As in every medical discipline, odontostomatology mandatorily requires, besides suitable scientific preparation, technical knowledge about the instruments needed to perform dental procedures. The equipment that the professional decides to purchase has to be proportionate to the volume of work expected and to the type of operations she/he expects to perform most often. Some equipment and some instruments are often unnecessary in daily practice, while others are essential, hence it is not easy to orient oneself among the many products proposed by the industry; in addition, there is a continuous offer of materials derived from human dentistry, which are totally useless, if not actually harmful.
Note: The equipment and materials reproduced in photos or videos are the author’s property; any references to brands and/or manufacturers are purely accidental and are not for advertising purposes.
Periodontal disease, which affects over eighty percent of dogs and is also widespread in the feline population, is almost always associated with tartar (mineralised plaque) deposits, which can only be removed with mechanical means. Not all domestic carnivores are affected equally; indeed, as in the human species, an individual predisposition to developing this disease has been proved; in addition, a predisposition linked to the breed and to the size of the animal, as well as to the shape of the mouth, has been verified. Tartar and plaque removal is most likely the procedure which is performed most frequently in veterinary odontostomatology; it can be carried out correctly using manual tools, power scalers and ultrasonic scalers.
MANUAL TOOLS
Curettes
Curettes (Fig. 1) are used to remove subgingival tartar, to smooth root surfaces and for the curettage of gingival pocket epithelium in order to remove granulation tissue, while scalers, which are much sturdier, are used to remove supragingival tartar. Curettes are used for various purposes based on the shape of the blade (Fig. 2): removal of supragingival and subgingival tartar, smoothing of root surfaces, curettage of pocket epithelium to remove granulation tissue, etc. The use of these instruments requires a high degree of specialization; indeed, the manual skills necessary for the correct execution in order to obtain the desired result require considerable experience; in addition, the procedures that can be carried out with these instruments are slow and thus imply long anaesthesias. In order to be efficient, these instruments must always be kept sharp using Arkansas stones and specific mineral oils (Fig. 3); sharpening techniques for the curette also require specific manual skills, which can only be acquired by attending specific courses. It is also worth recalling that ultrasonic scalers that can be fitted with “subgingival” inserts may replace many of the operations that can be performed with curettes.
Scalers
These instruments have a triangular working section, with two sturdy blades available (Fig. 4) for the removal of supragingival tartar and plaque. The size of the blades make it impossible to insert scalers inside the gingival pocket; for this reason scalers cannot be used to remove subgingival tartar, but only supragingival tartar (Fig. 5). As for curettes, these instruments can also be conveniently replaced with ultrasonic scalers.
SCALERS WITH ABRASIVE POWDER
Connecting an air-powder system, which mixes micronised sodium bicarbonate powder with air and water, to the outlet of a hose of the dental unit, a spray is generated that is capable of removing plaque and tartar from the tooth surface. Air-powder scalers (Figs. 6 and 6b) make it possible to reach every recess and, if used with an angle of incidence of 30 – 60°, do not damage the enamel. It should be kept in mind that the spray, which comes out with considerable pressure, can damage soft tissues and usually causes a slight gingival bleeding.
ULTRASONIC SCALERS
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Ultrasounds Effects of ultrasounds
Cavitation: with formation of microbubbles. |
Ultrasonic scaling, indicated for removing supragingival and subgingival tartar, involves the use of instruments that can have various principles of operation: piezoelectric, magnetostrictive, sonic and rotosonic; regardless of the system, it is worth recalling that during the scaling operation the work environment is polluted by a bacterial aerosol coming from the microbial flora of the oral cavity and that the operators who perform the ultrasonic scaling procedure (veterinarians, paramedical personnel, etc.) are also exposed to this contamination and should thus protect themselves with closed gowns, masks, goggles, etc. The room where the scalingprocedure is performed should be properly disinfected and the clothing worn during the procedure should be changed before performing other surgical procedures. As previously mentioned, there are various types of ultrasonic scalers: piezoelectric, magnetostrictive, sonic and rotosonic; although all four types of scalers have the same function (ultrasonic impact and cavitation effect), it is useful to know that the piezoelectric scaler removes tartar more quickly than the other three and that the rotosonic type causes more damage to the enamel. In all cases, when the enamel covering the crown comes into contact with the scaler it sustains damage that must then be corrected through polishing with prophylaxis cups (also known as prophy cups).
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Cavitation |
Piezoelectric scaler
Ultrasounds are produced by taking advantage of the piezoelectric effect, which is produced by the action of an electrode on materials like quartz and ceramic. Indeed, if we apply an electric field to quartz crystals, for example, a crystal compression wave is generated; by reversing its direction, we will obtain an expansion wave, and a series of high frequency mechanical vibrations will be produced that can be used in medical therapy (Figs. 7 and 8).
Magnetostrictive scaler
Magnetostrictive scalers (Figs. 9 and 10) produce ultrasounds by activating a lamellar pack the vibration of which is transferred to the scaler tip. Generally speaking, these devices automatically find the operational frequency, which makes it possible to adapt the scaler to the optimal state of resonance between handpiece, tip and surface to be treated.
Sonic scaler
This type of scaler is generally supplied as a handpiece to be inserted on the hose of dental units; it comes with a 2-way Borden connector, 3-way Borden connector, 4-way Midwest, electrified Midwest, Midwest USA and quick connector (Video 1). The generation of ultrasounds entails an increase in the temperature of the treated surfaces; for this reason, it is essential to cool the dental components with a continuous spray of water. The cooling water for the treated surfaces may come directly from the urban water supply system, from a demineralisation system or be contained in the scaler's tank (Fig. 8). When choosing an ultrasonic scaler one must take into account the hardness of the water supplied from the local aqueduct: in geographical areas where the water is particularly hard, scalers fitted with their own tank are preferable over those without a tank (Fig. 7), as the limescale contained in the water supply system may block the very thin ducts of the device, making it unusable. Another advantage of ultrasonic scalers fitted with their own tank is the possibility of adding small amounts of disinfectants, such as chlorhexidine, to the cooling water.
INSERTS
Each scaler is provided with specific inserts (original or compatible) that are fitted to the handpiece with different locking modalities: screwed, pressure inserted or tightened with a dedicated torque wrench (Video 2); before purchasing any insert it is recommended to make sure that is it compatible with the available instrument.
Inserts are intended for different functions, depending on their shape. In general, inserts can be divided into three functional categories:
- Treatment of tooth surface (Fig. 11): these are the inserts which are most often used in veterinary medicine and with any type of scaler, as all scalers support this category of inserts and because supragingival scaling is the dental procedure which is most often performed. The working surface of these inserts can be flat, spatula-shaped, sickle-shaped, etc.; it is important to select the shape most suitable for the surface to be treated.
- Treatment of roots: for many years the practice of scaling subgingival plaque and tartar was performed using curettes; scalers that can fit inserts for the treatment of roots have been available for several years; these inserts are long, thin and are provided with an irrigation system that extends to the area to be treated.
- Endodontic treatments (Fig. 12): ultrasound scalers can also be used for the treatment of root canals; special inserts are necessary, fitted with files which, once tightened (Video 3), allow the treatment of the inside of the tooth.
The mode of operation and, consequently, the power of the scaler should be adjusted in accordance with the type of insert (Video 4).
The inserts should be kept in suitable insert holders (Fig. 13) and should be autoclaved, together with the handpiece (Fig. 14) and with the torque wrench, in order to prevent the transmission of infections from one patient to the other (Video 5); should there not be enough time to sterilise in an autoclave, a chemical disinfection is possible, for example using chlorhexidine; the handpiece should be protected with specific cover sleeves (Video 6).
Independently of the type of scaler used, after ultrasonic scaling, polishing [25] of the surface of the treated teeth is necessary, using prophy cups and the appropriate polishing paste or special paste-less polishers.