Restorative - Outcome 5

Question 1

To protect the too/teeth from moisture, debris and maintain a dry environment for the placement of dental materials the following characteristics should be met when choosing an isolation technique:

Answer 1

• Easy to apply
• Protects hard and soft surfaces
• Comfortable for the patient
• Retraction that provides better visualization for the operator
• Prevents moisture contamination
• Isolation of the area of concern

Question 2

The three most common isolation techniques used in dentistry are:

Answer 2

Cotton-roll
Dry-angle
Dental dam

Question 3

Cotton-Roll Isolation

Answer 3

This type of isolation uses rolls of tightly formed absorbent cotton that are pre-shaped to be positioned close to the salivary ducts. The cotton rolls are positioned to absorb the saliva flow and excess water.

Advantages:
Easy application
No additional equipment is required.
Flexible, permitting adaptation to different areas of the mouth

Disadvantages:
Does not provide complete isolation
Does not protect the patient from aspiration
May stick to the oral mucosa. If removed improperly can cause irritation.
Must be replaced frequently because of saturation
Has limited retraction

Cotton rolls are placed with cotton forceps or using specially designed holders. On the maxillary, they are placed in the buccal mucosa adjacent to the second molar buccal surfaces to absorb moisture from the parotid duct (Stensen’s duct).

In the mandibular, they are placed just under the tongue lingual to the mandibular anterior teeth by the submandibular duct (Wharton’s duct). Another cotton roll is often placed in the buccal vestibule on the mandibular to aid in retraction as well as moisture control.

Question 4

Dry-Angle Isolation

Answer 4

Dry angles are triangular cotton pads that placed along the buccal mucosa as an alternate isolation technique to block the parotid duct (Stensen’s duct) when working the posterior teeth in both the maxillary and mandibular arches. The dry angle blocks the flow of saliva and protects the tissues in this area from injury caused by the dental bur or other instruments used during the procedure.

Some dry angles have a silver coating on one side to reflect light into the operative field. The reflective side faces toward the oral cavity.

Follow the manufacturer’s instructions for correct placement. Use cotton pliers/forceps. If the dry angle becomes soaked during the procedure, replace it. Soaking the pad with water lets, you easily remove and separate it from the tissues.

Question 5

The Dental Dam

Answer 5

The dental dam is a thin stretchable rubber-like material that acts as a barrier applied to selected teeth. When the dam is properly placed, the isolated teeth are the only teeth exposed or visible in the operative field. This allows a clearer field of vision for the operator to the restorative site. The rubber-like material can be made from a latex rubber material or a silicone latex-free material. Checking the medical history before using a dental dam is very important as many patients have a latex allergy and the non-latex dam must be used.

Question 6

Indications for dental dam:

Answer 6

-Serves as an essential infection control barrier in the preparation of teeth
-Safeguards the patient’s mouth against constant debris, dental materials, or other liquids
-Protects accidental aspirating or swallowing debris
-Protects the tooth from contamination by saliva or debris if pulpal exposure occurs
-Protects the oral cavity from exposure when an infected tooth is open during endodontic treatment
-Provides moisture control that is essential for placement of restorative materials
-Improves access by retracting the lips, tongue, and gingiva
-Provides better visibility because of the contrasting colors of the dam and tooth
-Increases dental team efficiency by discouraging patient conversation, reducing the time required

Question 7

Contraindications for dental dam

Answer 7

Physical conditions may cause discomfort for the patient, such as asthma, nasal congestion, or lesions around the area of placement.
Patient concerns such as claustrophobia.
Conditions in the mouth such as mobile teeth, partially erupted teeth, or severe misalignment of teeth

Question 8

The Dental Dam

Answer 8

-A thin piece of rubber-like material placed over the teeth for isolation.
-Latex or latex-free material
-Size: available in a continuous roll or in two precut sizes (6 × 6 inches for adults and 5 × 5 inches for children)
-Colour: available in a wide range, from light to dark (dark is preferred because of the contrast to tooth structure)
-Available in various scents and flavors
-Thickness: three thicknesses (gauges): thin (light), medium (most common), and heavy
-A thin dental dam is most frequently used in endodontic applications because only one tooth is isolated and minimal stretching of the material occurs.
-The medium-thickness dam is used in most restorative procedures because it is easy to handle and can be used to isolate selected teeth.
-A heavy dental dam is used when tissue retraction and extra resistance to tearing are required, or when there are very tight contacts.

Question 9

The Dental Dam Clamp

Answer 9

The clamp is the primary means of anchoring a dental dam. The clamps are made of chrome- or nickel-plated steel and can be sterilized and reused. Dental dam clamps are available in many sizes and designs to accommodate different needs. The jaws are designed to fit the cervical area, or collar, of the tooth. Parts of the clamp include;

Bow: a rounded portion of the clamp, always positioned to the distal aspect
Jaws: prongs that seat around the tooth create the extension and balance necessary to stabilize the clamp
Points: all four points must be in contact with the anchor tooth below the height of contour for stability.
Forceps Holes: the beaks of the dental dam forceps fit into these holes to allow placement and removal of the clamp.

Question 10

Dental Dam Forceps

Answer 10

Dental dam forceps have two-narrow prongs on the working end of the instrument. The prongs fit into the clamp holes to expand or contract the clamp for application and removal from the anchor tooth.

Question 11

Dental Dam Punch

Answer 11

A dental dam punch is a precision instrument with a rotating disc, containing holes of various sizes and an opposing sharp stylus to cut cleanly through the dental dam.

Question 12

Dental Dam Napkin

Answer 12

A cotton napkin designed to fit over the face to prevent irritation from the dam and to absorb moisture.

Question 13

Dental Dam Frame

Answer 13

A frame is a u-shaped instrument with prongs to stabilize the rubber in position on the patient’s face. Frames are available in plastic and metal. Note: Use a plastic frame in procedures that need an x-ray, such as endodontic procedures.

Question 14

Tucking Instrument

Answer 14

A blunt-ended instrument used to invert or turn the edge of the rubber dam around the cervical margin of the tooth to prevent leakage and maintain a dry working field.

Black spoon excavator
Burnisher
Plastic filling instrument

Question 15

Ligatures on Clamps

Answer 15

Dental floss should be attached to the dental dam clamp before it is placed in the patient’s mouth.
The ligature makes it possible to retrieve a clamp if it become dislodged.
Ends of the ligature are kept on the outside of the patient’s mouth and within easy reach. The ligature is attached to the dental dam frame to keep it available and out of the way of the operator.

Question 16

Lubricant (for dental dam)

Answer 16

A water-soluble lubricant used on the patient’s lips and on the underside of the dam to make it easier to slip over the teeth (if tight contacts exist). Note: Petroleum jelly (Vaseline) is not a water-based lubricant and can interfere with the setting of some dental materials and will break down latex material.

Question 17

Cotton Tipped Applicator (CTA)

Answer 17

The CTA is used to apply the lubricant to the dam material or on the patient’s lips.

Question 18

Scissors (for Dental Dam)

Answer 18

Use scissors to cut interproximal septums of the dental dam to facilitate smooth removal of the dam.

Question 19

Basic Three Instruments (for Dental Dam)

Answer 19

Mirror, explorer and cotton forceps

Question 20

What to consider when choosing the dental dam clamps

Answer 20

Many different sizes and designs of dental dam clamps are available to accommodate different needs. The shape of the tooth being clamped, the procedure being preformed as well as the location in the mouth all play a role in determining which clamp is best suited for the situation. It is the dental assistants role to understand which type of clamp will work best for each situation.

Question 21

Preparing (punching) the Dental Dam

Answer 21

The dental dam must be prepared according to dentist preference, tooth or teeth involved and the procedure to be completed. When planning where to punch the holes in the dam, the following must be considered;

Maxillary or mandibular arch
The shape of the arch
Teeth to be isolated
Any irregularities, such as missing teeth, mobile teeth, diastemas, a fixed prosthesis, or malaligned teeth
Identification of the anchor tooth and location of the keypunch hole
Size and spacing of the other holes to be punched
The dental dam punch has a punch table or plate with different-sized holes and rotates to allow using different holes for different sized teeth. The table is rotated so the stylus lines up with the hole selected to punch.

Question 22

Punching the Holes

Answer 22

Holes are punched according to the shape of the arch, with approximately 3 - 3.5 mm of dam left between holes.
If any teeth are missing in the operating field, the holes for these teeth should be skipped and the operating field adjusted as necessary.
If any teeth in the operating field are out of alignment, the holes punched for these teeth should be offset to approximate the misalignment.
Each Hole in the punch-cutting table is associated with specific teeth, as follows:

Mandibular incisors
Maxillary incisors
Premolars and cuspids
Molar teeth
Anchor tooth
Examine the tooth to be clamped, and select the hole size that will accommodate both the tooth and the clamp. For molars, you may have to use the largest hole, plus an extra punch of material along the side.
Punch the hole and be sure the stylus has completely cut the dam.
Continue to punch the arch using the table as a guide to select the hole size
Note: Each hole in the dental dam must be punched cleanly. An incorrectly punched hole will cause the dam to tear.

Question 23

Clamp Selection and Preparation

Answer 23

A clamp is used to anchor and help hold the rubber dam securely in place. In order to be secure, a clamp must be placed on the anchor tooth below the area of the greatest circumference of the tooth. If the clamp is to fit securely, all four points of the jaws of the clamp must contact the anchor tooth at the cementoenamel junction (CEJ).

Question 24

7 or W7 “W” indicates wingless - clamp

Answer 24

Normally erupted mandibular molar - The jaws of the #7 clamp are long and flat. They are shaped to fit a mandibular molar, which is inclined to be square in form

Question 25

W3 - clamp

Answer 25

Small mandibular molar -The jaws of the #3 are smaller than the #7 and more rounded in shape

Question 26

W8 - clamp

Answer 26

Normally erupted maxillary molar - The jaws of the #8 clamp are adaptable for a maxillary molar, which tends to be round in form. The inner part of the jaws of the #8 clamp curve downward to firmly grip a maxillary molar below the height of contour

Question 27

W8A or 8A - clamp

Answer 27

Small maxillary or mandibular molars - The smaller size and the reduction of the curvature of the jaws render the #8A clamp adaptable for smaller, partially erupted molars

Question 28

W2A or 2A - clamp

Answer 28

Maxillary or mandibular small bicuspids - The jaws of the #2A clamp extend downward to firmly grip the bicuspid beneath the gingiva

Question 29

W2 or 2 - Clamp

Answer 29

Maxillary or mandibular large bicuspids - The small, flat jaws of the #2 clamp render it adaptable for anchoring the rubber dam to a bicuspid

Question 30

12A - Clamp

Answer 30

Mandibular right molars/ Maxillary left molars - These clamps have serrated jaws which provide stability over a wide range of conditions, including partially erupted teeth

Question 31

13A - clamp

Answer 31

Mandibular left molars/ Maxillary right molars - These clamps have serrated jaws which provide stability over a wide range of conditions, including partially erupted teeth

Question 32

W14A or 14A - Clamp

Answer 32

Maxillary or mandibular molar, which has only partially erupted. - The jaws of the #14A clamp extend downward to firmly grip the partially erupted molar beneath the gingival. These clamps are slightly larger in size than the #8A

Question 33

Clamp preparation

Answer 33

After dental dam clamps have been used and sterilized several times, they tend to become brittle and may snap in half when they are stretched open by the forceps. To avoid the potential of the patient aspirating on the clamp, two pieces of floss must be tied to the holes on each side of the clamp.

Question 34

Procedure for placing a ligature on the clamp:

Answer 34

Cut two pieces of floss, 25 inches or 62 ½ centimeters in length.
Fold the floss in half and thread the loop end through the hole in the clamp.
Pull the free ends of the floss through the loop and pull tight.
When applying the clamp to the tooth, hold the clamp in the forceps and wrap the free ends of both pieces of floss around the baby finger of the hand holding the forceps.
If at any time during the application of the dam, you feel uncertain about the clamp stability, have your patient hold the free ends of the floss.

Once the dam and frame have been placed, these pieces of floss, (ligatures), are tied around the frame to ensure the clamp is anchored outside of the mouth