scholarly journals Mechanical Evaluation of the Stability of One or Two Miniscrews under Loading on Synthetic Bone

2020 ◽  
Vol 11 (4) ◽  
pp. 80
Author(s):  
Andrea Pradal ◽  
Ludovica Nucci ◽  
Nicola Derton ◽  
Maria Elena De Felice ◽  
Gianluca Turco ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Primary Stability ◽  
Maximum Load ◽  
Mean Value ◽  
Yield Load ◽  
Synthetic Bone ◽  
Group A ◽  
The Stability ◽  
Group B ◽  
Temporary Anchorage Device

The aim of the present study was to evaluate the primary stability of a two-miniscrew system inserted into a synthetic bone and to compare the system with the traditional one. Forty-five bi-layered polyurethane blocks were used to simulate maxillary cancellous and cortical bone densities. Samples were randomly assigned to three groups—one-miniscrew system (Group A, N = 23), two-miniscrew system (Group B, N = 22) and archwire-only (Group C, N = 10). A total of 67 new miniscrews were subdivided into Group A (23 singles) and Group B (22 couples). 30 mm of 19″ × 25″ archwires were tied to the miniscrew. The load was applied perpendicularly to the archwire. Maximum Load Value (MLV), Yield Load (YL) and Loosening Load (LL) were recorded for each group. The YL of Group B and C had a mean value respectively of 4.189 ± 0.390 N and 3.652 ± 0.064 N. The MLV of Group A, B and C had a mean value respectively of 1.871 ± 0.318N, of 4.843 ± 0.515 N and 4.150 ± 0.086 N. The LL of Group A and B had a mean value respectively of 1.871 ± 0.318 N and of 2.294 ± 0.333 N. A two- temporary anchorage device (TAD) system is on average stiffer than a one-TAD system under orthodontic loading.

scholarly journals The Bone Buttress Theory: The Effect of the Mechanical Loading of Bone on the Osseointegration of Dental Implants

Biology ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 12
Author(s):  
David Chavarri-Prado ◽  
Aritza Brizuela-Velasco ◽  
Ángel Álvarez-Arenal ◽  
Markel Dieguez-Pereira ◽  
Esteban Pérez-Pevida ◽  
...  
Keyword(s):  
Dental Implants ◽  
Mechanical Loading ◽  
Bone Growth ◽  
Bone Matrix ◽  
Test Group ◽  
Control Group ◽  
Group A ◽  
Bone To Implant Contact ◽  
The Stability ◽  
Group B

Objectives: To determine the effect of mechanical loading of bone on the stability and histomorphometric variables of the osseointegration of dental implants using an experimental test in an animal model. Materials and Methods: A total of 4 human implants were placed in both tibiae of 10 New Zealand rabbits (n = 40). A 6-week osseointegration was considered, and the rabbits were randomly assigned to two groups: Group A (Test group) included 5 rabbits that ran on a treadmill for 20 min daily during the osseointegration period; Group B (Controls) included the other 5 that were housed conventionally. The monitored variables were related to the primary and secondary stability of the dental implants (implant stability quotient—ISQ), vertical bone growth, bone to implant contact (BIC), area of regenerated bone and the percentage of immature matrix. Results: The results of the study show a greater vertical bone growth (Group A 1.26 ± 0.48 mm, Group B 0.32 ± 0.47 mm, p < 0.001), higher ISQ values (Group A 11.25 ± 6.10 ISQ, 15.73%; Group B 5.80 ± 5.97 ISQ, 7.99%, p = 0.006) and a higher BIC (Group A 19.37%, Group B 23.60%, p = 0.0058) for implants in the test group, with statistically significant differences. A higher percentage of immature bone matrix was observed for implants in the control group (20.68 ± 9.53) than those in the test group (15.38 ± 8.84) (p = 0.108). A larger area of regenerated bone was also observed for the test implants (Group A 280.50 ± 125.40 mm2, Group B 228.00 ± 141.40 mm2), but it was not statistically significant (p = 0.121). Conclusions: The mechanical loading of bone improves the stability and the histomorphometric variables of the osseointegration of dental implants.

scholarly journals The effect of nano-hydroxyapatite/chitosan scaffolds on rat calvarial defects for bone regeneration

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Emmanouil Chatzipetros ◽  
Spyros Damaskos ◽  
Konstantinos I. Tosios ◽  
Panos Christopoulos ◽  
Catherine Donta ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Mean Value ◽  
Parietal Bone ◽  
Female Rats ◽  
Sprague Dawley ◽  
Post Surgery ◽  
Group A ◽  
The Mean ◽  
Group B ◽  
The Right

Abstract Background This study aims at determining the biological effect of 75/25 w/w nano-hydroxyapatite/chitosan (nHAp/CS) scaffolds on bone regeneration, in terms of fraction of bone regeneration (FBR), total number of osteocytes (Ost), and osteocyte cell density (CD), as well as its biodegradability. Methods Two critical-size defects (CSDs) were bilaterally trephined in the parietal bone of 36 adult Sprague-Dawley rats (18 males and 18 females); the left remained empty (group A), while the right CSD was filled with nHAp/CS scaffold (group B). Two female rats died postoperatively. Twelve, 11, and 11 rats were euthanized at 2, 4, and 8 weeks post-surgery, respectively. Subsequently, 34 specimens were resected containing both CSDs. Histological and histomorphometric analyses were performed to determine the FBR, calculated as [the sum of areas of newly formed bone in lateral and central regions of interest (ROIs)]/area of the original defect, as well as the Ost and the CD (Ost/mm2) in each ROI of both groups (A and B). Moreover, biodegradability of the nHAp/CS scaffolds was estimated via the surface area of the biomaterial (BmA) in the 2nd, 4th, and 8th week post-surgery. Results The FBR of group B increased significantly from 2nd to 8th week compared to group A (P = 0.009). Both the mean CD and the mean Ost values of group B increased compared to group A (P = 0.004 and P < 0.05 respectively). Moreover, the mean value of BmA decreased from 2nd to 8th week (P = 0.001). Conclusions Based on histological and histomorphometric results, we support that 75/25 w/w nHAp/CS scaffolds provide an effective space for new bone formation.

scholarly journals Survival and echocardiographic evaluation of dogs with idiopathic dilated cardiomyopathy treated with carvedilol

2010 ◽  
Vol 62 (3) ◽  
pp. 555-563 ◽  
Author(s):  
E.C. Soares ◽  
G.G. Pereira ◽  
L.C. Petrus ◽  
M. Leomil Neto ◽  
F.L. Yamaki ◽  
...  
Keyword(s):  
Dilated Cardiomyopathy ◽  
Ventricular Remodeling ◽  
Left Ventricular ◽  
Idiopathic Dilated Cardiomyopathy ◽  
P Value ◽  
Echocardiographic Evaluation ◽  
Before And After ◽  
Group A ◽  
The Stability ◽  
Group B

Sixty dogs with idiopathic dilated cardiomyopathy were randomly treated with traditional therapy - digitalis, diuretics, angiotensin-converting inhibitors - (group A) or treated with these drugs plus carvedilol (group B). Echocardiographic variables were measured before and after 3, 13, 26, and 52 weeks of treatment or until death. Comparisons between groups and time were performed. No significant differences between groups were found in the most of the echocardiographic variables. The left ventricular end-systolic diameter indexed to body surface area (LVESDi) increased significantly in the group A dogs compared to the group B animals. The survival of groups A and B dogs were not different (P-value=0.1137). In conclusion, the stability of the LVESDi observed in the group treated with carvedilol may represent the beneficial effect over the ventricular remodeling.

scholarly journals Effects of Swiss ball exercise and Pilates exercise on core muscle strengthening in college cricketers

Biomedicine ◽  
2020 ◽  
Vol 40 (3) ◽  
pp. 377-380
Author(s):  
K. Kamatchi ◽  
B. Arun ◽  
G. Tharani ◽  
G. Yuvarani ◽  
G. Vaishnavi ◽  
...  
Keyword(s):  
Mean Value ◽  
Terminal Segment ◽  
Core Stability ◽  
Lower Limbs ◽  
Age Group ◽  
Mean Values ◽  
Muscle Strengthening ◽  
Group A ◽  
Group B ◽  
Swiss Ball

Introduction and Aim: Cricket is one of the most popular game in India played by men and women of all ages. Core stability is defined as the ability to control the position and movement of the trunk over the pelvis to allow optimum production, transfer and control of force and movement to the terminal segment. Major muscles involved are pelvic floor muscles, Transverse abdominis, multifidus, internal and external obliques, and rectus abdominis. Core is used to stabilize the thorax and the pelvis during dynamic movement. The study helps to compare the effectiveness of Swiss ball exercise and Pilates exercise on gaining core muscle strength. The aim of the study is to compare the effect of Swiss ball exercise and Pilates exercise on core muscle strengthening in college cricketers. Materials and Methods: The design of the study is comparative type. The study was carried out in faculty of Physiotherapy, Dr.M.G.R. Educational and Research Institute. The study sample of 30 male college cricketers between the age group of 18 to 25 years are included in the study. Individuals with associated neuromuscular conditions, any injuries to lower limbs and any spinal injuries have been excluded in the study. Swiss ball and Pilates mat are the materials used. Sphygmomanometer is the outcome measure.30 male individuals between the age group of 18 to 25 years were divided into two groups, group A and group B. Individuals in the group A (n=15) received the Swiss ball exercise and group B (n=15) received Pilates exercise for 4 session/ week for 6 weeks. Results: On comparing the mean values of group A and group B on double leg lowering test (DLLT), it shows significant decrease in the post test mean values but (group B- Pilates exercise) shows (30.60) which has the lower mean value is more effective than (group A- Swiss ball exercise) (46.80) at P ? 0.001. Hence, null hypothesis is rejected. Conclusion: The study concluded that both the group was effective but while comparing Pilates exercise showed the potential treatment option than swiss ball exercise. Hence, Pilates exercise was effective on core muscle strengthening in college cricketers. Keywords: Swiss ball; Pilates mat; core muscle; sphygmomanometer.

scholarly journals Comparison of Fracture Resistance of Teeth Presenting non-carious Cervical Lesions, Restored with Different Composite Materials

2020 ◽  
Vol 57 (1) ◽  
pp. 299-305
Author(s):  
Ruxandra Margarit ◽  
Livia Alice Tanasescu ◽  
Dana Bodnar ◽  
Camelia Gabriela Ion ◽  
Mihai Burlibasa ◽  
...  
Keyword(s):  
Composite Materials ◽  
Fracture Resistance ◽  
Mean Value ◽  
P Value ◽  
Cervical Lesions ◽  
Nano Composite ◽  
Commercial Grade ◽  
Different Types ◽  
Group A ◽  
Group B

The aim of our study was to compare the fracture resistance of teeth presenting non-carious cervical lesions restored with different types of esthetic composite materials. 20 extracted unspoiled maxillary first molars were mechanically cleaned and immersed in saline solution containing 0.1% thymol at 4�C for a period of 48 hours. Cervical cavities with a cervical-occlusal diameter of 2 mm and a mesial-distal diameter of 3mm were filled with ormocer, flow nano-composite, nano-composite and compomer. Fracture resistance was tested with a universal loading machine (Lloyd Instruments), with a maximum force of 5 kN and a crosshead speed of 1.0 mm/min; the authors used NEXYGEN Data Analysis Software and ANOVA method. For the group A (commercial grade ormocer), the smallest load that determined the sample failure was 650 N and the highest load was 1050 N, the mean value being 858 N � 150.89 N. For the group B (commercial grade flow nano-composite), the smallest load is 530 N, the highest load is 800 N, mean value being 654 N � 112.6 N. For the group C (commercial grade nano-composite), the smallest load is 680 N, the highest load is 1200 N, mean value being 926 N � 209.35 N. For the group D (commercial grade compomer), the smallest load is 1100 N, highest load is 1250N, mean value being 1180 N � 62.04 N. A p value of 0.000311 (p[0.05) shows that there are significant differences between the four groups. Conclusions. The best fracture resistance of teeth presenting non-carious cervical lesions, restored with different types of esthetic composite materials is assured by the compomer, followed by the nano-composite, which proved to be superior to ormocer. The flow nano-composite gives the lowest fracture resistance.

the value of patient hydration prior to bone scintigraphy

2003 ◽  
Vol 5 (1) ◽  
pp. 13-18
Author(s):  
s. m. stace ◽  
s. m. huggett ◽  
b. k. denton ◽  
a. m. harries
Keyword(s):  
Soft Tissue ◽  
Bone Scintigraphy ◽  
Statistical Difference ◽  
Mean Value ◽  
Regions Of Interest ◽  
Femoral Diaphysis ◽  
Post Injection ◽  
Group A ◽  
The Mean ◽  
Group B

the aim of this study was to establish whether hydration prior to radiopharmaceutical injection, in addition to post injection hydration, contributed any value to image quality during bone scintigraphy. two hundred patients referred for bone imaging over a four month period were randomised into two groups. group a was issued with instructions to hydrate pre and post injection, and group b was only advised to hydrate between injection and scan. equal regions of interest (roi) were then drawn on each image: firstly over the femoral diaphysis, and secondly over the contra-lateral adductor area. the total number of gamma counts from the bone roi and the soft tissue roi was then expressed as a ratio, and a mean value for each group was established.the mean ratio for group a was found to be 2.25, and for group b 2.30. a t test of variance confirmed that there was no statistical difference between the ratios of the groups (t = 50.272, n = 5100, p = 50.618). it was concluded that hydration levels prior to bone scintigraphy injection, where it is preserved post injection, have no significant effect on the bone-soft tissue (b:st) ratio in the image.

Plantar Hyperhidrosis: The Efficacy of Iontophoresis with Tap water, Glycopyrronium Bromide and Indomethacin

2021 ◽  
Vol 11 (5) ◽  
Author(s):  
Senthilnathan Prof.Dr.C.V. ◽  
Vaishnavi G. ◽  
Keerthana G. ◽  
NandhaKumar S. ◽  
Kotteeswaran Prof.Dr.
Keyword(s):  
Tap Water ◽  
Psychological Trauma ◽  
Mean Value ◽  
The Body ◽  
Negative Ion ◽  
Unknown Etiology ◽  
Mean Values ◽  
Glycopyrronium Bromide ◽  
Group A ◽  
Group B

Hyperhidrosis is an excessive production of sweat more than the physiological amount necessary to maintain thermal homeostasis. Primary focal hyperhidrosis is a disorder of unknown etiology, causing excessive, bilateral, symmetrical sweating on the soles of the foot is called plantar hyperhidrosis. The condition results not only in physical impairment, but also interferes with professional and social life. Although not life-threatening, it is very uncomfortable and cause embarrassment and psychological trauma. Iontophoresis is a helpful method, which includes the presentation of particles into the body tissue through the skin. The essential principle is to place the ion particles under an electrode with the same charge, i.e. negative ion placed under cathode and positive ion placed under anode. This complete process is also known as “technique of ion transfer” into the body tissues by using electrical current as a driving force. It is a comparative study with pre and post intervention. 30 subjects with plantar hyperhidrosis were selected based on the inclusion criteria. The study duration was for about 4 weeks30 subjects of age group between 15 – 25 years with idiopathic plantar hyperhidrosis of both male and female subjects were included in this study. Subjects with cardiac and respiratory disorders, pregnant or lactating, any cuts, abrasions, eczema or infections on plantar aspect, metal implants like pacemakers, Hypersensitivity to the active substance were excluded. The subjects were divided into 3 group Group A treated with iontophoresis using tap water alone. Group B were treated with iontophoresis using tap water along with 3%-5% of anticholinergic drug, glycopyrronium bromide solution. Group C were treated with iontophoresis using tap water along with 1% of indomethacin (NSAID). The result of this study shows that there were significant changes in outcome measures. On comparing Mean values of Group A, Group B & Group C on Minor test (Starch - Iodine Test) tap Water along with Glycopyrronium Bromide (Group B) shows 1.60 which has the Lower Mean value is effective than Group A and Group C .On comparing Mean values of Group A, Group B & Group C on Visual Analog Scale score tap Water along with Glycopyrronium Bromide (Group B) shows 3.80 which has the Lower Mean value is effective than Group A and Group C. On comparing Mean values of Group A, Group B & Group C on Hyperhidrosis Disease Severity Scale tap Water along with Glycopyrronium Bromide (Group B) shows 1.40 which has the Lower Mean value is effective than Group A and Group C. On comparing all the three groups, Group B shows better result than Group C and Group A in outcome measure. This study concluded that Tap water along with glycopyrronium bromide reduces the excessive sweating and decrease the sweating symptoms in subjects with plantar hyperhidrosis.

The Effect of Gongronema Latifolum (Utazi) on Some Haematological Parameters of Rabbit

2020 ◽  
Author(s):  
Obeagu Emmanuel Ifeanyi
Keyword(s):  
Mean Value ◽  
Control Group ◽  
Mean Values ◽  
Platelet Counts ◽  
Group A ◽  
The Mean ◽  
Group B ◽  
Differential White Blood Cell ◽  
Group D ◽  
Gongronema Latifolium

The hematological features of Gongronema latifolium, aqueous leaves extract was evaluated using standard methods. After 10 days of consecutive infusions into 9 experimental animals (rabbits). The rabbits were monitored and the following parameters determined; hemoglobin (HB), PCV, Platelet, WBC, Differential White Blood Cell. The Rabbits were grouped into 4, one consisting of control (group A), group B was fed with 0.5 mg/kg, group C with 1.0 mg/kg, and Group D with 1.5mg/kg of the aqueous extract of Gongronemalatifolium. The mean values obtained for hemoglobin estimation for the control group is 5.9 ± 4.1 g/dl, 9.1 ± 2.9 g/dl for group B 10.2 ± 1.8 g/dl for group C and 12.8 ± 0.1 g/dl for group D with no significant increase on the PCV estimation, the mean value for the control (group A) is 17.7 ± 12.3%, 27.3 ± 8.7% for group B, group C (30.6 ± 5.4%) and D (28.4 ± 0.3) show increase that statistically significant (p > 0.01). the platelet counts of group C (600 ± 0 x 109/L) and D(600 ± 0 x 109/L) show significant increase (p > 0.01) when compared with the control (600 ± 00). But the platelet value of group B (550 ± 50 x 109/L) shows no difference. No significant changes were observed in the White Blood Counts of the test groups B (3.5 ± 0.5 x 109/L), C (1.9 + 2.1 x 109/L) and D(3.6 ± 0.4) when compared with the control group (2.9 ± 1.9). The values obtained from the differential White Blood Counts (Neutrophils, Lymphocytes, Eosinophils and Monocytes) were not significant. Therefore, Gongronemalatifolium, when properly taken as a nutritional diet, causes beneficial changes on hemoglobin, packed cell volumes and platelet counts of consumers.

Comparison of Three Different Screw Trajectories in Osteoporotic Vertebrae: A Biomechanical Investigation

2020 ◽  
Author(s):  
Jan-Sven Jarvers ◽  
Stefan Schleifenbaum ◽  
Christian Pfeifle ◽  
Christoph Oefner ◽  
Melanie Edel ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Fatigue Behavior ◽  
Fixation Strength ◽  
Patient Specific ◽  
Promising Alternative ◽  
Cortical Bone Trajectory ◽  
Pull Out ◽  
Group A ◽  
The Mean ◽  
Group B

Abstract Background: Pedicle screw insertion in osteoporotic patients is challenging. Achieving more screw-cortical bone purchase and invasiveness minimization, the cortical bone trajectory and the midline cortical techniques represent alternatives to traditional pedicle screws. This study compares the fatigue behavior and fixation strength of the cement-augmented traditional trajectory (TT), the cortical bone trajectory (CBT) and the midline cortical (MC). Methods: Ten human cadaveric spine specimens (L1 - L5) were examined. The average age was 86.3 ± 7.2 years. CT scans were provided for preoperative planning. CBT and MC were implanted by using the patient-specific 3D-printed placement guide (MySpine®, Medacta International), TT were implanted freehand. All 10 cadaveric specimens were randomized to group A (CBT vs. MC) or group B (MC vs. TT). Each screw was loaded for 10,000 cycles. The failure criterion was doubling of the initial screw displacement resulting from the compressive force (60 N) at the first cycle, the stop criterion as a doubling of the initial screw displacement. After dynamic testing, screws were pulled out axially at 5 mm/min to determine their remaining fixation strength. Results: The mean pull-out forces did not differ significantly. Concerning the fatigue performance, only one out of ten MC of group A failed prematurely due to loosening after 1,500 cycles (L3). Five CBT already loosened during the first 500 cycles. The mean displacement was always lower in the MC. In group B, all TT showed no signs of failure or loosening. Three MC failed already after 26 cycles, 1,510 cycles, and 2,144 cycles, respectively. The TT showed always a lower mean displacement. In the subsequent pull-out tests, the remaining mean fixation strength of the MC (449.6 ± 298.9 N) was slightly higher compared to the mean pull-out force of the CBT (401.2 ± 261.4 N). However, MC (714.5 ± 488.0 N) were inferior to TT (990.2 ± 451.9 N).Conclusion: The current study demonstrated that cement-augmented TT have best fatigue and pull-out characteristics in osteoporotic lumbar vertebrae, followed by the MC and CBT. MC represent a promising alternative in osteoporotic bone if cement augmentation should be avoided. Using the patient-specific guide contributes to improve screws’ biomechanical properties.

scholarly journals Reduction of arrhythmias in primary hyperparathyroidism, by parathyroidectomy, evaluated with 24-h ECG monitoring

2018 ◽  
Vol 179 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Jessica Pepe ◽  
Cristiana Cipriani ◽  
Mario Curione ◽  
Federica Biamonte ◽  
Luciano Colangelo ◽  
...  
Keyword(s):  
Primary Hyperparathyroidism ◽  
Mineral Metabolism ◽  
Randomized Study ◽  
Density Measurement ◽  
Mean Value ◽  
Ecg Monitoring ◽  
Mineral Density ◽  
Group A ◽  
Group B ◽  
The Impact

ObjectiveHypercalcemia may induce arrhythmias. There are no data on the prevalence of arrhythmias in primary hyperparathyroidism (PHPT) in daily life. Aim of the study was to investigate both the prevalence of arrhythmias in patients with PHPT compared to controls and the impact of parathyroidectomy, evaluated by 24-h electrocardiogram (ECG) monitoring.DesignThis is a randomized study.MethodsTwenty-six postmenopausal women with PHPT and 26 controls were enrolled. PHPT patients were randomized to two groups: 13 underwent parathyroidectomy (Group A) and 13 were followed up conservatively (Group B). After 6 months, patients were studied again. Each patient underwent mineral metabolism biochemical evaluation, bone mineral density measurement, standard ECG and 24-h ECG monitoring.ResultsPHPT patients showed higher calcium and parathyroid hormone compared to controls and a higher prevalence of both supraventricular (SVBPs) and ventricular premature beats (VPBs) during 24-h ECG monitoring. Groups A and B showed no differences in mean baseline biochemical values and ECG parameters. Mean value of QTc in PHPT groups was in the normal range at baseline, but significantly shorter than controls. A negative correlation was found between QTc and ionized calcium levels (r = −0.48,P < 0.05). After parathyroidectomy, Group A had a significant reduction in SVPBs and VPBs compared to baseline and restored normal QTc. Group B showed no significant changes after a 6-month period.ConclusionsThe increased prevalence of SVPBs and VPBs is significantly reduced by parathyroidectomy, and it is mainly related to the short QTc caused by hypercalcemia.

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