The Effect of Insertion Torque on the Clinical Outcome of Single Implants: A Randomized Clinical Trial Antonio Barone, DDS, PhD, MSc;* † Fortunato Alfonsi, DDS; ‡ Giacomo Derchi, DDS, PhD, MSc; ‡§ Paolo Tonelli, MD, DDS; ¶ Paolo Toti, BSc, DDS; ‡§ Saverio Marchionni, DDS; ‡§ Ugo Covani, MD, DDS** ††‡‡§§ ABSTRACT Background: The insertion torque value has been extensively used as an indicator for implant primary stability, which is considered a determining parameter for the implants success. Purpose: The primary goal of the present randomized clinical trial was to evaluate and compare the clinical outcome for implants placed with high insertion torque (between 50 Ncm and 100 Ncm) and regular insertion torque (within 50 Ncm) in healed ridges. Materials and Methods: Partially edentulous patients, missing one or more mandibular or maxillary teeth, having an adequate amount of bone, requiring implant placement, were randomized to receive Blossom CT implants with regular insertion torque (<50 Ncm) or CT implants with high insertion torque (350 Ncm). Implants were left to heal submerged for 3 months. Implants were restored with individualized abutments and cemented metal-ceramic crowns. Acquired measurements were: insertion torque values (IT), thickness of buccal bone plate after implant osteotomy preparation (BBT), marginal bone level (MBL), and facial soft tissue level (FST). All patients were followed 12 months after implant placement. Results: One hundred sixteen implants were placed in one hundred sixteen patients and enrolled for the study. Fifty-eight implants were randomly allocated in regular-IT and high-IT groups with a mean insertion torque ranging from 20 Ncm to 50 Ncm and from 50 Ncm to 100 Ncm, respectively. Three implants failed, and another five implants showed at the 12-month evaluation a marginal bone loss (ΔMBL) greater than 1.5 mm, being considered unsuccessful. Conclusions: The findings suggested that implants inserted with high-IT (350 Ncm) in healed bone ridges showed more peri-implant bone remodeling and buccal soft tissue recession than implants inserted with a regular-IT (<50 Ncm). Moreover, sites with a thick buccal bone wall (31 mm) – after implant osteotomy site preparation – seemed to be less prone to buccal soft tissue recession after 12 months than sites with a thin buccal bone wall (<1 mm). KEY WORDS: delayed implants, delayed restored implant, insertion torque, marginal bone resorption, soft tissue recession INTRODUCTION The use of dental implants to replace missing teeth has become a safe treatment modality over the last decades. 1 Primary implant stability is considered one of the key clinical factors that affects the outcome of implant treatment. 2,3 The implant primary stability was commonly related to insertion torque during implant placement; moreover, several studies had suggested that insertion torque values in the range of 25–45 Ncm could prevent adverse micro-movements (threshold level between 50 *Adjunct professor, § research fellow, **full professor, †† chairman, Department of Surgical, Medical, Molecular and Critical Area Pathol- ogy, University of Pisa, Pisa, Italy; † adjunct professor, ‡ research fellow, ‡‡ full professor, §§ chairman, Tuscan Dental Institute, Versilia General Hospital, Lido di Camaiore (LU), Italy; ¶ associate professor, Depart- ment of Surgical and Translational Medicine, University of Florence, Florence, Italy Corresponding Author: Prof. Antonio Barone, Department of Surgi- cal, Medical, Molecular and Critical Area Pathology, University of Pisa, Piazza Diaz 10, Camaiore 55041, Italy; e-mail: barosurg@gmail.com © 2015 Wiley Periodicals, Inc. DOI 10.1111/cid.12337 1 588