Clinical accuracy of partially guided implant placement in edentulous patients: A computed tomography-based retrospective study.

OBJECTIVES: This retrospective study was intended to evaluate the clinical accuracy of partially guided template in guiding implant placement in edentulous patients. METHODS: A total of 120 implants were placed in 24 patients with at least one completely edentulous arch with a partially guided system. Based on CBCT data, a repeatable method was used to measure linear and angular deviations of implants at 3D level in Mimics medical software. The influence of supporting tissue and implant region on the accuracy was assessed, followed by the evaluation of direction of linear deviations in biologically vital areas. RESULTS: Linear deviations of all implants were 1.91 +/- 0.68 mm, 1.47 +/- 0.68 mm, and 1.02 +/- 0.69 mm at apical, apical lateral, and apical vertical levels. When at the cervical, cervical lateral, and cervical vertical levels, the linear deviations were 1.53 +/- 0.65 mm, 0.98 +/- 0.53 mm, and 1.01 +/- 0.69 mm, respectively. Angular deviation of all implants was 7.14 +/- 3.41 degrees . Implants guided by mucosa + tooth-supported templates showed higher linear deviations at apical vertical level (1.21 +/- 0.72 mm vs. 0.86 +/- 0.63 mm, p < .05) and cervical vertical level (1.18 +/- 0.72 mm vs. 0.87 +/- 0.63 mm, p < .05) than mucosa-supported templates, and implants in maxilla were found higher angular deviation than mandible (7.89 +/- 3.61 degrees vs. 6.29 +/- 2.97 degrees , p < .05). CONCLUSIONS: The partially guided template served as clinically viable surgical assistance in implant placement in edentulous patients. When using mucosa + tooth-supported template or placing implants in maxilla, more caution was required, especially in biologically vital areas.