scholarly journals Cyclodextrin and TiF4 Nanocomplex on Enamel Demineralization

2020 ◽  
Vol 31 (4) ◽  
pp. 423-430
Author(s):  
Thiago Vieira ◽  
Adílis K. Alexandria ◽  
Lilian H. Amaral ◽  
Aline de A. Neves ◽  
Ricardo T. Lopes ◽  
...  
Keyword(s):  
Ct Scanning ◽  
Lower Percentage ◽  
Micro Ct ◽  
Surface Microhardness ◽  
Cross Sectional ◽  
Titanium Tetrafluoride ◽  
X Ray ◽  
Bovine Enamel ◽  
Mineral Loss

Abstract The aim of this study was to assess the effect of a newly developed nanocomplex formed of hydroxypropyl-b-cyclodextrin and 1% titanium tetrafluoride (TiF4) after distinct complexation periods (12/72 h) on demineralization of bovine enamel in vitro. Enamel blocks (n=60) were allocated in different groups: Mili-Q water, hydroxypropyl-b-cyclodextrin, 1% TiF4, hydroxypropyl-b-cyclodextrin + 1% TiF4 after 12 h of complexation and hydroxypropyl-b-cyclodextrin + 1% TiF4 after 72 h of complexation. The samples were evaluated by surface microhardness, cross-sectional microhardness and micro-CT. Scanning electron microscopy and energy dispersive X-ray spectrometry (SEM/EDX) were also obtained. Hydroxypropyl-b-cyclodextrin + 1% TiF4 after 12 h complexation resulted in lower percentage of surface microhardness loss compared to Mili-Q water, hydroxypropyl-b-cyclodextrin, 1% TiF4 and hydroxypropyl-b-cyclodextrin + 1% TiF4 after 72 h of complexation group, with a large effect size (from 1.307 to 2.943) and high power (84.9 to 99%). All groups resulted in similar integrated mineral loss (ΔZ) obtained by both internal microhardness and micro-CT techniques. Enamel treated with TiF4 and TiF4 + hydroxypropyl-b-cyclodextrin groups showed a TiO2 glaze-layer, while EDX evaluation identified Ti. The solution containing the inclusion complex of hydroxypropyl-b-cyclodextrin + TiF4 with 12 h of complexation period demonstrated a significant ability to reduce surface demineralization of sound enamel under an artificial cariogenic challenge.

Effect of Heavy Metals Contamination from Cigarette Smoke on Sound and Caries-Like Enamel

2018 ◽  
Vol 24 (6) ◽  
pp. 762-767 ◽  
Author(s):  
Jéssica D. Theobaldo ◽  
Waldemir F. Vieira-Junior ◽  
Anderson Catelan ◽  
Maria do Carmo A. Mainardi ◽  
Orlando A. Ysnaga ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Cigarette Smoke ◽  
Surface Microhardness ◽  
Treatment Control ◽  
Cross Sectional ◽  
X Ray ◽  
Heavy Metals Contamination ◽  
Heavy Metal Deposition ◽  
Ph Cycling

AbstractIn this study, we sought to evaluate the influence of cigarette smoke and pH cycling on the chemical composition and surface/cross-sectional enamel microhardness. A total of 40 dental blocks obtained from bovine incisors were divided into four groups (n=10): no treatment (control); exposure to cigarette smoke (CS); exposure to pH cycling (PC); and exposure to cigarette smoke and pH cycling (CS-PC). The samples were analyzed by synchrotron radiation micro X-ray fluorescence, bench mode X-ray fluorescence, as well as surface microhardness (SMH) and cross-sectional microhardness (CSMH) testing. The SMH results were submitted to analysis of variance (ANOVA) and Tukey’s test. The CSMH results were evaluated using split-plot ANOVA and Tukey’s test. A high amount of Cd and Pb and traces of Ni and As were observed in enamel and dentin after exposure to cigarette smoke (CS and CS-PC). The SMH and CSMH of CS were statistically higher when compared with the control. The PC and CS-PC showed lower SMH and CSMH. We conclude that exposure to cigarette smoke promoted heavy metal deposition in enamel/dentin. In addition, it increased the enamel microhardness but did not promote a protective effect on the in vitro development of caries. The clinical significance of this work is that there is significant bioaccumulation of heavy metals from cigarette smoke on the surface and in the enamel and dentin.

scholarly journals A Preliminary Report on the Use of Bench-Top X-Ray Micro-Computerised Tomography to Study the Malpighian Tubules of the Overwintering Seven Spotted LadybirdCoccinella septempunctataL. (Coleoptera: Coccinellidae)

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Duncan Bell ◽  
Lewis Woolnough ◽  
David Mortimore ◽  
Nick Corps ◽  
Diana M. Hudson ◽  
...  
Keyword(s):  
Coccinella Septempunctata ◽  
Ct Scanning ◽  
Small Sample ◽  
Malpighian Tubules ◽  
Micro Ct ◽  
Computerised Tomography ◽  
X Ray ◽  
High Concentrations ◽  
Very High ◽  
Metallic Pollutants

The application of micro-CT scanning techniques on a small sample of “Seven-spot ladybirds”Coccinella septempunctata,collected in December 2009, identified an accumulation of material with a very high, relative X-ray attenuation value in the malpighian tubules of most but not all of the individuals sampled. The passage of metals such as cadmium in soil through a food chain to finally accumulate in high concentrations in ladybirds and lacewings has been previously reported. The identification of the dense material found in our sample of ladybirds, its origin, and the process by which it accumulates in, and is processed by, the malpighian tubules is the challenge ahead. The authors speculate that a straightforward means of monitoring levels of metallic pollutants in the environment might emerge.

Effect of Whole Saliva Components on Enamel Demineralization In Vitro

1993 ◽  
Vol 4 (3) ◽  
pp. 357-362 ◽  
Author(s):  
J.D.B. Featherstone ◽  
J.M. Behrman ◽  
J.E. Bell
Keyword(s):  
Dental Enamel ◽  
Acid Resistance ◽  
Human Teeth ◽  
Cross Sectional ◽  
Basic Proteins ◽  
Enamel Demineralization ◽  
Whole Saliva ◽  
Flow Through ◽  
Mineral Loss

The aim of the present study was to use an in vitro enamel demineralization model (1) to confirm that whole saliva pretreatment conferred acid resistance to dental enamel and (2) to determine whether this phenomenon was attributable to specific salivary proteins, minerals, lipids, or some combination of these. Crowns of human teeth, each with one exposed window, were prepared in groups of ten. They were each pretreated by immersion individually in 4 ml of either (1) clarified whole saliva for 18, 72, or 168 h, (2) dialyzed saliva (3500 MWCO membrane), (3) the "flow-through" fraction from a DEAE separation of whole saliva (neutral and basic proteins), (4) the "eluted" fraction of a DEAE separation of whole saliva (anionic proteins), or (5) a combination of salivary lipids and the DEAE "flow-through" fraction of whole saliva (neutral and basic proteins). Control groups were group 6 with no pretreatment, group 7 pretreated for 168 h in a borate buffer (5 mmol/1), and group 8 pretreated in a mineral solution containing calcium (0.7 mmol/1) and phosphate (2.6 mmol/1). The crowns were then demineralized for 7 d in vitro (0.1 mol/1 acetate, 1 mmol/l Ca and phosphate, pH 5.0) to produce artificial caries-like lesions. Lesions were assessed by cross-sectional microhardness profiles, and mineral loss (AZ, μm x vol% mineral) calculated. Mineral loss (AZ) values decreased linearly with the square root of time of pretreatment by whole saliva, confirming a time-dependent protective effect of salivary pellicle against demineralization of enamel. Pretreatments (168 h) by whole saliva (group 1), dialyzed saliva (group 2), and lipid/'flow through" proteins (group 5) gave equivalent protection (approximately 55%). However, no protection was provided by DEAE-separated protein fractions (no lipid present) or by the mineral alone. The protection of surface enamel against demineralization appears to be given by a combination of specifically adsorbed salivary lipids and proteins.

scholarly journals Remineralization of enamel caries by an amelogenin-derived peptide and fluoride in vitro

2020 ◽  
Vol 7 (3) ◽  
pp. 283-292 ◽  
Author(s):  
Longjiang Ding ◽  
Sili Han ◽  
Kun Wang ◽  
Sainan Zheng ◽  
Wenyue Zheng ◽  
...  
Keyword(s):  
Tooth Enamel ◽  
The Novel ◽  
Oral Diseases ◽  
Surface Microhardness ◽  
Enamel Caries ◽  
Low Concentrations ◽  
The World ◽  
Mineral Loss ◽  
Hydroxyapatite Crystals

Abstract Dental caries is one of the most common oral diseases in the world. This study was tantamount to investigate the combinatory effects of an amelogenin-derived peptide (called QP5) and fluoride on the remineralization of artificial enamel caries. The peptide QP5 was synthesized and characterized, and the binding capability of the peptide on hydroxyapatite (HA) and demineralized tooth enamel surface was analysed. Then, the mineralization function of the peptide and fluoride was studied through the spontaneous mineralization testing and remineralization on enamel caries in vitro. First, the novel peptide QP5 could bind on the hydroxyapatite and demineralized tooth enamel surfaces. Second, QP5 can transitorily stabilize the formation of amorphous calcium phosphate and direct the transformation into hydroxyapatite crystals alone and in combination with fluoride. In addition, compared to blocks treated by peptide QP5 alone or fluoride, the sample blocks showed significantly higher surface microhardness, lower mineral loss and shallower lesion depth after treatment with a combination of QP5 and fluoride at high or low concentrations. The peptide QP5 could control the crystallization of hydroxyapatite, and combinatory application of peptide QP5 and fluoride had a potential synergistic effect on the remineralization of enamel caries.

scholarly journals Effect of fluoridated varnish and silver diamine fluoride solution on enamel demineralization: pH-cycling study

2006 ◽  
Vol 14 (2) ◽  
pp. 88-92 ◽  
Author(s):  
Alberto Carlos Botazzo Delbem ◽  
Maurício Bergamaschi ◽  
Kikue Takebayashi Sassaki ◽  
Robson Frederico Cunha
Keyword(s):  
Surface Microhardness ◽  
Cross Sectional ◽  
Silver Diamine Fluoride ◽  
Fluoride Solution ◽  
Treatment Groups ◽  
Enamel Demineralization ◽  
Percentage Loss ◽  
Ph Cycling ◽  
Mineral Loss ◽  
Silver Fluoride

OBJECTIVE: In the present investigation, the anticariogenic effect of fluoride released by two products commonly applied in infants was evaluated. METHODS: Bovine sound enamel blocks were randomly allocated to each one of the treatment groups: control (C), varnish (V) and diamine silver fluoride solution (D). The blocks were submitted to pH cycles in an oven at 37ºC. Next, surface and cross-sectional microhardness were assessed to calculate the percentage loss of surface microhardness (%SML) and the mineral loss (deltaZ). The fluoride present in enamel was also determined. RESULTS: F/Px10-3 (ANOVA, p<0.05) in the 1st layer of enamel before pH-cycling were (C, V and D): 1.61ª; 21.59b and 3.98c. The %SMH (Kruskal-Wallis, p<0.05) were: -64.0ª, -45.2b and -53.1c. %deltaZ values (ANOVA, p<0.05) were: -18.7ª, -7.7b and -17.3ª. CONCLUSION: The data suggested that the fluoride released by varnish showed greater interaction with sound enamel and provided less mineral loss when compared with silver diamine solution.

scholarly journals Histological and microhardness evaluation of early artificial carious lesions in human and bovine enamel: in vitro study

2013 ◽  
Vol 16 (4) ◽  
pp. 49
Author(s):  
Allan Kenji Masuda ◽  
Mayra Fidelis Zamboni Quitero ◽  
Luciana Cardoso Espejo-Trung ◽  
Maria Aparecida Alves Cerqueira Luz
Keyword(s):  
Polarized Light ◽  
In Vitro Study ◽  
The Body ◽  
Polarization Microscopy ◽  
Cross Sectional ◽  
Enamel Caries ◽  
Carious Lesions ◽  
Ph Cycling ◽  
Bovine Enamel

<p><strong>Objective: </strong>Early carious lesions in bovine and humanenamel developed in vitro using a pH cycling regimenwere compared. <strong>Material and Methods: </strong>Fifteencentral bovine incisors and fifteen recently extractedhuman third molars were randomly divided into twogroups: ten for the cross-sectional microhardness test(MT) and five for polarized light microscopy (PLM)analysis. Enamel blocks measuring 5 x 5 mm weremade from the buccal face of the teeth. The blocksused for the MT were sliced into two halves: “A” and“B”. “A” slices were embedded in acrylic resin, withthe face of the dentin-enamel junction left exposedfor the MT prior to pH cycling. “B” slices and wholeblocks were coated with acid-resistant varnish,except a 3 x 3 mm central window, and submitted tothe pH cycling regimen (demineralizing solution for3 h and remineralizing solution for 21 h) over fiveconsecutive days. The “B” slices were then submittedto the MT and the whole blocks were processed forthe PLM study. <strong>Results: </strong>The PLM analysis revealedshallow, extensive lesions in the bovine enamel,hardly showing the superficial, dark and translucentzones, as well as deep cavity lesions in the humanenamel, with the body of the lesion and the darkzone evident. The MT revealed a significant decreasein microhardness in the superficial levels of thebovine enamel caries and at all depth levels of thehuman enamel caries. <strong>Conclusion: </strong>The pH cyclingregimen adopted led to the development of deeperand more demineralized carious lesions in humanenamel than bovine enamel</p><p>Keywords<br />Dental caries; Dental enamel; Microhardness tests; Polarization microscopy.</p>

Mechanical Properties of Experimental Non-Latex Orthodontic Elastic Bands

2020 ◽  
Vol 897 ◽  
pp. 185-189
Author(s):  
Sasatorn Malanon ◽  
Surachai Dechkunakorn ◽  
Niwat Anuwongnukroh ◽  
Pongdhorn Sea-Oui ◽  
Puchong Thaptong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tooth Movement ◽  
Orthodontic Tooth Movement ◽  
Mechanical Tests ◽  
Lower Percentage ◽  
Internal Diameter ◽  
Cross Sectional ◽  
Force Decay ◽  
Extension Force

. Elastics, a source of continuous orthodontic force, are divided into two types, latex and non-latex, which are made from natural rubber and synthetic rubber, respectively. The major advantage of natural latex elastics is its resiliency to intraoral tractive forces. However, as the incidence of allergic reactions to natural latex has become more widely recognized, non-latex orthodontic elastics have been developed as an alternative. The aim of this study is to investigate the in vitro mechanical properties of Thai non-latex orthodontic elastics as compared to commercially available products. 30 samples of each two Thai non-latex elastics (MTEC1, MTEC2) and two commercial elastics (AO, GAC) with a specified diameter of ¼ inches were used. Width, cross-sectional thickness (CT), and internal diameter (ID) of all samples were measured. Mechanical tests were then carried out to determine the initial extension force (F0), 24-hour residual force (F24), and percentage of force decay. The data were analyzed with one-way ANOVA and Tukey’s test (p < 0.05). Statistically significant differences in elastic width among all four groups except between the Thai non-latex groups (MTEC1 and MTEC2) were found. AO elastics showed the greatest CT followed by GAC, MTEC2 and MTEC1. ID was significantly highest in GAC elastics and lowest in MTEC1 elastics. Although MTEC1 elastics had the lowest F0, the force still falls within the acceptable range for tooth movement (100-250g or 0.981–1.471N). MTEC2 elastics had the greatest F24 and also the lowest percentage of force decay followed by MTEC1, GAC, and AO elastics, which displayed the highest force decay, though no significant differences were found between the two commercial elastics. Thai non-latex elastics are suitable for orthodontic tooth movement due to its lower percentage of force decay after 24 hours.

scholarly journals Finding fossils in Malapa breccia – medical CT scanning or micro-CT scanning?

2017 ◽  
Vol 113 (11/12) ◽  
Author(s):  
Jacqueline S. Smilg
Keyword(s):  
Computed Tomography ◽  
Lower Energy ◽  
Ct Scanning ◽  
Cost Effective ◽  
High Energy ◽  
X Rays ◽  
Micro Ct ◽  
X Ray ◽  
Mechanical Preparation ◽  
X Ray Computed

Computed tomography (CT) imaging of fossils has revolutionised the field of palaeontology, allowing researchers to gain a better understanding of fossil anatomy, preservation and conservation. Micro focus X-ray computed tomography (μXCT) has been far more extensively used for these purposes than medical CT (XCT) – mostly because of the exquisite detail that the μXCT scanning modality, using slices of micron thicknesses, can produce. High energy X-rays can potentially penetrate breccia more effectively than lower energy beams. This study demonstrates that lower energy beams produce superior images for prioritising breccia for preparation. Additionally, XCT scanners are numerous, accessible, fast and relatively cost-effective when compared to μXCT scanners – the latter are not freely available, scanning times are much longer and there are significant limitations on the size and weight of scannable objects. Breccia blocks from Malapa were scanned at high and lower energy and images were analysed for image quality, artifact and certainty of diagnosis. Results show that lower energy images are deemed superior to higher energy images for this particular application. This finding, taken together with the limitations associated with the use of μXCT for the imaging of the large breccia from Malapa, shows that XCT is the better modality for this specific application. The ability to choose fossil-bearing breccia, ahead of manual mechanical preparation by laboratory technicians, would allow for the optimal use of limited resources, manual preparatory skills as well as the curtailment of costs.

scholarly journals Effect of starch on the cariogenic potential of sucrose

2005 ◽  
Vol 94 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Cecilia C. C. Ribeiro ◽  
Cínthia P. M. Tabchoury ◽  
Altair A. Del Bel Cury ◽  
Livia M. A. Tenuta ◽  
Pedro L. Rosalen ◽  
...  
Keyword(s):  
Animal Studies ◽  
Amylase Activity ◽  
Negative Control ◽  
Cross Sectional ◽  
Dental Biofilm ◽  
Enamel Demineralization ◽  
Two Phases ◽  
Mineral Loss

Sincein vitroand animal studies suggest that the combination of starch with sucrose may be more cariogenic than sucrose alone, the study assessedin situthe effects of this association appliedin vitroon the acidogenicity, biochemical and microbiological composition of dental biofilm, as well as on enamel demineralization. During two phases of 14 d each, fifteen volunteers wore palatal appliances containing blocks of human deciduous enamel, which were extra-orally submitted to four groups of treatments: water (negative control, T1); 2 % starch (T2); 10 % sucrose (T3); and 2 % starch+10 % sucrose (T4). The solutions were dripped onto the blocks eight times per day. The biofilm formed on the blocks was analysed with regard to amylase activity, acidogenicity, and biochemical and microbiological composition. Demineralization was determined on enamel by cross-sectional microhardness. The greatest mineral loss was observed for the association starch+sucrose (P<0·05). Also, this association resulted in the highest lactobacillus count in the biofilm formed (P<0·05). In conclusion, the findings suggest that a small amount of added starch increases the cariogenic potential of sucrose.

A Spectroscopic and Surface Microhardness Study on Enamel Exposed to Beverages Supplemented with Lower Iron Concentrations

2015 ◽  
Vol 39 (2) ◽  
pp. 161-167 ◽  
Author(s):  
AM Xavier ◽  
K Rai ◽  
AM Hegde ◽  
S Shetty
Keyword(s):  
Artificial Saliva ◽  
Permanent Teeth ◽  
Surface Microhardness ◽  
Human Enamel ◽  
Group 2 ◽  
Student’S T ◽  
Acidic Beverages ◽  
Mineral Loss ◽  
Iron Concentrations

Objectives: This study aimed to compare the in vitro mineral loss and surface microhardness (SMH) changes in human enamel specimens following supplementation of acidic carbonated beverages with low iron concentrations than when treated without. Study Design: 180 enamel blocks each from primary and permanent teeth were prepared and equally subdivided (n=10) for their respective treatments in Group 1 (Coca Cola and Sprite without iron supplementation) and Group 2 (beverages supplemented with 2/5mmol/L FeSO4.7H2O). Following initial SMH estimation, the blocks were subjected to 3 treatment cycles of 5/20 minute incubation periods, equally interspaced by a 5-min treatment in artificial saliva. The calcium and phosphate released after each cycle were analyzed spectrophotometrically and the final SMH was recorded. The results were tested using student's T test, One-way ANOVA and Kruskal Walli's test (p&lt;0.05). Results: Two and five mmol/L FeSO4.7H2O supplementation produced a highly significant SMH change and calcium and phosphate reduction than when treated without (p&lt;.0005). Both the enamel specimens showed similar patterns of mineral loss and SMH reduction, with pronounced effects in the twenty minute incubation cycles. Conclusion: Our results suggest that 2mmol/L FeSO4.7H2O supplementation to acidic beverages is beneficial in reducing mineral loss and preserving surface microhardness of human enamel.

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