| 1. |
- Alexandersen, V, et al.
(författare)
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Aspects of teeth from archaelogic sites in Sweden and Denmark.
- 1998
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Ingår i: Acta odontologica Scandinavica. - : Informa UK Limited. - 0001-6357 .- 1502-3850. ; 56:1, s. 14-9
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to examine ground sections of primary second molars and permanent first molars from the same jaws. Teeth from 11 individuals were collected from archaeologic sites in Sweden and Denmark. Longitudinal buccolingual sections were examined in a polarization light microscope and in a Philips scanning electron microscope (SEM). The seven teeth from Sweden appeared to have been subjected to environmental influences at their burial site, which had affected both the dentin and the enamel. The teeth from the Danish sites had a normal color, and no disintegration of the dentin was seen. The general morphologic appearance was normal in all primary and permanent teeth. The position of the neonatal line indicated a normal full-term gestational age. The observed accentuated incremental lines in both the primary and permanent enamel suggested periods of dietary changes, possibly related to periods of illness. SEM images of the surface area of the Swedish teeth showed an extremely porous enamel surface with severe changes in the prism structure as an effect of acid penetration. The Danish teeth did not show any marked changes in the enamel.
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| 2. |
- Almhöjd, Ulrica S., et al.
(författare)
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Analysis of carious dentine using FTIR and ToF-SIMS.
- 2014
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Ingår i: Journal of Oral Health and Dental Management. - 1583-5588. ; 13:3, s. 735-744
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Apart from the Maillard reaction, other processes, such as esterification, take place in carious tissue. The aim of the present study was to analyse sound and carious dentine in terms of ester groups and their reaction with hydrazine derivate using Fourier Transform Infrared Spectroscopy (FTIR) and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). Carious and sound dentine from human premolars were excavated in three series (Experimental Parts I-III) and separated into inner and outer layers of carious dentine. The excavated tooth material was analysed with FTIR (Part I). Carious and sound dentine were also exposed to different chemical treatments and analysed with FTIR-Attenuated Total Reflectance (FTIR-ATR; Part II) and ToF-SIMS (Part III). The FTIR absorption spectra showed that the carious tissue contained ester groups, not detected in sound dentine. The results also indicated a higher occurrence of ester groups in the inner dental caries layer than in the outer ones. Potential binding to these ester groups by hydrazine derivative was observed after different chemical treatments with both FTIR-ATR and ToF-SIMS. The results of the present study revealed ester groups unique to the carious dentine which, after reaction with hydrazine derivative, form a covalent bond not found in sound dentine. The staining of carious unique groups would be clinically helpful in detection and prevention unnecessary removal of sound dentine.
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| 3. |
- Almhöjd, Ulrica S., et al.
(författare)
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Molecular Insights into Covalently Stained Carious Dentine Using Solid-State NMR and ToF-SIMS
- 2017
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Ingår i: Caries Research. - : S. Karger AG. - 0008-6568 .- 1421-976X. ; 51:3, s. 255-263
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Tidskriftsartikel (refereegranskat)abstract
- Dyes currently used to stain carious dentine have a limited capacity to discriminate normal dentine from carious dentine, which may result in overexcavation. Consequently, finding a selective dye is still a challenge. However, there is evidence that hydrazine-based dyes, via covalent bonds to functional groups, bind specifically to carious dentine. The aim of this study was to investigate the possible formation of covalent bonds between carious dentine and N-15(2)-hydrazine and the hydrazine-based dye, N-15(2)-labelled Lucifer Yellow, respectively. Powdered dentine from extracted carious and normal teeth was exposed to the dyes, and the staining reactions were analysed using time-of-flight secondary ion mass spectrometry (ToF-SIMS), solid-state C-13-labelled nuclear magnetic resonance (NMR) and N-15-NMR spectroscopy. The results showed that N-15(2)-hydrazine and N-15(2)-labelled Lucifer Yellow both bind to carious dentine but not to normal dentine. It can thus be concluded that hydrazine-based dyes can be used to stain carious dentine and leave normal dentine unstained. (C) 2017 S. Karger AG, Basel
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| 4. |
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| 5. |
- Andreasen, F M, et al.
(författare)
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Long-term survival of fragment bonding in the treatment of fractured crowns: a multicenter clinical study.
- 1995
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Ingår i: Quintessence international (Berlin, Germany : 1985). - 0033-6572. ; 26:10, s. 669-81
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Tidskriftsartikel (refereegranskat)abstract
- In three Scandinavian dental facilities, a series of 334 permanent incisors with fractures of the crown or crown and root was treated by reattachment of the fragment with a resin composite. Two centers (Oslo and Stockholm) employed acid etching of enamel alone for fragment bonding (n = 146), while the third center (Copenhagen) used a combination of enamel etching and dentinal bonding (n = 188). Although the final retention rate of fragment bonding was similar in the two groups, it took the dentinal bonding group almost three times as long to drop to 50% fragment retention. This difference could be attributed to greater bonding strength in the dentinal bonding group, greater risk of second injury in the younger acid-etching group, or difficulty in maintaining a dry operative field in the younger age group. The good fragment retention, acceptable esthetics, and pulpal vitality observed in the present series indicate that reattachment of the coronal fragment is a realistic alternative to placement of conventional resin-composite restorations.
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| 6. |
- Bjarnason, Sibilia, et al.
(författare)
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Bonded resin sealant on smooth surface dental enamel--an in vitro study.
- 2003
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Ingår i: Swedish dental journal. - 0347-9994. ; 27:4, s. 167-74
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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.
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| 7. |
- Bjarnason, Sibilia, et al.
(författare)
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Enamel fluoride and caries in Icelandic children and a comparison of enamel fluoride in Swedish and Icelandic children.
- 1989
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Ingår i: Caries research. - 0008-6568. ; 23:2, s. 87-91
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Tidskriftsartikel (refereegranskat)abstract
- The fluoride content in surface enamel and its relationship to caries experience was studied in a group of Icelandic schoolchildren living in a low-fluoride area. Fluoride content was assessed by means of in vivo enamel biopsies sampled from 248 subjects aged 11 and 12 years. Dental examinations were performed in conjunction with the biopsy sampling and by the same examiner 1 year later. The prevalence and incidence of initial (DSI) and manifest (DFS) caries lesions were recorded separately. A median fluoride concentration of 610 ppm at a median biopsy depth of 4.2 microns was observed. A significant positive correlation was found between DSI and enamel fluoride content in girls and all older children. Additionally, surface enamel fluoride was measured in 72 Swedish children from a low-fluoride area but exposed to regular topical fluoride treatments. The difference in mean fluoride concentrations between the Icelandic and Swedish study populations was highly significant. From the measured fluoride concentrations the enamel fluoride profiles for both study populations were constructed. The differences in fluoride content were most pronounced in the outermost layer, apparently reflecting the higher exposure to and acquisition of topical fluoride in the Swedish children.
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| 8. |
- Bjarnason, Sibilia, et al.
(författare)
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Sugar consumption and caries experience in 12- and 13-year-old Icelandic children.
- 1989
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Ingår i: Acta odontologica Scandinavica. - 0001-6357. ; 47:5, s. 315-21
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Tidskriftsartikel (refereegranskat)abstract
- Dietary habits with regard to sugar consumption and caries experience were studied in a group of 275 Icelandic children aged 12 and 13 years. The pattern of meals and sugar-containing food intake frequency were assessed by means of a dietary questionnaire. All dental examinations were performed by one examiner, using standardized methods and diagnostic criteria. Only 75% of the children had three regular meals daily. Breakfast and lunch were the most frequently omitted meals. Sweet buns were consumed by 32% of the children with meals and by 58% between meals, whereas soft drinks were consumed by 42% and 46%, respectively. Eighty-three per cent of the children reported eating sweets daily. The most popular products included confectionery, buns, cakes, and soft drinks, which constituted 53% of the intake with meals and 68% of that between meals. A higher caries incidence was associated with frequent intake of buns and cakes with meals and confectionery.
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| 9. |
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| 10. |
- Bäckman, B, et al.
(författare)
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The absence of correlations between a clinical classification and ultrastructural findings in amelogenesis imperfecta.
- 1993
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Ingår i: Acta odontologica Scandinavica. - 0001-6357. ; 51:2, s. 79-89
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Tidskriftsartikel (refereegranskat)abstract
- This study was performed to examine whether a clinical classification of different phenotypes of amelogenesis imperfecta could be discernible at the ultrastructural level. Seventeen primary teeth from 16 children with hypomineralization, hypomaturation, or hypoplastic variants of the disease were collected for histologic studies of the enamel by means of polarized light microscopy, scanning electron microscopy (SEM), and secondary ion mass spectrometry (SIMS). Polarization microscopy showed that the enamel was hypomineralized; in six teeth a wavy configuration of the enamel prisms also appeared. Three histomorphologic main types could be discerned. In 10 of the teeth extensive hypomineralization of the bulk of the enamel was found. One tooth had an unusually thick enamel with only a thin normally mineralized surface layer. SIMS images showed less pronounced signals from Ca2+ and Na+ but with stronger signals from Cl- and CN-, representing the organic component of enamel. The SEM images showed an irregular prism pattern with marked interprismatic areas. Irrespective of the clinical appearance or the hereditary pattern the main findings were hypomineralized enamel with or without wavy bands. Neither of the analytical methods used in this paper distinguishes between the clinical phenotypes of amelogenesis imperfecta.
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