scholarly journals Exposure of Biomimetic Composite Materials to Acidic Challenges: Influence on Flexural Resistance and Elastic Modulus

Biomimetics ◽  
2020 ◽  
Vol 5 (4) ◽  
pp. 56
Author(s):  
Andrea Scribante ◽  
Simone Gallo ◽  
Stefano Scarantino ◽  
Alberto Dagna ◽  
Claudio Poggio ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Composite Materials ◽  
Flexural Strength ◽  
Testing Machine ◽  
Distilled Water ◽  
Group 4 ◽  
Significant Difference ◽  
Group 5 ◽  
Group 2 ◽  
Flexural Resistance

Acidic conditions of the oral cavity, including soft drinks and cariogenic bacteria, represent a damage for restorative biomimetic composite materials. The aim of this study is to assess the influence of two different acidic challenges on the flexural strength and elastic modulus of five composites: x-tra fil (Group 1, XTF), GrandioSO x-tra (Group 2, GXT), Admira Fusion x-tra (Group 3, AFX), VisCalor bulk (Group 4, VCB), and Enamel Plus HRi (Group 5, EPH). Thirty samples for each group were randomly divided and assigned to three different treatments: storage in distilled water as the controls (subgroups 1a–5a), 3 weeks distilled water + 1 week Coca-Cola (subgroups 1b-5b), and 4 weeks Coca-Cola (subgroups 1c–5c). For each subgroup, the flexural strength and elastic modulus were measured using an Instron universal testing machine, and data were submitted to statistical analysis. Considering subgroups B, no material showed a significant difference in the flexural strength with the controls (p > 0.05), whereas for subgroups C, only GXT and VCB showed significantly lower values (p < 0.05). AFX reported the lowest flexural strength among the materials tested. As regards the elastic modulus, no material showed a significant variation after acidic storages when compared with the respective control (p > 0.05). AFX and EPH reported the lowest elastic modulus compared to the other materials. All composites tested showed adequate flexural properties according to the standards, except for AFX. This biomimetic material, along with EPH, might be indicated for V class (cervical) restorations considering the lowest values of elasticity reported.

scholarly journals Effect of fluoride-containing solutions on the surface of cast commercially pure titanium

2009 ◽  
Vol 20 (3) ◽  
pp. 201-204 ◽  
Author(s):  
Marcelo Bighetti Toniollo ◽  
Rodrigo Tiossi ◽  
Ana Paula Macedo ◽  
Renata Cristina Silveira Rodrigues ◽  
Ricardo Faria Ribeiro ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Pure Titanium ◽  
Distilled Water ◽  
Commercially Pure Titanium ◽  
Group 4 ◽  
Commercially Pure ◽  
Significant Difference ◽  
Group 5 ◽  
Group 2 ◽  
Cp Ti

This study evaluated the effects of fluoride-containing solutions on the surface of commercially pure titanium (CP Ti) obtained by casting. CP Ti specimens were fabricated and randomly assigned to 5 groups (n=10): group 1: stored in distilled water at 37 ± 1ºC; group 2: stored in distilled water at 37 ± 1ºC and daily immersed in 0.05% NaF for 3 min; group 3: stored in distilled water at 37 ± 1ºC and daily immersed in 0.2% NaF for 3 min; group 4: stored in distilled water at 37 ± 1ºC; and immersed in 0.05% NaF every 15 days for 3 min; and group 5: stored in distilled water at 37 ± 1ºC and immersed in 0.2% NaF every 15 days for 3 min. Surface roughness was measured with a profilometer immediately after metallographic polishing of the specimens (T0) and at 15-day intervals until completing 60 days of experiment (T15, T30, T45, T60). Data were analyzed statistically by ANOVA and Tukey's test (α=0.05). There was no statistically significant difference (p>0.05) in surface roughness among the solutions. In conclusion, fluoride-containing solutions (pH 7.0) used as mouthwashes do not damage the surface of cast CP Ti and can be used by patients with titanium-based restorations.

scholarly journals Biaxial flexural strength of different types of monolithic zirconia

2019 ◽  
Vol 22 (1) ◽  
pp. Process
Author(s):  
Shereen Ahmed Nossair ◽  
Tarek Salah ◽  
Kamal Khaled Ebeid
Keyword(s):  
Flexural Strength ◽  
Zirconia Ceramic ◽  
Group 4 ◽  
Dental Esthetics ◽  
Biaxial Flexural Strength ◽  
Different Types ◽  
Monolithic Zirconia ◽  
Group 5 ◽  
Group 2 ◽  
Post Hoc

Objective: This study was designed to evaluate the biaxial flexural strength (BFS) of different types of unshaded and shaded monolithic zirconia. Material and Methods: 120 monolithic zirconia ceramic discs were fabricated. They were divided into twelve groups (n=10), Group 1; Bruxzir unshaded, Group 2; Bruxzir shaded A2, Group 3; Bruxzir anterior white, Group 4; Bruxzir anterior shade A2, Group 5; Prettau unshaded, Group 6; Prettau shaded with A2 coloring liquid, Group 7; Prettau anterior white, Group 8; Prettau anterior shaded with A2 coloring liquid, Group 9; Katana HT white, Group 10; Katana HT shade A2, Group 11; Katana ST white, Group 12; Katana ST shade A2. All discs were milled using a dental milling machine, and had final dimensions after sintering of 15 mm diameter and 1 mm thickness. BFS was tested using piston on three ball technique. Results:  One-way ANOVA revealed significant differences among the 12 groups. Tukey post-hoc tests revealed no significant differences between the groups 3, 4, ,7 ,8 11, and 12. However, they all had BFS values that are significantly lower than all other groups. Group 2 showed statistically significant higher BFS values when compared to group 3,4, 7, 8, 11, and 12 while it showed statistically significant lower values when compared to groups 1, 5, 6, 9, and 10. Conclusion: Increase in the yttria content in zirconia led to a decrease in its BFS. Shading of zirconia did not have a significant effect on the final strength of zirconia. KeywordsDental ceramics; Dental esthetics; Flexural strength; Shaded zirconia. 

In vivosilymarin’s antioxidant and anti-apoptotic effects on photodynamic therapy’s responsiveness

2017 ◽  
Vol 21 (03) ◽  
pp. 189-197 ◽  
Author(s):  
Vlad Dionisie ◽  
Simona Clichici ◽  
Rodica M. Ion ◽  
Oana O. Danila ◽  
Remus Moldovan ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Reactive Oxygen Species Generation ◽  
Group 4 ◽  
Significant Difference ◽  
Anti Oxidant ◽  
Group 3 ◽  
Group 5 ◽  
Group 2 ◽  
Apoptotic Effects ◽  
Oxidant Effect

Several studies have shown that some anti-oxidant natural compounds in combination with photodynamic therapy (PDT) can enhance the effectiveness of treatment. The aim of this study is to evaluate the effect of silymarin (SIL) in combination with 5,10,15,20-tetra-sulphonato-phenyl-porphyrin (TSPP) based photodynamic therapy, on experimental tumors. 30 Wistar rats with Walker carcinosarcoma, were divided into 6 groups: group 0 (control) — control, untreated group; group 1 (TSPP) — one dose of TSPP; group 2 (SIL) — silymarin; group 3 (PDT) — TSPP and irradiation 24 h after; group 4 (SIL[Formula: see text]PDT) — silymarin, TSPP and irradiation 24 h after; group 5 (SIL[Formula: see text]IR) and group 6 (IR) — irradiation and in addition, group 5 received SIL. Silymarin administered before photodynamic therapy decreased the lipid peroxidation ([Formula: see text] < 0.05) and modulated the antioxidant defense in tumor treated with PDT and silymarin suggesting that silymarin administration along with photodynamic therapy has an anti-oxidant effect. The caspase — 8 level and -3 activity increased in PDT and PDT [Formula: see text] SIL groups compared to the control; between the two groups there was a significant difference in term of apoptosis in favor to PDT. In conclusion, silymarin administration inhibited the reactive oxygen species generation and reduced the tumoral cells’ apoptosis, suggesting that natural compound administered before photodynamic therapy did not improve the therapy’s effect.

Bond Integrity of Titanium Surface to Resin Cement After Conditioning with Different Photobiomodulataion Therapy (PBT)

2021 ◽  
Vol 11 (5) ◽  
pp. 970-975
Author(s):  
Khold Al Ahdal ◽  
Laila Al Deeb ◽  
Mohammed S. Bin-Shuwaish ◽  
Rana S. Al-Hamdan ◽  
Modhi Al Deeb ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Testing Machine ◽  
Resin Cement ◽  
Control Group ◽  
Sem Images ◽  
Group 4 ◽  
Modes Of Failure ◽  
Group 5 ◽  
Group 2 ◽  
Group 1

The aim of the present study was to evaluate the efficacy of interfacial bonding between resin cement and titanium alloy conditioned with different Photobiomodulataion Therapy (PBT) in comparison with conventional regimes. Seventy-five samples of titanium bar were segmented polished; and based on conditioning regime divided into five groups (15 each specimens). Group 1: No treatment (control), Group 2: Sand blasting with 120 µm Al2O3, Group 3: Er,Cr:YSGG (ECL), Group 4: Er:YAG laser (EYL), Group 5: Nd:YAG laser (NYL). After different conditioning regimes, resin cement was mixed and applied. All specimens were thermocycled for 500 cycles and positioned on universal testing machine for shear bond strength testing. Modes of failure was assessed by a single examiner using stereomicroscope at 40× magnification. Three pairs of specimens in each group were sputter coated and scanning electron microscope (SEM) images were taken at 1000× magnification using 20 Kv. The highest SBS values were observed in group 2 (14.25±2.29 MPa) and the lowest bond values were displayed in group 1 (6.98 ±0.59 MPa). Titanium alloy abutments conditioned with different laser prototypes ECL (11.22±1.40 MPa), EYL (9.29±1.22 MPa) and NYL (9.12 ±1.84 MPa) exhibited comparable SBS (p > 0.05). Adhesive failures were primarily dominant among all experimental groups. Photo-biomodulation in the form of ECL lasers has the potential to be used as a supplement to sandblasting procedure in conditioning of cement retained titanium alloy implant abutments.

scholarly journals Flexural Properties and Elastic Modulus of Different Esthetic Restorative Materials: Evaluation after Exposure to Acidic Drink

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Andrea Scribante ◽  
Marco Bollardi ◽  
Marco Chiesa ◽  
Claudio Poggio ◽  
Marco Colombo
Keyword(s):  
Elastic Modulus ◽  
Flexural Strength ◽  
Water Immersion ◽  
Testing Machine ◽  
Distilled Water ◽  
Resin Composites ◽  
Restorative Material ◽  
Universal Testing ◽  
Restorative Materials ◽  
Acidic Beverages

Background. Acidic beverages, such as soft drinks, can produce erosion of resin composites. The purpose of the present study was to investigate mechanical properties of different esthetic restorative materials after exposure to acidic drink. Methods. Nine different composites were tested: nanofilled (Filtek Supreme XTE, 3M ESPE), microfilled hybrid (G-ænial, GC Corporation), nanohybrid Ormocer (Admira Fusion, Voco), microfilled (Gradia Direct, GC Corporation), microfilled hybrid (Essentia, GC Corporation), nanoceramic (Ceram.X Universal, Dentsply De Trey), supranano spherical hybrid (Estelite Asteria, Tokuyama Dental Corporation), flowable microfilled hybrid (Gradia Direct Flo, GC Corporation), and bulk fill flowable (SureFil SDR flow, Dentsply De Trey). Thirty specimens of each esthetic restorative material were divided into 3 subgroups (n=10): specimens of subgroup 1 were used as control, specimens of subgroup 2 were immersed in 50 ml of Coca Cola for 1 week, and specimens of subgroup 3 were immersed in 50 ml of Coca Cola for 1 month. Flexural strength and elastic modulus were measured for each material with an Instron Universal Testing Machine. Data were submitted to statistical analysis. Results. After distilled water immersion, nanofilled composite showed the highest value of both flexural strength and elastic modulus, but its flexural values decreased after acidic drink immersion. No significant differences were reported between distilled water and acidic drink immersion for all other materials tested both for flexural and for elastic modulus values. Conclusions. Even if nanofilled composite showed highest results, acidic drink immersion significantly reduced flexural values.

Dentin Bond Strength of Composites with Self-etching Adhesives Using LED Curing Lights

2007 ◽  
Vol 8 (5) ◽  
pp. 34-42 ◽  
Author(s):  
Yonca Korkmaz ◽  
Nuray Attar
Keyword(s):  
Bond Strength ◽  
Testing Machine ◽  
Significance Level ◽  
Group 4 ◽  
Group 6 ◽  
Group 3 ◽  
Curing Light ◽  
Group 5 ◽  
Group 2 ◽  
Self Etch

Abstract Aim The purpose of this study was to investigate the effect of light-emitting diode (LED) light curing units (LCUs) compared with halogen LCUs on the shear bond strength (SBS) of one nanofill composite (Filtek Supreme) and one microhibrid composite (Artemis) with self-etch adhesives. Methods and Materials The buccal surfaces of 60 non-carious extracted human molars were flattened to expose dentin and, subsequently, polished for 60 seconds with 600-grit wet silicon carbide abrasive paper. Specimens were assigned into six groups (n=10) according to composite material, self-etch adhesive, and curing light used as follows: Group 1: Adper Prompt L-Pop (AP) and Filtek Supreme (FS) using an Elipar Free Light (EFL); Group 2: AP and FS using an Elipar Free Light 2 (EFL2); Group 3: AP and FS using a Hilux Expert (HE) light, Group 4: AdheSE (AS)+Artemis (AR) using an EFL; Group 5: AS+AR using an EFL2; and Group 6: AS+AR using a HE light. The specimens were thermocycled for 500 cycles (5°C–55°C) and then loaded to failure in a Zwick universal testing machine at a crosshead speed of 5 mm/minute. SBS values were calculated as megapascals (MPa) and statistically analyzed using the one-way analysis of variance (ANOVA) test at a significance level of 0.05. Results Mean SBS (± standard deviations) values were as follows: Group1: 15.99±5.18; Group 2: 18.76±6.71; Group 3: 17.70±5.04; Group 4: 16.93±3.99; Group 5: 18.01±5.19, and Group 6: 17.46±5.40. There were no statistically significant differences for SBS to dentin among the groups tested. Conclusion The LED curing lights used in the study seem to be comparable with the halogen curing light for nanofill and microhybrid composites used in conjunction with self-etching systems in dentin. The EFL2 reduces curing time, which can be considered as an advantage. Citation Korkmaz Y, Attar N. Dentin Bond Strength of Composites with Self-etching Adhesives Using LED Curing Lights. J Contemp Dent Pract 2007 July;(8)5:034-042.

scholarly journals Evaluation of Apical Filling after Warm Vertical Compaction using Two Different Endodontic Materials: Resilon® and Gutta-Percha

2012 ◽  
Vol 3 (2) ◽  
pp. 166-170
Author(s):  
Carla Zogheib ◽  
Etienne Medioni
Keyword(s):  
Group 4 ◽  
Gutta Percha ◽  
Anterior Teeth ◽  
Significant Difference ◽  
Ah Plus ◽  
Group 3 ◽  
Group 5 ◽  
Group 2 ◽  
Warm Vertical Compaction ◽  
Group 1

ABSTRACT Forty-eight extracted maxillary anterior teeth instrumented with ProTaper system to apical preparations 0.25, 0.40 and 0.60 mm (n = 16 each) were divided into six groups for filling as following: Group 1: Apical preparation 25/100 + gutta-percha/AH Plus sealer, group 2: Apical preparation 25/100 + Resilon/Real Seal, group 3: Apical preparation 40/100 + gutta-percha/AH plus sealer, group 4: Apical preparation 40/100 + Resilon/Real Seal, group 5: Apical preparation 60/100 + gutta-percha/AH plus, group 6: Apical preparation 60/100 + Resilon/Real Seal. All teeth were filled using the warm vertical technique. Horizontal sections at 1, 2 and 3 mm from the apex were observed by SEM under 200 × magnification. Sections were digitally photographed under a stereomicroscope and the images were transferred to a compatible PC for image analysis. The surface area of voids were calculated and compared at all levels; using the Kruskal-Wallis test with Sidak correction and Mann-Whitney U test (p > 0.05). Comparisons within each group (gutta-percha/AH plus and Resilon/Real Seal) showed the presence of voids but there was no significant difference between any level of sectioning for apical preparations of 25 and 40 (p > 0.05). The only difference was in the groups prepared to size 60 and filled with Resilon/ Real Seal which showed significantly more voids than the group filled with gutta-percha/AH plus and especially at the 3 mm level. Conclusion The system Resilon/Real Seal did not achieve better results in terms of sealing ability in the apical third when compared to the conventional gutta-percha/AH plus sealing system. How to cite this article Zogheib C, Naaman A, Medioni E. Evaluation of Apical Filling after Warm Vertical Compaction using Two Different Endodontic Materials: Resilon® and Gutta-Percha. World J Dent 2012;3(2):166-170.

Blood Ca2+ modulates responsiveness of renal 25(OH)D3-1 alpha-hydroxylase to PTH in rats

1987 ◽  
Vol 253 (5) ◽  
pp. E503-E507 ◽  
Author(s):  
T. Matsumoto ◽  
K. Ikeda ◽  
K. Morita ◽  
S. Fukumoto ◽  
H. Takahashi ◽  
...  
Keyword(s):  
Base Line ◽  
Hydroxylase Activity ◽  
Dihydroxyvitamin D ◽  
Group 4 ◽  
Significant Difference ◽  
Group 3 ◽  
Group 5 ◽  
Group 2 ◽  
Serum Inorganic Phosphate ◽  
Group 1

To clarify whether extracellular Ca2+ modulates renal 25-hydroxyvitamin D3 [25(OH)D3]-1 alpha-hydroxylase, thyroparathyroidectomized rats were infused with 15 mM CaCl2, 20 mM EGTA, and/or 2.5 U/h parathyroid hormone (PTH), and blood Ca2+, serum 1,25-dihydroxyvitamin D [1,25(OH)2D], and renal 1 alpha-hydroxylase activity were determined. Rats with CaCl2, EGTA, or PTH infusion (group 1) exhibited low blood Ca2+, serum 1,25(OH)2D, and 1 alpha-hydroxylase activities. Infusion of CaCl2 alone (group 2) caused a significant increase in blood Ca2+ and a reduction in serum 1,25(OH)2D and 1 alpha-hydroxylase compared with group 1. Administration of PTH alone (group 3) markedly elevated blood Ca2+, serum 1,25(OH)2D, and 1 alpha-hydroxylase activity. When EGTA was infused along with PTH (group 4), blood Ca2+ was significantly reduced compared with group 3, and serum 1,25(OH)2D and renal 1 alpha-hydroxylase were further elevated. In contrast, when CaCl2 was infused with PTH (group 5), blood Ca2+ was higher than that in group 3, and serum 1,25(OH)2D and 1 alpha-hydroxylase activities were significantly reduced compared with group 3. No significant difference in serum inorganic phosphate or urinary cAMP excretion was observed by CaCl2 or EGTA infusion in both PTH-treated and nontreated rats. These results demonstrate that extracellular Ca2+ modulates the responsiveness of renal 1 alpha-hydroxylase to PTH as well as the base-line activity of the enzyme in the absence of PTH. These effects of extracellular Ca2+ on renal 1 alpha-hydroxylase may serve to offer an efficient way of regulating 1,25(OH)2D production and serum 1,25(OH)2D concentration by altering the responsiveness of 1 alpha-hydroxylase to PTH and possibly other stimulations depending on the demand for Ca2+.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Feeding preferences of experienced and naïve goats and sheep for the toxic plant Ipomoea carnea subsp. fistulosa

2015 ◽  
Vol 45 (9) ◽  
pp. 1634-1640 ◽  
Author(s):  
Carlos Alberto Oliveira Júnior ◽  
Gabriela Riet-Correa ◽  
Everton Lima ◽  
Danilo Maia Leite ◽  
James A. Pfister ◽  
...  
Keyword(s):  
Cynodon Dactylon ◽  
Feeding Preferences ◽  
Ipomoea Carnea ◽  
Group 4 ◽  
Plant Group ◽  
Significant Difference ◽  
Group 3 ◽  
Group 5 ◽  
Group 2 ◽  
Toxic Plant

<p><bold>Ipomoea carnea</bold> is a toxic plant that grazing goats and cattle may learn to ingest with repeated exposure. The objective of this study was to evaluate the feeding preferences of experienced and non-experienced (naïve) goats and sheep for<bold> I. carnea.</bold>The study used 3 groups of 5 goats (Group 1, experienced that were previously poisoned by the plant; group 2, naïve; Group 3, experienced eaters, composed of animals adapted to eat the fresh plant) and 2 groups of sheep (group 4, experienced that were previously poisoned by the plant; and group 5, naïve). For the test, the animals were placed daily for 10 minutes and 4 days in a rectangular stall (5x7m) with 4 feeders, each with 200g of a different food (<bold>Ipomoea carnea</bold>, commercial concentrate food, recently harvested green grass (mainly <bold>Brachiaria</bold> spp.), and <bold>Cynodon dactylon</bold>hay. The intake of concentrate food was significantly higher (P<0.05) than the consumption of green grass, hay and <bold>I. carnea</bold>. In a second 4 day trial, in which the commercial concentrate food was replaced by freshly harvested <bold>Amorimia septentrionalis</bold>, the ingestion of green grass (<bold>Brachiaria</bold> spp.) was significantly higher (P<0.05) than the consumption of other foods. In both trials there was no significant difference in food consumption between eaters and naïve animals. The results suggest that experienced or naïve sheep and goats do not prefer <bold>I. carnea</bold> when it is offered with other foods or forages, suggesting that animals will avoid the plant and not become poisoned if other food options are available.</p>

Evaluation of the Effect of Different Ferrule Designs on the Fracture Resistance of Endodontically Treated Maxillary Central Incisors Incorporating Fiber Posts, Composite Cores and Crown Restorations

2007 ◽  
Vol 8 (7) ◽  
pp. 62-69 ◽  
Author(s):  
Emre Ozel ◽  
Idil Dikbas ◽  
Jale Tanalp ◽  
Temel Koksal ◽  
Mustafa Ersoy
Keyword(s):  
Fracture Resistance ◽  
Quartz Fiber ◽  
Group 4 ◽  
Fiber Posts ◽  
Significant Difference ◽  
Group 6 ◽  
Group 3 ◽  
Group 5 ◽  
Group 2 ◽  
Group 1

Abstract Aim The purpose of this study was to evaluate the fracture resistance of endodontically treated maxillary central incisors restored with quartz fiber posts, composite cores, and crowns when different types of ferrule designs were incorporated. Methods and Materials Sixty maxillary incisors were divided into six groups: Group 1 (control): teeth with root canal treatments having a full crown prosthesis; Group 2: teeth with a 2 mm circumferential ferrule; Group 3: teeth with a 2 mm ferrule only in the vestibular region; Group 4: teeth with a 2 mm ferrule only in the palatal region; Group 5: teeth with a 2 mm ferrule in the vestibular and palatal region, having cavities in both proximal areas; and Group 6: teeth with no ferrule. The teeth in the experimental groups were restored with quartz fiber posts-composite cores and full metallic crowns. All experimental teeth were subjected to an increasing compressive force with a crosshead speed of 1 mm/min, until fracture occurred. Results The median fracture values of groups were as follows: Group 1: 574.4 N, Group 2: 472.4 N, Group 3: 474.3 N, Group 4: 480.7 N, Group 5: 463.1 N, and Group 6: 297.9 N. A statistically significant difference was found between Group 1 and Group 6 (p< 0.01). Conclusion It was concluded different ferrule designs did not have any influence on the fracture resistance of teeth with fiber posts. The results of this study indicate fiber posts can safely be used for their reinforcing properties. Furthermore, there is no significant change in the resistance of teeth with fiber posts regardless of which ferrule design is incorporated. The property of these types of posts is an additional advantage in clinical practice. Citation Dikbas I, Tanalp J, Ozel E, Koksal T, Ersoy M. Evaluation of the Effect of Different Ferrule Designs on the Fracture Resistance of Endodontically Treated Maxillary Central Incisors Incorporating Fiber Posts, Composite Cores and Crown Restorations. J Contemp Dent Pract 2007 November; (8)7:062-069.

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