In vitro examination of different disinfection methods in the reuse of mini screws

Objectives: The aim of this study is to present a new chemical cleaning method for the reuse of mini screws in orthodontic treatment and to compare its applicability, effectiveness, and clinical application convenience with a conventional method. Methods: 80 mini screws were randomly selected and divided into 4 groups. The mini screws located in first three of the study groups were applied in bone blocks and then removed. Subsequently, the first group (AG) was cleaned with distilled water, the second group (OG) with 37% orthophosphoric acid and 5.25% NaOCl, the third group (HG) with a mixture of 9% etidronic acid and 2.5% NaOCl. The fourth (control) group (KG) did not receive any treatment. 10 randomly selected mini screws from the groups were inserted into the bone blocks by measuring the maximum insertion torque; were extracted by measuring the maximum extracting torque. Remaining 10 mini screws in each group were examined by SEM/EDS; followed by placement in bone blocks and subjected to the horizontal force resistance test to investigate their mechanical resistance. Results: For mechanical testing, the second and third groups showed similar values to those in control. There was no difference between the groups in terms of horizontal force resistance (p.05). SEM evaluation revealed that the tested chemical cleaning is effective for cleaning prior to the second application of mini screws. Conclusion: It is determined that the tested chemical cleaning process is effective in the second use of mini screws. Hence, the chemical cleaning method, which we created is as effective as the other chemical cleaning method and can take its place in clinical practice by saving time compared to the other method.