1. Basic Chairside Instruments and Tray Systems19
Basic Chairside
Instruments and Tray Systems

2. Basic Structural Parts of Dental Hand Instruments
Working end
Shank
Handle
The dental hand instrument can be single or double ended, usually 6 inches long. It is important and will aid the dental assistant by knowing the parts and functions of the dental hand instruments.

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 manufacture’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 the blade
Second number
Length of the blade
Third number
Angle of the blade
Instruments such as chisels, hatchets, and hoes have a series of three numbers

5. Classification of Instruments
Black’s four-number formula
First number
Width of the blade
Second number
Degree of the angle of the cutting edge of the blade to the handle
Instruments such as angle formers and gingival margin trimmers have four numbers.

6. Classification of Instruments
Black’s four-number formula
Third number
Length of the blade
Fourth number
Angle of the blade to the axis of the handle

7. 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.

8. Cutting Instruments Hatchets Hoes Gingival margin trimmers
Angle former
Excavators
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.

9. 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.

10. Noncutting Instruments
Plastic filling instruments
Composite instruments
Amalgam carriers
Amalgam condensers
Carvers
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.

11. Noncutting Instruments
Burnishers
Files
Finishing knives
Miscellaneous
Spatulas
Articulating forceps
Scissors

12. Care and Maintenance
Extend lifespan of instrument due to proper care and maintenance
Properly clean and sterilized
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 presoaked 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.

13. Dental Rotary Instruments
Parts of the bur
Shank
Neck
Head
Straight shank
Latch-type shank
Friction-grip shank
Head
Neck
Shank
Materials that make up the bur is 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, for surgical procedures, and for dental appliance adjustments.
The shank is designed to accommodate the dental handpieces.

14. 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 the student should learn the number ranges.
The diamond burs are used for the cavity preparation and for 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 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.

15. Abrasives
Nonbladed instruments used to finish and polish restorations and appliances
Categorized by the shapes and materials they are made of, such as rubber, stone, and sandpaper
There are abrasives that are used for cutting.
The shapes that categorize abrasives are as follows: discs, points, and wheels.

16. 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.
Mandrels 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.

17. 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.

18. Types and Functions of Abrasives
Rubber wheels
Used for finishing and polishing
Rubber points
Used for polishing
Adaptable for defining anatomy in restoration
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.

19. 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
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.

20. 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.

21. Dental Handpieces High-speed handpiece Low-speed handpiece
Electric handpiece
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 the laboratory. Its uses in the dental office is to polish teeth and restorations, remove soft carious material, and define cavity margins and walls.
Electric handpiece are an alternative to the air driven handpiece. They are more versatile and are used more commonly today.

22. Maintenance and Sterilization of Dental Handpieces
Follow manufacturer’s directions carefully
Sterilization
General guidelines for maintenance and sterilization of a dental handpiece is as follows:
While handpiece is still attached to the tubing and a bur, flush for twenty to thirty seconds.
Remove debris by scrubbing handpiece.
Lubricate using manufacturer’s suggested lubrication.
Sterilize the handpiece.
Lubricate if instructed.

23. 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.

24. Tray Systems Preset tray system Other systems Most commonly used
Instruments and auxiliary items
Placed on a tray in the order of their use during the 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.

25. 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.