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4. |
- Persson, Ingemar, 1985-, et al.
(author)
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Sub-4 nm mapping of donor-acceptor organic semiconductor nanoparticle composition
- 2023
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In: Nanoscale. - : ROYAL SOC CHEMISTRY. - 2040-3364 .- 2040-3372. ; 15:13, s. 6126-6142
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Journal article (peer-reviewed)abstract
- We report, for the first time, sub-4 nm mapping of donor : acceptor nanoparticle composition in eco-friendly colloidal dispersions for organic electronics. Low energy scanning transmission electron microscopy (STEM) energy dispersive X-ray spectroscopy (EDX) mapping has revealed the internal morphology of organic semiconductor donor : acceptor blend nanoparticles at the sub-4 nm level. A unique element was available for utilisation as a fingerprint element to differentiate donor from acceptor material in each blend system. Si was used to map the location of donor polymer PTzBI-Si in PTzBI-Si:N2200 nanoparticles, and S (in addition to N) was used to map donor polymer TQ1 in TQ1:PC71BM nanoparticles. For select material blends, synchrotron-based scanning transmission X-ray microscopy (STXM), was demonstrated to remain as the superior chemical contrast technique for mapping organic donor : acceptor morphology, including for material combinations lacking a unique fingerprint element (e.g. PTQ10:Y6), or systems where the unique element is in a terminal functional group (unsaturated, dangling bonds) and can hence be easily damaged under the electron beam, e.g. F on PTQ10 donor polymer in the PTQ10:IDIC donor : acceptor blend. We provide both qualitative and quantitative compositional mapping of organic semiconductor nanoparticles with STEM EDX, with sub-domains resolved in nanoparticles as small as 30 nm in diameter. The sub-4 nm mapping technology reported here shows great promise for the optimisation of organic semiconductor blends for applications in organic electronics (solar cells and bioelectronics) and photocatalysis, and has further applications in organic core-shell nanomedicines.
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5. |
- Campos, Felipe E. B., et al.
(author)
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Are insertion torque and early osseointegration proportional? : A histologicevaluation
- 2015
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In: Clinical Oral Implants Research. - : John Wiley & Sons. - 0905-7161 .- 1600-0501. ; 26:11, s. 1256-1260
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Journal article (peer-reviewed)abstract
- ObjectivesThe objective of this histologic study was to determine the effect of three drilling protocols (oversized, intermediate, and undersized) on biologic responses to a single implant type at early healing periods (2weeks in vivo) in a beagle dog model. Materials and methodsTen beagle dogs were acquired and subjected to surgeries in the tibia 2weeks before euthanasia. During surgery, each dog received three Unitite implants, 4mm in diameter by 10mm in length, in bone sites drilled to 3.5, 3.75, and 4.0mm in final diameter. The insertion torque was recorded during surgery, and bone-to-implant contact (BIC), and bone area fraction occupied (BAFO) measured from the histology. Each outcome measure was compared between treatment conditions with the Wilcoxon signed-rank test. Bonferroni-corrected statistical significance was set to 95%. ResultsInsertion torque increased as an inverse function of drilling diameter, as indicated by significant differences in torque levels between each pair of conditions (P=0.005). BIC and BAFO levels were highest and statistically similar in the recommended and undersized conditions and significantly reduced in the oversized condition (P<0.01). ConclusionsReduced drilling dimensions resulted in increased insertion torque (primary stability). While BIC and BAFO were maximized when drilling the recommended diameter hole, only the oversized hole resulted in evidence of statistically reduced integration.
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6. |
- Coelho, Paulo G, et al.
(author)
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Alveolar buccal bone maintenance after immediate implantation with a surgical flap approach: a study in dogs.
- 2011
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In: The International journal of periodontics & restorative dentistry. - 0198-7569. ; 31:6
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Journal article (peer-reviewed)abstract
- This study evaluated buccal bone maintenance after implantation with a surgical flap approach immediately following tooth extraction in a dog model. Mandibular premolars of six dogs were extracted, and threaded implants of 4-mm diameter and 8-mm length with as-machined and dual acid-etched surfaces were placed through balanced procedures in the distal root extraction sockets with a full-thickness flap design. Submerged healing was allowed for 4 weeks, and following euthanization, bone-to-implant contact and buccal and lingual bone loss were evaluated. None of the parameters evaluated were indicative of an effect of implant surface in hindering bone loss around immediately placed implants. (Int J Periodontics Restorative Dent 2011;31:e80-e86.).
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7. |
- Coelho, Paulo G, et al.
(author)
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Effect of Si addition on Ca- and P-impregnated implant surfaces with nanometer-scale roughness: an experimental study in dogs.
- 2012
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In: Clinical oral implants research. - : Wiley. - 1600-0501 .- 0905-7161.
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Journal article (peer-reviewed)abstract
- Objectives: To investigate the effect of Si addition on a nanometer-scale roughness Ca and P implant surfaces in a canine tibia model by biomechanical and histomorphometric evaluations. Material and methods: The implant surfaces comprised a resorbable media CaP microblasted (control) and a CaP resorbable media+silica-boost microblasted (experimental) surfaces. Surfaces were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and optical interferometry (IFM) down to the nanometric level. The animal model involved the bilateral placement of control (n=24) and experimental surface (n=24) implants along the proximal tibiae of six dogs, remaining in vivo for 2 or 4 weeks. After euthanization, half of the specimens were torqued-to-interface failure, and the other half was subjected to histomorphologic and bone-to-implant contact (BIC) evaluation. Torque and BIC statistical evaluation was performed by the Friedman test at 95% level of significance, and comparisons between groups was performed by the Dunn test. Results: IFM and SEM observations depicted comparable roughness parameters for both implant surfaces on the micrometer and nanometer scales. XPS analysis revealed similar chemical composition, except for the addition of Si on the experimental group. Torque-to-interface failure and BIC mean values showed no significant differences (P=0.25 and 0.51, respectively) at both 2- and 4-week evaluation points for experimental and control groups. Early bone healing histomorphologic events were similar between groups. Conclusions: The experimental surface resulted in not significantly different biomechanical fixation and BIC relative to control. Both surfaces were biocompatible and osseoconductive. To cite this article: Coelho PG, Granato R, Marin C, Jimbo R, Lin S, Witek L, Suzuki M, Bonfante EA. Effect of Si addition on Ca- and P-impregnated implant surfaces with nanometer-scale roughness: an experimental study in dogs. Clin. Oral Impl. Res. xx, 2011; 000-000. doi: 10.1111/j.1600-0501.2010.02150.x.
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8. |
- Coelho, Paulo G., et al.
(author)
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Experimental and Clinical Knowledge of Nanometer Scale Designing on Endosteal Implants
- 2015
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In: Implant Surfaces and their Biological and Clinical Impact. - Berlin, Heidelberg : Springer. - 9783662453780 - 9783662513323 - 9783662453797 ; , s. 29-43
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Book chapter (peer-reviewed)abstract
- Recent advances in engineering methods and characterization have rendered the addition of nanometer scale features on endosteal implant surfaces. Such modifications usually occur hierarchically in tandem with modifications at the micrometer scale level, and its main objective is to support the bone response through enhanced interaction between the immediate and intermediate implant and host after surgical placement. This chapter describes the increasing basic science experimental basis for surface nanotopographical alterations and the limited clinical evidence of nanometer scale surface modifications.
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9. |
- Coelho, Paulo G., et al.
(author)
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Microrobotized blasting improves the bone-to-textured implant response. A preclinical in vivo biomechanical study
- 2016
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In: Journal of The Mechanical Behavior of Biomedical Materials. - : Elsevier. - 1751-6161 .- 1878-0180. ; 56, s. 175-182
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Journal article (peer-reviewed)abstract
- This study evaluated the effect of microrobotized blasting of titanium endosteal implants relative to their manually blasted counterparts. Two different implant systems were utilized presenting two different implant surfaces. Control surfaces (Manual) were fabricated by manually grit blasting the implant surfaces while experimental surfaces (Microblasted) were fabricated through a microrobotized system that provided a one pass grit blasting routine. Both surfaces were created with the same similar to 50 gm average particle size alumina powder at similar to 310 KPa. Surfaces were then etched with 37% HCl for 20 min, washed, and packaged through standard industry procedures. The surfaces were characterized through scanning electron microscopy (SEM) and optical interferometry, and were then placed in a beagle dog radius model remaining in vivo for 3 and 6 weeks. The implant removal torque was recorded and statistical analysis evaluated implant system and surface type torque levels as a function of time in vivo. Histologic sections were qualitatively evaluated for tissue response. Electron microscopy depicted textured surfaces for both manual and microblasted surfaces. Optical interferometry showed significantly higher S-a, S-q, values for the microblasted surface and no significant difference for S-ds and S-dr values between surfaces. In vivo results depicted that statistically significant gains in biomechanical fixation were obtained for both implant systems tested at 6 weeks in vivo, while only one system presented significant biomechanical gain at 3 weeks. Histologic sections showed qualitative higher amounts of new bone forming around microblasted implants relative to the manually blasted group. Microrobotized blasting resulted in higher biomechanical fixation of endosteal dental implants and should be considered as an alternative for impant surface manufacturing.
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10. |
- Coelho, Paulo G., et al.
(author)
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Osseointegration : hierarchical designing encompassing the macrometer, micrometer, and nanometer length scales
- 2015
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In: Dental Materials. - : Elsevier. - 0109-5641 .- 1879-0097. ; 31:1, s. 37-52
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Journal article (peer-reviewed)abstract
- Objective. Osseointegration has been a proven concept in implant dentistry and orthopedics for decades. Substantial efforts for engineering implants for reduced treatment time frames have focused on micrometer and most recently on nanometer length scale alterations with negligible attention devoted to the effect of both macrometer design alterations and surgical instrumentation on osseointegration. This manuscript revisits osseointegration addressing the individual and combined role of alterations on the macrometer, micrometer, and nanometer length scales on the basis of cell culture, preclinical in vivo studies, and clinical evidence. Methods. A critical appraisal of the literature was performed regarding the impact of dental implant designing on osseointegration. Results from studies with different methodological approaches and the commonly observed inconsistencies are discussed. Results. It is a consensus that implant surface topographical and chemical alterations can hasten osseointegration. However, the tailored combination between multiple length scale design parameters that provides maximal host response is yet to be determined. Signcance. In spite of the overabundant literature on osseointegration, a proportional inconsistency in findings hitherto encountered warrants a call for appropriate multivariable study designing to ensure that adequate data collection will enable osseointegration maximization and/or optimization, which will possibly lead to the engineering of endosteal implant designs that can be immediately placed/loaded regardless of patient dependent conditions.
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11. |
- Coelho, Paulo G., et al.
(author)
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Osseointegration of Plateau Root Form Implants : Unique Healing Pathway Leading to Haversian-Like Long-Term Morphology
- 2015
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In: Engineering Mineralized and Load Bearing Tissue. - Cham : Springer. - 9783319223452 - 9783319223445 ; , s. 111-128
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Book chapter (other academic/artistic)abstract
- Endosteal dental implants have been utilized as anchors for dental and orthopedic rehabilitations for decades with one of the highest treatment success rates in medicine. Such success is due to the phenomenon of osseointegration where after the implant surgical placement, bone healing results into an intimate contact between bone and implant surface. While osseointegration is an established phenomenon, the route which osseointegration occurs around endosteal implants is related to various implant design factors including surgical instrumentation and implant macro, micro, and nanometer scale geometry. In an implant system where void spaces (healing chambers) are present between the implant and bone immediately after placement, its inherent bone healing pathway results in unique opportunities to accelerate the osseointegration phenomenon at the short-term and its maintenance on the long-term through a haversian-like bone morphology and mechanical properties.
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12. |
- Coelho, Paulo G., et al.
(author)
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Revisiting the Role of Implant Design and Surgical Instrumentation on Osseointegration
- 2017
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In: Implant Aesthetics. - Cham : Springer. - 9783319507040 - 9783319507064 ; , s. 43-56
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Book chapter (peer-reviewed)abstract
- Osseointegration of metallic devices has shown to be successful in several biomedical fields. Despite the high success rates, continuous efforts to reduce osseointegration time have been marked by investigations considering a limited number of variables. Recent research has pointed that the interplay between surgical instrumentation and device macrogeometry not only plays a key role on both early and delayed stages of osseointegration but may also be key in how efficient smaller length scale designing (at the micro- and nanogeometrical levels) may be in hastening early stages of osseointegration. The present chapter focuses on how the different metallic device design length scales’ interplay (macro, micro, and nano) affects the bone response and how its understanding may affect the next generation of metallic device designing for osseointegration.
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13. |
- Gil, Luiz F., et al.
(author)
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Progressive plateau root form dental implant osseointegration : a human retrieval study
- 2015
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In: Journal of Biomedical Materials Research. Part B - Applied biomaterials. - : John Wiley & Sons. - 1552-4973 .- 1552-4981. ; 103:6, s. 1328-1332
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Journal article (peer-reviewed)abstract
- Although preclinical and sparse human histology retrieval studies have shown that the interface between implant and bone is constantly remodeling, no human retrieval database has been developed to determine the effect of functional loading time and other clinical/implant design variables on osseointegration. The present study tested the hypothesis that bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) increase over functional loading time around dental implants. Due to prosthetic retreatment reasons, 93 human implant retrievals from the same manufacturer (Bicon LLC, Boston, MA, USA) were obtained over a period of approximately 15 years. The retrieved implants were under functional loading from 120 days to approximate to 18 years and were histomorphologic/metrically evaluated. BIC/BAFO were assessed as a function of multiple independent variables: implant surface type, diameter, length, jaw (maxilla/mandible), region (anterior/posterior), and time of functional loading. The results showed that both BIC and BAFO increased over time independently of implant design/clinical variables, supporting the postulated hypothesis. (c) 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1328-1332, 2015.
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14. |
- Granato, Rodrigo, et al.
(author)
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Osteointegrative and microgeometric comparison between micro-blasted and alumina blasting/acid etching on grade II and V titanium alloys (Ti-6Al-4V).
- 2019
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In: Journal of The Mechanical Behavior of Biomedical Materials. - : Elsevier. - 1751-6161 .- 1878-0180. ; 97, s. 288-295
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Journal article (peer-reviewed)abstract
- This study evaluated the effect of alumina-blasted/acid-etched (AB/AE) or microabrasive blasting (C3-Microblasted) surface treatment on the osseointegration of commercially-pure Ti (grade II) and Ti-6Al-4V alloy (grade V) implants compared to as-machined surfaces. Surface characterization was performed by scanning electron microscopy and optical interferometry (IFM) to determine roughness parameters (Sa and Sq, n=3 per group). One-hundred forty-four implants were placed in the radii of 12 beagle dogs, for histological (n=72, bone-to-implant contact - BIC and bone-area-fraction occupancy -BAFO) and torque to interface failure test at 3 and 6 weeks (n=72). SEM and IFM revealed a significant increase in surface texture for AB/AE and C3-Microblasted surfaces compared to machined surface, regardless of titanium substrate. Torque-to-interface failure test showed significant increase in values from as-machined to AB/AE and to C3-Microblasted. Considering time in vivo, alloy grade, and surface treatment, the C3-microblasted presented higher mean BIC values relative to AB/AE and machined surfaces for both alloy types. BAFO levels were significantly higher for both textured surfaces groups relative to the machined group at 3 weeks, but differences were not significant between the three surfaces for each alloy type at 6 weeks. Surface treatment resulted in roughness that improved osseointegration in Grade II and V titanium substrates.
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15. |
- Jimbo, Ryo, et al.
(author)
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Regeneration of the cementum and periodontal ligament using local BDNF delivery in class II furcation defects
- 2018
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In: Journal of Biomedical Materials Research. Part B - Applied biomaterials. - : John Wiley & Sons. - 1552-4973 .- 1552-4981. ; 106:4, s. 1611-1617
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Journal article (peer-reviewed)abstract
- Periodontal furcation defects are usually addressed by the placement of a physical barrier which may limit the regenerative potential of periodontal wounds. This study morphometrically quantified the regenerative effect of brain-derived neurotrophic factor (BDNF) in furcation defects in a non-human primate model. Grade II furcation defects (with and without induced inflammation prior to surgery) were created on the first and second molars of eight non-human primates. Defects were treated with open flap debridement and subsequently filled with either: Group A; BDNF (500 µg mL−1) in high-molecular weight-hyaluronic acid (HMW-HA), Group B; BDNF (50 µg mL−1) in HMW-HA, Group C; HMW-HA acid only, Group D; unfilled defect, or Group E; BDNF (500 µg mL−1) in saline. Periodontal wound healing was observed every 2 weeks by computed-tomography. At 11 weeks all animals were sacrificed and maxillary and mandibular block biopsies were referred for nondecalcified histology. Linear measurements of new cementum (cellular and acellular) and periodontal ligament (PDL) formation were performed. Computerized-tomography reconstruction and software quantification demonstrated successful bone fill for all groups. However, histometric assessment demonstrated significantly higher level of total periodontal regeneration for the 500 µg mL−1 BDNF HMW-HA relative to all other groups. No significant differences in cementogenesis were observed among groups. Significantly higher acellular cementum formation was observed for sites where inflammation was not induced prior to surgical procedures. While all groups experienced similar bone fill and cementogenesis, the 500 µg mL−1 BDNF HMW-HA appeared to most effectively repair PDL (minimum increase of ∼22% relative to all groups; over 200% relative to unfilled defects).
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16. |
- Jimbo, Ryo, et al.
(author)
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The Effect of Brain-Derived Neurotrophic Factor on Periodontal Furcation Defects
- 2014
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In: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 9:1
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Journal article (peer-reviewed)abstract
- This study aimed to observe the regenerative effect of brain-derived neurotrophic factor (BDNF) in a non-human primate furcation defect model. Class II furcation defects were created in the first and second molars of 8 non-human primates to simulate a clinical situation. The defect was filled with either, Group A: BDNF (500 mu g/ml) in high-molecular weight-hyaluronic acid (HMW-HA), Group B: BDNF (50 mu g/ml) in HMW-HA, Group C: HMW-HA acid only, Group D: empty defect, or Group E: BDNF (500 mu g/ml) in saline. The healing status for all groups was observed at different time-points with micro computed tomography. The animals were euthanized after 11 weeks, and the tooth-bone specimens were subjected to histologic processing. The results showed that all groups seemed to successfully regenerate the alveolar buccal bone, however, only Group A regenerated the entire periodontal tissue, i.e., alveolar bone, cementum and periodontal ligament. It is suggested that the use of BDNF in combination with a scaffold such as the hyaluronic acid in periodontal furcation defects may be an effective treatment option.
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17. |
- Lahens, Bradley, et al.
(author)
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Biomechanical and histologic basis of osseodensification drilling for endosteal implant placement in low density bone. An experimental study in sheep
- 2016
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In: Journal of The Mechanical Behavior of Biomedical Materials. - : Elsevier. - 1751-6161 .- 1878-0180. ; 63, s. 56-65
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Journal article (peer-reviewed)abstract
- A bone drilling concept, namely osseodensification, has been introduced for the placement of endosteal implants to increase primary stability through densification of the osteotomy walls. This study investigated the effect of osseodensification on the initial stability and early osseointegration of conical and parallel walled endosteal implants in low density bone. Five male sheep were used. Three implants were inserted in the ilium, bilaterally, totaling 30 implants (n=15 conical, and n=15 parallel). Each animal received 3 implants of each type, inserted into bone sites prepared as follows: (i) regular-drilling (R: 2 mm pilot, 3.2 mm, and 3.8 mm twist drills), (ii) clockwise osseodensification (CW), and (iii) counterclockwise (CCW) osseodensification drilling with Densah Bur (Versah, Jackson, MI, USA): 2.0 mm pilot, 2.8 mm, and 3.8 mm multi-fluted burs. Insertion torque as a function of implant type and drilling technique, revealed higher values for osseodensification relative to R-drilling, regardless of implant macrogeometry. A significantly higher bone-to-implant contact (BIC) for both osseodensification techniques (p<0.05) was observed compared to R-drilling. There was no statistical difference in BIC as a function of implant type (p=0.58), nor in bone-area-fraction occupancy (BAFO) as a function of drilling technique (p=0.22), but there were higher levels of BAFO for parallel than conic implants (p=0.001). Six weeks after surgery, new bone formation along with remodeling sites was observed for all groups. Bone chips in proximity with the implants were seldom observed in the R-drilling group, but commonly observed in the CW, and more frequently under the CCW osseodensification technique. In low-density bone, endosteal implants present higher insertion torque levels when placed in osseodensification drilling sites, with no osseointegration impairment compared to standard subtractive drilling methods.
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18. |
- Lahens, Bradley, et al.
(author)
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The effect of osseodensification drilling for endosteal implants with different surface treatments : A study in sheep.
- 2019
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In: Journal of Biomedical Materials Research. Part B - Applied biomaterials. - : John Wiley & Sons. - 1552-4973 .- 1552-4981. ; 107:3, s. 615-623
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Journal article (peer-reviewed)abstract
- This study investigated the effects of osseodensification drilling on the stability and osseointegration of machine-cut and acid-etched endosteal implants in low-density bone. Twelve sheep received six implants inserted into the ilium, bilaterally (n = 36 acid-etched, and n = 36 as-machined). Individual animals received three implants of each surface, placed via different surgical techniques: (1) subtractive regular-drilling (R): 2.0 mm pilot, 3.2 and 3.8 mm twist drills); (2) osseodensification clockwise-drilling (CW): Densah Bur (Versah, Jackson, MI) 2.0 mm pilot, 2.8, and 3.8 mm multifluted tapered burs; and (3) osseodensification counterclockwise-drilling (CCW) Densah Bur 2.0 mm pilot, 2.8 mm, and 3.8 mm multifluted tapered burs. Insertion torque was higher in the CCW and CW-drilling compared to the R-drilling (p < 0.001). Bone-to-implant contact (BIC) was significantly higher for CW (p = 0.024) and CCW-drilling (p = 0.006) compared to the R-drilling technique. For CCW-osseodensification-drilling, no statistical difference between the acid-etched and machine-cut implants at both time points was observed for BIC and BAFO (bone-area-fraction-occupancy). Resorbed bone and bone forming precursors, preosteoblasts, were observed at 3-weeks. At 12-weeks, new bone formation was observed in all groups extending to the trabecular region. In low-density bone, endosteal implants inserted via osseodensification-drilling presented higher stability and no osseointegration impairments compared to subtractive regular-drilling technique, regardless of evaluation time or implant surface. (c) 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 00B: 000-000, 2018.
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19. |
- Marao, Heloisa F., et al.
(author)
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Cortical and Trabecular Bone Healing Patterns and Quantification for Three Different Dental Implant Systems
- 2017
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In: International Journal of Oral & Maxillofacial Implants. - : Quintessence. - 0882-2786 .- 1942-4434. ; 32:3, s. 585-592
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Journal article (peer-reviewed)abstract
- Purpose: The present study hypothesized that different bone healing patterns through initial stages of osseointegration would be observed when three distinct commercially available implant systems (Nobel Groovy, Implacil, and Zimmer TSV) were used, leading to significant variations in histometric levels of total bone and new bone formation during the osseointegration process. Materials and Methods: A total of 48 implants were placed bilaterally on the tibias of eight beagle dogs and allowed to heal for 2 and 6 weeks. Following euthanasia, nondecalcified specimens were processed for morphologic and histometric evaluation. Bone-to-implant contact (BIC) and new bone area fraction occupancy (BAFO) analyses for native and new bone were performed along the whole perimeter of each implant and separately for the cortical and trabecular bone regions. Results: Morphologic evaluation of cortical bone presented different healing patterns and osseointegration levels for different implant systems as time elapsed in vivo. Interfacial remodeling was the chief healing pattern in Zimmer implants, while a combination of interfacial remodeling and healing chambers was observed in Nobel and Implacil implants. When trabecular bone was evaluated, similar bone healing patterns were observed between systems despite different levels of osseointegration observed as a function of implantation time, implant system, and native and/or new bone BIC and BAFO. Conclusion: Different implant systems led to different healing patterns during early stages of osseointegration. Such variation in pattern was more noticeable in the cortical regions compared to the trabecular regions. The variation in bone healing pattern did significantly influence overall indicators of native and new BIC and BAFO during the osseointegration process. The postulated hypothesis was accepted.
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20. |
- Tovar, Nick, et al.
(author)
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Bone Regeneration Around Implants Placed in Fresh Extraction Sockets Covered with a Dual-Layer PTFE/Collagen Membrane : An Experimental Study in Dogs
- 2014
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In: The international journal of periodontics & restorative dentistry. - : Quintessence. - 0198-7569 .- 1945-3388. ; 34:6, s. 849-855
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Journal article (peer-reviewed)abstract
- This study investigated whether the use of a dual-layer polytetrafluoro ethylene (PTFE)/porcine-derived bioresorbable pericardium membrane enhances the osseointegration around implants compared to a single-layer porcine-derived bioresorbable pericardium membrane and a no-membrane control group. Endosseous implants were placed in the fresh extraction sockets of beagles. At 6 weeks, bone loss and apical soft tissue migration occurred in the control group, whereas bone successfully formed to the neck of the implant for the single-layer porcine-derived bioresorbable pericardium membrane group. The dual-layer PTFE/porcine-derived bioresorbable pericardium membrane showed bone growth coronal to the neck of the implant. Bone-to-implant contact and buccal bone loss were respectively higher and lower relative to the single-layer but not statistically different.
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21. |
- Zambuzzi, Willian F., et al.
(author)
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Nanometer Scale Titanium Surface Texturing Are Detected by Signaling Pathways Involving Transient FAK and Src Activations
- 2014
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In: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 9:7
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Journal article (peer-reviewed)abstract
- Background: It is known that physico/chemical alterations on biomaterial surfaces have the capability to modulate cellular behavior, affecting early tissue repair. Such surface modifications are aimed to improve early healing response and, clinically, offer the possibility to shorten the time from implant placement to functional loading. Since FAK and Src are intracellular proteins able to predict the quality of osteoblast adhesion, this study evaluated the osteoblast behavior in response to nanometer scale titanium surface texturing by monitoring FAK and Src phosphorylations. Methodology: Four engineered titanium surfaces were used for the study: machined (M), dual acid-etched (DAA), resorbable media microblasted and acid-etched (MBAA), and acid-etch microblasted (AAMB). Surfaces were characterized by scanning electron microscopy, interferometry, atomic force microscopy, x-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy. Thereafter, those 4 samples were used to evaluate their cytotoxicity and interference on FAK and Src phosphorylations. Both Src and FAK were investigated by using specific antibody against specific phosphorylation sites. Principal Findings: The results showed that both FAK and Src activations were differently modulated as a function of titanium surfaces physico/chemical configuration and protein adsorption. Conclusions: It can be suggested that signaling pathways involving both FAK and Src could provide biomarkers to predict osteoblast adhesion onto different surfaces.
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