Restorative - Final Exam Study Questions Flashcards
What class of cavities is a matrix used for?
Class II, III, and IV
What is the shape and material of a maxtrix determined by?
The shape of a matrix system and or the material used is determined by its location and for what type of cavity prepartion.
What are circumferential matrices usually used for?
Matrices that are circumferential are usually used to replace proximal, facial, or lingual walls.
What are sectional matrices usually used for?
Sectional matrices are used for missing proximal walls.
What are cervical matrices used for?
Cervical matrices are used for Class IV restorations.
Benefit of Clear Plastic Matrix system?
A matrix system made of clear plastic will allow the operator to utilize the curing light more effectively when placing a light cured restorative material. They are often used for anterior restorations of Class IV buccal restorations.
What are Wedges?
Wedges may be used in conjunction with a matrix system to achieve proper interproximal contacts. They are placed next to the matrix band using wedge placement forceps or cotton forceps, into the embrasure space for each missing proximal wall.
The function of wedges is to:
Hold the matrix band firmly against the gingival margin of the preparation
-To prevent overhangs on restorations.
- Provide slight separation between the teeth, ensuring an accurate contact space and compensating for the thickness of the matrix band, creating a tight contact between the finished restoration and the adjacent tooth
The most commonly used shape of wedge is?
The most commonly used type of wedge is triangular.
What to consider when using a wedge?
- The wedge must be wide enough so that pressure is applied to the apical and gingival walls of the preparation.
- The wedge presses the band against the tooth and causes a slight separation of the teeth.
3.The wedge is slightly wider than the distance between the cervical portions of adjacent teeth.
What class of cavities is Celluloid strip matrix system used for?
Class III or IV when the proximal wall of an anterior tooth is missing
The plastic matrix (also called celluloid strip or mylar strip) and wedge serve the following purposes during the restoration process:
-The matrix is placed interproximal before the etching and bonding of the tooth to protect adjacent teeth from these materials.
-After the placement of composite material, the matrix is pulled tightly around the tooth to help in reconstructing its natural contour.
-The clear plastic matrix allows the curing light to penetrate the material, thereby completing the curing process.
What is the T-band matrix system?
The T-band is a band in the shape of a T that can be easily placed, contoured and removed. When formed, the top portion of the T allows the straight portion to adjust and fit the circumference of a primary molar.
Properties of a T-Band Matrix
-The T-band is available in two types, narrow width, and wide width, with a choice of stainless steel or brass material.
-The material is sturdy but can be adequately contoured.
-The loop may be prepared in advance and slipped over the tooth and tightened before the preparation is made to save time.
What is a sectional matrix system?
The sectional matrix system facilitates the implementation of tight, anatomically correct contacts for Class II and MOD posterior composite restorations. The sectional system uses small contoured sections, rather than long cicrumferential bands, which are placed interproximally and secured by tension rings.
Components of a Sectional Matrix System
1.Different sizes of contoured sectional matrix beans.
2.Two tension rings with differing tine lengths (long and short). The ring is applied to the tooth after the matrix bean is in place.
3. Tension ring forceps used to open the ring.
How to use a sectional matrix system
One sectional matrix bean is applied for each interproximal surface being restored. The system allows for the overlapping of tension rings when doing a MOD or for multiple restorations in one quadrant. Using the tension ring forceps, the tension rings are applied to the tooth after the sectional matrix bean and wedge is in place. The tension ring is placed with the tines between the sectional matrix bean and the wedge.
What is a Tofflemire Retainer?
The Tofflemire matrix system is a metal device consisting of a retainer and a band used for posterior restorations. It is one of the oldest systems and most commonly used.
The 3 types of retainers:
- Universal (buccal)
- Contra-angle (lingual)
- Pediatric
Description of Universal (buccal) retainer?
The buccal retainer has guide channels that are flat or even with the diagonal slot vise. This retainer sits flat against the teeth in the mucco-buccal fold and the retainer is always placed on the buccal surface of the tooth.
Description of Contra-angle (lingual) retainer?
The lingual retainer has the guide channels set at an angle to the diagonal slot vise and this retainer is always placed on the lingual surface of the teeth. When the retainer is in place, it lies at an angle to the teeth so the metal does not damage the enamel surface of the remaining teeth in the arch.
Description of Pediatric retainer?
The pediatric tofflemire retainer is smaller in all dimensions than the Universal or Lingual retainers to accommodate the smaller mouth of a child.
Retainer Components
- Guide Channels
- Diagonal Slot Vise
- The Spindle
- Inner Nut
- The Outer Nut
What is the purpose of guide channels on retainer?
Enable the loop of the matrix band to be guided in one of three directions. The direction selected is determined by the quadrant involved.
What is the purpose of a Diagonal Slot Vise on retainer?
Is used to position the ends of the matrix band within the retainer.
What is the Spindle purpose on retainer?
Is a screw that is used to hold the ends of the matrix band securely in the diagonal slot vise.
What is the purpose of the Inner Nut on retainer?
Is used to adjust the size of the matrix band around the tooth
What is the purpose of the Outer Nut on a retainer?
Is used to tighten the spindle and position it within the diagonal slot vise.
How to assmble a retainer?
- Look carefully at your retainer and note the side with the diagonal slot where the ends of the band are placed into.
- This side of the retainer is always placed toward the gingival margin of the tooth.
3.This may be easier to remember when you realize that after the operator has placed the restoration, they will remove the matrix retainer first, temporarily leaving the band in position.
4.The only way this can be done is if the diagonal slot is toward the gingiva and the retainer can be lifted away from the band. - Look at the spindle in your retainer.
- Before beginning to assemble the retainer and band, the spindle point must be clear of the diagonal slot.
- Turn the spindle away from the diagonal slot.
- To adjust the spindle, turn the outer nut counter-clockwise until the spindle is no longer visible in the diagonal slot.
CAUTION – if you turn the spindle too far counter-clockwise, the diagonal slot vise will fall off the spindle. If this happens, insert the end of the spindle into the diagonal slot vise and turn the outer nut clockwise.
How many classifications of cavities are there?
6
Who invented Cavity Classifications?
Dr. Black
How are cavities classified?
By the surfaces involved
What classification occurs on the surfaces associated with pits and/or fissures?
Class 1
What classification of decay occurs on the proximal surfaces of the premolar and molars?
Class 2
What classification of decay occurs on anterior teeth and involves an interproximal surface only?
Class 3
What classification of decay occurs on the interproximal surface and involves the Incisal edge of the tooth?
Class 4
What type of decay occurs on the gingival 3rd of the lingual or buccal (facial) surface on any tooth
Class 5
What is Class VI decay caused by?
Decay that occurs as a result of abrasion (wear) and defects on the incisal or occlusal edge of any
tooth (smooth surface).
Tooth decay, is also referred to as…
Cavity, dental lesions or caries
A 16-year-old patient, came for their 6 months check up with the dentist. The dentist diagnosed tooth
2.6 with having decay involving the MOD surfaces. What classification of decay is present on the
patient’s tooth?
Class 2
The above patient came back 1 year later and the dentist diagnosed the same tooth (2.6 MOD) with
decay again. The patient just had the tooth restored. What kind of decay is present on the patient’s
tooth?
Secondary (recurrent) caries that occur around restorations and require replacement
A 5-year-old patient has extensive restorations present on their primary teeth. The grandmother
always let them fall asleep drinking warm milk in the past. What type of decay do you think the
patient had in the past?
Rampant caries – multiple lesions throughout the mouth caused by excessive intake of
sucrose
The following teeth; 4.5 buccal pit, 4.6 occlusal, 2.1 lingual pit have cavities. The dentist described
them to you by the surfaces involved. Is the classification of these cavities considered?
) Simple Carious Lesions involves only 1 tooth surface
The following teeth: 4.5 MO, 4.6 DO, 2.1 MI have cavities. The dentist described them to you by the
surfaces involved. Is the classification of these cavities considered?
Conservative Carious Lesions involve 2 tooth surfaces
The following teeth; 4.5 MOD, 4.6 MODB, 2.1 MIL have a cavity. The dentist described them to you by
the surfaces involved. Which cavity classification surface is involved?
Comprehensive Carious Lesions involve 3 or more tooth surfaces, along with the removal of a
cusp.
What are the objectives for initial cavity preparation?
Outline form - is the overall shape of the preparation along the external surface of the enamel or the Cavo-surface margin.
Resistance form - is the internal shape of the cavity preparation.
Retention form - is the relationship that exists between different walls of the preparation.
Convenience form
Which step in the initial preparation allows the dentist to determine the design?
Outline Form
What are the three steps in the final preparation process?
a) Remove any remaining enamel, diseased dentin or old restorative material within the
preparation.
b) Insert additional resistance and retention notches, grooves and coves to provide strength in
maintaining the restoration.
c) Place dental materials.
What instrument is used to bevel the mesial cervical walls in a cavity preparation?
Gingival margin trimmer mesial
Which instrument is used with a push motion to cut, clean and smooth the walls in a cavity
preparation?
Enamel hatchet
The instruments whose function is to clean and smooth the floor and walls in a cavity prep? It is
also used with a pulling motion.
Enamel hoe
Which instrument is used to create bevels on the distal cervical margin of the preparation?
Gingival margin trimmer distal
What instrument is used to remove carious dentin in a cavity preparation.
Spoon excavator
Which instrument is used with a push motion to plane and cleave enamel in a cavity preparation
and has a curved blade on the working end?
Wedelstaedt chisel
What bur adds retention to the walls of the cavity preparation and also has a “flat” top?
inverted cone
The bur that cuts into and forms the inner walls of the cavity preparation is the:
Fissure bur (straight, tapered, or crosscut)
What instrument is used to accentuate line and point angles in a cavity preparation?
Angle former
Which bur removes caries, and can open the tooth for endodontic treatment?
Round bur
If patient is feeling closterphobic when a dental dam is applied - what can you do to assist?
Cut a hole in the dam, fold the top of the dam down below the patients nose
What thickness is a base when properly placed within a cavity preparation?
1-2 mm
What clamp would be used to clamb the 4.4?
2A
WHERE IS A BASE PLACED WITHIN THE CAVITY PREPARATION?
On the pulpal floor
What is a benefit of glass ionomer as a liner?
It releases fluoride
What type of matrix would be used for a 2.6 MOD Composite restoration?
2 sectionals
What type of sectional is only used on primary teeth?
T-Band
What type of matrix would be used for a 4.7 DO Amalgam?
Tofflemire
What type of matrix would be used for a 1.1 MIL composite restoration?
Celluloide
What type of matrix would be used for a 2.6 DOLB composite?
Tofflemeire - BECAUSE OF LINGUAL
How many points are on a dental dam frame?
7
What is NOT a prupose of the dental dam napkin?
Increases visibility
Where is the liner placed within a cavity preparation?
Within the deppester part of the cavity prepartion
What type of bur is used in a slow speed handpiece to primary remove caries from the tooth structure?
Round bur *slow speeeeed**
What type of bur is used to form angles and and retention grooves in the walls of a cavity preparation?
tapered fissure
What might occur if the dental dam holes are punched too close together?
There would be streching
What insrument is used to accentuate line and point angles in internal outline and retention in cavity preparation?
Angle former
What hand cutting instrument is used for anterior restorative procedures to plane and cleave enamel?
Straight chisel
What type of retention do hand cutting instruments help create within a preparation?
Mechanical
What type of bur grip is used in a high speed handpiece?
Friction grip
What type of bur is used to form the walls of a cavity preparation?
straight fissure
What type of bur has the most number of blades or flutes on the cutting end?
Finishing - gold shank!
What instrument is used to bevel cervical walls of mesial and distal retention areas?
Margin trimmer
What type of hand cutting instrument will be used to manually remove decay?
Spoon excavator
What type of liner produces secondary dentin?
Calcium hydroxide
Explain the term “Smear layer”
When cutting a cavity preparation, there will be dust from the enamel/dentin, as well as fluid from the dentinal tubules adhering to the inner walls – this is called the smear layer
Desicate means..
desiccation process works by using a liquid or gel that essentially wicks away the moisture from its surroundings, including biofilm and infected microbial or necrotic material.
Polymerize meaning..
polymerization is a chemical process that turns a liquid resin into a solid by forming bonds between resin molecules
Steps in Cavity Preparation
Outline Form – dentist decides on the design and initial depth, create outline walls of cavity prep & cavosurface margin
Resistance Form – create inner walls of cavity prep
Retention Form - the relationship of walls within cavity prep – used to create better retention
Convenience Form – dentist has accessibility to the tooth to prepare and restore the tooth
Advantages of using a glass ionomer as a liner?
- Contains fluoride - anti-cariogenic properties
- Bonds to tooth structure - is attracted to the fluid within the dentinal tubules
- Prolonged setting time due to it being light cured
What should you do if bleeding and or moisture contaminated the area of liner placement?
- Notify dentist
- Dentist will remove contaminated material
- Clean and dry area again
- Re-apply material
Advantages of Calcium Hydroxide?
- protects the pulp from chemical irritation through sealing abilities
-stimulates production of reparative/secondary dentin
-is used for pulp capping of pulpal exposure and near exposure
-is compatible with all types of restorative material
Advantages of Polycarboxylate?
- bonds to tooth structure, as it is attracted to the natural fluid within the dentinal tubules
-contains stannous fluoride to provide anti-cariogenic properties
-not acidic and does not irritate the pulp
-can be placed under ALL types of direct and indirect restorations
Disadvantages of Polycarboxylate?
- has a very short working time - less than 25 seconds
-the bonding properties of the cement are lost once the mixed material loses its glossy appearance
The component of a universal matrix retainer that serves to guide the direction of the matrix loop accoriding to the quadrant that is being treated is the…
outer guide slots
Purpose of a spindle in the tofflemeire/universal matrix retainer?
the spindle is a screwlike pin that fits into the diagonal slot to hold the ends of the matrix band
The purpose of the inner knob in the tofflemeire/universal matrix band?
changes the size of the matrix band loop
Purpose of the diagonal slot in the tofflemeire/universal matrix band?
the diagonal slot positions the ends of the matrix band into the vise
A matrix must be used to create a temporary wall for which of the following classifications of tooth restorations?
Class II, III, and IV
The component of the universal matrix retainer that is always positioned in the mouth facing the gingiva is..
the diagonal slot
The larger side of the universal matrix band loop is always toward the _____ third of the tooth.
Occlusal
_______ is the term to describe an indentation of the restorative material on a tooth surface that has not been contoured properly
Cupping
When is a sectional contraindicated?
When the lingual/buccal wall is missing
When is a tofflemerei preferred over a sectional?
When placing an Amalgam
The most common matrix system used for class II posterior restorations is the …
Tofflemire retainer and matrix band
The universal, or Tofflemire, retainer holds the matrix band snugly in position and is most often positioned:
on the buccal surface of the tooth being restored
A ______ tofflemire retainer has been designed with a slight bend in the body to accomodate positioning from the lingual surface.
Contra-angle
The ____ is used for anterior composite resin or glass ionomer restorations..
clear plastic matrix
The ____ is used as a matrix system for the primary molars.
T-band or spot-welded band
What is true of posterior metal matrix bands?
the smaller circumference is placed toward the gingival edge
To contour a metal matrix band for posterior teeth, place the band on a paper pad and rub the inner surface of the band with _____ until the ends begin to curl.
a burnisher or the end of a mirror handle
Which of the following is the instrument of choice when positioning a wooden wedge?
Howe pliers
When a posterior metal matrix band and retainer are placed, the seated matrix band should extend approximately _____ mm below the gingival margin of the preparation.
1 mm
The purpose of a matrix system is to:
provide a temporary interproximal wall for the restorative material.
create an external surface against which the restorative material is packed.
The material of choice for a posterior matrix band is:
thin, flexible stainless steel
If there is a loss of a cusp making the preparation deeper, a(n) _____ band may be selected.
extension band
The extension band is used for the deeper class II preparations that require gingival extensions to compensate for the loss of a cusp.
The purpose of contouring a matrix band is to:
ensure that the final restoration will have proper contact with the adjacent tooth.
Which statement is true concerning wedges?
a. A wedge is used to apply pressure to the apical and gingival walls of the preparation.
b. The wedge presses the band against the tooth, causing a slight separation of the teeth.
For posterior restorations, the wedge is positioned from the _____ side.
lingual
Stainless steel matrices cannot be used for anterior composite resins because the:
-resins can be scratched by the stainless steel.
-stainless steel can interfere with the setting of the resins.
Mylar strips are used for class ___ restorations.
Class III
To create a solid closure of the cavity preparation for posterior composite restorations, the prongs of the tension ring for the G-Ring systems are placed _____ the band and wedge.
between
What is the correct order of steps for preparing the T-band matrix?
- Bend the wings of the T-band to form a U-shape.
- Slip the free end of the band through the U formation.
- Close the wings and pull the free end to make a small loop of the band.
- Holding the free end of the band toward the facial, place the band loop on the tooth.
Excess restorative material that extends beyond the cavity margin is a/(n):
overhang
The component of a universal matrix retainer that serves to guide the direction of the matrix loop according to the quadrant that is being treated is the:
outer guide slots
The component of the universal matrix retainer that holds the matrix band securely in the device is the:
Spindle
The component of the universal matrix retainer that is always positioned in the mouth facing the gingiva is the:
Diagonal slot
The ____ is used to decrease the size of the matrix band loop after the band has been placed on the tooth.
inner knob
The larger side of the universal matrix band loop is always toward the____ third of the tooth.
occlusal
