Tooth Replacement in the Maxillary Posterior

Whether implants are placed freehand or with a guide, the use of cone-beam computed tomography (CBCT) imaging can help to improve the accuracy of treatment. There is a significant amount of literature supporting the use of CBCT for implant diagnosis, treatment planning, and surgical guide fabrication. Furthermore, in a June 2012 position statement, the American Academy of Oral and Maxillofacial Radiology recommended that cross-sectional imaging, particularly CBCT, be used for the assessment of all dental implant sites.

Current postgraduate residents in advanced dental training are being introduced to the concept that CBCT is state-of-the-art for implant planning and placement. Although many of the postdoctoral periodontal programs in the United States are providing their residents with training regarding acquiring and interpreting CBCT images as well as training to apply implant planning software, far fewer programs use this technology to make surgical guides for the majority of their implant cases.

This case report demonstrates the favorable outcome of guided implant placement with a surgical guide fabricated using CBCT data and implant planning software. With such a guide, much of the stress of implant placement can be alleviated. Implants can be more ideally placed in restoratively driven positions, vital structures can be avoided, and any guesswork can be eliminated.

A 72-year-old male patient with a nonsignificant medical history desired implant placement in the upper right posterior area. The restorative dentist planned for a three-unit bridge and a single implant crown. After CBCT data were obtained (3D Accuitomo 170, J. Morita), implant planning software (Invivo6, Anatomage) was used to plan three implants (Straumann^® Bone Level Implant, Straumann) for the maxillary right in restoratively driven positions (Figure 1). A surgical guide was then fabricated from that 3D generated planning (Figure 2). Once the patient was anesthetized, a full mucoperiosteal flap was reflected and the guide was seated intraorally, holding the flap out of the surgical field (Figure 3). The osteotomies were performed with a series of drills and corresponding keys (Straumann^® Guided Instruments, Straumann) (Figure 4), which fit into the surgical guide sleeves and provided accurate drill placement to the planned depth from the pilot drill up to the drill of the final required diameter (Figure 5). After all of the osteotomies have been prepared, the guide can be left in place for the implants to be delivered through it, or it can be removed. In this case, once the final site preparations had been completed, the guide was removed (Figure 6), and the implants were placed directly into the osteotomies (Figure 7). Cover screws were then placed, and a posttreatment radiograph was acquired to evaluate the implant placement (Figure 8). After a 4-month healing period, the implants were uncovered, and temporary restorations were placed for a 2-month provisionalization period prior to final restoration (Figures 9 and Figure 10).

John R. Francis, DDS, MS
Clinical Assistant Professor
Department of Surgery
Midwestern University
College of Dental Medicine
Glendale, Arizona