scholarly journals Influence of the degree of conversion and Bis-GMA residues of bulk fill resins on tissue toxicity in an subcutaneous model in rats

2020 ◽  
Vol 18 ◽  
pp. 228080002094733
Author(s):  
Liliana Barreto Girão ◽  
Joyce Ohana de Lima Martins ◽  
José Vitor Mota Lemos ◽  
Marcílio Rodrigues Pinto ◽  
Juliana Paiva Marques Lima Rolim ◽  
...  

Aim: To analyse the influence of the degree of conversion (DC) and light curing residues of different bulk fills (BFs) composites on the inflammatory profile in the subcutaneous tissue of rats. Materials and methods: Resin disks of BF-resins and their active conventional resins (CR; 3M®, Ivoclar®, and Kerr®) were light-cured at 2 mm (BF-superficial) and 4 mm (BF-deep) thicknesses and analyzed by infrared spectroscopy (FTIR; n = 3/group; DC and light curing residues). Then, the disks were implanted in four quadrants in the subcutaneous tissue of Wistar rats (sham, CR, BF-superficial and RF-deep), and after 7, 14, and 28 days, the animals ( n = 6/day) were euthanized for histological analysis of the intensity of the inflammatory process (scores 0–3). Kruskal–Wallis/Dunn and ANOVA/Bonferroni tests were used ( p < 0.05, Graph Pad Prism 5.0). Results: The DC of CR 3M® did not differ significantly compared to BF-superficial and BF-deep resins ( p = 0.235). The Ivoclar® and Kerr® resins showed a higher DC with CR and BF-superficial compared to the BF-deep ( p = 0.005 and p = 0.011, rctively). Kerr® resins showed a higher Bis-GMA/UDMA ratio, especially in BF-deep resin ( p < 0.05). 3M® and Ivoclar resins did not show high inflammation scores, but for Kerr® BF resins (superficial and deep), the inflammatory process was significantly higher than that in the CR and sham quadrants ( p = 0.031). Conclusion: The tissue inflammatory response after resin inoculation depends on the DC and light curing residues of Bis-GMA.

2018 ◽  
Vol 43 (6) ◽  
pp. E280-E287 ◽  
Author(s):  
JS Shim ◽  
SH Han ◽  
N Jha ◽  
ST Hwang ◽  
W Ahn ◽  
...  

SUMMARY This study investigated the effects of irradiance and exposure duration on dual-cured resin cements irradiated through ceramic restorative materials. A single light-curing unit was calibrated to three different irradiances (500, 1000, and 1500 mW/cm2) and irradiated to three different attenuating materials (transparent acryl, lithium disilicate, zirconia) with 1-mm thicknesses for 20 or 60 seconds. The changes in irradiance and temperature were measured with a radiometer (or digital thermometer) under the attenuating materials. The degree of conversion (DC) of dual-cure resin cement after irradiation at different irradiances and exposure durations was measured with Fourier transform near infrared spectroscopy. Two-way analysis of variance revealed that irradiance (p&lt;0.001) and exposure duration (p&lt;0.001) significantly affected temperature and DC. All groups showed higher DCs with increased exposure times (p&lt;0.05), but there were no statistically significant differences between the groups irradiated with 1000 mW/cm2 and 1500 mW/cm2 (p&gt;0.05). Higher-intensity irradiances yielded higher temperatures (p&lt;0.05), but exposure time did not affect temperature when materials were irradiated at 500 mW/cm2 (p&gt;0.05).


Author(s):  
Carlos Alberto Lima UTRABO ◽  
Nicolau Gregori CZECZKO ◽  
Cesar Roberto BUSATO ◽  
Mário Rodrigues MONTEMÓR-NETTO ◽  
Leandro LIPINSKI ◽  
...  

ABSTRACT Background: In the definition of the mesh to be used to correct hernias, porosity, amount of absorbable material and polypropylene should be considered in the different stages of healing process. Aim: To evaluate the inflammatory reaction in the use of macro and microporous meshes of high and low weight in the repair of defects in the abdominal wall of rats. Methods: Ninety Wistar rats (Rattus norvegicus albinus) were used. The animals were submitted to similar surgical procedures, with lesion of the ventral abdominal wall, maintaining the integrity of the parietal peritoneum and correction using the studied meshes (Prolene®, Ultrapro® and Bard Soft®). Euthanasia was performed at 30, 60 and 120 days after surgery. The abdominal wall segments were submitted to histological analysis using H&E, Masson’s trichrome, immunohistochemistry, picrosirius red and tensiometric evaluation. Results: On the 120th day, the tensiometric analysis was superior with Ultrapro® macroporous mesh. The inflammatory process score showed a significant prevalence of subacute process at the beginning and at the end of the study. Microporous meshes showed block encapsulation and in macroporous predominance of filamentous encapsulation. Conclusion: The Ultrapro® mesh showed better performance than the others in healing process of the abdominal wall.


Author(s):  
Adriana de Souza RÓS ◽  
Carlos Henrique Marques dos SANTOS ◽  
Doroty Mesquita DOURADO ◽  
Moisés Soares da SILVA-NETO ◽  
Isabela CALDEIRA ◽  
...  

ABSTRACT Background: There is still a need for progress in the treatment of transsphincteric anal fistulae and the use of herbal medicines seems promising. Aim: To evaluate the efficacy of Stryphnodendron adstringens associated with fistulotomy and primary sphincteroplasty in the treatment of transsphincteric fistulae in rats. Methods: Thirty Wistar rats were used, which were submitted to transsphincteric fistulas with steel wire 0; after 30 days a treatment was performed according to the group. Group A (n=10) was submitted to fistulotomy; group B (n=10), fistulotomy followed by primary sphincteroplasty with “U” stitch with polyglactin 911 4-0; group C(n=10) , similar to group B, but with the interposition between the muscular stumps of hemostatic sponge soaked in Stryphnodendron adstringens extract. Euthanasia was performed after 14 days, resecting a segment of the anal canal for histological analysis, which aimed to evaluate the closure of the fistula, the area of separation of the muscle cables, the inflammatory process and the degree of fibrosis. Results: No animal had a remaining fistulous tract. About the spacing between the muscle cables, an average of 106.3 µm2 was observed in group A, 82.8 µm2 in group B and 51.8 µm2 in group C (p<0.05). There was no difference between the groups regarding the inflammatory process and, in relation to fibrosis, in group A there was a mean of 0.6, in group B 0.7 and in group C 0.2 (p<0.05). Conclusions: Stryphnodendron adstringens extract was able to allow less spacing between muscle cables in rats submitted to fistulotomy followed by primary sphincteroplasty, in addition to providing less local fibrosis.


2009 ◽  
Vol 20 (1) ◽  
pp. 17-21 ◽  
Author(s):  
Graziela Garrido Mori ◽  
Ivaldo Gomes de Moraes ◽  
Daniele Clapes Nunes ◽  
Lithiene Ribeiro Castilho ◽  
Wilson Roberto Poi

This aim of this study was to investigate the biocompatibility of two experimental acetazolamide (AZ)-based pastes in the subcutaneous tissue of rats. Both pastes contained AZ as the main component in similar concentration. The vehicle in experimental paste 1 was saline, while experimental paste 2 was prepared with propylene glycol. Sixty polyethylene tubes were sealed at one end with gutta-percha (GP), which served as a control. Half of the tubes were filled with paste 1 and half with paste 2. The tubes were implanted in the subcutaneous tissue of 15 rats, being 4 tubes for each animal. The animals were killed 7, 15 and 45 days after surgery and the specimens were processed in laboratory. The histological sections were stained with hematoxylin and eosin and were analyzed by light microscopy. Scores were assigned to level of inflammatory process: 1- none; 2- mild; 3- moderate; 4- severe. The data were analyzed statistically by the Kruskal-Wallis test (p≤0.05). Paste 1 produced an inflammatory process at 7 days. However, the intensity of this inflammation decreased with time and was nearly absent at 45 days. No statistically significant difference (p>0.05) was observed between the control (GP) and paste 1. However, paste 2 produced inflammatory response at all study periods and differed significantly (p<0.05) from the control. In conclusion, in the present study, the experimental AZ-based paste 1 was considered as biocompatible as the control matrial (GP), while experimental paste 2 was irritating to rat subcutaneous tissue.


2016 ◽  
Vol 19 (3) ◽  
pp. 59 ◽  
Author(s):  
Dayane Carvalho Ramos Salles Oliveira ◽  
Mateus Garcia Rocha ◽  
Eduardo José Souza-Júnior ◽  
Rodrigo Rocha-Maia ◽  
Regina Maria Puppin-Rontani ◽  
...  

<p><strong>Objective:</strong> To evaluate the effect of shade and curing mode on cure efficiency of two dual-cure resin cements. <strong>Material and Methods:</strong> Two shades (A2 and TRANS) of two different dual-cure resin cements (G-CEM, GC Dental and SET PP, SDI) were submitted to different curing modes: light curing through a 2 mm thick ceramic disc (IPS Empress Esthetic, A2, Ivoclar Vivadent) for 20 s (16 J/cm<sup>2</sup>), 40 s (32 J/cm<sup>2</sup>) or 80 s (64 J/cm<sup>2</sup>) performed immediately or with 1 or 5 min of delay. Fourier transform infrared spectroscopy (FT-IR) was used to evaluate the degree of conversion (DC) after 48 h. For the statistical analysis, data were submitted to three-way analysis of variance, followed by Tukey’s test for multiple comparisons (p=0.05). <strong>Results:</strong> Shade influenced DC (%) for the dual-cure resin cements tested (p=0.00001). TRANS shade showed lower DC (%) for both cements when there was no delay before light-curing (p=0.00001). Curing mode also influenced DC (%) for the dual-cure resin cements tested: radiant exposure greater than 32 J/cm<sup>2</sup> and delaying light-curing for 1 to 5 min increased the DC (%) for both dual-cure resin cements evaluated. <strong>Conclusions:</strong> One min delay prior to light curing improved the cure efficiency and may be a more clinically acceptable approach to increase the degree of conversion of dual-cure resin cements.</p>


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Bruno Rodrigues ◽  
Aline Alves Santana ◽  
Aline Boveto Santamarina ◽  
Lila Missae Oyama ◽  
Érico Chagas Caperuto ◽  
...  

The aim of this study was to evaluate the effects of exercise training (ET, 50–70% of VO2 max, 5 days/week) and detraining (DT) on inflammatory and metabolic profile after myocardial infarction (MI) in rats. Male Wistar rats were divided into control (C,n=8), sedentary infarcted (SI,n=9), trained infarcted (TI, n=10; 3 months of ET), and detrained infarcted (DI,n=11; 2 months of ET + 1 month of DT). After ET and DT protocols, ventricular function and inflammation, cardiovascular autonomic modulation (spectral analysis), and adipose tissue inflammation and lipolytic pathway were evaluated. ET after MI improved cardiac and vascular autonomic modulation, and these benefits were correlated with reduced inflammatory cytokines on the heart and adipose tissue. These positive changes were sustained even after 1 month of detraining. No expressive changes were observed in oxidative stress and lipolytic pathway in experimental groups. In conclusion, our results strongly suggest that the autonomic improvement promoted by ET, and maintained even after the detraining period, was associated with reduced inflammatory profile in the left ventricle and adipose tissue of rats subjected to MI. These data encourage enhancing cardiovascular autonomic function as a therapeutic strategy for the treatment of inflammatory process triggered by MI.


2020 ◽  
Author(s):  
RQ Ramos ◽  
RR Moraes ◽  
GC Lopes

Clinical Relevance The use of multipeak LED light-curing guarantees efficiency on light activation of Ivocerin-containing light-cured resin cement.


2018 ◽  
Vol 69 (3) ◽  
pp. 739-743 ◽  
Author(s):  
Madalina Irina Mitran ◽  
Ilinca Nicolae ◽  
Corina Daniela Ene ◽  
Cristina Iulia Mitran ◽  
Clara Matei ◽  
...  

Chemicals used in the manufacture of synthetic fibers have been associated with undesirable side effects such as itching or skin lesions and it seems that they are involved in the induction of pathological processes such as oxidative stress and inflammation. Lichen planus (LP) can be regarded as an inflammatory disorder, chemical and physical factors playing an important role in the perpetuation of the inflammatory process. Gamma-glutamyl transpeptidase (GGT) plays an important role in the preservation of skin architecture and modulation of skin inflammation. In this study, we found that GGT activity is increased in LP patients with mild inflammation, whilst GGT is inactivated under conditions of severe inflammation. Therefore, GGT is involved in the inflammatory process, but there is no a positive correlation between its activity and the intensity of the inflammatory response. This functional adaptation of the enzyme may be due to down-regulation of its synthesis under free radical overload conditions. Understanding the molecular mechanisms involved in the modulation of intracellular redox homeostasis is an important step in the pharmacological management of patients with LP.


Author(s):  
Olugbemi T. Olaniyan ◽  
Olakunle A. Ojewale ◽  
Ayobami Dare ◽  
Olufemi Adebayo ◽  
Joseph E. Enyojo ◽  
...  

Abstract Objectives Lead primarily affects male reproductive functions via hormonal imbalance and morphological damage to the testicular tissue with significant alteration in sperm profile and oxidative markers. Though, different studies have reported that Cocos nucifera L. oil has a wide range of biological effects, this study aimed at investigating the effect of Cocos nucifera L. oil on lead acetate-induced reproductive toxicity in male Wistar rats. Methods Twenty (20) sexually matured male Wistar rats (55–65 days) were randomly distributed into four groups (n=5). Group I (negative control)—distilled water orally for 56 days, Group II (positive control)—5 mg/kg bwt lead acetate intraperitoneally (i.p.) for 14 days, Group III—6.7 mL/kg bwt Cocos nucifera L. oil orally for 56 days and Group IV—lead acetate intraperitoneally (i.p.) for 14 days and Cocos nucifera L. oil for orally for 56 days. Rats were sacrificed by diethyl ether, after which the serum, testis and epididymis were collected and used for semen analysis, biochemical and histological analysis. Results The lead acetate significantly increases (p<0.05) testicular and epididymal malondialdehyde (MDA) levels, while a significant reduction (p<0.05) in sperm parameters, organ weight, testosterone and luteinizing hormone was observed when compared with the negative control. The coadministration of Cocos nucifera oil with lead acetate significantly increases (p<0.05) testosterone, luteinizing hormone, sperm parameters and organ weight, with a significant decrease (p<0.05) in MDA levels compared with positive control. Histological analysis showed that lead acetate distorts testicular cytoarchitecture and germ cell integrity while this was normalized in the cotreated group. Conclusions Cocos nucifera oil attenuates the deleterious effects of lead acetate in male Wistar rats, which could be attributed to its polyphenol content and antioxidant properties.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 470
Author(s):  
Andrea Kowalska ◽  
Jerzy Sokolowski ◽  
Kinga Bociong

The presented paper concerns current knowledge of commercial and alternative photoinitiator systems used in dentistry. It discusses alternative and commercial photoinitiators and focuses on mechanisms of polymerization process, in vitro measurement methods and factors influencing the degree of conversion and hardness of dental resins. PubMed, Academia.edu, Google Scholar, Elsevier, ResearchGate and Mendeley, analysis from 1985 to 2020 were searched electronically with appropriate keywords. Over 60 articles were chosen based on relevance to this review. Dental light-cured composites are the most common filling used in dentistry, but every photoinitiator system requires proper light-curing system with suitable spectrum of light. Alternation of photoinitiator might cause changing the values of biomechanical properties such as: degree of conversion, hardness, biocompatibility. This review contains comparison of biomechanical properties of dental composites including different photosensitizers among other: camphorquinone, phenanthrenequinone, benzophenone and 1-phenyl-1,2 propanedione, trimethylbenzoyl-diphenylphosphine oxide, benzoyl peroxide. The major aim of this article was to point out alternative photoinitiators which would compensate the disadvantages of camphorquinone such as: yellow staining or poor biocompatibility and also would have mechanical properties as satisfactory as camphorquinone. Research showed there is not an adequate photoinitiator which can be as sufficient as camphorquinone (CQ), but alternative photosensitizers like: benzoyl germanium or novel acylphosphine oxide photoinitiators used synergistically with CQ are able to improve aesthetic properties and degree of conversion of dental resin.


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