Initial situation

A systemically healthy 37-year-old female patient complaining of discomfort on the left side of the lower jaw presented to the Center of Dental Medicine, University of Zurich. She was seeking a dental treatment that would take less time and cost less money, with a reduced number of surgical interventions. The intraoral examination revealed root caries and a missing crown on tooth 36 (Figs. 1, 2). The radiographic examination showed a root canal therapy with a periapical lesion around the mesial root (Fig. 3). The patient presented with bone type 2 and no anatomical defects. Oral hygiene was good.

Treatment planning

Discussion of the advantages, concerns, and alternative treatment solutions with the patient, followed by collective and collaborative decision-making, was essential for a successful treatment plan that met our patient’s needs.

The patient’s history and expectations were considered, and the decision was made to perform an immediate implant placement with a single crown with cantilever design.

The rationale of the treatment plan and steps included:

• Molar tooth extraction preserving 2-3 root sockets
• Immediate implant placement in the mesial socket
• Use of a TLX implant to ensure the primary stability in the socket walls and optimal soft tissue behavior.
• Filling of gaps and remaining sockets using a xenogeneic graft material
• Use of a healing cap that allows the soft tissue contours to be preserved
• Single crown with cantilever design to facilitate effective oral hygiene

Surgical procedure

The patient underwent local infiltration anesthesia (articaine 4% with epinephrine 1:100,000) and the inferior alveolar left nerve was blocked. An intrasulcular, supracrestal incision around tooth 36 and the neighboring teeth was performed with a Swann Morton blade no. SM67. Following flap elevation, the remaining tooth located on the planned implant site was extracted after sectioning in three fragments (Figs. 4, 5).

A sequential implant site preparation was performed. Figure 6 shows the pilot drill indicator in the mesial root socket, where an immediate implant (Straumann® TLX SP, 4.5 RT; length: 12 mm) was subsequently placed (Fig. 7). The healing cap was selected according to the gingival height (2 mm), and a bone substitute material was placed in the infrabony defects and the distal root socket (Fig. 8).

Adaptive single and cross sutures were placed without the application of a protective membrane on the bone substitute material (Fig. 9).Next, a periapical radiograph confirmed the implant position and healing cap fit (Fig. 10).

The following images show the healing one week post implantation with healthy, stage-appropriate tissues (Fig. 11) and post suture removal (Fig. 12).

Prosthetic procedure

At the 3-month follow-up visit after implant placement, the clinical examination showed an uneventful healing and healthy peri-implant soft tissues. Figures 13 and 14 exhibit the occlusal view with and without the healing cap.

Moreover, the radiographic assessment depicted expected bone remodeling around the implant neck (Fig. 15).

After stable osseointegration was confirmed, digital impressions were taken using a scan body and the TRIOS 3 (3Shape) intraoral scanner. Figures 16 and 17 show the occlusal and vestibular views.

The acquired data was sent to a CADCAM software, and a monolithic implant crown with a distal cantilever was designed (Figs. 18, 19).

The monolithic zirconia implant crown (DD cube ONE ML; 4Y-TZP) was fabricated using a CAM system (Programill PM7), and the screw was tightened following the manufacturer’s instructions (Figs. 20, 21).

Figure 22 shows the final implant crown on the digital implant model (Objet Eden, Stratasys). A titanium base abutment (Variobase®, AH 6 mm, TorcFit™ connection) was used for the screw-retained crown (Figs. 23, 24).

The final implant crown was delivered four months after surgery (Fig. 25). The screw access was sealed with Teflon and composite after torquing to 35 Ncm. (Figs. 26-28). Additionally, a periapical radiograph confirmed stable peri-implant bone tissues (Fig. 29). Finally, oral hygiene instructions were provided to the patient.

Treatment outcomes

The fully tapered implant design of the Straumann® TLX contributed to the success of the immediate implant placement in a molar socket, with optimal primary stability. The advantages of this treatment included the reduced number of surgical interventions, reduced treatment time and treatment costs and easy implant placement in the molar root socket.

Tips from the experts

Immediate implant placement directly into a molar root socket is recommended in the following clinical scenarios:

• Periodontally healthy patients
• Minor or no infection prior to extraction
• When intact socket walls with no or minor dehiscence defects are present
• When under-preparation of the implant site is desired
• To omit guided surgery