This descriptive report refers to a new configuration applied to dental implants of the cone morse fitting type, characterized by its conic cavity having a cross section of oval or elliptical geometry to fit the prosthetic connection and the fitted screw, converging in just one product the characteristic of bacterial sealing, typical of the cone morse fitting, but without, however, rotational freedom, and there are also the advantages of fixing a connection with a fitted screw. FIELD OF APPLICATION

The patent in quesϋon belongs to the technical sector of dentistry, specifically the segment of implant dentistry. BACKGROUND OF THE TECHNIQUE

A major advance in dentistry was the possibility of successfully substituting lost natural teeth for osseointegrated dental implants.

Initially, osseointegration would occur with the atraumatic installation of a titanium screw in the bone, followed by a long scarring period; in other words, it was a procedure with two stages.

Later, developments were focused on the creation of implant designs that allowed one monitoring mechanism for the installation of the implant and the subsequent connection to a pillar for prosthetic restoration.

One proposal used is the incorporation to the implant of an external hexagon, 0.7 mm in height and 2.7 mm in thickness, which allowed fitting of both the installer during the installation surgery of the implant as well as the connection for later prosthetic restoration.

With the huge expansion in the utilization of implants for oral rehabilitations - from the original application in completely edentulous arches or in partial elements, and even in unitary restorations - the original design of the external hexagon resulted in some clinical complications, such as the loosening of the screw and the abutment. Recently, with the change in technique for immediate load, the need arose for more elevated installation torques to obtain good primary stability. However, this may provoke microdeformations of the hexagonal implant, increasing the rotational freedom of the abutment, facilitating even further the loosening of the screw. Thus, the research in bioengineering, responsible for massive advances in implant dentistry, has evaluated the geometry of the prosthetic, dimensions and positioning of the implants, materials of the components, and the resultant forces from mastication and osseointegration. These factors may influence the success of the rehabilitating treatment with dental implants and have been considered in the projects for new implants.

The external hexagon offers various benefits and has become the industry standard; however, it is still responsible for some difficulties, both in relation to periodontal health as well as the mechanical stability of the prosthetic.

To overcome these limitations inherent to its design, some manufacturers have proposed a variety of alternative connections. These include the internal hexagon, the internal octogon, implants with internal canals, the cone morse, among others, with the objective of generating an anti-rotational effect, increasing the stability of the abutment, and, consequently, reducing the incidence of screw loosening. Dental implants have undergone many modifications after the 40 years of osseointegration by international practice. The effectiveness and efficiency of the osseointegrated implants, as well as their longevity and predictability, are no longer under discussion. During this entire period, the clinical recommendation and utilization of osseointegrated implants expanded rapidly for use in completely edentulous jaws to uses in fixed partial prosthetics, unitary prosthetic reconstructions, maxillofacials, and a range of other applications limited only by the surgeon's skill. For example, use of the immediate load technique. The clinical evolution in the use of implants directly influenced the structural alterations that these underwent over the years, aiming at optimizing the limitations encountered as their utilization expanded.

Thus, in a short period of time, a wide variety of implants were developed, and professionals in the area were able to opt for various models according to the clinical case, with the implants varying in diameter, height, surface, material, shape, and geometry of the implant/pillar interface. Each these options would have their own application, since there are implant projects available for countless numbers of clinical situations, so that the selection would be made according to the quality of the material, recommendation for use, and cost.

During the selection process when the clinic selects which of the implant systems to use, the following topics are observed: predictability of osseointegration; controlled clinical studies which validate the system's performance over time in different bone qualities and with more than one type of prosthetic reconstruction; optimal interaction of the surface with the bone tissue; prosthetic options and flexibility; cost/quality relationship; dimensional tolerance; sealing of interfaces and compatibility with peri-implant tissue; interface stability and stability of the surgical phase prosthetic screw and the easy handling and simple prosthetic and the easy handling optimal profile of emergency and esthetics.

In short, professionals should look for simple, refined engineering with a logical design that balances technology with scientific knowledge in the area of health.

Implants with the internal cone morse interface have been gaining ground in the industry, gradually substituting the hexagonal implants, whether external or internal.

These implants may be designed to be coupled to two distinct types of prosthetic components: the single piece, fixed to the implant through its threaded extremity; or a double piece, fixed to the implant through a fitted screw.

Their benefits range from mechanical stability and bacterial sealing to distancing the vertical gap from the bone tissue.

The cone morse implants coupled to single piece connections have very stable junctions and do not have any rotational freedom; therefore, loosening of the prosthetic connection is not a common occurrence. The displacement of the fulcrum to a deeper internal region (Figure 1) distributes the axial and lateral forces throughout the entire region of the internal cone, unlike the external hexagonal implant, in which these forces occur only on the screw. The biological sealing of the cone morse junction promotes close contact between the cone of the prosthetic pillar and the conic cavity of the implant. In normal conditions, the size of the gap impedes the development of bacterial colonies, which exert an important factor on the etiology of bone loss around the cervical portion of the implant.

Another point to highlight is the Platform Switch concept distancing the vertical gap from the bone tissue, thus reducing the stimulus for marginal bone loss (Figure 2). This characteristic of the pillar's diameter being smaller than the implant's diameter in the case of the cone morse increases the thickness of the mucous membrane, making it more stable and more natural in appearance.

The threaded implants require an anti-rotational mechanism for their insertion which, in the case of the cone morse implant, may be located on top of the implant or at the bottom of the cone. When located internally - that is, at the bottom of the cone morse - the internal angle should be wider and, to keep the lateral walls resistant, the cervical diameter of the implant must be greater than 4 mm; the ideal is 4,8 mm, thus hindering their use in reduced prosthetic spaces or even in limited bone thicknesses.

The non-threaded cone morse implants, fixed through a fitted screw, do not have an anti-rotational mechanism, which becomes troublesome since there is no reference in the patient's mouth which allows the dentist to know the exact position in which the prosthetic should be fixed. Thus, for there to be perfect alignment with the rest of the teeth as projected in the laboratory, a tool is used called a position index or matrix. This is an individual part generally made of resin which transfers the exact position of the prosthetic component from the laboratory model to the patient's mouth.

The process is further complicated in cases of multiple or total rehabilitation, since there are no lateral teeth which serve as positioning references. The connection with the single-piece threaded cone morse implant does not cause this problem.

In compensation, there is the need to apply greater torque during fixation of the connection so that the implant is sealed precisely. In addition, its design makes it difficult to personalize, forcing the industry to manufacture a great variety of models according to size, position, and inclination of the tooth.

The design of the double-piece cone morse implant, on the other hand, facilitates its personalization and, consequently, its adaptation to different cases.

Furthermore, to fix an implant with a double-piece prosthetic connection, the torque applied to the fitted screw is much lower, which avoids problems with fractures in fragile bone structures, as well as with the implant wearing down. MODEL FUNDAMENTALS

The model described aims at making public a new configuration applied to dental implants, which unites the sealing characteristics of the cone morse type implant and the fixing and personalization facilities of the double-piece connections using fitted screws; without, however, lending rotational freedom to the pillar, thus avoiding problems of prosthetic positioning and alignment.

This is possible by modifying the circular geometry of the cross section of the conic perforation of the implant for an elliptical or oval section. The same modification to the cross section should be applied to the prosthetic connection so that it fits perfectly in the implant. BRIEF DESIGN DESCRIPTION To better understand this CONFIGURATION APPLIED TO DENTAL IMPLANTS, references are made to the attached drawings, in which:

Figure 1 - Illustrates a longitudinal cut of the implant with the cone morse fitting and single-piece connection, with a dislocated fulcrum for the lower part of the connection.

Figure 2 - Illustrates a side view of an implant with the cone morse fitting in order to allow visualization of the distance from the vertical gap to the bone tissue. Figure 3 - Illustrates an upper view of the conventional cone morse implant; in other words, with the geometry of the circular cross section.

Figure 4 - Illustrates an upper view of the proposed cone morse implant; in other words, with the geometry of the oval cross section.

Figure 5 - Illustrates a view in the perspective of the proposed implant.

Figure 6 - Illustrates a view in the lateral perspective of the proposed implant, prosthetic connection, and fitted screw. MODEL FUNCTIONING

In accordance with what is illustrated in the attached figures, the CONFIGURATION APPLIED TO DENTAL IMPLANTS is comprised of an implant with a cone morse internal cavity, with geometry for this cavity that is oval or elliptical; in other words, the angle of inclination in the internal walls of the cone morse cavity corresponding to the palatal-vestibular region is greater than the angle of inclination of the cone morse cavity in the region corresponding to the mesial-distal walls, or vice-versa. Fitted to this implant by means of a fitted screw is the prosthetic connection, whose geometry in the transversal section is also elliptical, corresponding to the geometry of the implant cavity.

The fixation of the prosthetic connection may, depending on the model variation, be accomplished by applying pressure, without requiring a fitted screw. PREFERRED FUNCTIONING OF THE MODEL

As the geometry of the implant's transversal section is elliptical, the wall thickness of the implant in the area corresponding to the palatal-vestibular region (see Figure 5, item 1) is thinner than the walls of the smaller axis, corresponding to the mesial-distal region (see Figure 5, item 2). If this reduction in implant wall thickness is marked, its resistance may be compromised.

For this reason, the new proposed configuration has its functioning optimized when applied to dental implants with scalloped inclinations, as described in patent MU 7900730-9.

The implant model described by MU 7900730-9 has in its extreme upper end two inclined scalloped planes, giving the upper end of the implant the format of a cell, adaptable to the contours of the patient's gingival tissue.

Thus, the implant model mentioned above has thicker palatal- vestibular walls than the mesial-distal walls, precisely because of the scalloped cut and its cervical geometry.

Thus, increasing one of the axes of the circumference of the conical section, to achieve an elliptical geometry, does not compromise the wall thickness, since the palatal-vestibular walls, which will have their thicknesses further reduced, are, by nature, thicker. BIBLIOGRAPHICAL REFERENCES

- Carga lmediata Em lmplantes Osteointegrados: Possibilidades E Tecnicas [Immediate Load in Osseointegrated Implants: Possibilities and Techniques]. Padovan.Luis Eduardo Marques Sartori, Ivete Aparecida de MattiasThome, Geninho MeIo, Ana Claύ. Edicao : 1 ^ao /2008. Editora Santos.