scholarly journals Personalized Dental Medicine: Impact of Intraoral and Extraoral Clinical Variables on the Precision and Efficiency of Intraoral Scanning

2020 ◽  
Vol 10 (3) ◽  
pp. 92
Author(s):  
César Martínez-Rodríguez ◽  
Junco-Plana Patricia ◽  
Ortega-Aranegui Ricardo ◽  
Iglesias-Linares Alejandro
Keyword(s):  
T Test ◽  
Surface Material ◽  
Ambient Light ◽  
Lower Incisor ◽  
Second Molar ◽  
Intraoral Scanning ◽  
Time Scanning ◽  
Interobserver Error ◽  
External Light Source

(1) Objectives: The aim is to measure the influence of different intraoral (crowding and molar inclination) and extraoral (surface material and ambient light) conditions on the efficacy and efficiency of intraoral scanning. (2) Methods: In a controlled in vitro experimental study, the samples were divided into six groups showing two types of intraoral conditions—lower incisor crowding (groups 1–3) and lower molar mesial tipping (groups 4–6). Each modified model was replicated using three types of materials with different light-absorption properties (n = 18 models). Each sample was scanned 30 times at light intensities of 0.0, 1800, or 3600 l×, yielding 3240 scans. Scanning efficiency (digital acquisition; scanning chair-time; and scanning failures) and scanning efficacy (undetected volume) were assessed using virtual superimpositions and Mecano Equate software. The intra- and interobserver error and reliability of the method were calculated and data analyses were performed using the t-test, paired t-test, and one-way analysis of variance (p < 0.05). (3) Results: Digital acquisition was influenced by the degree of crowding and molar inclination (p < 0.05). The scanning surface material affected the efficacy and efficiency, which were lower with a calcium sulfate hemihydrate A modified compound scanning surface (p < 0.05). Higher intensities of ambient light in the scanning room were associated with reduced scanning efficacy (p < 0.05). Moreover, the scanner showed greater amounts of undetected volume as the degrees of crowding and mesial tipping of the lower second molar increased over 25°, with mean error values of 0.97 mm3 and 1.12 mm3, respectively. (4) Conclusions: For scanning procedures employing digital acquisition, differences in the degrees of crowding and mesial tipping of the lower second molar, scanning surface material, and external light source intensity influence the efficacy and efficiency of the scanning procedures, scanning chair-time, scanning failures, and undetected volume.

scholarly journals An in-vitro study to evaluate the accuracy of dies obtained from dual arch impression trays using addition silicone impression material and tray combinations

2015 ◽  
Vol 12 (2) ◽  
pp. 111-117
Author(s):  
P K Parajuli ◽  
S George ◽  
V Shenoy
Keyword(s):  
In Vitro Study ◽  
Dimensional Accuracy ◽  
Acrylic Resin ◽  
Simultaneous Recording ◽  
T Test ◽  
Impression Material ◽  
Tooth Preparation ◽  
Made In ◽  
Plastic Trays

Background: Dual-arch impression technique allows the simultaneous recording of  tooth preparation, opposing anatomic tooth and maxillomandibular relationship. The  accuracy of reproduction of this easy and quick technique, however, has not been  studied in detail in past. Objective: To compare the accuracy of the impressions  made by using the same impression material in dual arch plastic trays, dual-arch  metal trays and acrylic resin custom trays. Methods: The dies obtained from the  addition silicone impressions made in dual-arch plastic trays, dual-arch metal trays  and full arch acrylic resin custom trays were compared for the dimensional accuracy  with the prepared typodont tooth as a control. Student’s paired t-test and unpaired  t-test were used for the data analyses using the Statistical Package for Social Studies  (SPSS) version 11.5. Results: The dies obtained from all the impression combinations  showed increased dimension (acrylic resin custom trays 9.4 mm±0.048, dual-arch  plastic trays 9.5 mm±0.035, dual-arch metal trays 9.41 mm±0.017) as compared to  the dimension of control (9.39 mm±0.007). Conclusion: All the tray-impression  material combinations showed variable accuracies. Full arch acrylic resin trays  resulted in greatest accuracy whereas dual-arch plastic trays the least accuracy.Health Renaissance 2014;12(2):  pp: 111-117

scholarly journals Fluoride Concentration in SDF Commercial Products and Their Bioavailability with Demineralized Dentine

2020 ◽  
Vol 31 (3) ◽  
pp. 257-263
Author(s):  
Aline Laignier Soares-Yoshikawa ◽  
Jaime Aparecido Cury ◽  
Cínthia Pereira Machado Tabchoury
Keyword(s):  
Fluoride Concentration ◽  
In Vitro Study ◽  
Test Strip ◽  
T Test ◽  
The Other ◽  
Alkaline Ph ◽  
Commercial Products ◽  
Silver Diamine Fluoride ◽  
Direct Technique

Abstract The aim of this in vitro study was to determine the fluoride concentration in silver diamine fluoride (SDF) products and their bioavailability with demineralized dentine. The products evaluated (expected fluoride concentrations) were: I: Saforide 38% (45,283 ppm F); II: Advantage Arrest 38.3 to 43.2% (45,283 to 51,013 ppm F); III: Ancárie 12% (14,100 ppm F); IV: Ancárie 30% (35,400 ppm F), V: Cariestop 12% (14,100 ppm F) and VI: Cariestop 30% (35,400 ppm F). The fluoride concentration was evaluated using an ion-specific electrode (ISE) by direct technique, which was confirmed after microdiffusion. The pH of the products was determined with a pH test strip. For the bioavailability test, demineralized dentine slabs were treated with one of the products for 1 min. Loosely (CaF2-like) and firmly-bound fluoride (FAp) were determined. The fluoride concentration found in the products (mean±SD; ppm F) by the ISE direct technique was: I:53,491±554; II:57,249±1,851; III:4,814±268; IV:5,726±43; V:10,145±468; VI:11,858±575; these values were confirmed after microdiffusion (t-test; p>0.05) and disagree with the declared by the manufacturers. The pH of Ancárie 12 and 30% was 6.0 and 4.5, respectively, in disagreement with the alkaline pH expected for SDF solution and found in the other products evaluated. There was no correlation between either CaF2-like (r=0.221; p=0.337) or FAp (r=-0.144; p=0.830) formed in demineralized dentine and fluoride concentration found in the products. The problems of pH and fluoride concentration found in available professional commercial SDF products suggest that they are not under sanitary surveillance.

scholarly journals A Comparative Analysis of the Piezoelectric Ultrasonic Appliance and Trephine Bur for Apical Location: An In Vitro Study

2021 ◽  
Vol 11 (10) ◽  
pp. 1034
Author(s):  
Esther Cáceres Madroño ◽  
Paulina Rodríguez Torres ◽  
Soraya Oussama ◽  
Álvaro Zubizarreta-Macho ◽  
María Bufalá Pérez ◽  
...  
Keyword(s):  
Study Groups ◽  
Experimental Models ◽  
Site Preparation ◽  
T Test ◽  
Entry Point ◽  
Osteotomy Site ◽  
End Point ◽  
Planning Software ◽  
Preparation Techniques

To compare and contrast the accuracy of piezoelectric ultrasonic insert (PUI) and trephine bur (TB) osteotomy site preparation techniques for apical location. (1) Material and methods: A total of 138 osteotomy site preparations were randomly distributed into one of two study groups. Group A: TB technique (n = 69) and B: PUI technique (n = 69). A preoperative cone-beam computed tomography scan and an intraoral scan were performed and uploaded to implant-planning software to plan the virtual osteotomy site preparations for apical location. Subsequently, the osteotomy site preparations were performed in the experimental models with both osteotomy site preparation techniques and a postoperative CBCT scan was performed and uploaded into the implant-planning software and matched with the virtually planned osteotomy site preparations to measure the deviation angle and horizontal deviation as captured at the coronal entry point and apical end-point between osteotomy site preparations using Student’s t-test statistical analysis. (2) Results: The paired t-test found statistically significant differences at the coronal entry-point deviations (p = 0.0104) and apical end-point deviations (p = 0.0104) between the TB and PUI study groups; however, no statistically significant differences were found in the angular deviations (p = 0.309) between the trephine bur and piezoelectric ultrasonic insert study groups. (3) Conclusions: The results showed that the TB is more accurate than the PUI for apical location.

scholarly journals Effect of Tannic Acid on Bond Strength of Etch and Rinse and Self-etch Adhesive Systems in Dentin of Primary Teeth

2017 ◽  
Vol 18 (1) ◽  
pp. 34-38
Author(s):  
Mojtaba Abdollahi ◽  
Masoumeh Ebrahimi ◽  
Alireza Sarraf Shirazi ◽  
Faraneh Abdolhoseinpour
Keyword(s):  
Bond Strength ◽  
Tannic Acid ◽  
Primary Teeth ◽  
Testing Machine ◽  
T Test ◽  
Adhesive Systems ◽  
Primary Molar ◽  
Etch And Rinse ◽  
Self Etch

ABSTRACT Introduction One of the possible mechanisms for the gradual destruction of bond strength in dentin-resin interface, could be due to the demineralized unstable collagen matrix. Use of protease inhibitors, such as tannic acid (TA) could prevent destruction of collagen fibers. The aim of this study was to compare the TA effect on bond strength of etch and rinse and self-etch adhesive systems in the dentin of primary teeth. Materials and methods This in vitro study was done on 40 extracted primary molar teeth. The teeth were sectioned in the mesiodistal direction, and enamel of buccal and lingual surfaces was removed. Samples were randomly divided into four groups: Single bond (SB) + TA, SB, Clearfil SE Bond (CSB) + TA, and CSB. Then, Z250 and Clearfil AP-X composites were cured on the surfaces of SB and CSB groups respectively. After that, all samples were divided into aging and non-aging groups. For 3 months, samples were placed under 1,000 thermal cycles in aging group. Subsequently, the shear bond strengths of all groups were measured by the International testing machine, and failure mode was evaluated by an optical stereomicroscope. Data were analyzed with paired t-test and independent t-test. Results Tannic acid induced a significant reduction in the immediate bond strength of adhesive SB. Meanwhile, TA had no significant effect on shear bond strength of the CSB system. Conclusion Based on our findings, use of TA is not recommended with SB and CSB adhesives on primary teeth. Clinical significance Tannic acid may not be considered in resin restorations of primary teeth. How to cite this article Ebrahimi M, Sarraf Shirazi A, Abdolhoseinpour F, Abdollahi M. Effect of Tannic Acid on Bond Strength of Etch and Rinse and Self-etch Adhesive Systems in Dentin of Primary Teeth. J Contemp Dent Pract 2017;18(1):34-38.

scholarly journals Intratubular Enterococcus faecalis viability assessment following root canal instrumentation with rotary and reciprocating systems via fluorescence microscopy

2020 ◽  
Vol 14 (4) ◽  
pp. 214-217
Author(s):  
Jamileh Ghoddusi ◽  
Ehsan Arian ◽  
Maryam Golmohammadi ◽  
Maryam Gharechahi ◽  
Siavash Moushekhian
Keyword(s):  
Enterococcus Faecalis ◽  
In Vitro Study ◽  
Sampling Procedure ◽  
T Test ◽  
Root Canals ◽  
Paired Samples ◽  
Viable Bacteria ◽  
Root Canal Instrumentation ◽  
Reciprocating Systems

Background. The present in vitro study aimed to compare the effectiveness of the WaveOne and ProTaper Gold systems in removing the Enterococcus faecalis biofilm. Methods. Thirty-eight mandibular premolars were selected. The root canals were assigned to standard control (canals serially enlarged with ProTaper Gold S1-S2-F1-F2, n=15) and experimental (canals enlarged with Primary WaveOne file, n=15) groups. Following the instrumentation procedure, the root canals underwent a sampling procedure, and the colonyforming unit (CFU) counts were determined. The samples were also evaluated under a fluorescent microscope to evaluate viable bacteria. The data were analyzed using independent samples t test and paired samples t test. Results. The results showed that, compared with the ProTaper group, the WaveOne group exhibited the least viable bacteria (P=0.004). Conclusion. It was concluded that comparison with the ProTaper Gold rotary system, the WaveOne reciprocating file is more successful in reducing intratubular viable bacteria counts.

scholarly journals Vascular-dependent effects of elevated glucose on postganglionic sympathetic neurons

2011 ◽  
Vol 300 (4) ◽  
pp. H1386-H1392 ◽  
Author(s):  
Deborah H. Damon
Keyword(s):  
Vascular Function ◽  
Sympathetic Neurons ◽  
Vascular Complications ◽  
Sympathetic Nerves ◽  
T Test ◽  
Neuronal Cultures ◽  
Elevated Glucose ◽  
Low Glucose

Perivascular sympathetic nerves are important determinants of vascular function that are likely to contribute to vascular complications associated with hyperglycemia and diabetes. The present study tested the hypothesis that glucose modulates perivascular sympathetic nerves by studying the effects of 7 days of hyperglycemia on norepinephrine (NE) synthesis [tyrosine hydroxylase (TH)], release, and uptake. Direct and vascular-dependent effects were studied in vitro in neuronal and neurovascular cultures. Effects were also studied in vivo in rats made hyperglycemic (blood glucose >296 mg/dl) with streptozotocin (50 mg/kg). In neuronal cultures, TH and NE uptake measured in neurons grown in high glucose (HG; 25 mM) were less than that in neurons grown in low glucose (LG; 5 mM) ( P < 0.05; n = 4 and 6, respectively). In neurovascular cultures, elevated glucose did not affect TH or NE uptake, but it increased NE release. Release from neurovascular cultures grown in HG (1.8 ± 0.2%; n = 5) was greater than that from cultures grown in LG (0.37 ± 0.28%; n = 5; P < 0.05; unpaired t-test). In vivo, elevated glucose did not affect TH or NE uptake, but it increased NE release. Release in hyperglycemic animals (9.4 + 1.1%; n = 6) was greater than that in control animals (5.39 + 1.1%; n = 6; P < 0.05; unpaired t-test). These data identify a novel vascular-dependent effect of elevated glucose on postganglionic sympathetic neurons that is likely to affect the function of perivascular sympathetic nerves and thereby affect vascular function.

scholarly journals A COMPARATIVE EVALUATION OF MICROLEAKAGE, COMPRESSIVE STRENGTH, FLEXURAL STRENGTH AND FLUORIDE RELEASE OF ZIRCONOMER AND KETAC SILVER: AN IN VITRO STUDY.

2020 ◽  
Vol 9 (4) ◽  
Author(s):  
CHARANTEJA VEMAGIRI ◽  
Uloopi KS ◽  
Vinay Chandrappa ◽  
Anusha Ch
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Testing Machine ◽  
In Vitro Study ◽  
Biological Properties ◽  
T Test ◽  
Fluoride Release ◽  
Restorative Material ◽  
Glass Ionomer

Background: A successful restorative material forms a better adhesion, resist the microleakage and releases fluoride. However, existing glass ionomer cements cannot be used as a posterior restorative material in stress bearing areas. A new ionomer called Zirconomer, zirconia reinforced glass ionomer claims to exhibit high physical and biological properties. Aim: To assess and compare the microleakage, compressive strength, flexural strength and fluoride release from zirconomer with ketac silver. Materials & Methods: On twenty caries free premolar teeth (10 per each group), a class v cavity was restored with zirconomer and ketac silver. The microleakage was assessed using dye penetration test and stereomicroscope. The compressive and flexural strengths of these materials were measured using Instron Universal testing machine. The amount of fluoride released from the modified ionomers at pH 5 and pH 7 was estimated using Orion fluoride specific electrode. The obtained data was then subjected to statistical analysis. Results: Data was analysed using paired t-test for intergroup comparisons and unpaired t-test for intragroup comparisons. The overall microleakage (0.5±0.48) of zirconomer was significantly less (p=0.000) compared to ketac silver (1.9±0.83). Zirconomer demonstrated a significant higher compressive strength (330.25±60.14), flexural strength (33.058±2.36) than ketac silver (p= 0.000). Zirconomer demonstrated high fluoride release from day 1 to day 7 at both pH 5 and pH 7. Conclusion: Zirconomer demonstrated better physical and biological properties compared with ketac silver.

18 EMBRYO AGGREGATION IN PIG IMPROVES CLONING EFFICIENCY AND EMBRYO QUALITY

2016 ◽  
Vol 28 (2) ◽  
pp. 139
Author(s):  
C. Buemo ◽  
A. Gambini ◽  
L. Moro ◽  
R. F. Y. Martin ◽  
D. Salamone
Keyword(s):  
In Vitro Culture ◽  
Dna Fragmentation ◽  
Embryo Development ◽  
Embryo Quality ◽  
T Test ◽  
Control Group ◽  
Reconstructed Embryo ◽  
Student’S T ◽  
Student’S T Test

In this study, we analysed the effects of the cloned embryo aggregation on in vitro embryo development and embryo quality by measuring blastocyst size and cell number, DNA fragmentation levels by TUNEL assay, and the relative expression of genes associated with pluripotency, apoptosis, trophoblast markers, and DNA methylation in the porcine. Cumulus-oocyte complexes were recovered from slaughterhouse ovaries by follicular aspiration. Maturation was performed in TCM for 42 to 48 h at 39°C and 5% CO2. After denudation by treatment with hyaluronidase, mature oocytes were stripped of the zona pellucida using a protease and then enucleated by micromanipulation; staining was performed with Hoëchst 33342 to observe metaphase II. Ooplasms were placed in phytohemagglutinin to permit different membranes to adhere between each other; the ooplasm membrane was adhered to a porcine fetal fibroblast from an in vitro culture. Adhered membranes of the donor cell nucleus and enucleated oocyte cytoplasm were electrofused through the use of an electric pulse (80 V for 30 μs). All reconstituted embryos were electrically activated using an electroporator in activation medium (0.3 M mannitol, 1.0 mM CaCl2, 0.1 mM MgCl2, and 0.01% polyvinyl alcohol) by a DC pulse of 1.2 kVcm for 80 μs. Then, embryos were incubated in 2 mM 6-DMAP for 3 h. In vitro culture of zona-free embryos was achieved in a well of wells system in 100 μL of SOF medium. Two experimental groups were used, one control group with a single reconstructed embryo per microwell (1×) and the other group placing 3 reconstructed embryo per microwell (3x aggregation group). Embryos were cultivated at 39°C in 5% O2, 5% CO2 for 7 days in SOF medium with a supplement of 10% fetal bovine serum on the fifth day. At Day 7, resulting blastocysts were classified according to their morphology and diameter to determine their quality. Our results showed that aggregation of 3× embryos increased blastocyst formation rate and blastocyst size of pig cloned embryos (Fisher’s test P < 0.05 and Student’s t-test P < 0.05, respectively). The DNA fragmentation levels in 3× aggregated cloned blastocysts were significantly decreased compared to 1x blastocyst (Student’s t-test P < 0.05). Levels of Oct4, Klf4, Igf2, Bax, and Dnmt1 transcripts were significantly higher in aggregated embryos, whereas Nanog levels were not affected. Transcripts of Cdx2 and Bcl-xl were essentially nondetectable (Student’s t-test P < 0.05). Our study suggests that embryo aggregation in the porcine may be beneficial for cloned embryo development and embryo quality, through a reduction in apoptotic levels and an improvement in cell reprogramming.

26 Drugs that Modify Epigenetics...What do they do to Porcine Clones?

2018 ◽  
Vol 30 (1) ◽  
pp. 152
Author(s):  
C. P. Buemo ◽  
A. Gambini ◽  
L. N. Moro ◽  
N. Canel ◽  
D. F. Salamone
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Electric Pulse ◽  
Donor Cell ◽  
T Test ◽  
Control Group ◽  
Developmental Rates ◽  
Student’S T ◽  
Student’S T Test

Although somatic cell nuclear transfer (SCNT) technology was developed more than 20 years ago, cloning efficiency remains low. Failures in the reprogramming of the donor cell result in embryos with aberrant epigenetic patterns and low developmental rates. In this study, we assessed whether the use the inhibitor of DNA (cytosine 5) methyltransferase 5-azacitidine (5Aza) combined with the MEK inhibitor in the MAPK pathway PD0325901 (PD) could improve SCNT efficiency in pigs. In vitro maturation of cumulus–oocyte complexes was performed in TCM for 44 h at 39°C under 5% CO2. Cumulus cells and zona pellucida was removed from matured oocytes, followed by enucleation of the metaphase plate previously stained with Hoëchst 33342. Each enucleated oocyte was attached to a donor cell by phytohemagglutinin treatment followed by an electric pulse of 80V for 30 μs. After fusion, reconstituted embryos were activated by an electric pulse followed by an incubation in 2 mM 6-DMAP for 3 h. Cloned embryos were cultured in vitro in a modified well-of-well system in SOF medium, where 3 cloned embryos were placed per microwell (3X). The experimental group 3X + drugs was exposed for the first 3 days to 1 μM PD and 1 μM 5Aza in SOF medium. After washing, embryos were cultured until Day 7 in regular SOF medium. The control group (3X) was cultured in regular SOF medium for 7 days. In vitro embryo developmental rates, gene expression, histone acetylation, and DNA methylation status were studied. The use of epigenetic modifying drugs significantly increased blastocyst rates (40.9% v. 29%; Fisher’s test, P < 0.05) and embryo size (41.46% v. 28.56%; Student’s t-test, P < 0.05) compared with the control group. Regarding gene expression, an increase of the relative expression of genes related to cell differentiation (Igf2 and Cdx2), antiapoptotic pathways (Bcl-xl) and DNA methylation modulation (Mapk1) was observed (P < 0.05). Pluripotency genes Oct4 and Nanog did not show differences between groups. The Bax proapoptotic gene significantly decreased its expression after drug treatment, as did the Klf4 gene (P < 0.05). Results were analysed by Student’s t-test. According to Histone H3K27ac, which is associated with enhancers or gene promoters, its marker was located mainly in the nuclear periphery respect to the control group with a uniform dispersion, indicating that the treatment could be activating certain genes by locating them near the periphery. Histone H3K4me1 was more uniformly localised throughout the nucleus in both groups. The intensity of the fluorescence was measured by quantitative confocal microscopy using a histogram produced by the ImageJ program (National Institutes of Health, Bethesda, MD, USA). Regarding DNA methylation by bisulphite sequencing, the 2 genes studied (Oct4 and DNMT1) showed a higher demethylation status for the treated group. Our results indicate that the combination of 5Aza+PD during early pre-implantation development dramatically increase blastocyst rates and embryo quality. This novel combination could be used as a strategy to improve the efficiency of SCNT in pigs and potentially other animals.

scholarly journals Feasibility of 3-Dimensional Visual Guides for Preparing Pediatric Zirconia Crowns: An In Vitro Study

2020 ◽  
Vol 17 (16) ◽  
pp. 5732
Author(s):  
Ho Yeon Kang ◽  
Hyeonjong Lee ◽  
Yong Kwon Chae ◽  
Seoung-Jin Hong ◽  
Yun Yeong Jeong ◽  
...  
Keyword(s):  
Three Dimensional ◽  
In Vitro Study ◽  
Mixed Dentition ◽  
Preparation Time ◽  
Second Molar ◽  
Significant Difference ◽  
Distal Surface ◽  
Zirconia Crowns ◽  
Tooth Preparation

This study evaluated the feasibility of a tooth preparation guide for prefabricated zirconia crowns (PZCs). Three-dimensional surface data for PZCs of the left maxillary primary first molar and left mandibular primary second molar were obtained using a model scanner. The tooth preparation data were digitally designed to harmonize with the adjacent teeth on the mixed dentition model and visualized using a color-coded map, which presents the required amount of tooth reduction. Twenty participants were recruited for preparing teeth with and without using the tooth preparation guide. The following three parameters were evaluated: tooth preparation time, harmony score, and amount of tooth reduction. The preparation time when using the guide was significantly reduced (p < 0.05), and a significant difference was observed in the harmony scores for the maxillary primary first molar preparation. Furthermore, the amount of tooth reduction was significantly different for both maxillary and mandibular primary molars (p < 0.05) in terms of the occlusal distal surface and buccal line angle in the maxillary primary first molars, and the smooth surfaces, proximal surfaces, and mesial line angles in the mandibular primary second molars. Thus, the results suggest that a tooth preparation guide could facilitate better tooth preparation for PZCs.

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