| 1. |
- Höfner, S., et al.
(författare)
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Thermophysics of fractures on comet 67P/Churyumov-Gerasimenko
- 2017
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 608
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Tidskriftsartikel (refereegranskat)abstract
- Context. The camera OSIRIS on board Rosetta obtained high-resolution images of the nucleus of comet 67P/Churyumov-Gerasimenko (67P). Great parts of the nucleus surface are composed of fractured terrain.Aims. Fracture formation, evolution, and their potential relationship to physical processes that drive activity are not yet fully understood. Observed temperatures and gas production rates can be explained or interpreted with the presence of fractures by applying appropriate modelling methods.Methods. We followed a transient thermophysical model approach that includes radiative, conductive, and water-ice sublimation fluxes by considering a variety of heliocentric distances, illumination conditions, and thermophysical properties for a set of characteristic fracture geometries on the nucleus of 67P. We computed diurnal temperatures, heat fluxes, and outgassing behaviour in order to derive and distinguish the influence of the mentioned parameters on fractured terrain.Results. Our analysis confirms that fractures, as already indicated by former studies about concavities, deviate from flat-terrain topographies with equivalent properties, mostly through the effect of self-heating. Compared to flat terrain, illuminated cometary fractures are generally warmer, with smaller diurnal temperature fluctuations. Maximum sublimation rates reach higher peaks, and dust mantle quenching effects on sublimation rates are weaker. Consequently, the rough structure of the fractured terrain leads to significantly higher inferred surface thermal inertia values than for flat areas with identical physical properties, which might explain the range of measured thermal inertia on 67P.Conclusions. At 3.5 AU heliocentric distance, sublimation heat sinks in fractures converge to maximum values >50 W / m2 and trigger dust activity that can be related mainly to H2O. Fractures are likely to grow through the erosive interplay of alternating sublimation and thermal fatigue.
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| 2. |
- Berglundh, Tord, 1954, et al.
(författare)
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Peri-implant diseases and conditions: Consensus report of workgroup 4 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions
- 2018
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Ingår i: J Clin Periodontol. - : Wiley. - 0303-6979 .- 1600-051X. ; 45
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Tidskriftsartikel (refereegranskat)abstract
- A classification for peri-implant diseases and conditions was presented. Focused questions on the characteristics of peri-implant health, peri-implant mucositis, peri-implantitis, and soft- and hard-tissue deficiencies were addressed. Peri-implant health is characterized by the absence of erythema, bleeding on probing, swelling, and suppuration. It is not possible to define a range of probing depths compatible with health; Peri-implant health can exist around implants with reduced bone support. The main clinical characteristic of peri-implant mucositis is bleeding on gentle probing. Erythema, swelling, and/or suppuration may also be present. An increase in probing depth is often observed in the presence of peri-implant mucositis due to swelling or decrease in probing resistance. There is strong evidence from animal and human experimental studies that plaque is the etiological factor for peri-implant mucositis. Peri-implantitis is a plaque-associated pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant mucosa and subsequent progressive loss of supporting bone. Peri-implantitis sites exhibit clinical signs of inflammation, bleeding on probing, and/or suppuration, increased probing depths and/or recession of the mucosal margin in addition to radiographic bone loss. The evidence is equivocal regarding the effect of keratinized mucosa on the long-term health of the peri-implant tissue. It appears, however, that keratinized mucosa may have advantages regarding patient comfort and ease of plaque removal. Case definitions in day-to-day clinical practice and in epidemiological or disease-surveillance studies for peri-implant health, peri-implant mucositis, and peri-implantitis were introduced. The proposed case definitions should be viewed within the context that there is no generic implant and that there are numerous implant designs with different surface characteristics, surgical and loading protocols. It is recommended that the clinician obtain baseline radiographic and probing measurements following the completion of the implant-supported prosthesis.
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| 3. |
- Berglundh, Tord, 1954, et al.
(författare)
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Peri-implant diseases and conditions: Consensus report of workgroup 4 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions
- 2018
-
Ingår i: Journal of Periodontology. - : Wiley. - 0022-3492. ; 89
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Tidskriftsartikel (refereegranskat)abstract
- A classification for peri-implant diseases and conditions was presented. Focused questions on the characteristics of peri-implant health, peri-implant mucositis, peri-implantitis, and soft- and hard-tissue deficiencies were addressed. Peri-implant health is characterized by the absence of erythema, bleeding on probing, swelling, and suppuration. It is not possible to define a range of probing depths compatible with health; Peri-implant health can exist around implants with reduced bone support. The main clinical characteristic of peri-implant mucositis is bleeding on gentle probing. Erythema, swelling, and/or suppuration may also be present. An increase in probing depth is often observed in the presence of peri-implant mucositis due to swelling or decrease in probing resistance. There is strong evidence from animal and human experimental studies that plaque is the etiological factor for peri-implant mucositis. Peri-implantitis is a plaque-associated pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant mucosa and subsequent progressive loss of supporting bone. Peri-implantitis sites exhibit clinical signs of inflammation, bleeding on probing, and/or suppuration, increased probing depths and/or recession of the mucosal margin in addition to radiographic bone loss. The evidence is equivocal regarding the effect of keratinized mucosa on the long-term health of the peri-implant tissue. It appears, however, that keratinized mucosa may have advantages regarding patient comfort and ease of plaque removal. Case definitions in day-to-day clinical practice and in epidemiological or disease-surveillance studies for peri-implant health, peri-implant mucositis, and peri-implantitis were introduced. The proposed case definitions should be viewed within the context that there is no generic implant and that there are numerous implant designs with different surface characteristics, surgical and loading protocols. It is recommended that the clinician obtain baseline radiographic and probing measurements following the completion of the implant-supported prosthesis.
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| 4. |
- Dionigi, Carlotta, et al.
(författare)
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Cellular expression of epigenetic markers and oxidative stress in periodontitis lesions of smokers and non-smokers
- 2022
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Ingår i: Journal of Periodontal Research. - : Wiley. - 0022-3484 .- 1600-0765. ; 57:5, s. 952-959
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Tidskriftsartikel (refereegranskat)abstract
- Objective To evaluate differences in the cellular expression of epigenetic markers and oxidative stress in periodontitis lesions between current smokers and non-smokers. Background Tobacco smoking is recognized as one of the major risk factors for periodontitis. However, the mechanisms by which smoking affects the progression of the disease remain to be determined. Methods Twenty-five current smokers and 21 non-smokers with generalized severe periodontitis were included. From each patient, one soft tissue biopsy from a periodontitis site was harvested and prepared for histological analysis. The infiltrated connective tissue (ICT) was selected as the region of interest to assess the cellular expression of epigenetic markers and reactive oxygen/nitrogen species (RONS) by immunohistochemistry. Results Although the ICT of smokers and non-smokers did not differ in size or in the expression of markers for DNA damage or oxidative stress, current smokers presented with significantly lower area proportions and densities of cells positive for the epigenetic markers DNMT1 and AcH3. In addition, periodontitis lesions in current smokers presented with a diminished antimicrobial activity, as indicated by significantly lower densities and area proportions of NOX2- and iNOS-positive cells. Conclusions Components of the host response and epigenetic mechanisms in periodontitis lesions in smokers are downregulated as opposed to lesions of non-smokers.
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| 5. |
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| 6. |
- Lindhe, Jan, et al.
(författare)
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Peri-implant diseases : consensus report of the Sixth European Workshop on Periodontology.
- 2008
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Ingår i: Journal of Clinical Periodontology. - 0303-6979 .- 1600-051X. ; 35:8 Suppl, s. 282-285
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Tidskriftsartikel (refereegranskat)abstract
- Issues related to peri-implant disease were discussed. It was observed that the most common lesions that occur, i.e. peri-implant mucositis and peri-implantitis are caused by bacteria. While the lesion of peri-implant mucositis resides in the soft tissues, peri-implantitis also affects the supporting bone. Peri-implant mucositis occurs in about 80% of subjects (50% of sites) restored with implants, and peri-implantitis in between 28% and 56% of subjects (12-40% of sites). A number of risk indicators were identified including (i) poor oral hygiene, (ii) a history of periodontitis, (iii) diabetes and (iv) smoking. It was concluded that the treatment of peri-implant disease must include anti-infective measures. With respect to peri-implant mucositis, it appeared that non-surgical mechanical therapy caused the reduction in inflammation (bleeding on probing) but also that the adjunctive use of antimicrobial mouthrinses had a positive effect. It was agreed that the outcome of non-surgical treatment of peri-implantitis was unpredictable. The primary objective of surgical treatment in peri-implantitis is to get access to the implant surface for debridement and decontamination in order to achieve resolution of the inflammatory lesion. There was limited evidence that such treatment with the adjunctive use of systemic antibiotics could resolve a number of peri-implantitis lesions. There was no evidence that so-called regenerative procedures had additional beneficial effects on treatment outcome.
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| 7. |
- Lindhe, Jan, et al.
(författare)
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Peri-implant diseases : consensus report of the Sixth European Workshop on Periodontology.
- 2008
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Ingår i: Journal of Clinical Periodontology. - : Blackwell Munksgaard. - 0303-6979 .- 1600-051X. ; 35:8 Suppl, s. 282-285
-
Tidskriftsartikel (refereegranskat)abstract
- Issues related to peri-implant disease were discussed. It was observed that the most common lesions that occur, i.e. peri-implant mucositis and peri-implantitis are caused by bacteria. While the lesion of peri-implant mucositis resides in the soft tissues, peri-implantitis also affects the supporting bone. Peri-implant mucositis occurs in about 80% of subjects (50% of sites) restored with implants, and peri-implantitis in between 28% and 56% of subjects (12-40% of sites). A number of risk indicators were identified including (i) poor oral hygiene, (ii) a history of periodontitis, (iii) diabetes and (iv) smoking. It was concluded that the treatment of peri-implant disease must include anti-infective measures. With respect to peri-implant mucositis, it appeared that non-surgical mechanical therapy caused the reduction in inflammation (bleeding on probing) but also that the adjunctive use of antimicrobial mouthrinses had a positive effect. It was agreed that the outcome of non-surgical treatment of peri-implantitis was unpredictable. The primary objective of surgical treatment in peri-implantitis is to get access to the implant surface for debridement and decontamination in order to achieve resolution of the inflammatory lesion. There was limited evidence that such treatment with the adjunctive use of systemic antibiotics could resolve a number of peri-implantitis lesions. There was no evidence that so-called regenerative procedures had additional beneficial effects on treatment outcome.
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| 8. |
- Schmidt, J. C., et al.
(författare)
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Periodontitis lesions in smokers and non-smokers
- 2020
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Ingår i: European Journal of Oral Sciences. - : Wiley. - 0909-8836 .- 1600-0722. ; 128:3, s. 196-203
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Tidskriftsartikel (refereegranskat)abstract
- Differences in the progression of periodontitis have been observed between smokers and non-smokers. The aim of the present study was to compare vascular and inflammatory cell densities in periodontitis lesions from smokers and non-smokers to gain further understanding of the influence of smoking on histopathological characteristics of the disease. Two groups of patients with generalized severe periodontitis were recruited. One group consisted of 25 current smokers, aged 33-69 yr, while the second group comprised 21 non-smokers, aged 35-76 yr. From each patient, gingival biopsies were harvested from one periodontitis site (probing pocket depth >= 6 mm and bleeding on probing) and one site without clinical signs of gingival inflammation (reference site). Immunohistochemical analyses were performed to assess the density of vessels and inflammatory cells. Small differences existed between smokers and non-smokers regarding the size, proportion, number, and density of cells in periodontitis lesions. However, the vascular density in periodontitis lesions was significantly higher in non-smokers than in smokers. In clinically healthy reference sites, lesions were considerably smaller than in periodontitis sites and presented with similar vascular densities in smokers and non-smokers.
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