Effect of Perfusion with Water on Demineralization of Human Dentin in vitro

2002 ◽  
Vol 81 (11) ◽  
pp. 733-737 ◽  
Author(s):  
A.R. Özok ◽  
M.-K. Wu ◽  
J.M. ten Cate ◽  
P.R. Wesselink
Keyword(s):  
Fluid Flow ◽  
Fluid Transport ◽  
Transport Model ◽  
Human Tooth ◽  
Lesion Depth ◽  
Human Dentin ◽  
Dentinal Fluid Flow ◽  
Dentin Thickness ◽  
Mineral Loss

Dentinal fluid rarely features in caries studies of dentin. The mutual effects of in vitro perfusion and dentin demineralization were investigated. The correlation between the remaining dentin thickness and demineralization was also analyzed. Buccal cervical dentin windows in human tooth segments were demineralized either with or without perfusion with water at 3.14 kPa. Transverse microradiography revealed that dentin perfusion reduced the amount of mineral loss from the lesions by 22vol%; the reduction in lesion depth was 8%. Perfusion rate, which was measured throughout the demineralization process by means of a fluid transport model, did not change significantly. Lesions formed closer to the pulp exhibited increased mineral loss and lesion depth. In conclusion, dentinal fluid flow offers some protection against demineralization. For a better approximation of clinical reality, therefore, in vitro studies on dentinal caries should consider the effect of dentinal fluid flow.

Effect of Dentinal Fluid Composition on Dentin Demineralization in vitro

2004 ◽  
Vol 83 (11) ◽  
pp. 849-853 ◽  
Author(s):  
A.R. Özok ◽  
M.-K. Wu ◽  
J.M. Ten Cate ◽  
P.R. Wesselink
Keyword(s):  
Flow Rate ◽  
Fluid Transport ◽  
Important Determinant ◽  
Fluid Composition ◽  
Perfusion Rate ◽  
Lesion Formation ◽  
Lesion Depth ◽  
Set Up ◽  
Mineral Loss

Dentin demineralization is reduced by perfusion with water. We hypothesized that a simulated dentinal fluid (SDF) that contains albumin, in addition to electrolytes, would be more effective in reducing dentin demineralization than water alone, and this effect would increase with increasing flow rate of SDF. Perfusion rate in tooth segments that carried buccal cervical dentin windows was measured in a fluid transport set-up. These windows were then demineralized under perfusion with water, or SDF at 1.47 kPa for 31 days. We analyzed integrated mineral loss and lesion depth with the use of transverse microradiography (TMR), which revealed that 38% more mineral dissolved from dentin lesions perfused with water than from those perfused with SDF. The former were also 18% deeper. Flow rate of dentinal fluid showed no correlation with demineralization. We concluded that composition of dentinal fluid is an important determinant of the rate of lesion formation and progression in dentin.

In Vitro Study to Compare the Coronal Microleakage of Tempit UltraF, Tempit, IRM, and Cavit by Using the Fluid Transport Model

2008 ◽  
Vol 34 (4) ◽  
pp. 442-444 ◽  
Author(s):  
Susan O. Koagel ◽  
Pete Mines ◽  
Michael Apicella ◽  
Mark Sweet
Keyword(s):  
Fluid Transport ◽  
Transport Model ◽  
In Vitro Study ◽  
Vitro Study

Minimizing Dentinal Fluid Flow Associated with Gap Formation

2006 ◽  
Vol 85 (11) ◽  
pp. 1027-1031 ◽  
Author(s):  
D.N. Ratih ◽  
J.E.A. Palamara ◽  
H.H. Messer
Keyword(s):  
Fluid Flow ◽  
Resin Composite ◽  
Glass Ionomer Cement ◽  
Glass Ionomer ◽  
Gap Formation ◽  
Bonding Agents ◽  
Dentinal Fluid Flow ◽  
Light Curing ◽  
Ionomer Cement

The relationship between gap formation and outward fluid flow and procedures to minimize both phenomena were investigated in extracted human premolars restored in vitro with MOD composite restorations. We hypothesized that either glass-ionomer cement (GIC) liners or low-shrinkage composite could reduce fluid flow related to gap formation. Two groups restored with bonding agents with either high- or low-shrinkage resin composites, and 2 groups restored by either conventional or light-cured GIC liner plus resin composite were compared (8 teeth/group). Fluid flow was measured with an automated apparatus. Baseline fluid flow was low and unchanged after bonding, but increased sharply (though transiently) after teeth were lined with GIC. Outward flow was significantly greater with conventional than with light-cured GIC. Inward fluid flow occurred during light-curing, followed by extensive, prolonged outward flow after curing. Low-shrinkage composite or GIC liners reduced gap formation and limited outward fluid flow. GIC liners promoted outward fluid flow during their setting reactions. Abbreviations: GIC, glass-ionomer cement; CEJ, cemento-enamel junction; MOD, mesio-occluso-distal; SEM, scanning electron microscopy.

In Vitro Progression of Artificial White Spot Lesions Sealed With an Infiltrant Resin

2014 ◽  
Vol 39 (5) ◽  
pp. 481-488 ◽  
Author(s):  
R Gelani ◽  
AF Zandona ◽  
F Lippert ◽  
MM Kamocka ◽  
G Eckert
Keyword(s):  
Control Group ◽  
White Spot Lesions ◽  
Lesion Depth ◽  
Group 4 ◽  
Group 5 ◽  
Infiltrant Resin ◽  
Saliva Contamination ◽  
Mineral Loss ◽  
Group 1

SUMMARY This study assessed the ability of an infiltrant resin (Icon, DMG Chemisch-Pharmazeutische Fabrik GmbH, Hamburg, Germany) to prevent artificial lesion progression in vitro when used to impregnate white spot lesions and also assessed the effect of saliva contamination on resin infiltration. Enamel specimens (n=252) were prepared and covered with nail varnish, leaving a window of sound enamel. After demineralization (pH 5.0; four weeks), specimens were divided into six groups (n=42 per group): group 1, 2% fluoride gel (positive control); group 2, resin infiltrant; group 3, resin infiltrant + fluoride gel; group 4, no treatment (negative control); group 5, resin infiltrant application after saliva contamination; and group 6, resin infiltrant + fluoride gel after saliva contamination. Specimens from each group were cut perpendicular to the surface, and one-half of each specimen was exposed to a demineralizing solution for another four weeks. The other half was set aside as a record of initial lesion depth and was used later in the determination of lesion progression. Lesion progression and infiltrant penetration were measured using confocal laser scanning microscopy (CLSM) and transverse microradiography (TMR). For lesion depth, based on CLSM, groups 2 and 3 showed the least changes when submitted to demineralization challenge, followed by group 1, then groups 5 and 6, and finally group 4. There were no significant differences between groups 2 and 3 or groups 5 and 6 in their ability to inhibit further lesion progression (p<0.05). Based on TMR, groups 2 and 3 also showed the fewest changes when submitted to demineralization challenge, followed by group 5, then groups 1 and 6, and finally group 4. In terms of mineral loss as measured by TMR, all groups that contained fluoride (groups 1, 3, and 6) show less percentage change in mineral loss than the groups that did not contain fluoride (groups 2, 4, and 5). It can be concluded that infiltrant penetration into early enamel lesions inhibited further demineralization in vitro, especially in the presence of fluoride. Saliva contamination decreased the ability of the infiltrant to prevent further demineralization, but the presence of fluoride seemed to counteract this effect.

Permeability Characteristics of Human Dentin and a Porous Ceramic

2011 ◽  
Vol 492 ◽  
pp. 501-504 ◽  
Author(s):  
Xin Yi Zhao ◽  
Ya Ping Li ◽  
Shi Bao Li
Keyword(s):  
Bovine Serum ◽  
Transport Model ◽  
Porous Ceramic ◽  
Third Molar ◽  
Hydraulic Conductance ◽  
Cytotoxicity Test ◽  
Perfusion Fluid ◽  
Human Dentin ◽  
The Mean

Objectives: To compare the permeability of human dentin and a porous ceramic with two different compositions of perfusion fluid, in vitro. Methods: Dentin discs were cut from extracted third molar at a level close to the pulp chamber and ceramic discs were cut from a porous ceramic block. The convective permeability of the discs was measured in a fluid transport model using de-ionised water or 1:3 diluted bovine serum and the hydraulic conductance was determined. Results: In the negative controls, no flow was detected. The hydraulic conductance values for the dentin discs and the ceramic discs when water was used as the perfusion fluid were 0.069±0.023and 0.047±0.019ml min-1 cm-2 cm H2O-1, respectively. When the discs were perfused with the diluted bovine serum the mean (standard error of the mean) hydraulic conductance values for the dentin and the ceramic discs were 0.036±0.016 and 0.012±0.0055 ml min-1 cm-2 cm H2O-1, respectively. Conclusion: Basing on the modern technique it is possible to fabricate discs of hydroxylapatite ceramic to act as substitutes for dentin barriers in cytotoxicity test.

Effect of Lesion Baseline Severity and Mineral Distribution on Remineralization and Progression of Human and Bovine Dentin Caries Lesions

2015 ◽  
Vol 49 (5) ◽  
pp. 467-476 ◽  
Author(s):  
Frank Lippert ◽  
David Churchley ◽  
Richard J. Lynch
Keyword(s):  
Root Caries ◽  
Mineral Distribution ◽  
Lesion Depth ◽  
Baseline Severity ◽  
Dentin Caries ◽  
Lesion Type ◽  
Human Dentin ◽  
Root Dentin ◽  
Caries Lesions ◽  
Mineral Loss

The aims of this laboratory study were to compare the effects of lesion baseline severity, mineral distribution and substrate on remineralization and progression of caries lesions created in root dentin. Lesions were formed in dentin specimens prepared from human and bovine dentin using three protocols, each utilizing three demineralization periods to create lesions of different mineral distributions (subsurface, moderate softening, extreme softening) and severity within each lesion type. Lesions were then either remineralized or demineralized further and analyzed using transverse microradiography. At lesion baseline, no differences were found between human and bovine dentin for integrated mineral loss (ΔZ). Differences in mineral distribution between lesion types were apparent. Human dentin lesions were more prone to secondary demineralization (ΔΔZ) than bovine dentin lesions, although there were no differences in ΔL. Likewise, smaller lesions were more susceptible to secondary demineralization than larger ones. Subsurface lesions were more acid-resistant than moderately and extremely softened lesions. After remineralization, differences between human and bovine dentin lesions were not apparent for ΔΔZ although bovine dentin lesions showed greater reduction in lesion depth L. For lesion types, responsiveness to remineralization (ΔΔZ) was in the order extremely softened > moderately softened > subsurface. More demineralized lesions exhibited greater remineralization than shallower ones. In summary, some differences exist between human and bovine dentin and their relative responsiveness to de- and remineralization. These differences, however, were overshadowed by the effects of lesion baseline mineral distribution and severity. Thus, bovine dentin appears to be a suitable substitute for human dentin in mechanistic root caries studies.

scholarly journals Photoinhibition of Streptococcus mutans Biofilm-Induced Lesions in Human Dentin by Violet-Blue Light

2019 ◽  
Vol 7 (4) ◽  
pp. 113 ◽  
Author(s):  
Grace Gomez Felix Gomez ◽  
Frank Lippert ◽  
Masatoshi Ando ◽  
Andrea F. Zandona ◽  
George J. Eckert ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Blue Light ◽  
In Vitro Study ◽  
Microtiter Plate ◽  
Significance Level ◽  
Supernatant Liquid ◽  
Colony Forming Units ◽  
Human Dentin ◽  
Mineral Loss

This in vitro study determined the effectiveness of violet-blue light on Streptococcus mutans (UA159) biofilm induced dentinal lesions. Biofilm was formed on human dentin specimens in a 96-well microtiter plate and incubated for 13 h in the presence of tryptic soy broth (TSB) or TSB supplemented with 1% sucrose (TSBS). Violet-blue light (405 nm) from quantitative light-induced fluorescence (QLFTM) was used to irradiate the biofilm. Supernatant liquid was removed, and the biofilm was irradiated continuously with QLF for 5 min twice daily with an interval of 6 h for 5 d, except with one treatment on the final day. Colony forming units (CFU) of the treated biofilm, changes in fluorescence (∆F; QLF-Digital BiluminatorTM), lesion depth (L), and integrated mineral loss (∆Z; both transverse microradiography) were quantified at the end of the fifth day. Statistical analysis used analysis of variance (ANOVA), testing at a 5% significance level. In the violet-blue light irradiated groups, there was a significant reduction (p < 0.05) of bacterial viability (CFU) of S. mutans with TSB and TSBS. Violet-blue light irradiation resulted in the reduction of ∆F and L of the dentinal surface with TSBS. These results indicate that violet-blue light has the capacity to reduce S. mutans cell numbers.

Pulpal Remineralisation of Artificial Residual Caries Lesions in vitro

2015 ◽  
Vol 49 (6) ◽  
pp. 591-594 ◽  
Author(s):  
Falk Schwendicke ◽  
Allam Al-Abdi ◽  
Hendrik Meyer-Lückel ◽  
Sebastian Paris
Keyword(s):  
Fluid Composition ◽  
Human Dentin ◽  
Residual Caries ◽  
Caries Lesions ◽  
Mineral Loss

We assessed pulpal remineralisation of caries lesions in vitro. On the coronal aspect of human dentin discs (n = 70), artificial lesions [mineral loss ΔZ (mean ± SD) = 3,060 ± 604 vol% × µm] were induced, covered and pulpal surfaces exposed to pulpal fluid, remineralisation medium or water at pressures of 0, 1.47 or 2.94 kPa for 3 months. Mineral loss differences were assessed using transversal microradiography. No significant mineral gain occurred at 0 kPa and in samples exposed to water. At 1.47 and 2.94 kPa, pulpal and remineralisation fluid induced significant mineral gain [ΔΔZ = 1,317 (25th/75th percentiles: 735/1,541) vol% × µm; p < 0.001]. Pressure and fluid composition determined pulpal remineralisation in vitro.

Factors Affecting the Wear Behavior of Monolithic Zirconia and the Antagonists: Literature Review

2020 ◽  
Vol 2 (1) ◽  
pp. 4-11
Author(s):  
Marcia Borba ◽  
Paula Benetti ◽  
Giordana P. Furini ◽  
Kátia R. Weber ◽  
Tábata M. da Silva
Keyword(s):  
Literature Review ◽  
Glass Ceramic ◽  
Wear Behavior ◽  
Glass Ceramics ◽  
Surface Treatments ◽  
Human Tooth ◽  
Initial Surface ◽  
Monolithic Zirconia ◽  
Feldspathic Porcelain

Background: The use of zirconia-based ceramics to produce monolithic restorations has increased due to improvements in the optical properties of the materials. Traditionally, zirconiabased ceramics were veneered with porcelain or glass-ceramic and were not directly exposed to the oral environment. Therefore, there are several doubts regarding the wear of the monolithic zirconia restoration and their antagonists. Additionally, different surface treatments are recommended to promote a smooth surface, including glaze and several polishing protocols. To support the correct clinical application, it is important to understand the advantages and limitations of each surface treatment. Objective: The aim of this short literature review is to investigate the factors that may affect the wear of monolithic zirconia restorations in service and their antagonists. Methods: Pubmed/Medline database was accessed to review the literature from a 10-year period using the keywords: zirconia, monolithic, prosthesis, wear. Both clinical and in vitro studies were included in the review. Results: Studies investigated the effect of several surface treatments, including grinding with diamond- burs, polishing and glazing, on the surface roughness, phase transformation and wear capacity of monolithic zirconia. The wear behavior of monolithic zirconia was frequently compared to the wear behavior of other ceramics, such as feldspathic porcelain, lithium disilicate-based glassceramic and leucite-reinforced glass-ceramic. Human tooth, ceramics and resin composites were used as antagonist in the investigations. Only short-term clinical studies are available (up to 2 years). Conclusion: Literature findings suggest that zirconia monolithic restorations are wear resistant and unlikely to cause excessive wear to the antagonist, especially when compared to feldspathic porcelain and glass-ceramics. Monolithic zirconia should be polished rather than glazed. Yet, none of the polishing systems studied was able to completely restore the initial surface conditions of zirconia after being adjusted with burs. More clinical evidence of the antagonist tooth wear potential of monolithic zirconia is needed.

scholarly journals O23: CHARACTERISING PATIENT-DERIVED COLORECTAL CANCER TISSUE-ORIGINATED ORGANOIDAL SPHEROIDS FOR HIGH-THROUGHPUT MICROFLUIDIC APPLICATIONS

2021 ◽  
Vol 108 (Supplement_1) ◽  
Author(s):  
MI Khot ◽  
M Levenstein ◽  
R Coppo ◽  
J Kondo ◽  
M Inoue ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Fluid Flow ◽  
High Throughput ◽  
Microfluidic Devices ◽  
In Vitro Models ◽  
Fluorescent Imaging ◽  
Cancer Tissue ◽  
Cell Models

Abstract Introduction Three-dimensional (3D) cell models have gained reputation as better representations of in vivo cancers as compared to monolayered cultures. Recently, patient tumour tissue-derived organoids have advanced the scope of complex in vitro models, by allowing patient-specific tumour cultures to be generated for developing new medicines and patient-tailored treatments. Integrating 3D cell and organoid culturing into microfluidics, can streamline traditional protocols and allow complex and precise high-throughput experiments to be performed with ease. Method Patient-derived colorectal cancer tissue-originated organoidal spheroids (CTOS) cultures were acquired from Kyoto University, Japan. CTOS were cultured in Matrigel and stem-cell media. CTOS were treated with 5-fluorouracil and cytotoxicity evaluated via fluorescent imaging and ATP assay. CTOS were embedded, sectioned and subjected to H&E staining and immunofluorescence for ABCG2 and Ki67 proteins. HT29 colorectal cancer spheroids were produced on microfluidic devices using cell suspensions and subjected to 5-fluorouracil treatment via fluid flow. Cytotoxicity was evaluated through fluorescent imaging and LDH assay. Result 5-fluorouracil dose-dependent reduction in cell viability was observed in CTOS cultures (p&lt;0.01). Colorectal CTOS cultures retained the histology, tissue architecture and protein expression of the colonic epithelial structure. Uniform 3D HT29 spheroids were generated in the microfluidic devices. 5-fluorouracil treatment of spheroids and cytotoxic analysis was achieved conveniently through fluid flow. Conclusion Patient-derived CTOS are better complex models of in vivo cancers than 3D cell models and can improve the clinical translation of novel treatments. Microfluidics can streamline high-throughput screening and reduce the practical difficulties of conventional organoid and 3D cell culturing. Take-home message Organoids are the most advanced in vitro models of clinical cancers. Microfluidics can streamline and improve traditional laboratory experiments.

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