ORTHODONTIC ARCHWIRE BRACKET
An orthodontic archwire bracket having a first body ( 10 ) with a base ( 11 ) configured to be fixed to a tooth and a second body ( 20 ) with a central hollow portion ( 25 ) and a slot ( 21 ) formed by two slot portions ( 21 a, 21 b ) on opposite sides of the central hollow portion ( 25 ). The slot ( 21 ) is configured to receive an archwire. A ball joint coupling connects the first and second bodies ( 10, 20 ). The second body ( 20 ) is made at least in part of a material with shape memory that maintains an original shape at body temperature thus locking the ball joint coupling, and acquires a deformable state at a temperature below body temperature. In one embodiment, the second body ( 20 ) further has retaining members ( 26 ) extending into each of the slot portions ( 21 a, 21 b ) next to an inlet thereof.
1 . An orthodontic archwire bracket, comprising a first body provided with a base configured to be fixed to a tooth and a second body provided with a main slot configured to receive an archwire, retaining means being provided to retain said archwire in said main slot, wherein;
the first and second bodies are connected to one another by a ball joint coupling;
the second body is made of a material with shape memory which maintains an original shape at a first temperature equivalent to body temperature and acquires a deformable state at a second temperature below body temperature;
the first and second bodies are sized such that said ball joint coupling is locked by friction between the first and second bodies when both are heated to said first temperature;
the second body includes a central hollow portion and said main slot comprises two main slot portions mutually aligned on opposite sides of said central hollow portion;
said retaining means comprise retaining members formed in the second body, said retaining members extending into each of said main slot portions next to an inlet thereof
the second body further comprises transverse slots connected with the main slot and extending therefrom to define arms at the ends of which there are said retaining members, said transverse slots facilitating deformation of the second body when the latter is in said deformable state; and
the ball joint coupling is a spherical ball joint coupling comprising at least one outer spherical surface portion formed on the first body and at least one inner spherical surface portion formed in said central hollow portion of the second body, and a part of the first body on which said outer spherical surface portion is formed is housed inside the central hollow portion of the second body.
2 . The archwire bracket according to claim 1 , wherein said retaining members are configured to retain said archwire in the main slot portions when the second body is in said original shape and to allow inserting and removing the archwire from the main slot portions by the deformation of the second body when the latter is at said second temperature below body temperature.
3 . The archwire bracket according to claim 1 , wherein the second body comprises one or more notches in a circumferential edge thereof, said notches facilitating the deformation of the second body when the latter is at the second temperature below body temperature.
4 . The archwire bracket according to claim 1 , wherein the first body comprises a secondary slot for receiving the archwire, said secondary slot of the first body being sized to allow movements of the second body together with the archwire housed in the main slot thereof with respect to the first body when the second body is at the second temperature below body temperature.
5 . The archwire bracket according to claim 1 , wherein the retaining members comprise outer inclined surfaces for facilitating insertion of the archwire under pressure and inner inclined surfaces for facilitating removal of the archwire under pressure when the second body is below body temperature.
6 . The archwire bracket according to claim 2 , wherein the retaining members comprise outer inclined surfaces for facilitating insertion of the archwire under pressure and inner inclined surfaces for facilitating removal of the archwire under pressure when the second body is below body temperature.
7 . An orthodontic archwire bracket, comprising a first body provided with a base configured to be fixed to a tooth and a second body provided with a main slot configured to receive an archwire, retaining means being provided to retain said archwire in said main slot, wherein;
the first and second bodies are connected to one another by a ball joint coupling;
the second body includes a central hollow portion and said main slot comprises two main slot portions mutually aligned on opposite sides of said central hollow portion;
the ball joint coupling is a spherical ball joint coupling comprising at least one outer spherical surface portion formed on the first body and at least one inner spherical surface portion formed in said central hollow portion of the second body, and a part of the first body on which said outer spherical surface portion is formed is housed inside the central hollow portion of the second body;
at least part of the second body is made of a material with shape memory which maintains an original shape at a first temperature equivalent to body temperature and acquires a deformable state at a second temperature below body temperature;
the first and second bodies are sized such that said ball joint coupling is locked by friction between the first and second bodies when both are heated to said first temperature.
8 . The archwire bracket according to claim 7 , wherein the second body is holly made of said material with shape memory and said retaining means comprise retaining members formed in the second body, said retaining members extending into each of said main slot portions next to an inlet thereof.
9 . The archwire bracket according to claim 8 , wherein the second body further comprises transverse slots connected with the main slot and extending therefrom to define arms at the ends of which there are said retaining members, said transverse slots facilitating deformation of the second body when the latter is in said deformable state.
10 . The archwire bracket according to claim 8 , wherein said retaining members comprise outer inclined surfaces for facilitating insertion of the archwire under pressure and inner inclined surfaces for facilitating removal of the archwire under pressure when the second body is at the second temperature below body temperature, and the retaining members retain said archwire in the main slot portions when the second body is in said original shape at the first temperature equivalent to body temperature.
11 . The archwire bracket according to claim 7 , wherein the second body comprises one or more notches in a circumferential edge thereof, said notches facilitating the deformation of the second body when the latter is at the second temperature below body temperature.
12 . The archwire bracket according to claim 7 , wherein the first body comprises a secondary slot for receiving the archwire, said secondary slot of the first body being sized to allow movements of the second body together with the archwire housed in the main slot thereof with respect to the first body when the second body is at the second temperature below body temperature.
13 . The archwire bracket according to claim 7 , wherein the second body is comprised of a main second body part and a ring second body part, said ring second body part being fit around on an outer perimetral surface of the main second body part, only said ring second body part being made of said material with shape memory, said main second body part having said central hollow portion with said inner spherical surface portion formed therein, the central hollow portion being surrounded by a perimetral wall portion interrupted by a slit providing a gap.
14 . The archwire bracket according to claim 13 , wherein said outer perimetral surface on which the ring second body part is fit around is provided on a perimetral recess formed in the perimetral wall portion of the main second body part.
15 . The archwire bracket according to claim 14 , wherein said perimetral recess is formed next to one end of the main second body part opposite to the main slot portions, and has a sinuous edge accommodating the main slot portions, and the ring second body part has a ring sinuous edge conforming said sinuous edge of the perimetral recess.
16 . An orthodontic archwire bracket, comprising a first body provided with a base configured to be fixed to a tooth and a second body provided with a main slot configured to receive an archwire, retaining means being provided to retain said archwire in said main slot, wherein;
the first and second bodies are connected to one another by a ball joint coupling;
the second body is comprised of a main second body part and a ring second body part, said ring second body part being fit around on an outer perimetral surface of the main second body part;
the main second body part includes a central hollow portion surrounded by a perimetral wall portion interrupted by a slit providing a gap;
said main slot comprises two mutually aligned main slot portions formed in said perimetral wall portion on opposite sides of said central hollow portion;
the ball joint coupling is a spherical ball joint coupling comprising at least one outer spherical surface portion formed on the first body and at least one inner spherical surface portion formed in the central hollow portion of the main second body part, and a part of the first body on which said outer spherical surface portion is formed is housed inside the central hollow portion of the main second body part;
said ring second body part is made of a material with shape memory which maintains an original shape at a first temperature equivalent to body temperature and acquires a deformable state at a second temperature below body temperature;
the first body, the main second body part and the ring second body part are sized such that said ball joint coupling is locked by friction between the first body and the main second body part when the first and second bodies are heated to said first temperature.
17 . The archwire bracket according to claim 16 , wherein said outer perimetral surface on which the ring second body part is fit around is provided on a perimetral recess formed in the perimetral wall portion of the main second body part.
18 . The archwire bracket according to claim 17 , wherein said perimetral recess is formed next to one end of the main second body part opposite to the main slot portions, and has a sinuous edge accommodating the main slot portions, and the ring second body part has a ring sinuous edge conforming said sinuous edge of the perimetral recess.
19 . The archwire bracket according to claim 16 , wherein said retaining means comprise a retaining element which is movable between an open position, at which said retaining element allows the archwire to be inserted into and removed from the main slot, and a closed position, at which the retaining element retains the archwire in the main slot.
20 . The archwire bracket according to claim 19 , wherein the main second body part has formed therein guide lugs guiding rotational movements of the retaining element between said open and closed positions.