Marco Migliorati1, Sara Drago2, Irene Schiavetti3, Francesco Olivero2, Fabrizio Barberis4, Alberto Lagazzo4, Marco Capurro4, Armando Silvestrini-Biavati2, Stefano Benedicenti5. 1. *Orthodontics Department, Genoa University School of Dentistry, marco.migliorati@unige.it. 2. *Orthodontics Department, Genoa University School of Dentistry. 3. **Section of Biostatistics, Department of Health Sciences (DISSAL), Genoa University. 4. ***Department of Civil, Chemical and Environmental Engineering (DICCA), Genoa University, and. 5. ****Department of Surgical and Diagnostical Integrated Sciences, Genoa University, Italy.
Abstract
OBJECTIVE: To evaluate the primary stability of different shaped miniscrews through the acquisition of data regarding maximum insertion torque, pullout force, and a radiodiagnosic evaluation of bone characteristics. MATERIALS AND METHODS: Sixty fresh porcine bone samples were scanned by computed tomography (CT) and cone-beam computed tomography (CBCT). By means of a dedicated software, CT and CBCT images were analysed to measure the insertion-site cortical thickness, cortical density, and marrow bone density. Sixty miniscrews of 12 different types were implanted with no predrilling pilot hole in the bone samples. Every device was tightened by means of a digital torque screwdriver and torque data were collected. Subsequently, pullout tests were performed. Spearman and Pearson correlations were employed to compare any relationship between continuous variables. RESULTS: Different types of miniscrews did not show statistically significant differences in their torque value (P = 0.595), instead a significant difference was revealed by considering their load measures (P = 0.039). Cortical bone thickness resulted strongly correlated both with value of load (P < 0.001), and modestly with torque measures (P = 0.004). A strong positive correlation was found between CT and CBCT both for cortical density (P < 0.001) and marrow bone density (P < 0.001). CONCLUSION: Bone characteristics play the major role in miniscrews primary stability.
OBJECTIVE: To evaluate the primary stability of different shaped miniscrews through the acquisition of data regarding maximum insertion torque, pullout force, and a radiodiagnosic evaluation of bone characteristics. MATERIALS AND METHODS: Sixty fresh porcine bone samples were scanned by computed tomography (CT) and cone-beam computed tomography (CBCT). By means of a dedicated software, CT and CBCT images were analysed to measure the insertion-site cortical thickness, cortical density, and marrow bone density. Sixty miniscrews of 12 different types were implanted with no predrilling pilot hole in the bone samples. Every device was tightened by means of a digital torque screwdriver and torque data were collected. Subsequently, pullout tests were performed. Spearman and Pearson correlations were employed to compare any relationship between continuous variables. RESULTS: Different types of miniscrews did not show statistically significant differences in their torque value (P = 0.595), instead a significant difference was revealed by considering their load measures (P = 0.039). Cortical bone thickness resulted strongly correlated both with value of load (P < 0.001), and modestly with torque measures (P = 0.004). A strong positive correlation was found between CT and CBCT both for cortical density (P < 0.001) and marrow bone density (P < 0.001). CONCLUSION: Bone characteristics play the major role in miniscrews primary stability.
Authors: Marco Migliorati; Lucia Cevidanes; Giordana Sinfonico; Sara Drago; Domenico Dalessandri; Gaetano Isola; Armando Silvestrini Biavati Journal: Head Face Med Date: 2021-01-15 Impact factor: 2.151