Prosthetic retention system for edentulous patients consisting of a prefabricated bar and two implants

Abstract

A prosthetic retention system for edentulous patients comprising a prefabricated bar and two implants; where the said bar consists of a tubular central piece that has a round or ovoid cross section and two hollow capsules at its ends; and where the implants are formed by one single piece, with an upper zone that connects to the bar and a lower zone that is introduced into the patient's bone tissue.

Claims

1. A prosthetic retention system for edentulous patients, which does not require the use of cement or screws, comprising: a bar and two implants, each implant comprises an upper zone, a lower zone and a cylindrical-conical section between the upper zone and the lower zone; the upper zone comprises an implant head, a base with a bezel and a convex zone between the implant head and the base; the lower zone corresponds to the part that is introduced into the patient's bone tissue; the bar comprises: a tubular central part having a round or ovoid cross section of 1-2 mm in diameter; a hollow capsule at each end of the bar, the hollow capsule having a conical shape slightly larger than an implant head and a groove which allows the bar to be inserted by applying pressure in the upper zone of the implants, wherein the bar has a predetermined nonadjustable fixed length; wherein the implants are adapted to be parallel to each other, at the same height and centered on the bone tissue; and wherein the hollow capsule at each end of the bar is separated by a fixed distance of 10-25 mm between their centers.

2. The prosthetic retention system for edentulous patients according to claim 1, wherein the grooves take up a part or all of the face of the bar, leaving one or both sides partially or totally open.

3. The prosthetic retention system for edentulous patients according to claim 1, wherein the bar is made from a titanium alloy or surgical steel.

4. The prosthetic retention system for edentulous patients according to claim 1, wherein the upper zone of each implant further comprises an upper hexagonal piece and a lower hexagonal piece joined by the convex zone, wherein the upper hexagonal piece corresponds to an implant head and has a contour of rounded angles, and wherein the lower hexagonal piece has flat faces that match the faces of an implant head.

5. The prosthetic retention system for edentulous patients according to claim 4, wherein each implant head locks with and fixes a capsule of the bar and wherein the convex zone that connects the upper hexagonal piece and the lower hexagonal piece retains an O-ring when an implant is used individually.

6. The prosthetic retention system for edentulous patients according to claim 1, wherein the capsules of the bar are separated by a fixed distance of 11 mm.

7. The prosthetic retention system for edentulous patients according to claim 1, wherein a guide-forceps is required to insert the two implants to keep them parallel to each other, at the same height and centered on the bone tissue of the patient.

Description

(1) FIG. 1 shows the prosthetic retention system according to the invention.

(2) FIG. 2 shows the implants according to the invention.

(3) FIG. 3A shows the guide-forceps used to carry out the perforations for the implants.

(4) FIG. 3B shows a telescopic insertion support used to insert the implants.

DESCRIPTION OF THE INVENTION

(5) The present technology consists of a prosthetic retention system for edentulous patients that comprises a prefabricated bar and two implants. FIGS. 1 and 2 will be used as a reference for a better understanding of the invention.

(6) The bar (1) consists of a tubular central part (2) preferably made from a titanium alloy or surgical steel, which has a round or ovoid cross section of between 1 and 2 mm in diameter. At its ends it has two hollow capsules (3), with a distance of between 10 and 25 mm from center to center (ideally 11 mm), with a conical shape slightly larger than the implant heads, which can have a groove (4) on one or both sides. These grooves (4) take up a part or all of the side of the bar (1), leaving one or both sides partially or totally open for opening one end in case it is necessary to remove the bar and to facilitate flexibility in this zone during insertion.

(7) The implants (5) are made from one piece, preferably from a TiAlV alloy that can be thermally treated for improved mechanical properties. The implants consist of an upper zone (6) referred to as the implant connection, formed by 2 hexagonal pieces (9) joined by a convex central part (8) enabling O-ring retention if the implant is used individually. The upper hexagonal part, corresponding to the implant head, has a contour of rounded angles (7), and the lower hexagonal part has flat faces matching those of the implant head and preventing rotation when inserting the implant. At the base of the upper zone there is a bezel (10) useful for adjusting the bar capsules (3).

(8) The lower zone of the implants, corresponding to the part that is introduced into the tissue, has a smooth cylindrical-conical section of 1.5-4 mm in diameter that is in contact with the gums (12), and a rough section that is in contact with the bone tissue (13) formed by an elongated body of between 10 and 20 mm in length, with a cylindrical-conical shape of 1-2 mm in diameter, with a double thread that increases in width with distance from the implant point.

(9) The system is completed when the bar (1) is inserted into the upper end (6) of the implants. The bar is inserted applying pressure and remains in place due to the larger diameter of the head (7) of the implants, adjusting to the bezel of the base (10) and thus creating a single system (11) that does not require cement or screws.

(10) The head (7) of the implant enables capsule fixation (3), and the convex part connecting the hexagonal pieces can be used for O-ring retention if the implant is used individually without the bar.

(11) For correct system operation, it is recommended that forceps be used to guide the positioning of the implants to ensure that they are parallel, at the same height, and centered on the bone.

(12) The system does not require special screws for fixation, provides long-term stability optimizing clinical behavior after insertion, facilitates immediate loading, and does not require laboratory work. In addition, the bar (1) provides optimal prosthesis stabilization, reduces long-term prosthetic complications and associated costs, and can be removed if necessary without having to change the implants.

(13) The benefits of this integrated system are: minimal use of instruments and equipment for insertion; simplicity, safety and precision, with a minimum number of components; improved biomechanical properties due to the stabilization bar; minimally invasive operation with minimal surgical risks; immediate loading; no incisions or convalescence required; lower treatment costs; and long-term clinical validation in a representative national sample consisting of public health patients.
Application Examples

(14) In order to provide long-term treatment with reduced trauma, complexity and costs for edentulous patients, an integrated system was developed for stabilizing dental prostheses, comprising two implants and a prefabricated prosthetic bar. In addition, instruments such as a 3D positioning guide-forceps and a telescopic insertion support were used to facilitate insertion.

(15) The surgical procedure used to verify the effectiveness of the technology is described below (see FIG. 3):

(16) First, infiltration local anesthesia was applied and a guide-forceps (1) was used to measure the thickness of the osseous tissue in the implant area. This guide-forceps made it possible to carry out perforations for the implants in a minimally invasive fashion, without the need for a gum flap. Perforations were carried out with 1 mm drills (2) in the center of the mandible and in areas with a minimum bone thickness of 2 mm.

(17) Then, the first implant (3) was inserted and the position of the forceps was changed, it being supported on the head of the implant, after which the second perforation was made. The telescopic insertion support (4) was subsequently introduced into the head of the first implant and the second implant (3) was inserted. The heads of both implants were adjusted to ensure that they were at the same height and at a distance of 11 mm from one another. The prosthetic bar was inserted onto the heads of the implants and remained locked into place.

(18) After the prosthetic bar was installed, the pre-existing prosthesis of the patient was adapted and the retention clip was fixed by hollowing out the part of the prosthesis where the bar with the clip is fixed. Subsequently, the bar was covered with perforated rubber covering the gingiva, revealing the retention zones of the clip through the perforation and exposing the part of the clip to be fixed to the prosthesis. Finally, acrylic was applied to the hollowed zone of the prosthesis and placed on the rubber, so that the flaps of the clip were fixed to the prosthesis. In addition to providing prosthetic retention, the bar also improved the system's biomechanical properties, with clinical behavior equal to or better than conventional implants.

(19) This procedure was validated in a randomized controlled clinical trial lasting 5 years in which 90 implants were inserted into 45 completely edentulous elderly patients being treated in the public health care system. Each patient received two implants in the anterior mandible through a procedure carried out without incisions that was completely guided to reduce surgical risks. Immediately after insertion, the bars were connected to retain the prosthesis to the patient's half. The other half was left with an O-ring retention system.

(20) The degree of success of the bar system was 97.7%, higher than conventional implant systems with a documented success rate of 90%-95% after five years. The insertion procedure lasted approximately 2 hours.