2020 MSA Flashcards
What number of canals are found most often in an upper first premolar?
2
Where is the ideal end point of obturation?
The apical constriction
The CEJ
What is the term for maintaining communication between the pulpal space and peri-radicular tissues?
Patency
What is a working length in endodontics?
Distance from the occlusal reference point to the point at which the root canal preparation should stop
What two common intra-operative radiographs can be utilised during endodontic treatment to aid working length determination?
Working length radiograph
Master-cone radiograph
Give 2 potential causes of a corrected working length changing during the course of endodontic shaping
Perforation
Straightening of the canal
Which systemic antimicrobial is prescribed for necrotising gingivitis as well as dose, daily frequency and duration of administration?
Metronidazole 400mg 3x daily for 3 days
What 3 warnings should be given to a patient taking metronidazole?
Don’t consume alcohol
Don’t take if pregnant
Seek medical attention immediately if they experience signs of allergic reaction and stop taking the medication
What follow up care is arranged after necrotising gingivitis?
Review in 2 weeks
HPT therapy after acute symptoms subside
What is the difference between the mandible at rest and ICP?
Freeway space
What is the average freeway space?
2-4mm
What positions is the mandible in retruded axis between?
RCP
Retruded axis position
What is a border position?
A position determined by the anatomy of the TMJ 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?
Facebow
An interocclusal record
What is the average value of the sagittal condylar guidance angle which may be used on an articulator?
30º
What are the 2 main differences in composition between decorative and dental ceramic?
Decorative ceramic contains more Kaolin
Dental ceramics contain more feldspar
What does translucency mean with regard to optical properties of materials?
The degree 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 materials?
A translucent materials ability to appear orange in transmitted light and blue in refracted light
How can you modify the ceramic surface to make it more retentive prior to using silane?
Etch with hydrofluoric acid
Chemically how does a silane coupling agent work when bonding composite to ceramic?
C=C on one side of silane reacts to the composite
Oxide groups on other side of silane form strong bonds with the porcelain
What is the function of silane in a composite restorative material?
Improves bond strength between composite resin filler particles
List 4 features of an RCT
Randomisation
Blinding
Inclusion/exclusion criteria
Control group
How can randomisation be implemented in an RCT?
Use a computed generator to decide which participants are put into which group