The best of both worlds

The use of prefabricated implant abutments offers dental laboratories, their dentists and their patients many benefits. These include the availability of a variety of prefabricated abutment sizes and angulations, as well as the convenience of prepackaged impression analogs and copings.

Recently introduced prefabricated abutments, such as the Straumann® Anatomic IPS e.max® Abutment, which was developed through a partnership between Ivoclar Vivadent and Straumann, provide exceptional esthetics and performance. The anatomically shaped, bone-level Straumann Anatomic IPS e.max zirconium oxide abutment demonstrates high strength and an exceptional fit that requires little adjustment. As a result, users can deliver the best possible esthetic outcomes to their patients.

A horizontal offset, a significant design feature of the Straumann Anatomic IPS e.max Abutment, keeps the micro-gap away from the bone. The SLActive surface of the abutment creates osseoconductivity, and the cross-fit connection of the implant ensures a precise and secure fit. Additionally, the cross-fit connection of the Straumann bone level implant provides stability through deep conical connections and proprietary grooves. As a result, there is a clear path of insertion for a consistently predictable fit.

Case presentation

At the dentist’s office, tooth Nos. 6 through 9 and tooth No. 11 were prepared for IPS e.max lithium disilicate crowns and veneers. A closed tray impression post (Straumann RC) was hand tightened to implant No. 7 (Straumann RC) using the SCS screwdriver. A full-arch impression was taken (Fig. A).

Laboratory protocol

01 A soft-tissue model of the implant site was fabricated by applying a soft-tissue material (Gingitech, Ivoclar Vivadent) around the impression post (Fig. B). Care was taken to extend the tissue material just past the impression post/analog interface while keeping the material away from margins of adjacent preparations. The impression was poured with ­resin-fortified die stone (ResinRock Ivory, Whip Mix).

02 The model was sectioned, trimmed and mounted on an articulator (Stratos 200, Ivoclar Vivadent) for the crown and implant abutment fabrication process (Fig. C). Plastic abutments from the Straumann CrossFit PLAN set were tried on the model to determine the correct diameter, gingival height, abutment height and angulation of the Straumann Anatomic IPS e.max Abutment (Fig. D). The many options available made the selection process fast and easy, with minimal ­adjustments to the final abutment.

03 In this case, a gingival height of 3.5 mm and 15° angled abutment was ordered from the manufacturer (Fig. E). The abutment received ­required very little adjustment to proceed with the case. However, any adjustment to a Straumann Anatomic IPS e.max Abutment must be performed with careful consideration to not overheat the abutment. A diamond bur (Zir-Cut, Axis Dental) was used with a highspeed (300,000 rpm) handpiece (NSK Presto Aqua), light pressure, and plenty of water irrigation to keep the abutment cool (Fig. F). After minor adjustments to the abutment, the case was ready for full-contour waxup.

04 The case was waxed up to full final contours with gray sculpturing wax (Yeti Thowax), and the margins were sealed with bordeaux wax (Yeti Thowax Underlining Wax) (Fig. G). The full-contour waxup was then invested and pressed in lithium disilicate. The canines Nos. 6 and 11 were pressed with an HTB1 ingot, while incisors Nos. 7 through 10 were pressed with LTB1. The pressed units were divested and placed in an ultrasonic cleaner submersed in IPS e.max Press Invex Liquid for 20 minutes. Each unit was then sandblasted with 50-micron aluminous oxide at 2-bar pressure to remove the reaction layer.

05 The sprues were ground off, and each unit was individually seated on the working model (Fig. H). The incisal third of the incisors was then cut back for internal staining and porcelain application. Internal staining was achieved using a combination of IPS e.max Ceram shade paste I2, IPS Empress Universal Stain grey, and IPS Empress Universal Stain vanilla (Fig. I). The stain was fired at 770°C.

06 Once the stain was fired, an internal mammelon porcelain buildup was completed using IPS e.max Ceram porcelains MM light and OE4 (Fig. J). The porcelain was fired at 750°C. The final contours of the incisors were then built in IPS e.max Ceram ­translucent porcelains TI 1 and OE 1 (Fig. K).

07 The restorations were fired again at 750°C. Each restoration was adjusted to final contours in the bisque stage, with the proper proportions, line angles and anatomy evaluated (Fig. L). Canines Nos. 6 and 11 were stained using IPS Empress Universal Stain shade B1 to match the incisors (Fig. M). The stain was fired at 770°C.

08 The restorations were glazed using IPS e.max Ceram Fluorescent Glaze Paste (Fig. N). The monolithic canines were fired at 770°C, while the layered incisors were fired at 725°C. The glazed surfaces were polished with first a Pink Dialite Wheel (Brasseler USA), then with Diashine “fine” polishing paste (VH Technologies).

09 The restorations were cleaned, dried and acid etched with IPS Ceramic Etching Gel. The final restorations exhibited lifelike contours, translucency and texture (Fig. O).

Conclusion

The Straumann Anatomic IPS e.max Abutment is a new and convenient tool for dental laboratory technicians to add to their armamentarium. With a combination of features that enable the creation of lifelike esthetic results and soft-tissue contouring that can be appreciated by dentists and patients alike, the IPS e.max Abutment rivals the shape and esthetic value of a custom abutment, without the need for costly equipment.