Tooth reduction measuring tool and methods

#This invention relates generally to the field of dentistry, and in particular to the reduction of teeth to facilitate placement of a dental prosthetic device, such as a crown. Or specifically, the invention is related to a dental tool and methods for measuring the amount of tooth reduction.

#Artificial dental crowns are used as a restoration for teeth, and are particularly useful when teeth have been broken, have been weakened by decay, or have one or more large fillings. Dental crowns are constructed to fit over the remaining portion of the tooth to make the tooth stronger and provide the tooth with the shape and contour of the natural tooth. As such, crowns are often referred to as caps.

#Dental crowns are typically fabricated outside the patient's mouth and then installed in the mouth. The manner of installation may vary depending on the nature of the crown. For example, full crowns are employed to cover the entire surface of a tooth as well as the sides of the tooth. Partial crowns are inlays which cover the top surface and portions of the sides. Inlays are employed to cover central portions of the top surface and may also extend partially onto the sides. Finally, veneers are used to cover a side surface of a tooth. A detailed discussion of how such dental crowns may be placed onto a tooth is set forth in U.S. Pat. No. 5,525,059, the complete disclosure of which is herein incorporated by reference.

#FIG. 1 is a top view of one embodiment of a tooth reduction measuring tool according to the invention.

#FIG. 2 illustrates another embodiment of a tooth reduction tool having an angled flexible loop according to the invention.

#FIG. 3 is a side view of a portion of a patient's jaw showing a middle tooth that has been reduced in preparation for receiving a crown.

#The invention provides various tools and techniques for determining the amount of tooth reduction when preparing a tooth to receive an artificial dental crown. Once the tooth is appropriately prepared, the tooth may be fitted with a wide variety of dental crowns that are constructed of a wide variety of materials, such as those previously described in the background section of this application. Hence, the invention is not intended to be limited for use with only a specific type of dental crown. Further, the invention may also be used with a wide variety of techniques and tools that are employed to alter the shape of the tooth during preparation of the tooth. Hence, the invention is also not intended to be limited to a specific method for altering the shape and/or size of the tooth.

#To measure the amount of tooth reduction, the invention utilizes a flexible loop that is positioned over the reduced tooth while the patient's mouth is open. The patient is then instructed to bite down and the loop is manipulated in an attempt to slide the loop between a gap defined by the reduced tooth and the opposing tooth. The thickness of the flexible loop may be selected such that if it cleanly passes through this gap, an appropriate amount of material has been removed. Conveniently, loops of different sizes may be used in an iterative process to prevent the over-reduction of a tooth. For example, a smaller sized loop may initially be used. Once this cleanly passes through the gap, a larger sized loop may be attempted to see if it will pass through the gap. The second loop may be of the desired thickness so that if the second loop fails to be pulled through the gap, the dentist may remove additional material until the second loop passes between the gap.

#Once the tooth has been appropriately prepared, the crown may be fabricated and coupled to the tooth using techniques known in the art. As such, the invention is not intended to be limited to a specific technique for forming and attaching a crown, but may use any of the techniques known to those skilled in the art.