| 1. |
- Bjarnason, Sibilia, et al.
(författare)
-
Bonded resin sealant on smooth surface dental enamel--an in vitro study.
- 2003
-
Ingår i: Swedish dental journal. - 0347-9994. ; 27:4, s. 167-74
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to in vitro evaluate the micro leakage of a fissure sealant on sound and demineralized enamel using thermo cycling. The effect of the sealing procedure on sound and demineralized enamel were assessed on human premolars that were divided into one Control group and two Test groups. The Control group served as a baseline reference for the subsequent test procedures. The crowns of five teeth were covered with wax leaving three separate windows on the buccal surfaces. The enamel in one window was acid-etched, in the second window demineralized, and in the third window demineralized and subsequently acid-etched. In Test group 1, containing ten teeth, a defined enamel area on the buccal surfaces was acid-etched and sealed. The sealed area and a border of sound enamel around it were subjected to the demineralizing procedure. In Test group 2, a defined enamel window of 13 teeth was demineralized and subsequently etched and sealed. The sealed area and a border of surrounding enamel were subjected to a new cycle of demineralization. The longitudinal, bucco-lingual sections were examined in polarized light. When placed on acid-etched surfaces, the resin adhered firmly to the enamel with no evidence of demineralization or enlargement of previously demineralized areas underneath the sealants.
|
|
| 2. |
- Fagrell, Tobias G, et al.
(författare)
-
Chemical, mechanical and morphological properties of hypomineralized enamel of permanent first molars.
- 2010
-
Ingår i: Acta odontologica Scandinavica. - : Informa UK Limited. - 1502-3850 .- 0001-6357. ; 68:4, s. 215-22
-
Tidskriftsartikel (refereegranskat)abstract
- The microstructure of hypomineralized enamel in permanent teeth has been described in several studies as less distinct prism sheaths and disorganized enamel with lack of organization of the enamel crystals. The mechanical properties, hardness and modulus of elasticity of the hypomineralized enamel have lower values compared with normal. The aim of this study was to examine normal and hypomineralized enamel using scanning electron microscopy (SEM), hardness measurements and X-ray microanalysis (XRMA).
|
|
| 3. |
- Fagrell, Tobias G, et al.
(författare)
-
Effect of ozone treatment on different cariogenic microorganisms in vitro.
- 2008
-
Ingår i: Swedish dental journal. - : Swedish Dental Association. - 0347-9994. ; 32:3, s. 139-47
-
Tidskriftsartikel (refereegranskat)abstract
- Ozone treatment has been presented and discussed in the literature, as one of the "new" ways to treat dental caries. The aim of this paper was to study the in vitro effect of ozone on some common oral microorganisms related to dental caries using scanning electron microscopy (SEM). The effect of ozone was tested on three different strains of mutans streptococci and one Lactobacillus strain. After exposure of bacteria to ozone treatment for 0 to 60 sec, cultivation on different chair side strips and agar plates took place. Preparation and performance of scanning electron analyses in a field emission scanning electron microscope at 10 kV was then carried out. It was found that gaseous ozone treatment for 20 seconds or more was effective to kill the different microorganisms in vitro. Treatment of 20, 40 and 60 seconds of ozone prevented the bacteria to grow on the different media. Treatment times shorter than 20 seconds resulted in varying results with a limited effect on bacterial growth for treatments of 5-10 sec, respectively. The difference between ozone-treated and untreated specimens was macroscopically readily discernable. None of the strains treated with ozone for 60 seconds showed any bacterial growth. Only samples with untreated bacteria could be found in the SEM analyses in form of large and high colonies. This study presents a clear result of the bactericide effect of ozon (in vitro) on four different strains of bacteria associated with dental caries.
|
|
| 4. |
- Heijs, Suzanne C B, et al.
(författare)
-
Morphology and chemical composition of dentin in permanent first molars with the diagnose MIH.
- 2007
-
Ingår i: Swedish dental journal. - 0347-9994. ; 31:4, s. 155-64
-
Tidskriftsartikel (refereegranskat)abstract
- The purpose of this investigation was to study the morphology and distribution of some inorganic elements in dentin in first permanent molars from children with Molar-Incisor Hypomineralization (MIH). Sixty four tooth sections from thirty two children were examined in polarized light. Fifteen representative sections were selected for SEM/XRMA analysis; 5 were used for SEM analysis and 10 for XRMA analysis. No morphological changes in the dentin were revealed in polarized light microscopy (PLM). However, in all but two sections interglobular dentin was found. The SEM analyzes confirmed the findings of the PLM with no structural changes to be found in the dentin. The XRMA results showed a difference in the concentration of elements between dentin below normal and dentin below carious or hypomineralized enamel. Elements related to organic matter appeared with higher values in dentin below hypomineralized and carious enamel. The morphological and chemical findings in dentin below hypomineralized enamel imply that the odontoblasts are not affected in cases of MIH, but may be affected by hypocalcemia, reflected by the presence of interglobular dentin.
|
|
| 5. |
- Klingberg, Gunilla, 1960, et al.
(författare)
-
Morphological appearance and chemical composition of enamel in primary teeth from patients with 22q11 deletion syndrome.
- 2005
-
Ingår i: European journal of oral sciences. - : Wiley. - 0909-8836 .- 1600-0722. ; 113:4, s. 303-11
-
Tidskriftsartikel (refereegranskat)abstract
- Patients with 22q11 deletion syndrome have many and complex medical problems, including hypocalcemia and/or hypoparathyroidism. Odontological findings include enamel aberrations in both dentitions. In order to describe enamel morphology, chemical composition in primary teeth, and to investigate the relationship between medical history and morphological appearance, dental enamel was investigated in 38 exfoliated primary teeth from 15 children and adolescents. Morphology was studied by the use of a polarized light microscope, microradiography, scanning electron microscopy, X-ray microanalysis, and secondary ion mass spectrometry. The morphological findings were compared with medical history. The teeth showed, in principle, a normal morphological appearance with regard to prism structure. A high frequency of aberrations, such as hypomineralization, hypoplasia and extra incremental lines, were found. The majority of the aberrations were found around the neonatal line. There was a relationship between high numbers of medical problems in the patients and enamel deviations. The result supports the hypothesis of under-reporting of both hypocalcemia and hypoparathyroidism in patients with 22q11 deletion syndrome.
|
|
| 6. |
- Rizell, Sara, 1963, et al.
(författare)
-
Altered inorganic composition of dental enamel and dentin in primary teeth from girls with Turner syndrome.
- 2010
-
Ingår i: European journal of oral sciences. - : Wiley. - 1600-0722 .- 0909-8836. ; 118:2, s. 183-90
-
Tidskriftsartikel (refereegranskat)abstract
- In Turner syndrome (TS) one X-chromosome is missing or defective. The amelogenin gene, located on the X-chromosome, plays a key role during the formation of dental enamel. The aim of this study was to find support for the hypothesis that impaired expression of the X-chromosome influences mineral incorporation during amelogenesis and, indirectly, during dentinogenesis. Primary tooth enamel and dentin from girls with TS were analysed and compared with the enamel and dentin of primary teeth from healthy girls. Qualitative and quantitative changes in the composition of TS enamel were found, in addition to morphological differences. Higher frequencies of subsurface lesions and rod-free zones were seen in TS enamel using polarized light microscopy. Similarly, scanning electron microscopy showed that the enamel rods from TS teeth were of atypical sizes and directions. Using X-ray microanalysis, high levels of calcium and phosphorus, and low levels of carbon, were found in both TS enamel and dentin. Using microradiography, a lower degree of mineralization was found in TS enamel. Rule induction analysis was performed to identify characteristic element patterns for TS. Low values of carbon were the most critical attributes for the outcome TS. The conclusion was that impaired expression of the X-chromosome has an impact on dental hard tissue formation.
|
|
| 7. |
- Rythén, Marianne, et al.
(författare)
-
Chemical aspects on dental hard tissues in primary teeth from preterm infants.
- 2010
-
Ingår i: European journal of oral sciences. - : Wiley. - 1600-0722 .- 0909-8836. ; 118:4, s. 389-95
-
Tidskriftsartikel (refereegranskat)abstract
- Preterm children with very low birth weight suffer from several neonatal and postnatal complications that may affect the mineralization of teeth. Clinical and morphological studies have shown enamel aberrations in teeth from preterm children. In this study, the chemical composition in enamel and dentin was compared in primary teeth from preterm children and full-term children, and the relationship between the chemical composition and the morphological appearance was investigated. Enamel and dentin in 17 exfoliated primary teeth, from 14 children with a gestational age below 29 wk, were investigated and compared with 36 exfoliated primary teeth from full-term children, using X-ray microanalyses (XRMA). In comparison with the teeth from the controls, the teeth from preterm children had a higher relative value of carbon (C), a lower relative value of calcium (Ca), a lower ratio of calcium/phosphorus (Ca/P) and a lower ratio of Ca/C throughout the outer part of the enamel. In dentin, the relative values for P were higher, and Ca/P ratio was lower, at the dentin-pulp junction. The Ca/P ratio indicated normal hydroxyapatite in the crystals in enamel and dentin. The lower ratio of Ca/C in the bulk and outer part of the enamel indicated more porous enamel.
|
|
| 8. |
- Sabel, Nina, 1973, et al.
(författare)
-
Elemental composition of normal primary tooth enamel analyzed with XRMA and SIMS.
- 2009
-
Ingår i: Swedish dental journal. - 0347-9994. ; 33:2, s. 75-83
-
Tidskriftsartikel (refereegranskat)abstract
- There is an interest to analyze the chemical composition of enamel in teeth from patients with different developmental disorders or syndromes and evaluate possible differences compared to normal composition. For this purpose, it is essential to have reference material. The aim of this study was to, by means of X-ray micro analyses (XRMA) and secondary ion mass spectrometry (SIMS), present concentration gradients for C, O, P and Ca and F, Na, Mg, Cl, K and Sr in normal enamel of primary teeth from healthy individuals. 36 exfoliated primary teeth from 36 healthy children were collected, sectioned, and analyzed in the enamel and dentin with X-ray micro analyses for the content of C, O, P and Ca and F, Na MgCl, K and Sr. This study has supplied reference data for C, O, P and Ca in enamel in primary teeth from healthy subjects. No statistically significant differences in the elemental composition were found between incisors and molars.The ratio Ca/P is in concordance with other studies. Some elements have shown statistically significant differences between different levels of measurement. These results may be used as reference values for research on the chemical composition of enamel and dentin in primary teeth from patients with different conditions and/or syndromes.
|
|
| 9. |
- Sabel, Nina, 1973, et al.
(författare)
-
Polarized light and scanning electron microscopic investigation of enamel hypoplasia in primary teeth.
- 2010
-
Ingår i: International journal of paediatric dentistry. - 1365-263X .- 0960-7439. ; 20:1, s. 31-36
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Enamel hypoplasia is a developmental disturbance during enamel formation, defined as a macroscopic defect in the enamel, with a reduction of the enamel thickness with rounded, smooth borders. Information on the microstructural level is still limited, therefore further studies are of importance to better understand the mechanisms behind enamel hypoplasia. AIM: To study enamel hypoplasia in primary teeth by means of polarized light microscopy and scanning electron microscopy. METHODS: Nineteen primary teeth with enamel hypoplasia were examined in a polarized light microscope and in a scanning electron microscope. RESULTS: The cervical and incisal borders of the enamel hypoplasia had a rounded appearance, as the prisms in the rounded cervical area of the hypoplasia were bent. The rounded borders had a normal surface structure whereas the base of the defects appeared rough and porous. CONCLUSIONS: Morphological findings in this study indicate that the aetiological factor has a short duration and affects only certain ameloblasts. The bottom of the enamel hypoplasia is porous and constitutes possible pathways for bacteria into the dentin.
|
|
| 10. |
- Youravong, Nattaporn, et al.
(författare)
-
Chemical composition of enamel and dentine in primary teeth
- 2007
-
Ingår i: Science of the total environment. ; 389:2-3, s. 253-258
-
Tidskriftsartikel (refereegranskat)abstract
- Enamel and dentine in teeth of children with high blood levels of lead were analyzed by means of secondary ion mass spectrometry (SIMS) and X-ray micro-analyses (XRMA) and compare with teeth from children with low blood levels of lead. The SIMS analysis revealed detectable levels of Pb in dentine close to the pulp. The XRMA analyses could not detect any lead. There were no differences found in lead level in enamel of high lead level exposed teeth from low level exposed. The results confirm that children with high blood levels of lead have an uptake of lead in dentine close to the pulp.
|
|
| 11. |
- Youravong, Nattaporn, et al.
(författare)
-
Chemical composition of enamel and dentine in primary teeth in children from Thailand exposed to lead.
- 2008
-
Ingår i: The Science of the total environment. - : Elsevier BV. - 0048-9697. ; 389:2-3, s. 253-8
-
Tidskriftsartikel (refereegranskat)abstract
- Enamel and dentine in teeth of children with high blood levels of lead were analyzed by means of secondary ion mass spectrometry (SIMS) and X-ray micro-analyses (XRMA) and compare with teeth from children with low blood levels of lead. The SIMS analysis revealed detectable levels of Pb in dentine close to the pulp. The XRMA analyses could not detect any lead. There were no differences found in lead level in enamel of high lead level exposed teeth from low level exposed. The results confirm that children with high blood levels of lead have an uptake of lead in dentine close to the pulp.
|
|
| 12. |
- Youravong, Nattaporn, et al.
(författare)
-
Morphology of enamel in primary teeth from children in Thailand exposed to environmental lead.
- 2005
-
Ingår i: The Science of the total environment. - : Elsevier BV. - 0048-9697. ; 348:1-3, s. 73-81
-
Tidskriftsartikel (refereegranskat)abstract
- Lead is one of the major environmental pollutants and a health risk. Dental hard tissues have a capacity to accumulate lead from the environment. Eighty exfoliated primary teeth were collected from children residing around a shipyard area in southern Thailand, known for its lead contamination. The morphology of the enamel was examined by polarized light microscopy (PLM), microradiography (MRG), and scanning electron microscopy (SEM). The specimens derived from two groups of children, one group with high blood levels of lead (57 teeth) and one group having low blood levels of lead (23 teeth). The enamel irrespective of group appeared normal. However, in a majority of the specimens the enamel surface appeared hypomineralized, which was confirmed in SEM. No morphological changes connected to lead in blood could be found. The hypomineralized surface zone could possibly be attributed to an acid oral environment.
|
|
