How to: Use a retentive prosthetic multisystem

By now, most patients and dentists are well aware of the benefits of implants in terms of improved long-term oral health, as well as an improved quality of life for patients. Because of this, there have been many advances in recent years by manufacturers hoping to deliver easier, longer-lasting and more predictable implant outcomes.

One new such advancement has recently come about in the area of low profile castable, and direct implant overdenture attachments. In an effort to deliver a system that produces full functionality and ease of use, while working with any kind of implant-supported prosthetics, Rhein 83 USA Inc. developed OT Equator® profile, the newest line of low profile castable, and direct implant overdenture attachments.

The company redesigned its classic OT Cap sphere by removing the upper and lower radius sections of the attachment leaving only the central or Equator portion, which provides maximum retention with minimum height. With a low vertical profile of 2.1 mm and diameter of 4.4 mm, OT Equator is the smallest attachment system on the market.

This system offers multiple solutions for overdenture treatment planning where inter-occlusal space limitations are indicated. It is available in two versions- Castable and Prefabricated Titanium abutments-and is compatible with any implant brand on the market; cuff heights are available from 1 mm to 7 mm.

Female caps range in four levels of retention, and are easy to process by the dental laboratory, or during chairside procedures in the dental office.

Equator’s specially designed stainless steel housings gives the female caps added stability and retention in the acrylic.

OT Equator castable low profile attachments are indicated for root- retained post and core overdentures (Fig. 1) and also positioned on implant-supported cast bar super structures (Fig. 2).

For best results during the casting procedure, it is recommended to use an alloy with a minimum Vickers Hardness of 240.

Implant abutments are gold because of a TiN (Titanium Nitride) coating that gives Equator an extremely smooth 1600 Vickers surface and extends the life of the female cap.

Clinical case

01. Screw abutments into the implants and take an impression using the transfers (Fig. 3).

02. During the laboratory procedure attachment analogs will be placed into the stone model for proper position (Fig. 4).

03. Castable connectors are used in the wax up design, and reinforcement pins are positioned giving extra support to the denture teeth. Check position with silicone lab putty (Fig. 5).

04. Once casting is completed, proceed with the placement of the stainless steel housings using denture resin. After curing the housings in position (Fig. 6), select the proper retentive cap and snap into the housing using the OT Equator insertion tool. The completed denture is ready for insertion (Fig. 7).

05. The diversification of OT Equator is represented by the Seeger Ring System. These components make it easy to set connecting bars. Transfer for impression is inserted into the implant analog. Using OT Bar Multiuse castable components, a passive bar is fabricated to link the three implants with the Elastic Seeger System (Fig. 8).

06. The over-structure is waxed up together with OT Bar and Cast using the same block (Fig. 9).

07. Screw the OT Equator abutments directly into the implant fixtures (Fig. 10).

08. Bar will lock in place over the implants by using the Elastic Seeger (for passive connection) then the Titanium screw is used to securely lock the implants (Fig. 11).

Closing thought

Fig. 12 illustrates the finished bar in place after the procedure has been completed. Characteristics of the OT Equator profile system include the smallest attachment on the market with retentive modulating faculties. The attachment is designed to produce to the prosthesis a superior stability in procedures where two implants are used to obtain a prosthesical retention. Plus, it provides the possibility to create a passive union between the two implants in the case in which a bar connection is needed, (ex: direct load), avoiding fusion problems owed to fusion or impression taking.