Prosthetic rehabilitation of hyperbolic neck transmucosal implant using a digital workflow

OBJECTIVES New approaches for implant placement and new devices for prosthetic rehabilitation techniques are being developed to simplify both surgical and prosthetic phases and to obtain a predictable outcome. The purpose of this clinical case is to describe the advantages and limitations of a prosthetic digital workflow in presence of a single-tooth implant rehabilitation in the esthetic zone (anterior maxilla) using two-piece implant. MATERIALS AND METHODS A patient with a compromised upper right incisor, characterized by severe mobility, root resorption and chronic periapical lesion, underwent an atraumatic tooth extraction. Due to the absence of acute infection, immediate implant placement was scheduled. A two-piece implant was placed with the hyperbolic neck exposed approx. 1 mm above tissue levels (transmucosal placement). A Maryland Bridge restoration was designed before surgery through the acquisition of digital models using a digital intraoral scanner. The Maryland Bridge was cemented using adhesive system and dual cure cement. The restoration was used as temporary rehabilitation until the impression procedures. The prosthetic phase was performed after 3 months from implant insertion. A digital workflow was used. A scan body was placed directly on the transmucosal implant neck without the need for a secondary surgery. A digital impression was acquired using the intraoral scanner, converted into an .stl file and sent to the dental laboratory. Exocad software was used to prepare the customized abutment, the temporary crown and the definitive restoration from the 3D printed models obtained from digital impression. The provisional resin crown was designed according to the Biologically Oriented Preparation Technique (BOPT). The finishing line ended at the implant hyperbolic with a moderate compression of peri-implant soft tissues. The crown was maintained for 21 days. Then definitive zirconium-ceramic crown was cemented with a polycarboxylate cement. RESULTS No complications were observed during the follow-up. Soft tissue adaptation to the hyperbolic neck was observed, with high stability up to the 18-month. CONCLUSIONS The use of a two-piece implant placed with a transmucosal technique and associated with a digital prosthetic workflow allowed an optimal rehabilitation in a highly aesthetic area with a minimally invasive approach. CLINICAL SIGNIFICANCE The combined use of a minimally invasive surgical technique with transmucosal approach represents the first step of the proposed protocol. The healing phase guided by BOPT technique concepts and the use of intraoral scanners play a 3D biological approach in the evaluation of tissue morphology. The development of a fully digital workflow is possible and increases the predictability of clinical cases where aesthetic results is an important requisite. Digital impression technique with intraoral scanner can be considered particularly useful in association with implants placed transmucosal.