CAD/CAM international magazine of digital dentistry

Insufficient hard and soft tissue may eventu- ally lead to the implant restoration not inte- grating aesthetically with the existing dentition. Often, a reconstruction of the interdental papilla is not possible, and the contour of the marginal gingiva cannot be shaped harmoniously. A high smile line does not allow any compromises at all in soft-tissue aesthetics, since the colour and contour of the peri-implant mucosa must cor- respond to the soft tissue in the region of the neighbouring natural teeth. Careful planning, considering all relevant clinical and patient- related parameters, is therefore very important for achieving a predictable and aesthetically satisfactory treatment result in the implant re- storation of a single tooth. In a single-tooth replacement in the maxilla following traumatic anterior tooth loss, the prac- titionerfacestheproblemofareducedamountof hard and soft tissue. Frequently, portions of the bony alveolar ridge near the tooth have been lost owing to trauma or natural resorption processes. Carefulselectionofthegraftingtechniqueand implants with an osteoconductive surface makes treatmentsuccesspredictableintermsofimplant stability and aesthetics. Along with free connec- tive-tissue grafts and guided bone regeneration using autogenous or xenogeneic bone materials, piezoelectric bone splitting or bone spreading techniques can be used for reconstruction. Piezosurgery has been established as a suc- cessfultechniqueinavarietyofdentaldisciplines over the last ten years. Thanks to the adjustable ultrasound working frequency, different tissue types can be treated selectively without the risk of injury. With its narrow 60 to 200 µm width, thefrictionlessandvibration-freesectioningfalls significantly below the incision width produced by using conventional instruments. Today, bone splitting is considered to be a safe and simple method for the expansion of bone tissue. In a systematic review, success rates of 95 to 100 per cent were reported using this tech- nique in combination with a single- or two-stage approach. The final consideration in planning is the se- lection of the appropriate implant type: healing and osseous integration are markedly dependent on the chemical composition, loading, rough- ness and the morphology of the surface of the implant. Thanks to its good bone–implant interface characteristics and the associated in- creasedprimarystability,theXiVEimplantsystem (DENTSPLY Implants) can also be placed securely and predictably into bone where the site is weak and into areas of low bone density. Long-term results demonstrate a high survival rate for XiVE implants, which can be traced back to the macro- and micro-design of the implant system. _Case report Anamnesis A 23-year-old, healthy patient presented at the practice requesting the replacement of tooth #21. The tooth had already been endodontically restored following an anterior tooth trauma in the patient's childhood. Despite multiple revi- sions, the apical periodontitis had not healed. The tooth had been extracted and, as a result, there was severe bone resorption. The gap was initially restored with an interim prosthesis. Orthodontic treatment followed some years after the extrac- tion, during which the gap in region #21 also had to be widened for the implant restoration. Clinically and radiologically, a caries- and fill- ing-free dentition was evident, with orthodon- tic brackets and archwires in the maxilla and mandible. There was evidence of severe buccal resorption of the alveolar process in region #21 (Fig. 1). 3-Dradiologicalanalysis A 3-D analysis of the bony structures and the position of the nerve and the vascular bundles was performed for the treatment planning. Three- dimensionalassessmentplaysacentralroleinthe Fig. 4_The mucoperiosteal flap was prepared and raised. The periosteum was carefully detached from the bone in this process. Fig. 5_At the implant site, the mark placed using a round drill was enlarged with a pilot hole and prepared using the Piezotome, with two short vestibular incisions and a long horizontal incision at a 90 degree angle. Fig. 6_The alveolar bone was gradually expanded horizontally. Fig. 7_The implant site was prepared with the XiVE twist drill. I 17 case report _ implant prosthetic restoration I CAD/CAM 4_2012 Fig. 7Fig. 6 Fig. 5Fig. 4