Jan-eirik Ellingsen
University of Oslo, Institute of clinical dentistry, Faculty Member
— Stannous fluoride but not stannous chloride has shown a caries inhibiting effect in animal studies. The effect of aqueous solutions of stannous fluoride and stannous chloride on dental enamel surfaces was investigated by scanning... more
— Stannous fluoride but not stannous chloride has shown a caries inhibiting effect in animal studies. The effect of aqueous solutions of stannous fluoride and stannous chloride on dental enamel surfaces was investigated by scanning electron microscope and analytical electron microprobe. Some large globules and a continuous layer of small globules were observed after stannous fluoride treatment. The large globules were soluble in both water and alkali, whereas the small ones were only soluble in alkali. Both fluoride and tin were found to be present on the enamel surfaces by the electron microprobe after stannous fluoride treatment. The fluoride could not be detected after immersion in distilled water whereas alkali treatment removed the tin. The large fluoride‐containing globules may consist of calcium fluoride as this substance is known to be slightly soluble in water and soluble in alkali. Stannous chloride treatment gave a layer of small tin‐containing globules with properties similar to the layer formed on enamel treated with stannous fluoride. It is therefore suggested that the tin‐containing layer is not associated with caries protection whereas calcium fluoride‐like deposition on the enamel probably is a factor in the caries inhibition caused by stannous fluoride.
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– The effect of SnF2‐treatment of dentin surfaces was investigated by means of scanning electron microscopy (SEM) and electron microprobe analysis. Human dentin was treated with aqueous SnF2 solutions of concentrations varying from 1 to... more
– The effect of SnF2‐treatment of dentin surfaces was investigated by means of scanning electron microscopy (SEM) and electron microprobe analysis. Human dentin was treated with aqueous SnF2 solutions of concentrations varying from 1 to 10%. The treatment periods lasted for 1, 5, 10, or 60 min. Both tin and fluoride were identified on the surfaces. The concentration varied depending on the extensiveness of the treatment. Immersion in 1 M KOH for 15 h removed both tin and fluoride from the surfaces. This reaction was not observed after immersion in H2O for the same time period. Examination of the SnF2‐treated dentin surfaces showed a dense layer of globular particles and in addition some larger particles. The dentinal tubules were totally covered even after the treatment with the lowest concentration of SnF2. Deposition of tin‐ and fluoride‐coniaining globules on dentin surfaces may be of clinical interest. This layer may have importance both for the caries resistance of dentin and for hypersensitivity reactions.
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The progression of dentistry beyond restorative care to include regenerative therapy has been promoted by successes involving tooth root replacement using endosseous dental implants. This success of commercially pure (c.p.) titanium... more
The progression of dentistry beyond restorative care to include regenerative therapy has been promoted by successes involving tooth root replacement using endosseous dental implants. This success of commercially pure (c.p.) titanium endosseous implants in support of dental prostheses is now well documented. There is growing consensus that uncoated, threaded c.p. titanium implants can provide survival rates greater than 95% when used to support anterior single tooth restorations1 or mandibular prostheses supported by four to five parasymphyseal implants.2 Clinical successes notwithstanding, we confront the absence of significant data to guide future efforts to apply endosseous implant use in the more challenging environments of low density bone and high stress situations such as single implant replacements for molar teeth.
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ObjectivesThe primary objective was to assess osseointegration of implants with dehiscence defects grafted with a TiO2 scaffold. The secondary objective was to assess the performance of the scaffold in terms of mechanical stability and... more
ObjectivesThe primary objective was to assess osseointegration of implants with dehiscence defects grafted with a TiO2 scaffold. The secondary objective was to assess the performance of the scaffold in terms of mechanical stability and bone fill.Material and methodsFive minipigs had the mandibular premolars extracted. After healing, two dental implants (SLActive®, Institut Straumann AG, Basel, Switzerland) with associated semi‐cylindrical dehiscence defects (Ø = 6 mm, height = 10 mm) were installed in each quadrant. The defects were grafted with test scaffolds (n = 10) or control autologous bone blocks (n = 10). After 3 months submerged healing, the pigs were euthanized and the sites analysed by microcomputed tomography and histology.ResultsFour minipigs were available for second stage surgery; (n = 9) experimental and (n = 7) control sites. The mean bone‐to‐implant contact on the defect side was 82% (±10%) and 79% (±11%) in the test and control groups respectively. The mean level of first bone‐to‐implant contact was more coronal on the defect side in the test group 3.2 mm (±0.4 mm) than in the control group 3.6 mm (±1.1 mm). The defect area occupied by bone within the extent of the scaffold varied, but averaged 37% (±14.6%) whereas the material itself occupied 7.4% (±3.5%).ConclusionsWithin the limitations of the study, the results suggest that the novel synthetic scaffold material perform similar to the autologous bone block control with respect to implant osseointegration. The mechanical properties of the scaffold appeared sufficient to withstand clinical load in the present experimental model.
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... edu Samuel I. Stupp Feinberg School of Medicine, Northwestern University, Evanston, Illinois, s-stupp@ northwestern. edu Serge Szmukler-Moncler Salpétrière Hospital, University of Paris, Paris, France, ssm@ bluewin. ch ...
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Research Interests: Engineering, Chemistry, Biology, Medicine, Gene expression, and 15 moreBiological Sciences, Cell Differentiation, Mice, Animals, Cell Death, Osteoblast, Medical Physiology, Alkaline phosphatase, Cell Proliferation, Active Transport, Gene Family, Gene Expression Regulation, Cell Membrane, HMG CoA Reductase, and Medical and Health Sciences
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– Stored aqueous solutions of SnF2 showed a reduced effect on plaque acidogenicity after 24 weeks, this being paralleled by reduced concentrations of Sn2+ and lowered pH. The plaque inhibiting effect was, however, maintained unchanged,... more
– Stored aqueous solutions of SnF2 showed a reduced effect on plaque acidogenicity after 24 weeks, this being paralleled by reduced concentrations of Sn2+ and lowered pH. The plaque inhibiting effect was, however, maintained unchanged, indicating a different mechanism for this activity. Stored solutions caused a yellow dental stain probably consisting of SnS2.
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Titanium is the most frequently used material for dental implants and its uses for orthopedic prostheses are continuously increasing. This extensive use is based on the properties of the material, including a combination of corrosion... more
Titanium is the most frequently used material for dental implants and its uses for orthopedic prostheses are continuously increasing. This extensive use is based on the properties of the material, including a combination of corrosion resistance and biocompatibility with satisfactory mechanical performance. Mechanical qualities including fracture resistance or resistance to permanent deformation under long-term dynamic stress are essential. These qualities combined with an elastic modulus that facilitates stress transfer to the bone tissue surrounding the implant material make the biomechanical properties of titanium suitable for use as a load-bearing biomaterial. Successful long-term stability of the biomaterial in bone tissue relies on several factors; among them is the important surface connection between
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Research Interests: Chemistry, Dentistry, Biomedical Engineering, Biomaterials, Stem Cells, and 15 moreFluoride, Cytokines, PHOTOELECTRON SPECTROSCOPY, Medicine, Gene expression, Surface Chemistry, Humans, Interactions, Hydrofluoric acid, Primers, Surface Properties, Interleukins, Biological markers, Osteoblasts, and real time polymerase chain reaction
The degree and rate of fluoride absorption in five volunteers were studied after ingestion of SnF2 and NaF solutions or SnF2 toothpaste. The fluoride concentration in plasma was followed for eight hours. The relative bio-availability of... more
The degree and rate of fluoride absorption in five volunteers were studied after ingestion of SnF2 and NaF solutions or SnF2 toothpaste. The fluoride concentration in plasma was followed for eight hours. The relative bio-availability of fluoride was calculated and was similar for both the NaF and SnF2 solutions, although the latter solution showed a somewhat faster absorption rate. The bio-availability of fluoride from the SnF2 dentifrice was 85%.
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Surface chemistry evaluation is crucial in assessing the efficacy of chemical decontamination products for titanium implants. This study aimed to investigate the effectiveness of chemical decontamination solutions in cleaning a... more
Surface chemistry evaluation is crucial in assessing the efficacy of chemical decontamination products for titanium implants. This study aimed to investigate the effectiveness of chemical decontamination solutions in cleaning a contaminated dental implant surface and to evaluate the potential of combining Pluronic gel with hydrogen peroxide (NuBone®Clean) by evaluating pellicle disruption and re-formation on implant surfaces. In addition, ensuring safety with in vitro and human testing protocols. X-ray Photoelectron Spectroscopy (XPS) was utilised for surface analysis. All the tested gels had some effect on the surface cleanness except for PrefGel®. Among the tested chemical decontamination candidates, NuBone®Clean demonstrated effectiveness in providing a cleaner titanium surface. Furthermore, none of the tested chemical agents exhibited cytotoxic effects, and the safety assessment showed no adverse events. The results of this study highlight the significance of conducting comprehe...
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Objective The influence of radiation backscatter from titanium on DNA damage and migration capacity of human osteoblasts (OBs) and mesenchymal stem cells (MSCs) may be critical for the osseointegration of dental implants placed prior to... more
Objective The influence of radiation backscatter from titanium on DNA damage and migration capacity of human osteoblasts (OBs) and mesenchymal stem cells (MSCs) may be critical for the osseointegration of dental implants placed prior to radiotherapy. In order to evaluate effects of radiation backscatter, the immediate DNA damage and migration capacity of OBs and MSCs cultured on titanium or plastic were compared after exposure to ionizing irradiation. Materials and methods Human OBs and MSCs were seeded on machined titanium, moderately rough fluoride-modified titanium, or tissue culture polystyrene, and irradiated with nominal doses of 2, 6, 10, or 14 Gy. Comet assay was performed immediately after irradiation, while a scratch wound healing assay was initiated 24 h post-irradiation. Fluorescent live cell imaging documented the migration. Results DNA damage increased with higher dose and with backscatter from titanium, and MSCs were significantly more affected than OBs. All doses of ...
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Background Insufficient bone volume around an implant is a common obstacle when dental implant treatment is considered. Limited vertical or horizontal bone dimensions may lead to exposed implant threads following placement or a gap... more
Background Insufficient bone volume around an implant is a common obstacle when dental implant treatment is considered. Limited vertical or horizontal bone dimensions may lead to exposed implant threads following placement or a gap between the bone and implant. This is often addressed by bone augmentation procedures prior to or at the time of implant placement. This study evaluated bone healing when a synthetic TiO2 block scaffold was placed in circumferential peri-implant defects with buccal fenestrations. Methods The mandibular premolars were extracted and the alveolar bone left to heal for 4 weeks prior to implant placement in six minipigs. Two cylindrical defects were created in each hemi-mandible and were subsequent to implant placement allocated to treatment with either TiO2 scaffold or sham in a split mouth design. After 12 weeks of healing time, the samples were harvested. Microcomputed tomography (MicroCT) was used to investigate defect fill and integrity of the block scaff...
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Research Interests: Materials Science, Biomaterials, Fluoride, Cell Adhesion, Medicine, and 15 moreGene expression, Multidisciplinary, Cell Culture, Humans, Animals, Fluorides, Osteoblast, Osteocalcin, Osteogenesis, Bone Formation, Cell Proliferation, Osteoblasts, Materials Testing, Human Mesenchymal Stem Cells, and Gene Expression Regulation
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Polydimethylsiloxane (silicone oil) has an extremely low surface tension: It spreads over solid surfaces and forms a tenacious film which is hydrophobic and water-repellent. It is known that this liquid binds to hydroxyapatite and to... more
Polydimethylsiloxane (silicone oil) has an extremely low surface tension: It spreads over solid surfaces and forms a tenacious film which is hydrophobic and water-repellent. It is known that this liquid binds to hydroxyapatite and to dental enamel and changes the properties of these solids. It has been suggested that silicone oil may be applied to teeth and serve as a reservoir of lipid-soluble antibacterial substances which presumably will be slowly released into saliva due to their low solubility in water. The present paper reviews recent papers where this hypothesis is tested in vitro and in vivo. It was first shown that test tubes treated with the combination silicone oil and the lipid-soluble agent triclosan acquired a layer which inhibited bacterial growth in a culture of Streptococcus sobrinus (OMZ 176) which was grown in sucrose. Both growth in the medium and polysaccharide adsorption to the glass wall were inhibited. Silicone oil alone inhibited polysaccharide adsorption to...
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The purpose of the present study was to investigate whether a fluoride modification of the titanium surface would have an effect on bone response after implantation. Titanium-oxide-blasted titanium implants with and without fluoride... more
The purpose of the present study was to investigate whether a fluoride modification of the titanium surface would have an effect on bone response after implantation. Titanium-oxide-blasted titanium implants with and without fluoride modification were investigated in a rabbit tibia model. Quantitative analysis of surface roughness, biomechanical interlocking, and in vivo tissue reactions in rabbit bone at 1 and 3 months after placement were compared. The fluoride-modified test implants had a slightly smoother surface (Sa: 0.91 +/- 0.14 microm) than the unmodified control implants (Sa: 1.12 +/- 0.24 microm). Significantly higher removal torque values (85 +/- 16 Ncm vs 54 +/- 12 Ncm) and shear strength between bone and implants (23 +/- 9 N/mm2 vs 15 +/- 5 N/mm2) were measured for the fluoride-modified implants after 3 months. The histomorphometric evaluations demonstrated higher bone-to-implant contact for test implants at 1 month (35% +/- 14% vs 26% +/- 8%) and 3 months (39% +/- 11% v...
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Stannous fluoride was frequently used as a vehicle for fluoride in preparations used in caries prophylaxis in the 1960s and 1970s. At present it is not much used, although extensive research during the last two decades has established... more
Stannous fluoride was frequently used as a vehicle for fluoride in preparations used in caries prophylaxis in the 1960s and 1970s. At present it is not much used, although extensive research during the last two decades has established that stannous fluoride possesses several interesting properties which demonstrate that it deserves to be used in the prophylaxis against both gingivitis and caries. In the following, a review of the clinical properties of stannous fluoride is presented, together with a discussion of its merits compared with other fluoride vehicles in current use.
Research Interests: Dentistry, Fluoride, Medicine, Humans, Animals, and 4 moreBacteria, Dental, Dental Plaque, and Gingivitis
Topical application of 10 mM aqueous solutions of stannous fluoride inhibited caries in rats to a higher degree than 20 mM sodium fluoride, although the difference was not statistically significant. Furthermore, stannous fluoride reduced... more
Topical application of 10 mM aqueous solutions of stannous fluoride inhibited caries in rats to a higher degree than 20 mM sodium fluoride, although the difference was not statistically significant. Furthermore, stannous fluoride reduced the number of Strep. mutans in plaque significantly; stannous ions have an antibacterial effect. Stannous chloride and stannous tartrate did not reduce caries in the rats, probably because of the low concentrations of available stannous ions in these solutions at low pH. The high concentration of stannous ions in solutions of stannous fluoride is probably partly due to the reduced hydroxide formation resulting from the buffering effect of HF formed at low pH in this solution.
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Sixty-two ceramic implants (Frialit) were installed in 53 patients with agenesia or loss of single teeth due to traumata or infection. Sixty-three per cent of the implants were operated in immediately after tooth extraction, whereas the... more
Sixty-two ceramic implants (Frialit) were installed in 53 patients with agenesia or loss of single teeth due to traumata or infection. Sixty-three per cent of the implants were operated in immediately after tooth extraction, whereas the rest were installed in a healed bony alveolar ridge. Eighty-five per cent of the implants were replacements for maxillary incisors. The average observation period was 4 years. During this period 10 implants were removed due to lack of osseointegration. Seven of these implants were lost in the healing period, the remaining 3 were removed after installation of the suprastructure. Eighty-four percent of the implants were successful after 4 years. Trauma in the maxillary region have caused fracture of the implants in 5 patients. Such incidents create therapeutic problems difficult to solve satisfactorily.
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... More attention will probably be focused in the future on the biological effects of the surface ... Oxygen in phosphate may replace the fluoride and bind to titanium to create a covalently binding ... The fluoride ions which are... more
... More attention will probably be focused in the future on the biological effects of the surface ... Oxygen in phosphate may replace the fluoride and bind to titanium to create a covalently binding ... The fluoride ions which are released by this process may thus catalyze the new bone ...