with reference now to the drawings , and in particular to fig1 - 6 thereof , the device , as generally designated by the reference numeral 10 , will be described . a preferred embodiment of the present invention , as shown in fig1 a , is a bilayered accessory device 10 simulating the appearance of an assemblage of teeth and gums with a gum portion 12 and tooth portion 14 . when fitted to an individual user and worn over his or her own upper front teeth and gum , accessory device 10 covers the teeth that are most visible when the user smiles . preferably , device 10 is dimensioned to cover at least the six center front teeth ( the upper incisors and canines ); more preferably , at least eight center front teeth . device 10 may be approximately rectilinear ( fig1 b ) which readily adapts to the curvature of the user &# 39 ; s teeth . device 10 as illustrated in fig1 a and 1b is a maxillary or upper dental device ; however , it will be appreciated that the following description is equally applicable to a mandibular dental device that covers the lower front teeth and gums , except such a device would prevent bite closure . in accordance with a preferred embodiment of the present invention , tooth portion 14 of accessory device 10 is shaped to simulate attractive natural teeth ( device 10 is shown worn by a user u in fig2 ). while it is believed that most users prefer a device that resembles natural , unadorned teeth , device 10 may be embellished with fashionable decorations such as simulated gold crowns , gold insets or precious stone insets if desired . alternatively , device 10 may include simulated cavities , fissures , sores and the like . thus , device 10 may be used as a cosmetic or therapeutic accessory to enhance the user &# 39 ; s appearance and self - esteem , as an amusing disguise or theatrical accessory to give the user the appearance of teeth different from his or her own , as an educational tool to teach children the value of good dental hygiene and the consequences of poor hygiene , or as an accessory to illustrate the results of planned dental treatment . before fitting , the bilayered device 10 is an outer labial shell attached to a thin fitting portion of material . the outer labial shell consists of either a thin arched shape or a nearly flat rectilinear shape . the outer labial shell has an approximately smooth inner lingual surface 16 and an outer labial surface 18 ( fig3 a ). the thin fitting portion 30 interfaces the outer labial shell along the inner lingual surface 16 . labial surface 18 preferably has a plurality of indentations 20 that delineate individual “ teeth ” 22 . the gum portion 12 and teeth portion 22 of the labial surface is colored to resemble natural gum tissue and teeth respectively , by incorporating a suitable coloring agent into the material of gum portion 12 and teeth portion 22 . alternately , gum portion 12 and teeth portion 22 may be painted , dyed or colored with some other convenient technique after manufacture of device 10 . after fitting to an individual user , accessory device 10 is a thin , arch shaped preferably no more than approximately 1 - 3 mm thick . the inner surface 16 is at least partly covered by a thin portion 30 of fitting material that forms projections 32 that fit into the spaces between the user &# 39 ; s teeth ( fig3 b ) and , optionally , an inwardly projecting ledge or shelf 34 that helps maintain the position of the device 10 during wear . if there are any natural teeth missing , the user may apply any extra fitting material 30 ( fig6 ) to fill the empty space between the missing teeth to additionally aid in securing the device in position during wear . device 10 is made of any nontoxic , nonirritating , tasteless , odorless material ( or combination of materials ) that has sufficient structural and mechanical integrity to maintain its shape and secure the device in place during normal activities such as speaking , laughing , drinking , and so forth . the materials are chemically stable and easy to clean , and somewhat flexible and resilient to minimize irritation to the user &# 39 ; s mouth and enable the user to take off and put on the device . in addition , the materials does not stick to natural teeth , gums , or most dental work such as fillings , inlays , crowns and bridges , bondings and the like . to permit custom fitting device 10 to an individual user , the preferred material is firm at and below body temperature . the field of dentistry teaches a variety of suitable food or medical grade materials from which one can make the device including polyesters , alkyd resins and acrylic polymers . in the present invention , the bilayered device 10 consists of an outer labial shall and a thin fitting layer 30 . the outer labial shell is made in two layers , a tooth portion 14 and a gum portion 12 . typically , these two layers are of similar materials . the thin fitting layer 30 is a different type of material which possesses good properties for impressioning . the tooth portion 14 and gum portion 12 are each made separately and the two portions are fused together by an adhesive or overlay technique to form the outer labial shell . the fitting layer 30 is attached to the inner surface of the outer labial shell by heating in the oven to form the final bilayered device 10 . the fitting layer 30 has characteristics that permit impressioning of the user &# 39 ; s teeth and gum , and its high tensile strength maintains its shape . pressing the inner fitting layer 30 onto the user &# 39 ; s natural teeth forms projections 32 that aids in securing the device 10 in position . the softening temperature of the outer labial shell is higher than the inner fitting layer 30 . the fitting inner layer 30 cures at temperatures significantly less than the outer labial shell . elongation , hardness and flexibility are important material properties since the device must be stretched or spread out to be placed on or off the user &# 39 ; s natural dentition . all materials should have properties suitable for injection molding . preferably , the outer labial shell materials and fitting portion materials should have elongations when cured ( room temperature ) greater than or equal to approximately 400 % and 600 % respectively . preferably , the fitting portion 30 should be the hardest material and typically the fitting portion 30 has a durometer hardness ranging between approximately 80 to 95 shore a . the material of tooth portion 14 should be the least hardest material and typically the tooth portion 14 has a durometer hardness ranging between approximately 75 - 90 shore a . flexural properties are important in assessing the resistance of materials to bending such that a higher flexural modulus is characteristic of a stiffer material . preferably , the fitting portion material 30 should be stiffer ( more rigid ) and possess a higher flexural modulus than the outer labial shell materials . while materials with the aforementioned properties are preferred , materials having an elongation , hardness and flexural modulus outside these dimensions may also be suitable for the practice of the invention . for example , the bilayered device 10 was shaped and dimensioned for wearing over the user &# 39 ; s upper front teeth . first , the inner fitting portion 30 was die cut in this example , but could have been injection molded . the fitting portion 30 was made using polycaprolactone ( pcl ) which is a biodegradable thermoplastic polymer type plastic . pcl has a low melting - point and low viscosity , and it is easy to process . pcl melts from 120 ° f . to 170 ° f . depending on the environmental conditions . second , the outer labial shell consisting of a tooth portion 14 and a gum 12 portion were injection molded using an overlay method . the tooth portion 14 and the gum portion 12 of the outer labial shell were made of a thermoplastic polyurethane ( tpu ) resin which softened at approximately 203 ° f . other tpu resins with softening points between 196 - 392 ° f . are equally suitable for this application . it was necessary to heat the tooth portion 14 and gum portion 12 to 250 - 270 ° f . in order to fuse the materials together to form the outer labial shell . next , the outer labial shell and fitting portion were attached together by baking them in the oven at 260 ° f . for approximately 5 minutes and 30 seconds . the resulting bilayered device resembling natural teeth was fitted to a user . the fitting material was pcl , the same material used to make the fitting layer 30 . typically the human mouth can withstand temperatures up to 180 ° f ., and the pcl melts and cures below this temperature . a satisfactory fit was achieved , with projections 32 , anchors 24 and a shelf 34 that helped maintain the position of the device 10 during use . device 10 may be manufactured by any suitable technique , including molding , stamping , casting and the like . as noted above , the outer labial shell was injection molded using an overlay method , and the tooth portion 14 and gum portion 12 were both made of tpu . because tooth portion 14 and gum portion 12 were made of similar materials , the overlay injection molding process bonds the two portions . the device is preferably manufactured with gum portion 12 and teeth 14 being made of pigmented materials to resemble natural gums and teeth , respectively . the pigments were mixed into the raw materials before molding . however , gum portions 12 and teeth 14 could be colored with suitable paints or dyes that are nontoxic and chemically stable . an improvement of the present invention over the invention disclosed by albert et . al . in u . s . pat . no . 5 , 951 , 291 is that if the fit is not comfortable , the user can simply place the device in hot water and refit again due to the properties of the pcl material . the previous invention used silicone as the primary filling material which could not be refitted after curing to room temperature . in addition , silicone has undesirable properties such as poor abrasion resistance , tensile strength and poor flex fatigue . in the present invention , there is no silicone , the pcl and tpu materials overcome the disadvantages of silicone . it is known in the art that the range of individual variations in the size of the adult human mouth and teeth is relatively small . for example , the lateral spacing between the rear molars is approximately 2 inches . therefore , an accessory device according to the present invention can be made in a range of sizes to cover the expected range of variations commonly found in the adult human mouth , and if desired , smaller sizes may be made for children . preferably , however , the device is made in a single size that fits substantially all adults , and fitted in a manner to be described below . referring now to fig4 , there is shown a method for fitting device 10 to an individual user . as shown in fig1 a and 1b , device 10 is supplied in the form of a shell bearing the outlines of several front teeth . note that device 10 is shown as an accessory for the user &# 39 ; s upper front teeth ; however , it will be understood that device 10 may readily be shaped and dimensioned for covering the lower front teeth . the device may be supplied in kit form 40 ( fig5 ), with a container 42 , fitting instructions 44 , a device 10 , and envelope 46 that contains the fitting material 30 . the user proceeds to custom - fit device 10 to his or her mouth as follows : 1 . wash hands thoroughly . 2 . determine the preferred placement of device 10 in the mouth . with device in proper position pull down on center of upper lip to determine if device needs trimming to be comfortable . remove device 10 from the mouth . if needed , cut a small notch 36 into gum portion 12 ( fig1 a ). notch 36 accommodates the frenum ( a small web of connective tissue that extends between the gum and the upper lip ) that may otherwise , in some users , interfere with the proper placement of device 10 . device 36 may , of course , be supplied with a pre - cut notch 36 , positioned generally as indicated in fig1 a . 3 . open envelope 46 , and remove the gum colored chip . 4 . melt the gum colored chips of fitting material 30 in very hot water and form into a spaghetti size piece as long as the entire length of the device 10 by rolling the fitting material 30 in the palm of hand . set aside envelope 46 with the remaining fitting material 30 . 5 . dip the top edge of the device 10 into very hot water and apply spaghetti size piece of pink fitting material 30 to top edge of inner lingual surface 16 of device . 6 . submerge entire device 10 in hot water and position in mouth after inner lingual layer 16 is melted . while looking in a mirror , firmly push device 10 straight into position against the upper front teeth and gums , with fitting material 30 on the inside ( i . e ., contacting the natural teeth and gums ). do not bite into fitting material 30 . push inner surface 16 of device 10 ( covered with fitting material 30 ) against the teeth and gums , making sure that the device is properly positioned and hold in place for 2 minutes for cooling . 7 . remove the device 10 by spreading it outward and allow the device to continue to cool for 3 minutes . 8 . trim away any excess fitting material 30 , including any interproximinal points and any other points that impede the natural bite . retain some projections ( i . e ., projections 32 , fig3 b ), since these are necessary to hold device 10 in place during use . 9 . place device back in mouth to check the fit . if the fit is acceptable , device 10 is finished and ready for use . if the fit is uncomfortable , repeat steps 6 - 9 . device 10 is preferably furnished in a size that can readily be fitted to the vast majority of adults and , indeed , to many older children as well . for users with somewhat smaller - than - average jaws , a portion of device 10 with one or more of the “ teeth ” may be cut off so as to help achieve a better fit . alternatively , device 10 can be made in a range of sizes . as noted above , device 10 is made of materials that do not stick to natural teeth or most dental work . however , the device and / or fitting material 30 may mechanically surround or adhere to dental braces , exposed wires of partial dentures , and similar items when softened . when fitting device 10 to an individual who wears braces or other dental appliances with exposed wires , it is preferable to cover and round off the wires with removable wax before placing the device over the teeth . it will be evident to those skilled in the art that device 10 is best used only by those with reasonably good oral health . in use , a fitted accessory device 10 is worn engaging the upper front teeth so that projections 32 fit into the spaces between the user &# 39 ; s natural teeth and shelf 34 ( if present ) is just under the teeth . as best seen in fig3 b , device 10 is approximately semicircular in cross section after fitting . thus , custom fitted projections 32 , missing tooth anchors 24 and shelf 34 hold device 10 in place in the user &# 39 ; s mouth . or the fitted device 10 can be described as having imprints that match the user &# 39 ; s teeth and is held in place by the mechanics of matching surfaces . unlike conventional dental accessories , the natural teeth and gums are not fully covered , so device 10 is comfortable to wear and does not interfere substantially with natural speech or bite closure . also , unlike other conventional dental accessories , neither the device nor the fitting material protrudes into the mouth cavity . the user is able to speak , laugh , open and close his mouth , and drink normally while wearing the device . it will be apparent to those skilled in the art that many changes and substitutions can be made to the preferred embodiment herein described without departing from the spirit and scope of the present invention as defined by the appended claims .
an improved cosmetic accessory device for teeth that simulates the appearance of an assemblage of teeth and gum . the device includes a gum portion and a tooth portion shaped and dimensioned to cover the user &# 39 ; s upper or lower front teeth . the device is made of a nontoxic , nonirritating , tasteless , odorless , resilient , easily cleaned and chemically stable material that does not stick to natural teeth , gums , or most dental work . in use , the device is held in place by custom - fitted inner projections that match the spaces between the user &# 39 ; s own front teeth . optionally , a shelf extending just across the front teeth and extra fitting material placed in spaces where there are missing teeth provides additional security in holding the device in place . the device may be refitted as necessary by simply partially submerging the device in hot water . unlike typical conventional novelty dental devices , the natural teeth and gums are not completely covered and there is no protrusion into the mouth cavity , so the device is comfortable to wear and does not interfere with natural speech or bite closure .