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| 2. |
- Moura, Camilla C G, et al.
(författare)
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Evaluation of human polymorphonuclear behavior on textured titanium and calcium-phosphate coated surfaces
- 2013
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Ingår i: Biomedical Materials. - : Bibliopolis, Edizioni di Filosofia e Scienze. - 1748-6041 .- 1748-605X. ; 8:3
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Tidskriftsartikel (refereegranskat)abstract
- Few studies have evaluated the effects of titanium (Ti) surface modifications on polymorphonuclear neutrophils (PMNs). Human PMNs' viability and release of key mediators-such as IL1β, IL6, TNFα, IL12, IL10, IL4, TGFβ1, IL8, IP-10, and Mig-were evaluated on three different Ti surface treatments: (1) machined Ti; (2) alumina-blasted and acid-etched Ti (AB/AE); and (3) calcium phosphate coating of 300-500 nm by ion beam onto the AB/AE Ti surface (CaP). A polystyrene surface was used as a negative control. The PMNs were purified from whole human blood and cultured for 6 h. Cell viability was determined by flow cytometry, and the supernatant was evaluated to determine the levels of cytokines and chemokines. Results showed that the percentage of viable cells was significantly lower on the CaP surface compared to the control (p < 0.05) relative to the other groups. No differences in the levels of IL8, MIG, and IP10 were detected between groups. Significantly higher levels of IL1β (p = 0.046) and TNFα (p = 0.016) were detected for the CaP surfaces compared to AB/AE surface only. The levels of IL4, IL10, and TGFβ1 secreted from the PMNs in the CaP group were significantly lower than in the control and machined groups (p < 0.05) that were statistically comparable to AB/AE. Overall, the addition of a thin CaP coating to the AB/AE Ti surface influenced the secretion profile of pro-inflammatory cytokines due to the higher release of pro-inflammatory cytokines (IL1β and TNFα) on these surfaces.
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| 3. |
- Bressan, E., et al.
(författare)
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Microbial Leakage at Morse Taper Conometric Prosthetic Connection: An In Vitro Investigation
- 2017
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Ingår i: Implant Dentistry. - : Ovid Technologies (Wolters Kluwer Health). - 1056-6163. ; 26:5, s. 756-761
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To evaluate in vitro the sealing capability at the prosthetic connection interface of 2 conometric systems. Materials and Methods: Two conometric systems with the same design and different material were used, for a total of 24 samples. Each sample was assembled by a tapered abutment and respective coping. In group A, the copings were made of gold, whereas in group B they were made of PEEK. Three mu L of mix bacterial suspension (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Fusobacterium nucleatum species) was inoculated into the abutment screw hole, and the coping was inserted on the abutment. Samples were immersed into culture tubes and incubated for 24, 48, and 72 hours into anaerobic conditions. Visual evaluation of turbidity was performed at each time point. Qualitative-quantitative assessment using real-time polymerase chain reaction was performed at 72 hours. Any difference between the groups was checked by means of Fisher exact test. Results: Microbial leakage occurred in both groups, and there was no statistically significant difference between groups. Microbial concentration resulted in a presence inferior to 1 x 10(2) copies/mu L in all positive assemblies. Conclusions: Because of the low bacterial count, it can be concluded that a minimal bacterial infiltration may be allowed by conometric interfaces for prosthetic connection.
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| 4. |
- Cecchinato, Francesca, et al.
(författare)
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Modulation of the nanometer pore size improves magnesium adsorption into mesoporous titania coatings and promotes bone morphogenic protein 4 expression in adhering osteoblasts
- 2016
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Ingår i: Dental Materials. - : Elsevier. - 0109-5641 .- 1879-0097. ; 32:7, s. E148-E158
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Mesoporous (MP) titania films used as implant coatings have recently been considered as release systems for controlled administration of magnesium to enhance initial osteoblast proliferation in vitro. Tuning of the pore size in such titania films is aimed at increasing the osteogenic potential through effects on the total loading capacity and the release profile of magnesium. Methods. In this study, evaporation-induced self-assembly (EISA) was used with different structure-directing agents to form three mesoporous films with average pore sizes of 2 nm (MP1), 6 nm (MP2) and 7 nm (MP3). Mg adsorption and release was monitored using quartz crystal microbalance with dissipation (QCM-D). The film surfaces were characterized with atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The effect of different Mg release on osteogenesis was investigated in human fetal osteoblasts (hFOB) using pre-designed osteogenesis arrays and real-time polymerase chain reaction (RT-PCR Results. Results showed a sustained release from all the films investigated, with higher magnesium adsorption into MP1 and MP3 films. No significant differences were observed in the surface nanotopography of the films, either with or without the presence of magnesium. MP3 films (7 nm pore size) had the greatest effect on osteogenesis, up-regulating 15 bone-related genes after 1 week of hFOB growth and significantly promoting bone morphogenic protein (BMP4) expression after 3 weeks of growth Significance. The findings indicate that the increase in pore width on the nano scale significantly enhanced the bioactivity of the mesoporous coating, thus accelerating osteogenesis without creating differences in surface roughness. (C) 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved
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| 5. |
- Jimbo, Ryo, et al.
(författare)
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The combined effects of undersized drilling and implant macrogeometry on bone healing around dental implants : an experimental study
- 2014
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Ingår i: International Journal of Oral and Maxillofacial Surgery. - : Elsevier. - 0901-5027 .- 1399-0020. ; 43:10, s. 1269-1275
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the effect of undersized preparations with two different implant macrogeometries. There were four experimental groups: group 1, conical implant with an undersized osteotomy of 3.2 mm; group 2, conical implant with an undersized osteotomy of 3.5 mm; group 3, cylindrical implant with an undersized osteotomy of 3.2 mm; group 4, cylindrical implant with an undersized osteotomy of 3.5 mm. Implants were placed in one side of the sheep mandible (n = 6). After 3 weeks, the same procedure was conducted on the other side; 3 weeks later, euthanasia was performed. All implants were 4 mm x 10 mm Insertion torque was recorded for all implants during implantation. Retrieved samples were subjected to histological sectioning and histomorphometry. Implants of groups 1 and 2 presented significantly higher insertion torque than those of groups 3 and 4 (P < 0.001). No differences in bone-to-implant contact or bone area fraction occupied were observed between the groups at 3 weeks (P > 0.24, and P > respectively), whereas significant differences were observed at 6 weeks between groups 1 and 2, and between groups 3 and 4 (P < 0.01). Undersized drilling affected the biological establishment of bone formation around both dental implant macrogeometries.
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| 6. |
- Jimbo, Ryo, et al.
(författare)
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The impact of a modified cutting flute implant design on osseointegration
- 2014
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Ingår i: International Journal of Oral and Maxillofacial Surgery. - : Elsevier. - 0901-5027 .- 1399-0020. ; 43:7, s. 883-888
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Tidskriftsartikel (refereegranskat)abstract
- Information concerning the effects of the implant cutting flute design on initial stability and its influence on osseointegration in vivo is limited. This study evaluated the early effects of implants with a specific cutting flute design placed in the sheep mandible. Forty-eight dental implants with two different macrogeometries (24 with a specific cutting flute design Blossom group; 24 with a self-tapping design - DT group) were inserted into the mandibular bodies of six sheep; the maximum insertion torque was recorded. Samples were retrieved and processed for histomorphometric analysis after 3 and 6 weeks. The mean insertion torque was lower for Blossom implants (P < 0.001). No differences in histomorphometric results were observed between the groups. At 3 weeks, P = 0.58 for bone-to-implant contact (BIC) and P = 0.52 for bone area fraction occupied (BAFO); at 6 weeks, P = 0.55 for BIC and P = 0.45 for BAFO. While no histomorphometric differences were observed, ground sections showed different healing patterns between the implants, with better peri-implant bone organization around those with the specific cutting flute design (Blossom group). Implants with the modified cutting flute design had a significantly reduced insertion torque compared to the DT implants with a traditional cutting thread, and resulted in a different healing pattern.
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| 7. |
- Johansson, C.B., et al.
(författare)
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3.16 Histological Analysis
- 2017. - 2
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Ingår i: Comprehensive Biomaterials II. - : Elsevier. - 9780081006924 ; , s. 335-363
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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.
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| 8. |
- Lindström, Martin J R, et al.
(författare)
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Volumetric measurement of dentoalveolar defects by means of intraoral 3D scanner and gravimetric model
- 2019
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Ingår i: Odontology. - : Springer. - 1618-1247 .- 1618-1255. ; 103:3, s. 353-359
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate the accuracy in volumetric measurements obtained on an experimental model using an intraoral scanner and a gravimetric method. Three identical partial dentate maxillary acrylic models with three fabricated alveolar defects, in anterior and posterior regions, were scanned using an intraoral scanner (20 scans/defects). The defects differed in terms of size and distance of neighbouring teeth. As references, replicas of each defect were created using a dimensional stable silicone impression material. After measuring the mass of each replica, the volume was calculated by dividing the mass of each replica by the density of the impression material. The defects had a volume, according to the gravimetric method, ranging from 40.5 to 143.7 mm. The scans were imported to metrology software for analyses. Accuracy was determined in terms of trueness and precision. The mean trueness for all defect types was 0.168 mm (SD 0.691, range 2.82). There was no statistical significant difference between the mean trueness for all defects measured (p = 0.910). The mean precision for all defect types was 0.147 mm (SD 0.524, range 2.86). There were no statistical significant differences between the dental models in regard to mean precision (p = 0.401), however, there were statistical significant differences between defects in position 1 and 2 (p = 0.002) and 1 and 3 (p = 0.001). Based on the findings of this study, the intraoral scanner utilized in the current study presented an acceptable level of accuracy when measuring volume of defects.
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| 9. |
- Sarendranath, A., et al.
(författare)
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Effect of low speed drilling on osseointegration using simplified drilling procedures
- 2015
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Ingår i: British Journal of Oral & Maxillofacial Surgery. - : Churchill Livingstone. - 0266-4356 .- 1532-1940. ; 53:6, s. 550-556
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Tidskriftsartikel (refereegranskat)abstract
- Our aim was to find out whether simplified drilling protocols would provide biological responses comparable to those of conventional drilling protocols at the low rotational speed of 400 rpm. Seventy-eight root form endosseous implants with diameters of 3.75, 4.2, and 5 mm were placed into canine tibias and allowed to heal for 3 and 5 weeks. After the dogs had been killed, the samples of implanted bone were retrieved and processed for non-decalcified histological sectioning. Bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) analyses were made on the histological sections. Implants treated by the simplified protocol resulted in BIC and BAFO values comparable to those obtained with the conventional drilling protocol, and there were no significant differences in the technique or diameter of the drilling. The results suggest that the simplified procedure gives biological outcomes comparable to those of the conventional procedure. (C) 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
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| 10. |
- Tovar, N., et al.
(författare)
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Evaluation of bone response to various anorganic bovine bone xenografts : an experimental calvaria defect study
- 2014
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Ingår i: International Journal of Oral and Maxillofacial Surgery. - : Churchill Livingstone. - 0901-5027 .- 1399-0020. ; 43:2, s. 251-260
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Tidskriftsartikel (refereegranskat)abstract
- This in vivo study investigated the in vivo performance of two newly developed synthetic bone substitutes and compared them to commercially available xenografts (Bio-Oss, Geistlich Pharma AG, Switzerland; OsteoGraf, Dentsply, USA). The materials were tested in a rabbit calvaria model, and the bone forming properties were observed at 4 and 8 weeks after implantation by means of histomorphometry and micro computed tomography (micro-CT). Defects without any graft material were used as negative controls. Micro-CT showed that all materials tested presented new bone formation that filled the defects at both time points, whereas the negative control presented less bone formation, with soft tissue infiltration into the defects. Comparable bone fill percentages were observed for histomorphometric and micro-CT results. Even though no statistically significant difference was found quantitatively between all of the bone graft substitute groups, a higher mean decrease in graft material filling the defects, along with higher remodelling activity, was evident for the experimental materials compared to the commercially available xenografts at 8 weeks. The results indicate that the experimental materials possess high degradability, along with osteoconduction comparable to commercially available xenografts.
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