• Analytical Science and Technology
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• v.36 no.2
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• pp.99-104
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• 2023

Trace elements (TEs) have significant effects on both dental health and human health. Toxic effects are caused by deficiency or excess of TEs. This study was performed to determine levels of toxic and trace elements in incisor and molar teeth sampled from male and female participants residing in the north and south regions of Sudan. The tooth enamel of 18 extracted human teeth was analyzed using particle-induced x-ray emission (µ-PIXE) to determine its elemental profile and distribution. GeoPIXEII software package was used for the analysis of µ-PIXE data. The main elements determined were Na, Mg, P, S, Cl, K, Ca, Mn, Fe, Zn, Co, and Sr which were homogeneously distributed in the areas of the tooth enamel mapped with micro-PIXE.

• The korean journal of orthodontics
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• v.5 no.1
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• pp.21-24
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• 1975

The purpose of this study was to investigate the effect of sinc phosphate cement on the enamel surface of extracted teeth. The tooth was placed in a test tube, which was subjected to 5ml of 0.2M acetate buffer at pH 4 by 'window technique.' The calcium content of the acetate buffer was determined by the Perkin-Elmer Model 303 Atomic Absorption Spectrophotometer. The obtained results were summarized in the following. 1. The solubility of enamel is $0.92mg/cm^2$. ml in control group. 2. The solubility of enamel is increased by treating these with zinc phosphate cements. 3. The solubility of enamel is $0.69mg/cm^2$. ml by treating with Lee Smith cement. 4. The solubility of enamel is $0.30mg/cm^2$. ml by treating with G-C's cement.

• Restorative Dentistry and Endodontics
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• v.5 no.1
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• pp.7-12
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• 1979

After applying three types of composite resins - Hi-Pol composite with Enamel bond, Hi-Pol composite without Enamel bond, Restodent - to the intact and the ground surface of tooth that had been acid etched for one or two minutes, the author observed the penetration of these resins into the acid etched enamel surface with scanning electron microscope. The results were as follows. 1. All the experimented materials showed the penetration into the acid etched enamel surface, and the average depth of penetration was 7 microns. 2. There was no significant difference in the penetration of these three resins despite different etching, time. 3. The grinding of the Enamel surface before acid - etching was not effective in altering the depth of penetration of these materials.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.3
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• pp.513-524
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• 1998

The purpose of this study was to compare the staining ratio on the enamel surface following the use of chlorhexidine mouthwash and the chlorhexidine varnish application. Labial and lingual surfaces of maxillary and mandibular incisors of adults were selected to evaluate the staining ratio. The control group was consisted of 8 individuals, the experimental group 1 and 2 were consisted of 50 each. Prophylaxis with pumice was performed to remove the stain already established on the enamel surface of all groups. The group 1 was asked to use chlorhexidine mouthwash(Hexadent, chlorhexidine gluconate 1ml/100ml) for a minute twice a day. The chlorhexidine $varnish^{(R)}$($Chlorzoin^{(R)}$, consisted of solution 1(10% chlorhexidine acetate) and solution 2(polyurethane sealant)) was applied on the enamel surfaces of the group 2. After 4 weeks of experiment, intraoral photogragh of tooth surfaces were taken in order to record the stained area on the enamel of the control and the experimental groups. Outline of teeth and the stained area in the photographs was traced on the OHP film. Scanner and computer processor were used to calculate stained surface ratio.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.3
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• pp.640-658
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• 1996

The purpose of this study was to examine the mechanism of improving acid resistance of Nd-YAG laser irradiated tooth enamel and determine the most effective energy density for improving acid resistance. The bovine tooth enamel were lased with a pulsed Nd-YAG laser. The energy densities of exposed laser beam were varied from 10 to $70\;J/cm^2$. To investigate the degree of improving acid resistance by irradiation, all the samples were submerged to demineralize in 0.5 N $HClO_4$ solution for 1 minute. After 1 minute, 0.05 % $LaCl_3$ was added to the solution for interrupting the demineralization reaction. The amounts of dissolved calcium and phosphate in the solution were measured by using an atomic absorption spectrophotometer and the UV/VIS spectrophotometer, respectively. To examine the mechanism of improving acid resistance, X-ray diffraction analysis, infrared spectroscopy, and scanning electron microscopy were taken. The X-ray diffraction pattern of the samples were obtained in the $10^{\circ}{\sim}80^{\circ}2{\theta}$ range with $Cu-K{\alpha}$ radiation using M18HF(Mac Science Co.) with X-ray diffractometer operating at 40 KV and 300 mA. The infra-red spectra of the ground samples in 300 mg KBr pellets 10 mm diameter were obtained in the $4000cm^{-1}\;to\;400cm^{-1}$ range using JASCO 300E spectrophotometer. The scanning electron microscopy was carried out using JSM6400(JEOL Co.) with $500{\sim}2000$ times magnification. The results were as follow 1. The concentration of calcium dissolved from laser irradiated enamel with $50J/cm^2$ was significantly lesser than that of unlased control group (p<0.05) 2. From the result of the X-ray diffraction analysis, $\beta$-TCP, which increases acid solubility, was identified in lased enamel but the diffraction peaks of (002) and (004) became sharp with increasing energy density of laser irradiation. This means that the crystals in lased samples were grown through the c-axis and subsequently, the acid solubility of enamel decreased. 3. The a-axis parameter was slightly increased by laser irradiation, whereas the c-axis parameter was almost constant except for a little decrease at $50J/cm^2$. 4. In the infra-red spectra of lased enamels, phosphate bands ($600{\sim}500cm^{-1}$), B-carbonate bands (870, $1415{\sim}1455cm^{-1}$), and A-carbonate band ($1545cm^{-1}$) were observed. The amounts of phosphate bands and the B-carbonate bands were reduced, on the other hand, the amount of the A-carbonate band was increased by increase the energy density. 5. The SEM experiments reveal that the surface melting and recrystallization were appeared at $30J/cm^2$ and the cracks were observed at $70J/cm^2$. From above results, It may be suggested that the most effective energy density for improving acid resistance of tooth enamel with the irradiation of Nd-YAG laser was $50J/cm^2$. The mechanism of improving acid resistance were reduction of permeability due to surface melting and recrystallization of lased enamel and reduction of acid solubility of enamel due to decrease of carbonate content and growth of crystal.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.3
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• pp.471-476
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• 2003

The success of autotransplantation depends on the viability of periodontal ligament in the transplanted tooth. Mechanical injury to periodontal tissues frequently results in dental root resorption and ankylosis, which leads to the failure of transplantation. Enamel matrix derivative(EMD) Which contains several enamel matrix protein (amelogenin family) has been reported to be effective in some periodontal therapies has been recently used to induce periodontal regeneration. EMD promotes proliferation of periodontal ligament cells and is suggested to be useful for transplantation. In this case, we report a clinical case of EMD application in the transplantation of an impacted and immature tooth of a 14 year-old girl to enhance the periodontal regeneration.

• Restorative Dentistry and Endodontics
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• v.27 no.2
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• pp.175-182
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• 2002

Dental caries is a chronic disease that causes the destruction of tooth structure by the interaction of plaque bacteria, food debris, and saliva. There has been attempts to induce remineralization by supersaturating the Intra-oral environment around the surface enamel, where there is incipient caries. In this study, supersaturated remineralized solution "R" was applied to specimens with incipient enamel caries, and the quantitative analysis of remineralization was evaluated using microradiography. Thirty subjects volunteered to participate in this study. Removable appliances were constructed for the subjects, and the enamel specimen with incipient caries were embedded in the appliances. The subjects wore the intra-oral appliance for 15 days except while eating and sleeping. The removable appliance were soaked in supersaturated solution "R", saline, or Senstime$^{\circledR}$ to expose the specimen to those solutions three times a day, 5 minutes each time. After 15 days, microradiography was retaken to compare and evaluate remineralization The results were as the following: 1. The ratio of remineralized area to demineralized area was significantly higher in the supersaturated solution "R" and Senstime$^{\circledR}$ than in the saline (p<0.05) 2. Remineralization in the supersaturated buffer solution "R" occurred in the significantly deeper parts of the tooth. compared to the Senstime$^{\circledR}$ group containing high concentration or fluoride. (p<0.05) As in the above results, the remineralization effect of remineralized buffer solution "R" on incipient enamel caries has been proven. For clinical utilization, further studies on soft tissue reaction and the effect on dentin and cementum are necessary In conclusion compared to commercially available fluoride solution. remineralization solution“R”showed better remineralization effect on early enamel caries lesion, so it is considered as effecient solution for clinical application.

• Journal of dental hygiene science
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• v.12 no.5
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• pp.486-492
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• 2012

Immunostaing intensity of Dynamin II protein in ameloblast during mouse tooth development showed a significant increase of 48% at the postnatal day 3 and a significant increase of 50% at the postnatal day 5 as compared with the postnatal day 1, but showed a significant decrease of 16% at the postnatal day 7 and a significant decrease of 12% at the postnatal day 10 as compared with the postnatal day 1. From the above results, Dynamin II had relevance to secretion of amelogenin, ameloblastin, enamelin and matrix metalloproteinase-20 proteins for enamel formation in ameloblast. Dynamin II may be involved in the transport of vesicles containing proteins for enamel formation through the acceleration of vesicular formation and may be had a good possibility of secretory regulation of proteins for enamel formation in ameloblast. Therefore, Dynamin II have potential for being used in the field of gene theraphy for periodontal disease and in the regeneration for enamel and dentin tissues lost to dental caries.

• Restorative Dentistry and Endodontics
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• v.44 no.1
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• pp.6.1-6.11
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• 2019

Objectives: The aim of the present study was to evaluate the effect of whitening mouth rinses alone and in combination with conventional whitening treatments on color, microhardness, and surface roughness changes in enamel specimens. Materials and Methods: A total of 108 enamel specimens were collected from human third molars and divided into 9 groups (n = 12): 38% hydrogen peroxide (HP), 10% carbamide peroxide (CP), 38% HP + Listerine Whitening (LW), 10% CP + LW, 38% HP + Colgate Plax Whitening (CPW), 10% CP + CPW, LW, CPW, and the control group (CG). The initial color of the specimens was measured, followed by microhardness and roughness tests. Next, the samples were bleached, and their color, microhardness, and roughness were assessed. Data were analyzed through 2-way analysis of variance (ANOVA; microhardness and roughness) and 1-way ANOVA (color change), followed by the Tukey post hoc test. The Dunnett test was used to compare the roughness and microhardness data of the CG to those of the treated groups. Results: Statistically significant color change was observed in all groups compared to the CG. All groups, except the LW group, showed statistically significant decreases in microhardness. Roughness showed a statistically significant increase after the treatments, except for the 38% HP group. Conclusions: Whitening mouth rinses led to a whitening effect when they were used after conventional treatments; however, this process caused major changes on the surface of the enamel specimens.

• Journal of Korean society of Dental Hygiene
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• v.8 no.4
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• pp.11-18
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• 2008

The purposes of this study were to examine the effect of 35% Carbamide Peroxide(CP) bleaching agent on the changes in physical and chemical characteristics of tooth. The effect of bleaching agent on enamel was analyzed using Hardness test, SEM and EDS. The microhardness between bleached groups after bleaching showed statistically significant difference according to the paired t-test. The bleached enamel surface showed apparent morphological changes compared to the enamel, which was stored in distilled water only. The difference of the total mineral contents for the distilled water and Carbamide Peroxide did not show statistical significance. These results demonstrated that bleaching using 35% Carbamide Peroxide were adversely affects application time of experimental group and may the safety of using these agents for a short time in dentist-monitored bleaching.