Abstract:
An elastomeric adapted to apply constant pressure between orthodontic appliances is formed from silicone. The elastomeric comprises various shapes and configurations. The elastomeric is preferably formed from TUFEL® II 94706, LIM® 6040, or equivalent materials.

Description:
TECHNICAL FIELD  
       [0001]     This invention relates generally to orthodontics, and more particularly to the use of silicone elastomerics in the practice of orthodontia.  
       BACKGROUND AND SUMMARY OF THE INVENTION  
       [0002]     For over fifty years the orthodontics profession has sought improved techniques for moving teeth to correct sagittal relations or occusal disharmonies. Head gears, heavy continuous forces applied by rubber bands, coil springs, magnets, etc. have been tried and are still relied on in cases requiring massive movements of groups or segments of the dentitions.  
         [0003]     Latex rubber bands have been by far the most common source of gentle forces used to move one sector of dentition as it relates to another sector. Changing the relationships of teeth preferably employs a constant force. Rubber bands show a rapid deterioration of force in the human mouth. As is said by dentists, “The human mouth is a strange laboratory.” Within hours, latex elastics lose much of their strength and become useless. Frequent changing is required. Patient cooperation to overcome this need is a real problem.  
         [0004]     Eurathane modules, shaped as small rings, are currently the product of choice for holding metal archwires in place on attachments, such as brackets. Orthodontic brackets, bonded to the enamel surface of various teeth, act as handles for applying forces to individual teeth. Eurathane has been shown by numerous tests to have a short effective life in orthodontic applications. According to numerous studies eurathane absorbs saliva in the oral cavity, rapidly swelling and losing over 40% of its original strength or elasticity in a period of forty eight hours. By the time a patient returns to the orthodontic practitioner for replacements, usually every four weeks, the eurathane is as limp and useless as pasta.  
         [0005]     Chains of small eurathane modules are used to close spaces occurring between various teeth. These too, lose over half their effectiveness in three or four days. Discoloration is an esthetic problem as well.  
         [0006]     The present invention comprises improvements in the art and science of orthodontia which overcome the foregoing and other problems which have long since characterized the prior art. In accordance with the broader aspects of the invention, elastomerics intended for use in the practice of orthodontia are formed from silicone. Under the conditions prevalent in the oral cavity silicone compounds do not discolor, do not take on moisture, and retain most of their strength and elasticity over a period exceeding six weeks. Patient cooperation is no longer a problem, as no change is required in the application of the desired continuous forces needed to achieve the movement of selected dental units. Additionally elastomerics comprising the present invention hold archwires in place in slots provided in brackets attached to the dental units. Continuous forces, as preferred, are thereby applied in the desired directions, either moving teeth via brackets along the metal archwires or alternatively holding the archwire firmly in the slot of the bracket which is attached to the individual tooth.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     A more complete understanding of the present invention may be had by reference to the following Detailed Description when taken in connection with the accompanying Drawings, wherein:  
         [0008]      FIG. 1  is a perspective view illustrating a first embodiment of the invention;  
         [0009]      FIG. 2  is an illustration of the use of the present invention in the practice of orthodontia;  
         [0010]      FIG. 3  is a top view illustrating a second embodiment of the invention;  
         [0011]      FIG. 4  is a perspective view illustrating a third embodiment of the invention;  
         [0012]      FIG. 5  is a perspective view illustrating a fourth embodiment of the invention; and  
         [0013]      FIG. 6  is an illustration of a fifth embodiment of the invention.  
     
    
     DETAILED DESCRIPTION  
       [0014]     Referring now to the Drawings and particularly to  FIG. 1  thereof, there is shown a power bar  10  comprising a first embodiment of the invention. In accordance with the invention, the power bar  10  is injection molded from silicone compounds. For example, the power bar  10  may be formed from a silicone material selected from the group consisting of TUFEL® II 94706 and LIM® 6040. The power bar  10  may also be formed from two or more compounds of silicone. The compounds are in liquid forms, at controlled temperatures. As the liquids meet in the designed configuration of the mold, the resulting composition creates a solid structure identical to the design of the mold.  
         [0015]     In accordance with the invention the cross sectional thickness of the power bar  10  at location A is the same as the cross sectional thickness of the power bar  10  at location B. In this manner the force applied by the power bar  10  is evenly distributed along the entire length thereof.  
         [0016]     The durometer or elasticity of the power bar  10  can be increased or decreased by varying the composition thereof. Color additives may be included in the material utilized in the manufacturer of the power bar  10  thereby distinguishing power bars having various durometers or elasticities by color variations.  
         [0017]     Pictured in  FIG. 2  is a very useful embodiment of the invention, a continuous chain. Edgewise brackets, the most commonly used attachment that is bonded to the facial surface of the teeth provide an upper and lower wing or wings. Under this wing a steel ligature or a bracket encircling module is placed to hold the archwire in place. By replacing the module or ligature with modules forming a chain, a space closing action results. Since the urethane chains commonly used for this purpose lose their strength, usually in forty eight to seventy two hours, the injection molded silicone chain comprising the present invention is vastly superior. The silicone chain, shown in tests to exhibit a strong hysteresis, does not require replacement every few days to be effective. Doctor appointments requiring chain replacements can be spaced at four to eight week intervals, as little or no swelling or loss of strength occurs when silicone compounds are placed in the mouth.  
         [0018]     When stretched from tooth to tooth, a continuous closing action is provided. The same action can be used to move single teeth along the archwire that rests in the slots of the brackets attached to the involved teeth.  
         [0019]     Referring to  FIG. 3  the present invention may also take the form of a chain  20  comprised in a plurality of rings  22  which are interconnected by rods  24 . Prior to utilization, the rings  22  are separated from the rods  24  by cutting along lines  26 .  
         [0020]     Utilization of the rings  22  of the chain  20  in orthodontia is substantially identical to the utilization of the power bar  10  as illustrated in  FIG. 2  and described hereinabove in conjunction therewith. As will be indicated by those skilled in the art, the rings  22  can also be used to ligate orthodontic brackets to orthodontic archwires. The cross sectional dimension C of the rings  22  is typically between about 0.60 millimeters and about 1.20 millimeters. The dimension D is typically about 3 millimeters.  
         [0021]     The durometer or elasticity of the rings  22  may be varied by changing the composition thereof. The rings  22  may be manufactured in a variety of colors to indicate variations in the cross sectional thickness and the durometer thereof. The rings  22  are preferably manufactured from a silicone material selected from the group consisting of TUFEL® II 94706 and LIM® 6040.  
         [0022]     Referring to  FIG. 4 , there is shown a stick  30  comprising a third embodiment of the invention. The stick  30  has a plurality of rings  32  secured to the opposite sides thereof by a plurality of rods  34 . Prior to utilization the rings  32  are separated from the rods  34  by cutting or breaking away, under pulling stress at the point of intersection therebetween.  
         [0023]     The rings  32  may also be used to ligate orthodontic archwires to orthodontic brackets. The dimensions of the rings  32  are similar to the dimensions of the rings  22  as illustrated in  FIG. 3  and described hereinabove in conjunction therewith.  
         [0024]     The durometer or elasticity of the rings  32  may be varied by changing the composition thereof. The rings  32  may be manufactured in a variety of colors to indicate variations in the cross sectional thickness and the durometer thereof. Similarly, different colors are desirable to patients offering color combinations that add flair or changeable colors for personal choice for variety. The rings  22  are preferably manufactured from a silicone material selected from the group consisting of TUFEL® II 94706 and LIM® 6040.  
         [0025]     Referring to  FIG. 5 , there is shown a fourth embodiment of the invention. In accordance with the fourth embodiment, a tube  40  is manufactured utilizing conventional plastic tube manufacturing techniques. As pointed out above in conjunction with the power bar  10 , the chain  20 , and the stick  30 , a composition of the tube  40  may be varied in order to change the durometer or elasticity thereof. Tubes  40  comprising the present invention may be manufactured in a variety of colors to indicate differences in durometer or resistivity, differences in thickness, and color changes purely for variety during treatment.  
         [0026]     In the practice of the invention the tube  40  is cut into a plurality of rings  42  utilizing any suitable cutting instrument. The rings  42  are similar in size and shape to the rings  22  of  FIG. 3  and the rings  32  of  FIG. 4 . The rings  42  may be utilized similarly to the power bar  10  as illustrated in  FIG. 2  and described hereinabove in conjunction therewith.  
         [0027]     Although preferred embodiments of the invention have been illustrated in the accompanying Drawings and described in the foregoing Detailed Description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications, and substitutions of parts and elements without departing from the spirit of the invention.