A descriptive study on retrieved non-threaded and threaded implant designs

Objectives: In the light microscope compare the amount of bone saucerization for non‐threaded cylindrical and threaded implant designs in retrieved samples from patients. Material and method: Consecutively received retrieved oral implants from 117 patients, whereof 85 non‐threaded cylindrical and 85 Brånemark implants, have been included in the study. For 75 non‐threaded cylindrical and 46 Brånemark implants was the entire implant length available for calculation. Undecalcified ground sections were investigated in the light microscope with calculation of percentage of implant length coronal to the first bone–implant contact and percentage of bone to implant contact. Results: Mean value for implant length coronal to first bone–implant contact was 65%, standard error of the mean (SEM) 3 (range 0–100%), for non‐threaded cylindrical implants and 43%, SEM 6 (range 0–100%) for Brånemark implants. Mean values of bone contact along the entire implant length was 23%, SEM 2 (range 0–65%), for the non‐threaded cylindrical implants and 33%, SEM 5 (range 0–93%) for the Brånemark implants. Conclusion: Within the limitations of this retrospective, retrieval study non‐threaded cylindrical implants demonstrated a greater bone saucerization when evaluated in the light microscope.