| 1. |
- Al-Asfour, Adel, et al.
(författare)
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Host tissue reactions of non-demineralized autogenic and xenogenic dentin blocks implanted in a non-osteogenic environment. An experimental study in rabbits.
- 2014
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Ingår i: Dental traumatology : official publication of International Association for Dental Traumatology. - : Wiley. - 1600-9657. ; 30:3, s. 198-203
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Tidskriftsartikel (refereegranskat)abstract
- Dentoalveolar ankylosis with osseous replacement is often seen after replantation of avulsed teeth, and this process may be used for preservation of alveolar crests after trauma. Its exact mechanisms with regard to osteoinductive properties are not yet fully understood and need to be systematically investigated. Dentin can possibly act as a slow-releasing carrier of bone morphogenic proteins (BMP), and this property of dentin has been proposed to be used as an alternative or supplement to bone grafting in the maxillofacial region. We aimed to initially asses host tissue reactions to dentin by implanting dentin blocks of autogenic and xenogenic human origin in rabbit connective tissue of the abdominal wall and femoral muscle. Animals were sacrificed after a period of 3months, and histological processing, sectioning and examinations were carried out. Bone formation, cell counts and thickness of capsule surrounding the grafts were evaluated. Only minor signs of heterotopic bone formation were seen. There were no significant differences between autografts and xenografts or grafts implanted in connective tissue or muscle with regards to tissue reactions except for a significant difference (P=0.018) in findings of more local inflammatory cells in relation to grafts placed in connective tissue in the autograft group. We conclude that during the time frame of this study, non-demineralized dentin, whether autogenous or xenogenic did not have the potential to induce bone formation when implanted in non-osteogenic areas such as the abdominal wall and abdominal muscle of rabbits.
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| 2. |
- Maslamani, Manal, et al.
(författare)
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Effect of periodontal ligament removal with gauze prior to delayed replantation in rabbit incisors on rate of replacement resorption
- 2018
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Ingår i: Dental Traumatology. - : John Wiley & Sons. - 1600-4469 .- 1600-9657. ; 34:3, s. 182-187
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Tidskriftsartikel (refereegranskat)abstract
- Background/AimDelayed (dry storage > 60minutes) replantation results in ankylosis and replacement resorption. It has been suggested to remove the non-viable periodontal ligament before replantation to possibly reduce the rate of replacement resorption. However there has been no study on the rate of replacement resorption after such measures. The aim of this study was to investigate if there was any difference in the rate of replacement resorption by either removing the periodontal ligament (PDL) with gauze or not removing PDL in teeth subjected to delayed replantation followed by healing for 2 or 6weeks. Materials and MethodsMaxillary central incisors were extracted in 8 rabbits. In the right central incisors, the necrotic PDL was removed by dry gauze over the root surface. In the left eight extracted teeth PDL was left on the root surface. All extracted teeth were left to dry for 60minutes. Extra-oral root canal treatment was performed before replantation. The rabbits were sacrificed after 2weeks and 6weeks respectively. Histologic processing and evaluation was done. ResultsIn the 2weeks group, all teeth showed ankylosis. The cementum was intact, and fusion of the bone and root was generally seen without resorption of the root, whereas in the 6weeks group regardless of whether PDL had been kept or not, ankylosis and osseous replacement of the dentin was seen. There was no evidence of inflammatory infiltrate in the sections examined. ConclusionRemoval of PDL prior to delayed replantation may result in some initial protection of the cementum during the first few weeks. However, over longer times there seems to be neither protection of the dentin from ankylosis and osseous replacement, nor any influence on the rate of replacement resorption.
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| 3. |
- Mikryukov, Vladimir, et al.
(författare)
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Connecting the multiple dimensions of global soil fungal diversity
- 2023
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Ingår i: Science advances. - 2375-2548. ; 9:48
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Tidskriftsartikel (refereegranskat)abstract
- How the multiple facets of soil fungal diversity vary worldwide remains virtually unknown, hindering the management of this essential species-rich group. By sequencing high-resolution DNA markers in over 4000 topsoil samples from natural and human-altered ecosystems across all continents, we illustrate the distributions and drivers of different levels of taxonomic and phylogenetic diversity of fungi and their ecological groups. We show the impact of precipitation and temperature interactions on local fungal species richness (alpha diversity) across different climates. Our findings reveal how temperature drives fungal compositional turnover (beta diversity) and phylogenetic diversity, linking them with regional species richness (gamma diversity). We integrate fungi into the principles of global biodiversity distribution and present detailed maps for biodiversity conservation and modeling of global ecological processes.
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| 4. |
- Tedersoo, Leho, et al.
(författare)
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Global patterns in endemicity and vulnerability of soil fungi.
- 2022
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Ingår i: Global change biology. - : Wiley. - 1365-2486 .- 1354-1013. ; 28:22, s. 6696-6710
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Tidskriftsartikel (refereegranskat)abstract
- Fungi are highly diverse organisms, which provide multiple ecosystem services. However, compared with charismatic animals and plants, the distribution patterns and conservation needs of fungi have been little explored. Here, we examined endemicity patterns, global change vulnerability and conservation priority areas for functional groups of soil fungi based on six global surveys using a high-resolution, long-read metabarcoding approach. We found that the endemicity of all fungi and most functional groups peaks in tropical habitats, including Amazonia, Yucatan, West-Central Africa, Sri Lanka, and New Caledonia, with a negligible island effect compared with plants and animals. We also found that fungi are predominantly vulnerable to drought, heat and land-cover change, particularly in dry tropical regions with high human population density. Fungal conservation areas of highest priority include herbaceous wetlands, tropical forests, and woodlands. We stress that more attention should be focused on the conservation of fungi, especially root symbiotic arbuscular mycorrhizal and ectomycorrhizal fungi in tropical regions as well as unicellular early-diverging groups and macrofungi in general. Given the low overlap between the endemicity of fungi and macroorganisms, but high conservation needs in both groups, detailed analyses on distribution and conservation requirements are warranted for other microorganisms and soil organisms.
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