scholarly journals Laser resonance frequency analysis of pedicle screw stability: A cadaveric model bone study

2021 ◽  
Author(s):  
Daisuke Nakashima ◽  
Katsuhiro Mikami ◽  
Shunsuke Kikuchi ◽  
Masaharu Nishikino ◽  
Toshiyuki Kitamura ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Pedicle Screw ◽  
Frequency Analysis ◽  
Resonance Frequency Analysis ◽  
Laser Resonance ◽  
Cadaveric Model

scholarly journals Machine Learning-Based Diagnosis in Laser Resonance Frequency Analysis for Implant Stability of Orthopedic Pedicle Screws

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7553
Author(s):  
Katsuhiro Mikami ◽  
Mitsutaka Nemoto ◽  
Takeo Nagura ◽  
Masaya Nakamura ◽  
Morio Matsumoto ◽  
...  
Keyword(s):  
Machine Learning ◽  
Resonance Frequency ◽  
Frequency Analysis ◽  
Pedicle Screws ◽  
Peak Torque ◽  
Resonance Frequency Analysis ◽  
Implant Stability ◽  
Laser Resonance ◽  
Analysis Scheme ◽  
Polyaxial Screws

Evaluation of the initial stability of implants is essential to reduce the number of implant failures of pedicle screws after orthopedic surgeries. Laser resonance frequency analysis (L-RFA) has been recently proposed as a viable diagnostic scheme in this regard. In a previous study, L-RFA was used to demonstrate the diagnosis of implant stability of monoaxial screws with a fixed head. However, polyaxial screws with movable heads are also frequently used in practice. In this paper, we clarify the characteristics of the laser-induced vibrational spectra of polyaxial screws which are required for making L-RFA diagnoses of implant stability. In addition, a novel analysis scheme of a vibrational spectrum using L-RFA based on machine learning is demonstrated and proposed. The proposed machine learning-based diagnosis method demonstrates a highly accurate prediction of implant stability (peak torque) for polyaxial pedicle screws. This achievement will contribute an important analytical method for implant stability diagnosis using L-RFA for implants with moving parts and shapes used in various clinical situations.

Influence of Bone Quality, Drilling Protocol, Implant Diameter/Length on Primary Stability: An In Vitro Comparative Study on Insertion Torque and Resonance Frequency Analysis

2020 ◽  
Vol 46 (3) ◽  
pp. 182-189 ◽  
Author(s):  
Davide Farronato ◽  
Mattia Manfredini ◽  
Michele Stocchero ◽  
Mattia Caccia ◽  
Lorenzo Azzi ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Bone Quality ◽  
Frequency Analysis ◽  
Primary Stability ◽  
Mean Difference ◽  
Insertion Torque ◽  
Resonance Frequency Analysis ◽  
Bone Response ◽  
Implant Length

The aim of this study was to evaluate the influence of bone quality, drilling technique, implant diameter, and implant length on insertion torque (IT) and resonance frequency analysis (RFA) of a prototype-tapered implant with knife-edge threads. The investigators hypothesized that IT would be affected by variations in bone quality and drilling protocol, whereas RFA would be less influenced by such variables. The investigators implemented an in vitro experiment in which a prototype implant was inserted with different testing conditions into rigid polyurethane foam blocks. The independent variables were: bone quality, drilling protocol, implant diameter, and implant length. Group A implants were inserted with a conventional drilling protocol, whereas Group B implants were inserted with an undersized drilling protocol. Values of IT and RFA were measured at implant installation. IT and RFA values were significantly correlated (Pearson correlation coefficient: 0.54). A multivariable analysis showed a strong model. Higher IT values were associated with drilling protocol B vs A (mean difference: 71.7 Ncm), implant length (3.6 Ncm increase per mm in length), and substrate density (0.199 Ncm increase per mg/cm3 in density). Higher RFA values were associated with drilling protocol B vs A (mean difference: 3.9), implant length (1.0 increase per mm in length), and substrate density (0.032 increase per mg/cm3 in density). Implant diameter was not associated with RFA or IT. Within the limitations of an in vitro study, the results of this study suggest that the studied implant can achieve good level of primary stability in terms of IT and RFA. A strong correlation was found between values of IT and RFA. Both parameters are influenced by the drilling protocol, implant length, and substrate density. Further studies are required to investigate the clinical response in primary stability and marginal bone response.

scholarly journals Effects of photofunctionalization on early osseointegration of titanium dental implants in the maxillary posterior region: a randomized double-blinded clinical trial

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Bada Choi ◽  
Ye Chan Lee ◽  
Kyung Chul Oh ◽  
Jae Hoon Lee
Keyword(s):  
Clinical Trial ◽  
Resonance Frequency ◽  
Bone Quality ◽  
Frequency Analysis ◽  
Treated Group ◽  
Posterior Region ◽  
Resonance Frequency Analysis ◽  
Group Iii ◽  
The Stability ◽  
Double Blinded

Abstract Background This study aimed to investigate the effects of ultraviolet (UV) photofunctionalization on the stability of implants during the early phase in the posterior region of the maxilla. The study was a randomized double-blinded clinical trial. Half of the participants received conventional commercial implants while the other half received UV-irradiated implants. The surgical sites were classified into three bone quality groups (II, III, IV) based on the grayscale value measured on cone-beam computed tomography. The values obtained from resonance frequency analysis were recorded immediately after implant placement and at 4 weeks and at 4 months postoperatively. The marginal bone level of the implants was evaluated using periapical radiographs at 4 weeks, 4 months, and 1 year postoperatively. Results Fifty-seven implants placed in 34 participants were analyzed in this study. In group III, significant differences were observed in terms of the differences of resonance frequency analysis values at 4 weeks (p = 0.004) and 4 months (p = 0.017) postoperatively. In group II, the UV-treated group showed significantly lesser bone loss at 4 weeks post-operatively (p = 0.037). Conclusions Within the limitation of the present study, we concluded that UV surface treatment on implants may increase the initial stability in the region of the maxilla with poor bone quality.

scholarly journals Does the manual insertion torque of smartpegs affect the outcome of implant stability quotients (ISQ) during resonance frequency analysis (RFA)?

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Ingrid Kästel ◽  
Giles de Quincey ◽  
Jörg Neugebauer ◽  
Robert Sader ◽  
Peter Gehrke
Keyword(s):  
Resonance Frequency ◽  
Frequency Analysis ◽  
Insertion Torque ◽  
Resonance Frequency Analysis ◽  
Implant Stability ◽  
Reliable Determination ◽  
Torque Values ◽  
Finger Pressure

Abstract Background There is disagreement about the optimal torque for tightening smartpegs for resonance frequency analysis (RFA). Subjective finger pressure during hand tightening could affect the reliability of the resulting values. The aim of the current study was therefore to assess whether or not the insertion torque of a smartpeg magnetic device influences the implant stability quotient (ISQ) value during RFA. Methods Thirty self-tapping screw implants (XiVE S, Dentsply Sirona Implants, Bensheim, Germany) with a diameter of 3.8 mm and a length of 11 mm were inserted in three cow ribs with a bone quality of D1. The RFA value of each implant was measured (Ostell, FA W&H Dentalwerk, Bürmoos, Austria) in two orthogonal directions (mesial and buccal) after tightening the corresponding smartpeg type 45 with a mechanically defined value of 5 Ncm (Meg Torq device, Megagen, Daegu, South Korea) (test). Additionally, 4 different examiners measured the RFA after hand tightening the smartpegs, and the results were compared (control). Insertion torque values were determined by measuring the unscrew torque of hand seated smartpegs (Tohnichi Manufacturing Co. Ltd, Tokyo, Japan). Results The ISQ values varied from 2 to 11 Ncm by hand tightening and from 2 to 6 Ncm by machine tightening. The comparison of hand and machine tightening of smartpegs displayed only minor differences in the mean ISQ values with low standard deviations (mesial 79.76 ± 2,11, buccal 77.98 ± 2,) and no statistical difference (mesial p = 0,343 and buccal p = 0,890). Conclusions Manual tightening of smartpeg transducers allows for an objective and reliable determination of ISQ values during RFA.

A Numerical Approach of Estimating Dental Implant Healing Process Using Resonance Frequency Analysis (RFA)

2011 ◽  
Author(s):  
Reza Harirforoush ◽  
Siamak Arzanpour
Keyword(s):  
Resonance Frequency ◽  
Dental Implant ◽  
Frequency Analysis ◽  
Healing Process ◽  
Primary Stability ◽  
High Sensitivity ◽  
Titanium Implant ◽  
Resonance Frequency Analysis ◽  
Early Assessment ◽  
Bone Interface

This paper investigates primary stability of dental implant that indicates the process of bone-implant integration. This integration is known to happen at the boundary of the bone and dental implant contact surface. The resonance frequency of dental implant is used as the parameter for this investigation due to its high sensitivity to boundary condition variations. In this study, resonance frequency analysis (RFA) of the jaw-implant structure is carried out using finite element modeling. The FEM analyses are conducted in ANSYS modal analysis simulation environment. The FEM model of the structure includes titanium implant, Cancellous and cortical bone. Different implant-bone interface conditions are studied for this investigation. Various boundary conditions were studied to identify natural frequencies of jaw-implant structure. Our analysis shows that the resonance frequency of the implant increases during the healing period and reaches a plateau when the implant-bone interface was fully integrated. The results show that RFA could be suggested as a non-invasive, reliable and accurate diagnostic method for early assessment of the healing stages.

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