Dental prosthesis

Abstract

A dental prosthesis includes a dental implant, a post and core and a crown. The implant is adapted to be fixed to a bone and the post and core is adapted to be fixed to the implant with a screw that passes through the inside of the post and core, a first portion of the post and core including a first portion to be introduced into the implant and second portion protruding from the implant, providing a connection between the implant and the crown. A separation area is provided between the area where the crown is housed in the post and core and the area where the post and core is housed in the implant and the second portion of the post and core has a profile that converges from the implant toward the crown, without increases.

Claims

1. A dental prosthesis comprising: a dental implant; a post and core; and a crown, wherein said implant being is adapted to be fixed to a bone, and said post and core is adapted to be fixed to said implant with a screw that passes through an inner portion of said post and core, wherein said post and core comprises a first portion to be inserted into said implant and a second portion protruding from said implant, wherein said post and core connects said implant to said crown, a separation area being provided between a first area where the crown is housed in the post and core and a second area where the post and core is housed in the implant, and wherein an outer profile of said second portion converges from said implant towards said crown, without increases.

2. The dental prosthesis according to claim 1, wherein said outer profile further comprises a first lower cylindrical part, a second converging part being disposed above said first cylindrical part.

3. The dental prosthesis according to claim 1, wherein said outer profile converges in a continuous manner from said implant towards said crown, without increases.

4. The dental prosthesis according to claim 1, wherein said outer profile converges with an angle of convergence included between 1 and 6.

5. The dental prosthesis according to claim 4, wherein said outer profile converges with an angle of convergence equal to 2.

6. The dental prosthesis according to claim 1, wherein said crown is adapted to be fixed to said post and core through cementation.

7. The dental prosthesis according to claim 1, wherein said post and core has no margins.

8. The dental prosthesis according to claim 1, wherein said post and core is provided with an ascending microscopic thread that starts in proximity to the implant.

9. The dental prosthesis according to claim 8, wherein a width of said microscopic thread is included between 4 m and 100 m.

10. The dental prosthesis according to claim 9, wherein the width of said microscopic thread is at least equal to 20 m.

11. The dental prosthesis according to claim 8, wherein a depth of said microscopic thread is included between 4 m and 60 m.

12. The dental prosthesis according to claim 11, wherein the depth of said microscopic thread is at least equal to 20 m.

Description

[0026] In order for the reader to better understand the invention, an example of embodiment of the same is described here below by way of non-limiting example, with reference to some drawings.

[0027] FIG. 1a shows a sectional view of an embodiment of a prosthetic post and core with a fully converging protruding portion.

[0028] FIG. 1b shows a sectional view of an embodiment of a prosthetic post and core whose protruding portion in turn comprises a first cylindrical lower part () and a second converging upper part ().

[0029] FIG. 2 shows a front view of a dental prosthesis with a post and core of the known type with margin or shoulder.

[0030] FIG. 3 shows a front view of the post and core of FIG. 1 fixed to an implant inserted in a bone and having a crown placed on it, wherein the contour of the post and core is highlighted with respect to the other elements so as to show its position within the crown.

[0031] FIG. 4 shows a front view of two dental prostheses. The left prosthesis corresponds to a known post and core with margin or shoulder and the right prosthesis corresponds to a prosthetic post and core according to the present invention, illustrated schematically (the micro thread is not shown).

[0032] The prosthetic post and core 1 shown in FIGS. 1a and 1b is hollow and is internally provided with two areas that extend in the direction of its axis of symmetry. On one side there is the duct 5, which is sufficiently wide to allow the head of a screw to pass therethrough. Said screw head remains fixed in the cavity 6 and the rest of the screw is housed in the connection element 4, the portion of the post and core 1 that is inserted in the implant. The sides that surround the cavity 6 are thicker than those of the duct 5, for the purpose of offering increased resistance to loads.

[0033] On the other hand, the diameter of the post and core 1 of FIG. 1a converges upwards over the entire portion protruding from the implant, that is, starting from the connection element 4. As can be observed, the angle of convergence is equal to 2. In the part that is closest to the connection element, the post and core 1 is provided with an ascending micrometric thread 2 that starts immediately after the connection element 4.

[0034] Alternatively, as shown in FIG. 1b, the post and core 1 is provided with a first lower cylindrical part (), meaning a part with constant diameter, and a second upper part () with diameter converging upwards.

[0035] Once the post and core 1 has been joined to the implant, the duct 5 must be filled with a resin-based material in order to seal the cavity and prevent the introduction or release of bacteria through the inside of the post and core 1.

[0036] A typical post and core known in the art has a margin or shoulder such as, for example, that indicated by the numeral 50 in FIG. 2. The presence of the margin 50 implies that the diameter of the post and core 20 increases immediately after the implant 10, thus defining the margin or shoulder 50. The crown 30 has a part that comes to be fixed into the margin 50 of the post and core 20 and rests on the same, leaving the base of the crown 30 at the same level as the supporting line 90.

[0037] In the known post and cores like the one shown in FIG. 2, the narrowest area of the post and core 20, in the part located between the implant 10 and the crown 30, is exactly in the contact point between the post and core 20 and the implant 10. This causes the healed tissue to accumulate in this area and leads to the recession of the gum 40 that exposes the post and core 20, as can be seen in FIG. 2, thus negatively affecting the aesthetical appearance of the implant and exposing the gum to the proliferation of bacteria.

[0038] FIG. 3 shows the prosthetic post and core 1 that is the subject of the present invention joined to an implant 10 fixed to a bone 70, and with a crown 30 on the same. The area of interest corresponds to the part of the post and core 1 that is situated between the implant 10 and the crown 30. In FIG. 3 the contour of the post and core 1 is highlighted in order to show its position within the crown 30.

[0039] As can be observed, from the area of the post and core exposed to contact with the gum 40, the smaller diameter is exactly at the limit between the post and core 1 and the crown 30.

[0040] This causes the gum 40 to accumulate in the lower part of the crown 30 during the healing process and consequently, due to the separation of said lower part of the crown 30 from the implant 10, the quantity of tissue between the crown and the implant is larger than in the known post and cores, as shown in FIG. 4.

[0041] FIG. 3 shows how the gum 40 covers the post and core 1 completely, differently from that which happens with the post and cores known in the art, as that shown in FIG. 2. The numeral 80 indicates the portion of tissue that is fixed to the micrometric thread 2.

[0042] The left dental prosthesis in FIG. 4 uses a post and core with margin or shoulder 50 like those known in the art. The gum 40 covers a smaller part of the crown 30 and is closer to the implant compared to the prosthesis with the prosthetic post and core that is the subject of the present invention, shown on the right. The effect thanks to which the area with smaller diameter is further from the implant allows a larger quantity of tissue to be present between the implant 10 and the crown 30. This can be observed from the different position of the tissue fibres 60 in the two prostheses. In the case of the known post and core with margin (on the left), the fibres 60 are located in an area closer to the implant and with little contact with the post and core. On the contrary, in the case of the post and core according to the present invention (on the right), the fibres 60 adhere to the entire surface of the post and core and in an area closer to the crown, with more tissue between the crown and the implant compared to the prosthesis illustrated on the left.