The present invention relates to a dental implant fixing system, particularly to a dental fixing implant system used for implanting surgery for fixing a prosthetic tooth in an artificial tooth root of an oral alveolar bone.
In conventional implanting surgery, a dental implant (or an artificial tooth root) is embedded in the oral alveolar bone of a patient, then a prosthetic tooth is positioned in the gums of the patient.
A conventional implant usually has a cylindrical shape, having an outer thread division at a lower section, which is screwed into the oral alveolar bone of the patient's mouth. The thread division has an abutment on a top thereof to accommodate a prosthetic tooth over the dental implant.
The process of implant surgery has two phases: firstly, drilling into the alveolar bone, generating a pre-drilled hole; secondly, screwing an implant in the hole inside the alveolar bone. In an early period of screwing, when the alveolar hone still has no osseointegration with the dental implant, a stress-free period is required to avoid a micro-motion which can cause loosening of new bone tissue. So after the dental implantation, the gum usually will be temporarily sutured. It is waited until osseointegration is finished, then the second phase is performed: opening the gum, fixing an abutment in the dental implant, finally manufacturing a prosthetic tooth over the abutment.
For improving stability of implantation in alveolar bone as well as promoting osseointegration between implant and alveolar bone, the thread division of conventional implant is usually designed as a self-tapping thread, having grooves as sharp incisions on its end part, so that the thread division tightly engages with the alveolar bone when screwed into the pre-drilled hole of the alveolar bone. Thereby, resistance by implanting is reduced and stability after implantation is achieved.
However, such an conventional implant usually has a lower end under the thread division which is planar or curved. Accordingly, when the thread division is screwed into the pre-drilled hole in the alveolar bone, bone chips, which accumulate on the lower end of the thread division, cause increasing resistance, so that more clamping force is required.
Clamping torque resulted by screwing has to be limited, since in case of high strength, heat resulting from friction between the thread division and the alveolar bone causes occasions necrosis of the alveolar bone. Furthermore, increasing pressure between the thread division and the alveolar bone resulting form the resistance by the bone chips causes crumbling of the implanted location, even breaking of the implant.
Besides, for improving stability of implantation in the earlier period, and furthering osseointegration between implant and alveolar hone, in conventional art occasionally a recessed screw is set at the lower end of the thread division of the implant. When the thread division is screwed into the pre-drilled hole, bone chips below the implanting hole are driven into the recessed screw, inducing growth of the alveolar bone and filling the recessed screw. So is osseointegration achieved.
Since in an conventional implant the lower end of the thread division is planar or curved, bone chips from the implanting hole accumulated undebelow the lower end of the thread division do not easily get into said recessed screw. Therefore, the effect of the recessed screw for osscointegration is limited.
The main object of the present invention is to provide a dental implant fixing system for reducing clamping torque and promoting complete osseointegration, so that a higher success rate of implanting surgery is achieved.
For achieving above objects, the present invention comprises an implant, having a cylinder main body with an outer thread division to be screwed into the oral alveolar bone of a patient; characterized in that: the thread division has an end part at a bottom, with a recessed conial screw located at a frontal central position at the end part which has a conical shape, narrowing from top to bottom; where the conial screw has a relatively narrow diameter on a top end and a relatively wide diameter on a bottom end thereof. Thus a wall of the conial screw and an outer side of the end part approach each other inclined at bottom.
In this way, the thickness of a gap between the opening of the conial screw and the outer side of the end part of the thread division is reduced. Reduced resistance of implanting results. Furthermore, width and area of the bottom are also reduced, and accumulation of bone chips at bottom is avoided. Accordingly bone chips can easily get into the conial screw for promoting osseointegration.
Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the present invention.
As shown in
As shown in
The main characteristics of the present invention are: the end part 15 of the thread division 12 has a conical shape, narrowing from top to bottom, and the conial screw 17 with a narrower diameter on top and a wider one at bottom. So the wall of the conial screw 17 and the outer side of the end part 15 approach each other inclined at bottom. Therefore, the thickness of a gap between the opening of the conial screw 17 and the outer side of the end part 15 of the thread division 12 reduces. As shown in
According to the system mentioned above, the clamping torque loaded on the end part 15 through implanting reduces. So the implant of the present invention can prevent heat generated by excessive resistance and promote success rate of implanting surgery. Besides, due to reduced width and area of the lower end 16, bone chips will not easily accumulate at bottom of the lower end 16, so more bone chips can get inside within the conial screw 17. A stable osseointegration between the alveolar bone and the conial screw 17 is achieved.
Furthermore, regarding sufficient strength on the end part 15 of the thread division 12 and reduced accumulation of bone chips, preferably the width of the lower end 16 is kept in the range 0.2 mm˜1 mm, since an over narrow lower end 16 can cause weakness of the thread.
The implant 10 in the first embodiment of the present invention is a multistage design, that is, the implant 10 and the abutment 20 for mounting the prosthetic tooth 30 are separated objects. As shown in
During normal implanting surgery, once the implant 10 is embedded in the implanting hole, gums are firstly sutured. After osseointegration is performed, the surgery will be handled again, let the implant 10 extend beyond the gums. Then the abutment 20 is jointed over the neck part 13. Thereafter, the prosthetic tooth 30 will be mounted over the abutment 20.
The second as well as the first embodiment of the present invention have the same characteristics, that is, the thread division 12A, main body 11A, end part 15A, conial screw 17A, lower end 16A have the same characteristics as the thread division 12, main body 11, end part 15, conial screw 17 and lower end 16, respectively. Accordingly, their description is omitted.
The present invention allows higher success rate of implantating surgery and furthermore a more complete osseointegration. While preferred embodiments of the invention have been set forth for the purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments, which do not depart from the spirit and scope of the invention.