| 1. |
- Divaris, K., et al.
(författare)
-
Phenotype Harmonization in the GLIDE2 Oral Health Genomics Consortium
- 2022
-
Ingår i: Journal of Dental Research. - : Sage Publications. - 0022-0345 .- 1544-0591. ; 101:11, s. 1408-1416
-
Tidskriftsartikel (refereegranskat)abstract
- Genetic risk factors play important roles in the etiology of oral, dental, and craniofacial diseases. Identifying the relevant risk loci and understanding their molecular biology could highlight new prevention and management avenues. Our current understanding of oral health genomics suggests that dental caries and periodontitis are polygenic diseases, and very large sample sizes and informative phenotypic measures are required to discover signals and adequately map associations across the human genome. In this article, we introduce the second wave of the Gene-Lifestyle Interactions and Dental Endpoints consortium (GLIDE2) and discuss relevant data analytics challenges, opportunities, and applications. In this phase, the consortium comprises a diverse, multiethnic sample of over 700,000 participants from 21 studies contributing clinical data on dental caries experience and periodontitis. We outline the methodological challenges of combining data from heterogeneous populations, as well as the data reduction problem in resolving detailed clinical examination records into tractable phenotypes, and describe a strategy that addresses this. Specifically, we propose a 3-tiered phenotyping approach aimed at leveraging both the large sample size in the consortium and the detailed clinical information available in some studies, wherein binary, severity-encompassing, and “precision,” data-driven clinical traits are employed. As an illustration of the use of data-driven traits across multiple cohorts, we present an application of dental caries experience data harmonization in 8 participating studies (N = 55,143) using previously developed permanent dentition tooth surface–level dental caries pattern traits. We demonstrate that these clinical patterns are transferable across multiple cohorts, have similar relative contributions within each study, and thus are prime targets for genetic interrogation in the expanded and diverse multiethnic sample of GLIDE2. We anticipate that results from GLIDE2 will decisively advance the knowledge base of mechanisms at play in oral, dental, and craniofacial health and disease and further catalyze international collaboration and data and resource sharing in genomics research.
|
|
| 2. |
- Johansson, Sveneric, et al.
(författare)
-
The FERRUM Project: New f-value Data for Fe II and Astrophysical Applications
- 2002
-
Ingår i: Physica Scripta. - : Institute of Physics Publishing (IOPP). - 0281-1847 .- 0031-8949 .- 1402-4896. ; T100, s. 71-80
-
Konferensbidrag (refereegranskat)abstract
- We present the FERRUM Project, an international collaboration aiming at a production and evaluation of oscillator strengths (transition probabilities) of selected spectral lines of singly ionized iron group elements, that are of astrophysical relevance. The results obtained include measurements and calculations of permitted and forbidden lines of Fe II. The data have been applied to both emission and absorption lines in astrophysical spectra. We make comparisons between experimental, theoretical and astrophysical f-values. We give a general review of the various measurements, and discuss the UV8 multiplet of Fe II around 1610 Šin detail.
|
|
| 3. |
- Johansson, C.B., et al.
(författare)
-
3.16 Histological Analysis
- 2017. - 2
-
Ingår i: Comprehensive Biomaterials II. - : Elsevier. - 9780081006924 ; , s. 335-363
-
Bokkapitel (refereegranskat)abstract
- All devices are recognized as foreign body materials once inserted in the living body, and they will all cause foreign body reactions. To determine the degree of integration, both qualitative and quantitative data are obtained by examining histological sections. This technique is the state of the art and has been so for decades. Quantitative analysis is important, but one cannot solely rely on data that computer programs rather rapidly generate. The qualitative examinations are of utmost importance. Tissue which has been properly fixed, processed, and maintained in the laboratories can be used for a broad range of histological analysis. This chapter presents some qualitative and quantitative state-of-the-art techniques used in relation to bone tissue analyses around biomaterials. Methods are described from fixation of tissue, preparation of sections, routine and new techniques adjusted to state-of-the-art techniques, and some complementary techniques. The importance of investigating the tissue reactions in various levels, from light microscopic to molecular, such as the localization of proteins as well as some quantification methods will be presented. In the future, we foresee even more complementary techniques to obtain more information regarding this tissue.
|
|
| 4. |
- Jinno, Yohei, et al.
(författare)
-
Impact of salivary contamination during placement of implants with simultaneous bony augmentation in iliac bone in sheep
- 2019
-
Ingår i: British Journal of Oral & Maxillofacial Surgery. - : Elsevier. - 0266-4356 .- 1532-1940. ; 57:10, s. 1131-1136
-
Tidskriftsartikel (refereegranskat)abstract
- Our aim was to investigate the possible impact of contamination with saliva on osseointegration during placement of implants with simultaneous bone augmentation. Six hemispheric shape bone defects (8mm in diameter×4mm deep) were prepared in each iliac bone of six sheep. A dental implant (2.9mm in diameter×10mm long) was placed in the centre of each defect, and then pairs of defects were filled with one of the following bone augmentation materials: autogenous bone, autogenous bone plus bovine bone, or resorbable biphasic ceramic bone substitute. One site in each augmentation group was impregnated with saliva (contaminated group), while the other was not (non-contaminated group). Bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) within implant threads were measured after a healing period of five weeks, both in respect of the implant inserted in the augmented bone and in that inserted in the residual bone. Overall results showed that there was a significant difference between the contaminated and non-contaminated group for BIC in the augmented implant (p=0.028), while there were no significant differences in the implant in residual bone (p=0.722). For BAFO, there were no significant differences between the contaminated and non-contaminated groups among the different augmentation materials. The results showed that contamination with saliva during placement of an implant with simultaneous bone augmentation had a serious deleterious effect on osseointegration of the aspect of the implant within the augmented defect. Contamination with saliva during placement of an implant with simultaneous bone augmentation should therefore be avoided.
|
|
| 5. |
- Jinno, Yohei, et al.
(författare)
-
Impact of surface contamination of implants with saliva during placement in augmented bone defects in sheep calvaria.
- 2019
-
Ingår i: British Journal of Oral & Maxillofacial Surgery. - : Elsevier. - 0266-4356 .- 1532-1940. ; 57:1, s. 41-46
-
Tidskriftsartikel (refereegranskat)abstract
- Our aim was to try and find out whether contamination with saliva during insertion of dental implants affects osseointegration in bone that has been augmented with different grafts. Six bony defects were created in each of the calvaria of six sheep, and then augmented with three different materials (autogenous bone, bovine bone, and resorbable biphasic ceramic bone substitute) After five weeks of healing, three implants contaminated with saliva (contaminated group) and three not contaminated (uncontaminated group) were placed in the centre of the augmented areas. For histomorphometric analysis, bone implant contact, bone area fraction occupancy, bone and material area, and bony area were measured after a healing period of five weeks. There was a significant difference between the contaminated and uncontaminated groups (p=0.036) for bone implant contact only in the augmented areas, but there were no significant differences in bone area fraction occupancy, bone and material area, and bony area. We conclude that contamination with saliva during placement of dental implants can significantly compromise bone implant contact in augmented areas, but had no significant effect on the formation of bone in areas more distant from the surface of the implant. We suggest that salivary contamination should be avoided during placement of dental implants in augmented areas.
|
|
| 6. |
- Johansson, Krister, et al.
(författare)
-
Effects of Bacterial Contamination on Dental Implants During Surgery : A Systematic Review
- 2017
-
Ingår i: Implant Dentistry. - : Lippincott Williams & Wilkins. - 1056-6163 .- 1538-2982. ; 26:5, s. 778-789
-
Forskningsöversikt (refereegranskat)abstract
- INTRODUCTION: Contamination during surgery negatively influences the prognosis of orthopaedic implants; however, it has not been proven whether contamination influences the success of dental implant treatment. The aim of the systematic review was to investigate if there exists evidence in the literature whether contamination of dental implants during surgery affects osseointegration and clinical success. MATERIALS AND METHODS: Four data bases were used for the literature search. Primary studies and reviews regarding both clinical and preclinical research were eligible. Rating of the summarized quality of the evidence was performed. RESULTS: Five preclinical studies were included. Because of the estimated high risk of bias in all included studies and extensive differences in study design between the included studies, meta-analysis was not performed and no reliable aggregated data could be extracted. CONCLUSIONS: It is suggested that the scientific evidence with regard to the current topic is insufficient. Further controlled studies are warranted.
|
|
| 7. |
- Johansson, Krister, et al.
(författare)
-
Estimation of Blood Loss in Oral and Maxillofacial Surgery by Measurements of Low Haemoglobin Levels in Mixtures of Blood, Saliva and Saline : a Laboratory Study
- 2021
-
Ingår i: Journal of Oral & Maxillofacial Research. - : Stilus Optimus. - 2029-283X. ; 12:2
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: Estimating blood loss is an important factor in several surgical procedures. The accuracy of blood loss measurements in situations where blood is mixed with saliva and saline is however uncertain. The purpose of this laboratory study was to ascertain if blood loss measurements in mixtures of blood, saline, and saliva are reliable and could be applicable in a clinical setting.Material and Methods: Venous blood and resting saliva were collected from six volunteers. Saliva, saline, and combinations thereof were mixed with blood to obtain different concentrations. A portable spectrophotometer was first used to measure the haemoglobin concentration in undiluted venous blood followed by measurements of the haemoglobin concentration after each dilution. To examine the strength of linear relationships, linear regression and Pearson correlations were used.Results: The measurements of haemoglobin concentrations in mixtures of blood, saline, and saliva were proven to be accurate for haemoglobin measurements > 0.3 g/dl (correlation = 0.986 to 1). For haemoglobin measurements < 0.3 g/dl, a small increase in haemoglobin values were reported, which was directly associated to the saliva concentration in the solution (correlation = 0.983 to 1). This interference of saliva was significantly eliminated by diluting the samples with saline, mimicking the clinical situation.Conclusions: The results suggest that a portable spectrophotometer can be used clinically to preoperatively measure the haemoglobin value of a venous blood sample and postoperatively measure the haemoglobin value of the collected liquids, including shed blood, thereby achieving a highly accurate method of measuring blood loss during oral and maxillofacial surgery.
|
|
| 8. |
|
|
| 9. |
- Johansson, Pär, et al.
(författare)
-
Biomechanical, histological, and computed X-ray tomographic analyses of hydroxyapatite coated PEEK implants in an extended healing model in rabbit
- 2018
-
Ingår i: Journal of Biomedical Materials Research Part A. - : Wiley. - 1549-3296 .- 1552-4965. ; 106:5, s. 1440-1447
-
Tidskriftsartikel (refereegranskat)abstract
- A nanosized hydroxyapatite (HA) modification on polyetheretherketone (PEEK) using a novel spin coating technique was investigated in a rabbit model. Spin coating technique creates a 20-40 nm thick layer of nanosized HA particles with similar shape, size, and crystallinity as human bone. Some implants were designed with a perforating hole in the apical region to mimic a fusion chamber of a spinal implant. The coating nano-structures were assessed using a scanning electron microscope. The in vivo response to HA-PEEK was compared to untreated PEEK with respect to removal torque, histomorphometry, and computed microtomography. The HA-coated and pure PEEK implants were inserted in the tibia and femur bone according to simple randomization. The rabbits were sacrificed 20 weeks after implantation. Removal torque analysis showed significantly higher values for HA-PEEK. Qualitative histological evaluation revealed an intimate contact between PEEK and the bone at the threads and perforated hole. Histomorphometric assessment showed higher bone-implant and bone area values for HA-PEEK but without statistical significance. The effect of the HA coating showed most prominent effect in the removal torque which may be correlated to an alteration in the bone quality around the HA-PEEK implants. (c) 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1440-1447, 2018.
|
|
| 10. |
- Okhrimenko, Denis V., et al.
(författare)
-
Hydrolytic Stability of 3-Aminopropylsilane Coupling Agent on Silica and Silicate Surfaces at Elevated Temperatures
- 2017
-
Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 9:9, s. 8344-8353
-
Tidskriftsartikel (refereegranskat)abstract
- 3-Aminopropylsilane (APS) coupling agent is widely used in industrial, biomaterial, and medical applications to improve adhesion of polymers to inorganic materials. However, during exposure to elevated humidity and temperature, the deposited APS layers can decompose, leading to reduction in coupling efficiency, thus decreasing the product quality and the mechanical strength of the polymer–inorganic material interface. Therefore, a better understanding of the chemical state and stability of APS on inorganic surfaces is needed. In this work, we investigated APS adhesion on silica wafers and compared its properties with those on complex silicate surfaces such as those used by industry (mineral fibers and fiber melt wafers). The APS was deposited from aqueous and organic (toluene) solutions and studied with surface sensitive techniques, including X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), streaming potential, contact angle, and spectroscopic ellipsometry. APS configuration on a model silica surface at a range of coverages was simulated using density functional theory (DFT). We also studied the stability of adsorbed APS during aging at high humidity and elevated temperature. Our results demonstrated that APS layer formation depends on the choice of solvent and substrate used for deposition. On silica surfaces in toluene, APS formed unstable multilayers, while from aqueous solutions, thinner and more stable APS layers were produced. The chemical composition and substrate roughness influence the amount of deposited APS. More APS was deposited and its layers were more stable on fiber melt than on silica wafers. The changes in the amount of adsorbed APS can be successfully monitored by streaming potential. These results will aid in improving industrial- and laboratory-scale APS deposition methods and increasing adhesion and stability, thus increasing the quality and effectiveness of materials where APS is used as a coupling agent.
|
|
