A metal-free solution for restoring natural esthetics

Clinical situation and treatment planning

A 57-year-old female patient presented at our clinic in May 2018. She asked for restoration of her premolar and molar sites after extraction. The teeth had been extracted elsewhere three months (tooth #45) and one year (tooth #46) before her visit (Figs. 1a & b). The radiographic examination showed a single lateral dehiscence defect at site #45 and a fully healed site #46 (Fig. 2). The patient was informed about ceramic implants as an alternative to titanium implants and the NobelPearl™ tapered dental implant system (Nobel Biocare) as a metal-free solution. After a detailed explanation and discussion, the patient decided on this treatment option. The main reason for her decision was the prognosis of less inflammation of the peri-implant tissue with ceramic implants. The disadvantage of less long-term evidence compared with titanium implants was taken into account. After an initial hygiene phase and the periodontal treatment of tooth #47 by root planing, the implant surgery was performed in July 2018.

Surgical and restorative protocols

After cleaning of the alveolar bone, a suitable bone level for implant insertion in site #46 was established and a lateral defect at site #45 was observed (Fig. 3). NobelPearl tapered dental implants of 4.2 mm in diameter and 10.0 mm in length with NobelPearl Inter-X straight abutments were used in the clinical procedure (Fig. 4). Both implants were inserted 0.6 mm supra-crestally at a torque of 30 Ncm. Primary stability was good. The implants were covered with Inter-X cover screws in situ (Fig. 5).

The buccal surface of implant #45 remained within the bone contour (three-wall defect), thus the lateral defect could be easily augmented with deproteinized bovine bone (Bio-Oss®, Geistlich) and a membrane (Bio-Guide®, Geistlich) following the standard clinical procedure (Figs. 6 & 7). After smoothening a periosteal incision, primary wound closure could be achieved. Three months after surgery, the restorative process began (Figs. 8–10) with re-entry by small single roll flaps at each implant site and placement of 3 mm NobelPearl healing abutments. The soft tissue was healthy and keratinized around the healing abutments when open-tray impression taking was performed after two weeks. A monolithic zirconia crown was selected as the prosthetic solution. For stability, and because of the augmentation at site #45, the crowns were splinted.

After removal of the healing abutment (Fig. 11) and try-in of the NobelPearl abutments, the screw channels were sealed with Teflon and the abutments were prepared for cementation (Figs. 12–14). To achieve a tension and bending-free connection between the restorations and the implants, the zirconia restorations were cemented intra-orally to the abutments according to the standard procedure using RelyX Unicem (3M ESPE). Teflon was removed through the screw channel and the entire restoration was removed again as a whole piece. The cement could then be easily removed and the final restorations polished. After this cleaning, the restorations were reinserted and the VICARBO screws were torqued to 25 Ncm according to the guidelines. The screw channels were closed again using Teflon tape (Fig. 15) and finally covered with composite (Figs. 16 & 17). The total treatment time was four months.

Clinical outcomes

The result was beautiful, and the patient was highly satisfied at the one-year follow-up (Figs. 18 & 19). No inflammation or prosthetic problems occurred during the follow-up period. The result in this case was a metal and cement-free, screw-retained and reversible restoration. If problems such as chipping or subsequent colour adjustments were to become obvious, these could be easily corrected and revised—like with titanium implants.