scholarly journals In Vitro Evaluation of Desensitizing Agents Containing Bioactive Scaffolds of Nanofibers on Dentin Remineralization

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1056
Author(s):  
Natália Bastos-Bitencourt ◽  
Marilia Velo ◽  
Tatiana Nascimento ◽  
Cassiana Scotti ◽  
Maria Gardennia da Fonseca ◽  
...  
Keyword(s):  
Statistical Significance ◽  
The Other ◽  
Fluoride Varnish ◽  
Confocal Laser ◽  
Dentinal Tubules ◽  
Bioactive Scaffolds ◽  
Dentin Permeability ◽  
Desensitizing Agents ◽  
Acid Challenge

This study evaluated the effect of the incorporation of bioactive nanofibers in desensitizing agents on dentin permeability. Sixty disks of dentin were randomly distributed in four groups (n = 15). Distribution was based on the desensitizing agents, fluoride varnish and self-etching adhesive, and the presence of nanofibers: C (self-etching adhesive Clearfil SE Bond), CN (Clearfil SE Bond with 1% nanofiber), D (Duraphat varnish), and DN (Duraphat varnish with 1% nanofiber). Dentin permeability was determined using hydraulic conductivity. For a qualitative analysis, confocal laser microscopy and scanning electron microscopy were performed. The C group showed the lowest hydraulic conductance (Lp%) (89.33), while the DN group showed the highest Lp% (116.06). No statistical significance was observed in the Lp% values in all groups after the treatment and 6% citric acid challenge (p > 0.239). In the images, the CN group presented a higher superficial and intratubular deposition. In addition, this group presented a more homogeneous dentin surface and wide occlusion of dentinal tubules than the other treatments. Despite there being no statistical differences among the treatments employed, the images showed that the CN group presented a higher surface and intratubular deposition compared to the other treatments, even after the acid challenge.

scholarly journals Effect of commercially available and experimental potassium oxalate-based dentin desensitizing agents in dentin permeability: influence of time and filtration system

2006 ◽  
Vol 17 (4) ◽  
pp. 300-305 ◽  
Author(s):  
Sérgio Lima Santiago ◽  
José Carlos Pereira ◽  
Ana Christina Bonato Figueiredo Martineli
Keyword(s):  
Hydraulic Conductance ◽  
Potassium Oxalate ◽  
Group V ◽  
Significance Level ◽  
Group Iii ◽  
Dentin Permeability ◽  
Group I ◽  
Filtration System ◽  
Desensitizing Agents

This study evaluated the influence of time after application of oxalate solutions in reducing dentin hydraulic conductance. Fifty dentin discs were obtained from extracted human third molars and assigned to 5 groups (n=10), according to the desensitizing agent used: Group I: OxaGel; Group II: experimental agent DD-1: Group III: experimental agent DD-2. In Groups IV and V, a placebo gel and deionized water were used as control, respectively. The agents were applied for 3 min, washed out and the hydraulic conductance was measured immediately and at 5-, 15- and 30-min intervals, and after acid etching. Data were analyzed statistically by two-way ANOVA and Duncan's test at 5% significance level. Groups I, II and III did not differ significantly from each other in any of the time intervals (p>0.05). Likewise, Groups IV and V were statistically similar to each other (p>0.05). The active agents reduced significantly dentin permeability in comparison to control groups (p<0.05). Dentin permeability measured in vitro decreased significantly with time regardless of the agent applied (either active or control agents). The results of Group V, in which no dentin desensitizing agent was employed, indicates that the assessment of dentin permeability by this method must be interpreted with caution.

A comparative analysis between Nd:YAG and CO2lasers for their sealing ability of dentinal tubules with and without fluoride varnish: An in vitro study

2012 ◽  
Vol 6 (2) ◽  
pp. 51
Author(s):  
DeepaV Kumar ◽  
Ramanathan Meyappan ◽  
Babu Sreenadh ◽  
Shafie Ahamed ◽  
Natanasikamani Gurucharan ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
In Vitro Study ◽  
Vitro Study ◽  
Fluoride Varnish ◽  
Dentinal Tubules ◽  
Sealing Ability

131 APOPTOSIS AND DEVELOPMENT OF IN VITRO-PRODUCED BOVINE EMBRYOS EXPOSED TO SUPRAPHYSIOLOGICAL CONCENTRATIONS OF INSULIN-LIKE GROWTH FACTOR-1 (IGF-1)

2009 ◽  
Vol 21 (1) ◽  
pp. 165
Author(s):  
M. A. Velazquez ◽  
H. Niemann
Keyword(s):  
Laser Scanning ◽  
Apoptotic Cell ◽  
Polycystic Ovary ◽  
Statistical Significance ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Control Group ◽  
Fisher Exact Test ◽  
Bovine Embryos

It has been hypothesized that high non-physiological IGF-1 levels are partially responsible for the recurrent pregnancy loss observed in women with the polycystic ovary syndrome (Eng GS et al. 2007 Diabetes 56, 2228–2234). The aim of this study was to determine the effect of supraphysiological concentrations of IGF-1 on blastocyst production and the occurrence of apoptosis in bovine embryos, which are a good model for human embryo development (Baumann CG et al. 2007 Mol. Reprod. Dev. 74, 1345–1353). COC obtained by slicing from abattoir ovaries were matured (TCM-199, Sigma) for 24 h and fertilized (Fert-TALP) for 18 h (Day 0) in vitro. Two different IGF-1 (Recombinant human IGF-1, R&D Systems GmbH, Wiesbaden, Germany) concentrations (supraphysiological = 1000 ng mL–1 and physiological = 100 ng mL–1) were added to the culture media (Synthetic oviduct fluid/BSA) and compared with a control group (no IGF-1 supplementation). On Day 8, blastocyst rates (22 replicates) were recorded and DNA degradation was detected in blastocyst nuclei using a cell death detection kit (Roche Diagnostics GmbH, Mannheim, Germany) based on the terminal deoxinucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) principle. Embryos (n = 27 [control], n = 29 [both IGF-1 groups]) from 4 replicates were examined by confocal laser scanning microscopy. Data were analyzed by ANOVA and the Fisher exact test using the SigmaStat 2.0 software package (Jandel Scientific, San Rafael, CA). Cleavage was numerically improved by both, 1000 (59.1 ± 1.8) and 100 (58.2 ± 2.8) ng IGF-1 over controls (53.5 ± 2.2), but the differences did not reach statistical significance (P = 0.22). The proportion of hatched blastocysts was enhanced by 100 (5.8 ± 1.0, P = 0.03) and 1000 (5.1 ± 0.7, P = 0.03) ng IGF-1 compared to controls (2.8 ± 0.6). Total blastocyst rate was increased by 100 ng IGF-1 (34.4 ± 1.9, P = 0.02) over controls (28.3 ± 1.7), but not by 1000 ng IGF-1 (29.1 ± 1.6 P = 0.75). The 100 ng IGF-1 group (38.5 ± 3.7) had fewer degenerated embryos (P = 0.01) compared to 1000 ng IGF-1 (49.7 ± 3.3). The proportion of embryos displaying at least one apoptotic cell was greater in the 1000 ng IGF-1 group over controls (96% v. 77% P = 0.04). The number of blastomeres with TUNEL-positive nuclei per embryo was higher in the supraphysiological group (5.5 ± 0.6, P < 0.001) compared with the control (2.3 ± 0.4) and the physiological group (2.5 ± 0.3). There were no significant differences between the control and the 100 ng IGF-1 group in this regard (P = 0.49). In conclusion, supraphysiological concentrations of IGF-1 do not increase blastocyst production but increase levels of apoptosis in bovine embryos produced in vitro. M. A. V. is in the PhD program of the University of Veterinary medicine, Hannover, Germany, and is supported by the German Academic Exchange Service (DAAD)

Activity of quinfamide against natural infections of Entamoeba criceti in hamsters: a new potent agent for intestinal amoebiasis

Parasitology ◽  
1980 ◽  
Vol 81 (1) ◽  
pp. 157-168 ◽  
Author(s):  
R. G. Slighter ◽  
A. Yarinsky ◽  
H. P. Drobeck ◽  
D. M. Bailey
Keyword(s):  
Single Dose ◽  
Adverse Effects ◽  
Total Dose ◽  
Statistical Significance ◽  
Parent Compound ◽  
The Other ◽  
Daily Administration ◽  
Intestinal Amoebiasis ◽  
Tissue Changes

SUMMARYA novel tetrahydroquinolinyl ester, quinfamide, administered orally in multiple doses for 3 days had an ED50, of 0·25 mg/kg/day (total dose 0·75 mg/kg) for eradicating Entamoeba criceti in hamsters in several tests. It was significantly more active by direct comparison than 3 commercially available amoebicides and at least as active as 2 other esters of the parent compound, 1-(dichloroacetyl)-1,2,3,4-tetrahydro-6-quinonnol. After administration of a single dose, ED50, calculations for quinfamide averaged 0·9 mg/kg. Quinfamide was considerably more active than the other tetrahydroquinolinols, diloxanide furoate and teclozan, and it was approximately 1·5 times more active than etofamide; a statistical significance between the latter 2 drugs could be demonstrated in one of 4 tests. Administered prophylactically, quinfamide was shown to protect hamsters from re-infection with E. criceti. It also inhibited propagation of E. histolytica in vitro at a concentration of 20 /tg/ml. No adverse effects were noted in rodents after a single dose as high as 10 g/kg. Daily administration to monkeys of doses up to 500 mg/kg for as long as 37 days produced no pharmacological aberrations during or after medication; haematological studies and urine analyses were normal and no gross or microscopical tissue changes attributable to quinfamide were observed. No toxicity was revealed following acute (2 g/kg) and chronic (500 mg/kg/day × 31 days) administration of the drug to dogs and rats, respectively.

scholarly journals Efeito da aplicação prévia ou adição de dessensibilizantes em géis de peróxido de hidrogênio no esmalte clareado

2021 ◽  
Vol 10 (7) ◽  
pp. e18610716467
Author(s):  
Vinicius Matheus Amorim Macêdo ◽  
Mariana Evangelista Santos ◽  
Rosângela Marques Duarte ◽  
Sônia Saeger Meireles
Keyword(s):  
Vickers Microhardness ◽  
In Vitro Study ◽  
Potassium Nitrate ◽  
The Other ◽  
Color Measurement ◽  
Whitening Effect ◽  
Treatment Groups ◽  
Desensitizing Agents ◽  
Bleaching Gels

This in vitro study evaluated the effect of 35% hydrogen peroxide (35HP) gels with different desensitizing agents on color, microhardness and roughness of bleached enamel. Forty enamel-dentin specimens (6x6x2 mm2) were obtained from twenty human molars. After color measurement with a spectrophotometer, the specimens were randomized into four groups (n= 10): 35HPw- 35HP without desensitizing agent; 35HPCa- 35HP with calcium; 35HPK- 35HP with 0.5% potassium nitrate; 35HPTFa- 35HPw + topical application of 5% potassium nitrate and 2% sodium fluoride (TFa). Specimens were evaluated for color (∆Eab* and ∆E00), Vickers microhardness (VHN) and, superficial and volumetric roughness (Ra and Sa, µm) using a 3D non-contact profilometer before and 1-week after bleaching. Data were analyzed by ANOVA and Tukey tests (p< 0.05). Both treatment groups promoted a significant whitening effect and there was no difference between them for any color parameters evaluated. All groups reduced significantly the VHN, but the 35HPK showed a reduction significantly major than the other groups. 35HPCa and 35HP+TFa did not avoid the of Ra and Sa increasing. It can be concluded that 35HP bleaching gels with different desensitizing agents did not affect the whitening efficacy. However, all treatments decreased the microhardness, the addition of calcium into 35HP gel and the application of TFa before bleaching did not revert the enamel roughness under in vitro conditions.

Experimental Analysis of the Quality of Needle-Assisted Fenestration in Aortic Stent-Grafts and the Differences Between Gradual and Rapid Balloon Dilation

2020 ◽  
pp. 152660282094709 ◽  
Author(s):  
Dong-lin Li ◽  
Qing-long Zeng ◽  
Yi-lang Xiang ◽  
Chen-yang Qiu ◽  
Zhen-jiang Li ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Balloon Dilation ◽  
The Other ◽  
Maximum Diameter ◽  
Stent Grafts ◽  
Large Balloon Dilation ◽  
Length And Area ◽  
Fabric Tears

Purpose: To report the findings of an in vitro experiment to evaluate the quality of needle fenestrations dilated by different size balloons in various stent-grafts and to investigate the differences between gradual and rapid dilation. Materials and Methods: Fenestrations were made using an 18-G needle in 5 different polyester or expanded polytetrafluoroethylene (ePTFE) stent-grafts: Relay, Valiant, Hercules, TAG, and Ankura. Each stent-graft received 2 groups of fenestrations: one was followed by gradual sequential dilation (4-, 6-, 8-, and 10-mm balloons) and the other by rapid dilation (4- and 10-mm balloons). The pressure was increased to 10 atmospheres or until the balloon was fully inflated with no waist. Quantitative and qualitative evaluations, including fenestration diameter, area, shape, and margins were conducted using light microscopy and scanning electron microscopy. Results: Relay had the strongest resistance to dilation and Ankura the slightest. The maximum length and area of holes expanded as the balloon diameter increased. The fenestrations in polyester devices were mostly elliptical or slit-like, with limited tears but extensive fibers visible in the margin, while ePTFE stent-grafts showed larger fenestration areas with clearer margins. Ankura showed the best quality of fenestrations, which were always circular or square without fabric tears, while the holes in the TAG were square or elliptical but sometimes had a slit after large balloon dilation (≥6 mm). The Relay, Valiant, Hercules, and Ankura devices showed no difference in maximum diameter, fenestration area, or scores of shape and margin (p>0.05). Rapid dilation in the TAG increased the rate of uncontrolled fabric tear, resulting in a larger final diameter (12.90 vs 10.82 mm, p=0.047), smaller area (30.46 vs 41.09 mm2, p=0.028), worse shape (0.75 vs 1.20, p=0.268), and worse margin (0.40 vs 1.00, p=0.174). Though the decreased fenestration shape and margin scores did not reach statistical significance, the trend for decline was more obvious than with the other devices. Conclusion: Materials and structures of the stent-grafts determine the quality of fenestrations dilated by different size balloons. The use of sequential vs rapid balloon dilation is also crucial for fashioning high-quality fenestrations and should be selected judiciously.

scholarly journals In Vitro comparison of cyclic fatigue resistance of TruNatomy in single and double curvature canals compared with different nickel-titanium rotary instruments

2019 ◽  
Author(s):  
Amr M. Elnaghy ◽  
Shaymaa E Elsaka ◽  
Ayman Mandorah
Keyword(s):  
Fatigue Resistance ◽  
Statistical Significance ◽  
Cyclic Fatigue ◽  
The Other ◽  
Probability Of Survival ◽  
Double Curvature ◽  
Significant Difference ◽  
Vortex Blue ◽  
Number Of Cycles

Abstract Background The purpose of this study was to compare the cyclic fatigue resistance of newly developed TruNatomy instruments (TRN) in single and double (S-shaped) curvature canals with HyFlex CM (HCM), Vortex Blue (VB) and RaCe (RC) instruments.Methods Size 20/0.04 taper and size 25/0.04 of HCM, VB and RC were used. For TRN instruments, size 20/0.04 taper (small) and size 26/0.04 taper (prime) were used. The instruments were tested in artificial canals with double curvature (coronal curve; 60° curvature, 5 mm radius and apical curve; 70° curvature and 2 mm radius) and single curvature (60° curvature, 5 mm radius). The number of cycles to failure (NCF) was recorded. Data were statistically analyzed and Weibull analysis was performed on NCF data. Statistical significance was set at p < 0.05.Results TRN and HCM revealed significantly higher NCF compared with the other instruments for both tested sizes in single and double curvature canals ( p < 0.05). TRN and HCM showed no significant difference in the NCF ( p > 0.05). The probability of survival was higher for HCM and TRN instruments than VB and RC instruments.Conclusion HCM and TRN instruments were more resistance to cyclic fatigue than VR and RC instruments in single and double curvature canals. HCM and TRN instruments were anticipated to survive with higher number of cycles than the other tested instruments. RC instrument had the lowest fatigue resistance than the other instruments.

The Dentin Disc Surface: A Plausible Model for Dentin Physiology and Dentin Sensitivity Evaluation

1997 ◽  
Vol 11 (4) ◽  
pp. 487-501 ◽  
Author(s):  
D.G. Gillam ◽  
N.J. Mordan ◽  
H.N. Newman
Keyword(s):  
Screening Method ◽  
Hydrodynamic Theory ◽  
Treatment Modalities ◽  
Ongoing Research ◽  
Dentin Permeability ◽  
Dentin Surface ◽  
Dentin Sensitivity ◽  
Desensitizing Agents ◽  
Tubule Occlusion

Dentin sensitivity (DS) is a painful clinical condition which may affect 8-35% of the population. Various treatment modalities have claimed success in relieving DS, although at present there does not appear to be a universally accepted desensitizing agent. Current opinion based on Brannstrom's Hydrodynamic Theory would suggest that following exposure of the dentin surface (through attrition, abrasion, or erosion), the presence of open dentinal tubules, patent to the pulp, may be a prerequisite for DS. The concept of tubule occlusion as a method of dentin desensitization, therefore, is a logical conclusion from the hydrodynamic theory. The fact that many of the agents used clinically to desensitize dentin are also effective in reducing dentin permeability tends to support the hydrodynamic theory. This paper reviews the in vitro evaluation of desensitizing agents, the techniques used to characterize their effects on the prepared dentin surface, and the ability of these agents to reduce permeability through tubule occlusion, and presents recent findings from ongoing research based on the Pashley Dentin Disc model. It can be concluded that the use of this model to determine surface characteristics, and reductions in dentin permeability through tubule narrowing or occlusion, provides a useful screening method for evaluating potential desensitizing agents. Interpreting changes observed in vitro is difficult, and extrapolation to the clinical situation must be tempered with caution.

Combined Effects of Nano-Hydroxyapatite and NaF on Remineralization of Early Caries Lesion

2007 ◽  
Vol 330-332 ◽  
pp. 1347-1350 ◽  
Author(s):  
M.Y. Kim ◽  
H.K. Kwon ◽  
Choong Ho Choi ◽  
B.I. Kim
Keyword(s):  
Statistical Significance ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
P Value ◽  
Distilled Water ◽  
Combined Effects ◽  
Caries Lesion ◽  
Human Enamel ◽  
Early Caries

A previous study reported that many supplements have been added to NaF mouthrinses to improve the remineralization potential. Nano-hydroxyapatite (nano-HA) might also be suitable to this purpose because these nano-size particles can penetrate the enamel pores. Moreover, hydroxyapatite is similar to the inorganic component of teeth and is both bioactive and biocompatible. The aim of this study was to evaluate the combined effects of a nano-HA and fluoride mouthrinse on an early caries lesion in human enamel using an in vitro cycle remineralization and treatment model. Forty-eight human enamel specimens, which had a Vickers Hardness Number (VHN) of 25~45 were artificially demineralized for 48h. There were 8 treatment groups (0%, 1%, 5%, 10% nano-HA in distilled water and the same concentrations of nano-HA in a 0.05% NaF solution). The specimens were incubated in an in vitro remineralization model. After immersing the specimens into the treatment and remineralization solution for 12 hours each, the VHN of each specimen was evaluated for total 24 hours. This step was repeated once again for total 48 hours. The enamel surfaces of all specimens were examined by Confocal Laser Scanning Microscopy (CLSM) and SEM. The statistical significance of the data was identified by one-way ANOVA followed by a Duncan’s studentized range test. A p value < 0.05 was considered significant. The results showed that the degree of remineralization, as revealed by the VHN values, was higher in the NaF groups than in the distilled water groups. The VHNs of the remineralized enamel specimens for 48 hours were higher than after the 24 hours treatment. In addition, the level of remineralization increased with increasing concentration of nano-HA and was more pronounced in the NaF groups than the distilled water groups (p<0.05). The CLSM and SEM images nano-sized particles attached to the enamel in the nano-HA treated groups. Nano-HA might play a synergistic role in remineralization with a fluoride mouthrinse. However, more study will be needed to determine the optimal condition of nano-HA and NaF mouthrinse for human use. In conclusion, nano-HA in a 0.05% NaF mouthrinse can help remineralize an early caries lesion.

scholarly journals Effects of Different Final Irrigating Solutions on Depth of Sealer Penetration into Dentinal Tubules: An in vitro Confocal Laser Microscopic Study

2017 ◽  
Vol 2 (2) ◽  
pp. 69-73
Author(s):  
Madhavi A Shetty
Keyword(s):  
Microscopic Study ◽  
Root Canal ◽  
Maximum Depth ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Dentinal Tubules ◽  
Root Canals ◽  
Group I ◽  
Significant Difference

ABSTRACT Aim To evaluate the maximum depth of sealer penetration into dentinal tubules at the coronal, middle, and apical third of root canals, following the use of different final irrigation solutions. Materials and methods Eighty freshly extracted mandibular premolars were selected for the study. After decoronation, instrumentation of samples was done using Protaper universal rotary file system till F4. During shaping and cleaning of root canal, 5.25% concentration of sodium hypochlorite (NaOCl) was used for irrigation. The samples were then randomly divided into four groups (n = 20) depending on the final irrigating solution used. Group I: 17% aqueous ethylenediaminetetraacetic acid (MA) (aq. EDTA); group II: 10% citric acid (CA); group III: 5% maleic acid; group IV: 5.25% conc. NaOCl. Passive ultrasonic irrigation (PUI) was used to activate each final irrigating solution. The samples were obturated using warm lateral condensation technique with guttapercha coated with AH plus sealer mixed with rhodamine B dye. Confocal laser scanning microscopy (CLSM) examined the sealer penetration depth. Results The Kruskal-Wallis analysis results showed that there was a significant difference in the maximum depth of sealer penetration among all groups in all sections (p < 0.05). The coronal sections of the root canals in each group showed a significantly higher depth of sealer penetration than did the apical and middle sections (p < 0.05). Conclusion A combination of 17% aq. EDTA and PUI used for final irrigation proved to be more effective for sealer penetration into the dentinal tubules. Clinical significance Final irrigation protocol followed is of paramount importance in achieving complete disinfection within the root canal, and also the penetration of sealer serves as an indicator of the extent to which the smear layer was removed. How to cite this article Shetty MA, Hegde V. Effects of Different Final Irrigating Solutions on Depth of Sealer Penetration into Dentinal Tubules: An in vitro Confocal Laser Microscopic Study. J Oper Dent Endod 2017;2(2):69-73.

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