An In Vitro Biomechanical Study Comparing the Spiral Linking Technique Against the Pulvertaft Weave for Tendon Repair

A new spiral linking technique for tendon repair in which one end of the tendon is spiralled around the other end has been developed. Using pig trotter extensor tendons, the Pulvertaft weave technique was compared with this new technique. Twenty-five repairs using each technique were tested by tensile loading with an Instron testing machine. The spiral linking technique matched the strength of Pulvertaft method: the mean peak loads were 102 and 105 N, respectively. The Pulvertaft weave was stiffer than the spiral linking technique: mean stiffness of 11.1 and 6.7 N/mm, respectively. The spiral linking technique also absorbed considerably more energy: energy absorbed prior to failure to 90% of peak load, 1.75 and 1.13 kN mm, respectively. In conclusion, the spiral linking technique appears as strong as the Pulvertaft weave and we believe it is easier to perform.

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In vitro Biomechanical Study of Pulvertaft Tendon Weaving Technique

Journal of Orthopaedics Trauma and Rehabilitation ◽

10.1016/j.jotr.2011.04.005 ◽

2011 ◽

Vol 15 (2) ◽

pp. 62-64 ◽

Cited By ~ 1

Author(s):

Yuen Chi-Pan ◽

Yen Chi-Hung ◽

Leung Hon-Bong ◽

Tse Wing-Lim ◽

Ho Pak-Cheong ◽

...

Keyword(s):

Peak Load ◽

Tendon Repair ◽

Early Mobilization ◽

Biomechanical Properties ◽

Biomechanical Study ◽

Load To Failure ◽

Active Mobilization ◽

Passive Mobilization ◽

Single Suture

Background/Purposes The outcome of tendon repair depends on the strength, which allows early active mobilization to achieve better function without rupture. The aims of this study are to assess quantitatively the biomechanical properties and relationship between the number of tendon weaving and suture method using Pulvertaft technique. Results We found that the load to failure was increased with increasing number of weaves and sutures. From 1-weave to 4-weave single suture samples, the peak load to failure was 9.5 N, 19.7 N, 37.5 N, and 42.6 N, respectively. Based on previous studies, wrist and finger tendons should withstand 1–8N on passive mobilization. Conclusion On active mobilization, finger tendon repair need to provide 34 N for immediate mobilization. Therefore, irrespective of number of sutures, both 3- and 4-weave repairs could allow early mobilization biomechanically.

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In Vitro Frictional Forces Generated by Three Different Ligation Methods

The Angle Orthodontist ◽

10.2319/090607-420.1 ◽

2008 ◽

Vol 78 (5) ◽

pp. 917-921 ◽

Cited By ~ 30

Author(s):

Paola Gandini ◽

Linda Orsi ◽

Chiara Bertoncini ◽

Sarah Massironi ◽

Lorenzo Franchi

Keyword(s):

Steel Wire ◽

Testing Machine ◽

Low Friction ◽

Instron Testing Machine ◽

Resistance To Sliding ◽

Titanium Wire ◽

Frictional Forces ◽

Conventional Bracket ◽

Wire Resistance

Abstract Objective: To test the hypothesis that there is no difference between the frictional forces produced by a passive self-ligating bracket (SLB) in vitro and a conventional bracket (CB) used with two types of elastomeric ligatures. Materials and Method: The brackets, wires and ligation methods used in vitro were a passive SLB and a CB used with two types of elastomeric ligatures (conventional elastomeric ligature [CEL] and unconventional elastomeric ligatures [UEL]). The bracket ligation systems were tested with two types of wires (0.014″ super elastic nickel titanium wire and 0.019″ × 0.025″ stainless steel wire). Resistance to sliding of the bracket/wire/ligature systems was measured with an experimental model mounted on the crosshead of an Instron testing machine with a 10 N load cell. Each sample was tested 10 consecutive times under a dry state. Results: Frictional forces close to 0 g were recorded in all tests with SLB and in all tests with UEL on CB with both wire types. Resistance to sliding increased significantly (87–177 g) (P < .05) when CEL on CB was used with both wires. Conclusion: UELs may represent a valid alternative to passive SLBs for low-friction biomechanics.

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An in vitro comparison of the force decay generated by different commercially available elastomeric chains and NiTi closed coil springs

Brazilian Oral Research ◽

10.1590/s1806-83242007000100009 ◽

2007 ◽

Vol 21 (1) ◽

pp. 51-57 ◽

Cited By ~ 23

Author(s):

Ana Cristina Soares Santos ◽

André Tortamano ◽

Sandra Regina Frazatto Naccarato ◽

Gladys Cristina Dominguez-Rodriguez ◽

Julio Wilson Vigorito

Keyword(s):

Artificial Saliva ◽

Testing Machine ◽

In Vitro Study ◽

Original Length ◽

Force Decay ◽

Decay Pattern ◽

The Mean ◽

Initial Force ◽

Elastomeric Chains

This in vitro study was designed to compare the forces generated by commercially available elastomeric chains and NiTi closed coil springs, and to determine their force decay pattern. Forty elastomeric chains and forty NiTi closed coil springs were divided into 4 groups according to the following manufacturers: (1) Morelli®, (2) Abzil®, (3) TP Orthodontics® and (4) American Orthodontics®. The specimens were extended to twice their original length and stored in artificial saliva at 37°C. Initial force was measured by means of an Instron universal testing machine and then at 1, 4, 7, 14, 21, and 28 days. The results revealed that the elastomeric chains delivered a mean initial force of 347 g for Morelli®, 351 g for American Orthodontics®, 402 g for Abzil®, and 404 g for TP Orthodontics®. The NiTi closed coil springs generated a mean initial force of 196 g for American Orthodontics®, 208 g for TP Orthodontics®, 216 g for Abzil®, and 223 g for Morelli®. The mean percentage of force decay observed after 28 days for the elastomeric chains was 37.4% for TP Orthodontics®, 48.1% for American Orthodontics®, 65.4% for Morelli®, and 71.6% for Abzil®. After 28 days, the NiTi closed coil springs presented a mean percentage of force decay of 22.6% for American Orthodontics®, 29.8% for Abzil®, 30.6% for Morelli®, and 45.8% for TP Orthodontics®. At the end of the study, significant differences were observed between the elastomeric chains and the NiTi closed coil springs. The results indicated that the studied NiTi closed coil springs are more adequate for dental movement than the elastomeric chains.

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An in vitro Evaluation of Artificial Caries-like Lesions on Restored Overdenture Abutments

Journal of Dental Research ◽

10.1177/00220345880670031101 ◽

1988 ◽

Vol 67 (3) ◽

pp. 582-584 ◽

Cited By ~ 8

Author(s):

P.P. Kambhu ◽

R.L. Ettinger ◽

J.S. Wefel

Keyword(s):

Light Microscopy ◽

Polarized Light ◽

Polarized Light Microscopy ◽

The Other ◽

Type Ii ◽

Restorative Materials ◽

Abutment Teeth ◽

The Mean ◽

Materials Used

An acidified dialyzed gelatin gel system was used to determine the caries resistance of a variety of restorative materials used to obturate the canal orifice of overdenture abutment teeth. The restorative materials used were Tytin, Tytin + Copalite, P30 + Scotchbond, Fuji Ionomer-Type II, and Miracle Mix. Polarized light microscopy and microradiography were used to examine the caries-like lesions adjacent to the restorations. The lesions formed in the Fuji Ionomer-Type II and Miracle Mix groups appeared arrested at the wall adjacent to the restoration, and did not penetrate apically down the wall as did those associated with the other restorative materials. The mean depths of lesions adjacent to Fuji Ionomer-Type II and Miracle Mix restorations were significantly less than those of Tytin, Tytin + Copalite, or P30 + Scotchbond.

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STUDIES ON THE IN VITRO PRODUCTION OF CORTICOSTEROIDS BY ADRENAL GLANDS FROM NORMOTENSIVE INDIVIDUALS AND HYPERTENSIVE PATIENTS

Canadian Journal of Biochemistry and Physiology ◽

10.1139/y62-032 ◽

1962 ◽

Vol 40 (1) ◽

pp. 285-301 ◽

Cited By ~ 1

Author(s):

Jean Davignon ◽

Erich Koiw ◽

Wojciech Nowaczynski ◽

Gilles Tremblay ◽

Jacques Genest

Keyword(s):

Cushing’S Syndrome ◽

Adrenal Glands ◽

Cushing's Syndrome ◽

The Other ◽

Malignant Hypertension ◽

Unit Weight ◽

Chromatographic Technique ◽

Acth Stimulation ◽

The Mean

The production of aldosterone and other corticosteroids by adrenal glands surgically removed from 5 normotensive subjects with renal disease of various types, 11 patients with arterial hypertension, and 2 with Cushing's syndrome was investigated in vitro by the incubation chromatographic technique. The rate of steroid formation per unit weight of tissue was markedly lower in severe and malignant hypertension and slightly higher in benign hypertension as compared with the rate in normotensive controls. The amount of steroid released varied widely from one gland to the other and showed marked overlapping between the various groups; these variations were most prominent in benign hypertension, less in the normotensive group, and least evident in severe and malignant hypertension. The response of steroidogenesis to ACTH stimulation in vitro was slightly reduced in severe and malignant hypertension. The mean output of aldosterone by adrenal glands from hypertensives was slightly above the mean value obtained with normotensive control glands. The percentage of aldosterone formation in respect to total steroid production was roughly correlated with the severity of hypertension. In four hyperplastic adrenals obtained from two cases of Cushing's syndrome, the in vitro formation of steroids per unit weight of tissue and the response to ACTH did not differ significantly from that found in glands obtained from the other patients under study. The value of in vitro studies for the assessment of the functional capacity of the adrenal cortex is discussed.

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Inhibition of Demineralization at Restoration Margins of Z100 and Tetric EvoCeram Bulk Fill in Dentin and Enamel

Bioengineering ◽

10.3390/bioengineering6020036 ◽

2019 ◽

Vol 6 (2) ◽

pp. 36

Author(s):

Cristina Leon-Pineda ◽

Kevin Donly

Keyword(s):

Light Microscopy ◽

Polarized Light ◽

In Vitro Study ◽

The Other ◽

Solution Ph ◽

Class V ◽

The Mean ◽

Student’S T ◽

Student’S T Test

Recurrent caries is still considered the main reason restorations need to be replaced. There are different materials available now that promise to reduce the possibility of recurrent caries by releasing fluoride and inhibiting restoration marginal caries. The purpose of this in vitro study was to evaluate the demineralization inhibition potential of a non-fluoride-releasing resin (Z100TM 3M, St. Paul, MN, USA) and a glass containing resin-based composite (Tetric EvoCeram Bulk Fill, Ivoclar/Vivadent AG, Schaan, Liechtenstein), which contains fluoride. Class V preparations were placed on 22 premolars; the gingival margin was below the cementoenamel junction and the occlusal margin was placed above the cemento-enamel junction. Ten teeth were randomly selected to be restored with Z100 while the other 10 were restored with Tetric EvoCeram Bulk Fill. Both groups were restored following manufacturer’s instructions. All teeth had an acid resistant varnish placed within one millimeter of the preparation margins. Both groups were placed in artificial caries challenge solution (pH 4.4). At the end of the 4 days; 100 µm buccolingual sections were obtained for each tooth; these were photographed under polarized light microscopy and the demineralized areas adjacent to the restorations were measured and quantified. The mean (±S.D.) area (µm2) of demineralization from the occlusal margin (enamel) and dentin margin were: Z100 2781.889 ± 1045.213; 3960.455 ± 705.964 and for Tetric EvoCeram Bulk Fill 1541.545 ± 1167.027; 3027.600 ± 512.078. Student’s t-test indicated that there was significantly less enamel and dentin demineralization adjacent to Tetric EvoCeram Bulk Fill compared to Z100; there was significantly less demineralization in enamel compared to dentin in both Tetric EvoCeral Bulk Fill and Z100. Tetric EvoCeram Bulk Fill performed better inhibiting demineralization at restoration margins when compared to Z100 and provided better demineralization inhibition in enamel than cementum/dentin.

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Biomechanical study of thoracolumbar junction fixation devices with different diameter dual-rod systems

Journal of Neurosurgery Spine ◽

10.3171/spi.2006.4.3.206 ◽

2006 ◽

Vol 4 (3) ◽

pp. 206-212 ◽

Cited By ~ 5

Author(s):

Ung-Kyu Chang ◽

Jesse Lim ◽

Daniel H. Kim

Keyword(s):

Biomechanical Testing ◽

Load Sharing ◽

Biomechanical Study ◽

Compression Force ◽

Mean Values ◽

Fixation Devices ◽

Thoracolumbar Region ◽

Rod System ◽

The Mean

Object Advances in the design of a smaller-diameter rod system for use in the thoracolumbar region prompted the authors to undertake this biomechanical study of two different thoracolumbar implants. Methods In vitro biomechanical testing was performed using human cadaveric spines. All specimens were loaded to a maximum moment of 5 Nm with 300-N axial preload in six modes of motion. Two types of anterior implants with different rod diameters were applied to intact T10–12 specimens in two groups. The loading was repeated and the range of motion (ROM) was measured. A T-11 corpectomy was then performed and a strain gauge–mounted carbon fiber stackable cage was implanted. The ROM and compression force on the cage were measured, and the mean values were compared between these two groups. With stabilization of the intact spine, ROM decreased least in extension and greatest in bending compared with the intact specimens. After corpectomy and stabilization, ROM increased in extension by 104.89 ± 53.09% in specimens with a 6.35-mm rod insertion and by 83.81 ± 16.96% in those with a 5.5-mm rod, respectively; in flexion, ROM decreased by 26.98 ± 27.43% (6.35 mm) and by 9.59 ± 15.42% (5.5 mm), respectively; and in bending and rotation, both groups each showed a decrease in ROM. The load sharing of the cage was similar between the two groups (the 6.35-mm compared with 5.5-mm rods): 47.44 and 44.73% (neutral), 49.16 and 39.02% (extension), 61.90 and 56.88% (flexion), respectively. Conclusions There were no statistical differences in the ROM and load sharing of the cage when either the 6.35-or 5.5-mm-diameter dual-rod was used.

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Effect of Different Intermediary Bases on Microleakage of a Restorative Material in Class II Box Cavities of Primary Teeth

The International Journal of Artificial Organs ◽

10.5301/ijao.5000566 ◽

2017 ◽

Vol 40 (2) ◽

pp. 82-87 ◽

Cited By ~ 1

Author(s):

Faika Y. Abdelmegid ◽

Fouad S. Salama ◽

Waleed M. Al-Mutairi ◽

Saud K. Al-Mutairi ◽

Sultan O. Baghazal

Keyword(s):

Primary Teeth ◽

In Vitro Study ◽

Class Ii ◽

Positive Control ◽

Negative Control ◽

The Other ◽

Control Groups ◽

Significant Difference ◽

The Mean

Introduction The aim of this in vitro study was to assess and compare the effect of different intermediary bases on microleakage between tooth and a nanocomposite interface in Class II box cavities in primary teeth. Methods Standard Class II box cavities were prepared in 52 primary molars and randomly divided into 9 groups according to the intermediary base used (Multicore Flow, Fuji II LC, SDR, Smart Dentin Replacement, and Biodentine). All specimens were subjected to thermocycling and prepared for microleakage testing and evaluation. Results There was significant difference in the mean ranks of microleakage between the 9 groups, which was observed in the gingival side (p<0.0001) and the occlusal side (p<0.0001). The mean ranks microleakage was significantly higher with experimental SDR, experimental Multicore Flow, and positive control materials when compared with the other 6 groups. The microleakage mean ranks were statistically significantly lower in experimental Fuji II LC, experimental Biodentine, and all negative control groups when compared with the other 3 groups. Conclusions Microleakage is affected by the application of intermediate material. Experimental Biodentine and Fuji II LC showed the lowest microleakage while experimental SDR and experimental Multicore Flow showed the highest microleakage.

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A Biomechanical Evaluation of a Next-Generation Integrated and Modular ACDF Device Possessing Full-Plate, Half-Plate, and No-Profile Fixation Iterations

Global Spine Journal ◽

10.1177/2192568219834252 ◽

2019 ◽

Vol 9 (8) ◽

pp. 826-833

Author(s):

Ripul Panchal ◽

Anup Gandhi ◽

Chris Ferry ◽

Sam Farmer ◽

Jeremy Hansmann ◽

...

Keyword(s):

Plate Fixation ◽

Testing Machine ◽

Axial Rotation ◽

Biomechanical Study ◽

The Novel ◽

Novel Device ◽

Plate Group ◽

Flexion Extension ◽

Group 2

Study Design: In vitro biomechanical study. Objectives: The objective of this in vitro biomechanical range-of-motion (ROM) study was to evaluate spinal segmental stability following fixation with a novel anterior cervical discectomy and fusion (ACDF) device (“novel device”) that possesses integrated and modular no-profile, half-plate, and full-plate fixation capabilities. Methods: Human cadaveric (n = 18, C3-T1) specimens were divided into 3 groups (n = 6/group). Each group would receive one novel device iteration. Specimen terminal ends were potted. Each specimen was first tested in an intact state, followed by anterior discectomy (C5/C6) and iterative instrumentation. Testing order: (1) novel device (group 1, no-profile; group 2, half-plate; group 3, full-plate); (2) novel device (all groups) with lateral mass screws (LMS); (3) traditional ACDF plate + cage; (4) traditional ACDF plate + cage + LMS. A 2 N·m moment was applied in flexion/extension (FE), lateral bending (LB), and axial rotation (AR) via a kinematic testing machine. Segmental ROM was tracked and normalized to intact conditions. Comparative statistical analyses were performed. Results: Key findings: (1) the novel half- and full-plate constructs provided comparable reduction in FE and LB ROM to that of traditional plated ACDF ( P ≥ .05); (2) the novel full-plate construct significantly exceeded all other anterior-only constructs ( P ≤ .05) in AR ROM reduction; and (3) the novel half-plate construct significantly exceeded the no-profile construct in FE ( P < .05). Conclusions: The novel ACDF device may be a versatile alternative to traditional no-profile and independent plating techniques, as it provides comparable ROM reduction in all principle motion directions, across all device iterations.

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