Precision and trueness of computer-assisted implant placement using static surgical guides with open and closed sleeves: An in vitro analysis

Objectives: The aim of this in vitro study was to determine accuracy defined by trueness and precision of computer-assisted implant surgery comparing two guided surgery kits designed for either closed sleeves or open sleeves with a lateral window. Material and methods: Each n=20 implants were placed fully guided (sleeve-bone distance of 2 or 4 mm) in identical replicas using a surgical guide with both closed sleeve or an open sleeve, partially guided, or free hand. The achieved implant position was digitized and compared with the planned position. Trueness and precision were determined. The angular deviation was defined as the primary outcome parameter. The means, standard deviation, and 95%-confidence intervals were analyzed statistically with 1-way ANOVA and the Scheffé procedure. Results: The accuracy of guided implant placement using closed and open sleeves was comparable when the sleeve-bone distance was 2 mm. Accuracy decreased when the sleeve-bone distance increased in both fully guided groups, more so in the open than in the closed sleeve group. The least accurate method was the free-hand group. Partially guided implant surgery was more accurate than free-hand placement, but less accurate than the fully guided groups with 2-mm sleeve-bone distance. Conclusions: The closer the sleeve to the bone, the more accurate and precise is computer-assisted implant surgery using a closed system and a system using open sleeves. Partially guided implant surgery using only the static guide for the pilot drill is less accurate than both fully guided approaches, but more accurate than free-hand surgery.