Tooth Whitening Effect of Toothpastes Containing Nano-Hydroxyapatite

2006 ◽  
Vol 309-311 ◽  
pp. 541-544 ◽  
Author(s):  
B.I. Kim ◽  
S. H. Jeong ◽  
S.O. Jang ◽  
Kyoung Nam Kim ◽  
H.K. Kwon ◽  
...  
Keyword(s):  
Artificial Saliva ◽  
In Vitro Study ◽  
Tooth Brushing ◽  
Tooth Whitening ◽  
Whitening Effect ◽  
Before And After ◽  
Group 2 ◽  
Surface Dimension

The aim of this in vitro study was to evaluate the tooth whitening effect of toothpaste containing nano-sized hydroxyapatite (HA). There were 3 types of dentifrices, which had a different level of abrasive components. For group 1, a newly developed toothpaste containing Nano-sized hydroxyapatite (Nano-HA) was used. Commercially available toothpastes were used in groups 2 and 3. Group 2 used toothpastes containing silica and multi phosphate. Group 3 used toothpastes containing abrasives with silica and micro-sized HA. In order to simulate 6-months of tooth brushing, the tooth specimens in all 3 groups were placed on a V8 Cross Brushing Machine (Sabri Co. U.S.A.) and brushed 10,000 times with the toothpaste slurries. The tooth specimens were then soaked in artificial saliva for 24 hours to create conditions similar to those encountered in vivo. The whitening efficacy was assessed before and after tooth brushing using the VITA shade scores of Shadeeye-EX NCC Dental Chroma meter (Shofu Co. Japan). All toothpastes produced significant differences in the mean shade change in the teeth before and after tooth brushing (p<0.05). However, there were no significant differences in the change in the shade between each group (p>0.05). Although the new Nano-HA toothpaste did not have superior whitening effects to the commercially available whitening toothpastes, they had a similar whitening efficacy to commercially available whitening toothpastes. These effects might come from the physical properties of Nano HA, which increase the surface dimension more than the Micro-sized HA and have the potential of remineralization.

scholarly journals Comparing the Effectiveness of Different Dentinal Desensitizing Agents: In Vitro Study

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Mohideen S. Farook ◽  
Okba Mahmoud ◽  
Maysara Adnan Ibrahim ◽  
Marwah Berkathullah
Keyword(s):  
Repeated Measures ◽  
Morphological Changes ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Fluid Filtration ◽  
Formula Group ◽  
Desensitizing Agents ◽  
Edx Analyses ◽  
Group 2

Objectives. To evaluate the in vitro effectiveness of desensitizing agents in reducing dentine permeability. Methods. The efficacy of desensitizing agents in reducing dentine permeability by occluding dentine tubules was evaluated using a fluid filtration device that conducts at 100 cmH2O (1.4 psi) pressure, and SEM/EDX analyses were evaluated and compared. Forty-two dentine discs ( n = 42 ) of 1 ± 0.2   mm width were obtained from caries-free permanent human molars. Thirty dentine discs ( n = 30 ) were randomly divided into 3 groups ( n = 10 ): Group 1: 2.7% wt. monopotassium-monohydrogen oxalate (Mp-Mh oxalate), Group 2: RMGI XT VAR, and Group 3: LIQ SiO2. Dentine permeability was measured following treatment application after 10 minutes, storage in artificial saliva after 10 minutes and 7 days, and citric acid challenge for 3 minutes. Data were analysed with a repeated measures ANOVA test. Dentine discs ( n = 12 ) were used for SEM/EDX analyses to acquire data on morphological changes on dentine surface and its mineral content after different stages of treatment. Results. Desensitizing agents’ application on the demineralized dentine discs exhibited significant reduction of permeability compared to its maximum acid permeability values. Mp-Mh oxalate showed a significant reduction in dentine permeability ( p < 0.05 ) when compared to RMGI XT VAR and LIQ SiO2. On SEM/EDX analysis, all the agents formed mineral precipitates that occluded the dentine tubules. Conclusions. 2.7% wt. monopotassium-monohydrogen oxalate was significantly effective in reducing dentine permeability compared to RMGI XT VAR and LIQ SiO2.

scholarly journals Effects of Carbonated Drinks on Mechanical Properties of Three Types of Thermoplastic Aligner Materials: An In vitro Study

2020 ◽  
Vol 54 (2) ◽  
pp. 115-120
Author(s):  
Leyona Pushpa Femina I. ◽  
Chandrashekar B.S. ◽  
Arun A.V ◽  
Aravind S. Raju ◽  
Ramesh Kumar P.C. ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Artificial Saliva ◽  
Testing Machine ◽  
In Vitro Study ◽  
Control Groups ◽  
Universal Testing ◽  
In Vitro Aging ◽  
Before And After ◽  
Carbonated Drinks

Objectives: The aim was to assess the mechanical properties of the three types of thermoplastic aligner materials before and after in vitro aging with carbonated drinks. Materials and methods: Twelve samples of thermoplastic aligner materials produced by three different manufacturers (Leone S.P.A, Florence, Italy; Duran, SCHEU-dental GmbH, Iserlohn, Germany; Essix ACE, Dentsply Raintree Essix, United States) were selected. Samples were thermoformed and later aged in vitro at a constant temperature in artificial saliva along with carbonated drinks (10 min each day) for 2 weeks. The mechanical properties were characterized using universal testing machine such as instron (MultiTest 10-i) and the results were compared with the control groups (before exposure to carbonated drinks). Results: All the above-mentioned thermoplastic materials tested showed an insignificant ( p > 0.05) decrease in stiffness, yield strength, and elastic modulus after aging. The stiffness of the thermoplastic materials increased with an increase in thickness. The flexure modulus was higher for the thinner materials, whereas it was lower for the thicker materials. Conclusion: Experimental results indicate that the aligner material will remain stable during and following exposure to carbonated drinks, which suggests that the orthodontic force from thermoplastic appliances does not decrease with clinical usage of carbonated drinks.

scholarly journals Red cell aspartate aminotransferase saturation with oral pyridoxine intake

2005 ◽  
Vol 123 (2) ◽  
pp. 54-57 ◽  
Author(s):  
Marilena Oshiro ◽  
Kimiyo Nonoyama ◽  
Raimundo Antônio Gomes Oliveira ◽  
Orlando Cesar de Oliveira Barretto
Keyword(s):  
Aspartate Aminotransferase ◽  
Vitamin B6 ◽  
Pyridoxal Phosphate ◽  
In Vitro Study ◽  
Vitro Study ◽  
Red Cell ◽  
Sideroblastic Anemia ◽  
Before And After

CONTEXT AND OBJECTIVE: The coenzyme of aspartate aminotransferase is pyridoxal phosphate, generated from fresh vegetables containing pyridoxine. Vitamin B6-responsive sideroblastic anemia, myelofibrosis and Peyronie’s syndrome respond to high pyridoxine doses. The objective was to investigate the oral pyridoxine oral dose that would lead to maximized pyridoxal phosphate saturation of red cell aspartate aminotransferase. DESIGN AND SETTING: Controlled trial, in Hematology Division of Instituto Adolfo Lutz. METHODS: Red cell aspartate aminotransferase activity was assayed (before and after) in normal volunteers who were given oral pyridoxine for 15-18 days (30 mg, 100 mg and 200 mg daily). In vitro study of blood from seven normal volunteers was also performed, with before and after assaying of aspartate aminotransferase activity. RESULTS: The in vivo study showed increasing aspartate aminotransferase saturation with increasing pyridoxine doses. 83% saturation was reached with 30 mg daily, 88% with 100 mg, and 93% with 200 mg after 20 days of oral supplementation. The in vitro study did not reach 100% saturation. CONCLUSIONS: Neither in vivo nor in vitro study demonstrated thorough aspartate aminotransferase saturation with its coenzyme pyridoxal phosphate in red cells, from increasing pyridoxine supplementation. However, the 200-mg dose could be employed safely in vitamin B6-responsive sideroblastic anemia, myelofibrosis and Peyronie’s syndrome treatment. Although maximum saturation in circulating red cells is not achieved, erythroblasts and other nucleated and cytoplasmic organelles containing cells certainly will reach thorough saturation, which possibly explains the results obtained in these diseases.

scholarly journals Disorders of Dental Hard Tissues Induced by Radioiodine-131 (I-131) Therapy Used in Differentiated Thyroid Cancer: An In Vitro Study

Biomedicines ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 475
Author(s):  
Alexandru Mester ◽  
Andra Piciu ◽  
Doina Piciu ◽  
Ioan Petean ◽  
Patricia Ondine Lucaciu ◽  
...  
Keyword(s):  
Treatment Time ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Differentiated Thyroid Carcinoma ◽  
Healthy Human ◽  
Compact Structure ◽  
Dimensional Changes ◽  
Dental Hard Tissues

This study aimed to evaluate, in vitro, the effects of I-131 on enamel and dentin in healthy human incisive permanent maxillary teeth. Our in vitro model analogue with the in vivo conditions of differentiated thyroid carcinoma patients treated with I-131, consisted in a solution of I-131 dissolved in artificial saliva. A total of 48 teeth were divided into eight groups (n = 6): control, irradiation groups at 3, 6, 12, 24, 36, 48, and 192 h, respectively. At the end of radiation exposure, radioiodine activity of specimens was assessed. Fine microstructure, nanostructure, surface roughness, and hidroxyapatite (HAP) crystallite diameter were investigated by atomic force microscopy (AFM) to both enamel and dentin structures. There is a constant increase of radioactivity in dental structures at 3, 6, 12, 24 h, due to progressive retention and I-131 migration, with a maximum at 36 h. Enamel showed notable alterations, which was correlated with the increase of the treatment time. A relevant visible distance between the HAP prisms was observed after 24 h. The surface suffered a loss in its compact structure. I-131 acts in the same way on HAP crystallites in dentin as in those in enamel. It was noticed that their morpho-dimensional changes occurred only after 12 h of treatment. Radioiodine-131 determines degradation of enamel and dentin by starting from the alteration of the crystalline network of HAP prisms, transforming them from compact materials into an agglomeration of rocky submicron structures.

THE COMPETITIVE INHIBITION OF AMINE OXIDASE WITH SPECIAL REFERENCE TO THE CARCINOID SYNDROME

1965 ◽  
Vol 43 (7) ◽  
pp. 909-914 ◽  
Author(s):  
J. H. Fellman ◽  
Esther S. Roth
Keyword(s):  
Monoamine Oxidase ◽  
Carcinoid Syndrome ◽  
Competitive Inhibition ◽  
Amine Oxidase ◽  
In Vitro Study ◽  
Urinary Metabolites ◽  
Mitochondrial Monoamine Oxidase ◽  
Before And After

This report deals with an in vitro study of the competitive inhibition of monoamine oxidase by aromatic amines which are substrates for the enzyme. The metabolism of normetanephrine by mitochondrial monoamine oxidase was demonstrated to be competitively inhibited by 5-hydroxytryptamine, and in a similar fashion the oxidation of 5-hydroxytryptamine was shown to be inhibited by normetanephrine. An in vivo demonstration of this effect was contrived as a model of the carcinoid syndrome, and the pattern of the urinary metabolites was examined in rats before and after the intraperitoneal injection of 5-hydroxytryptamine. The data reveal a distortion in pattern of the urinary metabolites of the catecholamines consistent with the idea of an in vivo inhibition of monoamine oxidase by the appearance of a massive amount of 5-hydroxytryptamine. Evidence from a patient afflicted with carcinoid which suggests that this phenomenon operates in this clinical condition and that it may also account for the epinephrine triggering of the flushing syndrome is presented.

Platelet Rheoaggregometry in Native Blood

1979 ◽  
Author(s):  
V. Musumeci ◽  
B. Zappacosta ◽  
R. Marra ◽  
L. Carloni ◽  
B.M. Ricerca
Keyword(s):  
Platelet Aggregation ◽  
Shear Rate ◽  
In Vitro Study ◽  
Plastic Tube ◽  
Before And After ◽  
Platelet Aggregate ◽  
Physiological Approach ◽  
Aggregation Ratio

Platelet aggregation in vivo by shearing forces has been claimed to play the Pathogenesis of thrombosis. A physiological approach to the in vitro study of this phenomenon reguires the use of native blood ana a well defined shear rate. An apparatus was constructed by using a couette viscometer geometry in order to produce in 1 ml of native blood contained in disposable plastic tube a predetermined shear rate, the extent of platelet aggregation was measured by determining in the sample before and after shearing the platelet aggregate ratio according to the method of Wu and Hoak with minor modifications. A large series of unrela eu patients affected by miscellaneous disorders including symptomatic atherosclerosis was investigated by shearing blood for 1 min at a shear rate of 100 sec-1. No correlation was found between platelet aggregate ratios before and after shearing. Platelet aggregation ratio after blood shearing showed in atherosclerotic subjects a more evident trend toward abnormal values.

scholarly journals Effect of Artificial Saliva Contamination on Bond Strength to Pulp Chamber Dentin

2008 ◽  
Vol 02 (02) ◽  
pp. 086-090 ◽  
Author(s):  
Hale Ară ◽  
Nazmiye Dönmez ◽  
Sema Belli
Keyword(s):  
Bond Strength ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Adhesive System ◽  
Control Group ◽  
Pulp Chamber ◽  
Significant Difference ◽  
Group 2 ◽  
Saliva Contamination

ABSTRACTObjectives: The purpose of this in vitro study was to evaluate the effect of artificial saliva contamination on microtensile bond strength to pulp chamber dentin.Methods: Clearfil SE Bond (SEB) (Kuraray, JAPAN) adhesive system and Clearfil Photo Posterior (CPP) (Kuraray, JAPAN) composite resin were used. Twenty extracted caries-free human molar teeth were randomly distributed into four groups. Apart from a control group without contamination (Group 1), primed dentin surfaces were contaminated with artificial saliva (10 s), rinsed, dried, reprimed and bonded (Group 2), coated with adhesive, contaminated with artificial saliva, rinsed, dried, bonding procedures were repeated (Group 3), coated with adhesive, light cured, contaminated with saliva, rinsed, dried, treated with SE primer (SEP) and SEB (Group 4).After 24 hrs, the teeth were prepared for microtensile bond testing and tensile bond strength was measured (1mm/min). The data was calculated as MPa and analyzed using one-way ANOVA and Duncan test (P<.05).Results: The results indicated that Group 2 showed lowest bond strength when compared to the others (P<.05). No statistically significant difference was found between Groups 3 and 4 (P>.05).Conclusions: It was concluded that contamination during priming procedure has a negative effect on bond strength (P<.05). Although contamination of the uncured adhesive was not critical in this study (P>.05) any kind of contamination of the bonding area should, in principle, be avoided. (Eur J Dent 2008;2:86-90)

scholarly journals Effect of CPP-ACP on enamel eroded extrinsically: in vitro study

2018 ◽  
Vol 66 (1) ◽  
pp. 21-28
Author(s):  
Iandara de Lima SCARDINI ◽  
Marcella Kretli Neves DIAS ◽  
Martha Chiabai Cupertino de CASTRO ◽  
Ana Paula Albuquerque GUEDES ◽  
Letícia Monteiro PEIXOTO
Keyword(s):  
Citric Acid ◽  
Tooth Enamel ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Deionized Water ◽  
Statistical Testing ◽  
Immersion Medium ◽  
Significant Difference ◽  
Before And After

ABSTRACT Objective: The aim of this study was to evaluate the remineralization effect of CPP-ACP on tooth enamel that is eroded extrinsically. Methods: Sixty freshly extracted bovine teeth were stored in a solution of thymol (0.1%), cut into enamel blocks (6x6mm), abraded with silicon carbide sandpaper (600, 800 and 1200 grit) and polished with felt. The specimens were randomly divided into 4 groups (n=15), varying the immersion medium , deionized water or citric acid, and the optional use of CPP-ACP. (G1: deionized water; G2: citric acid; G3: deionized water + CPP-ACP; G4: citric acid + CPP-ACP). The samples were subjected to 4 cycles of erosion every day, comprising 5 minutes immersion in one medium and 2 hours of immersion in artificial saliva, for 5 consecutive days. After each erosive cycle, 20 uL of the MI Paste was applied for 5 minutes on one half of the samples and washed with deionized water. Before and after the erosive cycling, the measurements of Vickers hardness and surface roughness were taken. Results: The results were evaluated through statistical testing. The final hardness and roughness values showed no statistically significant difference between G2 and G4. The paste in G4 did not promote an increase in hardness values nor a decrease in roughness values. Conclusion: It was concluded that CPP-ACP was unable to remineralize enamel subjected to extrinsic erosion, being ineffective in preventing erosion of enamel and in the remineralization of the eroded enamel.

Radiolabeled r-Hirudin as a Measure of Thrombin Activity at, or within, the Rabbit Aorta Wall In Vitro and In Vivo

1994 ◽  
Vol 71 (04) ◽  
pp. 499-506 ◽  
Author(s):  
Mark W C Hatton ◽  
Bonnie Ross-Ouellet
Keyword(s):  
Rabbit Aorta ◽  
Balloon Injury ◽  
Recombinant Hirudin ◽  
Aorta Wall ◽  
Thrombin Activity ◽  
Before And After ◽  
The Matrix

SummaryThe behavior of 125I-labeled recombinant hirudin towards the uninjured and de-endothelialized rabbit aorta wall has been studied in vitro and in vivo to determine its usefulness as an indicator of thrombin activity associated with the aorta wall. Thrombin adsorbed to either sulfopropyl-Sephadex or heparin-Sepharose bound >95% of 125I-r-hirudin and the complex remained bound to the matrix. Binding of 125I-r-hirudin to the exposed aorta subendothelium (intima-media) in vitro was increased substantially if the tissue was pre-treated with thrombin; the quantity of l25I-r-hirudin bound to the de-endothelialized intima-media (i.e. balloon-injured in vitro) correlated positively with the quantity of bound 131I-thrombin (p <0.01). Aortas balloon-injured in vivo were measured for thrombin release from, and binding of 125I-r-hirudin to, the de-endothelialized intimal surface in vitro; 125I-r-hirudin binding correlated with the amount of active thrombin released (p <0.001). Uptake of 125I-r-hirudin by the aorta wall in vivo was proportional to the uptake of 131I-fibrinogen (as an indicator of thrombin activity) before and after balloon injury. After 30 min in the circulation, specific 125I-r-hirudin binding to the uninjured and de-endo- thelialized (at 1.5 h after injury) aorta wall was equivalent to 3.4 (± 2.5) and 25.6 (±18.1) fmol of thrombin/cm2 of intima-media, respectively. Possibly, only hirudin-accessible, glycosaminoglycan-bound thrombin is measured in this way.

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