Abstract:
A dental abutment is provided with an axial through hole and is fastened at a lower segment thereof with an implant in conjunction with a cement which is infected into a threaded hole of the implant. An excess amount of the cement is forced out via the axial through hole of the abutment such that the cement is deposited on a flat top of the abutment to facilitate the removing of the cement residue and to minimize the likelihood of a gums inflammation which may be resulted from an incomplete removal of the cement residue.

Description:
FIELD OF THE PRESENT INVENTION 
   The present invention relates generally to a tooth implantation, and more particularly to an abutment structure which is designed to enhance efficiency of the tooth implantation, and to minimize the likelihood of the post-operational gums inflammation which is resulted from an incomplete removal of cement. 
   BACKGROUND OF THE PRESENT INVENTION 
   Referring to  FIG. 1  of the drawing, a prior art dental abutment  10  has an upper segment  11 , and a lower segment  12  which is provided at the free end with male threads  121 . The upper segment  11  is dimensioned to fit into a tooth “T”, while the lower segment  12  is fastened with an implant  20  such that the male threads  121  of the lower segment  12  are engaged with female threads  22  of a cavity  21  of the implant  20 . The engagement is reinforced by a cement “G” which is injected into the cavity  21 . 
   As shown in  FIG. 2 , a socketed bone “I” is provided with a socket into which the implant  20  is fitted. In other words, the tooth “T” is implanted in the bone “I” in conjunction with the abutment  10  and the implant  20 . In view of the fact that the application of the cement “G” can not be easily controlled with precision in terms of quantity of the cement “G”, it is therefore likely that an excessive amount of the cement is injected into the cavity  21  of the implant  20 , thereby resulting in the spilling of the cement “G”. The cement residue is often deposited on the outer surface of the lower segment  12  of the abutment  10 , as well as on the top end of the implant  20 , as shown in an enlarged view of a circled portion of FIG.  2 . In the event that the cement residue is not removed properly, the socketed bone “I” and the tissue surrounding the socketed bone “I” will fail to grow together intimately. Such a mishap often results in a gums inflammation, or a situation in which the implant  20  is apt to become loosened by a chewing action. In order to avert such an operational deficiency as described above, a complete removal of the cement residue from the lower segment  12  of the abutment  10  and the top end of the implant  20  is called for at the expense of the patient. 
   The abutment  10  described above is used in an upright manner in the molar implantation; nevertheless it is not suitable for use in the incisor implantation. As shown in  FIGS. 3A ,  3 B, and  3 C, the socketed bone “I” of the incisor has an inclination. Accordingly, the implant  20  must be inserted into the socketed bone “I” at an angle θ corresponding to the inclination of the socketed bone “I”, as shown in FIG.  3 A. As a result, an abutment  100  with an inclination is used to implant an incisor “T”. The abutment  100  is provided in the center with an axial through hole  101  and is fastened with the implant  20  by a fastening screw “S” which is engaged with the female threads  22  of the cavity  21  of the implant  20  via the axial through hole  101  of the abutment  100 , as illustrated in FIG.  3 B. The abutment  100  is further provided in the lateral side of the upper segment thereof with a lateral threaded hole  102 . The abutment  100  is fastened with the incisor “T” by another fastening screw “S” which is engaged with the lateral threaded hole  102 , as shown in FIG.  3 C. 
   Referring to  FIG. 4A  of the drawing, the implantation angle θ is likely deviated in the implantation operation of the implant  20  such that the implantation angle θ 1  may be too large, as shown in  FIG. 4B , or that the implantation angle θ 2  may be too small, as shown in FIG.  4 C. Such angular deviations as described above often result in failure of implantation. With the purpose of overcoming the drawback of the angular deviation, a variety of abutments  100 ,  110 ,  120 , etc, must be prepared at additional cost, which is of course passed on to the patient under treatment. The pre-operational X-cay diagnosis is of a little help in determining the implantation angle of the implant  20  in conformity with the specification of the abutment  100 . In addition, there is lack of a standardized implantation method by which the implant  20  is always implanted into the socketed bone “I” at a correct angle. As a result, the abutment  100  must be mended by the dental technician at additional cost. 
   SUMMARY OF THE PRESENT INVENTION 
   The main objective of the present invention is to provide an abutment, which is provided in the center with an axial through hole enabling the excess amount of cement to be discharged from the upper segment of the abutment, thereby averting the deposit of the cement residue in the outer surface of the lower segment of the abutment and in the top of an implant. The cement residue can be thus easily removed to prevent the gums inflammation. 
   Another objective of the present invention is to provide an abutment structure comprising a crown and a fixation pin. The crown and the upper segment of the abutment are fastened together by the fixation pin and can be removed for cleaning. 
   Another objective of the present invention is to provide an abutment structure comprising a crown and a fixation pin, by which the abutments of various inclinations can be used in the implantation of an implant into an incisor socketed bone without the angular deviation. The abutment can be joined together with the crown by the fixation pin in various manners, thereby reducing the cost of molding the artificial tooth as well as the abutment inventory. 
   The features, functions and advantages of the present invention will be more readily understood upon a thoughtful deliberation of the following detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
       FIG. 1  is a schematic view of a conventional abutment, along with an implant. 
       FIG. 2  is a sectional schematic view of the conventional abutment which is implanted into a socketed bone in conjunction with the implant. 
       FIG. 3A  is a schematic view of the conventional abutment which is implanted into an incisor socketed bone in conjunction with the implant at implantation angle θ. 
       FIG. 3B  is a schematic view of the conventional abutment which is implanted into an incisor socketed bone in conjunction with the implant, according to the above prior art abutment of FIG.  3 A. 
       FIG. 3C  is a schematic view of the conventional abutment which is implanted into an incisor socketed bone in conjunction with the implant, according to the above prior art abutment of FIG.  3 B. 
       FIG. 4A  is a sectional schematic view of the conventional implant which is inserted into the incisor socketed bone with the implantation angle θ. 
       FIG. 4B  is a sectional schematic view of the conventional implant which is inserted into the incisor socketed bone with the implantation angle θ 1 . 
       FIG. 4C  is a sectional schematic view of the conventional implant which is inserted into the incisor socketed bone with the implantation angle θ 2 . 
       FIG. 5  is a schematic plan view of an abutment structure, along with an implant, according to a first preferred embodiment of the present invention. 
       FIG. 6  is a sectional schematic of an abutment structure, which is joined with the implant, according to the above first preferred embodiment of the present invention. 
       FIG. 7A  is a sectional schematic view of an abutment structure, according to a second preferred embodiment of the present invention. 
       FIG. 7B  is a sectional schematic of an abutment structure, which is joined with the implant, according to the above second preferred embodiment of the present invention. 
       FIG. 8A  is a sectional schematic view of an abutment structure, according to a third preferred embodiment of the present invention. 
       FIG. 8B  is a sectional schematic of an abutment structure, which is joined with the implant, according to the above third preferred embodiment of the present invention. 
       FIG. 9  is a sectional schematic view of the lower segment of an abutment structure, according to the above each preferred embodiment of the present invention. 
       FIG. 10  is an exploded view of an abutment structure, along with a crown and a fastening pin, according to a fourth preferred embodiment of the present invention. 
       FIG. 11A  is a sectional schematic view of an abutment structure, which is joined with the implant and the crown, according to the above fourth preferred embodiment of the present invention. 
       FIG. 11B  is a sectional schematic view of an abutment structure, which is used in a molar tooth implantation, according to the above fourth preferred embodiment of the present invention. 
       FIG. 12A  is a sectional schematic view of an abutment structure, which is joined with the crown by a screw, according to the above fourth preferred embodiment of the present invention. 
       FIG. 12B  is a sectional schematic view of an abutment structure, which is used in a molar tooth implantation, according to the above fourth preferred embodiment of the present invention of FIG.  12 A. 
       FIG. 13  is a series of schematic views regarding the steps by which the present invention is embodied. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIG. 5  of the drawing an abutment structure according to a first preferred embodiment of the present invention is illustrated. The abutment  30  has an upper segment  31  which is of conical construction and is provided with a flat top. The abutment  30  has a lower segment  32  which is or a columnar construction and is smaller in diameter than the upper segment  31 . The lower segment  32  is provided at a bottom end with male threads  321 . The lower segment  32  is further provided in the center with an axial through hole  33  extending through the bottom end of the lower segment  32  toward the top of the upper segment  31 . As illustrated, the axial through hole has a uniform diameter along its length. 
   As shown in  FIG. 6 , the implantation according to a preferring embodiment of the present invention is similar in operation to the current tooth implantation. An implant  40  is first inserted into a socketed bone I. The implant  40  is provided With a threaded hole  41  into which a cement G is injected. The abutment  30  is then joined with the implant  40  such that the male threads  321  of the lower segment  32  of the abutment  30  are engaged with the female threads  42  of the threaded hole  41  of the implant  40 , and that the tip of the lower segment  32  comes in contact with the bottom end of the threaded hole  41 . The engagement of the male threads  321  with the female threads  42  is reinforced by the cement G. The excess amount of the cement G is forced out of the threaded hole  41  via the axial through hole  33  of the abutment  30 , as shown in an enlarged view of FIG.  6 . The excess amount of the cement is thus discharged and then deposited on the top of the upper segment  31  of the abutment  30 . As a result, the cement deposit can be easily removed without impairing the surrounding gums tissue. 
   Referring to  FIGS. 7A and 7B  of the drawings, an abutment  50  according to a second preferred embodiment of the present invention is illustrated. The abutment  50  has a lower segment  52  which is provided in the center of the bottom end thereof with an axial hole  53 . The abutment  50  has an upper segment  51  which is provided with a radial hole  54  in communication with the axial hole  53 . The radial hole  54  is provided with female threads  541  and fastened the tooth T with the upper segment  51  of the abutment  50  by a screw S. 
   As shown in  FIGS. 8A and 8B , an abutment  70  according to a third preferred embodiment of the present invention is illustrated. The abutment  70  has a lower segment  72  which is provided in the center of the bottom end thereof with an axial hole  73 . 
   The abutment  70  further has an upper segment  71  which is provided with a radial through hole  74  in communication with the axial hole  73 . The radial through hole  74  is provided in one end with female threads  741  and fastened the tooth T with the upper segment  71  of the abutment  70  by a screw S. 
   As shown in  FIG. 9 , the abutments  30 ′,  50 ′, and  70 ′ according to the above each preferred embodiment of the present invention is illustrated, the abutments  30 ′,  50 ′, and  70 ′ have respectively an inverted conical lower segment  32 ′,  52 ′,  72 ′. 
   As shown in  FIG. 10 , an abutment structure according to a fourth preferred embodiment of the present invention is illustrated. The abutment structure comprises an abutment  70 , a crown  60 , and a retention pin  80 . The crown  60  is a hollow conical construction and is provided with a flat top. The crown  60  is fitted over an upper segment  71  of the abutment  70 . The upper segment  71  is provided with a radial through hole  74 . The crown  60  is provided with two radial through holes  61  corresponding to the radial through hole  74  of the upper segment  71 . The crown  60  is fastened with the upper segment  71  of the abutment  70  by the retention pin  80  which is put through the radial through holes  61  and  74 . 
   Referring to  FIGS. 11A , and  11 B of the drawings, the abutment  70  according to the fourth preferred embodiment of the present invention is illustrated. The abutment  70  is used in a molar tooth implantation in which the crown  60  is first fitted over the upper segment  71  of the abutment  70  such that the crown  60  is so turned as to enable the two radial through holes  61  of the crown  60  to be in alignment with the radial through hole  74  of the upper segment  71  of the abutment  70 , The crown  60  is then fastened with the upper segment  71  by the retention pin  80  which is received in the radial through holes  61  and  74 . 
   The crown  60  serves as an inner crown t of the abutment  70  to facilitate the molding of a tooth T 1 , as shown in FIG.  11 B. The tooth T 1  is detachable. In the event that the tooth T 2  is fixed, the crown  60  and the abutment  70  is respectively provided with a threaded hole  62  and  75  for fastening tooth T 2  with the crown  60  by a fastening screw S which is engaged with the threaded hole  62  and  75 , as shown in  FIGS. 12A and 12B . 
   As shown in  FIG. 13 , the crown  60  and the abutment  70  of the present invention is used in the implantation of an incisor tooth, the following steps are taken.
         a. The dentist in charge of the implanting operation does not have to calculate precisely the implanting angle θ. The dentist should be able to insert an implant  40  into an incisor socketed bone I′, as shown in A view of FIG.  13 .   b. Upon completion of the fusion of the implant  40  with the tissue of the incisor socketed bone I′, the lower segment  72  of the abutment  70  is fastened into an inner cavity  41  of the implant  40 , as shown in B view of FIG.  13 .   c. The dentist determines and marks an inclination area on the upper segment  71  of the abutment  70 , as indicated by the doted lines in C view of FIG.  13 . before the abutment  70  is so turned as to separate from the implant  40 . The abutment  70  with the marked inclination area, the crown  60 , and the retention pin  80  are then processed and finished by the dental technician such that an abutment  701  with a desired inclination δ, and a crown  60 ′ with a desired inclination δ are produced, as shown in D view of FIG.  13 .   d. The abutment  701  and the crown  60 ′ are fastened together by the retention pin  80  such that the crown  60 ′ is kept in an upright position, as shown in E view of FIG.  13 .   e. If an incisor tooth T′ 1  is to be detachable, the crown  60 ′ serves as an inner crown of the abutment  701 . They are processed by the dental technician to form an outer crown t of the incisor tooth T′ 1 , as shown in F view of FIG.  13 .   f. If an incisor tooth T′ 2  is to be fixed, the crown  60 ′ is provided by drilling with a threaded hole  63 , and the fastening of the crown  60 ′ with the incisor tooth T′ 2  is done with a fastening screw S, as illustrated in F′ view of FIG.  13 .       

   The embodiments of the present invention described above are to be regarded in all respects as being illustrative and nonrestrictive. Accordingly, the present invention may be embodied in other specific forms without deviating from the spirit thereof. The present invention is therefore to be limited only by the scopes of the following claims.