DENTISTS'TOOLS SET BACKGROUND OF THE INVENTION Field of the Invention The present invention relates, in general, to dental instruments and, more particularly, to a multipurpose dental instrument, with two mirrors including at least one convex or concave mirror and respectively mounted to both side surfaces of a mirror holder mounted to the first end of the instrument's handle, and a dental attachment, such as a gingival retractor or a gingival cord packer, removably attached to the second end of the handle, and a scale provided at the second end of the handle for measuring the length of a dental pile or a dental reamer, the multipurpose dental instrument being thus used as a measuring instrument during a dental treatment, and allowing a dentist to easily and conveniently perform a dental treatment within a short period of time.

Description of the Prior Art As well known to those skilled in the art, most conventional dental instruments, such as dental mirrors, gingival retractors, and tooth scalers, have been designed as single- purpose instruments. While scaling in a dental hospital, a dentist views the teeth of a patient using a first instrument, such as a dental mirror, draws back the gingival margin using a

second instrument, such as a gingival retractor, and removes calculus and other deposits from the patient's teeth using a third instrument, such as a tooth scaler. That is, dentists must use several instruments during a dental treatment, and so the conventional single-purpose dental instruments are inconvenient to the dentists.

In an effort to overcome such problems experienced in the conventional single-purpose dental instruments, several types of dual-purpose dental instruments, such as a suction apparatus combined with a dental mirror, and a dental mirror combined with a mouth lamp, have been proposed and used in a dental treatment.

For example, Korean Utility Model Registration No. 20- 0226053 discloses a dental mirror combined with a mouth lamp. In this dual-purpose dental instrument, the handle of the mirror part has a triangular cross-section, while the lamp part has a connector provided with an insert hole having a triangular cross- section corresponding to the cross-section of the mirror part's handle. When assembling the two parts into a single body, the mirror part's handle is inserted into the connector of the lamp part. When using the instrument during a dental examination, light radiated from the lamp part is reflected to a target area inside the dental cavity by the mirror part, thus allowing a dentist to effectively view the target area. After using the instrument, the mirror part is removed form the lamp part, and properly disinfected.

Korean Patent Registration No. 10-0227545 discloses a dental mirror combined with both a mouth lamp and a heating unit.

In this instrument, the distal end portion of the handle is

provided with a dental examining unit. This instrument also has a lamp part for radiating light to a target area inside the tooth cavity, a mirror part for reflecting the light from the lamp part to the target area, thus allowing a dentist to effectively view the target area, and a heating unit for heating the mirror part.

Korean Utility Model Laid-open Publication No. 98-063472 discloses a dental suction mirror. This suction mirror is designed such that it is easy to remove any deposits from the interior of its head, in addition to being light in its weight and semi-permanently maintaining the durability of a reflecting material coated on the back surface of the mirror.

However, such conventional dual-purpose dental instruments are problematic as follows, even though they are fabricated by assembling a mirror part with a lamp part or a suction apparatus.

That is, it is necessary for a dentist to use another single- purpose instrument, such as a gingival cord packer used for packing the gingival cords into the gums or a gingival retractor for drawing back the gingival margin, in addition to the dual- purpose dental instrument during a dental treatment.

Furthermore, the dentist must use a measuring instrument for measuring the length of dental piles or dental reamers typically used in nerve treatments of teeth, and so the dentist separately purchases such length measuring instruments.

During a dental treatment, a dentist typically uses a dental mirror for viewing the narrow surfaces of teeth or tongue, and pulling the tongue to a side so as to perform the treatment without being hindered by the tongue. Most conventional dental

mirrors are one-sided mirrors each typically having one reflecting surface on one side of a mirror holder, and so a dentist using such a one-sided dental mirror cannot view opposite parts inside the dental cavity at the same time. In addition, the reflecting surface of such a one-sided dental mirror is positioned to form an angle relative to the handle, and so it is very difficult to view the dental cavity's part under the tongue using such a one-sided dental mirror.

In an effort to overcome such a problem experienced in the conventional one-sided dental mirrors, a double-sided dental mirror having two reflecting surfaces on both sides of its mirror holder has been proposed and used. An example of such double- sided dental mirrors is disclosed in Korean Utility Model Registration No. 20-0247674, and is shown in Fig. 1 of the accompanying drawings of this invention. As shown in the drawing, the double-sided dental mirror comprises a handle 100 which is assembled with a mirror holder shank 102 through a screw-type engagement. A ring 104 is formed at the tip of the shank 102 while forming an angle between the shank 102 and the plane of the ring 104. Two reflecting surfaces 103 are set on both sides of the ring 104, respectively.

The above double-sided dental mirror with two reflecting surfaces allows a dentist to view desired opposite parts inside the dental cavity at the same time while rotating the dental mirror in a desired direction inside the dental cavity. The double-sided dental mirror is thus more effective than a conventional one-sided dental mirror, which only allows a dentist to view one part of the dental cavity at a time. However, the

two reflecting surfaces of the conventional double-sided dental mirror are flat surfaces, which do not allow a dentist to effectively or clearly view complex or composite damages of teeth during a dental treatment. It is thus necessary to provide a multipurpose dental instrument designed to be selectively used as either of the above-mentioned various functional instruments as desired.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a multipurpose dental instrument, which is designed to be selectively used as either of a variety of functional instruments as desired.

Another object of the present invention is to provide a multipurpose dental instrument, which has two mirrors including at least one convex or concave mirror and respectively mounted to both side surfaces of a mirror holder, thus allowing a dentist to quickly and properly perform a dental examination, and eliminating dissatisfaction of patients caused when dentists rotate conventional dental mirrors inside the patient's dental cavities.

In order to accomplish the above objects, an embodiment of the present invention provides a multipurpose dental instrument, comprising: a longitudinal handle having a polygonal cross- section; a mirror holder attached to a first end of the handle while forming a predetermined angle between the handle and the

mirror holder, with two mirrors respectively mounted to both side surfaces of the mirror holder; an attachment holder mounted to a second end of the handle at a position opposite to the mirror holder, with a mounting groove formed at the outside end of the attachment holder; and a dental attachment used for a dental treatment and removably attached to the mounting groove of the attachment holder, whereby the two mirrors of the mirror holder include at least one convex or concave mirror.

Another embodiment of the present invention provides a multipurpose dental instrument, comprising: a longitudinal handle having a polygonal cross-section ; and a mirror holder attached to a first end of the handle while forming a predetermined angle between the handle and the mirror holder, with two mirrors respectively mounted to both side surfaces of the mirror holder, whereby the handle has a scale at a second end thereof for measuring a length, with a seating groove axially formed alongside the scale, and the two mirrors of the mirror holder include at least one convex or concave mirror.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Fig. 1 is a perspective view of a conventional single- purpose dental instrument, so-called"a dental mirror";

Fig. 2 is a perspective view of a multipurpose dental instrument in accordance with the primary embodiment of the present invention ; Fig. 3 is an exploded perspective view of the multipurpose dental instrument, with a mirror holder specifically bent at its shank in accordance with a modification of the primary embodiment of this invention; Figs. 4a to 4d are exploded side views, each showing two mirrors attached to both side surfaces of the mirror holder of the dental instrument in accordance with a modification of the primary embodiment of this invention ; Fig. 5 is a perspective view of a gingival retractor, which is used as a dental attachment and removably attached to the attachment holder of the dental instrument according to this invention ; Fig. 6 is a perspective view of a gingival cord packer, which is used as a dental attachment and removably attached to the attachment holder of the dental instrument according to this invention ; Fig. 7 is a perspective view of another type of gingival cord packer, which is used as a dental attachment and removably attached to the attachment holder of the dental instrument according to this invention; Figs. 8a to 8d are perspective views showing a variety of mirror holders selectively attached to the handle of the dental instrument according to this invention ; and Fig. 9 is an exploded perspective view of a multipurpose dental instrument in accordance with the second embodiment of the

present invention.

DETAILED DESCRIPTION OF THE INVENTION Reference now should be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components.

Fig. 2 is a perspective view of a multipurpose dental instrument in accordance with the primary embodiment of the present invention. Fig. 3 is an exploded perspective view of the multipurpose dental instrument, with a mirror holder specifically bent at its shank in accordance with a modification of the primary embodiment of this invention. Figs. 4a to 4d are exploded side views, each showing two mirrors attached to both side surfaces of the mirror holder of the dental instrument in accordance with a modification of the primary embodiment of this invention. Fig. 5 is a perspective view of a gingival retractor, which is used as a dental attachment and removably attached to the attachment holder of the dental instrument. Fig. 6 is a perspective view of a gingival cord packer used as a dental attachment of this instrument. Fig. 7 is a perspective view of another type of gingival cord packer used as a dental attachment of this instrument. Fig. 8 is a perspective view showing a variety of mirror holders selectively attached to the handle of this dental instrument. Fig. 9 is an exploded perspective view of a multipurpose dental instrument in accordance with the second embodiment of this invention.

As shown in Figs. 2 and 3, the multipurpose dental

instrument of this invention comprises a longitudinal handle 10, and a mirror holder 20 removably attached to the first end of the handle 10. The handle 10 has a polygonal cross-section, which effectively prevents a slippage of the handle 10 from a dentist's hand and relieves hand fatigue even when a dentist performs a dental treatment with the instrument for a lengthy period of time. An example of the polygonal cross-sections of the handle 10 is a hexagonal or octagonal cross-section. The mirror holder 20 is designed to form a predetermined angle between the handle 10 and the mirror holder 20 when the holder 20 is attached to the handle 10. The removable attachment of the mirror holder 20 to the handle 10 is accomplished by screw-type engagement of external threads of the holder 20 with internal threads of the handle's first end. Two mirrors are respectively mounted to both side surfaces of the mirror holder 20. In the embodiment of Fig.

2, the mirror holder 20 has a straight shank. However, it should be understood that the shank of the mirror holder may be specifically bent as shown in Fig. 3. In comparison with the instrument having the mirror holder 20 with the straight shank of Fig. 2, the instrument having the mirror holder 21 with the bent shank of Fig. 3 is more advantageous in that it allows a dentist to more effectively use it without interference between the mirror holder 21 and the gums during a dental treatment. The following description of the primary embodiment of this invention will be expressed with reference to the instrument of Fig. 2.

The mirror holder 20 of this instrument has at least one convex or concave mirror as shown in Figs. 4a to 4d. In a modification of Fig. 4a, the mirror holder 20 has one flat mirror

35 on its first side surface, and one convex mirror 30 on its second side surface. In another modification of Fig. 4b, the mirror holder 20 has one convex mirror 36 on its first side surface, and one flat mirror 31 on its second side surface. In a further modification of Fig. 4c, the mirror holder 20 has one flat mirror 35 on its first side surface, and one concave mirror 32 on its second side surface. In still another modification of Fig. 4d, the mirror holder 20 has one convex mirror 36 on its first side surface, and one concave mirror 32 on its second side surface.

In the preferred embodiments of this invention, the mirror holder 20 has a ring 40 at the tip of its shank, and the two mirrors are set in the ring 40. In the present invention, the two mirrors set in the ring 40 may be fixed to the ring 40 using a bonding agent. Alternatively, an annular flange is formed along each of the top and bottom edges of the ring 40 to form a U-shaped cross-section of the ring 40, so that two flanges of the ring 40 hold the circular edges of the two mirrors set in the ring 40. In such a case, it is possible to reliably hold the two mirrors in the ring 40 without using any bonding agent.

As shown in Figs. 2 and 3, an attachment holder 50 is mounted to the second end of the handle 10 at a position opposite to the mirror holder 20, with a dental attachment used for a dental treatment and removably attached to the attachment holder 50. As best seen in Fig. 3, the second end of the handle 10 has external threads 12, while the facing end of the attachment holder 50 has internal threads 59 engaging with the external threads 12 of the handle 10. The outside end of the attachment

holder 50 is domed to form a hemispherical end. A mounting groove 52 axially extends from the hemispherical outside end of the attachment holder 50 inward to a predetermined length, and is terminated by a circular seating hole 53 at its inside end. Due to the mounting groove 52 with the seating hole 53, it is possible to attach a desired dental attachment to the attachment holder 50. That is, each dental attachment has a shank terminated by a spherical ball 68 such that the attachment is removably mounted to the attachment holder 50 by the ball 68 seated into the seating hole 53 and the shank seated in the mounting groove 52. In order to firmly hold a desired dental attachment attached to the attachment holder 50, a semicircular cutout 13 is formed at the externally threaded second end of the handle 10. When the internal threads 59 of the attachment holder 50 are fully tightened to the external threads 12 of the handle 10 after seating the shank of a desired dental attachment into the mounting groove 52 and the ball 68 into the seating hole 53, the edge of the semicircular cutout 13 of the handle 10 comes into close contact with the ball 68 of the dental attachment while biasing the ball 68 toward the hemispherical outside end of the attachment holder 50. It is possible to replace an existing dental attachment of the instrument with another one when necessary, adjust the angle of a dental attachment relative to the attachment holder 50 as desired, and firmly hold the dental attachment to the attachment holder 50.

Fig. 5 shows a gingival retractor 60, which is used as a dental attachment removably attached to the attachment holder 50.

As shown in the drawing, the gingival retractor 60 has a shank

61, with a gingival retracting blade formed at the first end of the shank 61. The gingival retracting blade is curved to form an arc-shaped cross-section, and used for drawing back the gingival margin during a dental treatment. The above shank 61 is terminated by a spherical ball 68 at its second end, and so the gingival retractor 60 is removably mounted to the attachment holder 50 by the ball 68 seated into the seating hole 53 of the attachment holder 50 and the shank 61 seated in the mounting groove 52 of the holder 50.

Figs. 6 and 7 show two gingival cord packers 70 and 74, each used as a dental attachment removably attached to the attachment holder 50 of this invention. As shown in the drawings, each of the two gingival cord packers 70 and 74 has a shank at its first end, with a spherical ball 68 formed at the end of the shank, in the same manner as that described for the gingival retractor 60. Each of the cord packers 70 and 74 is thus removably mounted to the attachment holder 50 by the ball 68 seated into the seating hole 53 of the attachment holder 50 and the shank seated in the mounting groove 52. The gingival cord packer 70 of Fig. 6 also has a packer blade at its second end.

Different from the cord packer 70 of Fig. 6, the cord packer 74 of Fig. 7 also has packer teeth 76 formed along the outside edge of the packer blade. In each of the gingival cord packers 70 and 74, the packer blade is formed by the wide body of each packer.

Figs. 8a to 8d are perspective views showing a variety of mirror holders selectively attached to the handle 10 of the dental instrument according to this invention. The mirror holder 20 of Fig. 8a has a circular ring for holding two mirrors. The

shape of this mirror holder 20 is the same as that of Fig. 2.

The mirror holder 22 of Fig. 8b has a circular ring smaller than that of Fig. 8a. The mirror holder 23 of Fig. 8c has an oval ring for holding two mirrors. The mirror holder 21 of Fig. 8d has a circular ring and a bent shank. The shape of this mirror holder 21 is the same as that of Fig. 3. As described above, the shape of the ring and shank of the mirror holder used with the multipurpose dental instrument of this invention may be freely designed as desired.

Fig. 9 is an exploded perspective view of a multipurpose dental instrument in accordance with the second embodiment of the present invention. As shown in the drawing, the dental instrument according to the second embodiment uses a mirror holder 20 having the same shape as that of the primary embodiment of Fig. 2. However, the second end of the handle 15 according to this embodiment is not designed to hold any attachment holder, different from the primary embodiment, but has two scales 80 and 84. A seating groove 82 is axially formed alongside the scales 80 and 84. When measuring the length of a dental pile or a dental reamer using the instrument, the pile or the reamer is axially seated in the groove 82, so that a dentist easily and simply measures the length.

The operational effect of the multipurpose dental instrument of this invention will be described herein below with reference to the drawings.

The multipurpose dental instrument of this invention has a mirror holder, which is removably attached to the first end of the instrument's handle 10 and has two mirrors including at least

one convex or concave mirror. That is, the mirror holder of the instrument has a ring, with one convex or concave mirror and one flat mirror set on both side surfaces of the ring. The multipurpose dental instrument is thus used as a double-sided dental mirror. When using the instrument as a dental mirror during a dental treatment, a dentist views a target area of the patient's teeth using one mirror of the mirror holder while restraining the patient's tongue using the mirror holder, thus performing a dental examination. This instrument also allows the dentist to view the teeth positioned at an area which does not allow the dentist to easily view the teeth using a conventional dental mirror. Since this instrument has one convex or concave mirror at the mirror holder, the dentist effectively and clearly views complex or composite damages of the teeth during a dental treatment. Of course, the dentist uses this instrument while selectively attaching several mirror holders, which have different mirrors, differently shaped rings, and differently shaped shanks, to the first end of the handle 10 as desired during a dental treatment. The removable attachment of the mirror holder to the first end of the handle 10 is accomplished by screw-type engagement of the external threads of the mirror holder with the internal threads of the handle 10 as shown in Fig. 3.

After the dental examination for the teeth and gums, the dentist treats the damaged teeth using a dental attachment, such as a gingival retractor or a gingival cord packer mounted to the attachment holder 50 of the dental instrument. When attaching a desired dental attachment to the dental instrument, the

attachment is primarily seated in the holder 50 by seating the shank of the attachment into the mounting groove 52 of the holder 50 and the ball 68 into the seating hole 53. Thereafter, the internal threads 59 of the holder 50 are fully tightened to the external threads 12 of the handle 10, and so the edge of the semicircular cutout 13 of the handle 10 comes into close contact with the ball 68 of the dental attachment while biasing the ball 68 toward the hemispherical outside end of the holder 50. It is thus possible to firmly attach the desired dental attachment to the instrument.

When using the multipurpose dental instrument of Fig. 9 as a dental mirror during a dental treatment, the operational effect of the instrument remains the same as that described for the instrument of the primary embodiment. Different from the instrument of the primary embodiment, this instrument of the second embodiment is also used for measuring the length of a dental pile or a dental reamer using the seating groove 82 and the two scales 80 and 84 provided at the second end of the handle 10.

In a detailed description, the multipurpose dental instrument of this invention is integrated with a dental mirror, a length measuring unit, and a dental attachment, such as a gingival retractor or a gingival cord packer. This instrument thus allows a dentist to easily, conveniently and quickly perform a dental treatment using one integrated dental instrument without being required to separately use the dental mirror, the gingival retractor, the gingival cord packer, and the length measuring unit which are designed as single-purpose instruments.

As described above, the present invention provides a multipurpose dental instrument, which is selectively combined with a variety of dental mirrors and a variety of dental attachments. This multipurpose dental instrument is designed to allow a dentist to easily and quickly replace an existing mirror and/or an existing dental attachment with another mirror and/or another attachment as desired. This instrument is also designed to allow the dentist to adjust the angle of the mirror or the attachment relative to the handle as desired. The instrument of this invention has a structure capable of easily and firmly attaching a desired attachment to the handle.

The multipurpose dental instrument of this invention has two mirrors including at least one convex or concave mirror, and so it is used as a double-sided dental mirror and allows a dentist to properly and quickly perform a dental examination.

This instrument also eliminates dissatisfaction of patients caused when dentists rotate conventional one-sided dental mirrors inside the patient's dental cavities.

Although a preferred embodiment of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.