Biomimetic Mechanism of Action of Fluoridated Toothpaste Containing Proprietary REFIX Technology on the Remineralization and Repair of Demineralized Dental Tissues: An in vitro Study

Abstract Objectives This in vitro study aimed to characterize the mineral content and surface and cross-sectional morphology of enamel and dentin tissues treated with a 1450 ppm fluoride-containing toothpaste with REFIX technology. Materials and Methods Bovine enamel blocks (n = 5) were obtained (4 × 4 × 6 mm), demineralized (artificial caries lesion), and treated (pH cycling and brushing with the toothpaste). During the pH cycling, which lasted for 7 days (demineralization and remineralization took 6 and 18 hours, respectively), the enamel was brushed for 5 minutes using an electric toothbrush before being immersed in a remineralizing solution. The dentin blocks were acid-etched for 2 minutes (0.05 M citric acid, pH 1.8) to expose the dentinal tubules (n = 5). Morphological analysis of the dentin was performed immediately and after 7 days of brushing with the dentifrice, and compared with the control group. The specimens were then cross-sectioned. The surface and cross-sectional micromorphology were assessed using scanning electron microscopy (SEM). The elemental analyses (weight%) were determined with an energy-dispersive X-ray spectroscopy (EDS). Results The toothpaste with REFIX technology remineralized and repaired the surface enamel effectively. The elemental analysis also demonstrated that treating the enamel with the toothpaste formed a silicon-enriched mineral layer on the enamel surface. Elemental analysis of the enamel cross-sections showed that the toothpaste induced a mineral change. The results were also consistent in the dentin, where the dentinal tubules were progressively occluded until there was complete occlusion after 7 days. Conclusions We prove the biomimetic mechanism of action of fluoridated toothpaste containing proprietary REFIX technology for obtaining silicon-enriched, remineralized and repaired dental tissues.

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Effect of acidulated phosphate fluoride – gel and foam – on enamel caries-like lesion of primary teeth: an in vitro study

Journal of Research in Dentistry ◽

10.19177/jrd.v1e42013316-327 ◽

2013 ◽

Vol 1 (4) ◽

pp. 316

Author(s):

Karin Faust Souza ◽

Carla Miranda ◽

Izabel Cristina Santos Almeida

Keyword(s):

Primary Teeth ◽

In Vitro Study ◽

Hardness Test ◽

Control Group ◽

Micro Hardness ◽

Cross Sectional ◽

Enamel Caries ◽

Significant Difference ◽

Ph Cycling

The purpose of this study was to evaluate in vitro the effect of APF, gel and foam, for 1 to 4 minutes, on artificial enamel caries-like lesion of primary teeth submitted to the pH cycling. The specimens with medium values of initial superficial enamel micro-hardness between 272 and 331KHN were selected for the formation of the artificial caries lesion. Later, they were randomly divided into 6 groups (n=15): no pH cycling control, cycled control, gel 1min, gel 4min, foam 1min and foam 4min.The no pH cycling control group was maintained in an humid environment, while the application of APF and the pH cycling were accomplished. After, the specimens were sectioned at the center for the enamel cross-sectional micro-hardness test. The values of micro-hardness of the depths from 20 to 180mm were converted into percentile of mineral volume (%Vol) and the area of mineral recovery (∆ZR) was calculated. In spite of there is no statistically significant differences, it was observed through the analysis of the ∆ZR a difference in the values for the groups gel 1min and foam 4min (p>0.05). The evaluation of %Vol indicated a significant difference only at 60mm depth (p=0.005). This study concluded that a single application of APF gel or foam, for 1 or 4 minutes, do not remineralize artificial enamel caries-like lesion of primary teeth

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High-resolution cross-sectional imaging of the gastrointestinal tract using optical coherence tomography: In vitro study

Gastrointestinal Endoscopy ◽

10.1016/s0016-5107(97)80034-x ◽

1997 ◽

Vol 45 (4) ◽

pp. AB33

Author(s):

K. Kobayashi ◽

J.A. Izatt ◽

M.D. Kulkami ◽

H.-S. Wang ◽

M.V. Sivak

Keyword(s):

Optical Coherence Tomography ◽

Gastrointestinal Tract ◽

High Resolution ◽

In Vitro Study ◽

Vitro Study ◽

Optical Coherence ◽

Cross Sectional ◽

Cross Sectional Imaging ◽

Sectional Imaging

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Effect of topical fluoride on microshear bond strength of primary enamel to composite, microhardness of enamel and its surface morphology: An in vitro study

Journal of Dental Research Dental Clinics Dental Prospects ◽

10.15171/joddd.2019.046 ◽

2019 ◽

Vol 13 (4) ◽

pp. 305-310

Author(s):

Mina Biria ◽

Sajedeh Namaei Ghasemi ◽

Seyedeh Mahsa Sheikh-Al-Eslamian ◽

Narges Panahandeh

Keyword(s):

Bond Strength ◽

Artificial Saliva ◽

Morphological Characteristics ◽

In Vitro Study ◽

Vitro Study ◽

Control Group ◽

Modes Of Failure ◽

Group 3 ◽

Microshear Bond Strength

Background. This in vitro study aimed to evaluate the microshear bond strength (μSBS), microhardness and morphological characteristics of primary enamel after treating with sodium fluoride (NaF) and acidulated phosphate fluoride (APF). Methods. Forty-eight primary canines were cut into mesial and distal sections and assigned to five groups randomly: group 1 (immersed in saliva as a control), group 2 (treated with NAF and immersed in saliva for 30 minutes), group 3 (treated with APF and immersed in saliva for 30 minutes), group 4 (treated with NAF and immersed in saliva for 10 days), and group 5 (treated with APF and immersed in saliva for 10 days). Composite resin (Filtek Z250) was bonded on the specimens (n=15) for measuring the μSBS. After storage in 37°C artificial saliva for 24 hours, µSBS and Vickers hardness tests (10 readings) were performed. The data were analyzed using one-way ANOVA and Kolmogorov-Smirnov, Levene’s and Tukey HSD tests (P<0.05). Morphological analysis of enamel and modes of failure were carried out under a scanning electron microscope (SEM) on two remaining specimens. Results. Significant differences in μSBS were only noted between groups 2 and 4 (P=0.024). Group 3 showed a significant decrease in hardness after storage in artificial saliva (P<0.001), with a significantly lower hardness than the other groups (P<0.001). The SEM observations showed irregular particles in groups 3 and 5; uniform, smooth and thin coats were seen in groups 2 and 4. Conclusion. Fluoride therapy with NaF and APF gels prior to restorative treatments had no adverse effects on the microshear bond strength.

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A Possible Mechanism of Action of 17α-Hydroxyprogesterone Caproate: Enhanced IL-10 Production

American Journal of Perinatology ◽

10.1055/s-0041-1739354 ◽

2021 ◽

Author(s):

Christina J. Megli ◽

Alisse Hauspurg ◽

Raman Venkataramanan ◽

Steve N. Caritis

Keyword(s):

Mechanism Of Action ◽

Cytokine Production ◽

Plasma Concentrations ◽

In Vitro Study ◽

Vitro Study ◽

Clinical Samples ◽

Omega 3 ◽

Tnf Α ◽

Hydroxyprogesterone Caproate

Objective The rate of recurrent spontaneous preterm birth (PTB) was reduced by 33% in the Maternal-Fetal Medicine Unit (MFMU) Network trial of 17α-hydroxyprogesterone caproate (17-OHPC), but the mechanism of action, 17 years later, remains elusive. The robustness of the interleukin-10 (IL-10) response to lipopolysaccharide (LPS) stimulation of leukocytes in pregnant women with a prior PTB correlates with gestational age at delivery. This study sought to determine if there is a relationship between the concentration of 17-OHPC and response to LPS stimulation. Study Design We performed a secondary analysis of data from the Omega-3 MFMU trial which evaluated the effectiveness of omega-3 fatty acid supplementation in reducing recurrent PTB. We utilized previously characterized data from a subanalyses of the Omega-3 trial of IL-10 and tumor necrosis factor alpha (TNF-α) levels from peripheral blood mononuclear cells stimulated with LPS. Blood was obtained from enrolled women at 16 to 22 weeks' gestation (baseline) and 25 to 28 weeks' gestation (posttreatment). All women received 17-OHPC and plasma 17-OHPC concentrations were measured at 25 to 28 weeks' gestation. We analyzed these data to determine if there was a relationship between 17-OHPC concentration and cytokine production. We then performed an in vitro study to determine if 17-OHPC could directly alter cytokine production by THP-1-derived macrophages. Results In the clinical samples, we found that 17-OHPC plasma concentrations were correlated with the quantity of the LPS-stimulated production of IL-10. TNF-α production after LPS stimulation was unrelated to 17-OHPC concentration. In the in vitro study, we demonstrate a 17-OHPC concentration dependent increase in IL-10 production. Conclusion In women receiving 17-OHPC for PTB prevention, we demonstrate a relationship between plasma 17-OHPC and LPS-stimulated IL-10 production by circulating leukocytes. We also demonstrate that, in vitro, 17-OHPC treatment affects IL-10 production by LPS-stimulated macrophages. Collectively, these findings support an immunomodulatory mechanism of action of 17-OHPC in the prevention of recurrent PTB. Key Points

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

Journal of Dental Lasers ◽

10.4103/0976-2868.106653 ◽

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

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In Vitro Study on the Effect of a New Bioactive Desensitizer on Dentin Tubule Sealing and Bonding

Journal of Functional Biomaterials ◽

10.3390/jfb11020038 ◽

2020 ◽

Vol 11 (2) ◽

pp. 38

Author(s):

Minh N. Luong ◽

Laurie Huang ◽

Daniel C. N. Chan ◽

Alireza Sadr

Keyword(s):

Bond Strength ◽

In Vitro Study ◽

Vitro Study ◽

Acid Pretreatment ◽

Universal Adhesive ◽

Cross Sectional ◽

Before And After ◽

Human Dentin ◽

Microshear Bond Strength

Bioactive mineral-based dentin desensitizers that can quickly and effectively seal dentinal tubules and promote dentin mineralization are desired. This in vitro study evaluated a novel nanohydroxyapatite-based desensitizer, Predicta (PBD, Parkell), and its effect on bond strength of dental adhesives. Human dentin discs (2-mm thick) were subjected to 0.5 M EDTA to remove the smear layer and expose tubules, treated with PBD, and processed for surface and cross-sectional SEM examination before and after immersion in simulated body fluid (SBF) for four weeks (ISO 23317-2014). The effects of two dental desensitizers on the microshear bond strength of a universal adhesive and a two-step self-etch system were compared. SEM showed coverage and penetration of nanoparticles in wide tubules on the PBD-treated dentin at the baseline. After four weeks in SBF, untreated dentin showed amorphous mineral deposits while PBD-treated dentin disclosed a highly mineralized structure integrated with dentin. Desensitizers significantly reduced microshear bond strength test (MSBS) of adhesives by 15–20% on average, depending on the bonding protocol. In conclusion, PBD demonstrated effective immediate tubules sealing capability and promoted mineral crystal growth over dentin and into the tubules during SBF-storage. For bonding to desensitizer-treated dentin, a two-step self-etching adhesive or universal bond with phosphoric acid pretreatment are recommended.

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Effects of CO2laser irradiation on matrix-rich biofilm development formation–an in vitro study

PeerJ ◽

10.7717/peerj.2458 ◽

2016 ◽

Vol 4 ◽

pp. e2458 ◽

Cited By ~ 6

Author(s):

Bruna Raquel Zancopé ◽

Vanessa B. Dainezi ◽

Marinês Nobre-dos-Santos ◽

Sillas Duarte ◽

Vanessa Pardi ◽

...

Keyword(s):

Contact Angle ◽

Biofilm Formation ◽

Dental Enamel ◽

In Vitro Study ◽

Dry Weight ◽

Vitro Study ◽

Enamel Surface ◽

Control Group ◽

Biofilm Development

BackgroundA carbon dioxide (CO2) laser has been used to morphologically and chemically modify the dental enamel surface as well as to make it more resistant to demineralization. Despite a variety of experiments demonstrating the inhibitory effect of a CO2laser in reduce enamel demineralization, little is known about the effect of surface irradiated on bacterial growth. Thus, this in vitro study was preformed to evaluate the biofilm formation on enamel previously irradiated with a CO2laser (λ = 10.6 µM).MethodsFor this in vitro study, 96 specimens of bovine enamel were employed, which were divided into two groups (n = 48): 1) Control-non-irradiated surface and 2) Irradiated enamel surface. Biofilms were grown on the enamel specimens by one, three and five days under intermittent cariogenic condition in the irradiated and non-irradiated surface. In each assessment time, the biofilm were evaluated by dry weigh, counting the number of viable colonies and, in fifth day, were evaluated by polysaccharides analysis, quantitative real time Polymerase Chain Reaction (PCR) as well as by contact angle. In addition, the morphology of biofilms was characterized by fluorescence microscopy and field emission scanning electron microscopy (FESEM). Initially, the assumptions of equal variances and normal distribution of errors were conferred and the results are analyzed statistically by t-test and Mann Whitney test.ResultsThe mean of log CFU/mL obtained for the one-day biofilm evaluation showed that there is statistical difference between the experimental groups. When biofilms were exposed to the CO2laser, CFU/mL and CFU/dry weight in three day was reduced significantly compared with control group. The difference in the genes expression (Glucosyltransferases (gtfB) and Glucan-binding protein (gbpB)) and polysaccharides was not statically significant. Contact angle was increased relative to control when the surface was irradiated with the CO2laser. Similar morphology was also visible with both treatments; however, the irradiated group revealed evidence of melting and fusion in the specimens.ConclusionIn conclusion, CO2laser irradiation modifies the energy surface and disrupts the initial biofilm formation.

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