Chapter 19 Chairside Instruments and Tray systems.

Structural Parts of Dental Hand Instruments Working End The end of the instrument that actually performs the function. Comes in three generalized categories. Point Blade Nib

Descriptions of the working end! Point: sharp tip used to: explore and detect. Example: explorer

Description of working end cont. Blade: flat or curved, rounded edge or a cutting edge. beveled or bi-beveled, Example: Gregg 4/5 (round edge), Hollenback carver, (beveled edge).

Description of working end cont. Nib: a blunt or flat end. serrated or smooth. Example: Amalgam condenser, Endodontic plugger.

Classification of Dental Instruments Instruments are classified by: Number of working ends. Function. Manufactures name. Black’s number formula. G.V. Black

Number of working ends Single-ended: Double-ended: one working end generally a longer handle. single function multi-function Double-ended: ends are same, opposite directions left and right different functions different sizes paired mesial or distal

Instruments classified by function CUTTING: used to design (shape or form) the cavity prep, define and refine walls / floor of the prep. Cuts enamel and dentin.

The six cutting hand instruments 1. Chisels: shapes the walls, pushing motion. 2. Hatchets: refine walls / retention, paired left and right. 3. Hoes: smooth and shape the floor pulling motion. 4. Angle formers: defines point angles = corners of the prep. downward pushing motion.

Chisel Hatchet Hoe Angle former

Cutting instruments cont. 5. Gingival margin trimmer (GMT) double ended instrument comes paired mesial and distal. Are used to bevel (slant or angle) the gingival margin of the cavity prep. cuts enamel. It does not trim/cut the gums.

GMT distal GMTmesial

Cutting instruments cont. 6. Excavator, AKA Spoon excavator scoop and remove caries and debris from the prep/tooth. Double ended Used when there is a risk of perforating into the pulp chamber with the handpiece and bur.

Spoon excavators

Carving instruments T-3 carver: Hollenback carver: carves amalgam occlusal and proximal surfaces Hollenback carver: carves amalgam proximal surfaces. Cleoid-Discoid carver: aka (C-D) carves amalgam occlusal. All can be used to carve anatomy (pits and fissures) into the occlusal surface.

Cleoid- discoid Hollenback T-3

Basic set-up Standard basic set-up. Mouth mirror Explorer Cotton pliers AKA cotton forceps or pick-ups.

Aspirating Syringe and needles. Delivers anesthetic! Used to check needle position. Not in a vein. Needles Different ga. Size of opening 25, 27, 30 (common) Different lengths X-long / Long Short / X-short

Dental Rotary Instruments Burs, aka rotary instruments! discs, stones, rubber polishers, mandrels, lab burs. Used for cavity preparation, finishing and polishing restorations, surgical procedures adjusting appliances.

Parts of the bur! Shank: Straight shank: Latch-type shank: the part of the bur you place in the chuck of the handpiece. Straight shank: larger diameter shanks associated with lab burs. Latch-type shank: has a notch contra-angle attachment slow-speed handpiece Friction-grip shank: smooth on the end high-speed handpiece

Parts of the bur cont. Head: Neck: is the working end of the bur. It performs the function. different shapes different sizes different # of blades or coarseness Neck: is the tapered part of the bur that connects the shank to the head of the bur.

Carbide Burs Round: FG or latch, opens the tooth and removes caries. Sized 1/4 - 10

Carbide Burs Inverted cone: FG or latch, removes caries and place retention grooves / undercuts. Sized 331/2 - 37 or 37L (long)

Straight. Cross-cut. Tapered Cross-cut fissure. straight fissure Straight Cross-cut Tapered Cross-cut fissure straight fissure fissure tapered fissure

Carbide Burs cont. Diamond burs: End cutting: Wheel: Pear: rapid reduction of tooth structure (coarse) polishing and finishing (fine) occlusal adjustments. Identified by grit: (fine, med., coarse) Variety of shapes and sizes. End cutting: form the shoulders of crown preps. Wheel: used to form retention in the prep. Pear: used to open and extend the prep. Sized 329-331(L)

Diamond burs.

Additional Burs Finishing burs: Surgical burs: smooth, trim, and finish restorative material. increased # of blades (carbide) or finer grit (diamond) different shapes and sizes, gold colored shank (carbide) Surgical burs: FG or latch grip, reduce, remove, or reshape the bone section (cut) a tooth into pieces. Many shapes and sizes shaft of the bur is longer

Additional burs cont.

Additional rotary instruments Stones: used for cutting, polishing and finishing restorations and appliances. Many different shapes and sizes. Common stones white and green stones. Rubber points or cups: aka greenies, and brownies. FG or latch. polish metals and define anatomy in restorations. polishing amalgam and gold

Additional rotary instruments

Additional rotary instruments Lab bur: AKA acrylic bur or a vulcanite bur. Used to adjust appliances, extraorally. used in a lathe in the dental lab. Many different shapes and sizes. Mandrel: designed to hold polishing disks. used to smooth, polish and adjust composite. different grits, discs are made of: metal, plastic, paper.

Additional rotary instruments

Bur Blocks Bur blocks hold, separate, and organize burs. set up by bur, doctor, or procedure. magnetic different shapes and sizes, autoclaveable.

High Speed Handpieces Working end: Shank: Connection end: aka head where the bur is placed Shank: aka the handle. the part of the handpiece you hold onto. Connection end: the end that attaches to the power source or line.

Slow-speed handpiece AKA low-speed, or straight handpiece. Rotates about 30,000 rpm. Used with a contra-angle or pro/right angle attachment. No water, but can and does produce frictional heat.

Instrument tray systems Pre-set trays: very common, saves time. Instruments should be set according to the order they will be used. This may vary from doctor to doctor. Color-coding: may be used to identify: Which procedure they are for. Which operatory they belong in. Which doctor they belong to.

Instrument tray systems

Closing Knowing and understanding dental instruments and their functions are very important parts of your job. This is a foundation for you to build you instrument knowledge. Any questions?