Matrix for Direct Restorations Flashcards
When to se a matrix?
class II, III, IV cavities
as they present missing sections
A well applied matric band should do what?
- establish a contact point with the neighbouring tooth
- confine (box) the cavity to allow the restoration to be built up
- stop material being expelled to allow the restoration to be built up
- allow for physiological contouring of the cavity box area
- influence the surface texture of the restorative material, leaving it as smooth a possible
What are metal matrices made form?
stainless steel
What are the 2 most common types of matrices used?
Tofflemire
Siqveland
What material are sectional matrices?
clear plastic
Do you want the matrix to curve around the tooth?
yes and place a wedge
What is the purpose of a wedge?
to secure the matrix against the tooth
How do you check the effectiveness of the seal?
running a dental explorer between the box floor and matrix
What do you use to change the shape of the matrix
round or flat ended amalgam packer to burnish the matrix band
What is a burnisher?
used to build out the contour of te matrix from the box floor to the contact point
What is the advantage of the Tofflemire band with deep class II cavities?
they have curved area that engages further apically when applied
When placing a siqveland matrix band, what way should the latch face?
always be engaged to the cervical side of the tooth
to allow the band to flare coronally better
What is the apical edge of the tofflemire band like?
curved - easy to orientate
Where should the curved area of the tofflemire be placed?
beyond the box floor
What do you do after applying the matrix band?
apply a wedge
What types of material can automatrices come in?
metal or clear
What loads the automatrix?
autoloader
What are the 3 parts of a sectional matrix?
matrix
security clamp
wedge
Why use a sectional matrix?
nothing sticks out of the mouth
What are 2 reason for the matrix to not reach to the box floor?
the cavity extends subgingivally and the matrix is not wide enough or shaped to be positioned beyond the box
the matrix is prevented form being positioned apical to the box floor, due to the side tissue around the remainder at a more coronal position to the box
