Repeatability and precision are major factors which have an influence on final implant treatment results. The aim of this study was to evaluate the repeatability of freehand implant procedures assisted with special plastic sleeves which are placed on the drill to guarantee the proper mesiodistal distance from the landmark's surface. Patient data required for implant treatment, including images of mandibles from CBCT scans and virtual models of soft tissues and teeth, were used to prepare complete virtual models of patient clinical conditions. The models were saved as STL files and 3D printed in five copies. Drilling procedures were done at positions 37, 46 and 47. Each model was scanned with pins in the osteotomies and compared using digital aligning of the models' surfaces. The average deviation was -1.38 ± 1.4 mm. Average deviations on guide pins placed at position 37 were -0.46 ± 0.59 mm, at position 46 were -1.46 ± 0.88 mm (landmark's surface of both: distal tooth's surface), and at position 47 were the highest: -2.69 ± 1.62 mm (landmark's surface: surface of plastic sleeve). The following conclusion was drawn: Using universal plastic sleeves could improve implant procedure precision especially in the case of partially edentulous patients.
Keywords: implantology; precision; repeatability.