1. Field of the Invention
This invention relates to airbrasive devices, and more particularly to devices for containing abrasive materials expelled by a gas-abrasive apparatus. The invention is particularly useful for dental applications.
2. Background of the Invention
The use of sandblasting devices to contact various surfaces has been known for some time. These devices are also known in the art as airbrasive or air-abrasive devices. Such devices vary in size and design depending on the particularly utility desired.
One area where use of these devices has proved advantageous is in the etching or abrading of small surfaces. Devices designed for this use are typically hand held and capable of delivering fine streams of air-abrasive material through narrow nozzles.
A number of decades ago, the use of air-abrasive devices gained favor in the dental art The methods developed were termed "airbrasive techniques" and were designed to supplement the use of traditional dental drills to prepare a tooth for cavity repair, prophylaxis or other methods that required that a portion of the tooth be removed or that required the roughing of a tooth surface. The advantage of using air-abrasive techniques is that the dental patient experiences less trauma to the oral cavity due to the absence of perceptible pressure, vibration, noises created by the contact of a drill to tooth enamel, and heat created by frictional forces. This has resulted in reduced pain, apprehension, and fear by patients.
One disadvantage of the use of air-abrasive dental apparatus is that abrasive materials are dispersed into the oral cavity during use in a relatively uncontrolled fashion, can be inhaled by the patient, and are difficult to remove after a procedure is complete. Another disadvantage is that such particles can be dispersed into the air and create a hygiene problem. Abrasive particles can carry pathogens and blood particles from the mouth and permit those pathogens and blood particles to contact otherwise uncontaminated surfaces.
Somewhat similar disadvantages exist with use of air-abrasive devices in other applications. Often it is desirable to prevent abrasive materials from contacting surfaces proximate to the target surface, from accumulating abrasive material on the target surface area, or from permitting fine abrasive particles from becoming airborne.
Several devices have been developed to affect the dispersion of abrasive particles within the oral cavity. Coston, U.S. Pat. No. 5,197,876 discloses a splatter guard for air polishing dental devices. The guard comprises a bell-shaped flexible cone that is attached to the end of an air-abrasive device and guides abrasive particles towards the surface being treated. Ho, U.S. Pat. No. 5,356,292 discloses a dental sandblasting confiner in the form of a flexible transparent cup. The nozzle of a sandblasting device can be inserted in large opening of the cup which forms a mold around the nozzle. The Ho device contains additional openings for access to a tooth surface and for discharging output. Lokken, U.S. Pat. No. 4,611,992 discloses an anti-splash device that can be attached to a dental tool. The device comprises an inverted U-shaped member with legs for attaching the device to the dental tool. Wright, U.S. Pat. No. 4,850,868 discloses a spray shield comprising a modified tube that can be attached to the end of a dental handpiece. The device is used to direct material dispensed form the handpiece in a controlled fashion so as to minimize the amount of airborne particles.
While the above cited inventions address one or more of the described disadvantages of air-abrasive systems, they are subject to several detrimental limitations. Although minimizing the amount of abrasive material released, by guiding it downward for instance, has certain benefits, it is more preferable to contain a substantial portion of released abrasive material and permit facile removal. Many of the devices in the prior art guide, but do not completely contain abrasive material nor permit easy removal thereof. Other devices that do permit removal of abrasive material are obtrusive and interfere with visualization of the surface to be abraded, making it difficult to perform precise dental procedures. Furthermore, those devices that do permit removal of abrasive material typically rely on a vacuum source to remove that material. Such a vacuum source adds additional expense and can also be intrusive.
Thus, there is a need for a device that can contain a substantial portion of the abrasive material expelled from an air-abrasive device while not obstructing visualization of the surface to be abraded and permitting removal of the abrasive material without the aid of a vacuum source.