Dental restoration dowel positioner

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a preferred embodiment of the present invention illustrated supporting a pair of dowels in a dental impression;

FIG. 2 is a sectional view taken along line 2—2 of FIG. 1, illustrating the vibrator in operation;

FIG. 3 is a sectional view taken along line 3—3 in FIG. 2;

FIG. 4 is a front elevational view of a dowel supporting bracket forming part of the improved apparatus;

FIG. 5 is a view taken along line 5—S in FIG. 4; FIG. 6 is a view taken along line 6—6 in FIG. 4; FIG. 7 is a fragmentary view of another form of dowel support bracket supporting a different type of dowel; and

FIG. 8 is a perspective view of a dowel carrying die section produced with the improved apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT ⁿ?^{W tO the drawin}S^s> and particularly FIGS. 1 to 6 thereof which illustrate a preferred embodiment of the present invention, the rererence numeral 10 generally designates the improved apparatus which includes a rectangular base plate 11 formed of steel or other highly magnetic material and is provided at its corners with depending, preferrably rubber foot pieces 12. Four vertical upwardly directed posts 13 are secured to base plate 11 inwardly of respective corners ot the base plate and terminate at their tops in short coaxial coupling pins 14. Supported atop the posts 13 is a rectangular mount plate 16 of similar configuration but of lesser dimensions than base plate 11, the mount Fh ^te J⁶ ,^ha,^{vlng circ}ular apertures in the corners thereof which are engaged by rubber grommets. The rubber grommets 17 engage the coupling pins 14 and define vibration absorbing cushions between mount plate 16 and posts 13.

A pair of longitudinally spaced dental pan clamps 18 are positioned along a border of the mount plate and each comprises a bracket 19 including a bottom leg 20

3,753,291

DENTAL RESTORATION DOWEL POSITIONER

BACKGROUND OF THE INVENTION

The present invention relates generally to improvements in dental restoration apparatus and it relates more particularly to an improved apparatus for supporting dowels m accurate orientations and positions in a dental impression attendant to the production of a die therefrom.

A common procedure which is practiced in the production of dental restorations and models, such as crowns, inlays, bridgework and the like involves filling a dental impression tray, generally of U-shaped configuration with a suitable dental impression material such as wax or a hydrocolloid and applying the impression material carrying tray to the subject’s teeth to obtain an accurate impression of the teeth. The prepared impression is then removed and filled with a fluid or plastic casting material which sets to a solid mass to obtain a die from the impression which is then employed in pro- 20 ducmg the desired restoration.

In order to expedite the production of the restoration a dowel is positioned in one or more of the impression tooth cavities and is cast in place in the resultant die to facilitate the removal, handling and replacement of se- 25 lected die sections. It is essential to the proper use of the dowels that they be accurately positioned. To this end the dowel should be centered so as not to protrude or be close to the outer face of the respective die section and should be oriented to be substantially vertical since excessive deviation from such disposition results in the difficult handling of the die sections and an inaccurate and inferior restoration. Many types of devices and apparatus have been employed and proposed for positioning the dowel in the impression, but these devices have been complex and difficult to operate, unreliable and of little versatility and adaptability.

SUMMARY OF THE INVENTION

It is a principal object of the present invention to provide an improved dental restoration apparatus.

Another object of the present invention is to provide an improved apparatus for the positioning of dowels in dental impressions attendant to the production of dies therefrom.

Still another object of the present invention is to provide an improved apparatus for the production of dies with one or more dowels from a dental impression.

A further object of the present invention is to provide an apparatus of the above nature characterized by its reliability, ease, simplicity and convenience of application, accuracy, ruggedness, versatility and adaptability.

The above and other objects of the present invention will become apparent from a reading of the following description taken in conjunction with the accompanying drawings which illustrate preferred embodiments thereof.

In a sense the present invention contemplates the provision of a dental restoration apparatus comprising a base member formed of magnetic material, a mount member positioned on the base member, means for separably supporting a dental impression on the mount member, a permanent magnet coupling member located on and adjustable along the face of the base member and magnetically secured thereto, a universally adjustable bracket mounted on the coupling member and extending above the mount member, and a

3,753,291 superimposed on the underface of mount plate 16 and secured thereto by nuts and bolts. An upwardly inwardly inclined arm 21 extends from the outer end of leg 20 and terminates in an inwardly directed horizontal leg 22 disposed above the border of mount plate 16. A tapped vertical bore is centrally formed in the leg 22 and is engaged by a mating clamp screw 23 having a knob 24 affixed to its upper end. A rubber clamp pad 26 of frusto-conical shape is carried by the bottom of clamp screw 23 and a washer 27 secured to the clamp screw 23 engages the top face of clamp pad 26.

An electrical vibrator 28 of conventional construction is affixed to the underface of mount plate 16 by nuts and bolts 29 engaging registering openings in mount plate 16 and in a flange 30 formed on the vibrator case. The vibrator 28 is connected to a source of current by a plug terminated electrical line 32 provided with a line switch 33.

The member for supporting the dental impression A includes a dental pan 34 of conventional U-shaped, open top and open ended configuration. A coupling bracket is connected to the pan 34 and includes a horizontal leg 36 secured to the medial underface of the pan 34, and an outwardly downwardly inclined arm 37 extending from the leg 36 and terminating in an outwardly directed horizontal leg 38. The pan 34 is supported on and above mount plate 16 by clamping bracket leg 38 between mount plate 16 and clamp pad 26.

One or more universally adjustable dowel support as- ^;semblies 39 are provided for accurately positioning corresponding tubular dowels 40 in desired locations in the impression A attendant to the production of a die B. Each dowel support assembly 39 comprises a magnetic coupling base 41 of known construction which includes a channel shaped section formed of a magnetic material and having a horizontal top web 42 and a pair of depending short opposite legs 43. Nested in the channel and secured to the underface of web 42 is a strong permanent magnet 44, for example of the Al- ⁴⁰nico or ceramic type, which oppositely magnetically includes legs 43.

A cylindrical vertical post 46 is centrally mounted atop the web 42 and terminates at its top in a horizontally directed spherical socket member 47, as seen best ⁴⁵in FIG. 4. A cylindrical arm 48 is provided at its inner end with a ball member 49 which engages socket member 47 to form therewith a ball and socket joint 50, which permits the universal angular adjustment of arm 48 on post 46, while supporting the arm 48 in its adjusted position. The outer end of arm 48 is provided with a ball section 51 of a ball and socket joint 52 similar to ball and socket joint 50, and engages the socket section 53 thereof. A cylindrical pin 54 depends from the socket member 53 and terminates at its top in a peripheral horizontal shoulder 56, the pin 54 being perpendicular to the axis of the socket of socket member 53 and being universally angularly adjustable relative to the arm 48 about joint 52.

Considering now the operation of the improved apparatus 10, a dental impression A is produced in the known manner with the dental pan 34 and one or a pair of the impression carrying dental pans 34 are mounted atop the mount plate 16 by clamping the respective bracket arms 38 between the mount plate 16 and corresponding clamp pads 26 so that the pans 34 are medially positioned above the mount plate 16. Dowels 40 are slipped over pins 54 and are frictionally engaged by the pins 54 and the assemblies 39 are adjusted in position along base plate 11 and are angularly adjusted so that the respective dowels 40 are accurately and properly positioned in selected cavities in the impression A. This dowel positioning procedure is simply and rapidly performed by reason of the easy and universal horizontal adjustability of the assemblies 39 along the base plate 11 and the firm and reliable magnetic support thereof to the base plate 11 and the universal angular adjustment of the arm 48 relative to the post 46 and the pin 54 relative to the arm 48. The impression A is then filled with a settable fluid mold material such as plaster of pans, a fluid epoxy resin or the like and the vibrator 28 is energized for a time to properly compact and uniformly distribute the molding material and is then deenergized. The molding material is then permitted to harden to form the die B and the pins 54 separated from dowels 40 and the pans 34. A section C of the die B, as shown in FIG. 8, provided with the partially imbedded dowel 40 can be then severed from the die B and employed in the known manner.

In FIG. 7, the improved apparatus 10 is illustrated as applied to the application of another form of dowel. The dowel 57 is highly flexible to minimize the vibration thereof in and relative to the mold material during the vibration of the impression A and is formed of a tapered flexible wire coil which is releasably engaged at its wide end by the pin 54. The apparatus is employed with dowels 57 in the manner described above.

While there have been described and illustrated preferred embodiments of the present invention it is apparent that numerous alterations, omissions and additions may be made without departing from the spirit thereof. For example, although the dowels are illustrated as being tubular, they may be solid and of other configurations and the pin 54 may be accordingly replaced by other elements or chucks for releaseably holding the respective dowels. Further, while a ball joint or joint is illustratively shown and discussed for providing freedom of movement, other means which provide movement to any degree of rotation in one or more planes between the arms, such as swivels, cams, sponges or the like may be used. Also, the base of the dowel support assembly can fully or partially embrace the magnet and may or may not support the vertical column. The surface on which the basis of the dowel support assemblies rest could be magnetized instead of the dowel support base.