Implant placement in the esthetic area: criteria for positioning single and multiple implants

Patient expectations from implant treatment have changed over the years and esthetics plays an important role in defining what is now called success of rehabilitation. Of the many factors that influence the outcome of the rehabilitation, the two main ones are the bone and soft-tissue deficiencies at the intended implant site. Many surgical approaches are described in terms of timing of implant placement and management of regenerative procedures. The aim of this article is to discuss the different implant placement alternatives in the esthetic area, in particular: (i) the timing of implant placement/regenerative procedures/skeletal growth/altered passive eruption; (ii) the correct three-dimensional position of the fixture between the cuspids and in the premolar area; (iii) multiple missing teeth in the esthetic area with single tooth/pontic or cantilevered options/prosthetic compensation; (iv) placement of implants into infected sites; and (v) the influence of abutment and crown morphology on implant position. Combining our long-standing clinical experience and the pertinent literature, the following conclusions can be drawn: Immediate implant placement can be a successful procedure in terms of esthetics but it is technique sensitive and requires an experienced team. Immediate placement is less traumatic to the patient as fewer surgical procedures are involved and patients tend to prefer this clinical approach with regards to quality of life. The diagnostic phase is of utmost importance, with not only bone and soft tissue deficiencies being addressed but also: skeletal growth, dental/implant soft tissue parameters such as altered passive eruption and the morphology of the roots adjacent to the edentulous area. Post-extraction immediate loading is feasible in infected sites. The correct position of the fixture should follow widely accepted guidelines but the abutment morphologies play a role in the vestibular/palatal position of the implant. The long axis of the implant, aiming at the incisal edge of the future restorations, is the most appropriate implant position when a shoulder-less abutment is used and allows a restorative crown morphology with a cervical contour resembling a natural tooth. The use of a shoulder-less abutment gives more space for the tissue to grow compared with the traditional abutment with shoulder finish line.