Dentistry – Apparatus – Having intra-oral dispensing means
Reexamination Certificate
2001-07-03
2002-07-09
O'Connor, Cary E. (Department: 3732)
Dentistry
Apparatus
Having intra-oral dispensing means
Reexamination Certificate
active
06416322
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
The disclosed device and method for use are in the field of dental tools.
2. Description of Prior Art
Restorative dental work includes a computer-aided method of making a replica tooth from a ceramic block through the use of a computer controlled milling machine. The replica tooth is made based on the tooth to be restored. This tooth is in the patient's mouth. The tooth is prepared by removal of silver fillings and any decayed material. The next step is to capture the shape of the tooth. In order to capture the digital image of the tooth by an imaging device, the tooth is made to contrast with the rest of the patient's mouth by coating the surfaces of the tooth with a suitable powder. This step is known as “powdering” the tooth. The imaging device is used to collect an image of the powdered tooth.
One such method uses a powder comprised of titanium dioxide and talc. The imaging system is a handheld infrared camera. Such a system is manufactured by Siemens Dental Products Division and distributed in the United States by Patterson Dental Supply, Inc. of St. Paul, Minn. under the name CEREC® 3.
Although the CEREC® 1, CEREC® 2 and now CEREC® 3 systems have been used for over a decade, the powdering devices are not well liked by the dentists that powder teeth. The powdering device is important because powdering is the first step towards successful completion of this restorative dental work. Problems with the application of the powder interfere with the attainment of suitable results in the imaging and digitizing steps. More specifically, the CEREC® 3 computer converts the light and dark areas of the image of the tooth into values representative of the height and depth of the surface of the tooth. This imaging process requires the application of a uniform coat of powder so that the entire target surface is covered. Too much powder is a problem as is too thin a coat. Thus, it is important to have a process that applies a uniform coat of powder to the target area.
One prior art device for this critical “powdering” step involved a pair of containers. One container held pressurized butane gas. The second container held the reflective powder. The device operated by releasing butane from the first container into the second container. The butane then carried reflective powder out of the second container and through a flexible tube towards the tooth to be coated. Such an applicator was distributed by Vita Zahnfabrik H. Rauter Graph and Co. KG of Bad Sackingen, Germany. Alternative suppliers of the butane propellant devices are Ivoclar™ (sold as ProCad powder) and Vita™ brand powder. Typically, these powdering techniques call for using a brush to apply imaging liquid to all the surfaces visible in the imaging step. The surfaces are blown dry after the imaging liquid is applied. Next the powder is sprayed on in a steady stream from a nozzle held about one or two centimeters from the tooth surface.
An alternative device is described in U.S. Pat. Nos. 5,944,521 and 6,099,306 for a Tooth Powdering Applicator issued to David Lawler. The Lawler device replaces the attached container of pressurized butane with a connection to a pressurized fluid. The outlet tube is rigid and curved. The Lawler device was designed to allow a dentist to use a single hand to hold the device and simultaneously rotate the outlet tube without use of the second hand of the dentist. The stated advantage was that the outlet tube can be rotated to allow the discharge stream from the powdering device to be aimed at various tooth surfaces without tilting the powder reservoir. Tilting the powder reservoir in the powdering device was thought to increase the risk of clumping the powder. Some embodiments of the Lawler device would include a valve on the powder container to allow the dentist to control the flow of fluid and powder with the hand holding the powdering device. Often a second foot controlled valve would be used in combination with the valve on the powder container. A device based on the Lawler patent is sold under the name PowderMeister™ by Powder Meister, Inc. of Bloomington, Ind.
Problems with Prior Art Solutions
The PowderMeister™ device requires an adjustment process each time it is used. The process includes closing the valve on the container using a thumbscrew so that no air can go into the powder container. Next, the foot control for the pressurized air is fully depressed. With the foot control remaining depressed, the thumbscrew is used to slowly open the valve on the container until the powder begins to flow. It is suggested that the initial spraying of powder within the mouth be directed to a tooth adjacent to the tooth to be powdered for imaging. This allows the clumps of powder to be discharged somewhere other than on the target tooth. Some clumps are attributed to storing the PowderMeister™ on its side or upside down so that excess powder enters the powdering tube. Water in the pressurized source of air poses a problem with the PowderMeister™ as the water will cause the powder to clump.
A second problem area with the PowderMeister™ device is the thumbscrew controlled air valve on the container. The amount of powder applied to the tooth is very sensitive to the position of the thumbscrew. That is, very little movement of the thumbscrew is needed to effect a change in the powder flow. Some dentists find that thumbscrews turn too freely. One corrective trick is to apply Super Glue™ to the threads of the thumbscrew air regulator to keep the thumbscrew from rotating too easily.
It is an object of this invention to provide a powdering device that is adapted to work with a valve that can be operated with one hand to apply a precise amount of airflow into the powder container.
It is an object of this invention to provide a powdering device that is easy to store in an upright position so that powder clumps do not form from non-upright storage.
It is an object of this invention to eliminate powder clumping caused by moisture in the pressurized air supply.
It is an object of this invention to allow the precision controlled dry air supply to be used in dental steps other than powdering to allow the dentist the option of purchasing less equipment.
It is an object of this invention to allow for quick changes between an air delivery function and the function of providing a dry air supply to the powdering device.
It is an object of this invention to provide these advantages while providing a device that is ergonomic such that is provides both accurate placement of powder while being comfortable to use.
These and other advantages of the present invention are apparent from the drawings and the detailed description that follows.
BRIEF SUMMARY OF DISCLOSURE
The improved powdering device disclosed herein is a powdering attachment designed to be used in conjunction with an existing piece of dental equipment known as a dry air syringe. The combination of the powdering attachment and the air syringe forms a powdering device. The dry air syringe is an ergonomic device with integral moisture filter designed for one-handed operation by the dentist. A precision valve on the top of the device allows the dentist to control the airflow by pressing with the thumb of the hand holding the air syringe. The powdering attachment is added to the outlet tube of the air syringe. No valve is needed on the powdering attachment. Nothing needs to be set. A foot-operated valve is not needed to turn the airflow on and off. The outlet tube on the powdering attachment rotates against resistance to allow alteration of the placement of the powder through use of the dentist's other hand. The powdering attachment is designed to allow quick removal of the outlet tube so that the outlet tube can be removed for sterilization after each patient.
The powdering attachment is designed to be easily removed from air syringe. Once disconnected from the air syringe, the powdering attachment is easy to store as it does not have an airline attached to it. When not used for powdering, the air syringe can be u
Qualliotine Danny W.
Qualliotine Otto Armand
Daniels & Daniels, P.A.
Flynn Kevin E.
O'Connor Cary E.
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