1. Moisture Control Chapter 36 1
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2. Chapter 36 Lesson 36.1
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3. Learning Objectives Define and spell the Key Terms.
List isolation techniques used to decrease moisture during a dental procedure.
Describe the two types of oral evacuation systems used in dentistry.
Describe the grasp and positioning of the tip of the high-volume evacuator (HVE).
(Cont’d)
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4. Learning Objectives
(Cont’d)
Demonstrate the grasp and positioning of the HVE during a procedure.
Discuss the use of the air-water syringe.
Perform limited and full-mouth rinses.
Place cotton rolls for isolation.
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5. Moisture Control
The objective is to maintain an intraoral environment that keeps the operating field free of excess water, saliva, blood, tooth fragments, and excess dental materials.
One of the most important responsibilities of the dental assistant is to maintain moisture control during a procedure.
Why is moisture control so important?
The term “oral evacuation” describes the process of removing excess fluids from the mouth.
When is an oral evacuator used? (Before, during, and after a dental procedure.)
The saliva ejector and high-volume evacuator are the two types of evacuators used in dentistry.
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6. Saliva Ejector
Small strawlike oral evacuator used for less invasive dental procedures
Indications for use:
Preventive procedures such as prophylaxis, fluoride treatments, and sealant placement
Helps control saliva and moisture accumulation under the dental dam
For the cementation of a crown or bridge
During an orthodontic bonding procedure
What is the main function of the saliva ejector? (Removes liquids from the mouth; not powerful enough to remove debris.)
The saliva ejector is made of a soft plastic tubing that can be shaped and easily placed in the oral cavity.
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7. Placement of Saliva Ejector
Bend and shape the saliva ejector for stationary placement.
Position the ejector under the tongue.
Position the ejector opposite the side on which the dentist is working.
Hold the saliva ejector throughout the procedure, repeatedly sweeping the mouth to remove fluids, or position the suction in the mouth during a procedure.
When the saliva ejector is stationary, bend it into the shape of a candy cane. This shape permits easy placement under the tongue.
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8. Fig Saliva ejector.
Place the saliva ejector cautiously to avoid traumatizing soft tissue (e.g., floor of the mouth, frenums, mucosa).
What common dental item can be used as a buffer to help avoid trauma? (Cotton roll.)
Instruct the patient to avoid closing down on the saliva ejector and clamping off the vacuum suction.
Tell the patient not to close the lips around the saliva ejector during suctioning.
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9. High-Volume Evacuator
Used for most dental procedures, especially when the dental handpiece is in use
Indications for use
Keeps the mouth free of saliva, blood, water, and debris
Retracts the tongue and cheek from the field of operation
Reduces bacterial aerosol caused by the high-speed handpiece
The HVE, also known as the oral evacuator, works on a vacuum system.
It is stronger than the saliva ejector and can remove debris because a high volume of air is moved into the vacuum hose.
Two types of HVE tips are available. Each is designed for specific dental procedures.
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10. Types of HVE Tips Operative-suction tips Surgical-suction tips
Designed with a straight or slight angle in the middle
Beveled working end
Made of durable plastic or stainless steel
Surgical-suction tips
Much smaller in circumference
Made of stainless steel
Name an advantage and a disadvantage of a plastic operative tip. (Advantage: disposable; disadvantage: cost.)
Why does the surgical tip have a smaller circumference? (So it can operate within the limited space and visibility of a surgical site.)
What is the main function of the surgical tip? (Removes blood, tissue, and debris instead of large amounts of water and fluids.)
The stainless-steel tip is part of the surgical setup tray.
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11. Fig. 36-4 Grasps used for operating the HVE
Fig Grasps used for operating the HVE. Top, thumb-to-nose grasp; bottom, pen grasp.
Describe the two HVE grasps pictured in the slide. (Top: thumb-to-nose grasp; bottom: pen grasp.)
Both methods enable the dental assistant to control the tip.
Why is it important to control the tip? (For placement and to assure patient comfort and safety.)
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12. Guidelines for Positioning the HVE
Place the evacuator before the dentist positions the handpiece and mouth mirror.
Position the HVE on the surface of the tooth closest to you.
Position the tip as close as possible to the tooth being worked on.
Position the bevel of the tip so that it is parallel to the tooth surface.
Keep the edge of the tip even or slightly beyond the occlusal or incisal edge.
Depending on how much the tissue resists retraction and on the area being treated, you may want to reduce dental-assistant fatigue by changing the position of the evacuator.
In which hand does the dental assistant hold the evacuator tip when assisting a right-handed dentist? (Right hand.)
Hold the evacuator tip in the left hand when assisting a left-handed dentist.
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13. Fig. 36-5 Operator and assistant positions in high-volume evacuation.
The efficiency and effectiveness of the procedure depends on timing when suction is needed, when the HVE is positioned, and when to remove the suction tip.
Notice how the suction tip is close to the working end of the handpiece.
Why should the dental assistant position the HVE close to the handpiece? (To catch water spray and debris before it collects in the patient’s mouth.)
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14. The Air-Water Syringe
Used for convenience and accuracy to complete the rinsing process
Guidelines for use
Direct the tip toward the tooth being worked on.
Keep a close distance between the operative site and the syringe tip.
Use air on the mouth mirror continuously when indirect vision is involved.
When you hear the handpiece stop, it’s time to rinse and dry the site.
When completing a limited area or full-mouth rinse, move the tip while spraying the area.
Use the air-water syringe to increase visibility of the treatment area.
The air-water syringe is attached to the dental unit; it directs air, water, or both through a small, sterile metal tip or plastic disposable tip.
Rinsing also removes debris from the patient’s mouth before dismissal.
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15. Rinsing the Oral Cavity
Maintains a clear operating field for the dentist and keeps the patient comfortable
Two types of rinsing procedures
Limited-area rinsing
Performed frequently throughout a procedure
Accomplished quickly and efficiently
Full-mouth rinse
Freshens the patient's entire mouth
Completed at the end of a procedure
Perform limited rinsing quickly and efficiently, without delaying the procedure, when the dentist exits the mouth and pauses for inspection.
When the assistant is alone and rinsing the entire mouth, he or she can use the saliva ejector as an alternative to the HVE.
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16. Isolation of Teeth Criteria for Isolation Techniques Easy to apply
Safe for soft and hard tissues
Comfortable for the patient
Provides retraction for better visualization for the operator
Prevents moisture contamination
Isolates the area of concern
For best results during a dental procedure, keep the area being treated dry and isolated from its normal environment.
Why is isolation so important? (The area or tooth being treated should be kept free from contaminants such as saliva, blood, and debris to help prevent infection from a failed restoration.)
What are the three most common isolation techniques used in dentistry? (Cotton-roll isolation, dry-angle isolation, and dental dam placement.)
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17. Cotton-Roll Isolation
Advantages
Easy application
No additional equipment 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
Must be replaced frequently because of saturation
Limited retraction
Rolls of tightly formed absorbent cotton are preshaped to be positioned close to the salivary ducts.
The cotton rolls are positioned to absorb the saliva flow and excess water.
What is the best way to place or remove a cotton roll from the patient’s mouth? (With the use of cotton pliers or forceps.)
Use cotton-roll holders, which are designed to hold multiple cotton rolls more securely, in the mandibular areas.
Can you think of a time when cotton-roll holders would be needed most? (When the operator is working alone.)
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18. Fig. 36-6 Cotton-roll isolation in the mandibular quadrant.
Knowing the location of salivary ducts is important in controlling moisture properly.
Where are the salivary ducts on the maxillary arch, and what are they called? (The ducts are located in the buccal mucosa adjacent to the maxillary second molar buccal surfaces. These bilateral ducts are called the Stensen ducts.)
Where is the salivary duct on the mandibular arch located, and what is it called? (The duct is located just under the tongue lingual to the mandibular anterior teeth. This duct is called the Wharton duct.)
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19. Dry-Angle Isolation
A triangular absorbent pad placed over the Stensen duct blocks the flow of saliva and protects the tissues in this area.
Instead of placing a cotton roll along the buccal mucosa as an isolation technique, place a dry angle.
This pad helps isolate the posterior teeth in both the maxillary and mandibular arches.
Place the dry angle on the buccal mucosa over the Stensen duct.
What are the two functions of the dry angle? (Blocking the flow of saliva and protecting the tissues in this area from injury caused by the dental bur or other instruments.)
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20. Fig. 36-8 Dry-angle placement in the buccal mucosa.
Remember to follow the manufacturer’s instructions for placement.
If the dry angle becomes soaked during the procedure, it may need to be replaced several times.
Soaking the pad with water lets you easily remove and separate it from the tissues (buccal mucosa).
Use the cotton pliers/forceps to replace the dry angle.
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21. Chapter 36 Lesson 36.2
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22. Learning Objectives
Describe the dental dam and its role in moisture control.
List the equipment and supplies for dental dam application.
Identify the equipment and supplies used for dental dam application.
(Cont’d)
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23. Learning Objectives
(Cont’d)
Describe the special preparation and placement of the dental dam.
Have the dental dam prepared correctly for a procedure.
Place the dental dam as an expanded function.
Remove the dental dam as an expanded function.
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24. The Dental Dam
A thin stretchable latex material that acts as a barrier when appropriately applied to selected teeth.
When the dam is in place, only selected teeth are visible through the dam.
What are these isolated teeth called? (Isolated or exposed teeth.)
The dam is placed after local anesthesia is administered and before the procedure begins.
Use caution when using the dam on a patient who is allergic to latex; make sure that the dam is latex-free.
(Cont’d)
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25. The Dental Dam Indications for use Infection-control barrier
(Cont’d)
Indications for use
Infection-control barrier
Safeguard for the patient's mouth
Protection from accidental inhalation or swallowing of debris
Protection from contamination for the tooth
Moisture-control device
Tool with which to improve access
Tool with which to improve visibility
Tool with which to increase dental-team efficiency
The dental dam can be placed in about 2 minutes.
The dental dam keeps debris from the preparation or treatment area away from the rest of the mouth.
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26. Dental Dam Material Dental dam materials Latex or latex-free material
Available in a continuous roll or in two precut sizes (6 × 6 inches for adults and 5 × 5 inches for children)
Available in a wide range of colors, from light to dark (dark is preferred because of the contrast)
Available in various scents and flavors
Three thicknesses (gauges): thin (light), medium, and heavy
Thin dam materials are most used frequently in endodontic applications because only one tooth is isolated at a time and minimal stretching of the material occurs.
The medium-thickness dame is used in operative procedures because it is easy to handle and can be used to isolate selected teeth.
Use heavy materials when tissue retraction and extra resistance to tearing are required. Also use a heavier dam when you must isolate teeth with tight contacts.
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27. Fig. 36-9 Dental dam material
Fig Dental dam material. (From Boyd L: Dental instruments: a pocket guide, ed 3, St Louis, 2009, Saunders.)
Many dental manufacturers and dental supply companies have dental dam materials available.
Consider several factors when purchasing dental dam materials: cost, quality, availability, and compatibility with dental dam napkins, lubricants, the dental dam punch, the dental dam forceps, and the dental dam frame.
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28. Dental Dam Frame
Stabilizes and stretches the dam so it fits tightly around the teeth and out of the operator's way
Available in various plastic and metal frames
U-shaped frame
Young frame
Otsby frame
The dental dam frame is a necessary component for f dental dam placement.
Both plastic and metal frames can be sterilized and reused.
The plastic U-shaped frame is radiolucent, so it’s not necessary to remove it before radiograph exposure. The frame is placed under the dam material.
The Young frame is placed on the outside of the dam. Patients are more comfortable with this frame.
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29. Fig Dental dam frames. (From Boyd L: Dental instruments: a pocket guide, ed 3, St Louis, 2009, Saunders.)
Identify the two common dental dam frames in the slide. (Both are U-shaped frames. The first is the metal Young U-shaped frame, and the second is a plastic U-shaped frame.)
The sharp projections hold the dental dam material in place.
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30. Additional Dental Dam Equipment
Dental dam napkin
Increases patient comfort by absorbing moisture between the patient's face and the dam
Lubricant
Water-soluble lubricant placed on the underside of the dam to help the dam material slide over the teeth and through the interproximal spaces.
Can you think of another advantage to using a dental dam napkin? (It keeps the patient’s face from coming into contact with the dental dam material, which could cause skin irritation.)
Two dental dam lubricants may be used. One is used on the patient’s lips to ensure patient comfort. The second is used to help the dam materials slide between the interproximal spaces without tearing or ripping.
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31. Dental Dam Punch
Creates the holes in the dental dam that are needed to expose the teeth to be isolated
The working end of the dental punch has an adjustable stylus.
What is a stylus? (Cutting tip.)
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32. Fig Dental dam punch.
Notice how the punch plate is a rotary plate form with five or six holes of different sizes cut into the face of the plate.
These holes are approximately 1 mm deep, with sharp edges to accommodate the stylus.
Use caution to make sure that the holes are cut cleanly. A hole with a ragged edge may tear easily when forced into an interproximal space during isolation of a tooth. Ragged edges on the holes may also irritate the gingiva.
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33. Fig Size of holes for punching the dental dam and the coordinating teeth for the size of punched holes. (Adapted from Baum L, Phillips RW, Lund MR: Textbook of operative dentistry, ed 3, Philadelphia, 1995, Saunders.)
The punch-plate holes, numbered 1 (the smallest) through 5 (the largest), fit around different sizes of objects as follows:
1: Fits the mandibular anterior teeth
2: Fits the emaxillary anterior teeth
3: Fits mandibular and maxillary premolars
4: Fits larger teeth such as molars
5: Used to create the hole that fits over the dental dam clamp
How do you know where to punch the holes on the dental dam material? (The dental dam stamp and template will guide the positioning of the holes to be punched.)
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34. Fig Dental dam stamp. (From Boyd L: Dental instruments: a pocket guide, ed 3, St Louis, 2009, Saunders.)
The dental dam stamp and inkpad are used to imprint the dental dam with predetermined markings for the average adult and pediatric arches.
The template provides flexibility when one or more teeth in the arch are out of alignment.
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35. Dental Dam Forceps
Used in the placement and removal of the dental dam clamp
The beaks of the forceps fit into holes on the jaws of the clamp.
A sliding bar keeps the handles of the forceps in a fixed position.
The handles are squeezed to release the clamp.
The beaks of the forceps are turned toward the arch being isolated.
The handles of the forceps work by way of a spring action.
Why do you think the beaks of the forceps are turned toward the arch being isolated? (This permits the operator to place or remove the clamp without having to rotate the forceps to put them into position.)
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36. Fig. 36-14 Dental dam forceps.
Notice how the hand of the operator is stretched before squeezing the forceps.
After squeezing the spring-action forceps, the operator holds the forceps in position with the sliding bar.
The operator will squeeze the handles again to release the dental dam clamp.
Notice the position of the beaks, which keeps the operator from having to rotate the forceps to place the clamp in position.
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37. Dental Dam Clamps
The primary means of anchoring and stabilizing the dental dam
Parts of the clamp
Bow: rounded portion of the clamp
Jaws: prongs that seat around the tooth create the extension and balance necessary to stabilize the clamp
(Cont’d)
The clamps are made of chrome- or nickel-plated steel and can be sterilized and reused.
The clamps are designed to hold the dental dam securely at both ends, along with a dental dam–stabilizing cord.
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.
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38. Fig. 36-17 Types of dental dam clamps.
Numerous clamps are available for various isolation needs:
Clamps 7 and W7 are universal mandibular molar clamps.
Clamps 8 and W8 are universal maxillary clamps.
Clamps 9 and W9 are designed for anterior teeth.
Clamps 00, W00, and 2 are designed for primary teeth.
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39. Dental Dam Clamps
(Cont’d)
The clamp is designed to fit on the cervical area of the tooth below the height of contour at, or slightly below, the cementoenamel junction.
Winged clamps have extensions to help retain the dental dam.
Posterior clamps are for the maxillary and mandibular posterior teeth.
Anterior clamps retract the gingiva on the facial surface, and improve visibility.
Posterior and anterior clamps are available. The posterior clamp is universal and can be used on the same tooth in the opposite quadrant.
Anterior clamps are designed to retract gingiva on the facial surfaces, improve visibility for class V restorations, and isolate an anterior tooth during endodontic treatment.
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40. Dental Ligature
An important safety measure that makes it possible to retrieve a clamp should it accidentally become dislodged and then inhaled or swallowed by the patient
A dental dam stabilizing cord can be a simple piece of dental floss or dental tape.
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41. Fig. 36-19 Ligature placed on the bow of the clamp for protective purposes.
The slide shows an example of ligation of the dental dam clamp.
Always cut a piece long enough to be grabbed quickly if needed.
Tie the other end of the ligature to the frame of the dental dam to ensure that you can easily find the end.
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42. Dental Dam Application
Steps in preparation and placement
Dental dam equipment and supplies readied
Area of mouth examined for placement
Dam punched
Clamp selected, ligated, and positioned on forceps
Clamp placed
Dam placed
Frame placed
Dam secured and inverted
Applications
Maxillary arch application: Punch the holes 1 inch down from the upper edge of the dam.
Mandibular arch application: Punch the holes 2 inches from the edge.
Curve of the arch: It may be necessary to make adjustments to accommodate an extremely narrow or wide arch.
Use the one-step or two-step method to place the dam. The main difference in the methods is the sequencing in the placement of the clamp and dental dam.
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43. Dental Dam Removal Steps in removal
Remove any ligatures that are stabilizing the dam.
Using crown-and-bridge scissors, cut each hole, creating one slit.
Position the forceps in the clamp.
Remove the dam and frame as a unit.
Evaluate the patient.
Evaluate the dam.
Why is it important to evaluate the dental material after its removal? (Fragments of the dental dam left behind under the gingiva can cause gingival irritation.)
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