Effects of Implanting Torques on Implant Osseointegration in an Animal Model

Objective: To investigate the effect of insertion torque on implant osseointegration in an animal model. Methods: First, the first to fourth premolars of nine healthy adult beagles’ mandibular were extracted to form an edentulous area, and then the beagles were equally divided into three groups with different torques (low torque: 10–30 Ncm; medium torque: 30–50 Ncm; high torque: > 70 Ncm). Three implants were placed on each side of the edentulous area of the beagles (54 total), and the dogs were observed for 8 weeks. Implant performance and removal torque values (RTV) were determined at 1, 4, and 8 weeks after surgery. In addition, the expression ratios of OPG and RANKL mRNAs in the surrounding bone tissue were determined. Results: None of the 54 implants showed loosening or loss, and no significant bone resorption was observed. The removing torques and the expression ratios of OPG and RANKL mRNAs showed differences at 1 and 4 weeks after surgery, while they converged at 8 weeks after the surgery (p > 0.05). Conclusion: The osteointegration process lasted approximately 8 weeks depending on the difference in parameters, and all parameters showed the same values even though the insertion torques at the beginning were different.

The influence of bracket torque on external apical root resorption in bimaxillary protrusion patients: a retrospective study

Background To evaluate the difference in root resorption between standard torque self-ligating brackets and high torque self-ligating brackets in bimaxillary protrusion patients after orthodontic treatment. Methods Pre-treatment and post-treatment Cone beam computed tomography (CBCT) of 32 patients (16 treated with the high torque DamonQ 0.022″ bracket and 16 with the 0.022″ standard torque self-ligating bracket) were selected. The first premolars were extracted from all patients before treatment. After mini-screw implants were inserted into the buccal region between the second premolar and first molar, 150 g of force was applied to retract the upper and lower anterior teeth to close the extraction space on each side. CBCT images of all patients were taken before and after treatment. Three-dimensional reconstruction of the maxillary central incisor, lateral incisor and canine was conducted with Mimics 20.0 software. The volumes of the roots were calculated using Gomagics Studio 12.0 software. The differences between the pre-treatment and post-treatment root volumes were statistically evaluated with a paired-samples t-test. Results There was no statistically significant difference in root resorption degree between the two kinds of torque brackets. The patient’s degree of root resorption in the high torque self-ligating group was greater than that in the standard torque group. Conclusions There was no significant difference in root external apical resorption between the high torque self-ligating brackets and the standard torque self-ligating brackets in bimaxillary protrusion patients.

Effects of insertion torque values on the marginal bone loss of dental implants installed in sheep mandibles

The aim of the present in vivo study was to analyze and compare the effects on the crestal bone healing of two different implant macrogeometries installed in fresh socket areas and in normal bone areas with different insertion torque values. Two implant macrogeometries were used in the present study, DuoCone implant (DC) and Maestro implant (MAE), forming four groups: group DCws, in which the implants were installed in healing bone (without a socket); group DCfs, in which the implants were installed in post-extraction areas (fresh sockets); group MAEws, in which the implants were installed in healing bone (without a socket); group MAEfs, in which the implants were installed in post-extraction areas (fresh sockets). After 30 and 90 days of implantations in the bilateral mandibles of 10 sheep, eighty implants were evaluated through digital X-ray images and histologic slices. The crestal bone position in relation to the implant platform shoulder was measured and compared. The measured insertion torque was 47.2 ± 4.69 Ncm for the DCws group, 43.4 ± 4.87 Ncm for the DCfs group, 29.3 ± 3.16 Ncm for the MAEws group, and 27.7 ± 4.41 Ncm for the MAEfs group. The radiographic mesio-distal and histological bucco-lingual analyses showed significantly greater vertical bone loss in the implants installed with high torque (DC groups) in comparison to the implants installed with a low torque (MAE groups) (p < 0.05), at both evaluation times. In general, low insertion torque values (Maestro implants) showed better results of MBL when compared to implants installed with higher torque values (Duo Cone implants). Moreover, our results showed that the implants installed in the sites without sockets showed a less MBL in comparison with the implants installed in sites of fresh sockets.

Lab-Scale Twin-Screw Micro-Compounders as a New Rubber-Mixing Tool: ‘A Comparison on EPDM/Carbon Black and EPDM/Silica Composites’

The research and development (R&D) in rubber formulation development require reproducible, repeatable, fast, accurate, and efficient sample preparation. The lab-scale formulation development is conventionally carried out using small-scale internal mixers and two-roll mills. However, high torque laboratory twin-screw micro-compounder, which have been serving the plastic industry for more than 30 years, can be used to formulate new rubber compounds for fast and accurate sample preparation that on top can contribute to the economics of R&D. In this study, we investigated the possibility of using lab-scale 15 mL high torque twin-screw micro-compounder as a tool for new rubber compound development. For this purpose, we formulated EPDM/carbon black and EPDM/silica recipes through conventional way using a Banbury mixer followed by a two-roll mill, and through the possible way using a lab-scale 15 mL twin-screw micro-compounder. We crosslinked both systems via hot press at a predefined temperature and time. The rheological and mechanical properties of the compounds were investigated. Moreover, the dispersion of carbon black and silica in the EPDM matrix was judged by DisperGrader and scanning electron microscope (SEM). The conventional way of sample preparation was compared with a possible sample preparation method based on materials’ parameters and ease of operation.

Implementation of high-voltage kicker system for “ROSTU” middle-size league robot soccer

Middle-size robot soccer is one of the divisions that competed in national events such as the National Indonesia Robotics Competition and international competitions such as the middle size league (MSL). One of the main components in soccer robots is the kicker system. The kicker system is expected to be high torque, robust, and safe. In this work, a high voltage kicker system is designed and evaluated to substitute ROSTU's previous kicker system. This high voltage solenoid-based kicker system works at 380V and uses the electromagnetic force principle to move a ball. The performance criteria of the kicker system are it can move a ball with a mass of around 1 kg for a minimum range of 3 m and control the charging and discharging process in high voltage conditions. The experiment results show that the kicker system can move a ball with a mass of 1.06 kg, a difference kick distance from 100cm to 350cm, and a monitoring system that can show information about the capacitor voltage and system status.

Fatigue Life Calculation Method and Experimental Study of the Multiple Corrugated Diaphragm Coupling

The multiple corrugated diaphragm (MCD) coupling is a new flexible coupling developed based on the diaphragm and diaphragm disc coupling. Compared to traditional couplings, the MCD coupling has the advantages of high torque diameter, high torque weight, and high compensation capability. It is more suitable for high power speed and high power density working conditions. The MCD coupling is subjected to axial, angular, torque, and centrifugal force loads. The fatigue failure caused by alternating stress is the primary failure mode of the coupling. The fatigue life of the MCD coupling cannot be accurately calculated because of the complexity of the force in operation. Some theoretical simplifications can only obtain the approximate result. In this paper, a parameterized finite element model of the MCDs is established. A method for calculating the fatigue safety factor of the MCD coupling is proposed based on a modified Goodman curve to know the design of the MCD coupling. The feasibility of this method is verified by the fatigue life test of the coupling.

Integration and Testing of a High-Torque Servo-Driven Joint and Its Electronic Controller with Application in a Prototype Upper Limb Exoskeleton

Mechatronic systems that allow motorized activation in robotic exoskeletons have evolved according to their specific applications and the characteristics of the actuation system, including parameters such as size, mechanical properties, efficiency, and power draw. Additionally, different control strategies and methods could be implemented in various electronic devices to improve the performance and usability of these devices, which is desirable in any application. This paper proposes the integration and testing of a high-torque, servo-driven joint and its electronic controller, exposing its use in a robotic exoskeleton prototype as a case study. Following a brief background review, the development and implementation of the proposal are presented, allowing the control of the servo-driven joint in terms of torque, rotational velocity, and position through a straightforward, closed-loop control architecture. Additionally, the stability and performance of the servo-driven joint were assessed with and without load. In conclusion and based on the obtained results, the servo-driven joint and its control system demonstrate consistent performance under the proposed test protocol (max values: angular velocity 97 °/s, torque 33 Nm, positioning RMSE 1.46°), enabling this approach for use in various applications related to robotic exoskeletons, including human performance enhancement, rehabilitation, or support for daily living activities.

A Review of Transverse Flux Machines Topologies and Design

High torque and power density are unique merits of transverse flux machines (TFMs). TFMs are particularly suitable for use in direct-drive systems, that is, those power systems with no gearbox between the electric machine and the prime mover or load. Variable speed wind turbines and in-wheel traction seem to be great-potential applications for TFMs. Nevertheless, the cogging torque, efficiency, power factor and manufacturing of TFMs should still be improved. In this paper, a comprehensive review of TFMs topologies and design is made, dealing with TFM applications, topologies, operation, design and modeling.