Introduction

Driven by patient demands and increased clinical evidence, recent developments in implant dentistry have seen a pronounced trend towards early and immediate procedures⁷. This trend has been especially pronounced for full-arch rehabilitations that prevent patients from being exposed to a long period of edentulism^8–10.

One of the clinically most relevant factors for the prognosis of implant success of immediate procedures is primary implant stability^11,12. This factor becomes even more important in patients with compromised bone quality or quantity¹³. The novel BLX implant with its self-tapping tapered implant body and its protruding thread geometry represents one of the most promising tools to help clinicians achieve a high level of bone engagement and immediate primary stability¹⁴.

Although recent research suggests good clinical success rates for full-arch restorations even in periodontally compromised patients, a combination of optimized primary stability, surgical flexibility and long-term tissue level stability could be highly desirable^15,16.

The following case report describes the procedure and 1 year follow-up of a full-arch restoration with the novel Straumann® TLX Implant System, using a straightforward direct-to-implant restorative concept. The novel implant system combines the endosteal design of the BLX implant system for optimal primary stability, with an emergence profile that has proven to deliver successful long-term soft tissue stability. This qualifies the system for immediate procedures in situations with an enhanced hygiene requirement, for example in the illustrated treatment of a periodontally compromised patient.

Initial situation

A 49-year-old patient presented in our clinic after a prolonged period without dental check-ups and with a complaint of unsatisfactory esthetics and discomfort while eating due to teeth mobility (Fig. 1). The patient reported that he was a smoker and had limited time available because of his professional activity. Oral examination revealed severe generalized periodontitis (stage III to IV) associated with poor oral hygiene, as evidenced by the presence of advanced gingival recessions, exposed root surfaces, abnormally pale gingival color, loss of interdental papillae and Miller class I tooth mobility¹⁷. The patient was in good general health and had no absolute contraindications for implant treatment.

Diagnostic cone beam computed tomography (CBCT) (Fig. 2) revealed pronounced horizontal bone loss in the maxilla with vertical intraosseous components¹⁸. The maxilla also displayed a wide range of conditions with uncertain treatment prognosis, including a likely furcation involvement of the second molar (potentially class III¹⁹) in position 18, apical radiolucency indicating a cyst on the palatal root of the first molar in position 17, severely advanced horizontal bone loss on teeth 25 and 27 with potential oroantral communication. The mandible also displayed horizontal bone loss, but at a less advanced stage, allowing a conservative treatment approach with adequate prognosis except for tooth positions 36 and 37, which were considered hopeless.

Together with the patient, the decision for an immediate maxillary full-arch restoration was taken based on the patient’s wish for an immediate, cost-effective and comprehensive treatment solution.

Treatment planning

Differential diagnostic evaluation according to Bedrossian et al. indicated a normal smile line (Fig. 1), appropriate occlusal vertical dimensions (Fig. 4) and the presence of teeth-only defects allowing for a white bridge²⁰. Considering the advanced atrophic state of the posterior maxilla and the missing osseous structure beneath the sinus, the restorative concept was defined as a first molar to first molar white zirconia framework supported by four implants (Fig. 3). Inclination of the posterior implants engaging with the anterior sinus walls allowed for an increased A/P spread avoiding cantilevers and augmentation procedures²¹.

Planning of the restorative phase specifically considered the periodontal preconditions of the patient implying a greater need for hygiene maintenance and long-term biologic tissue stability. The novel TLX implant represented the ideal tool to meet these requirements, combined with the ability to achieve an optimal level of primary stability as part of the immediate protocol. Figure 3 illustrates the detailed planning of the implant restoration based on four Ø 3.75 x 12 mm, TLX Roxolid® SLActive® Implants in coDiagnostiX® in relation to the existing dentition as reference for the prosthetic restoration, as well as the corresponding surgical guide. .

With regards to the prosthetic planning, a cost-effective and straightforward design of the immediate and final prosthetic restoration based on a direct-to-implant concept was feasible. This specific concept further required the divergence between adjacent implants to be restricted to less than 40° to allow for a passive fit of the abutments on the implant base (Fig. 3). As evidenced by the preliminary cast in figure 4, the prosthetic planning further included the correction of a moderate class 2 malocclusion, increasing the vertical dimension and the available crown height space for the restoration.

The surgical procedure was carried out under general sedation in combination with local infiltration anesthesia, and started with minimally invasive tooth removal after an intrasulcular incision (Fig. 5). As part of a strategic tooth extraction protocol, the central incisors, cuspids and the second molar in position 17 were temporarily kept in situ as a precise retention guide²².

Figure 6 illustrates the sequence of osteotomy preparation, guided drilling and implant placement in position 12. Osteotomies were prepared by single guided pilot drilling using VeloDrills™ with a diameter of 2.2 mm and to a depth of 14 mm, ensuring flexibility with regards to implant placement level. As evidenced, anterior implant osteotomies were prepared palatally to the extracted class I sagittal root position for engagement with palatal cortical bone, and in order to reduce any risks for vestibular fenestration. Following verification of correct depth and angulation using alignment pins, TLX implants were placed by hand. Excellent engagement and primary stability for immediate loading of all implants was achieved, as verified by the Straumann® ratchet and torque control device, with insertion torques consistently displaying values above 35 Ncm.

Figure 7 shows the TLX implant with the characteristic self-tapping tapered endosteal part and protruding thread geometry for bone engagement and the elongated machined collar at tissue level for supracrestal positioning of the implant abutment interface.

Prosthetic procedure

The immediate temporary restoration was prepared using conventional laboratory techniques with an open-tray impression. TLX impression posts were mounted on the implants, followed by minimally invasive removal of residual teeth, suturing and fixing of any loose soft tissue margins. Impression posts were then splinted to prevent any distortions during impression taking using dental floss and flowable acrylic (Fig. 8).

Open-tray impressions were produced using a combination of light- and heavy-bodied impression materials. A transparent removal prosthesis was used to register the occlusion and implant prosthetic relation in the sedated patient (Fig. 9).

An immediate provisional hybrid prosthesis was prepared by our associated laboratory and delivered to the patient on the day of surgery (Fig. 10). The provisional concept was specifically realized using a direct-to-implant restoration with non-engaging titanium copings (TorcFit™ connection). The prosthetic framework was cross-arch splinted with a welded bar, resulting in a good immediate passive fit as confirmed by the post-surgical panoramic radiograph.

The final restoration, consisting of a screw-retained zirconia bridge based on Variobase® for Bridge/Bar abutments, was prepared 6 months post-surgery (Fig. 12). Prosthetic planning was based on the existing provisional after bite registration and impression of the soft tissue contours interfacing the pontic sites of the framework using a light-bodied impression material (Fig. 11).

Treatment outcomes

As indicated by the photographs after delivery of the final prosthesis 6 months post-surgery, very satisfactory results with regards to esthetics, functional occlusion and soft-tissue integration were obtained (Fig. 13). Soft tissue conditions around the implants at the 6 month follow-up were healthy and stable, and did not show any sign of inflammation. Remarkably good soft tissue healing was noted around all implants. The overall healthy state of the gingival soft tissues correlated well with the very satisfactory esthetic conditions and healthy coloration of the buccal soft tissues. The 1-year follow-up radiograph further confirmed stable osseointegration of all implants..

The patients did not require any appreciable adaptation periods for the temporary or final restorations. It was particularly noticeable that the patient displayed a marked and distinct change in his behavior and appearance at the follow-up appointment, potentially associated with improved confidence and self-esteem (Fig. 14). The patient reported finding it easy to maintain oral hygiene using a microbrush and a water flosser, which was confirmed by the overall good peri-implant tissue health.

Conclusion

This case report describes the immediate full-arch restoration of a periodontal patient with failing dentition. In this case, the Straumann® TLX Implant System provided an ideal solution to achieve a high degree of primary stability combined with the option to maintain hygiene. In addition, the use of the Straumann® TLX Implant System allowed an effective direct-to-implant restorative concept to be realized.

Acknowledgements

I would like to thank Dr Grégory Camaleonte and the laboratory Ruocco for their help and expertise in designing and fabricating the prosthetic bridges, as well as Alex Ostashko, Stefano Besio and Sébastien Barrière from Straumann.