The invention relates to a stabilizer for tooth prostheses according to the preamble of claim 1, an auxiliary device according to claim 13, and a method according to claim 15.
Such stabilizers for tooth prostheses are already known in a plurality of embodiments. These primarily consist of two arms that are swivelingly connected by a joint and pushed apart by spring elements, by means of which arms the upper and lower prosthesis parts are connected to each other on both sides (right and left).
Document DE 195 46 960 C2 teaches of a stabilizer for tooth prostheses in which both of the two stabilizer arms are connected to each other in a spring-loaded manner by means of a joint provided with a torsion spring. Each of the free ends of the arms is screwed to the exterior of the prosthesis part. In so doing, the stabilizers are arranged and dimensioned in such a manner that their joints are located on or after their rearward ends of the prosthesis parts. In this way, although the arms of the stabilizers are arranged in an unchangeable position on the prosthesis parts, they cannot follow the natural movement of the teeth or mandible because the natural swiveling of the human lower jaw occurs at a point farther back in the head.
This is disadvantageous given how complicated repairs are in the instance of wear or breakage of the stabilizer parts, for example the breakage of a spring. Proper repair cannot be quickly and easily effected by the wearer of the prosthesis, but rather by a dental technician only since the screwed connection of the prosthesis arms can be unscrewed only with special tools.
Document EP 1 046 380 A1 teaches of a stabilizer for tooth prostheses that is designed similarly to the previously described stabilizer, wherein the upper arm is designed to be able to elongate telescopically and its outer end is bolted to the prosthesis part, while the lower arm, provided on its outer end with a sliding block, is provided in a longitudinally movable manner by means of a guide groove in the lower prosthesis part.
Greater freedom of movement of the stabilizers and thus of the upper and lower prosthesis parts toward each other is indeed achieved herewith, which makes it possible to carry out natural movement more easily. However, this tooth stabilizer consists of a relatively great number of individual parts, presenting an increased susceptibility to failure. Moreover, the arms are here too movably arranged on the exterior sides of the prosthesis parts, meaning that movement may cause a disturbing sensation or even pinching of the skin on the inside of the cheek. Furthermore, the entirety of the stabilizers is visible on the outside of the prosthesis, which some wearers of prostheses consider aesthetically displeasing and unacceptable.
Finally, document WO 2007/016753 teaches of a stabilizer for tooth prostheses that is composed of only one two-armed torsion spring, wherein the stabilizer arms are simultaneously the long, curved ends of the torsion spring that are movably arranged so as to telescope and axially glide in cylindrical guides of the prosthesis parts. Owing to the floating movability in the longitudinal guides, the arms can now glide, if necessary, so that each half of the prosthetic can move naturally toward the other half. The stabilizer parts, or at least the arms, are also largely protected from direct contact with aggressive agents. Moreover, the overall wearing comfort is substantially increased since the movable arms of the stabilizer parts are no longer in direct contact with the inside of the cheeks of the wearer of the prosthesis. Because of the possibility of an optimal curved design or guiding of the stabilizer arms in the correspondingly designed guides, e.g. in the lower prosthesis half corresponding to a curve of Spee (curve that is modeled on the shape of the profile form of the row of teeth), while the upper arm or the guide in the upper prosthesis half likewise has an arc radius of special design, it is possible when the mouth is opened or closed or when the chin is moved up and down that the stabilizer arms optimally glide in the guides without impeded movement or friction that can be perceived as disturbing.
Disadvantageous, however, is that the smooth stabilizer arms are located practically loosely movably in the guide bore so that upon removal of the prosthesis parts the arms slip out of the guides, resulting in the risk of the stabilizers dropping out and not or (in particular for hygienic reasons) no longer being able to be inserted without prior re-assembly. Moreover, saliva and food particles as well can enter the relatively long guides, the cleaning of these relatively narrow blind hole guide bores being either not possible or only possible with great difficulty. In order to avoid this, the stabilizers are, from their spring joint to the guide bores, coated in plastic or are embedded in plastic bushes that, however, tear easily and additionally limit the flexibility of the centric coil spring part.
The object of the invention is thus to provide a stabilizer for tooth prostheses of the abovementioned type, which stabilizer is easily and securely designed, assembled, fitted or refitted by the dental technician, or with which fitting or refitting by the dental technician as well as wearing comfort and hygiene (for the wearer) is ensured, which stabilizer is also easily self-inserted or self-exchanged and does not fall apart by itself. A method shall furthermore be stated for ensuring simple and economical positioning of the embedded guides by the use of a simple and easy-to-handle auxiliary device.
This object is solved by a stabilizer for tooth prostheses with the characterizing features of claim 1. Advantageous developments are characterized in the corresponding appended subclaims.
According thereto, the guides for the stabilizer arms are frontally closed (to prevent falling apart) from their outer insertion ends to a narrow narrowing, for example a narrow insertion slot in the style of mailbox slot (but also a latch, a spring-loaded pin, an elastic membrane or generally known locking elements). The ends of the spring ends are furthermore outfitted with extensions, for example flat extensions in the style of an eyelet, loop, or elbow (potentially with inserted flat part of a knob) or of a ball or the like, shaped and dimensioned in such a manner that they can be inserted, flatly or with little latch resistance, through the narrowing or through the insertion slot of the guides.
It is therefore advantageous if the narrowings or the insertion slots of the guides and the flat extensions or eyelets of the spring arms are designed or arranged in such a manner that in the integral operational position of the stabilizers, the extensions/eyelets or eyelet ends are arranged approximately perpendicular (preferably about 90°±20°) to the longitudinal extension of the narrowings or the insertion slots or the like. It is significant that through the particular arrangement of the insertion slots, the stabilizer arms do not slip out of the prosthesis parts in an unintended manner, in particular when the prosthesis is not in the mouth. In order to return or insert the stabilizers into the respective guides of the prosthesis parts, the stabilizers or their arms must be pushed through the insertion slot in the position perpendicular to the operational position in order thereafter to be swiveled by approximately 90° so as to be brought into their operational position.
It goes without saying that other known structural solutions for limiting the removal path of the spring arms can be used, such as, for example, a ball end of the spring arm and a slit elastic membrane, or an outward-pointing hook (open or closed) on the spring arm end and an exterior step interacting therewith on the insertion end of the guide slit.
This provides the great advantage that individual wearers of the prosthesis can personally easily and simply exchange or even completely remove the stabilizers of their prosthesis as needed without tools, in so far as the prosthesis is at least disturbing the wearer or is broken, because the prostheses can routinely be exchanged.
The optimal handling of the stabilizer is particularly important during wearing if, for example, a foreign body gets trapped and wedged in the space between the spring and the dental prosthesis. The prosthesis can then be removed by the wearer subsequent to which, by turning the spring barrel that acts as a type of handhold, the spring arms can be screwed out of the prosthesis or swung horizontally and removed. The prosthesis can thereafter be immediately used again as a customary dental prosthesis without fasteners or spring-loaded stabilizers, and all with minimal handholds and movements and no tools.
The guides for the stabilizer arms can be provided as simple, correspondingly long bores in the body of the prosthesis, positioned from the rear side of the prosthesis, the opening in this instance then being designed as closed with a corresponding insertion slot on the removal or insertion side formed by a small panel or similar or by the appropriate application of sundry materials or a closing element such as a latch in order to provide an operational insertion slot in the style of a mailbox slot or a similar narrowing. The positioning, in particular the subsequent positioning of correspondingly curved guide bores is, however, very complex to carry out. The insertion slot, as previously described, must thereafter also be provided with an appropriate material application also as an additional slotted small panel. It is therefore particularly advantageous if the guides are provided as tubular guide bushes that are embedded in the prosthesis material in such a manner that the faces of their external insertion ends terminate in the rear side of the individual prosthesis ends, preferably flush thereto or therewith. In each instance, a guide bush is inserted into or embedded in correspondingly large curved recesses as guides in the support material of the prosthesis part, which guide bushes have a size and shape designed to correspond with the desired guide or position of the stabilizer arm. This makes it possible to dispense with all relatively complex labor, these guide bushes already being provided with their one open end closed on the required insertion slot (narrowing).
It must also be recognized that these guide bushes are longitudinally, that is to say in the direction of the row of teeth, insertable into a correspondingly positioned bore. However, there is the additional simplifying possibility of inserting these guide bushes into laterally positioned tubular recesses and thereafter refilling or filling the remaining intermediate spaces with corresponding material in such a manner that this action remains as good as invisible. Since these bent recesses or grooves are thus so easily laterally positioned from the outside, for example by milling or grinding, the retroactive positioning of the guide bushes is quickly and neatly possible with no further problems.
The eyelets or hooks of the spring arms of the stabilizer can be bent in the same plane as the spring arm, that is to say spring arms and their eyelets are positioned substantially in the same plane. That means, in turn, that in the integrated state in which the entirety of the stabilizer comes to rest in a vertical plane, the respective eyelets likewise are situated in this same vertical plane. This also means that the insertion slots on the guide bushes, which are known to be provided perpendicular to the direction of the eyelets, are also provided in the corresponding horizontal direction. After the ventilation openings or the ventilation tubes on the guide bushes protrude horizontally in the integrated state, the insertion slot is to be arranged or provided in that same direction, which also implies a simplification in their design. In this way, the insertion slot also simultaneously acts as a sliding bearing during lateral movement of the dental prosthesis.
It is advantageous if an approximately bead-shaped pellet (ball, spherical cap, cylinder, oval) is respectively securely fixed near (e.g. at a distance of 2 to 3 mm) the eyelets on the spring arms. The pellets composed of glass, plastic or stainless steel are marginally thicker than the width of the mailbox slot, preferably 0.2 to 0.3 mm. They form a latch in such a manner that the slot (or the pellet or both) elastically deforms upon removal. This causes the spring arms not to glide out should the dental prosthesis parts flap apart completely leading to the possible tipping of the spring arms in such a manner that the eyelets are directed parallel to the insertion slots, but rather the spring arms remain inside with the pellet on the slot. With the application of light pressure, the pellet can be pulled through the slot subsequent to which the entire spring arm can be pulled out. Likewise with the application of light pressure, the spring arm can thereafter be reinserted anew.
Manufacturing is simplified if the eyelets together with the beads associated therewith are designed as a separate unit that is slid or firmly clamped onto the straight (simply truncated) arm ends. When closed eyelets or partially closed eyelets/hooks are on the ends of the spring arms, it can be provided to prevent falling out that these eyelets/hooks are designed as minimally wider than the length of insertion slots and can elastically be pressed together in the transverse direction thereof. The removal or insertion of the arms through the insertion slots thus occurs under light tension or pressure, elastically snapping into or out of place.
It is particularly advantageous if the guide bushes are plastic tubes whose interiors (in the integrated state) present at least one, preferably three, holes or radially lateral openings arranged in the longitudinal direction of the tube, which holes are connected to the exterior side of the prosthesis parts, through which connection cleaning and ventilation holes are formed. Thus, saliva or even food particles having entered the guide bores can exit again through the lateral ventilation holes. Moreover, in the care of the dental prosthesis in its removed state, the guide bores can be properly rinsed so that no food particles or saliva remains in the guides for a long period of time and decays, which can lead to halitosis, inter alia.
Advantageously, the ventilation holes can also be managed on the inside of the mouth (tongue side) so that a suction effect from the inside of the mouth, blowing through, spraying through or with brush and rinsing allows for a more effective cleaning process.
In that the guide bush can already be designed in the shape of a plastic tube, it is now possible to provide the radial openings by positioning corresponding plastic tubes. Of course subsequent to the positioning of the guide bushes it would be possible to place corresponding tubes in the radial direction for the ventilation holes. It would, however, make more sense and be considerably easier to combine into one integrally formed structure the respective plastic tubes, that is to say those of the guide bush and those of the ventilation holes, thereby forming a comb-shaped or bilaterally toothed guide rack. This makes possible a relatively fast and simple as well as secure refitting of dental prostheses with stabilizers.
It is advantageous to increase wearing comfort, prevent possible problems from arising owing to direct contact with the metal joint of the stabilizer, and to prevent or substantially reduce in particular the possibility of food particles becoming stuck or accumulating in the joint windings of the torsion springs of the stabilizers if the coil spring part, that is to say the joint part, is axially held or enveloped by a plastic spool. This plastic spool can substantially consist of two flange parts that are in the style of a snap fastener, can be pressed together axially, and can be locked in place or bonded. Accordingly, the spring flange parts closely envelop the exterior or front face of the spring, and the spiral windings of the stabilizer spring are axially held together at a predetermined measurement. Through the flat, slightly bowed, rounded head section of such a plastic spool, and through contact with the cheek, the position is stabilized and the wearing comfort is substantially increased. The surface and curvature of the plastic spool correspond approximately to the lateral surfaces of a molar. During assembly, the plastic spool additionally serves as a relatively secure and comfortable handhold.
The design according to the invention of the guide bush in the style of guide rack also has the advantage that it is very readily, simply, and securely handleable upon its insertion facilitated by means of a corresponding auxiliary device (according to claim 12).
According to the invention, an auxiliary device is moreover provided with which the guide rack(s) are held or fixed by their lateral rinsing or ventilation tubes and are laterally inserted into the slot in the prosthesis part and held until embedding with additional material has been securely effected. This auxiliary device advantageously consists substantially of a holding part or handhold on whose front end, for example on a flange part arranged perpendicularly thereon, two rows of retaining gudgeons protrude perpendicular to the flange part while simultaneously being provided in a parallel arrangement to each other, while having the same number and same distance from one another as the rinsing tubes (one-sided) on the guide tubes. The gudgeons have substantially the same exterior measurements as the interior measurements of the rinsing holes and are also adjusted thereto with regard to length. By means of its rinsing hole tubes, the guide rack is thus attached on the gudgeons of the auxiliary device and can be easily positioned in the appropriate position in the prepared channel in the prosthesis part by a dental technician using the abovementioned auxiliary device.
It is furthermore advantageous that both guide bushes or the guide bushes of both prosthesis parts, that is to say the upper and lower parts, of one prosthesis side can be positioned at the same time. Two rows of retaining gudgeons having corresponding spacing and a curved arrangement are provided for this purpose. For those individuals who are larger and accordingly have relatively higher sets of teeth, a third row of retaining gudgeons is arranged parallel to and correspondingly externally distanced from the first or from the second row of retaining gudgeons.
A subtask of the invention is also solved by/through a method (according to claim 14) for inserting/embedding into the prosthesis parts the guide bushes or guide racks or the spring arms of the stabilizer.
Accordingly, the prosthesis parts to be equipped with the stabilizers according to the invention are fastened to each other, resting one atop the other in a position corresponding to that of the closed mouth, subsequent to which lateral, tubular recesses are introduced having into the rearward zone of both prosthesis parts, which recesses correspond to the intended progression of the stabilizer arms or the shape of the guide racks to be inserted, the corresponding depth and length of said recesses being achieved through grinding and/or milling. Of course, these tubular recesses or grooves for the guide bushes can each be inserted separately into the prosthesis parts prior to fastening the prosthesis parts to each other, after which insertion the prosthesis parts can be fastened to each other in the desired position.
In a further step, the previously described auxiliary device, which is equipped with two rows of gudgeons, is fitted with a guide rack above each row of gudgeons, upon which guide rack are then attached the rinsing hole tubes, after which said guide rack is then laterally inserted in a substantially horizontal sliding motion into the provided grooves of the prosthesis parts. By means of the handhold of the holding device, the entire holding construction, with both guide racks optimally positioned, can then be held and fixed until the remaining cavities of the grooves and the exteriors of the guide racks have been filled with appropriate material and said material has solidified. It must be noted at the same time that the insertion narrowings (mailbox slots) are each closed off against soiling, for example by one of the wedges that are inserted thereinto and are part of the assembly device. After sufficient hardening of the plastic that has been poured in, the auxiliary device is removed and the protruding ends of the rinsing hole tubes are cut off so as to be flush with the exterior of the prosthesis. A smoothing of the surfaces and the edges of the guide tubes and naturally also of the areas with the slot-shaped insertion holes is then finally conducted through polishing or repolishing. After completion of this work, only the rinsing holes and the insertion slots in the back are laterally visible from the outside. Subsequent to completion or the conclusion of positioning the guide parts on both prosthesis sides in the two prosthesis halves, both stabilizers can then quickly and easily be inserted through several movements, thereby making the dental prosthesis ready for use.
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| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2008 029 086.6 | Jun 2008 | DE | national |