wash thoroughly with soap and water but do not scrub
- cover site with waterproof dressing
- complete incident report form & report to occupational health
what are the three methods of decontamination?
- cleaning
- disinfection
- sterilisation
what are some advantages of using the hall technique?
- non-invasive and quick
- required no LA, requires no tooth prep
- requires no tooth prep
what instruments are required when performing the hall technique?
- mirror
- straight probe
- excavator
- flat plastic
- cotton wool
- gauze for airway
- band forming pliers
what teeth are suitable for the hall technique?
primary molars (Es and Ds)
what are the indications for use of the hall technique?
- no radiographic sign of pulpal involvement
- sufficient amount of sound tooth tissue
what are the components of stainless steel?
- iron
- carbon
- chromium = corrosion resistance
- nickel = lowers critical temperature
what are the advantages of using stainless steel?
- high proportional limit
- high tensile strength
- ability to be hardened by heat treatments
what is a disadvantage of using stainless steel?
susceptible to corrosion
list four emergency drugs ESSENTIAL for every dental practise?
- GTN spray
- adrenaline
- oral glucose/glucagon
- salbutamol inhaler
list four pieces of emergency pieces of equipment essential for every dental practise:
- oxygen face mask & tubing
- external defibrillator
- pulse oximeter
- blood glucose measurement device
where is LA deposited during an IAN block?
deposited around the nerve trunk
what is the pterygomandibular raphe?
Ligamentous (fibrous) band attached to the hamulus of the medial pterygoid muscle and the mylohyoid
which structures enter the mandible at the mandibular foramen?
- inferior alveolar nerve
- inferior alveolar artery
sometimes during an IAN block, advancing the needle may encounter the lingual of the mandible. What is this?
- prominent bony ridge at the entrance to the mandibular canal
- attaches the sphenomandibular ligament
where is LA deposited during infiltartion? (in relation to nerve)
deposited around terminal branches of nerve
outline briefly, two drawbacks of CoCr?
- low ductility (doesnt have a great ability to deform under stress and has a very high Young’s Modulus; clasps are not flexible & cannot fit in undercuts >0.25mm)
- CoCr is difficult to adjust once made, requires precision casting when mad as it work hardens rapidly
- aesthetics ugly
what are advantages of light cured materials?
- extended working time
- less finishing
- less waste
- less porosity
name a few criticisms for using flowable composite:
- reduced mechanical properties
- lower availability of shades
- more difficult to sculpt
- discolouration over time
