scholarly journals Adhesion Assessment Between Composites Using Three Different Protocols

2020 ◽  
Vol 57 (1) ◽  
pp. 236-243
Author(s):  
Raul Ghiurca ◽  
Smaranda Buduru ◽  
Marius Bud ◽  
Rares Buduru ◽  
Cristian Culcitchi ◽  
...  

The main purpose of this study is to evaluate three different adhesiveprotocols between two composites. We used 60 composite specimens (Kerr�s Herculite XRV Ultra), randomly divided into 3 equal experimental groups, in which adhesion was performed using different protocols: Group 1 (n= 20) surface preparation with a 1.4 mm cylindrical diamond bur (Kerr Dental, FG503C-5) + etch and rinse technique in 2 steps; Group 2 (n= 20) surface preparation with a 1.4 mm cylindrical diamond bur (Kerr Dental, FG503C-5) + Al2O3 (Zhermack Dental) sandblasting + etch and rinse technique in 2 steps; Group 3 (n= 20) surface preparation with a 1.4 mm cylindrical diamond bur (Kerr Dental, FG503C-5) + glycine (EMS) sandblasting + etch and rinse technique in 2 steps. Adhesion assessment was made by measuring tensile strength with a universal testing machine, the INSTRON 3343 (Instron�, USA). At the end, the results were statistically compared using the ANOVA test. Group 3 (glycine protocol) had the greatest values in terms of tensile strength.

2015 ◽  
Vol 20 (4) ◽  
pp. 57-62 ◽  
Author(s):  
Francilena Maria Campos Santos Dias ◽  
Célia Regina Maio Pinzan-Vercelino ◽  
Rudys Rodolfo de Jesus Tavares ◽  
Júlio de Araújo Gurgel ◽  
Fausto Silva Bramante ◽  
...  

OBJECTIVE: To compare shear bond strength of different direct bonding techniques of orthodontic brackets to acrylic resin surfaces.METHODS: The sample comprised 64 discs of chemically activated acrylic resin (CAAR) randomly divided into four groups: discs in group 1 were bonded by means of light-cured composite resin (conventional adhesive); discs in group 2 had surfaces roughened with a diamond bur followed by conventional direct bonding by means of light-cured composite resin; discs in group 3 were bonded by means of CAAR (alternative adhesive); and discs in group 4 had surfaces roughened with a diamond bur followed by direct bonding by means of CAAR. Shear bond strength values were determined after 24 hours by means of a universal testing machine at a speed of 0.5 mm/min, and compared by analysis of variance followed by post-hoc Tukey test. Adhesive remnant index (ARI) was measured and compared among groups by means of Kruskal-Wallis and Dunn tests.RESULTS: Groups 3 and 4 had significantly greater shear bond strength values in comparison to groups 1 and 2. Groups 3 and 4 yielded similar results. Group 2 showed better results when compared to group 1. In ARI analyses, groups 1 and 2 predominantly exhibited a score equal to 0, whereas groups 3 and 4 predominantly exhibited a score equal to 3.CONCLUSIONS: Direct bonding of brackets to acrylic resin surfaces using CAAR yielded better results than light-cured composite resin. Surface preparation with diamond bur only increased shear bond strength in group 2.


Author(s):  
Jane Park ◽  
Danielle Dugat ◽  
Mark Rochat ◽  
Hall Griffin ◽  
Mark E. Payton

Abstract Objective The aim of this study was to evaluate the effect of bidirectional insertion on axial pullout strength of tapered run out (TRO), traditional negative profile (TNP) and positive profile (PP) pins. Study Design Cadaveric adult canine tibiae were harvested. Tapered run out pins (Group 1) were inserted unidirectionally to the desired position; bidirectionally past the desired position, then withdrawn to the desired position (Group 2); and bidirectionally as described for Group 2, repeated twice (Group 3). Traditional negative profile pins (Group 4–6) and PP pins (Group 9–11) were placed in the same manner. Tapered run out (Group 7), TNP (Group 8) and PP pins (Group 12) were driven unidirectionally such that the shaft of the pin violated the cis-cortex. A servohydraulic testing machine extracted the pins and measured axial peak pullout strength. Results Positive profile pins had significantly greater pullout strength than TRO and TNP pins placed unidirectionally to the desired position. Method of insertion had no effect on peak pullout strength of TNP pins. TRO and PP pins inserted unidirectionally to the desired position had significantly greater peak pullout strengths than insertion bidirectionally or if the shaft of the pin violated the cis-cortex. Conclusion The authors recommend that pins used for external skeletal fixation should be placed unidirectionally to the desired position with fluoroscopic guidance, intra-operative depth gauge measurements or measurements from preoperative radiographs. Repositioning pins results in loss of peak pullout strength with TRO and PP pins.


2017 ◽  
Vol 22 (4) ◽  
pp. 47-52 ◽  
Author(s):  
Marina Cumerlato ◽  
Eduardo Martinelli de Lima ◽  
Leandro Berni Osorio ◽  
Eduardo Gonçalves Mota ◽  
Luciane Macedo de Menezes ◽  
...  

ABSTRACT Objective: The aim of this in vitro study was to evaluate and compare the effects of grinding, drilling, sandblasting, and ageing prefabricated teeth (PfT) on the shear bond strength (SBS) of orthodontic brackets, as well as the effects of surface treatments on the adhesive remnant index (ARI). Methods: One-hundred-ninety-two PfT were divided into four groups (n = 48): Group 1, no surface treatment was done; Group 2, grinding was performed with a cylindrical diamond bur; Group 3, two drillings were done with a spherical diamond bur; Group 4, sandblasting was performed with 50-µm aluminum oxide. Before the experiment, half of the samples stayed immersed in distilled water at 37oC for 90 days. Brackets were bonded with Transbond XT and shear strength tests were carried out using a universal testing machine. SBS were compared by surface treatment and by ageing with two-way ANOVA, followed by Tukey’s test. ARI scores were compared between surface treatments with Kruskal-Wallis test followed by Dunn’s test. Results: Surface treatments on PfT enhanced SBS of brackets (p< 0.01), result not observed with ageing (p= 0.45). Groups II, III, and IV showed higher SBS and greater ARI than the Group 1 (p< 0.05). SBS was greater in the groups 3 and 4 (drilling, sandblasting) than in the Group 2 (grinding) (p< 0.05). SBS and ARI showed a positive correlation (Spearman’s R2= 0.57; p< 0.05). Conclusion: Surface treatment on PfT enhanced SBS of brackets, however ageing did not show any relevance. Sandblasting and drilling showed greater SBS than grinding. There was a positive correlation between SBS and ARI.


2021 ◽  
Vol 37 (3) ◽  
Author(s):  
Khulud A Al Aali ◽  
Saad Alresayes ◽  
Aasem M Alhenaki ◽  
Fahim Vohra ◽  
Tariq Abduljabbar

Objectives: To evaluate the effect of time and hydration (ageing) on flexural strength of yttrium-stabilized zirconia polycrystals (Y-TZP) zirconia fabricated from three different materials. Methods: This in-vitro study was performed from June to September 2019. Y-TZP bars, measuring 2 x 3 x 20 mm were prepared and sintered from three different materials, Group-1: LAVA™ Zirconia (3M™ ESPE, US) (control) Group-2: Vita In-Ceram YZ (VITA, Germany) and Group-3: Aadva™ Zirconia (Zr) (GC Advanced technologies Inc.). 30 zirconia bars per group were prepared using sectioning of blocks with isomet saw. Followed by sintering in furnaces for recommended temperature cycles. One side of bars were polished and beveled for flexural testing. Groups of specimens were divided into subgroups of 3 (n=10) based on the ageing (distilled water in the incubator at 37ºC) durations (48 Hrs and two and half years). Ten specimens in each material groups were not aged (controls). Samples were exposed to a static force in a three-point bend test using a universal instron-testing machine until fracture. Scanning electron microscopic assessment was performed for fractured specimens for ageing. Data was analyzed using ANOVA and Tukey post hoc test. Results: The mean flexural strength at baseline for Group-1: LAVA™ Zirconia, group (632.7 ± 136.5 MPa) 2: Vita In-Ceram YZ (1036.3 ± 229.6 MPa), and Group-3: Aadva™ Zirconia (1171.3 ± 266.3 MPa) were significantly different. Group-2 and Group-3 specimens showed higher strength compared to Group-1 specimens, irrespective of the ageing duration (p<0.05). Analysis of pooled data for flexural strength for materials by aging period (baseline, after 48 hours and after 2 and ½ years) showed that there was significant reduction of strength with increasing duration (p<0.05). Conclusions: Y-TZP showed variations in flexural strength depending on the material type. Ageing duration exhibited significant influence on the flexural strength of Y-TZP when comparing no ageing to two and half years. Vita In-Ceram YZ and Aadva Zirconia (Zr) showed higher and clinically acceptable flexural strength outcomes. doi: https://doi.org/10.12669/pjms.37.3.3996 How to cite this:Al-Aali KA, Alresayes S, Alhenaki AM, Vohra F, Abduljabbar T. Influence of time and hydration (ageing) on flexural strength of Yttrium stabilized Zirconia polycrystals (Y-TZP) fabricated with different CAD-CAM Systems. Pak J Med Sci. 2021;37(3):---------.   doi: https://doi.org/10.12669/pjms.37.3.3996 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


2013 ◽  
Vol 42 (6) ◽  
pp. 449-453
Author(s):  
Matheus Melo Pithon ◽  
Érica Luiza Santana Moreira Sousa ◽  
Davi Novaes Ladeia Fogaça ◽  
William Soares da Silva ◽  
Luciano Brito Rodrigues ◽  
...  

OBJECTIVE: Evaluate resistance of Hawley retainers in three different acrylic configurations in order to evaluate if its format or the addition of internal wire interferes in its resistance. MATERIAL AND METHOD: 45 Hawley retainers were fabricated, divided into three groups (n = 15): Group 1 - acrylic covering the entire hard palate, Group 2 - plate with relief at the deepest region of the palate, leaving it with a "U" conformation and Group 3 - similar to Group 2, with the addition of 0.7mm wire 2cm internally of the acrylic at the region of the palatine ridges. The compressive strength was tested in a universal mechanical testing machine (Stable Microsystems, London, United Kingdom), measuring the applied force until plate rupture occurred. The differences between the formats being compared by the Kruskal-Wallis test. The significance level was set at 5% (α = 0.05). RESULT: Group 1 showed the highest resistance, with a mean of about five times higher than Group 2 and three times higher than Group 3. CONCLUSION: acrylic reduction in dental retainer plates is directly related to the reduction of its compressive strength, the inclusion of orthodontic wire inside the acrylic increases the resistance of the plate, being a good alternative when more comfort is wanted for the patient without loss of the mechanical characteristics of the dental retainers.


2007 ◽  
Vol 330-332 ◽  
pp. 1361-1364 ◽  
Author(s):  
Sang Bae Lee ◽  
Jung Y. Cha ◽  
Doug Youn Lee ◽  
Kyeong Jun Park ◽  
Kyoung Nam Kim ◽  
...  

In this study, the effect of cyanoacrylate-based β-tricalcium phosphate (β-TCP) on pullout strength of orthodontic mini-screw was evaluated. New cements were prepared by mixing Histoacryl® (n-butyl cyanoacrylate) and acid-treated β-tricalcium phosphate. The ratios of β-TCP to Histoacryl® were 0, 0.5, 1.0, and 2.0. Artificial bone blocks were used as a substrate for the miniscrew implantation. The test groups were divided into three groups (one solid bone block [group 1] and a bone block with a 0.9 mm hole [group 2], and a bone block with a 2.5 mm hole [group 3]). And each group was divided into subgroups according to cement usage and non-usage. The used artificial bone density was 0.64g/cm2. Pullout strengths were determined using a universal testing machine. Statistical analysis was performed using the SPSS 9.0 for Windows program. Paired samples t-tests and ANOVA were used with p<0.05. The maximum pullout strengths were 295.9 ± 3.8 N for group 1, 261.1±15.0 N for group 2, and 273.2±20.0 N for group 3. In group 1 and 2, the pullout strength in the subgroup using cement was higher than that of the subgroup of not using cement (p<0.05). In group 3, the pullout strength in the subgroups using cyanoacrylate-based β- TCP cement was higher than that of the subgroup using conventional glass ionomer cement (GC Fuji-I, GC Co., Tokyo, Japan) (p<0.05). These results indicate that our β-TCP/Histoacryl® cements have the potential to enhance pullout strength of the orthodontic mini-screw.


2020 ◽  
Vol 7 (2) ◽  
pp. 353
Author(s):  
Hüseyin Alakuş ◽  
Mustafa Göksu

Background: In this study, following the Bogota bag closure of abdominal wall defects created in a rat peritonitis model, the short-term efficacy of polypropylene (PP) mesh (Prolene®, Ethicon), PP Mesh+Seprafilm®, polytetrafluoroethylene (PTFE) mesh [Infinit® Mesh (Gore)] and expanded PTFE (ePTFE) [Dualmesh®plus(Gore)] in the permanent repair of the defects was investigated.Methods: 64 rats were used. The rats were randomized into four groups, each consisting of 16 subjects: PP mesh (Group 1), PP mesh+Seprafilm (Group 2), PTFE mesh (Group 3), and ePTFE mesh (Group 4). Laparotomy was performed and abdominal wall defects were created. Contamination of the peritoneal cavity was induced, and closure was undertaken using a Bogota bag. After three days, the Bogota bag was removed, and materials were placed. At the end of the follow-up period, the rats were sacrificed. Mortality, grade of adhesion, surgical site infection (SSI), and tensile strength were evaluated.Results: Mortality was calculated as 6.3%, 50%, 25%, and 0% for Groups 1, 2, 3, and 4, respectively (p=0.002). Adhesion was observed at a rate of 61.1% in Group 1 and 38.9% in Group 2 (p=0.621). There was no adhesion in Groups 3 and 4 (p=0.001). The rate of SSI was 68.8% in Group 1, %75% in Group 2, and 100% in Groups 3 and 4 (p=0.022). Tensile strength was 2196±193.6 g/cm in Group 1 and 1906±142.1 g/cm in Group 2 (p=0.258).Conclusions: We argue that PP mesh is a suitable prosthesis for the permanent repair of contaminated abdominal wall defects despite the increased adhesion risk.


Author(s):  
Dennis, Amaechi ◽  
E. O. Udosen ◽  
V. S. Ekam ◽  
I. P. Ekpe

Aim: This study aims to determine the effects of methanolic root extract of Holarrehna floribunda on the level of some serum sex hormones, follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, estradiol, progesterone and lipid profile in Wistar rats.   Materials and Methods: Twenty- four male and female Wistar rats (150-250 g body weight) were randomly assigned into 4 groups of 6 rats each. Group 1 (control male) took normal rat chow and drinking water. Group 2 (control female) took normal rat chow and drinking water, Group 3(Male test group), was administered with 200 mg/kg of Holarrehna floribunda extract, Group 4(Female test group), was administered with 200 mg/kg of Holarrehna floribunda. The feeding regimens lasted for 5weeks. Results: The values for the lipid profile shows CHOL in Group 1 and Group 3 were 4.02±0.41 mmol/l  and 5.75±0.09 mmol/l, Group 2 and Group 4 were 3.87±0.22 mmol/l  and 5.80±0.10 mmol/l  respectively, TRIG  for Group 1 and Group 3 were 1.30±0.05 mmol/l  and 2.11±0.15 mmol/l  for Groups 2 and 4 were 1.15±0.03 mmol/l  and (2.10±0.12 mmol/l,HDL-C for Groups 1 and 3 were 30.01±0.82 mg/dL  and 39.88± 1.24mg/dL,for Groups 2 and 4 were 29.98± 0.77 mg/dL  and 38.20± 1.83 mg/dL, LDL-C for Groups 1 and 3 were 2.26±0.37 mmol/L  and 4.17±0.35 mmol/L respectively, for Groups 2 and 4 were 3.27±0.47 mmol/L  and 4.06±0.21 mmol/L  respectively, shows significant increase(p<0.05) in HDL-C (mg/dL) in Groups 1,2,3 and 4.The values obtained showed significant increase (p<0.05) in HDL-C (mg/dL) in Groups 1,2,3and 4The serum concentrations of FSH, Estradiol, LH and progesterone in the control Group 2 were 0.38 ±0.07mIU/mL, 7.83±0.35 mIU/mL, 15.50±0.15 Pg/mL and 0.86±0.03 ng/mL respectively, and in test Group 4 were 0.77±0.04mIU/mL, 8.75±0.17 mIU/mL, 21.09±0.79 Pg/Ml 0.33±0.05 ng/mL. Follicle stimulating hormone levels was significantly higher (p<0.05) in test group compared with control. While in Group 1 and 3, the serum concentrations of FSH, LH, and testosterone in control Group 1 were (0.51 ±0.06) mIU/mL, (16.44±0.31) mIU/mL and (8.41±0.50) ng/mL respectively and in test Group 3 were 0.88±0.06 mIU/mL19.88±1.46mIU/mL and10.68±0.64 ng/mL, respectively. Conclusion: The extract improves the level of sex hormones in both the male and female rats.  which could enhance reproductive functions in normal rats and those with loss of reproductive function.


2003 ◽  
Vol 28 (5) ◽  
pp. 475-477 ◽  
Author(s):  
W. L. LAM ◽  
A. GARRIDO ◽  
J. VANDERMEULEN ◽  
M. J. FAGAN ◽  
P. R. W. STANLEY

We carried out a biomechanical study comparing tensile strength after using round-bodied or cutting needles for tendon repair. Swine tendons were repaired in three groups: Group 1 core suture repair only; group 2 core and circumferential suture repair; and group 3 isolated circumferential suture repair. The tendons were tested at longitudinal stress to failure at 5 mm/minute. No significant differences were found between the round-bodied and cutting needles in any group. Equal numbers in the core suture repair group failed by suture pullout when comparing cutting and round-bodied needles. We conclude that the choice of needle has no effect on the outcome of tendon repair if there is consistency of surgeon’s skill and experience.


2008 ◽  
Vol 33 (2) ◽  
pp. 166-169 ◽  
Author(s):  
JEFFREY E. BUDOFF ◽  
JOHN M. HICKS ◽  
GUSTAVO AYALA ◽  
BARRY S. KRAUSHAAR

The “Scratch Test” uses a sharp scalpel to scrape areas of suspected tendinosis in the management of lateral and medial epicondylitis. As claimed in the literature, this tissue is friable and peels off, whereas normal tendon does not. The purpose of this study was to determine whether, or not, the “Scratch Test” is able to differentiate between tendinosis and more normal adjacent tendon. Nineteen specimens from patients treated for tendinosis about the elbow were examined histologically. Three groups of specimens were compared: (1) grossly abnormal tendon, (2) tendon that was scraped out using the “Scratch Test” and (3) tendon that remained behind following the “Scratch Test”. There was no significant histological difference between visibly degenerated tendon (group 1) and that which was scraped out using the “Scratch Test” (group 2). There was, however, a significant histological difference between both these groups and the more normal tendon tissue that the “Scratch Test” left behind (group 3).


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