Field of the Invention

This invention relates to a dental instrument for the measurement of the angle of dental implant abutment as compared to its adjacent teeth and the method for making such measurements. More particularly it relates to a dental instrument having generally long longitudinal arms connected on one end, the longitudinal arms being movable in side ways, an angle display portion and its use for making measurements.

Background and prior art of the Invention

During the production of dental implant prostheses, the dental technician obtains an impression of the oral cavity and surroundings, usually of the toothless of partially anodont jaw obtained from the impression for fabrication of prosthesis.

Conventionally, dental implant analogues are positioned in the impression to simulate the exact position of the implant in the oral cavity. Abutments are selected for the restorations based on the required alignment of the restoration with the adjacent and opposing teeth.

The dental technician/ dentist select the angulation of the implant abutment based on the wax up of the definitive restoration. The implant abutment with the desired angulation is then obtained from the manufacturer or custom made for the fabrication of implant retained fixed dental prosthesis.

In case where dental prostheses are fabricated over multiple implants the implant abutments need to be oriented parallel to each other. Based on their relationship with each other and with adjacent teeth the angulations of the implant abutments are selected.
The document US 6945779 describes a tooth inclination apparatus for allowing assessment of the angle of inclination of an incisor tooth or cast thereof includes a plane element providing a flat datum surface for resting against e.g. the upper molars in the maxillary plane. From the underside of the plane element projects a protractor portion with a graduated angular scale which measures the angular deviation of an indicator pin pivoted to the plane member and moved to contact the tooth whose inclination is being measured. Other mechanical or electro-optic devices may be used to determine the inclination of the incisor relative to the datum surface.

In view of this described diversity, the invention provides an angle measuring instrument for the dental implant abutment that is simple to handle and yet capable of providing multiple measuring parameters which none of the prior art documents have disclosed.
Object of the invention

It is an object of the present invention to overcome the drawbacks of the prior art and to provide a measuring device which can quickly and accurately measure the desired dental implant abutment angulation intra-orally as well as extra-orally.

It is a further object of the present invention to provide a measuring device which provides an accurate reading from any angle.

It is yet another object of the present invention to provide a method for measuring the desirable angle of the dental implant abutment using the novel dental instrument.

Summary of the Invention

These and other related objects are achieved by a measuring device having a measured angle indicating arm which is used to indicate the desirable angle of a dental implant abutment. The measuring device is placed on the platform of the dental implant to be measured intra-orally or implant analogue extra-orally with the handle of the measuring device extending along the long axis of the dental implant. The movable arm can be adjusted to the desired angulation in relation to the adjacent and opposing teeth. The measuring device is fixed to the platform of a dental implant or analogue. The angle
indicating arm will then indicate the desired dental implant abutment angulation so that an appropriate implant abutment may be selected.

Statement of the Invention

A dental instrument for the measurement of desirable implant abutment angulation in comparison to the adjacent tooth or dental implant abutment comprises

(A) Two longitudinally elongated hands connected at the rear end wherein said hands comprise a first movable elongated hand and a second immovable elongated hand.

(B) An angle indicating protractor portion comprising the pre determined etched angles connected to one end of the second immovable elongated hand.

(C) A screw means for variably connecting the said first movable elongated hand with the said second immovable elongated hand at the end opposite to the protractor arm.

(D) A hexagonal extension arm at the rear end of the immovable elongated
hand, opposite to the protractor arm for connecting the abutment to implant connection

A method for the angle measurement of the dental implant abutment in comparison to its adjacent tooth comprises the steps of

(A) Positioning the rear end of the said dental instrument comprising the said hexagonal extension arm to the implant connection of which abutment is to be selected.

(B) Moving the said first movable elongated hand over the said protractor arm after detightening the said screw means.

(C) Determining the position of the said first movable elongated hand upon the protractor arm of the second movable elongated hand in relation to the adjacent and opposing teeth.

(D) Manually tightening the said screw means for fixing the position of the first movable elongated hand upon the said protractor arm with angle display means.

(E) Determining the desired implant abutment angulation upon viewing the position of the tapered end of the said first movable elongated hand over the said protractor arm with angle display means.

Brief Description of the Drawings

Fig. 1 illustrates the constructional features of the novel dental implant abutment angle determining dental instrument.

Fig. 2 illustrates the method of using the novel dental instrument for the determination of angle for selection of dental implant abutment.

Detailed description of the Drawings

The differences between the prior art apparatus and instant invention lies in that the abutment angle finder gives the relative angle of the dental implant in relation to adjacent teeth/adjacent implants for the determining the ideal abutment position. The device is useful for implant treatment planning, selection of abutments and restoration of dental implants and the aim of this invention to provide a valid, reliable, simple, inexpensive and non-invasive, intra oral method and apparatus for measuring angle of implant relative to adjacent teeth/implant for determining the ideal abutment position. The implant abutment angle finder is placed on the dental implant connection (hex or othenwise), the movable arm is moved to desired position, measurement taken on calibrated protractor arm and the implant abutment is chosen based on the obtained measurement and finally the restoration of implant is executed. This device is particularly useful in situations in which dental implants are placed at extreme and even undesirable angles. The additional use is that it can be used extra orally also in the laboratory whereas the cited invention measures angle of implants in reference to the adjacent and opposing teeth for designing the prosthesis.

Fig.1 illustrates a measuring device having a measured angle indicating arm which is used to indicate the desirable angle of implant abutment. The measuring device is connected to the platform of the implant to be measured with the measuring device extending into the implant connection. The angle indicating arm can be adjusted to determine the desired position of implant abutment. It will then indicate the desirable angulation of the implant abutment so that an appropriate angled abutment may be selected. The screw is tightened after determining the desirable abutment angulation of the abutment to secure the movable arm against the protractor arm in the desired angle.
When the measuring device is used in the oral cavity, the measuring device is connected to the implant to be restored after removing the cover screw or the healing abutment. The movable arm is used to determine the desired angulation of the implant abutment to be used for the prosthesis.

The device for measuring the abutment angulation or other object includes two longitudinally extending hands having a first hand, a second hand, protractor angle indicating arm and a extending arm for connecting to the implant connection. The first hand is disposed at the first handle and has an aperture for connecting the hollow interior to the exterior of the second hand through the second handle. The second hand is adjustable to locate the aperture at a particular angle with respect to the longitudinal axis of the first handle. A tightening screw means is provided which has rotatable screw ends. The first and second hand is located exteriorly of the handle and forms an extension arm at the rear end to be placed into the implant connection.

The ends of the hands pass through the aperture of the head portion into the hollow interior, with one end attached to the handle. Tightening screw means are operatively connected to the handles of the first and second hands for fixing the angle indicating movable arm securely to the immovable arm. Angle display means are mounted on the exterior of the second handle and are coupled to a tightening means for indicating the angle of the abutment to be measured. An immovable hexagonal (or otherwise) extension is present at the rear end of the second hand for connecting to the implant connection.
Calibration means are provided for calibrating on the angle display means by tapering the free end of the first hand. Adjusting the second hand through the tightening screw means shows the desired angulation of the abutment in comparison with the adjacent teeth implant abutment.

The first and second hands and the tightening screws are removable for sterilization. The hand portion is adjustable to locate the tapering end of the first hand against the calibrated arm which has calibration from 0 to 45 degree with individual lines at an interval of 5 degree The aperture may be off-set at 0° without being adjustable. The protractor arm for angle display section forms a single piece device with inter proximal gauge angle and the first movable hand tapers in a distal manner from the circular section.

The tightening screw means includes a lever pivotally mounted on the first handle, having an end located within the hollow interior and attached to the other end of the second handle. Pivotal movement of the lever retracts the end of the second hand into the hollow interior, to tighten the arm against immovable second arm. The display means includes calibrated angle displays mounted on front sides of calibrated protractor arm..
A dental instrument for the angle measurement of the implant abutment in comparison to its adjacent tooth or dental implant comprises two longitudinally elongated hands connected at the rear end wherein said hands comprise a first movable elongated hand and a second immovable elongated hand, a calibrated protractor arm comprising the pre determined etched angles connected to one end of the second immovable elongated hand and a screw means for variably connecting the said first movable elongated hand with the said second immovable elongated hand at the end opposite to the calibrated protractor arm.

The said first movable elongated hand is tapered at the top side end for the precise indication of the desired angle of the abutment. It moves over the said calibrated protractor angle display means over the range of 0 to 45degree and is fixed to a specific position by means of the said screw means. The said second immovable elongated hand comprises the calibrated protractor angle display arm connected at the upper end and a hexagonal (or otherwise) extension arm at the rear end for connecting to the implant connection. The first movable elongated hand is connected at the lower end of the second arm by the said screw means. The said calibrated protractor angle display arm comprises angles ranging from 0 to 45 degrees pre etched upon the surface and the position of the said first movable elongated hand is fixed at pre determined locations by means of the said pivotal screw means.

Fig. 2 illustrates the method of using the novel dental instrument for the determination of the implant abutment angle. The method for the angle measurement of the abutment in comparison to its adjacent tooth comprises the steps of positioning the rear end of the said dental instrument comprising the hexagonal extension arm into the implant connection that is to be evaluated. Moving the said first movable elongated hand over the said calibrated protractor angle display means after de tightening the said screw means will determine the position of the said first movable elongated hand upon the said movable elongated hand upon the said calibrated protractor angle display means.
The extension arm in the rear end of the second immovable arm is shaped like an hexagonal connection of the implant. Alternatively it can be designed with internal connection /internal octagon etc to suit the connection design of various implant systems.
It will be obvious to a person skilled in the art that with the advance of technology, the basic idea of the invention can be implemented in a plurality of ways. The invention and its embodiments are thus not restricted to the above examples but may vary within the scope of the claims.

Further the above-described embodiments of the present invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.

I claim

1) A dental instrument for the measurement of dental implant abutment angle in comparison to its adjacent tooth or implant abutment comprises

(A) Two longitudinally elongated hands connected at the rear end wherein said hands comprise a first movable elongated hand and a second immovable elongated hand.

(B) A calibrated protractor comprising the pre determined etched angles connected to one end of the second immovable elongated hand.

(C) A hexagonal extension arm at the rear end of the said second immovable elongated hand for connecting to the implant connection.

(D) A screw means for variably connecting the said first movable elongated hand with the said second immovable elongated hand at the end opposite to the calibrated protractor arm.

2) The dental instrument for the measurement of the dental implant angulation abutment in comparison to its adjacent tooth or dental implant as claimed in claim 1 wherein the said first movable elongated hand

(A) Is tapered at the top side end for the precise indication of the abutment angle.

(B) Moves over the said calibrated protractor angle display means over the range of 0 to 45 degrees.

(C) The two arms are fixed to a specific position by means of the said screw means.

3) The dental instrument for the desired angle measurement of the implant abutment in comparison to its adjacent tooth as claimed in claim 1 wherein the said second immovable elongated hand comprises

(A) The calibrated protractor angle display arm connected at the upper end.

(B) Hexagonal extension arm for connecting to the implant at the rear end.

(C) The first movable elongated hand connected at the lower end by the said screw means.

4) The dental instrument for the angle measurement of the implant abutment in comparison to its adjacent tooth or dental implant abutment as claimed in claim 1
0 to 45 degrees pre etched upon the surface.

5) The dental instrument for the measurement of the desired abutment angle in comparison to its adjacent tooth as claimed in claim 1 wherein the position of the said first movable elongated hand is fixed to the implant at pre determined locations by means of the said hexagonal extension arm of the second immovable arm means.

6) A method for the desired implant abutment angle measurement in comparison to its adjacent tooth comprises

(A) Positioning the rear end of the said dental instrument comprising the said hexagonal extension arm into the implant connection of the implant to be evaluated.

(B) Moving the said first movable elongated hand over the said calibrated protractor angle display means after de tightening the said screw means.

(C) Determining the position of the said first movable elongated hand upon the said second immovable elongated hand that fits into the implant connection of the implant to be evaluated.

(D) Manually tightening the said screw means for fixing the position of the first movable elongated hand upon the said calibrated protractor angle display means.

(E) Determining the desirable abutment angle upon viewing the position of the tapered end of the said first movable elongated hand over the said calibrated protractor angle display means.

7) The method for measurement of the implant abutment in comparison to its adjacent tooth or implant abutment as claimed in claim 6 wherein the said first movable elongated hand

(A) Is tapered at the top side end for the precise indication of the implant abutment angle.

(B) Moves over the said calibrated protractor display means over the range of 0 to 45 degrees.

(C) The two arms are fixed to a specific position by means of the said screw means.

8) The method for the measurement of the desired abutment angle in comparison to its adjacent tooth or implant abutment as claimed in claim 6 wherein the said second immovable elongated hand comprises

(A) The calibrated protractor angle display arm connected at the upper end.

(B) A hexagonal extension arm at the rear end for the connecting to the implant to be evaluated.

(C) The first movable elongated hand connected at the lower end by the said screw means.

9) The method for the measurement of the desired abutment angle in comparison to its adjacent tooth or implant abutment as claimed in claim 6 wherein the said calibrated protractor angle display arm comprises angles ranging from 0 to 45 degrees pre etched upon the surface.

10) The method for the measurement of the desired implant abutment angle in comparison to its adjacent tooth or implant abutment as claimed in claim 6 wherein the position of the said first movable elongated hand is adjusted to the desirable angulation and then fixed to the second arm at this determined position by means of the said pivotal screw means.