Ultrasonics

Since the late 1950s, the use of ultrasonic technology has become a staple in endodontic practices around the world for hygiene and periodontal procedures. More recently, endodontists have introduced us to the clinical advantages of their use in root canal therapy, and we are just beginning to see their effectiveness for endo-restorative and microrestorative work.

Distinguishing Features and Improved Technology

The first piezoelectric ultrasonic was introduced to the market by Satelec in the late 1970s. Since that time, there has been an evolution in the technology, operation, ergonomics, and the design of the machines. The most important feature of any ultrasonic unit is how it maneuvers the tip and adjusts to many different tip designs (each with a unique intended function). A good ultrasonic machine also must adapt to several unpredictable clinical conditions and tooth anatomy.

WATER, AIR, VISION, AND LIGHT

Many design elements are incorporated into a number of high-quality piezoelectric models. Optional fiber-optic or LED handpiece certainly enhance visibility, but may be an unnecessary expense if the operator is using a high-powered LED headlight or a microscope. In any event, intense light, good magnification through loupes or a microscope, and reliable ultrasonic technology are all a must if you are doing molar endodontics. Water has always been inherent to ultrasonic use; being necessary for magnetorestrictive units to cool the handpiece, the tooth surface, and the tip. Piezoelectric units still require the use of water in periodontal and hygiene procedures, but for most endodontic applications water is discretionary.

THE USES

Finding and Breaking Into Hidden Canals and Access Enhancement

For both general practitioners and endodontists, the ultrasonic is a valuable tool to treat calcified and difficult to find canals, as long as it is complemented by the proper tip, and sufficient magnification and light. It is less aggressive than a high-speed handpiece, and with high magnification the operator can always see where the tip is and where it is heading. By contrast, the high-speed handpiece affords little if any visibility in access procedures, so the dentist must constantly stop, look, and start again to avoid procedural mishaps.

Obstruction Removal

In the natural course of the life of a dental practice, specialty or general, cases will present that will require retreatment of a previously restored, endodontically treated tooth. This will often entail disassembly of the restoration, perhaps including removal of a metal post, a silver point, gutta-percha, obturation carriers, etc. There is also the possibility of instrument separation during root canal therapy, which usually requires immediate intervention. The piezoelectric ultrasonic is also an invaluable tool for these procedures. In such situations, good case selection is very critical; frequently the endodontist has the proficiency to handle these procedures, having been well educated on the justification and protocols for retreatment, possessing valuable experience in retreating many cases over many years, and having all the instruments and tools essential to deal with the most difficult, unusual, and sometimes unforeseen conditions under which most retreatment is done. good case selection are also vitally important.

Other Miscellaneous Uses in Endodontics

Ultrasonics are also presently used in removing gutta-percha, condensing gutta-percha, vibrating perforation repair material, such as mineral trioxide aggregate, into location, and root end surgical preparation. Currently, there are an increasing number of restorative procedures, which are ideal for ultrasonic applications such as margin finishing, interproximal, and small lingual restorations, and more advances in oral surgical applications are in development.