Isolation and matrix systems

Question 1

What substances does a tooth need to be isolated from?

Answer 1

blood, GCF (gingival crevicular fluid), saliva, soft tissues

Question 2

What is the purpose of tooth isolation?

Answer 2

to achieve dry, clean, visible and safe field of work

Question 3

What are the different methods of tooth isolation?

Answer 3

sterile gauze, dental dam, saliva ejector, cotton roll

Question 4

Where are cotton rolls placed?

Answer 4

lingual and buccal vestibules

Question 5

Function of cotton rolls

Answer 5

retract soft tissue, absorbs water and saliva from salivary glands

Question 6

What are the advantages of cotton rolls?

Answer 6

simple to use and inexpensive

Question 8

What are the limitations to cotton roll use?

Answer 8

needs frequent replacement as its easily saturated with saliva, not stable - needs to be supported with mirror/aspirator

Question 9

Which procedures may cotton roll be used for?

Answer 9

fluoride application, amalgam placement, fissure sealant, cementing PFM / temp crowns and bridges

Question 10

What is the function of saliva ejectors?

Answer 10

removing excess moisture (insufficient at retracting alone)

Question 11

What are the advantages of saliva ejectors?

Answer 11

reduce saliva, water sprays and aerosols. inexpensive

Question 12

What are the limitations of saliva ejectors?

Answer 12

less effective if used alone (should be combines with cotton rolls)

Question 13

Which procedures can saliva ejectors be used for?

Answer 13

ultrasonic scaling (PMPR), cavity cutting, amalgam restorations, fissure sealant, cementing PFM / temp crowns and bridges

Question 14

What is the condition used to describe an enlarged tongue?

Answer 14

macroglossia

Question 15

Purpose of sterile gauze

Answer 15

cleaning mirror and stopping bleeding by packing over injury (not used for isolation)

Question 16

What are the advantages of using sterile gauze?

Answer 16

simple and inexpensive

Question 17

What are the limitations of sterile gauze?

Answer 17

easily saturated (very thin but this makes it easy to handle)

Question 18

What are the advantages of dental dam use?

Answer 18

tissue retraction and protection, airway protection, improves accessibility, excellent moisture control, improves sterility (accidental pulp exposure/deep cavity)

Question 19

What are the limitations of dental dam?

Answer 19

technique sensitive, patients might not tolerate it

Question 20

Which procedures is dental dam essential for?

Answer 20

RCT and vital pulp therapy

Question 21

Which procedures can a dental dam be used for?

Answer 21

amalgam removal, caries removal (avoid contamination), adhesive dentistry, endodontics, cementing ceramics

Question 22

What armamentarium is required to place a dental dam?

Answer 22

dental dam sheet, frame, punch, clamp, forceps/clamp holder

Question 23

What is the difference between molar clamps and premolar clamps?

Answer 23

premolar clamps have a smaller / narrower hole

Question 24

Which clamps are used for anterior teeth?

Answer 24

butterfly clamps

Question 25

What type of clamp is used for a partially erupted molar?

Answer 25

clamp where one side is more cervical / slightly subgingival to retract the gingivae and expose cervical margin

Question 26

What is the advantage of using a winged clamp?

Answer 26

achieves more retraction and holds dental dam

Question 27

What is the advantage of using a wingless clamp?

Answer 27

can be used with limited mouth opening

Question 28

What are the different techniques of dental dam use?

Answer 28

single tooth isolation, multiple tooth isolation, split dam

Question 29

What procedures can be done with single tooth isolation?

Answer 29

RCT, single tooth restoration (class I, III, V)

Question 30

How is a split dam created?

Answer 30

connect holes by scissors so that the gingivae can be seen interdentally

Question 31

What procedures require multiple tooth isolation / split dam?

Answer 31

class II cavities and multiple tooth preparation, restoring proximal contacts, quadrant procedures, cementation of indirect restorations (need to remove excess interproximal cement)

Question 32

What is a matrix system?

Answer 32

a temporary wall placed around a prepared tooth cavity to help contain and shape the restorative material

Question 33

What are the importances of matrixing and wedging?

Answer 33

restoring missing wall, prevents overhangs, restores contour and contact, facilitates proper anatomy (marginal ridge), helps adaptation of material (packing against wall)

Question 34

What are the 2 types of matrix systems?

Answer 34

circumferential and sectional

Question 35

What is a circumferential matrix system?

Answer 35

matrix band that completely encircles the tooth with a screwing to tighten the loop

Question 36

When would a circumferential matrix system be used?

Answer 36

MOD cavity to restore both walls at the same time

Question 37

What are sectional matrix systems?

Answer 37

a shorter matrix strip that is held against a single tooth surface by a clamp

Question 38

When would a sectional matrix system be used?

Answer 38

to restore proper contact for a single missing wall or 2 proximal walls in two steps

Question 39

What should you always check your matrix system for?

Answer 39

no open gaps or contacts (use probe to check) and should not be able to see dam or gingiva (would lead to leakage)

Question 40

What is wedging used for?

Answer 40

to prevent overhangs and leakage

Question 41

What are the consequences of improper wedging?

Answer 41

plaque retentive areas (overhangs), gingivitis, periodontal disease, leaking restorations, food impaction and therefore secondary caries

Question 42

What should you do before placing a matrix band?

Answer 42

check wedge size (S, M, L) by seeing how smoothly it is inserted and how well matrix band is seated

Question 43

What happens if you use a matrix band that is too large?

Answer 43

teeth will be separated too far resulting in an open contact where food can collect

Question 44

What should you do after class II restorations?

Answer 44

floss interproximally and post-op bitewings to check contour and gingival seal