NJXDG EVALUATION EXAM 2026 QUESTIONS AND
SOLUTIONS RATED A+
✔✔Dental dam clamps - ✔✔The dental dam clamp is the primary means of anchoring
and stabilizing the dental dam.
Clamps are made of chrome or nickel-plated steel and are designed to hold the dental
dam securely at the end nearest the tooth that is being treated.
The opposite end of the dental dam application will also be stabilized, and this is
accomplished w the use of either another clamp, a dental dam stabilizing cord, or dental
floss or tape. This technique is known as ligating the dam.
✔✔Parts of the dental dam clamp - ✔✔The parts of the clamp that are important to
identify are the bow and the jaws.
The bow is the rounded portion of the clamp that extends through the dental dam. The
clamp is always positioned on the tooth so that the bow is located at the distal aspect.
The jaws encircle the tooth and are shaped into four prongs. All four prongs must be
firmly seated on the tooth to create facial to lingual balance necessary to stabilize the
clamp. A hole is located on each side of the jaw of the clamp. The beaks of the dental
dam forceps fit into these holes to allow placement and removal of the clamp.
A winged clamp "W" is designed with extra extensions to help retain the dental dam.
Wingless clamps have numbers/letters that begin w the letter W and do not have extra
projections to engage the clamp.
✔✔Fitting the dental dam clamp - ✔✔Jaws of the clamp are designed to fit the cervical
area of the tooth below the height of contour and at, or slightly below, the
cementoenamel junction. The height of contour is the widest point on the facial and
lingual contours of the tooth.
The clamp must be positioned with all 4 prongs firmly in place on the tooth before the
clamp forceps are loosened. If the clamp is not placed properly, it may spring off.
✔✔Posterior dental dam clamps - ✔✔Used for the maxillary and mandibular posterior
teeth.
These clamps are universal, meaning the same clamp can be placed on the same type
of tooth in the opposite quadrant.
Clamps 7 and W7 are universal mandibular molar clamps, and clamps 8 and W8 are
universal maxillary molar clamps.
,✔✔Anterior dental dam clamps - ✔✔Such as clamps 9 and W9, are designed, to retract
the gingiva on the facial surface, improve visibility for the restoration of cervical class V
cavities and permit isolation of an anterior tooth during endodontic treatment.
✔✔Pediatric dental dam clamps - ✔✔Clamps for primary teeth are designed to
accommodate the smaller sizes and shape of the primary teeth or partially erupted
permanent teeth. Clamps for primary teeth are available in sizes 00, W00, and 2.
✔✔Ligatures on clamps - ✔✔Dental floss or dental tape should always be attached to
the bow of the dental dam clamp as a ligature before the clamp is placed in the pt's
mouth. The ends should always be kept out of the pt's mouth on the outside of the dam
and within easy reach.
✔✔Dental dam stabilizing cord - ✔✔A disposable latex cord that is an alternative to the
conventional clamp method of securing the dental dam in which during insertion, the
cord is stretched so that it becomes narrow and then placed interproximally to secure
the dental dam material
✔✔Factors included in dental dam preparation - ✔✔- maxillary or mandibular arch
- shape of the arch
- any irregularities, such as missing teeth, a fixed prosthesis, or malpositioned teeth
- teeth to be isolated
- identification of the anchor tooth and location of the keypunch hole
- size and spacing of the other holes to be punched
✔✔Anchor tooth for dental dams - ✔✔Holds the dental dam clamp, and the keypunch
hole covers the anchor tooth.
✔✔Maxillary arch dental dam application - ✔✔Stamp or mark dental dam material and
punch holes.
Because the holes for maxillary anterior teeth are punch 1 inch down from the upper
edge of the dam, it is helpful to stamp or make the extension in the back of the punch
plate of the dam punch to indicate 1 inch. This mark designates the margin of the dam
for these holes.
✔✔Mandibular arch dental dam application - ✔✔Dam is stamped or marked and holes
are punched, leaving a 2 inch margin from the edge.
Because of the smaller size of mandibular teeth, the holes are punched closer together
than for posterior teeth. Use a water soluble Subaru ant if crowding or tight contacts are
noted.
✔✔Curve of the arch effect in dental dam - ✔✔It may be necessary to make
adjustments to punching the dam to accommodate an extremely narrow or wide arch. If
,not, there will be difficulty with isolation, causing inversion of the edges of the holes of
the dam.
Bunching or stretching lingually can occur if the curve of the arch is punched too flat or
too wide.
Folding and stretching of the dam on the facial aspect occurs if the arch is punched too
curved or too narrow.
✔✔Misaligned teeth effect in dental dam - ✔✔If the tooth is lingually malposed, the
hole-punch size remains the same, but the hole is placed about 1 mm lingually from the
normal arch alignment.
If the tooth is facially malposed, the hole punch size remains the same, but the hole is
placed about 1 mm facially from the normal arch alignment.
✔✔Teeth to be isolated for dental dam placement - ✔✔Single tooth isolation is typically
used for selective restorative procedures and for endodontic treatment. Some dentist's
isolate only the tooth to be treated; others prefer to have 2 teeth isolated so that the
second tooth acts as an anchor tooth to hold the clamp. During treatment in the
posterior area, this second tooth provides greater stability and better visibility.
For multiple tooth isolation, 3 or 4 teeth— or for optimum stability, 6-8 teeth—- are
isolated to counteract the pull on the dam that is created by the curvature of the teeth in
the arch. At least one tooth posterior to the tooth being treated should be isolated.
When maxillary anterior teeth are to be isolated, maximum stability is achieved by
isolating the 6 anterior teeth (canine to canine).
✔✔Keypunch hole for dental dam - ✔✔The anchor tooth holds the dental dam clamp,
and the keypunch hole is punched in the dental dam to cover the anchor tooth.
The largest hole (#5) is necessary for the keypunch because it also must accommodate
the clamp.
For maximum stability and ease of access, the keypunch hole is placed one or two teeth
distal to the tooth that is receiving treatment.
✔✔Dental dam hole sizing and spacing - ✔✔It is important to have the correct sizing to
allow the dam to slip easily over the tooth and fit snugly in the cervical area; this
prevents leakage around dam.
In general, the holes are spaced with 3.0 to 3.5 mm between the edges, not the centers,
of the holes. This allows adequate spacing between the holes to create a septum that
can slip between the teeth without tearing or injuring the gingiva.
, The septum is the dental dam material between the holes of the punched dam. During
application, this portion of the dam is passed between the contacts.
✔✔Troubleshooting hole sizing and spacing - ✔✔If the holes are too large, the dam will
not fit tightly around the tooth. This may allow saliva to leak through the hole.
If the holes are too small, the dam will not slip easily over the tooth. This may cause the
dam to stretch or tear and may leave the gingiva exposed.
If the holes are too close, the dam may tear or stretch. The stretched holes may leave
the gingiva exposed and may cause leakage.
If the holes are too far apart, excess material is present between the teeth. This may
block the dentist's vision or catch the instrumentation.
✔✔Dental dam placement methods - ✔✔Two methods are used for dental dam
placement. The main difference is the sequencing in placement of the clamp and the
dam. The remaining steps are the same.
In the one step method, the dam and the clamp are placed at the same time.
In the two step method, first the clamp is placed and then the dental dam material is
stretched over it.
✔✔Anterior teeth dental dam application - ✔✔The isolation of anterior teeth occurs
typically from canine to canine. When the isolation is complete, a dental dam clamp is
not required. The dental dam will remain secure with placement of dental tape or with
stretching of a small corner of the dental dam interproximal lay between the canine and
the first premolar on each side.
A cervical or anterior clamp may be required if the gingival third of a tooth is to be
restored and if the gingival tissue must be retracted for better exposure. The jaws of this
clamp are positioned lightly on the cementum of the root, just below the carious lesion.
Occasionally, additional stabilization of the cervical clamp is necessary. Softened stick
compound may be used for this purpose. A heat source such as a butane torch or a
Bunsen burner is needed.
✔✔Stabilizing the cervical clamp for the dental dam - ✔✔- soften the red or green stick
compound by holding it over a flame until the tip bends, then place the tip in hot water
for 5 seconds
- twist off approximately 1 inch of the tip, and shape it into a cone
- very carefully reheat the cone of the compound in the flame, then place the softened
compound under the bow of the clamp (occlusal surface), away from the area to be
treated
- repeat this procedure for the second bow on the opposite side of the clamp
SOLUTIONS RATED A+
✔✔Dental dam clamps - ✔✔The dental dam clamp is the primary means of anchoring
and stabilizing the dental dam.
Clamps are made of chrome or nickel-plated steel and are designed to hold the dental
dam securely at the end nearest the tooth that is being treated.
The opposite end of the dental dam application will also be stabilized, and this is
accomplished w the use of either another clamp, a dental dam stabilizing cord, or dental
floss or tape. This technique is known as ligating the dam.
✔✔Parts of the dental dam clamp - ✔✔The parts of the clamp that are important to
identify are the bow and the jaws.
The bow is the rounded portion of the clamp that extends through the dental dam. The
clamp is always positioned on the tooth so that the bow is located at the distal aspect.
The jaws encircle the tooth and are shaped into four prongs. All four prongs must be
firmly seated on the tooth to create facial to lingual balance necessary to stabilize the
clamp. A hole is located on each side of the jaw of the clamp. The beaks of the dental
dam forceps fit into these holes to allow placement and removal of the clamp.
A winged clamp "W" is designed with extra extensions to help retain the dental dam.
Wingless clamps have numbers/letters that begin w the letter W and do not have extra
projections to engage the clamp.
✔✔Fitting the dental dam clamp - ✔✔Jaws of the clamp are designed to fit the cervical
area of the tooth below the height of contour and at, or slightly below, the
cementoenamel junction. The height of contour is the widest point on the facial and
lingual contours of the tooth.
The clamp must be positioned with all 4 prongs firmly in place on the tooth before the
clamp forceps are loosened. If the clamp is not placed properly, it may spring off.
✔✔Posterior dental dam clamps - ✔✔Used for the maxillary and mandibular posterior
teeth.
These clamps are universal, meaning the same clamp can be placed on the same type
of tooth in the opposite quadrant.
Clamps 7 and W7 are universal mandibular molar clamps, and clamps 8 and W8 are
universal maxillary molar clamps.
,✔✔Anterior dental dam clamps - ✔✔Such as clamps 9 and W9, are designed, to retract
the gingiva on the facial surface, improve visibility for the restoration of cervical class V
cavities and permit isolation of an anterior tooth during endodontic treatment.
✔✔Pediatric dental dam clamps - ✔✔Clamps for primary teeth are designed to
accommodate the smaller sizes and shape of the primary teeth or partially erupted
permanent teeth. Clamps for primary teeth are available in sizes 00, W00, and 2.
✔✔Ligatures on clamps - ✔✔Dental floss or dental tape should always be attached to
the bow of the dental dam clamp as a ligature before the clamp is placed in the pt's
mouth. The ends should always be kept out of the pt's mouth on the outside of the dam
and within easy reach.
✔✔Dental dam stabilizing cord - ✔✔A disposable latex cord that is an alternative to the
conventional clamp method of securing the dental dam in which during insertion, the
cord is stretched so that it becomes narrow and then placed interproximally to secure
the dental dam material
✔✔Factors included in dental dam preparation - ✔✔- maxillary or mandibular arch
- shape of the arch
- any irregularities, such as missing teeth, a fixed prosthesis, or malpositioned teeth
- teeth to be isolated
- identification of the anchor tooth and location of the keypunch hole
- size and spacing of the other holes to be punched
✔✔Anchor tooth for dental dams - ✔✔Holds the dental dam clamp, and the keypunch
hole covers the anchor tooth.
✔✔Maxillary arch dental dam application - ✔✔Stamp or mark dental dam material and
punch holes.
Because the holes for maxillary anterior teeth are punch 1 inch down from the upper
edge of the dam, it is helpful to stamp or make the extension in the back of the punch
plate of the dam punch to indicate 1 inch. This mark designates the margin of the dam
for these holes.
✔✔Mandibular arch dental dam application - ✔✔Dam is stamped or marked and holes
are punched, leaving a 2 inch margin from the edge.
Because of the smaller size of mandibular teeth, the holes are punched closer together
than for posterior teeth. Use a water soluble Subaru ant if crowding or tight contacts are
noted.
✔✔Curve of the arch effect in dental dam - ✔✔It may be necessary to make
adjustments to punching the dam to accommodate an extremely narrow or wide arch. If
,not, there will be difficulty with isolation, causing inversion of the edges of the holes of
the dam.
Bunching or stretching lingually can occur if the curve of the arch is punched too flat or
too wide.
Folding and stretching of the dam on the facial aspect occurs if the arch is punched too
curved or too narrow.
✔✔Misaligned teeth effect in dental dam - ✔✔If the tooth is lingually malposed, the
hole-punch size remains the same, but the hole is placed about 1 mm lingually from the
normal arch alignment.
If the tooth is facially malposed, the hole punch size remains the same, but the hole is
placed about 1 mm facially from the normal arch alignment.
✔✔Teeth to be isolated for dental dam placement - ✔✔Single tooth isolation is typically
used for selective restorative procedures and for endodontic treatment. Some dentist's
isolate only the tooth to be treated; others prefer to have 2 teeth isolated so that the
second tooth acts as an anchor tooth to hold the clamp. During treatment in the
posterior area, this second tooth provides greater stability and better visibility.
For multiple tooth isolation, 3 or 4 teeth— or for optimum stability, 6-8 teeth—- are
isolated to counteract the pull on the dam that is created by the curvature of the teeth in
the arch. At least one tooth posterior to the tooth being treated should be isolated.
When maxillary anterior teeth are to be isolated, maximum stability is achieved by
isolating the 6 anterior teeth (canine to canine).
✔✔Keypunch hole for dental dam - ✔✔The anchor tooth holds the dental dam clamp,
and the keypunch hole is punched in the dental dam to cover the anchor tooth.
The largest hole (#5) is necessary for the keypunch because it also must accommodate
the clamp.
For maximum stability and ease of access, the keypunch hole is placed one or two teeth
distal to the tooth that is receiving treatment.
✔✔Dental dam hole sizing and spacing - ✔✔It is important to have the correct sizing to
allow the dam to slip easily over the tooth and fit snugly in the cervical area; this
prevents leakage around dam.
In general, the holes are spaced with 3.0 to 3.5 mm between the edges, not the centers,
of the holes. This allows adequate spacing between the holes to create a septum that
can slip between the teeth without tearing or injuring the gingiva.
, The septum is the dental dam material between the holes of the punched dam. During
application, this portion of the dam is passed between the contacts.
✔✔Troubleshooting hole sizing and spacing - ✔✔If the holes are too large, the dam will
not fit tightly around the tooth. This may allow saliva to leak through the hole.
If the holes are too small, the dam will not slip easily over the tooth. This may cause the
dam to stretch or tear and may leave the gingiva exposed.
If the holes are too close, the dam may tear or stretch. The stretched holes may leave
the gingiva exposed and may cause leakage.
If the holes are too far apart, excess material is present between the teeth. This may
block the dentist's vision or catch the instrumentation.
✔✔Dental dam placement methods - ✔✔Two methods are used for dental dam
placement. The main difference is the sequencing in placement of the clamp and the
dam. The remaining steps are the same.
In the one step method, the dam and the clamp are placed at the same time.
In the two step method, first the clamp is placed and then the dental dam material is
stretched over it.
✔✔Anterior teeth dental dam application - ✔✔The isolation of anterior teeth occurs
typically from canine to canine. When the isolation is complete, a dental dam clamp is
not required. The dental dam will remain secure with placement of dental tape or with
stretching of a small corner of the dental dam interproximal lay between the canine and
the first premolar on each side.
A cervical or anterior clamp may be required if the gingival third of a tooth is to be
restored and if the gingival tissue must be retracted for better exposure. The jaws of this
clamp are positioned lightly on the cementum of the root, just below the carious lesion.
Occasionally, additional stabilization of the cervical clamp is necessary. Softened stick
compound may be used for this purpose. A heat source such as a butane torch or a
Bunsen burner is needed.
✔✔Stabilizing the cervical clamp for the dental dam - ✔✔- soften the red or green stick
compound by holding it over a flame until the tip bends, then place the tip in hot water
for 5 seconds
- twist off approximately 1 inch of the tip, and shape it into a cone
- very carefully reheat the cone of the compound in the flame, then place the softened
compound under the bow of the clamp (occlusal surface), away from the area to be
treated
- repeat this procedure for the second bow on the opposite side of the clamp
