Comparison between implants inserted with and without computer planning and custom model coordination.

In the last decade, several systems for computer-planned implantology have been reported. Among them is a system that uses software and a three-dimensional parallelometer able to transfer the implant position from the virtual project to the master model. To verify the effectiveness of this system, a retrospective comparative study has been planned.A series of 300 implants were analyzed. Sixty-six were inserted with computer planning. Several variables related to patient, anatomic site, implant, and surgery were investigated. Implants' failure and peri-implant bone resorption were considered as predictors of clinical outcome. Kaplan-Meier method and Cox regression analysis were then performed to detect those variables statistically associated with the clinical outcome.Implant length and diameter ranged from 10 to 16 mm and from 3.75 to 6.0 mm, respectively. Implants were inserted to replace 66 incisors, 39 canines, 116 premolars, and 79 molars. Mean follow-up was 14 months. Nine implants were lost (survival rate, 97\%), but no differences were detected among the studied variables. On the contrary, lower crestal bone resorption was detected for implants inserted in healed bone and in anterior jaws.Computer-planned and cast model-transferred implantology give good clinical results in survival and success rate. It is a useful technology that should be used in most difficult cases such as totally edentulous patients and reduced crestal bone volume.