• Imaging Science in Dentistry
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• v.45 no.3
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• pp.181-185
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• 2015

Numerous cases of enamel renal syndrome have been previously reported. Various terms, such as enamel renal syndrome, amelogenesis imperfecta and gingival fibromatosis syndrome, and enamel-renal-gingival syndrome, have been used for patients presenting with the dental phenotype characteristic of this condition, nephrocalcinosis or nephrolithiasis, and gingival findings. This report describes a case of amelogenesis imperfecta of the enamel agenesis variety with nephrolithiasis in a 21-year-old male patient who complained of small teeth. The imaging modalities employed were conventional radiography, cone-beam computed tomography, and renal sonography. Such cases are first encountered by dentists, as other organ or metabolic diseases are generally hidden. Hence, cases of amelogenesis imperfecta should be subjected to advanced diagnostic modalities, incorporating both dental and medical criteria, in order to facilitate comprehensive long-term management.

• KSBB Journal
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• v.29 no.2
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• pp.112-117
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• 2014

The purpose of this study was to evaluate the influence of energy drinks on the erosion of dental enamel and mouse teeth growth. Exposure of enamel surface to energy drinks stimulated the release of the calcium from enamel surface of teeth. And the surface microhardness of enamel decreased after immersion in energy drinks. Enamel demineralization effects under energy drinks were observed by scanning electron microscope. Effect of maternal energy drink intake on tooth morphology of offsprings was analyzed. We concluded that the energy drinks produced a significant erosion of dental enamel.

• International Journal of Oral Biology
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• v.41 no.2
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• pp.89-96
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• 2016

Tooth development shows dynamic morphological changes from the stages of cap to hard tissue formation and is strictly regulated during development. In the present study, we compared expression and localization of 3 major enamel matrix proteins in rats: amelogenin, enamel and ameloblastin. DD-PCR and RT-PCR revealed differential expression of the major proteins from the cap stage to root stage. Immunofluorescence staining results indicated that amelogenin was not detected in either inner enamel epithelium or reduced enamel epithelium, but highly immunoreactive in preameloblasts and ameloblasts; in addition, it was sporadically expressed in preodontoblasts abutting preameloblasts. Ameloblastin expression was also observed in not only differentiated ameloblasts but also osteoblasts. Immunoreactivity to ameloblastin in ameloblasts was strong in Tomes' processes. Enamelin was exclusively localized along the entire newly formed and maturing enamel. Enamelin was largely localized in near Tomes' processes and enamel rods in maturing enamel. Alendronate treatment resulted in down-regulation of amelogenin and ameloblastin at both transcription and translation levels; whereas, enamelin expression was unchanged in response to the treatment. These results suggested that amelogenin, ameloblastin and enamelin might be implicated in cell differentiation, adhesion of ameloblasts to enamel and enamel crystallization during enamel matrix formation, respectively.

• Journal of Technologic Dentistry
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• v.26 no.1
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• pp.115-128
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• 2004

In this study, optical and mechanical properties were investigated with 4 kinds of commercial dental enamels. As a result of EDS analysis $SiO_2,\;Na_{2}O,\;Al_{2}O_3\;and\;K_{2}O$ were the main components of commercial dental enamels. In case of H specimen, content of $SiO_2\;and\;K_2O$ were more than that of another specimens. Starting powder and fired specimens were glass ceramics which were consist of amorphous phase and leucite (crystalline) phase. Crystallization did not occurred during firing process, since the XRD peak intensity was similar between starting powder and fired specimens. As a result of differential thermal analysis, $T_g$ and crystalline temperature was varied with composition in the range of $548\sim576^{\circ}C$ and $735\sim780^{\circ}C$ respectively. 0.5mm thickness dental enamel specimens showed sufficient translucent properties. However, transmittance and reflectance were lower than 5% result from scattering due to the refractive index difference between glass and crystalline phase. 3 point bending strength was in the range of 73.9$\sim$101.8MPa which was similar or slightly higher than enamel of natural teeth and Vickers hardness was higher than enamel of natural teeth more than 100.

• The Journal of the Korean dental association
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• v.9 no.4
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• pp.151-157
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• 1971

Freshly extracted permant teeth were examined by electron microscope according to the Filmy replica method. Preparatory method with hydrochloric acid or proteolytic enzyme treatment was used in order to injure the structural composition of enamel surface to compare between the natural carious defects and the etched samples used in this study. The natural carious defects were chalky white or brown discolored portions at the smooth enamel surface without having visible loss of enamel substances. The findings were as follows: 1. The first caries attact initiated from the mineralized portion of rod sheath which is located at the top of enamel rod. 2. The caries developed downward along the rod sheath interprismatic substances and enamel rods subsequently. However, the caries involvement of interprismatic substances and enamel rods occured almost at the same time. 3. The rod sheath attached to the remineralized smooth emael surface was located at the top of enamel rod.

• Journal of Korean society of Dental Hygiene
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• v.17 no.5
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• pp.817-826
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• 2017

Objectives: The aim of this study was to investigate the effects of bamboo salts on remineralization effects on subsurface of artificial carious enamel. Methods: Incipient carious enamel was formed in permanent bovine incisors and then specimens were divided into three groups randomly: 3% bamboo salt (BS), 2% (NaF) and the solution of mixed 3% BS and 2% NaF. For remineralization, specimens of each of the three groups were treated for 24 hrs at $37^{\circ}C$ incubator. After treatment, specimens were analyzed using SEM and VHN. Statistical analysis used was one-way ANOVA. Results: In SEM observation, the BS group showed narrower distances between enamel rods than the cases of incipient subsurface caries enamel. The NaF and BS+NaF groups showed that the enamel rods near the surface were destructed, and innumerable round small particles were deposited near the surface of enamel. The BS+NaF group showed more minerals attachment between enamel rods than the cases of other groups. The differences in subsurface microhardness (${\Delta}VHN$) increased all of three groups in total by $80{\mu}m$. The ${\Delta}VHN$ of the BS+NaF group increased significantly more than NaF and BS groups in depth of $50{\mu}m$, $80{\mu}m$. Conclusions: The 3% bamboo salt with 2% NaF solution was found to increase subsurface hardness of incipient caries enamel. Thus, bamboo salt will be used to contribute to prevention on dental caries.

• Journal of dental hygiene science
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• v.13 no.4
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• pp.461-470
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• 2013

In order to examine the anticariogenic effect after fluoride varnish was applied to sound enamel and artificial caries enamel, anterior teeth of healthy cattle were used and divided into four groups such as group 1 (sound enamel), group 2 (application of fluoride varnish to sound enamel), group 3 (artificial caries enamel) and group 4 (application of fluoride varnish to artificial caries enamel). Remineralization on the surface of enamel and changes of crystalline structure after demineralization were observed by using a field emission scanning electron microscope (FE-SEM). Quantitative analysis of Ca and P was measured by using the energy dispersive X-ray spectrophotometer (EDS). The following conclusions were obtained: 1)Surface pattern of enamel was the roughest in group 3 due to the defects caused by porosity and microcracks. Group 4, group 1 and group 2 were followed in order; 2) It was found that pattern of crystalline structures in a group of application of fluoride varnish and a group of no application showed bigger change in artificial caries enamel than that in sound enamel. In other words, groups 4 and 1 showed a similar pattern; 3) The contents of Ca and P were higher in groups of application of fluoride varnish (group 2 and group 4) than in groups of no application of fluoride varnish (group 1 and group 3). Taken results of this study together, in the case of application of fluoride varnish, crystalline structure was changed by remineralization even in the sound enamel. In particular, porous structures showed a smooth and uniform pattern due to the recalcification in the artificial caries enamel. In addition, according to results of EDS analysis, the contents of Ca and P were increased and it had great anticariogenic effects which inhibit decalcification of sound enamel and artificial caries enamel.

• 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.

• The Journal of Advanced Prosthodontics
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• v.13 no.5
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• pp.281-291
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• 2021

PURPOSE. To evaluate the wear of computer-aided design/computer-aided manufacturing (CAD-CAM) dental ceramic materials opposed by enamel as a function of increased chewing forces. MATERIALS AND METHODS. The enamel cusps of healthy human third molar teeth (n = 40) opposed by materials from CAD-CAM dental ceramic groups (n = 10), including Vita Enamic^® (ENA), a polymer-infiltrated ceramic network (PICN); GC Cerasmart^® (CERA), a resin nanoceramic; Celtra^® Duo (DUO), a zirconia-reinforced lithium silicate (ZLS) ceramic; and IPS e.max ZirCAD (ZIR), a polycrystalline zirconia, were exposed to chewing simulation (1,200,000 cycles; 120 N load; 1 Hz frequency; 0.7 mm lateral and 2 mm vertical motion). The wear of both enamel cusps and materials was quantified using a 3D laser scanner, and the wear mechanisms were evaluated by scanning electron microscopy (SEM). The results were analysed using Welch ANOVA and Kruskal Wallis test (α = .05). RESULTS. ZIR showed lower volume loss (0.02 ± 0.01 mm³) than ENA, CERA and DUO (P = .001, P = .018 and P = .005, respectively). The wear of cusp/DUO [0.59 mm³ (0.50-1.63 mm³)] was higher than cusp/CERA [0.17 mm³ (0.04-0.41 mm³)] (P = .007). ZIR showed completely different wear mechanism in SEM. CONCLUSION. Composite structured materials such as PICN and ZLS ceramic exhibit more abrasive effect on opposing enamel due to their loss against wear, compared to uniform structured zirconia. The resin nano-ceramic causes the lowest enamel wear thanks to its flexible nano-ceramic microstructure. While zirconia appears to be an enamel-friendly material in wear volume loss, it can cause microstructural defects of enamel.

• Journal of Korean society of Dental Hygiene
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• v.8 no.3
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• pp.13-22
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• 2008

Objectives: The purpose of this study was to identify the correlation between calcium in soft drinks and enamel remineralization. Method: Six soft drinks were used in this study. These were calcium milk, normal milk, calcium yoghurt, normal yoghurt, calcium orange juice, and orange juice. Enamel specimens which 300- 400Vickers Hardness Number (VHN) were selected. These samples were immersed in each soft drink for 12 hours in an in vitro remineralization model. All specimens were processed for SEM image of the enamel surface. Results were analyzed by SPSS 13.0 package program. Results: Calcium milk was the most influential and normal yoghurt was the least to enamel surface. There was not significant difference according to calcium supplement in milk although the difference of enamel hardness was ${\Delta}f13.4$ in calcium milk, and ${\Delta}f4.7$ in normal milk (P>0.05). Other soft drinks showed a little change about calcium but they were insignificant. Demineralization effect was remarkably observed in calcium yoghurt ($-{\Delta}f269.1$) and this effect was confirmed by SEM images. In conclusion, calcium supplemented soft drinks had little influences to hardness of enamel surface.