Dental Laboratory InstrumentsMr. CaputoUnit #1 Lesson #9

Today’s Class• Driving Question: How are dental laboratory instruments used

in a dental office?

• Learning Intentions: We will be able to identify how to care for dental laboratory supplies and equipment.

• Anchor: Explain why infection control should be practiced by all dental workers.

Equipment Requiring Heat Sources

• Alcohol torches, butane torches, and Bunsen burners are used for smoothing wax surfaces, setting teeth, and heating wax-carving instruments

• Important to periodically trim all irregular burned areas of alcohol torch wick and to check nozzle tip of alcohol and butane torches

• Bunsen burner requires balanced air and gas mixture to produce clean blue flame

Vacuum Former

• Used for rapid fabrication of custom trays, mouth guards, splints for temporary crowns, night guards for bruxism, and bleaching trays

• Softens sheet of plastic with heat and then pulls it down onto the cast with suction

• Trimmed model is placed on platform and heat is turned on• Heated plastic sheet hangs down over model approximately 1

to1 ½ inches, DA grabs handles of frame and pulls it down onto model, and then immediately turns on suction to draw hot plastic onto model

Vacuum Former

Courtesy Keystone Industries

Articulators

• Designed to reproduce movements of mandibular arch in proper centric occlusion to maxillary arch

• Dental casts made from patient’s impressions are mounted onto articulator with lab plaster

• Various types are available• Facebow may be part of articulator

Facebows

• Used to record relationship of maxillary arch to horizontal axis rotation of mandible

• Rests on face and occlusal relationship is recorded by inserting wax, vinylpolysiloxane, or another material into oral cavity

• Requires three points of reference • Earpiece facebow may be required

Articulator

Dental Lathe

• Rotary machine used during grinding, finishing, and polishing procedures

• Has extensions at both ends• Adapter or chuck is used to secure a wide variety of rotary

instruments onto either extension• Instruments that can be attached to the lathe include acrylic burs,

arbor bands, dental stones, and ragwheels

Dental Lathe

• Flour of pumice may be used in conjunction with dental lathe• All brushes, ragwheels, and other laboratory tools should be used

only for one patient and sterilized between patients to prevent cross-contamination

• Pumice solution used at polishing lathe should be dispensed following unit dose concept

Mixing Bowls

• Made of flexible rubber or plastic material• Used to mix alginate impression and gypsum

materials• Small, medium, large, and extra-large sizes • Spatula is used to blend powdered alginate or

gypsum and water together in the bowl• Should be disinfected by spraying with disinfectant

and wiped dry for storage• Disposable bowl liners and wooden spatulas may

also be used

Vibrators

• Used to move dental plaster or stone gypsum products when pouring a cast model

• Impression is placed on flat-top working surface of vibrator as gypsum material is poured into it

• Vibrator increases density of mix by eliminating air bubbles• Control knob is used to adjust intensity of vibration• Rubber platform should be kept covered with plastic cover

and damp paper towels

Vibrator

Model Trimmer• Used to trim and contour gypsum cast models• Electrically operated machine that has round

abrasive wheel, short working table, and water-dispensing mechanism

• Wheel rotates while water flows onto it, keeping it clean

• When finished, allow the water to run for one full minute to flush out particles from trimmer drain to prevent clogging of gypsum material in plumbing lines

• When operating, fingers should be kept away from wheel and safety glasses or goggles should be worn

Model Trimmer

Common Instruments Used in the Dental Laboratory

• Lab spatulas with narrow or broad flexible blades• Wax spatulas made of metal• Lab knives

Homework #4• Explain how you would train a dental worker in infection

control.