European archives of paediatric dentistry : official journal of the European Academy of Paediatric Dentistry, Jan 18, 2015
In November 2014, a review of literature concerning prevalence data of Molar Incisor Hypominerali... more In November 2014, a review of literature concerning prevalence data of Molar Incisor Hypomineralisation (MIH) and Hypomineralised Second Primary Molars (HSPM) was performed. A search of PubMed online databases was conducted for relevant articles published until November 2014. The reference lists of all retrieved articles were hand-searched. Studies were included after assessing the eligibility of the full-text article. Out of 1078 manuscripts, a total of 157 English written publications were selected based on title and abstract. Of these 157, 60 were included in the study and allocated as 52 MIH and 5 HSPM, and 3 for both MIH and HSPM. These studies utilised the European Academy of Paediatric Dentistry judgment criteria, the modified index of developmental defects of enamel (mDDE) and self-devised criteria, and demonstrated a wide variation in the reported prevalence (MIH 2.9-44 %; HSPM 0-21.8 %). Most values mentioned were representative for specific areas. More studies were perfor...
A B S T R A C T The arrangement and roles of the odontoblast and its process in sensing and respo... more A B S T R A C T The arrangement and roles of the odontoblast and its process in sensing and responding to injuries such as tooth wear are incompletely understood. Evidence is presented that dentine exposure by tooth wear triggers structural and functional changes that aim to maintain tooth integrity. Mandibular first molars from freshly culled 8 week Wistar rats were prepared for light microscopy ground-sections (n = 6), or fixed in 4% paraformaldehyde, decalcified in 17% EDTA, sectioned and stained with antibodies to cyto-skeletal proteins (vimentin (vim), a-tubulin (tub) and a-actin), cellular homeostatic elements (sodium potassium ATPase (NaK-ATPase) and sodium hydrogen exchanger (NHE-1)), and sensory nerve fibres (CGRP) (n = 10) for fluorescence microscopy of worn and unworn regions of the mesial cusp. Immunoreactivity (IR) to vim, actin, NaK-ATPase and CGRP was confined to the pulpal third of odontoblast processes (OPs). IR to tub and nhe-1 was expressed by OPs in full dentine thickness. In areas associated with dentine exposure, the tubules contained no OPs. In regions with intact dentine, odontoblasts were arranged in a single cell layer and easily distinguished from the sub-odontoblast cells. In regions with open tubules, the odontoblasts were in stratified or pseudo-stratified in arrangement. Differences in structural antibody expression suggest a previously unreported heterogeneity of the odontoblast population and variations in different regions of the OP. This combined with differences in OPs extension and pulp cellular arrangement in worn and unworn regions suggests active and dynamic cellular responses to the opening of dentinal tubules by tooth wear.
Objectives:
Fundamental knowledge of cell organisation, function and regulation provides essentia... more Objectives: Fundamental knowledge of cell organisation, function and regulation provides essential underpinning for therapies to preserve pulp health, regenerate injured pulp tissues, and manage conditions from dentine sensitivity to tooth wear. This study applied contemporary immunohistochemical methods to investigate complex structural and functional interrelationships between odontoblast and sub-odontoblast cell layers (OCL and SOCL) in the rat incisor. Methods: Pulp tissues were surgically extracted, fixed in 4% paraformaldehyde, demineralized, and prepared for standard immunohistochemistry. Antibodies to vimentin, α actin, NaKATPase, and PGP 9.5, were used followed by alexafluor 488 and 594, and then examined using fluorescent-confocal microscopy. Results: Novel observations include evidence that the rat odontoblast presents in stratified or pseudo-stratified arrangement, rather than simple columnar formation. Additional cell types were identified within the OCL, many in distal locations presenting a stellate form and staining positive to αactin. A rich vascular network of small arterioles was also noted, with capillary networks located near the mineralizing front. Cells in the SOCL showed complex structure, with areas of high cellular density, composed of cells with large nuclei and sparse cytoplasm. These cells showed intense NaKATPase immunoreactivity, with some extending processes towards and into the OCL, whilst other processes remained within the SOCL. No processes where seen to enter to the diffuse cell layer of the bulk of the pulp. In keeping with other studies, no nerves were found in the OCL and SOCL. Conclusion: The OCL demonstrates structural heterogeneity and complexity, the functions of which are not known. SOCL has similar complexity, with networks of processes which extend into the OCL suggesting hitherto unrecognised functional connectivity. Lateral processes may further suggest cell-to-cell communication within the layer. Intense immunoreactivity to NaKATPase suggests functional specification and high degree of activity. The potential relevance of these structural-functional relationships will be discussed. Acknowledgements and/or Funding Source: Iraqi Ministry of Higher Education and Scientific Research.
European archives of paediatric dentistry : official journal of the European Academy of Paediatric Dentistry, Jan 18, 2015
In November 2014, a review of literature concerning prevalence data of Molar Incisor Hypominerali... more In November 2014, a review of literature concerning prevalence data of Molar Incisor Hypomineralisation (MIH) and Hypomineralised Second Primary Molars (HSPM) was performed. A search of PubMed online databases was conducted for relevant articles published until November 2014. The reference lists of all retrieved articles were hand-searched. Studies were included after assessing the eligibility of the full-text article. Out of 1078 manuscripts, a total of 157 English written publications were selected based on title and abstract. Of these 157, 60 were included in the study and allocated as 52 MIH and 5 HSPM, and 3 for both MIH and HSPM. These studies utilised the European Academy of Paediatric Dentistry judgment criteria, the modified index of developmental defects of enamel (mDDE) and self-devised criteria, and demonstrated a wide variation in the reported prevalence (MIH 2.9-44 %; HSPM 0-21.8 %). Most values mentioned were representative for specific areas. More studies were perfor...
A B S T R A C T The arrangement and roles of the odontoblast and its process in sensing and respo... more A B S T R A C T The arrangement and roles of the odontoblast and its process in sensing and responding to injuries such as tooth wear are incompletely understood. Evidence is presented that dentine exposure by tooth wear triggers structural and functional changes that aim to maintain tooth integrity. Mandibular first molars from freshly culled 8 week Wistar rats were prepared for light microscopy ground-sections (n = 6), or fixed in 4% paraformaldehyde, decalcified in 17% EDTA, sectioned and stained with antibodies to cyto-skeletal proteins (vimentin (vim), a-tubulin (tub) and a-actin), cellular homeostatic elements (sodium potassium ATPase (NaK-ATPase) and sodium hydrogen exchanger (NHE-1)), and sensory nerve fibres (CGRP) (n = 10) for fluorescence microscopy of worn and unworn regions of the mesial cusp. Immunoreactivity (IR) to vim, actin, NaK-ATPase and CGRP was confined to the pulpal third of odontoblast processes (OPs). IR to tub and nhe-1 was expressed by OPs in full dentine thickness. In areas associated with dentine exposure, the tubules contained no OPs. In regions with intact dentine, odontoblasts were arranged in a single cell layer and easily distinguished from the sub-odontoblast cells. In regions with open tubules, the odontoblasts were in stratified or pseudo-stratified in arrangement. Differences in structural antibody expression suggest a previously unreported heterogeneity of the odontoblast population and variations in different regions of the OP. This combined with differences in OPs extension and pulp cellular arrangement in worn and unworn regions suggests active and dynamic cellular responses to the opening of dentinal tubules by tooth wear.
Objectives:
Fundamental knowledge of cell organisation, function and regulation provides essentia... more Objectives: Fundamental knowledge of cell organisation, function and regulation provides essential underpinning for therapies to preserve pulp health, regenerate injured pulp tissues, and manage conditions from dentine sensitivity to tooth wear. This study applied contemporary immunohistochemical methods to investigate complex structural and functional interrelationships between odontoblast and sub-odontoblast cell layers (OCL and SOCL) in the rat incisor. Methods: Pulp tissues were surgically extracted, fixed in 4% paraformaldehyde, demineralized, and prepared for standard immunohistochemistry. Antibodies to vimentin, α actin, NaKATPase, and PGP 9.5, were used followed by alexafluor 488 and 594, and then examined using fluorescent-confocal microscopy. Results: Novel observations include evidence that the rat odontoblast presents in stratified or pseudo-stratified arrangement, rather than simple columnar formation. Additional cell types were identified within the OCL, many in distal locations presenting a stellate form and staining positive to αactin. A rich vascular network of small arterioles was also noted, with capillary networks located near the mineralizing front. Cells in the SOCL showed complex structure, with areas of high cellular density, composed of cells with large nuclei and sparse cytoplasm. These cells showed intense NaKATPase immunoreactivity, with some extending processes towards and into the OCL, whilst other processes remained within the SOCL. No processes where seen to enter to the diffuse cell layer of the bulk of the pulp. In keeping with other studies, no nerves were found in the OCL and SOCL. Conclusion: The OCL demonstrates structural heterogeneity and complexity, the functions of which are not known. SOCL has similar complexity, with networks of processes which extend into the OCL suggesting hitherto unrecognised functional connectivity. Lateral processes may further suggest cell-to-cell communication within the layer. Intense immunoreactivity to NaKATPase suggests functional specification and high degree of activity. The potential relevance of these structural-functional relationships will be discussed. Acknowledgements and/or Funding Source: Iraqi Ministry of Higher Education and Scientific Research.
Uploads
Papers by Dr-Ahmed Alhelal
Fundamental knowledge of cell organisation, function and regulation provides essential underpinning for therapies to preserve pulp health, regenerate injured pulp tissues, and manage conditions from dentine sensitivity to tooth wear. This study applied contemporary immunohistochemical methods to investigate complex structural and functional interrelationships between odontoblast and sub-odontoblast cell layers (OCL and SOCL) in the rat incisor.
Methods:
Pulp tissues were surgically extracted, fixed in 4% paraformaldehyde, demineralized, and prepared for standard immunohistochemistry. Antibodies to vimentin, α actin, NaKATPase, and PGP 9.5, were used followed by alexafluor 488 and 594, and then examined using fluorescent-confocal microscopy.
Results:
Novel observations include evidence that the rat odontoblast presents in stratified or pseudo-stratified arrangement, rather than simple columnar formation. Additional cell types were identified within the OCL, many in distal locations presenting a stellate form and staining positive to αactin. A rich vascular network of small arterioles was also noted, with capillary networks located near the mineralizing front.
Cells in the SOCL showed complex structure, with areas of high cellular density, composed of cells with large nuclei and sparse cytoplasm. These cells showed intense NaKATPase immunoreactivity, with some extending processes towards and into the OCL, whilst other processes remained within the SOCL. No processes where seen to enter to the diffuse cell layer of the bulk of the pulp. In keeping with other studies, no nerves were found in the OCL and SOCL.
Conclusion:
The OCL demonstrates structural heterogeneity and complexity, the functions of which are not known.
SOCL has similar complexity, with networks of processes which extend into the OCL suggesting hitherto unrecognised functional connectivity. Lateral processes may further suggest cell-to-cell communication within the layer. Intense immunoreactivity to NaKATPase suggests functional specification and high degree of activity.
The potential relevance of these structural-functional relationships will be discussed.
Acknowledgements and/or Funding Source:
Iraqi Ministry of Higher Education and Scientific Research.
Fundamental knowledge of cell organisation, function and regulation provides essential underpinning for therapies to preserve pulp health, regenerate injured pulp tissues, and manage conditions from dentine sensitivity to tooth wear. This study applied contemporary immunohistochemical methods to investigate complex structural and functional interrelationships between odontoblast and sub-odontoblast cell layers (OCL and SOCL) in the rat incisor.
Methods:
Pulp tissues were surgically extracted, fixed in 4% paraformaldehyde, demineralized, and prepared for standard immunohistochemistry. Antibodies to vimentin, α actin, NaKATPase, and PGP 9.5, were used followed by alexafluor 488 and 594, and then examined using fluorescent-confocal microscopy.
Results:
Novel observations include evidence that the rat odontoblast presents in stratified or pseudo-stratified arrangement, rather than simple columnar formation. Additional cell types were identified within the OCL, many in distal locations presenting a stellate form and staining positive to αactin. A rich vascular network of small arterioles was also noted, with capillary networks located near the mineralizing front.
Cells in the SOCL showed complex structure, with areas of high cellular density, composed of cells with large nuclei and sparse cytoplasm. These cells showed intense NaKATPase immunoreactivity, with some extending processes towards and into the OCL, whilst other processes remained within the SOCL. No processes where seen to enter to the diffuse cell layer of the bulk of the pulp. In keeping with other studies, no nerves were found in the OCL and SOCL.
Conclusion:
The OCL demonstrates structural heterogeneity and complexity, the functions of which are not known.
SOCL has similar complexity, with networks of processes which extend into the OCL suggesting hitherto unrecognised functional connectivity. Lateral processes may further suggest cell-to-cell communication within the layer. Intense immunoreactivity to NaKATPase suggests functional specification and high degree of activity.
The potential relevance of these structural-functional relationships will be discussed.
Acknowledgements and/or Funding Source:
Iraqi Ministry of Higher Education and Scientific Research.