Author: Prof. Rodrigo Melim Ferreira
In the early years of implantology, the greatest preoccupation lay on the osseointegration of implants. Branemark et al. (1969) published results of their laboratory experiments in animals. Those results clearly indicated that the direct anchorage of the implant into the bone tissue would be possible if certain directives were followed. In 1977, Branemark et al. published the first clinical article demonstrating their ten years of experience in the treatment of edentulous mandibles with osseointegrated implants. At this first moment of osseointegration, the implants were used to rehabilitate patients with large dental losses. In the first cases, four or five implants were installed to support total prostheses, denominated as protocol prostheses.
By then, treatments with implants were focused on the surgery because the greatest challenge was the obtainment of osseointegration. As the years went by, osseointegration became routine and implants began to be used in partial and single rehabilitations. However, problems began to appear due to the lack of prosthetic components for solving those cases. Therefore, the industry set out to develop new intermediate pieces to solve those issues. The positioning of implants, in some cases, continued to be very unfavorable for the making of prostheses that could combine esthetics, function and longevity.
Beginning of reverse planning
In face of that scenario, around 20 years ago, authors like Garber (1995), reported that, originally, implants were installed according to bone availability. Garber published an article describing a new surgical approach, according to which, the ideal final restoration would be planned and then a treatment plan that would make that restoration viable would be developed. That way of planning was called reverse planning and involves all necessary steps for the ideal tridimensional positioning of an implant.
According to Volpato et al. (2012), the prosthesis over implant is different from other modalities of prosthesis because it requires, besides prosthetic planning, the surgical planning for the installation of the implant. In that planning process, additional procedures for bone and/or gingival reconstruction may be needed for achieving adequate results from the point of view of esthetics and function.
Reverse planning may be carried out in several ways, varying according to the particularities of each clinical situation. For cases of single or partial prostheses, with or without bone and gingival tissue loss, what is generally done is the preliminary diagnostics waxing, which may be tested in the mouth by means of a mock-up and, later, transformed into a surgical guide (which can work also as a tomography guide) that will guide the installation of the implants in their ideal positions.
When it is necessary to manipulate or reconstruct bone and/or gingival tissue, the waxing will show the extent and volume of tissue lost, and will help in the planning to define if only the phase of the reconstruction will be done or if it will be viable to install the implants in the same appointment.
In extensive cases and in cases of rehabilitation of the total arch, when the patient still has teeth, a wax plan is usually made to diagnose its fitting (if the case allows). After that, the extraction of the teeth from the model can be carried out as well as the regularization of the remaining alveolar ridge and construction of the surgical guide. When the patient does not have any teeth, the procedure is the same as for a total prosthesis. It is necessary to make the wax model, assembly and fitting. At that moment, the professional requests the laboratory to transform that assembly into the surgical guide for the determination of the installation position of the implants.
Arcsys Implant System
Thinking of the evolution of implantology, FGM developed the Arcsys System to offer innovations that target the improvement and simplification of some prosthetic limitations of the present implant system by means of a compact line of customizable components that allows the professionals to solve the most diverse situations with a reduced stock of components.
Multifunctional Healing Abutments
The system counts on multifunctional healing abutments that are installed directly over implants and may be used for gingival conditioning or as support for temporary prostheses. Those healing abutments are made in PEEK, a high-performance biocompatible thermoplastic polymer. They are easily customizable at the office for fulfilling a variety of demands. Thus, there are only four healing abutments for all situations.
Besides that modeling function, they can be prepared (in the mouth or not) for supporting a stock tooth or pressed crown. The greatest advantage of using them as support for temporary prosthesis is the gingival conditioning before selecting the prosthetic component, avoiding, therefore, the change of those intermediate pieces before making the final prosthesis.
The Arcsys system was developed with the objective of fulfilling some of the limitations of the conventional prosthetic components, and, at the same time, to simplify the prosthetic phase and reduce the stock of components that professionals need in their offices.
The system counts on two abutment diameters (3mm and 4.2mm), each one with two possible prosthetic heights (4 or 6mm). All abutments are available in transmucosal heights of 0.5m to 2mm (non-foldable) or 2.5 to 5.5mm (foldable).
For screw-retained prosthesis, Arcsys System offers two types: Mini Abutments and Abutments with transmucosal heights varying from 0.5mm to 2mm (non-foldable) and from 2.5m to 5.5mm (foldable).
The possibility of customization of angulation of up to 20° for components (abutments for screw or cement-retained restorations) with 2.5mm or greater bands does not eliminate the need for reverse planning, but allows for a refinement of the position of the extraction of the prosthetic component. That allows the technician to build infrastructures with the adequate resistance and enough space for the coating material.
This is the great advantage of the Arcsys System in comparison to others available on the market, which only offer two angulations (15°/17° and 30°) for its components, strongly limiting the perfect resolution of cases that require intermediate angulations. Besides, most systems do not offer folded component options for screw-retained single prosthesis, forcing professionals to use cement-retained prosthesis in that case.
Another advantage of the Arcsys System is that the abutments for screw-retained restorations work for single or multiple prostheses, since the copings used for making the infrastructures may be for crown or for bridge. Those copings are available in burn-out CoCr and burn-out versions.
Multifunctional Impression Caps
Once more, thinking of the reduction of stock for the professionals, FGM created multifunctional impression caps also manufactured in PEEK for all its respective prosthetic intermediate pieces. Besides transferring the positioning information to the laboratory, they are used as support for temporary prosthesis and as protectors for those components.
Branemark PI, Adell R, Breine U, Hansson BO, Lindstrom,J Ohlsson A. Intra-osseous Anchorage of dental prostheses I. Experimental Studies. Scandinavian Journal of Plastic Reconstrutive Surgery 1969; 3:81-100.
Branemark PI, Hansson BO, Adell R, Breine U, Lindstrom A, Hallén O, Ohman A. Osseointegrated implants in the treatment of the edentulous jaw. Experience from a 10-year period. Scandinavian Journal of Plastic Reconstrutive Surgery 1977; 16 (suppl).
Garber DA. The esthetic dental implant: letting restoration be the guide. J Am Dent Assoc 1995; 126:319-325.
Volpato CAM, Garbelotto, LGD, Zani, IM, Vasconcelos, DK. Próteses odontológicas: uma visão contemporânea – fundamentos e procedimentos – São Paulo: Santos, 2012