Flexibly resilient periotome

Abstract

A novel periotome is disclosed for manually cutting periodontal ligaments during a tooth extraction procedure. The periotome carries end tools manufactured from flexible medical grade materials, usually stainless steel. The end tools have flexible cutting blades with serrated edges and use flattened yieldable surfaces to relieve tool tip stresses which occur during exodontic procedures.

Claims

1. (canceled)

2. (canceled)

3. (canceled)

4. A dental instrument comprising: a handle having two ends; a first end tool comprised of a tool stem securely fastened to a first end of said handle, said tool stem protruding outward linearly along the central major axis of the handle, said tool stem having a linear tapered section and a tapered offset section bent away from said central major axis distal to said first handle end, said tapered offset section having a flattened flexibly yieldable section of a first length extending to an end blade angularly offset from the flattened flexibly yieldable section; a second end tool comprised of a tool stem securely fastened to a second end of said handle, said tool stem protruding outward linearly along the central major axis of the handle, said second tool stem having a linear tapered section and a tapered offset section bent away from said central major axis distal to said second handle end, said tapered offset section having a flattened flexibly yieldable section of a second length extending to an end blade angularly offset from the flattened flexibly yieldable section.

5. A dental instrument according to claim 4 wherein the end blade is comprised of flexible material.

6. A dental instrument according to claim 5 wherein the flexible material is stainless steel.

7. A dental instrument according to claim 4 wherein the flattened flexibly yieldable section may be varied in location and extent thereby providing different degrees of flexibility and stress accommodation.

8. A dental instrument comprising: a handle having two ends, a first end tool comprised of a tool stem securely fastened to a first end of said handle, said tool stem protruding outward linearly approximately 14 mm in length along the central major axis of the handle, said tool stem having a linear tapered section approximately 14 mm length and a tapered offset section approximately 14 mm in length bent away approximately 20 degrees from said central major axis distal to said first handle end, said tapered offset section having a flattened flexibly yieldable section of a first length of approximately 5 mm in length, 0.7 mm in thickness and 2.26 mm in width extending to an end blade approximately 17 mm long formed into a flat arrowhead shape which is angularly offset approximately 40 degrees from the plane of the flattened flexibly yieldable section; a second end tool comprised of a tool stem securely fastened to a second end of said handle, said tool stem protruding outward linearly approximately 14 mm along the central major axis of the handle, said second tool stem having a linear tapered section approximately 14mm in length and a tapered offset section approximately 14 mm in length bent away approximately 20 degrees from said central major axis distal to said second handle end, said tapered offset section having a flattened flexibly yieldable section of a second length of approximately 7.5 mm in length, 0.7 mm in thickness and 2.26 mm in width extending to an end blade approximately 17 mm long formed into a flat arrowhead shape which is angularly offset approximately 40 degrees from the plane of the flattened flexibly yieldable section.

9. A dental instrument according to claim 4 wherein each end blade has serrated edges.

10. A dental instrument according to claim 8 wherein each end blade has serrated edges.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a side elevational perspective view of a preferred embodiment of the invention;

[0010] FIG. 2 is an enlarged detail perspective view of the top right end of the inventive instrument shown in FIG. 1;

[0011] FIG. 3 is an enlarged detail perspective view of the lower left end of the inventive instrument shown in FIG. 1;

[0012] FIG. 4 is an enlarged detail perspective view of the top right end of the inventive instrument shown in FIG. 1 rotated forward and pointed downward.

[0013] FIG. 5 is an enlarged detail perspective of the lower left end of the inventive instrument shown in

[0014] FIG. 1 slightly rotated away along the central long axis of the handle.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0015] FIG. 1 illustrates a perspective view of a preferred embodiment of the inventive periotome 10. This example of the inventive periotome 10 comprises a handle 12 having two operative end tools 15 and 16 securely fastened on each end. Each end tool is formed from a single piece of metal, preferably a flexible stainless steel of medical grade. The overall length of the periotome 10 is approximately 180 mm.

[0016] Handle 12 occupies the center portion along the major axis of the periotome and is approximately 106 mm in length and approximately 10 mm in maximum diameter. Two regions on the handle 40 and 42 of roughly 20 mm in length are reduced in diameter to approximately 8.8 mm to accommodate preferences of the dental clinician when manipulating the instrument. A series of annular grooves are provided within regions 40 and 42 along the surface of handle 12 to improve finger grip and comfort.

[0017] As shown in FIGS. 1, 3 and 4, each individual end tool 15 or 16 can be described as having four sections, namely:

[0018] a tool stem section, 18 and 19, respectively, which protrudes outward linearly along a central axis from opposite ends of handle 12;

[0019] a tapered offset section, 20 and 21, respective to each end tool;

[0020] an offset section 20 having a flattened section 24 and an offset section 21 having flattened section 25, respective to each end tool;

[0021] and an offset end blade 22 and an offset end blade 23, respectively, each having arrowhead or spear point shapes and serrations 30 and 31, respectively, on major portions of the perimeters of each blade.

[0022] In this preferred embodiment, the end tools are formed from round stainless steel wire of medical grade and coated for additional hardness with titanium nitride. At the handle 12 end the exposed steel wire stem diameter is approximately 3.15 mm.

[0023] Tool stem sections 18 and 19 are each approximately 14 mm long. The tool stem sections 18 and 19 taper distal to handle 12 to a diameter of approximately 2.50 mm where each is bent in an offset of approximately 20 degrees from the central axis of the periotome handle 12.

[0024] Tapered offset sections 20 and 21 are each approximately 14 mm in overall length measured from the bend where each becomes offset from its respective tool stem section.

[0025] However, a portion of offset sections 20 and 21 are formed into flattened sections 24 and 25, respectively.

[0026] The diameters of tapered offset sections 20 and 21 are approximately 2.0 mm at the locations where they are formed into flattened sections 24 and 25. Flattened sections 24 and 25 are each approximately 0.7 mm in thickness and 2.26 mm in width.

[0027] In the preferred embodiments depicted in the various FIGS., different length flattened areas are shown. The length of flattened section 25 in end tool 15 is approximately 5 mm. The length of flattened section 24 in end tool 16 is approximately 7.5 mm. The longer flattened section in end tool 16 creates a longer lever arm than the corresponding flattened section in end tool 15. As such, and because the tools are made from the same material, end tool 16 is more flexible. It is more flexible in the sense that it is more easily displaced by a similar engaging force or counterforce when in contact with the tooth contours or periodontal ligaments. End tool 15 has a shorter lever arm and will have stiffer characteristics.

[0028] The end blades 22 and 23 of the inventive periotome as shown in FIGS. 1-5 have serrations 30 and 31 respectively along their outside perimeters. Each blade is approximately 17 mm long and formed into a flat arrowhead or spear point shape. Each is approximately 2.5 mm across at its widest part tapering to a point which is approximately 1 mm wide. The thickness across the flat surface of each blade is approximately 0.5 mm. Each blade, 22 and 23, is offset from the central handle axis by approximately 40 degrees in the opposite direction from its respective tapered offset sections (20 or 21).

[0029] In addition, and perhaps best viewed in FIG. 2, each blade is twisted or rotated approximately 45 degrees from its point of offset to enable the clinician to more easily perform cuts along the perimeter of a tooth.

[0030] The serrations along the perimeter of the end blades facilitate the cutting of the periodontal ligamental fibers. In use, the blade of the periotome is inserted into the periodontal ligament space surrounding the external surfaces of the tooth and root. A certain percentage of the ligamental fibers are cut or fractured immediately in the direction the blade is inserted. The serrated edge of the blade stretches and captures additional fibers which fall into the serrated spaces. When the clinician withdraws the blade these additional ligamental fibers are broken. As such the efficiency of the cutting and extraction process is greatly enhanced minimizing damage to surrounding tissue.

[0031] The flexible metallic blade, when directed by the surgeon clinician, will conformably follow the surface of the cementumthe outside of the root of the tooth. The reflected reaction forces from engagement with the periodontal ligaments or the hard surface of the tooth may cause the blade to bend. However, and with specific reference to FIG. 2 and FIG. 3, those forces are deflected by the flexible blade at 155 and by the yieldable offset section 150 of the inventive tool as shown by the graphical indicators in FIGS. 2 and 3. Flattened regions, such as 24 and 25 in FIGS. 1,3,4 and 5 allow for an extensive and varied range of motion in response to manipulation of the blade by the surgeon clinician.

[0032] While the invention has been described with reference to an exemplary embodiment, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or substance to the teachings of the invention without departing from the scope thereof. Therefore, it is important that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the apportioned claims.