scholarly journals A Biomechanical Evaluation of the Tibia after Retrograde Intramedullary Reaming

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0002
Author(s):  
David J. Ciufo ◽  
Denise Koueiter ◽  
Mariam Alsaleh ◽  
Avianna E. Arapovic ◽  
Kevin C. Baker ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Graft ◽  
Common Mechanism ◽  
Matched Pairs ◽  
Compressive Properties ◽  
Compressive Stiffness ◽  
Intramedullary Reaming ◽  
Graft Harvest ◽  
Torsional Testing ◽  
Significant Difference

Category: Hindfoot; Ankle; Ankle Arthritis; Basic Sciences/Biologics; Trauma Introduction/Purpose: Autologous bone graft is an important tool in the foot and ankle surgeon’s arsenal, and remains the gold standard despite the release of new biologics. The Reamer-Irrigator-Aspirator (RIA) system has become an option for local intramedullary bone graft harvest. Evidence supports the quality of graft and safety of RIA in the femur, and some series have demonstrated its value in tibial reaming for hindfoot fusion. However, there has been no analysis of the mechanical effects of the system on the tibia. The purpose of this study is to investigate the effect of retrograde intramedullary reaming on the mechanical properties of cadaveric tibias, with the hypothesis that this will produce no significant difference in torsional strength between groups. Methods: Intact, fresh frozen tibias were obtained for testing, totaling 11 matched pairs. One tibia was chosen for reaming from each pair with pre-test randomization. The selected tibia was reamed in a retrograde fashion over a guidewire to 12mm, which is the smallest diameter RIA device available. Each tibia was potted and mounted in a custom jig for testing on a servohydraulic test frame. Each specimen was first tested non-destructively for compressive properties using standardized loading rates. Each specimen was then loaded in torsion under constant angular velocity of 9˚/second until failure or the limit of the load cell was reached. Mechanical properties were determined from the load-displacement curve and compared between reamed and unreamed matched pairs using paired samples statistics, with statistical significance set at p=0.05. Results: Specimens were of mean age 56 (range 39-67) years, with 55% being female. The mean compressive stiffness of reamed (560.4 +- 111.7 N/mm) and unreamed (628.2 +- 117.2 N/mm) tibias were not statistically different (p = 0.167). Nine of the reamed specimens and 10 of the unreamed specimens fractured during torsional testing. Torsional testing for stiffness (178.4 Nm/rad +- 59.4 vs 168.1 +- 40.8, p=0.370), rigidity (50.4 Nm2/rad +- 19.1 vs 47.0 +- 13.7, p=0.331), and ultimate load capacity (71.2 Nm +- 24.3 vs 71.9 +- 20.5, p=0.880) showed minimal differences between reamed and unreamed specimens, respectively. Conclusion: Mechanical testing identified no statistically significant differences in torsional or compressive properties of our cadaveric tibias after intramedullary reaming. There was a trend towards decreased compressive stiffness, but this is not a common mechanism of fracture. Our findings suggest that the use of the smallest size RIA system in the tibia does not drastically alter the mechanical properties or require prophylactic fixation. The RIA can be used safely as a method of bone graft harvest or intramedullary debridement in the tibia, as long as appropriate technique is used to avoid eccentric reaming or excessive blood loss.

Combining Microfractures, Autologous Bone Graft, and Autologous Matrix-Induced Chondrogenesis for the Treatment of Juvenile Osteochondral Talar Lesions

2017 ◽  
Vol 38 (5) ◽  
pp. 485-495 ◽  
Author(s):  
Riccardo D’Ambrosi ◽  
Camilla Maccario ◽  
Chiara Ursino ◽  
Nicola Serra ◽  
Federico Giuseppe Usuelli
Keyword(s):  
Bone Graft ◽  
Repeated Measures ◽  
Osteochondral Lesion ◽  
Young Patients ◽  
Case Series ◽  
Autologous Bone Graft ◽  
Lesion Size ◽  
Level Of Evidence ◽  
Significant Difference ◽  
Autologous Bone

Background: The purpose of this study was to evaluate the clinical and radiologic outcomes of patients younger than 20 years, treated with the arthroscopic-talus autologous matrix-induced chondrogenesis (AT-AMIC) technique and autologous bone graft for osteochondral lesion of the talus (OLT). Methods: Eleven patients under 20 years (range 13.3-20.0) underwent the AT-AMIC procedure and autologous bone graft for OLTs. Patients were evaluated preoperatively (T0) and at 6 (T1), 12 (T2), and 24 (T3) months postoperatively, using the American Orthopaedic Foot & Ankle Society Ankle and Hindfoot (AOFAS) score, the visual analog scale and the SF-12 respectively in its Mental and Physical Component Scores. Radiologic assessment included computed tomographic (CT) scan, magnetic resonance imaging (MRI) and intraoperative measurement of the lesion. A multivariate statistical analysis was performed. Results: Mean lesion size measured during surgery was 1.1 cm3 ± 0.5 cm3. We found a significant difference in clinical and radiologic parameters with analysis of variance for repeated measures ( P < .001). All clinical scores significantly improved ( P < .05) from T0 to T3. Lesion area significantly reduced from 119.1 ± 29.1 mm2 preoperatively to 77.9 ± 15.8 mm2 ( P < .05) at final follow-up as assessed by CT, and from 132.2 ± 31.3 mm2 to 85.3 ± 14.5 mm2 ( P < .05) as assessed by MRI. Moreover, we noted an important correlation between intraoperative size of the lesion and body mass index (BMI) ( P = .011). Conclusions: The technique can be considered safe and effective with early good results in young patients. Moreover, we demonstrated a significant correlation between BMI and lesion size and a significant impact of OLTs on quality of life. Level of Evidence: Level IV, retrospective case series.

scholarly journals Regenerative Therapy Modality for Treatment of True Combined Endodontic-Periodontal Lesions: A Randomized Controlled Clinical Trial

2021 ◽  
Vol 18 (12) ◽  
pp. 6220
Author(s):  
Reham AlJasser ◽  
Sundus Bukhary ◽  
Mohammed AlSarhan ◽  
Dalal Alotaibi ◽  
Saleh AlOraini ◽  
...  
Keyword(s):  
Bone Graft ◽  
Bone Grafting ◽  
Endodontic Treatment ◽  
Control Group ◽  
Controlled Clinical Trial ◽  
Bony Defect ◽  
Keratinized Tissue ◽  
Group I ◽  
Significant Difference ◽  
Grafting Procedure

The aim of this in-vivo study was to evaluate/compare the clinical periodontal parameters in patients with true combined endo-perio lesions (EPL), treated with gutta-percha (GP) and mineral trioxide (MTA) as an obturation material alone and with addition of bone grafting in such lesions. 120 Saudi patients (mean age = 41yrs) diagnosed with true combined EPL participated in this study. Group I (control group, n = 30) was treated with conventional endodontic treatment using GP for obturation. Group II (n = 30) was treated with conventional endodontic treatment using MTA for obturation. Group III (n = 30) was treated with conventional endodontic treatment using GP for obturation + grafting procedure to fill the bony defect. Group IV (n = 30) was treated with conventional endodontic treatment using MTA for obturation + grafting procedure to fill the bony defect. Clinical parameters (Pocket depth (PD); Clinical attachment loss (CAL); keratinized tissue width (KTW); gingival phenotype (G.Ph.) and Cone Beam Computed Tomography Periapical Index (CBCTPAI)) were recorded and compared at baseline, 3, 6, 12 months’ interval. For the groups III and IV, CBCTPAI showed significant difference (p < 0.0001) with the other groups at 6 months and 1-year interval. The group with MTA + bone graft showed 76% and 90% patients with 0 score at 6 months and 1-year follow-up, respectively. Comparison of mean values of PD among study groups at 3 months, 6 months and 1 year showed significant difference at 3 months, whereas the mean PD values of subjects in GP + bone graft showed significantly higher PD values than other 3 groups (p = 0.025). Use of GP and MTA for root canal obturation along with periodontal therapy and bone augmentation helps in resolving complex endo-perio lesions. Bone grafting in addition to obturation with MTA was found to be the best treatment strategy in management of EPL cases and is recommended for clinicians who are treating EPL patients.

scholarly journals Comparison of Mechanical Properties of PMMA Disks for Digitally Designed Dentures

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1745
Author(s):  
Tamaki Hada ◽  
Manabu Kanazawa ◽  
Maiko Iwaki ◽  
Awutsadaporn Katheng ◽  
Shunsuke Minakuchi
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Water Sorption ◽  
Water Solubility ◽  
Flexural Modulus ◽  
Manufacturing Method ◽  
Heat Curing ◽  
Significant Difference ◽  
Cad Cam ◽  
Curing Method

In this study, the physical properties of a custom block manufactured using a self-polymerizing resin (Custom-block), the commercially available CAD/CAM PMMA disk (PMMA-disk), and a heat-polymerizing resin (Conventional PMMA) were evaluated via three different tests. The Custom-block was polymerized by pouring the self-polymerizing resin into a special tray, and Conventional PMMA was polymerized with a heat-curing method, according to the manufacturer’s recommended procedure. The specimens of each group were subjected to three-point bending, water sorption and solubility, and staining tests. The results showed that the materials met the requirements of the ISO standards in all tests, except for the staining tests. The highest flexural strength was exhibited by the PMMA-disk, followed by the Custom-block and the Conventional PMMA, and a significant difference was observed in the flexural strengths of all the materials (p < 0.001). The Custom-block showed a significantly higher flexural modulus and water solubility. The water sorption and discoloration of the Custom-block were significantly higher than those of the PMMA-disk, but not significantly different from those of the Conventional PMMA. In conclusion, the mechanical properties of the three materials differed depending on the manufacturing method, which considerably affected their flexural strength, flexural modulus, water sorption and solubility, and discoloration.

scholarly journals Outcomes of Local Bone Graft and Fixation of Proximal Pole Scaphoid Nascent Nonunions and Nonunions

2020 ◽  
Vol 09 (03) ◽  
pp. 203-208
Author(s):  
Kristin E. Shoji ◽  
F. Joseph Simeone ◽  
Sezai Ozkan ◽  
Chaitanya S. Mudgal
Keyword(s):  
Bone Graft ◽  
Common Mechanism ◽  
Study Cohort ◽  
Proximal Pole ◽  
Scaphoid Fractures ◽  
Local Bone ◽  
Case Series Study ◽  
Increased Risk ◽  
Surgical Fixation ◽  
The Mean

Abstract Background Fractures of the proximal pole of the scaphoid have an increased risk of nonunion due to its tenuous blood supply. The optimal treatment of proximal pole scaphoid nonunions remains controversial. Objectives To review a single surgeon's experience with proximal pole scaphoid nascent nonunions (delayed unions) and nonunions that underwent surgical fixation with a cannulated headless compression screw and local autologous bone graft from the distal radius. Patients and Methods After obtaining Institutional Review Board approval, the electronic medical record of one tertiary care center was queried for patients with the diagnosis of “proximal pole scaphoid fractures” who underwent surgical fixation by a single surgeon over an 11-year period (2006–2017). Fifteen patients met initial query criteria; upon review of records, four patients were excluded due to the acute nature of the fracture, and one was excluded as surgical fixation included a vascularized bone graft. Results The final study cohort consisted of 10 patients with a total of 10 proximal pole scaphoid nonunions. Almost all of the patients in this study were male (9/10 [90%]), and sporting activities were the most common mechanism of injury (8/10 [80%]). Volumetric measurements of the scaphoid fractures on computed tomography (CT) revealed that the mean total volume of the scaphoid was 2.4 ± 0.48 cm3 and the mean volume of the proximal pole fragment was 0.38 ± 0.15 cm3. Postoperative CT scans were performed at a mean of 12.4 weeks (range: 8–16 weeks), with seven (7/10 [70%]) showing signs of complete union and three (3/10 [30%]) demonstrating partial union. None of the patients required additional procedures and there were no complications. Conclusions Our results suggest that proximal pole scaphoid fractures with delayed union and nonunion treated with surgical fixation and autologous local bone graft heal without the need for more complex vascularized procedures. The volume of the proximal pole fragment did not correlate with increased risk of ongoing nonunion after the index procedure. Level of Evidence This is a Level IV, case series study.

Investigation on the mechanical properties of press-hardened boron steel sheets using the conductive heating technique

2020 ◽  
Vol 234 (8) ◽  
pp. 1084-1098
Author(s):  
O Kocar ◽  
H Livatyalı
Keyword(s):  
Mechanical Properties ◽  
High Speed ◽  
Boron Steel ◽  
Fast Heating ◽  
Heating Method ◽  
Conductive Heating ◽  
Press Hardening ◽  
High Speed Impact ◽  
Significant Difference ◽  
Structural Parts

An aluminized 22MnB5 (Boron) steel sheet, used for structural parts in the automotive industry, was subjected to press-hardening followed by austenitizing, both in a conventional furnace and via the conductive (electric resistance) heating method, an innovative technique based on the Joule’s principle for fast heating of the sheet metal. Conductive heating presents a number of advantages over the in-furnace heating method. These include a more efficient use of energy, as well as the requirement of less time and space for heating, thus lowering costs. After press-hardening was performed using both methods, the microstructural and mechanical characterizations of both specimens were examined for optical microscopy, hardness, tensile strength, and high-speed impact tests. The results showed that the press-hardening process transformed the ferritic–pearlitic microstructure in the as-received state into martensite after die quenching and caused a substantial increase in hardness and strength at the expense of ductility and impact toughness. On the other hand, no significant difference was observed in either the microstructure or mechanical properties with respect to the heating method used. The results obtained in the present investigation concur with the findings of current literature.

Bending Properties of General Purpose Stainless Steel Wire Formed for Orthodontic Use

2013 ◽  
Vol 746 ◽  
pp. 394-399
Author(s):  
Niwat Anuwongnukroh ◽  
Yosdhorn Chuankrerkkul ◽  
Surachai Dechkunakorn ◽  
Pornkiat Churnjitapirom ◽  
Theeralaksna Suddhasthira
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Orthodontic Treatment ◽  
Steel Wire ◽  
General Purpose ◽  
Stainless Steel Wire ◽  
Bending Test ◽  
Bending Properties ◽  
Steel Wires ◽  
Significant Difference

The archwire is generally used in fixed appliances for orthodontic treatment to correct dental malocclusion. However, it is interesting to know whether general purpose stainless steel wire could replace commercial orthodontic archwire in orthodontic practice for economic reasons. The purpose of this study was to determine the bending properties of general purpose stainless steel wire compared with commercial orthodontic stainless steel wires after forming as an archwire for orthodontic use. The samples used in this study were 90 general purpose and 45 commercial (Highland) round stainless steel wires in 0.016, 0.018, and 0.020 sizes (30 general purpose and 15 commercial wires for each size). All 15 general purpose stainless steel wires with different sizes were formed into orthodontic archwire with a Universal Testing Machine. All samples were tested (three-point bending test) for mechanical properties. The results showed no significant difference between general purpose and commercial orthodontic wires in size 0.016 for 0.1 mm offset bending force, 0.2% yield strength, and springback. Although many mechanical properties of general purpose wires differed from commercial wires, their values conformed to other previous studies within the range of clinical acceptance. In conclusion, orthodontic formed general purpose round stainless steel wires had statistically different (p <0.05) mechanical properties from commercial orthodontic stainless steel wires (Highland) but the mechanical properties were acceptable to use in orthodontic treatment.

scholarly journals PROPERTIES OF PARTICLEBOARD PANELS MADE OF SUGARCANE PARTICLES WITH AND WITHOUT HEAT TREATMENT

2019 ◽  
Vol 43 (5) ◽  
Author(s):  
Emerson Gomes Milagres ◽  
Raiana Augusta Grandal Savino Barbosa ◽  
Karine Fernandes Caiafa ◽  
Gabriel Soares Lopes Gomes ◽  
Tatiana Aurora Condezo Castro ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Sugarcane Bagasse ◽  
Linear Expansion ◽  
Basic Density ◽  
Water Vapor Adsorption ◽  
Thickness Swelling ◽  
Specific Mass ◽  
Heat Treated ◽  
Significant Difference

ABSTRACT The objective of this work was to determine the properties of particleboard panels made of “in natura” sugarcane bagasse particles, heated at 250 °C for 5 minutes. Various particle proportions were utilized to produce the panels and their properties were compared with that of a panel made of Pinus sp. The panels were produced with 8% tannin formaldehyde adhesive, and 0.5% paraffin emulsion, being pressed at 32 kgf.cm-2 for 10 minutes at 180 ° C. It was determined the basic density of the “in natura” and heat-treated particles, their chemical composition, as well as the compression ratio necessary to obtain panels with density equal to 0.75 g.cm-3. The basic density of the panels, hygroscopic equilibrium humidity, thickness swelling, linear expansion, water vapor adsorption, modulus of elasticity and rupture, perpendicular traction, screw pullout, and Janka hardness were determined. The basic densities of Pinus particles and sugarcane bagasse without and with heat treatment were 0.46, 0.27 and 0.30 g.cm-3, respectively. The average specific mass of the panels was 0.74 g.cm-3 with no significant difference between them. Generally, panels made of sugarcane particles were less hygroscopic and dimensionally more stable than panels made of Pinus particles. However, the perpendicular tensile strength, screw pullout and Janka hardness of these panels were higher than for the Pinus panels. The heat treatment of sugarcane bagasse particles resulted in better mechanical properties of perpendicular traction and Janka hardness. In general, the panels are within the limits set by ANSI A208.1. It is therefore possible to replace panels made of Pinus particles for the ones made of sugarcane bagasse, provided that at least 25% of the particles are heat treated for 5 minutes at 250 ° C.

scholarly journals Histomorphometric Evaluation of Socket Preservation Using Autogenous Tooth Biomaterial and BM-MSC in Dogs

Scanning ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Jin-Hyun Kim ◽  
Puneet Wadhwa ◽  
HongXin Cai ◽  
Dong-Hyung Kim ◽  
Bing Cheng Zhao ◽  
...  
Keyword(s):  
Bone Graft ◽  
Alveolar Bone ◽  
Control Group ◽  
Ridge Preservation ◽  
Graft Material ◽  
Socket Preservation ◽  
Bone Graft Material ◽  
Premolar Extraction ◽  
Bone Width ◽  
Significant Difference

This study is aimed at assessing the dimensional alterations occurring in the alveolar bone after premolar extraction in dogs with histomorphometric and histological analysis. After atraumatic premolar extraction, tooth-derived bone graft material was grafted in the extraction socket of the premolar region in the lower jaws of six dogs in two experimental groups. In the second experimental group, BM-MSCs were added together with the graft. The control was left untreated on the opposite side. After twelve weeks, all six animals were sacrificed. Differences in alveolar bone height crests lingually and buccally, and alveolar bone width at 1, 3, and 5 mm infracrestally, were examined. Histologic study revealed osteoconductive properties of tooth biomaterial. A statistically significant difference was detected between the test and control groups. In the test groups, a reduced loss of vertical and horizontal alveolar bone dimensions compared with the control group was observed. Tooth bone graft material may be considered useful for alveolar ridge preservation after tooth extraction, as it could limit the natural bone resorption process.

scholarly journals The effect of calcinated hydroxyapatite and magnesium doped hydroxyapatite as fillers on the mechanical properties of a model BisGMA/TEGDMA dental composite initially and after aging

10.30544/403 ◽  
2018 ◽  
Vol 24 (4) ◽  
Author(s):  
Tamara Matic ◽  
Maja Ležaja Zebić ◽  
Ivana Cvijović-Alagić ◽  
Vesna Miletić ◽  
Rada Petrović ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Body Fluid ◽  
Control Sample ◽  
Dental Composite ◽  
In Vitro Bioactivity ◽  
Significant Difference ◽  
Nanosized Hydroxyapatite ◽  
Glass Fillers ◽  
Mg Doped

The aim of this study was to investigate the possibility of modifying model BisGMA/TEGDMA dental composite by substituting 10 wt. % of conventional glass fillers with bioactive fillers based on calcinated nanosized hydroxyapatite (HAp) and Mg doped hydroxyapatite (Mg-HAp). HAp and Mg-HAp powders were synthesized hydrothermally. Mechanical properties: hardness by Vickers (HV) and flexural strength (Fs) were tested initially and after being stored for 28 days in simulated body fluid (SBF). The experimental composites with HAp and Mg-HAp particles showed no statistically significant difference in HV compared to the control (p>0.05) either initially or after storage. Although mean Fs values of modified composites tested initially were lower (62 MPa) than those of the control (72 MPa), after 28 days of storage in SBF Fs values were greater for modified composites (42 MPa control sample, 48 MPa HAp and Mg-HAp samples). In vitro bioactivity of BisGMA/TEGDMA composites with HAp and Mg-HAp particles after 28 days in SBF was not detected. Keywords: hydroxyapatite; magnesium; dental composite; mechanical properties;

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