| 1. |
- Coelho, Paulo G., et al.
(författare)
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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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Ingår i: Engineering Mineralized and Load Bearing Tissue. - Cham : Springer. - 9783319223452 - 9783319223445 ; , s. 111-128
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Bokkapitel (övrigt vetenskapligt/konstnärligt)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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| 2. |
- Coelho, Paulo G., et al.
(författare)
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Microrobotized blasting improves the bone-to-textured implant response. A preclinical in vivo biomechanical study
- 2016
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Ingår i: Journal of The Mechanical Behavior of Biomedical Materials. - : Elsevier. - 1751-6161 .- 1878-0180. ; 56, s. 175-182
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Tidskriftsartikel (refereegranskat)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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| 3. |
- Jimbo, Ryo, et al.
(författare)
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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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Ingår i: 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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Tidskriftsartikel (refereegranskat)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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| 4. |
- Lahens, Bradley, et al.
(författare)
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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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Ingår i: Journal of The Mechanical Behavior of Biomedical Materials. - : Elsevier. - 1751-6161 .- 1878-0180. ; 63, s. 56-65
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Tidskriftsartikel (refereegranskat)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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| 5. |
- Lahens, Bradley, et al.
(författare)
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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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Ingår i: 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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Tidskriftsartikel (refereegranskat)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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| 6. |
- Marao, Heloisa F., et al.
(författare)
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Cortical and Trabecular Bone Healing Patterns and Quantification for Three Different Dental Implant Systems
- 2017
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Ingår i: International Journal of Oral & Maxillofacial Implants. - : Quintessence. - 0882-2786 .- 1942-4434. ; 32:3, s. 585-592
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Tidskriftsartikel (refereegranskat)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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| 7. |
- Neiva, Rodrigo, et al.
(författare)
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Guidelines for Clinical Management of Laser-Etched (Laser-Lok) Abutments in Two Different Clinical Scenarios : A Preclinical Laboratory Soft Tissue Assessment Study
- 2016
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Ingår i: The international journal of periodontics & restorative dentistry. - : Quintessence. - 0198-7569 .- 1945-3388. ; 36:3, s. 339-345
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Tidskriftsartikel (refereegranskat)abstract
- One-stage implants were placed in the mandibles of eight beagle dogs with laser-etched (LL) and machined abutments. After 4 weeks, half of the LL abutments were disconnected and reconnected after 10 minutes of saline storage, and the other half were replaced with a new LL abutment (impression simulation) with or without sulcus de-epithelialization. After abutment change, systems remained in vivo for 3 weeks. Results showed that LL abutments can be reconnected and that sulcus scoring prior to LL placement of one-stage implants receiving machined abutments may be beneficial.
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| 8. |
- Neiva, Rodrigo, et al.
(författare)
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The Effect of Laser-Etched Surface Design on Soft Tissue Healing of Two Different Implant Abutment Systems : An Experimental Study in Dogs
- 2016
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Ingår i: The international journal of periodontics & restorative dentistry. - : Quintessence. - 0198-7569 .- 1945-3388. ; 36:5, s. 673-679
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Tidskriftsartikel (refereegranskat)abstract
- This study describes the early soft tissue morphology around two different implant systems that received either smooth or laser-etched abutments in a beagle dog model. Implants were placed in the healed mandibular molar region of eight beagle dogs and allowed to heal for 7 weeks. When the most apical aspect of the junctional epithelium (JE) was above or within the upper half of the laser-etched region, fibers were oriented perpendicular to the abutment surface. In contrast, JE positioned within the lower half of the laser-etched region or within or below the implant-abutment gap level presented fibers oriented parallel to the abutment surface.
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