Panoramic images versus three-dimensional planning software for oral implant planning in atrophied posterior maxillary: a clinical radiological study.

PURPOSE: The objectives of this radiographic study were to determine to what degree the available residual bone area for implant placement was underestimated on panoramic radiographs (by comparison with multislice computed tomography CT/cone beam CT images combined with planning software) and to what degree the rate of severely resorbed posterior maxillae requiring sinus lift was overestimated on panoramic radiographs (by comparison with planning software in combination with strategic implant placement). MATERIALS AND METHODS: During a 2-year period, every patient who presented for the placement of implants in the posterior maxilla was examined by three practitioners to discuss the treatment plan. When two to three practitioners indicated a sinus lift with creation of a lateral window, a CT scan was performed and examined using dedicated three-dimensional software by a clinician familiar with the Computer Assisted Design/ Computer Assisted Manufacturing (CAD/CAM) implant placement protocol. For each tooth to be replaced, the presence of anatomical features such as anterior or posterior wall, palatal curvature, and septa were examined in view of the placement of an 8-mm or longer implant. RESULTS: One hundred one patients were studied in this case series for the treatment of 135 edentulous spans accounting for 301 missing teeth. After examination of the CT data on the three-dimensional software, 202 teeth (67.1%) could be replaced using a CAD/CAM procedure; 60.7% of the edentulous spans could be completely repaired by a crown or bridge supported by implants. In addition, 67.3% of edentulism with no teeth posterior to the span could be completely repaired using a fixed prosthesis supported by implants. CONCLUSION: This radiological study demonstrates that the use of a panoramic exam for oral implant planning in severely resorbed maxillae overestimates the need for a sinus augmentation procedure when compared with the use of both three-dimensional planning software and strategic implant placement on small remaining bone volume.

Placement of posterior maxillary implants in partially edentulous patients with severe bone deficiency using CAD/CAM guidance to avoid sinus grafting: a clinical report of procedure.

PURPOSE: To provide a detailed presentation of computer-aided design/computer-assisted manufacture guidance in severely resorbed posterior maxillae to place implants in a very limited amount of bone, thus avoiding sinus grafting. MATERIALS AND METHODS: Based on computerized tomography (CT) axial images, implant positions are planned using imaging software. A surgical template is fabricated and drilled with a numerically controlled machine to transfer the planned positions to bone with high accuracy. To avoid sinus grafting, implants can be planned in the anterior or posterior wall and in the septa of the sinus as well as in the palatal curvature. Recipient site preparation is done transgingivally with a drill or with a dedicated bone spreader to increase the amount of bone when necessary. RESULTS: Fifteen resorbed posterior maxillae were treated with a fixed prosthesis supported by a combination of 42 upright and tilted implants. In all cases, implants were placed as planned. Seventeen implants were tilted at a 20- to 35-degree angle with the line perpendicular to the axial CT images. Seven implants were placed in the palatal curvature, 11 implants were close to the anterior wall, and two of them in combination with the palatal curvature. Only one implant was placed close to the posterior wall and two were placed in septa. All patients attended scheduled follow-up visits. During the 4-year observation period, no complications were recorded, no implants were lost, and there was no infection or inflammation. CONCLUSION: This proof-of-concept study suggests that the use of an image-guided system associated with bone spreading for oral implant placement in the atrophic posterior maxilla can be an alternative to sinus grafting.

An image-guided system-drilled surgical template and trephine guide pin to make treatment of completely edentulous patients easier: a clinical report on immediate loading.

PURPOSE: An image-guided system has been developed to drill a conventional surgical guide following a preoperative three-dimensional plan for accurate placement of implant on bone. The aim of this study is to illustrate how this system facilitates treatment of completely edentulous patients by modifying both surgical and prosthetic protocols, thereby making flapless surgery possible as well as the preparation of the transitional prosthesis before surgery. MATERIALS AND METHODS: This system was tested on 10 consecutive patients, placing all planned implants without raising the mucoperiosteal flap and with the connection of all implants to pre-angulated abutments. RESULTS: A 1-year follow-up demonstrated stable and properly functioning prostheses in all cases. CONCLUSIONS: This technique can be expected to flourish because implantology makes the highest demands on comfort, precision, and safety.