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Unosson, Erik
Publications (10 of 27) Show all publications
Berg, C., Unosson, E., Engqvist, H. & Xia, W. (2019). ACP-Mg particles for treatment of dental hypersensitivity: a mode of action study. In: : . Paper presented at Euromat 2019, 1-5 September 2019, Stockholm, Sweden.
Open this publication in new window or tab >>ACP-Mg particles for treatment of dental hypersensitivity: a mode of action study
2019 (English)Conference paper, Poster (with or without abstract) (Other academic)
Abstract [en]

Introduction/purpose:

Dental hypersensitivity is a common clinical condition usually associated with exposed dentinal tubules. Occlusion of those, hindering fluid movement as a response to external stimuli, is one approach to reduce pain.[1] The occluding agent should induce mineralization and have a good filling effect. In this study, particles (200-400 nm) of Amorphous Calcium Phosphate with Mg (ACP-Mg) were used aiming to evaluate the mode of action with in-vitro studies on dentine as well as degradation properties in buffered systems.

Methods:

Degradation properties and ion-release was monitored by dispersing the particles in Tris-HCl (10 mg/mL) storing the dispersions at 37 °C.  In-vitro testing was performed on 1 mm thick dentine discs cut from extracted human molars. Specimens were etched in 35 % phosphoric acid, rinsed with DI-water followed by treatment by applying a gel formulation containing the particles using a soft bristled toothbrush, brushing 1 min on each side and leaving the specimen to rest for 3 min. Treatment was repeated four times during one day and samples were incubated at 37 °C in artificial saliva.

Results:

In vitro tests and degradation studies showed that ACP-Mg particles induced formation of Hydroxyapatite (HA). ICP-OES, XRD and SEM showed that there was a rapid release of all ions up to 6 hours followed by a re-precipitation of HA at 24 hours with a lower Mg-content. The crystallinity increased with time as the concentration of all ions decreased in the solutions. Morphological evaluation for the in-vitro tests showed that HA-like structures formed already after 24 hours on the dentine surface.  Cross-sections revealed that the particles reached as far as 80 µm from the surface and tubules, fully occluded by HA-like structures, was visible at comparable depths after 7 days.

Conclusions:

ACP-Mg particles can be used to reduce dentine hypersensitivity by effective occlusion of dentine tubules via rapid formation of surface and intra-tubular HA.

References:

1. Splieth CH, Tachou A. 2013. Epidemiology of dentin hypersensitivity. Clin Oral Investig. 17:3–8. 

National Category
Engineering and Technology Medical Engineering
Identifiers
urn:nbn:se:uu:diva-398211 (URN)
Conference
Euromat 2019, 1-5 September 2019, Stockholm, Sweden
Available from: 2019-12-03 Created: 2019-12-03 Last updated: 2019-12-09Bibliographically approved
Janson, O., Unosson, E., Strömme, M., Engqvist, H. & Welch, K. (2017). Organic degradation potential of a TiO2/H2O2/UV-Vis system for dental applications. Journal of Dentistry, 67, 53-57
Open this publication in new window or tab >>Organic degradation potential of a TiO2/H2O2/UV-Vis system for dental applications
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2017 (English)In: Journal of Dentistry, ISSN 0300-5712, E-ISSN 1879-176X, Vol. 67, p. 53-57Article in journal (Refereed) Published
Abstract [en]

Objectives

The combination of TiO2 and H2O2 under light activation constitutes a promising method for disinfection of dental prosthetics and implants, due to production of reactive oxygen species (ROS). The aim of this work was to investigate the organic degradation ability of TiO2 particles in combination with H2O2 and under light activation utilizing the organic dye rhodamine B (RhB).

Methods

Five different types of TiO2 particles, consisting of anatase, rutile, or a mixture of these crystalline phases, were combined with H2O2 and RhB, and subsequently exposed to UV (365 nm) or visible (405 nm) light at an irradiance of 2.1 mW/cm2.

Results

It was found that rutile in combination with low concentrations of H2O2 (1.0–3.5 mM) resulted in a degradation of RhB of 96% and 77% after 10 min exposure to 365 nm and 405 nm light, respectively, which was the highest degradation of all test groups. Control measurements performed without light irradiation or irradiation at 470 nm, or without TiO2 particles resulted in little or no degradation of RhB.

Conclusions

Low H2O2 concentrations (1.0 mM–3.5 mM) and visible light (405 nm) used in combination with rutile TiO2 particles showed the highest RhB degradation capacity.

Clinical significance

A combination of TiO2 particles and H2O2 exposed to low energy UV or high energy visible light has an organic degradation capability that could be utilized in applications to kill or inactivate bacteria on medical devices such as dental implants for treatment against, e.g., peri-implantitis.

Keywords
TiO, HO, Reactive oxygen species, Rhodamine B, Rutile
National Category
Nano Technology
Research subject
Engineering Science with specialization in Nanotechnology and Functional Materials
Identifiers
urn:nbn:se:uu:diva-330202 (URN)10.1016/j.jdent.2017.09.001 (DOI)000417204800007 ()28886983 (PubMedID)
Funder
VINNOVA, E!8320
Available from: 2017-09-27 Created: 2017-09-27 Last updated: 2018-08-27Bibliographically approved
Unosson, E., Morgenstern, M., Engqvist, H. & Welch, K. (2016). In vitro antibacterial properties and UV induced response from Staphylococcus epidermidis on Ag/Ti oxide thin films. Journal of materials science. Materials in medicine, 27(3), Article ID 49.
Open this publication in new window or tab >>In vitro antibacterial properties and UV induced response from Staphylococcus epidermidis on Ag/Ti oxide thin films
2016 (English)In: Journal of materials science. Materials in medicine, ISSN 0957-4530, E-ISSN 1573-4838, Vol. 27, no 3, article id 49Article in journal (Refereed) Published
Abstract [en]

Implanted materials are susceptible to bacterial colonization and biofilm formation, which can result in severe infection and lost implant function. UV induced photocatalytic disinfection on TiO2 and release of Ag+ ions are two promising strategies to combat such events, and can be combined for improved efficiency. In the current study, a combinatorial physical vapor deposition technique was utilized to construct a gradient coating between Ag and Ti oxide, and the coating was evaluated for antibacterial properties in darkness and under UV light against Staphylococcus epidermidis. The findings revealed a potent antibacterial effect in darkness due to Ag+ release, with near full elimination (97%) of viable bacteria and visible cell lysis on Ag dominated surfaces. The photocatalytic activity, however, was demonstrated poor due to low TiO2 crystallinity, and UV light irradiation of the coating did not contribute to the antibacterial effect. On the contrary, bacterial viability was in several instances higher after UV illumination, proposing a UV induced SOS response from the bacteria that limited the reduction rate during Ag+ exposure. Such secondary effects should thus be considered in the development of multifunctional coatings that rely on UV activation. 

Keywords
Silver; Titanium; UV; Antibacterial; SOS response; S. epidermidis
National Category
Medical Materials Materials Engineering Nano Technology
Research subject
Engineering Science with specialization in Materials Science
Identifiers
urn:nbn:se:uu:diva-249179 (URN)10.1007/s10856-015-5662-5 (DOI)000368728100007 ()26758896 (PubMedID)
Projects
ProViking EBM
Funder
Swedish Foundation for Strategic Research
Available from: 2015-04-12 Created: 2015-04-12 Last updated: 2018-02-08Bibliographically approved
Fu, L., Unosson, E., Wu, C., Grandfield, K., Chang, J., Engqvist, H. & Xia, W. (2016). Spark plasma sintering consolidated transparent ZrO2- SiO2 glass ceramic containing nano-sized ZrO2 spheres. In: : . Paper presented at ICC6 International Congress on Ceramics.
Open this publication in new window or tab >>Spark plasma sintering consolidated transparent ZrO2- SiO2 glass ceramic containing nano-sized ZrO2 spheres
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2016 (English)Conference paper, Poster (with or without abstract) (Refereed)
National Category
Medical Materials
Identifiers
urn:nbn:se:uu:diva-284200 (URN)
External cooperation:
Conference
ICC6 International Congress on Ceramics
Available from: 2016-04-15 Created: 2016-04-15 Last updated: 2018-02-08
Fu, L., Wu, C., Grandfield, K., Unosson, E., Chang, J., Engqvist, H. & Xia, W. (2016). Transparent single crystalline ZrO2-SiO2 glass nanoceramic sintered by SPS. Journal of the European Ceramic Society, 36(14), 3487-3494
Open this publication in new window or tab >>Transparent single crystalline ZrO2-SiO2 glass nanoceramic sintered by SPS
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2016 (English)In: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 36, no 14, p. 3487-3494Article in journal (Refereed) Published
Abstract [en]

Transparent ZrO2-SiO2 glass ceramics show potential for application in the dental industry. The application of this material prepared by a sol-gel method was hindered by the difficulties in obtaining large dimension samples. Spark plasma sintering (SPS) offers the possibility of achieving transparent ZrO2-SiO2 glass ceramics. In this study, a ZrO2-SiO2 powder was prepared by the sol-gel method and subsequently sintered by SPS. Varied sintering temperatures and pressures were explored to achieve better mechanical strength and transparency. TEM results showed single crystalline ZrO2 spherical nanocrystals (approximately 20 nm) homogenously embedded in the SiO2 matrix. Tetragonal ZrO2 was the only crystalline phase in all specimens. With sintering conditions of 1200 degrees C and 30 MPa, a glass ceramic with fracture toughness of 4.13 MPa was obtained. This value is similar to the commercial dental glass ceramic of IPS e.max (R) Press. The studied transparent glass ceramic with high transparency and moderate mechanical strength shows promise for dental application.

Keywords
ZrO2-SiO2, Single crystalline spheres, Transparent glass ceramic, SPS, Sol-gel
National Category
Materials Engineering
Identifiers
urn:nbn:se:uu:diva-301007 (URN)10.1016/j.jeurceramsoc.2016.05.016 (DOI)000379888400029 ()
External cooperation:
Funder
Carl Tryggers foundation
Available from: 2016-08-17 Created: 2016-08-17 Last updated: 2018-08-12Bibliographically approved
Janson, O., Unosson, E., Engqvist, H. & Welch, K. (2015). Effects on organic degradation in the TiO2/H2O2/UV-Vis system. European Cells and Materials, 29, 20
Open this publication in new window or tab >>Effects on organic degradation in the TiO2/H2O2/UV-Vis system
2015 (English)In: European Cells and Materials, ISSN 1473-2262, E-ISSN 1473-2262, Vol. 29, p. 20-Article in journal (Refereed) Published
National Category
Materials Engineering
Research subject
Engineering Science with specialization in Materials Science; Engineering Science with specialization in Nanotechnology and Functional Materials
Identifiers
urn:nbn:se:uu:diva-264858 (URN)
Funder
VINNOVA
Available from: 2015-10-19 Created: 2015-10-19 Last updated: 2018-02-08
Janson, O., Unosson, E., Engqvist, H. & Welch, K. (2015). Effects on organic degradation in the TiO2/H2O2/UV-Vis system. In: 8th Annual meeting of the Scandinavian Society for Biomaterials Proceeding: . Paper presented at 8th Annual meeting of the Scandinavian Society for Biomaterials,Sigulda, Latvia, 6-8th of May 2015.
Open this publication in new window or tab >>Effects on organic degradation in the TiO2/H2O2/UV-Vis system
2015 (English)In: 8th Annual meeting of the Scandinavian Society for Biomaterials Proceeding, 2015Conference paper, Poster (with or without abstract) (Refereed)
National Category
Nano Technology Medical Engineering
Research subject
Engineering Science with specialization in Nanotechnology and Functional Materials; Engineering Science with specialization in Materials Science
Identifiers
urn:nbn:se:uu:diva-268494 (URN)
Conference
8th Annual meeting of the Scandinavian Society for Biomaterials,Sigulda, Latvia, 6-8th of May 2015
Available from: 2015-12-06 Created: 2015-12-06 Last updated: 2018-06-28
Fu, L., Andersson, M., Unosson, E., Engqvist, H. & Xia, W. (2015). Influence of alkali metal additives on phase transition of translucent ZrO2/SiO2 glass ceramics prepared by a sol-gel method. European Cells and Materials, 29
Open this publication in new window or tab >>Influence of alkali metal additives on phase transition of translucent ZrO2/SiO2 glass ceramics prepared by a sol-gel method
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2015 (English)In: European Cells and Materials, ISSN 1473-2262, E-ISSN 1473-2262, Vol. 29Article in journal, Meeting abstract (Refereed) Published
National Category
Ceramics
Identifiers
urn:nbn:se:uu:diva-266004 (URN)
Available from: 2015-11-04 Created: 2015-11-04 Last updated: 2018-02-08
Fu, L., Andersson, M., Unosson, E., Persson, C., Engqvist, H. & Xia, W. (2015). Influence of alkali metal additives on phase transition of translucent ZrO2/SiO2 glass ceramics prepared by a sol-gel method. European Cells and Materials, 29(S1), 10
Open this publication in new window or tab >>Influence of alkali metal additives on phase transition of translucent ZrO2/SiO2 glass ceramics prepared by a sol-gel method
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2015 (English)In: European Cells and Materials, ISSN 1473-2262, E-ISSN 1473-2262, Vol. 29, no S1, p. 10-Article in journal, Meeting abstract (Refereed) Published
National Category
Medical Materials
Research subject
Engineering Science with specialization in Materials Science
Identifiers
urn:nbn:se:uu:diva-284214 (URN)
Available from: 2016-04-15 Created: 2016-04-15 Last updated: 2018-02-08
Fu, L., Andersson, M., Unosson, E., Persson, C., Engqvist, H. & Xia, W. (2015). Influences of alkali metals additives on phase transition of translucent ZrO2/SiO2 glass ceramic prepared by sol-gel method. In: : . Paper presented at 8th meeting of the Scandinavian Society for Biomaterials.
Open this publication in new window or tab >>Influences of alkali metals additives on phase transition of translucent ZrO2/SiO2 glass ceramic prepared by sol-gel method
Show others...
2015 (English)Conference paper, Poster (with or without abstract) (Refereed)
National Category
Medical Materials
Identifiers
urn:nbn:se:uu:diva-284194 (URN)
Conference
8th meeting of the Scandinavian Society for Biomaterials
Available from: 2016-04-15 Created: 2016-04-15 Last updated: 2018-06-26
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