1. Basic Chairside Instruments and Tray Systems
Chapter 18

2. Basic Structural Parts of Dental Hand Instruments
Working end
Shank
Handle
The dental hand instrument can be single- or double-ended and is usually 6 inches long. It is important and will aid the dental assistant by knowing the parts and functions of the dental hand instruments.
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3. Basic Classification of Dental Instruments
Number of working ends
Functions
Manufacturer’s number
Black’s formula
By knowing the classifications, it is easier to remember each instrument’s name and function.
The two categories of working ends are single-ended and double-ended.
If an instrument is classified by function, there is cutting and non-cutting. Also, there are instruments used for a specialty.
On the handle of an instrument is the manufacturer’s number. Some instruments will have the name of the individual who designed the instrument.
Black’s formula consists of the exact size and angulation of an instrument.

4. Classification of Instruments
Black’s three-number formula
First number
Width of blade
Second number
Length of blade
Third number
Angle of blade
Instruments, such as chisels, hatchets, and hoes, have a series of three numbers.
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5. Classification of Instruments
Black’s four-number formula
First number
Width of blade
Second number
Degree of angle of cutting edge of blade to handle
Instruments, such as angle formers and gingival margin trimmers, have four numbers.
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6. Classification of Instruments
Black’s four-number formula
Third number
Length of blade
Fourth number
Angle of blade to axis of handle
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7. Dental Check
What is the end of the working end called if it is blunt and serrated?
Nib

8. Cutting Instruments Chisels Straight Wedelstaedt Bi-angle
Hand cutting instruments are used in cavity preparation. Chisels are unique hand cutting instruments because they come in three different shanks to reach different areas of the mouth.
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9. Cutting Instruments Hatchets Beveled on one side Blade on one side
Refines cavity walls
Obtain retention in cavity prep
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These instruments are used to refine and define different areas of the cavity prep. It is important for the dental assistant to be able to identify and know the use of each instrument. By doing so, the dental assistant will be able to assist the doctor in a more efficient and accurate manner.

10. Cutting Instruments Hoes Smoothes and shapes floor of cavity prep
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11. Cutting Instruments Gingival margin trimmers Curved blade
Angled cutting edge
Bevel gingival margin wall of cavity prep
Distal
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Mesial
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12. Cutting Instruments Angle formers Define point angles
Sharpen line angles
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13. Cutting Instruments Excavators Blade or spoon
Removal of carious materials
Removal of excess cement
Tucking of rubber dam
Packing of retraction cord
Blade
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Spoon
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14. Dental Check
Name the cutting instrument that is used to plane and shape enamel and dentin walls.
Chisel

15. Noncutting Instruments
Basic examination instruments
Mouth mirrors
Explorers
Cotton pliers
Periodontal probes
Common to all tray setups, these instruments are used to begin all procedures.
There are three types of mirrors: Plane or regular surface mirrors, front surface mirrors, and concave surface mirrors. The most common size used is a 4 or 5.
The explorers come in a variety of angles and different ends in order to access various areas of the mouth. It is used to detect irregularities. Common shapes include the pig tail, the shepherd’s hook, and the right angle.
Cotton pliers are used to remove, transfer, and retrieve materials from the oral cavity and/or drawers and cupboards. Their handles are either locking or non-locking, and the tips may be straight or angled.
The periodontal probes measure the depth of the gingival sulcus. An instrument called the expro is a combination of a periodontal probe and an explorer.
Mirror and explorer Courtesy of Integra Life Sciences Corporation (through Integra Miltex)

16. Noncutting Instruments
Plastic filling instruments
Placing and condensing restorative materials
Composite instrument
Placing, condensing, carving, contouring, and burnishing
These instruments are used after the cavity has been prepped. It is important for the dental assistant to learn these instruments and the sequence in which they are used. The instruments are used for placing bases and liners, placing amalgam and composites, and contouring and smoothing final restoration.
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17. Noncutting Instruments
Composite instruments
Amalgam carriers
Amalgam condensers
Carvers

18. Noncutting Instruments
Amalgam carrier
Carry and dispense amalgam
Amalgam condenser
Pack amalgam into cavity prep
Courtesy of Integra Life Sciences Corporation (through Integra Miltex)
Courtesy of Hu-Friedy Mfg., Co., Inc.

19. Noncutting Instruments
Carver
Remove excess restorative material
Carve wax inlays and onlays
Courtesy of Hu-Friedy Mfg., Co. Inc.

20. Noncutting Instruments
Burnishers
Smooth restorations
Shape matrix bands
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21. Noncutting Instruments
Files
Trim filling material
Finishing knife
Trim excess material
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Courtesy of Hu-Friedy Mfg., Co. Inc.

22. Noncutting Instruments
Miscellaneous
Spatulas
Articulating forceps
Scissors
Courtesy of Integra Life Sciences Corporation (through Integra Miltex)

23. Care and Maintenance
Extend lifespan of instrument due to proper care and maintenance
Properly clean and sterilize
Examine all instruments thoroughly
All instruments should be properly cleaned and disinfected as soon as possible after use. If they are not able to be cleaned right away, they should be pre-soaked in a solution to prevent the debris from drying on the instruments. Instruments should be cleaned in an ultrasonic bath or other similar solution. Hinged instruments should be cleaned in the open position and should be lubricated as appropriate. After cleaning for the appropriate amount of time, the instruments should be rinsed and dried. Once dried, they should be sterilized and stored. All instruments should be carefully inspected before use for properly functioning parts, broken parts, and sharpness.

24. Dental Check
Which type of burnisher is popular for smoothing amalgam or composite restorations?
Acorn

25. Dental Rotary Instruments
Parts of bur
Shank
Neck
Head
Straight shank
Latch-type shank
Friction-grip shank
Head
Neck
Shank
Materials that make up the bur are either steel or tungsten carbide. You will find burs not only used chairside, but also in dental laboratories.
The use of burs is as follows: cavity preparation, finishing and polishing restorations, surgical procedures, and dental appliance adjustments. The shank is designed to accommodate the dental handpieces.
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26. Types of Burs Cutting Diamond Finishing Surgical Laboratory
Fissurectomy
The burs are divided into categories according to their use. The cutting burs are separated into different shapes and sizes. These burs are numbered, and students should learn the number ranges. The diamond burs are used for the cavity preparation and finishing the restoration. The finishing burs come in different shapes and are used to smooth the restoration. The surgical and laboratory burs may look similar, but the surgical burs are used in the mouth, and the laboratory burs are used on fixed and removable prostheses. Fissurotomy burs are extremely small and are used to explore the occlusal surface to treat and diagnosis while maintaining tooth structure.
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27. Abrasives
Nonbladed instruments used to finish and polish restorations and appliances
Categorized by shape and materials from which they are made
E.g., rubber, stone, sandpaper
There are abrasives that are used for cutting. The shapes that categorize abrasives are as follows: discs, points, and wheels.

28. Types and Functions of Abrasives
Mandrels
Rods of various lengths used in low-speed handpieces
Discs
Used to polish, smooth, and adjust restorative materials and dental appliances
Mandrels are used with different abrasives, which are either mounted to the mandrel or unmounted. They come in three different shanks: latch, friction grip, or straight.
The types of discs are as follows: sandpaper discs, diamond discs, and carborundum (also known as Jo-Dandy discs and separating discs). They are thin and brittle and break easily.

29. Types and Functions of Abrasives
Stones
Used for cutting, polishing, and finishing amalgam, gold, composite, and porcelain restorations
Stones are used in the laboratory and are available in many sizes, shapes, and grits.

30. Types and Functions of Abrasives
Rubber wheels
Used for finishing and polishing
Rubber points
Used for polishing
Adaptable for defining anatomy in restoration
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After using an instrument in the oral cavity, it is either sterilized or properly disposed. The bur block comes in a variety of designs and sometimes can be sterilized with the burs they hold.
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31. Dental Check
What type of bur is used to open the cavity and remove the carious tooth structure?
Round

32. Dental Handpieces Used for the following: Remove dental decay
Prepare tooth for restoration
Polish
Polish and finish dental restorations
Cut, finish, and polish dental appliances
Trim models and trays
The electric handpieces are becoming more popular than the air-driven handpieces. The appeal of the electric handpiece is that it is quiet, vibration-free, efficient, and able to be sterilized.

33. Parts of the Dental Handpiece
Working end
Head
Shank
Connection end
The working end is where the burs, discs, stones, and other rotary instruments and attachments are held. Forward and reverse controls may be located on the connection end.

34. Dental Handpieces High-speed Low-speed Electric
High–speed handpieces can produce frictional heat, which can cause pulpal damage to the tooth. So it is important to use a coolant, such as air, water, or and air-water spray to reduce the frictional heat.
Low-speed handpieces are used in both the dental office and laboratory. Its uses in the dental office are to polish teeth and restorations, remove soft carious material, and define cavity margins and walls.
Electric handpieces are an alternative to the air-driven handpiece. They are more versatile and used more commonly today, allowing for smoother cuts and refined margins with higher torque and precision.
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35. Maintenance and Sterilization of Dental Handpieces
Follow manufacturer’s directions carefully
Sterilization
General guidelines for maintenance and sterilization of a dental handpiece are as follows:
- While handpiece is still attached to the tubing and a bur, flush for 20 to 30 seconds.
- Remove debris by scrubbing the handpiece.
- Lubricate using the manufacturer’s suggested lubrication.
- Sterilize the handpiece.
- Lubricate if instructed.

36. Air Abrasion Unit and Microetcher
Reduces use of anesthetics and drilling with dental handpieces
Microetcher
Smaller version of air abrasion unit used for intraoral sandblasting and dentin bonding
Both units require air pressure and an abrasive material. Abrasives used in the microetcher should be kept in a tightly sealed container to keep them dry and clean. It is important to consider safety for all involved while using a microetcher.

37. Tray Systems Preset tray system Other systems Most commonly used
Instruments and auxiliary items
Placed on tray in order of use during procedure
Other systems
An example of a preset tray system is the cassette system. This system allows instruments to be transported to treatment rooms, through the sterilization process, and into storage. It keeps the instruments for each procedure together at all times.

38. Color Coding Systems Color coding may be set up to indicate:
Procedures
Treatment room instruments storage
Additional sets of instruments
Individual operators
Sequence of use
Any combination of the above
Color coding makes it easy to identify instruments and trays. It is important that the material used for color coding is autoclavable and durable. Types of materials used for color coding include plastic rings and colored coding tape.

39. Color Coding Systems
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