scholarly journals Comparative evaluation of volumetric changes of three different retrograde calcium silicate materials placed under different pH condititions

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
So Yeon Kwon ◽  
Min-Seock Seo
Keyword(s):  
Calcium Silicate ◽  
Room Temperature ◽  
Volume Ratio ◽  
Acidic Environment ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Saline Environment ◽  
Significant Difference ◽  
Calcium Silicate Cements ◽  
Materials Used

Abstract Background The present study aimed to compare the volumetric changes of three calcium silicate cements after retrofilling and placing under different pH conditions via micro-computed tomography (micro-CT) scan. Methods Forty-two extracted human single-rooted teeth were randomly assigned to three groups according to the retrofilling materials used (Biodentine, Endocem MTA, and ProRoot MTA). Each group was divided into two subgroups according to the setting condition. The teeth in one group were immersed in normal saline for 5 days at room temperature, and the teeth in the other group were immersed in butyric acid (pH = 5.4) for 5 days at room temperature. The volume ratios of the retrofilling material were calculated via micro-CT imaging. Results The volume ratios of the Biodentine and Endocem MTA groups were significantly different between the two setting environment, and these groups had significantly lower filled volume ratio (Vf, %) in the acidic environment than in the saline environment (pH = 5.4). Meanwhile, the volume ratio of the ProRoot MTA group did not significantly differ between the two setting environments. All materials under the acidic setting condition had relative radiolucency in the area in contact with the acidic solution. Conclusion The Vf ratio of the Biodentine and Endocem MTA cements was significantly lower in the acidic environment than in the saline environment. No statistically significant difference was observed in the Vf ratio of ProRoot MTA between the two setting environments.

scholarly journals Comparison of Volume Changes in Different Environmental Conditions After Retrofilling Using Three Calcium Silicate Cements

2020 ◽  
Author(s):  
so yeon kwon ◽  
minseock seo
Keyword(s):  
Calcium Silicate ◽  
Room Temperature ◽  
Volume Ratio ◽  
Acidic Environment ◽  
Micro Computed Tomography ◽  
Saline Environment ◽  
Sealing Ability ◽  
Significant Difference ◽  
Calcium Silicate Cements ◽  
Materials Used

Abstract Background The present study aimed to compare the marginal sealing ability of three calcium silicate cements after retrofilling at different pH levels via micro-computed tomography (CT) scan.Methods Forty-two extracted human single-rooted teeth were randomly assigned to three groups according to the retrofilling materials used (Biodentine, Endocem MTA, and ProRoot MTA). Each group was divided into two subgroups according to the setting condition. The teeth in one group were immersed in normal saline for 5 days at room temperature, and the teeth in the other group were immersed in butyric acid (pH = 5.4) for 5 days at room temperature. To investigate marginal sealing ability, the volume ratios of the retrofilling material were calculated via micro-CT imaging.Results The volume ratios of the Biodentine and Endocem MTA groups were significantly different between the two setting environment, and these groups had significantly lower filled volume ratio (Vf, %) in the acidic environment than in the saline environment (pH = 5.4). Meanwhile, the volume ratio of the ProRoot MTA group did not significantly differ between the two setting environments. All materials under the acidic setting condition had relative radiolucency in the area in contact with the acidic solution.Conclusions The Vf ratio of the Biodentine and Endocem MTA cements was significantly lower in the acidic environment than in the saline environment. Meanwhile, no statistically significant difference was observed in the Vf ratio of ProRoot MTA between the two setting environments.

scholarly journals Comparison of Obturation Quality between Calcium Silicate-Based Sealers and Resin-Based Sealers for Endodontic Re-treatment

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 72
Author(s):  
Hye-Ryeon Jin ◽  
Young-Eun Jang ◽  
Yemi Kim
Keyword(s):  
Calcium Silicate ◽  
Continuous Wave ◽  
Calculated Data ◽  
Endodontic Treatment ◽  
Void Volume ◽  
Lower Percentage ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Significant Difference ◽  
Ah Plus

Background: The objective of this micro-computed tomography (micro-CT)-based study was to compare the filling quality of endodontic treatment and endodontic Re-treatment between two sealers with matched obturation techniques: calcium silicate-based sealer (Endoseal TCS) with a single-cone technique (SCT) and resin-based sealer (AH Plus) with a continuous wave technique (CWT). Methods: Forty maxillary premolars were selected and assigned into four groups, according to the obturation methods of the first endodontic treatment and Re-treatment (n = 10). The AP/AP group was first treated with AH Plus/CWT, then re-treated with AH Plus/CWT. The AP/ET group was first treated with AH Plus/CWT, then re-treated with Endoseal TCS/SCT. The ET/AP group was first treated with Endoseal TCS/SCT, then re-treated with AH Plus/CWT, and the ET/ET group was first treated with Endoseal TCS/SCT, then re-treated with Endoseal TCS/SCT. The specimens were scanned using micro-CT at three time points: after the first endodontic treatment, after gutta-percha (GP) cone removal, and after Re-treatment. The void volume of root canal obturation and the volume of the remaining filling materials were calculated. Data were analyzed using Student’s t-tests and ANOVA. Results: The Endoseal TCS groups (ET/AP and ET/ET) showed a lower percentage of voids than the AH plus groups (AP/AP and AP/ET) on the whole canal and the apical third, after first obturation (p < 0.05). The AH plus group showed significantly fewer remnants than the Endoseal TCS group after GP removal (p < 0.05). Re-treated canals and initially treated canals had similar void volumes (p > 0.05). There was no significant difference in void volume after Re-treatment, regardless of whether the same or different sealers were used for the first treatment and Re-treatment (p < 0.05). Conclusions: Endoseal TCS sealer and AH Plus sealer had a similar Re-treatment efficacy, regardless of which sealer was used in the previous treatment.

scholarly journals Micro-Computed Tomography Analysis of Subchondral Bone Regeneration Using Osteochondral Scaffolds in an Ovine Condyle Model

2021 ◽  
Vol 11 (3) ◽  
pp. 891
Author(s):  
Taylor Flaherty ◽  
Maryam Tamaddon ◽  
Chaozong Liu
Keyword(s):  
Computed Tomography ◽  
Bone Regeneration ◽  
Subchondral Bone ◽  
Volume Ratio ◽  
Bone Volume ◽  
Osteochondral Defects ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Trabecular Thickness ◽  
Osteochondral Scaffold

Osteochondral scaffold technology has emerged as a promising therapy for repairing osteochondral defects. Recent research suggests that seeding osteochondral scaffolds with bone marrow concentrate (BMC) may enhance tissue regeneration. To examine this hypothesis, this study examined subchondral bone regeneration in scaffolds with and without BMC. Ovine stifle condyle models were used for the in vivo study. Two scaffold systems (8 mm diameter and 10 mm thick) with and without BMC were implanted into the femoral condyle, and the tissues were retrieved after six months. The retrieved femoral condyles (with scaffold in) were examined using micro-computed tomography scans (micro-CT), and the micro-CT data were further analysed by ImageJ with respect to trabecular thickness, bone volume to total volume ratio (BV/TV) ratio, and degree of anisotropy of bone. Statistical analysis compared bone regeneration between scaffold groups and sub-set regions. These results were mostly insignificant (p < 0.05), with the exception of bone volume to total volume ratio when comparing scaffold composition and sub-set region. Additional trends in the data were observed. These results suggest that the scaffold composition and addition of BMC did not significantly affect bone regeneration in osteochondral defects after six months. However, this research provides data which may guide the development of future treatments.

Effect of current density on the porous silicon preparation as gas sensors**

2021 ◽  
Vol 30 (1) ◽  
pp. 257-264
Author(s):  
Muna H. Kareem ◽  
Adi M. Abdul Hussein ◽  
Haitham Talib Hussein
Keyword(s):  
Porous Silicon ◽  
Gas Sensors ◽  
Current Density ◽  
Room Temperature ◽  
Low Cost ◽  
High Surface ◽  
Volume Ratio ◽  
Etching Time ◽  
Force Microscopy ◽  
Materials Used

Abstract In this study, porous silicon (PSi) was used to manufacture gas sensors for acetone and ethanol. Samples of PSi were successfully prepared by photoelectrochemical etching and applied as an acetone and ethanol gas sensor at room temperature at various current densities J= 12, 24 and 30 mA/cm2 with an etching time of 10 min and hydrofluoric acid concentration of 40%. Well-ordered n-type PSi (100) was carefully studied for its chemical composition, surface structure and bond configuration of the surface via X-ray diffraction, atomic force microscopy, Fourier transform infrared spectroscopy and photoluminescence tests. Results showed that the best sensitivity of PSi was to acetone gas than to ethanol under the same conditions at an etching current density of 30 mA/cm2, reaching about 2.413 at a concentration of 500 parts per million. The PSi layers served as low-cost and high-quality acetone gas sensors. Thus, PSi can be used to replace expensive materials used in gas sensors that function at low temperatures, including room temperature. The material has an exceptionally high surface-to-volume ratio (increasing surface area) and demonstrates ease of fabrication and compatibility with manufacturing processes of silicon microelectronics.

scholarly journals Evaluation of bond strength of one step and two steps self-etch adhesive agents with two different pulp-capping materials

2020 ◽  
Vol 67 (2) ◽  
pp. 75-82
Author(s):  
Vasilka Rendzova ◽  
Sonja Apostolska ◽  
Emilija Kostadinovska ◽  
Maja Antanasova ◽  
Marina Eftimoska ◽  
...  
Keyword(s):  
Bond Strength ◽  
Calcium Silicate ◽  
Testing Machine ◽  
Pulp Capping ◽  
Dentin Adhesives ◽  
Significant Difference ◽  
One Step ◽  
Calcium Silicate Cements ◽  
Set Up ◽  
Self Etch

Primary purpose of restorative dentistry is to preserve pulp vitality. Besides calcium hydroxide, the application of calcium silicate cements as a material for direct pulp capping has become used recently. The aim of our study was to investigate the influence of materials for direct and indirect pulp capping on the bond strength of composite restorations using two different self etch dentin adhesives. The test was performed on 60 intact molars extracted for periodontal or orthodontic reasons. The prepared samples were divided into the two groups and three subgroups depending on the adhesive and pulp cupping material. Two different calcium silicate based materials were used for pulp cupping. One step and two steps self etch dentin adhesive was applied to prepared specimens depending on the group and with the help of a specially made metal mold set up a composite post. The share bond strength was assessed using a universal testing machine. The results showed significant difference in the share bond strength between the samples treated with TheraCal LC and Biodentine with TheraCal LC being superior to Biodentine.

scholarly journals Microtomographic Evaluation of Canal Centralization and Dentine Removal after Canal Preparation with Two Rotary Systems: HyFlex EDM and ProTaper Next

2022 ◽  
Author(s):  
Vivian Ronquete ◽  
Alexandre Sigrist de Martin ◽  
Karin Zuim ◽  
Thais Machado de Carvalho Coutinho ◽  
Eduardo Fagury Videira Marceliano ◽  
...  
Keyword(s):  
Root Canal ◽  
Root Diameter ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Type Iv ◽  
Canal Diameter ◽  
Mandibular Molar ◽  
Apical Transportation ◽  
Significant Difference ◽  
Before And After

Abstract Objective This study compared the ProTaper Next (PTN; Dentsply Sirona, Tulsa, Oklahoma, United States) and HyFlex EDM (HEDM; Coltene/Whaledent AG, Alstätten, Switzerland) systems using micro–computed tomography (CT). Materials and Methods Twenty-one mesial roots classified as Vertucci's type IV from extracted mandibular first molars with curvatures between 20 and 40 degrees were selected. The teeth were scanned using a micro-CT before and after root canal preparation by both systems, applied to the same root, in alternating canals. The following parameters were analyzed: canal centering, apical transportation, root canal diameter/root diameter. Results No statistically significant differences between both systems were observed for any of the assessed morphological parameters (p > 0.05). All canals presented diameter enlargement of more than 40% in relation to root diameter in the cervical and middle segments. No statistically significant difference was noted between the HEDM and PTN groups. The wear percentage for the HEDM group in the cervical and middle thirds were 49.66 ± 8.65 and 46.48 ± 14.29, respectively, and 51.02 ± 11.81 and 45.48 ± 10.79 for the PTN group, respectively. Conclusion Both systems displayed similar mandibular molar mesial canals preparation, with no differences noted for any of the assessed parameters. Both groups showed increased canal diameter in the cervical and middle thirds by more than 40%.

scholarly journals Correlation between two-dimensional micro-CT and histomorphometry for assessment of the implant osseointegration in rabbit tibia model

2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Hao-Zhen Lyu ◽  
Jae Hyup Lee
Keyword(s):  
Histological Section ◽  
Bone Architecture ◽  
Micro Ct ◽  
Contact Ratio ◽  
Micro Computed Tomography ◽  
Significant Linear Correlation ◽  
Significant Difference ◽  
Rabbit Tibia ◽  
Bone To Implant Contact ◽  
Aluminum Filter

Abstract Background Histology is considered as a gold standard for analyzing bone architecture. However, histomorphometry is a destructive method and only offers the bone information of a limited location. Micro-computed tomography (μCT) is a non-destructive technology and provides a slice at any site. The aim of this study was to compare the correlation of the Bone-to-Implant Contact ratio (BIC) between 2D micro-CT (μCT) and histomorphometry and to investigate a method for assessing the osseointegration of the implant by 2D μCT. Methods A total of 18 implants were divided into three groups (6 implants per group), and inserted into the rabbit tibia defects as follow: implant only (Implant group), implant with β-TCP/hydrogel (TCP group), implant with rhBMP-2 loaded β-TCP/hydrogel composite (BMP-2 group). After 4 weeks of implantation, the specimens were collected to take the micro-CT scan with an aluminum filter and performed H&E staining on the undecalcified sections. The 2D μCT slices were chosen at an angle of 0°, 45°, 90° and 135° with the representative histological section to measure BIC. And the correlations between BICs of 2D μCT and BICs of histology were evaluated. Results In each group, BICs at the same sites measured by histomorphometry and corresponding 2D μCT presented the same trend and shown no significant difference between the two methods (P > 0.05). BICs of histological sections and BICs of corresponding 2D μCT slices presented a strong correlation in the implant group (γ = 0.74, P = 0.09), a moderate correlation in the TCP group (γ = 0.46, P = 0.35), a weak correlation in the BMP-2 group (γ = 0.30, P = 0.56). In the implant group, the relationship between BIC-Mean-μCTs and BICs-Histology has presented a significant linear correlation (γ = 0.84, P = 0.04). Conclusions Integrating bone information of several 2D μCT slices in different sites to measure BIC is a feasible method for assessing the implant osseointegration.

scholarly journals Compressive strength of calcium silicate-based cement

2018 ◽  
Vol 65 (1) ◽  
pp. 7-13
Author(s):  
Vanja Opačić Galić ◽  
Zoran Stamenić ◽  
Violeta Petrović ◽  
Vukoman Jokanović ◽  
Slavoljub Živković
Keyword(s):  
Compressive Strength ◽  
Calcium Silicate ◽  
Calcium Silicate Cement ◽  
Crosshead Speed ◽  
Universal Testing ◽  
Significant Difference ◽  
Calcium Silicate Cements ◽  
Post Hoc ◽  
One Way Anova ◽  
Over Time

Summary Introduction The aim of this study was to compare compressive strength (Cs) of new nanostructural calcium silicate based cement (nCS) with commercial calcium silicate cement and conventional GIC. Methods Four nanostructural materials were tested: nanostructural calcium silicate based cement (nCS) (Jokanović et al.), MTA Plus (Cerkamed, Poland), Fuji IX (GC Corporation, Japan) and Ketac Universal Aplicap (3M ESPE, USA). Five samples of each material were mixed in accordance with manifecturer’s guidelines and positioned in metal moulds (ϕ4mm and 6mm). Compressive strength (Cs) expressed in MPa was determined after 24 hours, 7 days and 28 days respectively. Measurements were performed on universal testing equipment (Tinius Olsen, USA) at a crosshead speed of 1mm/min. For processing the results one-way ANOVA and post-hoc test were used. Results The highest values of compressive strength after 24h was found in conventional GIC Fuji IX (mean 38.56±13.31) and Ketac Universal (mean 40.77±7.96). Calcium silicate cements after 24h showed low values of compressive strength (MTA Plus 5.91±0.28 MPa, nCS 1.35±0.36 MPa). After 7 days, FUJI IX 47.42±9.33 MPa and Ketac Universal 35.25±10.60 MPa showed higher value of compressive strength than MTA Plus (15.09±2.77 MPa) and nCS (11.06±0.88 MPa). After 28 days the Cs value for conventional GIC Fuji IX was 48.03±7.82 MPa and Ketac Universal 36.65±11.13 MPa while for calcium silicate cements it was 16.47±1.89 MPa and nCS 14.39±1.63 MPa. There was statistically significant difference (p<0.05) in Cs between conventional GIC and CS cements after 24h, 7 and 28 days. Conclusions Calcium silicate cements initially showed lower values of compressive strength than conventional GIC that increased over time.

Experimental Analysis for the Anisotropic Flows in Cancellous Bone

2017 ◽  
Author(s):  
Makoto Ito ◽  
Simon Tupin ◽  
Hitomi Anzai ◽  
Anna Suzuki ◽  
Makoto Ohta
Keyword(s):  
Bone Marrow ◽  
Cancellous Bone ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Anisotropic Permeability ◽  
Hematopoietic Stem ◽  
Average Porosity ◽  
Significant Difference ◽  
Flow Directions ◽  
Two Parameters

Cancellous bone contains bone marrow where hematopoietic stem cells (HSCs) are produced. Those cells represent an interest in the treatment of leukemia during which transplantation of bone marrow is performed to replace patient degraded cells. HSCs are usually harvested by a puncture in the cancellous bone of the donor’s ilium using a needle. However, this procedure can cause severe burden to the donor because of its high invasiveness. The flow of bone marrow is strongly related to the harvesting of HSCs and permeability is one of the major parameters to characterize cancellous bone. Previous researches have already shown an anisotropy of permeability in femur, whereas punctures are usually performed in the iliac cancellous bone. The objective of this paper is to characterize the anisotropic permeability of iliac cancellous bone. Digital images of a porcine iliac cancellous bone sample were obtained by micro-computed tomography (micro-CT), and three locations were selected to fabricate bone models, reproduced by 3D printing at three times magnification. To compare the structure of manufactured models, porosity and its variations along X, Y and Z direction were evaluated from micro-CT images. To measure permeability, a specific perfusion system was developed. The pressure drop between the upstream and the downstream of bone models were measured at different flow rates, reaching a Reynolds number of 27–158, appropriate for the aspiration condition. Darcy-Forchheimer’s law was then applied to calculate the permeability and Forchheimer coefficient of bone models. Results revealed different porosities and resultant permeabilities for each bone nodels. A positive correlation links those two parameters. Different fluctuations of porosity were evaluated along each direction although no significant difference of average porosity was observed. On the other hand, different permeabilities and Forchheimer coefficients were measured in each direction with various degrees of anisotropy. Permeabilities in three orthogonal directions of the model ranged from 1.96 × 10−10 to 4.29 × 10−10 m2. Results indicate that transport properties in cancellous bone depend on the flow directions. The anisotropy of permeability can be used for evaluation of flow in cancellous bone.

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