ASSESSMENT OF TORQUE LOSS IN COMMERCIALLY AVAILABLE IMPLANT/ ABUTMENT SYSTEMS: AN IN VITRO PILOT STUDY
Authors/Creators
- 1. * 1 Post Graduate student, Department of prosthodontics, VS dental college and hospital, Banglore, INDIA. 2 Proffessor, Department of Prosthodontics, VS dental college and hospital, Banglore, INDIA. 3 Proffessor and Head, Department of Prosthodontics, VS dental college and hospital, Banglore, INDIA. 4 Senior resident, Department of Anatomy, IGMC Shimla, INDIA.
Description
ABSTRACT
Aims: The aim of this in vitro pilot study was to assess the torque loss on repeated tightening and loosening of implant abutment screw in commercially available implant systems.
Methods and Material: 2 implant systems were tested with 10 samples in each system. Group A and Group B (n= 10) with connection type morse taper (ADIN GLOBAL IMPLANT SYSTEM) and internal hex (CMI IMPLANT SYSTEM) respectively. Mock osteotomy sites were created in resin blocks and implant analogs were placed. Abutments were placed onto the implant analogs at a torque of 30 Ncm. After 20 minutes the abutment screw was detorqued and the value was noted using digital torque wrench .This procedure was repeated 10 times for each sample.Torque loss and percentage torque loss were calculated.
Statistical analysis used: Descriptive statistics displayed in the form of frequency and percentage. Differences in torque were assessed using ANOVA (p<0.05).
Results: The mean value of torque at first reading for Group A and Group B were ( Rt ¹) =30.82 ±0.42 Ncm and (Rt ¹) = 31.15 ±0.17 Ncm respectively and at tenth reading were (Rt ¹º) = 32.64 ±0.27 Ncm and (Rt ¹º) = 32.85 ±0.42 Ncm respectively.
Conclusions: A progressive decrease in opening torque values was measured in both implant systems. The percentage of torque loss ranged from 1.2 -2.3 % for Group A and 2.2 – 6.45% for Group B. The mean torque loss between Group A and Group B was not statistically significant at p<0.05
KEYWORDS: Torque Loss, Internal Hex, Morse Taper, Abutment Screw Loosening.