Assessment of correlation between computerized tomography values of the bone, and maximum torque and resonance frequency values at dental implant placement

Abstract

The aim of this study was to determine the bone density in the designated implant sites using computerized tomography (CT), the fastening torque values of dental implants, and the implant stability values using resonance frequency analysis. Further aim was to evaluate a possible correlation between bone density, fastening torque and implant stability. Eighty-five patients were treated with 158 Brånemark System implants. CT machine was used for preoperative evaluation of the jawbone for each patient, and bone densities were recorded in Hounsfield units (HU). The fastening torque values of all implants were recorded with the OsseoCare equipment. Implant stability measurements were performed with the Osstell machine. The average bone density and fastening torque values were 751.4 +/- 256 HU and 39.7 +/- 7 Ncm for 158 implants. The average primary implant stability was 73.2 +/- 6 ISQ for seventy implants. Strong correlations were observed between the bone density, fastening torque and implant stability values of Brånemark System TiUnite MKIII implants at implant placement (P < 0.001). These results strengthen the hypothesis that it may be possible to predict and quantify initial implant stability and bone quality from pre-surgical CT diagnosis.

Surface treatment of implants: primary stability

“…In response to the attempts at finding a human bone substitute for in vitro studies, resonance frequency values of human bone, close to those of the wood and 40 PCF Nacional ® polyurethane substrates observed in this study, may be cited; such as in the study by Turkylmaz et al 4 , in which the average ISQ value was 73.2, similar to that found in the work of Degidi 7 (73.5) and the studies by Aksoy 1 (72.28) and Park (76.6) 23 . These results, using in vivo bone, confirm the conclusions of the present research, in which the substrates that most resembled pig bone were wood and 40 PCF polyurethane, as there was no statistical difference between treated implants when inserted into either of these materials or in bone, and no statistical difference between machined implants when inserted in either 40 PCF polyurethane or in bone.…”

“…Many studies claim that implants inserted in the mandible have higher success rates than those inserted in the maxilla [10][11] and high implant failure rates are observed when there is poor bone mineralization or limited bone resistance in terms of perceived tactile sensitivity during drilling [3][4] . As mechanical behavior is vital for obtaining osseointegration, several classifications have been suggested for bone quality 5 , however they are neither very objective nor reproducible 4 . Degidi et al 7 claim that a surgeon's ability to predict primary stability through subjective analysis is not always effective, mainly with low resonance frequency and insertion torque values.…”

“…The use of endosseous implants in oral rehabilitation has witnessed a significant increase in recent years due to studies showing high success rates [1][2][3][4][5] and scientific and industrial developments that have broadened the application of these implants. To achieve osseointegration, it is crucial that during surgery the implant is stabilized in the receiving bone site 6 , attaining primary stability 2,[6][7][8][9][10] .…”

“…The Periotest is an instrument that assesses tooth or implant mobility 8 , however its applicability for this purpose is poor due to its low senitivity 2,4,8 . Insertion torque is equal to the implant's final seating torque in the receiving bone site 6 , but this can only be assessed per operandum 2,8 .…”

“…This consists of a clinical assessment of the implant's vibratory oscillations by way of a transducer connected to it. [3][4]6,8 . The value, given by the implant stability quotient (ISQ), is influenced by the bone adjacent to the implant and the rigidity of the bone-implant interface 2-4,9,12-13 .…”