2021 MSA Part 2 Flashcards
What collimating error has occurred when there is incorrect alignment between the X-ray tube and receptor holder?
Cone cutting
What faults in the placement of an amalgam restoration can lead to overhangs? (2 marks)
Too much force when condensing amalgam
Poor adaptation of the matrix band
What problems can amalgam overhangs give rise to in the short term and long term?
Short term:
- food trap
- difficulty in cleaning
Long term:
- secondary caries
- periodontal disease
List two ways to correct an amalgam overhang
Polishing using a finishing bur
Replacement of the restoration
What further investigations can be carried out in a patient with a necrotising periodontal disease?
Radiographs to determine if there is any bone loss
Give 3 disposing factors of necrotising periodontal disease
Any 3 from:
Psychological stress
Poor OH
Lack of sleep
Smoking
Immunosuppression
Malnutrition
What are the risks of no tx in necrotising periodontal disease?
Tooth loss due to rapid bone destruction
What tx is provided on the first visit for necrotising periodontal disease? (3 marks)
Ultrasonic debridement
0.2% chlorhexidine mouth wash twice daily
OHI - don’t brush until acute symptoms subside
What antibiotic and dosage should be prescribed for acute tx of necrotising periodontal disease and for how long should the patient take it?
Metronidazole - 400mg 3 times daily for 3 days
When should a necrotising periodontal disease patient be seen for review after tx of initial symptoms?
1-2 weeks
What is the distance between the mandible at rest and in ICP called?
The freeway space
What is the average distance of the freeway space?
2-4mm
The mandible is said to be on its retruded axis when it occupies any position between what points?
Retruded axis position and retruded contact position
What is a border position of the mandible?
Mandibular position determined by the anatomy of the TMJ of and its musculature
Why is the retruded axis important in clinical dentistry?
It is a reproducible jaw position
What two records are required for mounting casts on a semi adjustable or average value articulator?
The relationship of the maxilla to the hinge axis of rotation of the mandible
An interocclusal registration
What is the average value of the sagittal condylar guidance angle which may be used on an articulator?
30º
Name the design principles outlined by Herbert Schilder
Create a continuous tapering funnel
Maintain apical foramen in the original position
Keep apical opening as small as possible
Besides disinfection of the root canal space, name two other objectives or irrigant use in root canal treatment
Lubrication of the root canal space
Removal of debris
What is the ideal primary endodontic irrigant and at what concentration range is it most effective?
Sodium hypochlorite
Between 0.5 and 6%
Name three factors important for the function Sodium Hypochlorite
Concentration
Volume
Contact time with root canal walls
What are the two main differences in composition between decorative and dental ceramic?
Decorative ceramics contain more Kaolin
Dental ceramics contain more feldspar
What does translucency mean with regard to optical properties of a material?
The ability of a material to allow light to pass through but be scattered at one of the surfaces or internally leading to a blurring of the transmitted light
What does opalescence mean with regard to optical properties of a material?
A materials ability to reflect, scatter and refract light
How can ceramic surfaces be modified to make it more retentive prior to using silane?
Acid etch with hydrofluoric acid
Chemically how does a silane coupling agent work when bonding composite to ceramic?
C=C bonds on one side of silane react with the composite
Oxides groups on other side of silane form strong bonds with the porcelain
What is the most common cause of facial trauma in a female patient
Physical abuse
Aside from physical violence list four other forms of abuse that might be involved in domestic abuse?
Verbal
Emotional
Sexual
Financial
What process should you follow to ask about the possibility of domestic abuse and briefly describe? (4 marks)
AVDR
Ask
Validate
Document
Refer
List four physical signs you might see in domestic abuse
Repeated injuries
Bruises at different stages of healing
TMJ problems
Strangle marks around the neck
List two categories of patient who may be considered to be more at risk in terms of domestic abuse than others
Women who are separated
Those with mental health problems
List four benefits that digital radiography has over film radiography
No need for chemical processing
Easy storage of images
Easy back up of images
Images can be integrated into digital patient records
What is the benefit of using rectangular collimation? (2 marks)
It can reduce effective dose to the patient by approximately 50%
What chemical property of lead makes it particularly effective at absorbing X-ray photons?
It’s high atomic number
What is the minimum distance it is recommended a dentist stands away from the X-ray source?
1.5m
What does the term justification mean in the context of decision whether or not to take a dental radiograph?
Taking the radiograph must have sufficient benefit to the individual in order to offset the detriment
What does ALARP stand for?
As low as reasonably practical
Name two characteristics of biofilm ECM that confers resistance from antimicrobial agents
Biofilms produce an LPS protective barrier
Biofilms impair diffusion of antimicrobials
Name two important bacteria clearly implicated in periodontal disease, based on Socransky’s red disease complex
P. gingivalis
T. forsythia
Name two bacteria associated with caries development
S. mutans
A.a.
What two key features enable cariogenic organisms to stick to enamel surfaces and autoaggregate, and to survive within an acidic environment?
Glucans - attach to enamel
ATPase - controls the pH
Name two systemic diseases that have been shown to be associated with periodontal biofilms
Cardiovascular disease
Diabetes mellitus
In the correct order, what are the 5 core stages of the washer-disinfect or cycle and what are their functions?
Pre wash - removes gross contamination
Main wash - detergent is added to remove biological matter
Rinse - removes residual contamination
Thermal disinfection - actively kills microorganisms with heated water
Drying - uses hot air to remove moisture
What does PICO stand for?
Population
Intervention
Comparison
Outcome
