Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
Introduction
Dentistry is a surgically orientated part of veterinary science that requires some investment in order to do it at a comfortable level. As many of the procedures are repetitive in nature, it is possible that repetitive strain injuries can occur especially if no attention is given to this.1,2 When done correctly, dentistry can be very rewarding for both professional and patient. I outline the basic principles and equipment a veterinary practice should invest in to start doing the basic procedures at such a comfortable level.
Furniture
Chair
Most of the procedures you will be performing will be in a sitting position. Decide on a chair that is comfortable, adjustable, and keeps the operator's back straight. Such a chair should preferably also be mobile in order for the operator to move around the patient's head.1 Working in a crouched/hunched position over a patient loads the lower back and will lead to discomfort and pain for the operator. This will reduce his/her efficiency and sooner rather than later dentistry will have lost all its potential charm. Being uncomfortable during working also puts the animal at risk of operator injury due to operator fatigue.
Table
A dedicated table for dentistry/dirty procedures is ideal.3 The table should be able to tilt, handle large volumes of fluids and be adjustable. The latter is very important as the operator tries to keep his/her back straight during work and hence working on a large or small dog will alter the heights worked at. Tables with a deep large volume should be guarded against as this volume of cold steel air may aid in causing hypothermia in small patients.
Hand Instrumentation3,4
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Periodontal probe
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Blunt-ended probe with graduations to measure sulcular and pocket depth.
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Dental explorer
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Sharp ended, straight/curved.
Detect irregularities on tooth surface; subgingival calculus deposits; caries; resorptive lesions; patent pulp chamber
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Calculus forceps
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(Extraction forceps)
To remove gross calculus deposits supragingivally
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Supragingival scaler
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Manually removing supragingival calculi
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Subgingival curette
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Remove subgingival deposits and root planing
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Dental mirror
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Visualise a tooth surface, reflect light onto a surface, retractor
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Elevator
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Used to cut the periodontal fibres that are attaching the tooth. The tip can be very thick and cumbersome.
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Luxator
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Another instrument that can be used for the severing of the periodontal ligament before the extraction of a tooth. These instruments are much thinner at their tips which can be advantageous during tooth extraction; however, if they are not used with care and protected during cleaning, the tips can break.
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Periosteal elevator
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Raising a flap for surgical extraction. The head should be of small enough size to accommodate the species worked on. Usually a practice will have at least 2 sizes to accommodate from small cats to large dogs.
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Power Instrumentation
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Sonic
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Fits onto air-driven units and oscillates at less than 20 kHz linear motion, useful for removal of plaque, not calculus.
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Ultrasonic
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Oscillates elliptical/figure of 8, at 20–45 kHz. Water at tip is energised - cavitation
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Magnetostrictive
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Working tip is energised by electromagnetic energy that changes the shape of the laminated ferromagnetic rod stack in the handpiece handle, producing elliptical oscillations. Produces heat.
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Piezoelectric
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Produce changes of the shape of the crystal in the handpiece resulting in oscillating semi-elliptical vibrations at the working tip. Heat production is much less than magnetostrictive.
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Roto-Pro Scaler
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Six-sided non-cutting burr in a fast handpiece.
100.000–200.000 rotations per second leading to 10.000–20.000 impacts per second.
Dislodge calculus but also damages enamel surface. This leads to hypersensitive teeth, and plaque retentive areas. Not a good choice
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Electric Motors
These units are usually used to run a micromotor from. They revolve at up to 30.000 rpm and are perfect for polishing and can be used to section teeth. Remember, with the latter an external water source should be used. This might shorten the life of the motor. These micromotors have the same connecting piece as a low-speed motor of an air-driven unit, hence all contra- and straight handpieces will also fit on them. Speed increasing handpieces should ideally be used when sectioning teeth.
Air-Driven Units3
Handpieces are powered from compressed air, using a local or distant compressor. Water is also integrated with these systems and depending on the type and model you buy, all handpieces can be equipped with water. There are usually 3 stations on such an air-driven unit, one for a high-speed handpiece, one for a low-speed motor, and the third for a 3-way syringe.
High-speed handpiece (Turbine) - 300.000–400.000 revolutions per minute (RPM) are obtained but with little torque.
Low speed motor - These motors rotate at 20.000–30.000 rpm and on its own cannot do anything. Their function is to drive a variety of contra-angle or straight handpieces. These handpieces are mainly used for polishing (4:1 reduction - 5.000–7.000 rpm), but can be used for cavity preparation, endodontics, or even cutting teeth depending on the type of handpiece selected. Straight handpieces are often called surgical handpieces and are commonly used to reduce check teeth in rabbits and other pocket pets.
Care of Dental Equipment
Sharpening of Dental Instruments
Instruments must be sharpened at least after each scaling!
Manual sharpening is superior to sharpening using electrical sharpening devices.
The shape of the instrument must be maintained during sharpening. Thus a knowledge of the shape of each instrument is necessary to avoid faulty sharpening.
The sharp edge must lead across the stone surface.
Instruments should be sharpened along the lateral surface of the cutting edge as opposed to the facial surface as this prolongs the life of the instrument.
A lubricant (oil or water as recommended by manufacturer) reduces surface clogging from sharpening debris. After use, the stone is rubbed well with a cloth to remove this surface debris.
Cylindrical or wedge-shaped stones are used lightly on the facial surfaces to remove the burrs made during sharpening the lateral surface of the cutting edge.
A cheap method of saving the instruments' working life is to protect the tip during washing, sterilisation, and especially transport. Short tubes of used drip line can be used for this.
Advantages of Using Sharp Instruments
Increases efficiency of cleaning
Decreases scaling time and thus reduces anaesthetic time
Prevents unnecessary trauma due to minimal pressure and movement
Less tiring for the person doing the scaling
Care of Ultrasonic Equipment
Components
Electronic generator
Handpiece
Interchangeable inserts
Foot control
Instructions should be read and followed carefully
Flush the water line before the start of each day
Inserts (of handpiece) that are dropped, bent or scratched should be discarded
Inserts and tips should be replaced annually
References
1. Booyens SJ, van Wyk PJ, Postma TC. Musculoskeletal disorders amongst practising South African oral hygienists. SADJ: Journal of the South African Dental Association. 2009;64(9):400–403.
2. Aller MS. Personal safety and ergonomics in the dental operatory. Journal of Veterinary Dentistry. 2005;22(2):124–130.
3. Eubanks DL. Equipping the dental operatory. Journal of Veterinary Dentistry. 2013;30(1):52–54.
4. Reiter AM. Equipment for oral surgery in small animals. The Veterinary Clinics of North America Small Animal Practice. 2013;43(3):587–608.