| 1. |
- Danared, Håkan, et al.
(author)
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Preface
- 2017
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In: IPAC 2018 : Proceedings of the 8th International Particle Accelerator Conference - Proceedings of the 8th International Particle Accelerator Conference. - 9783954501823
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Journal article (other academic/artistic)
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| 2. |
- Franke Stenport, Victoria, 1970, et al.
(author)
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Precipitation of Calcium Phosphates in the Presence of Collagen Type I on Four Different Bioactive Titanium Surfaces: an in Vitro Study.
- 2015
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In: Journal of oral & maxillofacial research. - : Stilus Optimus. - 2029-283X. ; 6:4
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Journal article (peer-reviewed)abstract
- To compare the properties of calcium phosphate precipitation on four different bioactive surface preparations and one control surface in the simulated body fluid model with added collagen type I.Blasted titanium discs were treated with four different surface modifications, alkali and heat, sodium fluoride, anodic oxidation and hydroxyapatite coating. The discs were divided into five groups where one group, the blasted, served as control. The discs were immersed in simulated body fluid and collagen for 24 h, 3 days, 1 week and 2 weeks and then analysed by optical interferometry, scanning electron microscopy/energy dispersive X-ray analysis and X-ray photoelectron spectroscopy.All surfaces show small precipitates after 3 days which with longer immersion times increase. After 2 weeks the surfaces were completely covered with precipitates, and Ca/P ratios were approximately 1.3, independently on surface preparation. The fluoridated discs showed significantly (P ≤ 0.05) higher degree of CaP after one week of immersion as compared to the other surface preparations. The collagen type I content increased with time, as reflected by increased nitrogen content.The results from this study indicate that a fluoridated titanium surface may favour precipitation of calcium phosphate in the presence of collagen type I, as compared to the other surface treatments of the present study.
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| 3. |
- Olander, Julia, 1984, et al.
(author)
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Implant-Supported Single Crowns with Titanium or Zirconia Abutments: A Retrospective Up-to-5-year Follow-up Study.
- 2022
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In: The International journal of prosthodontics. - : Quintessence Publishing. - 1942-4426 .- 0893-2174. ; 35:4, s. 387-395
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Journal article (peer-reviewed)abstract
- To compare the clinical outcomes of single implants with titanium (Ti) or zirconia (Zr) abutments after up to 5 years in function.This study was a retrospective analysis on single implants with screw-retained abutments (Zr or Ti) covered with porcelain veneer placed between 2011 and 2013 at one referral specialist clinic. Clinical data from patient records were collected from 132 patients and 174 implants. Technical complications such as fractures, chipping, and abutment screw loosening were registered. Radiographs were analyzed comparing both annual bone loss and accumulated bone loss at 5 years. In 57 patients with 85 implants, the values of accumulated bone loss at 5 years were compared to baseline.Technical complications occurred in 16 (9%) of the implants, most often during the first year. The following complications were found: fracture of the abutment (n = 1); loosening of the abutment screws (n = 5); and chipping of the porcelain veneer (n = 11). Ti abutments had more complications than Zr abutments (79%). Of all the implants, 45% had an annual bone loss ranging between 0.05 and 2.15 mm, and 59% had an accumulated bone loss at 5 years ranging between 0.05 and 4.25 mm. Zr abutments had a statistically significantly higher amount of yearly and accumulated bone loss at 5 years.Abutment material affected marginal bone loss. The Zr group displayed statistically more bone loss both yearly and after 5 years compared to the Ti group. Technical complications were not affected by abutment material but were affected by age of the patient.
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| 4. |
- Olander, Julia, 1984, et al.
(author)
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Inflammatory Gene Profile and Particle Presence in Peri-Implant Mucosa: a Pilot Study on 9 Patients
- 2023
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In: Jomr-Journal of Oral & Maxillofacial Research. - 2029-283X. ; 14:3
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Journal article (peer-reviewed)abstract
- Objectives: The purpose of this pilot study is to compare gene expression in mucosa around dental implants with zirconia abutment to titanium and investigate presence of particles in mucosa samples and on implant heads. Material and Methods: Ten patients with a single implant supported prosthesis connected to zirconia or titanium abutments were invited at the five-year control. A clinical examination and a survey on experience of function and appearance were conducted. A mucosa biopsy taken in close vicinity to the implant were analysed by real-time polymerase chain reaction (qPCR) and presence of particles in a scanning electron microscope/energy-dispersive X-ray spectroscope (SEM/EDX). Cytological smear samples were collected and analysed through inductively coupled plasma mass spectrometry (ICP-MS) to investigate presence of particles on implant heads. Results: In total, 9 patients participated in the study, five with titanium abutments and four with zirconia abutments. All patients were satisfied with function and aesthetics. Titanium and iron particles were detected in mucosa biopsies. The ICP -MS analysis demonstrated presence of zirconia and titanium. Several proinflammatory genes were upregulated in the zirconia abutment group. Conclusions: Around zirconia abutments a slight increase in proinflammatory response and amount of wear particles was seen as compared to titanium. Wear particles of titanium were present in all soft tissue samples, however zirconia particles only in the samples from implants heads/mucosa with zirconia abutments.
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| 5. |
- Olander, Julia, 1984
(author)
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On biological response and wear particles around oral implants and implant components
- 2023
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Doctoral thesis (other academic/artistic)abstract
- ABSTRACT Wear particles released from implant components are gaining interest in the dental literature. In orthopedic medicine, wear particles are known to cause bone loss around medical implants in an aseptic manner and several in vitro studies have shown proinflammatory responses to titanium particles. In dentistry and medicine, several materials are used for implant constructions, with a variation in material properties such as hardness and surface roughness. Theoretically, dissimilarity in material combination may cause aggravation as the materials wear. Due to aesthetical advantages, ceramic abutments made from zirconia are increasingly used in dentistry. Zirconia is harder than titanium, which could lead to more wear and particle release. It is unknow whether wear particles in tissues around dental implants cause peri-implant bone loss. This thesis investigates whether the combination of materials in dental implant constructions alters biological responses and release of wear particles. Specifically, the studies included in this thesis compare single implant crowns manufactured with two abutment materials regarding clinical outcomes (Study I), in vitro wear on two implant materials (Study II), inflammatory cell responses (Study III), gene expression and presence of particles in soft tissues (Study IV). In Study I, we retrospectively analyzed data from patients treated at a specialist clinic with implant-supported crowns manufactured with two abutment types – zirconia and titanium. These analyses focused on clinical outcome variables with respect to function up to five years after prosthetic placement. In Study II, we evaluated experimental dynamic loading to compare wear, corrosion, and wear particle generation when these two abutment materials were used to connect to two types of implant materials. In Study III, we investigated the proinflammatory response to human peripheral blood mononuclear cells (PBMCS) when exposed to two types of disc materials combined with two particle materials. In Study IV, we evaluated mucosa biopsies from patients with single implant supported crowns manufactured on two abutment materials, focusing on gene expression and presence of wear particles. The following conclusions were drawn from the thesis. Study I show that abutment material type was statistically significantly associated with amount of yearly bone loss and accumulated five-year bone loss in this cohort but did not affect occurrence of technical complications. Implants with zirconia abutment showed an increase in bone loss but a decrease in technical complications compared to titanium. However, limitations in this finding include small sample size and only slight differences in bone loss values, which may not be clinically relevant. Study II shows that all implants had signs of wear irrespective of abutment material. No clear difference was seen comparing material combinations. Particles were released from the implant-abutment junction and the internal connections harbored wear particles inside the implants. More particles were released when using zirconia abutments. Study III shows that titanium particles and discs generated a higher proinflammatory response compared to zirconia. Neutrophils reacted to zirconia particles by releasing neutrophilic extracellular traps (NETs), which was not seen when exposed to titanium particles. In Study IV, we found titanium wear particles in soft tissue samples and zirconia particles on implant heads. More particles were found in mucosa around zirconia abutments. Gene expression showed upregulation of several proinflammatory genes when using zirconia abutment compared to titanium abutment. Wear particles may trigger pro-inflammatory reactions in the peri-implant mucosa.
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| 6. |
- Olander, Julia, 1984, et al.
(author)
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Wear particle release at the interface of dental implant components: Effects of different material combinations. An in vitro study
- 2022
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In: Dental Materials. - : Elsevier BV. - 0109-5641. ; 38:3, s. 508-516
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Journal article (peer-reviewed)abstract
- Objectives: Particle generation from implant components caused by frictional wear affect the surrounding peri-implant tissues. The objective of this study was to evaluate the effect of combining implant and abutment materials on wear and particle release in a dynamical loading setup. Methods: A customized dynamical loading machine was used to subject two implant materials (Titanium and Titanium- Zirconium alloy) paired with two different abutment materials (Titanium and Zirconia) to a cyclic loading set of 240.000 cycles (simulating 1 year of clinical use). The implant and abutment complex was immersed in corrosive liquid to collect particle debris and measure the release of corroded ions. Scanning electron microscopy was used to analyze signs of wear on the components after testing and evaluate the size and composition of particle debris. Results: Wear signs were evident in all material couplings. Particle debris was found on top, inside the implants, and on the abutment heads. The particle size ranged between 0.6 and 16.9 µm, with larger particles composed of Ti. Smaller-sized particles were found in the container liquid ranging from 0.253 to 1.7 µm compared to inside the implants ranging from 3.25 to 95.3 µm. Larger particles were found inside Tizr implants compared to Ti implants. Low levels of ions released due to corrosion were found when measuring content in surrounding liquid. Significance: Particle generation is evident when subjecting dental implant and abutment couplings in a dynamic loading setup. Internally connected implants hinder the release of larger particles to surrounding container liquid. © 2022 The Authors
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