Description

JIG FOR FABRICATING DENTAL MODEL

Technical Field

[1] The present invention relates to a jig for fabricating a dental model. More specifically, the present invention relates to a jig for fabricating a dental model, which enables, when it is intended to fabricated a prosthesis for a damaged tooth, fabrication of a dental model from an impression mold of teeth of a patient, separating only a model of a damaged tooth from the dental model fabricated thus, and securing a renewal tooth of the damaged tooth to a required position. Background Art

[2] In general, when it is intended to fabricated prosthesis for a damaged tooth, the following steps are required.

[3] At first, the damaged tooth is treated as well as trimmed for fabrication of the prosthesis at a dentist's. Once the damaged tooth is trimmed, an impression material tray having an impression material stuffed therein is placed in a mouth of the patient to form an impression mold which has in intaglio of the damaged tooth and an antagonist tooth thereof. As the impression material, a material selected from silicone rubber, polysulphides rubber, agar, alginate can be used.

[4] The impression mold obtained through an impression step is provided to a dental technician, and the dental technician forms a dental model by filling a solidifying material, such as dental cement, gypsum, casting stone, or so on in the impression mold, to form the dental model. Once the dental model is finished, a fixing pin is inserted and secured to each of teeth of the dental model from an underside thereof, and a base portion is formed on a bottom of the dental model to cover the fixing pins. Then, only a model of the damaged tooth is cut-off to separate from the dental model. Once the model of the damaged tooth is obtained, a wax-up step is taken to form a wax pattern model of a cone shape. If formation of the wax pattern model is finished, the wax pattern model is invested with a semisolid refractory investment, such as gypsum, or a silicon bonded investment filled in an electric furnace. The semisolid refractory investment or the silicon bonded investment is hardened and then heated slowly up to a preset temperature to burn down the wax pattern model to form a mold. If the mold is obtained thus, a molten metal of a dental casting alloy, such as gold or silver, is fed to a casting space in the mold by using a centrifugal casting machine, to finish formation of the prosthesis.

[5] Of above steps, the steps for inserting the fixing pins in the dental model, and forming the base portion will be reviewed in detail.

[6] At first, once fabrication of the dental model is finished, as a preparation of inserting the fixing pins in the bottom surface of the dental model, the bottom surface is grinded to make the bottom surface flat. In the grinding, the dental model is wet with water for preventing much dust from flying in the grinding. Upon finishing the grinding, the dental model is dried for 30 minutes to one hour.

[7] Upon finishing the flattening of the dental model, a fixing pin inserting hole and a recess are formed in the bottom surface of the dental model with a drill for each of the teeth.

[8] Then, the bottom surface of the dental model is washed with water to remove chips from the recess and the dental model is dried for 30 minutes to one hour. If the chips are left on the bottom surface of the dental model, a fine gap is formed between the dental model and a base to be formed later, even partially, to make a position of the dental model poor, impairing accuracy of the prosthesis which is a final product such that the patient feels a sense of foreign matter on the prosthesis.

[9] Upon finishing formation of the inserting holes, an adhesive is applied to the fixing pin and the fixing pin is inserted in, and secured to each of the inserting holes.

[10] If the fixing pins are fixedly secured to the bottom of the dental model as a preset time period passed, a parting agent is applied to the bottom of the dental model, and waits until the parting agent is hardened.

[11] If the parting agent is hardened fully, a primary base is formed on the bottom of the dental model to cover the fixing pins. Formation of the primary base is finished through a drying process of about 30 minutes after applying the solidifying material, such as the dental cement, gypsum, and casting stone, to lower sides of the fixing pins. The parting agent enables the primary base and the dental model to put together or separate from each other.

[12] The fixing pins and the recess formed in the bottom of the dental model have an important function of guiding the damaged tooth model to be always placed at the same position without movement from the primary base, enabling to fabricate an accurate prosthesis.

[13] Upon finishing formation of the primary base, a secondary base is formed, which covers an underside of the primary base fully for protecting the primary base. The secondary base is formed by filling the solidifying material, such as dental cement, gypsum, casting stone, and so on in a mold provided in advance, investing a lower portion of the primary base in an upper portion of the solidifying material, and having a drying step of in a range of one hour.

[14]

Disclosure of Invention

Technical Problem

[15] However, the prosthesis fabricated by above steps has problems in that an accuracy of the prosthesis is poor significantly due to accumulation of shrinking and expansion errors come from absorption and drying of the solidifying material of the dental model and the base portion in view of a nature of the material as the dental model and the base portion repeat many times of water absorption and drying in the steps of fixing the fixing pins to the dental model, and quickness is poor significantly as long time periods are taken until the dental model and the base portion are dried.

[16] Furthermore, the essential complicate intermediate steps, such as grinding of the bottom of the dental model, formation of the recess, application of the parting agent, formation of the primary and secondary bases, impair productivity, significantly.

Technical Solution

[17] To solve the problems, an object of the present invention is to provide a jig for fabrication of a dental model which enables quick fabrication of an accurate dental model by a simple process.

[18] To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a jig for fabricating a dental model includes a supporting member having a base plate for placing an impression material tray thereon having an impression mold seated thereon, a vertical plate extended in up/down directions from a front edge of the base plate, and slots formed on the same line in an upper edge and a lower edge of the vertical plate and, a propping member to be removably secured either to an upper surface or a bottom surface of the base plate of the supporting member by means of the slots respectively for fixedly securing fixing pins 240 which fix the dental model.

Advantageous Effects

[19] The present invention has following advantageous effects.

[20] The jig for fabricating a dental model of the present invention improves accuracy and quickness of fabrication of the dental model significantly because no water absorption and drying steps are required at all in a process of fabrication of the dental model and fixing the fixing pins to the dental model, leading to cause no shrinkage and expansion errors and save drying time periods.

[21] Along with this, the jig for fabricating a dental model of the present invention can improve productivity in fabrication of the dental model significantly and shorten a fabrication time period of the dental model significantly because all of the complicate intermediate steps, such as a dental model bottom grinding → drying → recess forming → washing → drying → application of a parting agent → drying the parting agent → forming a primary base → drying → forming a secondary base, and so on which are

required to carry out without fail in the related art, can be omitted owing to the molding of the dental model on a base surface of a propping member in a state the fixing pins are secured to the base surface of the propping member. Brief Description of the Drawings

[22] The accompanying drawings, which are included to provide further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiments of the disclosure and together with the description serve to explain the principle of the disclosure.

[23] In the drawings:

[24] FIG. 1 illustrates a perspective view of a supporting member in a jig for fabricating a dental model in accordance with a preferred embodiment of the present invention.

[25] FIG. 2 illustrates a bottom perspective view of a supporting member in a jig for fabricating a dental model in accordance with a preferred embodiment of the present invention.

[26] FIG. 3 illustrates a perspective view of a propping member in a jig for fabricating a dental model in accordance with a preferred embodiment of the present invention.

[27] FIG. 4 illustrates a bottom perspective view of a propping member in a jig for fabricating a dental model in accordance with a preferred embodiment of the present invention.

[28] FIG. 5 illustrates an exploded perspective view of a jig for fabricating a dental model in accordance with a preferred embodiment of the present invention.

[29] FIG. 6 illustrates a perspective view of a supporting member having a propping member placed in an underside thereof in accordance with a preferred embodiment of the present invention.

[30] FIG. 7 illustrates a side view showing a state in which inserting holes are made in a supporting member by using a drilling machine in accordance with a preferred embodiment of the present invention.

[31] FIG. 8 illustrates a bottom view of a supporting member showing a state in which fixing pins are fixedly secured to a supporting member in accordance with a preferred embodiment of the present invention.

[32] FIG. 9 illustrates a perspective view showing a state in which a dental model is being formed with an impression material tray filled with a solidifying material placed between a supporting member and a propping member of the present invention.

[33] FIG. 10 illustrates a perspective view showing a dental model fabricated by using a jig for fabricating a dental model of the present invention and a damaged tooth model separated from the dental model. Best Mode for Carrying Out the Invention

[34] Reference will now be made in detail to the specific embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Words and terms used in the specification and claims of the present invention should be interpreted in meanings and concepts meeting technical aspects of the present invention in a principle that the inventor can define the concepts of the words and the terms appropriately for describing the inventor's invention in the best way. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts, and for clarity sake, only different parts different will be described for avoiding duplicated description.

[35] Referring to FIGS. 1 to 5, the jig for fabricating a dental model includes a supporting member 100 for placing an impression material tray T thereon having an impression mold A seated thereon, and a propping member 200 for joining with fixing pins 240(see fig 8) which are removably placed in an upper surface 110a or a bottom surface 110b of a base plate of the supporting member 100 for fixedly securing the dental model.

[36] The supporting member 100 includes a base plate 110 for placing an impression material tray T thereon having an impression mold A seated thereon, a vertical plate

120 extended in up/down directions from a front edge of the base plate 110, and slots

121 and 122 formed on the same line in an upper edge and a lower edge of the vertical plate 120. The slots 121 and 122 are vertical, each with an opened end for slidably placing a propping member 200 in a vertical direction therein. The propping member 200 is removably secured to the upper surface 110a or the bottom surface 110b of the base plate of the supporting member 100 by means of the slot 121 or 122.

[37] There may be a guide wall 130 formed further along a periphery of the base plate extended downward from of bottom surface 110b of the base plate in conformity with a periphery of the propping member 200 for guiding a position of the propping member 200 to be placed on the bottom surface 110b of the base plate. In this case, the propping member 200 placed on the bottom surface 110b of the base plate of the supporting member 100 is in a state received in a space the guide wall 130 and the vertical plate 120 form.

[38] In the meantime, it is preferable that the propping member 200 has a periphery identical to the periphery of the impression material tray T in size and shape, for making easy alignment of the propping member 200 with the impression material tray T with reference to the peripheries when the propping member 200 is placed on the impression material tray T such that the inserting holes 230 can be made accurately in the propping member 200 for securing the fixing pins 240 therein.

[39] The propping member 200 has the dental model fixed thereto. The dental model is formed by applying a pressure to the propping member 200 placed on the impression

material tray T having the solidifying material filled therein. In this instance, the dental model molded thus is in a state stuck to the propping member 200, and, in this instance, the propping member 200 serves as a base of the dental model that supports an underside of the dental model, horizontally.

[40] For this, the propping member 200 has a base surface 210 with a horizontal peripheral surface 220 elevated from the base surface 210 in conformity with a shape of the teeth for supporting an underside of the dental model formed thus, horizontally. Then, the inserting holes 230 are formed in the horizontal peripheral surface 220, and the fixing pins 240 are inserted in, and secured to, the inserting holes 230, respectively (See FIG. 8).

[41] In the meantime, the base surface 210 of the propping member 200 has a T-piece 250 formed thereon for placing the T-piece in the slot 121 or 122 in the supporting member 100. The T-piece 250 is formed at a center of a front end of the base surface 210 of the propping member 200 so that the T-piece 250 is positioned on the same line with the slots 121 and 122 of the supporting member 100. The T-piece 250 includes a stem portion 251 to be placed in the slot 121 or 122 in the supporting member 100 and a wing portion 252 extended from an end of the stem portion 251 in opposite directions for preventing the stem portion 251 from falling off the slot 121 or 122 of the supporting member 100.

[42] It is preferable that the propping member 200 has a supporting projection 260 formed on an underside for maintaining a horizontal position of the propping member 200 placed on an underside of the base plate 110 of the supporting member 100.

[43] A process will be described for fabricating a dental model by using the jig for fabricating a dental model of the present invention and obtaining a damaged tooth model.

[44] Referring to FIG. 5, the impression material tray T having the impression mold A obtained by an impression step seated thereon is placed on the base plate 110 of the supporting member 100.

[45] In this instance, in order to prevent the impression material tray T from shaking, a sticky solid substance (not shown) may be placed on the base plate 110 of the supporting member 100, additionally. The solid substance may be clay which is available easily from surroundings. Accordingly, when the worker applies an appropriate pressure to the impression material tray T placed on the solid substance, a lower portion of the impression material tray T is surrounded by the solid substance such that the impression material tray T is securely seated without shaking.

[46] Once the impression material tray T is placed on the base plate 110 of the supporting member 100, the propping member 200 is placed on the base plate 110 of the supporting member 100. In this instance, the base surface 210 of the propping member 200 is made to face the impression material tray T, and T-piece 250 of the propping

member 200 is placed in the slot 121 in the vertical plate 120 and slid downward to join the propping member 200 with the supporting member 100. As a result of this, the propping member 200 is stacked on an upper side of the impression material tray T, when the worker is required to align the peripheries of the impression material tray T and the supporting member 100, such that teeth portions of the impression material tray T and the horizontal peripheral surface 220 of the supporting member 100 are positioned on the same line, for inserting the fixing pins in, and securing the fixing pins to, the dental model through the horizontal peripheral surface 220 accurately in a later step of placing the fixing pins 240.

[47] Referring to FIG. 6, if the peripheries of the impression material tray T and the propping member 200 are aligned, the propping member 200 is separated from the supporting member 100, and the propping member 200 is placed on the bottom surface 110b of the base plate of the supporting member 100.

[48] In this instance, the base surface 210 of the propping member 200 is made to face down, and the T-piece 250 of the propping member 200 is placed in the slot 122 in the vertical plate 120 extended downward toward the bottom surface 110b of the base plate of the supporting member 100 and slid upward to join the propping member 200 with the supporting member 100.

[49] In a case the guide wall 130 is formed at the bottom surface 110b of the base plate of the supporting member 100 additionally, the propping member 200, surrounded by the guide wall 130 and the vertical plate 120, can always maintain an accurate secure position.

[50] In a case the supporting projection 260 is formed on the underside of the base surface

210 of the propping member 200, the propping member 200 placed on the underside of the base plate 110 of the supporting member 100 can maintain a horizontal state.

[51] Referring to FIG. 7, if the propping member 200 is seated on the bottom surface

110b of the base plate, the supporting member 100 is placed on a drilling machine such that the propping member 200 faces down, and the inserting holes 230 are formed in the propping member 200 for each of teeth.

[52] In this instance, the fixing pin inserting hole 230 is made with reference to a center of each of teeth formed in intaglio in the impression mold A exposed from an upper portion thereof. In this instance, since the peripheries of the impression material tray T and the supporting member 200 are aligned already in a prior step, all the fixing pin inserting holes 230 made thus are formed in the horizontal peripheral surface 220 of the propping member 200.

[53] Referring to FIG. 8, if making the fixing pin inserting hole 230 is finished, the fixing pin 240 is inserted in each of the inserting holes 230 such that a top end of the fixing pin 240 is projected beyond the horizontal peripheral surface 220 of the propping

member 200.

[54] In the meantime, it is preferable that two rows of the fixing pin inserting holes 230 are made for each of the teeth to enhance fastening force so that shaking of the dental model is prevented, positively.

[55] If all the fixing pins 240 are inserted in the propping member 200, as shown in FIG.

9, the propping member 200 is separated from the supporting member 100, and the solidifying material B is filled in the impression mold A seated on the impression material tray T placed on the supporting member 100. Then, the propping member 200 is turned upside down such that the underside of the base surface 210 of the propping member 200 faces up, the propping member 200 is placed on the supporting member 100 again to make the propping member 200 and the impression material tray T to form a stack in up/down directions, and the propping member 200 is pressed down toward the impression material tray T.

[56] In this instance, in order to prevent a void from forming between the propping member 200 and the impression material tray T, it is preferable that the propping member 200 and the impression material tray T are brought into stacking in a state the solidifying material B is applied to the base surface 210 of the propping member 200, adequately.

[57] Then, referring to FIG. 10, after waiting for about an hour for drying, the propping member 200 is separated from the supporting member 100, to obtain a dental model 300 having fabrication thereof finished fixed to the horizontal peripheral surface 220 of the propping member 200.

[58] If the dental model 300 is obtained thus, the dental model and the horizontal peripheral surface 220 of the propping member 200 are cut-off with a cutter 400, to obtain the damaged tooth model C. In this instance, since the base surface 210 of the propping member 200 is positioned lower than the horizontal peripheral surface 220, permitting to secure a certain height from a bottom of the dental model 300, the cutting with the cutter 400 is very easy and safe.

[59] In the meantime, if the propping member 200 and the supporting member 100 are formed of a transparent material, the work can be carried out very easily while checking lower side states of the propping member 200 and the supporting member 100.

[60] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

[61]