Treatment plan
The surgery was planned with Straumann® Guided Surgery to obtain restoratively ideal implant positioning and the correct angulation of the implant. The surgical planning revealed that the implant had to be placed within the prosthetic envelope and in correct fourth dimension to allow for aesthetic restoration. Therefore, bony perforation and dehiscence were anticipated, and the site had to be grafted. A Straumann® Bone Level Tapered Implant (BLT) was planned to help achieve satisfactory primary stability and minimize bone drilling, due to the tapered shape of the apex of the implant.
A prosthetic template (surgical guide) was prepared beforehand and used for the initial osteotomy.
Surgical procedure
After the administration of local anesthesia, the flap was raised with vertical releasing incisions, and the surgical template was put in place (Figs. 3-4). Next, a Straumann® BLT Implant 4.1 x 14 mm with an RC healing abutment 5x4 mm were placed (Figs. 5-6). Afterwards, the exposed threads of the dental implant were covered with maxgraft® cancellous granules to gain vital bone around the implant (Figs. 7-13). maxgraft® is a processed and freeze-dried allogenic bone substitute with excellent osteoconductive properties that will remodel into native bone.
Accordingly, the site was covered with cerabone® granules 0.5 – 1.0 mm, a slowly resorbable bovine bone substitute, in order to prevent resorption, gain convexity and preserve the long-term aesthetic outcome (Fig. 8). The layering technique in combination with maxgraft® was chosen because ITI guidelines recommend that native bone should ideally cover the exposed implant surface. A periosteal releasing incision was performed before applying the granules in order to ensure that the mucogingival flap could be closed in a tension-free manner with the additional volume of the grafting material (Fig. 9). The shape of the Jason® membrane, a porcine pericardium membrane with a prolonged barrier function, was modified using a template (Fig. 10). The Jason® membrane was cut according to the template extra orally and fixed in place using 3mm titanium pins to achieve maximum stability, which has been linked to predictable guided bone regeneration outcomes (Fig. 11). The GBR was performed using the layering technique, first applying the maxgraft® and then the cerabone® covered with Jason® membrane (Figs. 12-14). Jason® membrane was used to cover the augmentation site to prevent soft tissue cells from proliferating into the site (Fig. 15). The GBR was performed up to the level of the healing abutment, which was also used to tent the membrane. In the authors’ view this method can provide more predictable GBR results. The site was sutured with 5/0 Prolene sutures and left to heal for 12 weeks (Fig. 16). Post-operative instructions verbally and in writing were given to the patient, and sutures were removed two weeks later. After 12 weeks of uneventful healing, the healing abutment was partly visible through the gingiva, and the gum looked healthy (Fig. 17).