Systemic and local effects of radiotherapy: an experimental study on implants placed in rats

Vegian, Mariana Raquel da Cruz; Costa, Bruno César Almeida; Santana-Melo, Gabriela de Fátima; Godoi, Fernanda Herrera Costa; Kaminagakura, Estela; Tango, Rubens Nisie; Prado, Renata Falchete do; Oliveira, Luciane Dias de; Federico, Claudio Antônio; Avelino, Sarah de Oliveira Marco; Neves, Rafael Marques; Vasconcellos, Luana Marotta Reis de

doi:10.1007/s00784-019-02946-5

Cited by 8 publications

(10 citation statements)

References 62 publications

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“…Bone loss, peri‐implant infection, and mobile or hyperplastic implant‐adjacent soft tissue are common causes of failed dental implantation in the reconstructed population, occurring in up to 30% of patients within 10 years 8,54,55 . Radiotherapy has been shown to reduce soft tissue and bony vascularization, lower infection resistance, and promote local inflammation, and is thought to exacerbate these factors, leading to increased rates of implant failure 54,55,59 . For these reasons, implantation was historically performed at least 6 months after mandibular reconstruction, with the delay extended to 12 months if the patient underwent adjuvant radiotherapy 60,61 .…”

Section: Dental Implantationmentioning

confidence: 99%

Mandibular rehabilitation: From the Andy Gump deformity to jaw‐in‐a‐day

Lilly

Petrisor

Wax

2021

Laryngoscope Investig Oto

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The mandible is a critical structure of the lower facial skeleton which plays an important role in several vital functions. Segmental resection of the mandible is at times required in patients with advanced oral cavity malignancies, primary mandibular tumors, and radiation or medication induced osteonecrosis. Mandibulectomy can significantly decrease quality of life, and thus mandibular reconstruction is an important aspect of the operative plan. Mandibular reconstruction is challenging due to the complex three‐dimensional anatomy of the mandible, and the precision required to restore dental occlusion in dentate patients. Significant advances have been made over the past decade in the ability to reconstruct and rehabilitate patients after a segmental mandibulectomy. This review will highlight these advances and discuss the timing of dental implantation.

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Section: Dental Implantationmentioning

confidence: 99%

Mandibular rehabilitation: From the Andy Gump deformity to jaw‐in‐a‐day

Lilly

Petrisor

Wax

2021

Laryngoscope Investig Oto

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“…An interval of 4 weeks was used between the placement of implants and the sacrifice of the animal to simulate a period of early osseointegration in humans that provides the basis for current treatment protocols. 18 , 24 , 25 In addition, this study used a single dose of 30 Gy in 2 weeks after implant placement, aiming to impair bone healing, 12 , 15 according to a previous study by Soares 25 (2015). The single dose of 30 Gy radiation was also used in a rabbit study that demonstrated a low volume of newly formed bone between the labels, which suggested that the rate of bone formation is slow.…”

Section: Discussionmentioning

confidence: 99%

“…Our biomechanical findings and micro-CT analysis are supported by studies showing that the presence of titanium dental implants in the irradiation field induces a backscattering effect of secondary electrons, increasing the deleterious effects of irradiation on bone tissue around the implant. 5,15 It has been very challenging for dentists to increase the success rate of dental implants in irradiated bone areas. Some human studies have indicated that exposure of bone to an irradiation dose exceeding 50 Gy impairs its ability to osseointegrate, increasing the failure risk of subsequent rehabilitation with a dental implant.…”

Section: Groupsmentioning

confidence: 99%

“…The results of this study cannot be directly extrapolated to clinical practice, but our findings may indicate a possible correlation with the irradiation response observed in humans. 15 In patients with head and neck cancer that need to undergo radiotherapy, the observation of previously installed implants should be an important consideration. 7,8 Given the lack of protocols that aim to address such situations, the irradiation field should be limited as much as possible to avoid implant areas, and patients need to return frequently to the dental office to analyse implant stability.…”

Section: Groupsmentioning

confidence: 99%

“…Gy has been demonstrated to be sufficient to cause a negative influence on bone/implant integrity in a rabbit study model. 11,12 Radiotherapy is one of the most common treatments for head and neck cancer patients, 4,13 and ionizing radiation can reduce bone healing capacity through the progressive fibrosis of blood vessels and soft tissue, 14 loss of osteoblast function 15 and damage to the collagen arrangement. 16 These effects can also negatively influence bone/implant integration.…”

Section: Introductionmentioning

confidence: 99%

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Biomechanical and morphological changes produced by ionizing radiation on bone tissue surrounding dental implant

Soares

Limirio

et al. 2020

J. Appl. Oral Sci.

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Biomechanical and morphological changes produced by ionizing radiation on bone tissue surrounding dental implant Objective: This study analyzed the effect of ionizing radiation on bone microarchitecture and biomechanical properties in the bone tissue surrounding a dental implant. Methodology: Twenty rabbits received three dental morse taper junction implants: one in the left tibia and two in the right tibia. The animals were randomized into two groups: the nonirradiated group (control group) and the irradiated group, which received 30 Gy in a single dose 2 weeks after the implant procedure. Four weeks after the implant procedure, the animals were sacrificed, and the implant/bone specimens were used for each experiment. The specimens (n=10) of the right tibia were examined by microcomputed tomography to measure the cortical volume (CtV, mm 3), cortical thickness (CtTh, mm) and porosity (CtPo, %). The other specimens (n=10) were examined by dynamic indentation to measure the elastic modulus (E, GPa) and Vickers hardness (VHN, N/mm 2) in the bone. The specimens of the left tibia (n=10) were subjected to pull-out tests to calculate the failure load (N), displacement (mm) up to the failure point and interface stiffness (N/mm). In the irradiated group, two measurements were performed: close, at 1 mm surrounding the implant surface, and distant, at 2.5 mm from the external limit of the first measurement. Data were analyzed using one-way ANOVA, Tukey's test and Student's t-test (α=0.05). Results: The irradiated bone closer to the implant surface had lower elastic modulus (E), Vickers hardness (VHN), Ct.Th, and Ct.V values and a higher Ct.Po value than the bone distant to the implant (P<0.04). The irradiated bone that was distant from the implant surface had lower E, VHN, and Ct.Th values and a higher Ct.Po value than the nonirradiated bone (P<0.04). The nonirradiated bone had higher failure loads, displacements and stiffness values than the irradiated bone (P<0.02). Conclusion: Ionizing radiation in dental implants resulted in negative effects on the microarchitecture and biomechanical properties of bone tissue, mainly near the surface of the implant.

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Rotary Jet-Spun Polycaprolactone/Hydroxyapatite and Carbon Nanotube Scaffolds Seeded with Bone Marrow Mesenchymal Stem Cells Increase Bone Neoformation

Machado-Paula

Corat

Vasconcellos

et al. 2022

ACS Appl. Bio Mater.

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Clinically, bone tissue replacements and/or bone repair are challenging. Strategies based on well-defined combinations of osteoconductive materials and osteogenic cells are promising to improve bone regeneration but still require improvement. Herein, we combined polycaprolactone (PCL) fibers, carbon nanotubes (CNT), and hydroxyapatite (nHap) nanoparticles to develop the next generation of bone regeneration material. Fibers formed by rotary jet spinning (RJS) instead of traditional electrospinning (ES) with embedded bone marrow mesenchymal stem cells (BMMSCs) showed the best outcomes to repair rat calvarial defects after 6 weeks. To understand this, it was observed that different morphologies were formed depending on the manufacturing method used. RJS fibers presented a particular topography with rough fibers, which allowed for better cellular growth and cell spreading in vitro around and into a three-dimensional (3D) mesh, while fibers made by ES were more smooth and cellular growth was only measured on the 3D mesh surface. The fibers with incorporated nHap/CNT nanoparticles enhanced in vitro cell performance as indicated by more cellular proliferation, alkaline phosphatase activity, proliferation, and deposition of calcium. Greater bone neoformation occurred by combining three characteristics: the presence of nHap and CNT nanoparticles, the topography of the RJS fibers, and the addition of BMMSCs. RJS fibers with nanoparticles and seeded with BMMSCs showed 10 136 mm 3 of bone neoformation, meaning a 10-fold increase compared to using RJS only and BMMSCs (0.853 mm 3 ) and a 5-fold increase from using ES only (2054 mm 3 ) after 6 weeks of implantation. Conversely, none of these approaches used individually showed any significant difference for in vivo bone neoformation, suggesting that their combination is essential for optimizing bone formation. In summary, our work generated a potential material composed of welldefined combinations of suitable scaffolds seeded with BMMSCs for enhancing numerous orthopedic tissue engineering applications.

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Systemic and local effects of radiotherapy: an experimental study on implants placed in rats

Cited by 8 publications

References 62 publications

Mandibular rehabilitation: From the Andy Gump deformity to jaw‐in‐a‐day

Mandibular rehabilitation: From the Andy Gump deformity to jaw‐in‐a‐day

Biomechanical and morphological changes produced by ionizing radiation on bone tissue surrounding dental implant

Rotary Jet-Spun Polycaprolactone/Hydroxyapatite and Carbon Nanotube Scaffolds Seeded with Bone Marrow Mesenchymal Stem Cells Increase Bone Neoformation

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