Ch.49 Flashcards
(27 cards)
What matrix system is the most common for a MO on #30?
Tofflemire retainer and universal band
Where is the wedge positioned when placing a posterior filling?
Lingual
The retainer designed with a slight bend in it is called the __________.
Contra angle
The tofflemire holds the band snugly in position, it is most often positioned in which area?
On the buccal surface of the tooth being restored.
What is the purpose of matrix system?
To provide a temporary interproximal wall for the filling
A matrix is used to create a temporary wall for what class fillings?
Classes II , III and IV
What matrix would you pick for anterior restorations
Clear plastic matrix
Which type of band is most selected for the primary molars?
T-band
Which statement is correct regarding posterior metal matrix bands?
The smaller circumference is placed toward the gingiva
To contour the band for posterior teeth, rub it with ______ until it curls
A burnisher or end of a mirror handle
Which of the following is the instrument of choice when positioning a wooden wedge?
Howe pliers
Where should the cervical margin of a matrix band lie?
1 mm beyond the gingival margin of the preparation.
What is the material of choice for a universal matrix band?
Thin, flexible stainless steel
If a cusp is fractured, which matrix band would provide the best support while filling it?
Extension
Why is a matrix band contoured?
To ensure the final restoration has proper contact with the adjacent tooth
A plastic matrix strip is contoured by pulling the matrix lengthwise over the :
Rounded end of cotton pliers
Mylar strip are used for Class ____ restorations.
III
Which of the following dental instruments is used to contour an anterior matrix band?
Mirror handle
What is one advantage of an AutoMatrix over a universal matrix?
No retainer to hold the band in place.
Once the AutoMAtrix band is positioned on the tooth, how is the band tightened?
A wrench turns the coil clockwise to tighten the band
Which matrix system is preferred with posterior composite restorations?
Palodent
If a restoration is not contoured properly, it can result in an :
Overhang
What is the component of a universal matrix retainer that serves to hold the matrix band securely in the retainer?
Outer knob
What is the component of the universal matrix retainer that holds the matrix band securely in the device called?
Spindle
