Deviations of inorganic and organic carbon content in hypomineralised enamel

Objectives: The purpose of this study was to discriminate hypomineralised enamel of permanent first molars from normal enamel by means of spectroscopic methods. Methods: The present study was conducted using Multi spot Raman Fourier Transform Spectroscopy, Diffuse Reflectance Infrared Fourier Transform Spectroscopy (FTIR) and X-ray diffraction (XRD). Results: Raman-spectroscopy indicated significantly more B-type carbonate and hydrocarbons in hypomineralised enamel diagnosed as MIH (Molar Incisor Hypomineralisation). From XRD analysis, no changes in crystallinity of the enamel apatite could be found. Conclusions: Using multi spot Raman-spectroscopy, a significant molecular discrimination between normal and hypomineralised enamel could be made

Aspects on dental hard tissues in primary teeth from patients with Ehlers-Danlos syndrome

Ehlers-Danlos syndrome (EDS) is a rare hereditary condition affecting connective tissues and dental hard tissues. HYPOTHESES: Primary enamel and dentine from EDS patients were expected to differ from those of healthy subjects regarding morphology and chemical composition. DESIGN: Forty-seven exfoliated primary teeth from 25 patients with EDS were investigated. Morphology was studied using a polarized light microscope, scanning electron microscope, and X-ray microanalysis. Comparisons were made with 36 primary teeth from 36 healthy patients. RESULTS: Morphological analysis of enamel in EDS teeth showed a high frequency of postnatally hypomineralized enamel and postnatally located incremental lines, whereas dentine was normal in all patients. Chemical analysis could not reveal any differences between EDS and control patients except for lower content of C and a higher Ca/P ratio in the enamel in the EDS teeth, indicating porous enamel. Regarding dentine, EDS teeth had a lower content of C, and a higher content of Ca, P, and O. Ratios for Ca/C and Ca/O were also higher compared with controls. CONCLUSIONS: There are several aberrations of booth enamel and dentine in primary teeth from patients with EDS. These could explain the occurrence of both more dental caries and tooth fractures in patients with EDS

22q11DS : ett ovanligt vanligt syndrom

22q11-deletionssyndrom (22q11DS) är ett vanligt syndrom som förekommer hos ett av 4 000 nyfödda barn. Diagnosen har ett flertal medicinska symtom men också neuropsykiatriska och psykiska. 22q11DS påverkar även tänder, mun och oral hälsa på flera olika sätt. Det är därför viktigt att tandvårdspersonal har kännedom om diagnosen

XRMA and ToF-SIMS Analysis of Normal and Hypomineralized Enamel.

Molar incisor hypomineralization (MIH) is a developmental disturbance of the enamel. This study presents analyses of hypomineralized and normal enamel in first molar teeth diagnosed with MIH, utilizing time-of-flight secondary ion mass spectrometry area analyses and X-ray microanalysis of area and spot profiles in uncoated samples between gold lines which provide electrical conductivity. Statistical analysis of mean values allows discrimination of normal from MIH enamel, which has higher Mg and lower Na and P. Inductive analysis using complete data sets for profiles from the enamel surface to the enamel-dentin junction found that Mg, Cl and position in the profile provide useful discrimination criteria. Element profiles provide a visual complement to the inductive analysis and several elements also provide insight into the development of both normal and MIH enamel. The higher Mg content and different Cl profiles of hypomineralized enamel compared with normal enamel are probably related to a relatively short period during the development of ameloblasts between birth and the 1st year of life

Neonatal lines in the enamel of primary teeth - a morphological and scanning electron microscopic investigation

Department of Pedodontics, Faculty of Odontology, Göteborg University, Göteborg, Sweden; Department of Pediatric Dentistry, Public Dental Service, Göteborg, Sweden. OBJECTIVE: The neonatal line (NNL) is in principle found in all primary teeth and the line represents the time of birth. Earlier findings of the appearance of the NNL in light microscope and in microradiographs have shown not only changes in the prism direction of the enamel, but that the NNL has a hypomineralized character. METHODS: The neonatal line was analyzed in un-decalcified sections of primary lower and central incisors, collected from individuals of different ages utilizing polarized light microscopy, microradiography, scanning electron microscopy (SEM) and X-ray analysis (XRMA). RESULTS: In polarized light the NNL appeared to have a more porous structure than the enamel in general. The appearance of the NNL as a dark line in microradiographs is interpreted as the NNL being less mineralized than neighbouring enamel. Analysis with ImageJ visualized the reduction of the amount of grey value, indicating that the NNL is less mineralized. Analysis of the NNL in SEM showed a reduction of the diameter of enamel prisms, the more narrow diameters continued through the postnatal enamel. A change of the growth direction of the prisms was also observed at the NNL. In a three-dimensional image the NNL appeared as a grove, however, in non-etched enamel no grove was seen. The elemental analyses with XRMA showed no marked changes in the content of C, Ca, P, N, O or S in the area around the NNL. CONCLUSIONS: The NNL is an optical phenomenon due to alterations in height, and degree of mineralization of the enamel prisms. PMID: 18589400 [PubMed - in process