{ "id": "epv6fhe4s2", "slug": "bioglass-45s5", "title": "Bioglass 45S5", "updated": "2026-10-15", "topic_path": [ { "id": "technology", "label": "Technology and the built world", "api_url": "https://www.edgepedia.org/api/v1/topics/technology" }, { "id": "technology.engineering", "label": "Engineering and manufacturing", "api_url": "https://www.edgepedia.org/api/v1/topics/technology.engineering" }, { "id": "technology.engineering.engineering.materials.metallurgy", "label": "Materials science and metallurgy", "api_url": "https://www.edgepedia.org/api/v1/topics/technology.engineering.engineering.materials.metallurgy" }, { "id": "technology.engineering.engineering.materials.metallurgy.ceramics-glass-and-minerals", "label": "Ceramics, glass, and minerals", "api_url": "https://www.edgepedia.org/api/v1/topics/technology.engineering.engineering.materials.metallurgy.ceramics-glass-and-minerals" }, { "id": "technology.engineering.engineering.materials.metallurgy.ceramics-glass-and-minerals.bioceramics-and-dental-cements", "label": "Bioceramics and dental cements", "api_url": "https://www.edgepedia.org/api/v1/topics/technology.engineering.engineering.materials.metallurgy.ceramics-glass-and-minerals.bioceramics-and-dental-cements" } ], "geo": [ { "id": "geo.us.t1946.technology.engineering.engineering.materials.metallurgy.ceramics-glass-and-minerals", "label": "United States · 1946 to 2000: Ceramics, glass, and minerals", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us.t1946.technology.engineering.engineering.materials.metallurgy.ceramics-glass-and-minerals", "path": [ { "id": "geo.us", "label": "United States", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us" }, { "id": "geo.us.t1946", "label": "United States · 1946 to 2000", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us.t1946" }, { "id": "geo.us.t1946.technology", "label": "Technology and the built world", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us.t1946.technology" }, { "id": "geo.us.t1946.technology.engineering", "label": "Engineering and manufacturing", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us.t1946.technology.engineering" }, { "id": "geo.us.t1946.technology.engineering.engineering.materials.metallurgy", "label": "Materials science and metallurgy", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us.t1946.technology.engineering.engineering.materials.metallurgy" }, { "id": "geo.us.t1946.technology.engineering.engineering.materials.metallurgy.ceramics-glass-and-minerals", "label": "Ceramics, glass, and minerals", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.us.t1946.technology.engineering.engineering.materials.metallurgy.ceramics-glass-and-minerals" } ] } ], "excerpt": "Bioglass 45S5 is a silicate bioactive glass discovered in 1969 by Larry L. Hench, the first synthetic material shown to bond directly with living bone.", "snippet": "Bioglass 45S5 is a silicate bioactive glass discovered in 1969 by Larry L. Hench, the first synthetic material shown to bond directly with living bone.", "node": "technology.engineering.engineering.materials.metallurgy.ceramics-glass-and-minerals.bioceramics-and-dental-cements", "markdown": "# Bioglass 45S5\n\n**Bioglass 45S5** is a silicate bioactive glass composed of 45 weight percent silica (SiO₂), 24.5 percent sodium oxide (Na₂O), 24.5 percent calcium oxide (CaO), and 6 percent phosphorus pentoxide (P₂O₅), discovered in 1969 by [Larry L. Hench](https://www.edgepedia.org/larry-l-hench) at the [University of Florida](https://www.edgepedia.org/university-of-florida) as the first synthetic material shown to form a direct chemical bond with living bone[1](https://pmc.ncbi.nlm.nih.gov/articles/PMC3696226/) • [2](https://pmc.ncbi.nlm.nih.gov/articles/PMC7839003/). It has been in clinical use since 1985 and is marketed under trade names including Bioglass®, PerioGlas®, and Biogran®[3](https://pubmed.ncbi.nlm.nih.gov/17122907/) • [4](https://www.spandidos-publications.com/10.3892/wasj.2026.476).\n\n| Key fact | Detail |\n|---|---|\n| Composition | 45 wt% SiO₂, 24.5 wt% Na₂O, 24.5 wt% CaO, 6 wt% P₂O₅[1](https://pmc.ncbi.nlm.nih.gov/articles/PMC3696226/) |\n| Discovery | 1969, Larry L. Hench, University of Florida; first publication 1971[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC7839003/) • [5](https://onlinelibrary.wiley.com/doi/10.1002/jbm.820050611) |\n| Clinical use | In clinical use since 1985[3](https://pubmed.ncbi.nlm.nih.gov/17122907/) |\n| Key products | PerioGlas® (90–170 µm particles) and Biogran® (300–355 µm particles)[6](https://pmc.ncbi.nlm.nih.gov/articles/PMC8470635/) |\n| Physical properties | Glass transition near 520 °C, crystallization near 610 °C, density 2.7 g/cm³, elastic modulus about 35 GPa[4](https://www.spandidos-publications.com/10.3892/wasj.2026.476) |\n| Main limitation | Fracture toughness of roughly 0.7–0.9 MPa·m½, well below cortical bone, restricting load-bearing use[4](https://www.spandidos-publications.com/10.3892/wasj.2026.476) |\n\n## Discovery\n\nIn the late 1960s Hench, then a materials scientist at the University of Florida, was working under funding from the U.S. Army medical branch amid concern over wounded soldiers returning from the [Vietnam War](https://www.edgepedia.org/vietnam-war). He later described the discovery as the result of a chance conversation with an Army officer, the funding award, and a fortunate selection of composition within the Na₂O–CaO–P₂O₅–SiO₂ phase diagram[7](https://mse.ufl.edu/larry-hench-inventor-of-bioglass-and-childrens-author-dies-at-age-77/). The composition was reached after a two-year study of the Na₂O–CaO–SiO₂ system, in which 45S5 sits near a ternary eutectic[8](https://pmc.ncbi.nlm.nih.gov/articles/PMC10342775/).\n\nHench, R. J. Splinter, W. C. Allen, and T. K. Greenlee published the first report in November 1971 in the *Journal of Biomedical Materials Research*, describing bonding mechanisms at the interface of ceramic prosthetic materials[5](https://onlinelibrary.wiley.com/doi/10.1002/jbm.820050611). Before this work, biomaterials had been chosen to be as bio-inert as possible to minimize scar tissue; bioactive glasses introduced a second generation of materials that bond to host tissue at the interface[3](https://pubmed.ncbi.nlm.nih.gov/17122907/).\n\n## Composition and structure\n\nThe designation 45S5 encodes the composition: 45 weight percent SiO₂, with a network connectivity value of about 2.11[4](https://www.spandidos-publications.com/10.3892/wasj.2026.476). Three compositional features govern its bioactivity: a silica content below 60 mol percent, high Na₂O and CaO content as network modifiers, and a high CaO/P₂O₅ ratio[9](https://archive.lib.cmu.ac.th/full/T/2013/mat40513wl_ch2.pdf). Sodium and calcium ions break Si–O–Si bridging bonds, creating non-bridging oxygen sites that allow rapid ionic exchange with biological fluids[4](https://www.spandidos-publications.com/10.3892/wasj.2026.476). Phosphorus is present mainly as orthophosphate groups rather than as part of the silicate network, and these groups act as nucleation sites for apatite precipitation[4](https://www.spandidos-publications.com/10.3892/wasj.2026.476).\n\nComparative structural studies place 45S5 as the most depolymerized of the three best-known bioactive glasses (45S5, S53P4, and 13-93), consistent with its lowest silica content. This structure explains its high solubility and fast reactivity in vivo relative to the other two compositions, and at a given temperature 45S5 has the lowest viscosity of the three[10](https://pmc.ncbi.nlm.nih.gov/articles/PMC11826416/).\n\n## Mechanism of bioactivity\n\nWhen 45S5 contacts physiological fluid, a sequence of surface reactions begins with ion exchange, releasing soluble silica and calcium ions. These ions raise the local supersaturation until an amorphous calcium-phosphate film precipitates, which densifies through brushite and monetite intermediates and matures toward hydroxyapatite; in bone, the final layer is hydroxycarbonate apatite (HCA), which chemically bonds to collagen fibrils[11](https://link.springer.com/article/10.1007/s10266-025-01162-w) • [9](https://archive.lib.cmu.ac.th/full/T/2013/mat40513wl_ch2.pdf). The released soluble Si⁴⁺ and Ca²⁺ ions also act as biological signals: they increase the expression of an osteoblast mitogenic growth factor and stimulate bone growth around the implant interface[12](https://pmc.ncbi.nlm.nih.gov/articles/PMC10169491/).\n\nHench classified 45S5 as a class A bioactive material, meaning it is both osteoconductive and osteoproducive; class A materials such as 45S5 promote tissue formation faster than class B materials, which dissolve more slowly[13](https://pmc.ncbi.nlm.nih.gov/articles/PMC5872110/). Hench also introduced a quantitative bioactivity index, and 45S5 ranks among the highest values of any bioactive material, forming bonds with bone within days to weeks of implantation in animal models[4](https://www.spandidos-publications.com/10.3892/wasj.2026.476) • [20](https://pubmed.ncbi.nlm.nih.gov/11205439/).\n\n## Clinical products and applications\n\nThe two main commercially available products based on the 45S5 composition, PerioGlas® (NovaBone Products) and Biogran® (BIOMET 3i), differ only in particle size distribution: PerioGlas particles range from 90 to 170 µm and Biogran particles from 300 to 355 µm[6](https://pmc.ncbi.nlm.nih.gov/articles/PMC8470635/). PerioGlas was the first NovaBone particulate material on sale in the United States in 1993 and obtained the CE Mark in Europe in 1995; it was first used to replace bone loss from periodontal disease, and in 1996 the FDA cleared additional dental indications such as alveolar ridge improvement at tooth extraction sites[6](https://pmc.ncbi.nlm.nih.gov/articles/PMC8470635/). FDA 510(k) documentation describes PerioGlas as a single-phase 45S5 particulate device, an osteoconductive bone void filler for oral, dental intraosseous, and craniofacial defects[14](https://www.accessdata.fda.gov/cdrh_docs/pdf5/K053387.pdf).\n\n[Clinical trial](https://www.edgepedia.org/clinical-trial) results show that 45S5 can be employed successfully as a bone substitute, alone or in combination with autologous bone, for bone and dental trauma and diseases including osteoporosis, cancer, and infections[6](https://pmc.ncbi.nlm.nih.gov/articles/PMC8470635/). When used in periodontal procedures, 45S5 aids the filling of alveolar defects and improves attachment levels; within endodontics, it appears promising for sealing root ends and capping the pulp; toothpastes that contain it plug open dentinal tubules, easing hypersensitivity; and applied as a surface layer on titanium implants, it promotes osseointegration in the early healing phase.[4](https://www.spandidos-publications.com/10.3892/wasj.2026.476) A controlled trial by Froum and colleagues reported greater probing depth reduction (4.26 versus 3.44 mm) and clinical attachment level gain (2.96 versus 1.54 mm) at 45S5-treated sites compared with open-flap debridement alone at 12 months[4](https://www.spandidos-publications.com/10.3892/wasj.2026.476).\n\nAlongside 45S5, the melt-derived composition S53P4 (commercialized as BonAlive®) holds FDA approval; BonAlive, developed in Finland starting from the 45S5 composition, is used in orthopedics as a bone graft substitute[13](https://pmc.ncbi.nlm.nih.gov/articles/PMC5872110/) • [15](https://pmc.ncbi.nlm.nih.gov/articles/PMC9680477/).\n\n## Limitations\n\nThe same high reactivity that makes 45S5 bioactive creates practical drawbacks. Its rapid degradation rate can produce gap formation between the material and host tissues, and the leakage of Na⁺ and Ca²⁺ can raise local pH enough to induce cytotoxic effects and delay hydroxyapatite formation[16](https://pmc.ncbi.nlm.nih.gov/articles/PMC6928922/). Its strong crystallization tendency limits hot-working into amorphous porous scaffolds; during sintering the powder tends to crystallize before it densifies, reducing bioactivity and mechanical strength[10](https://pmc.ncbi.nlm.nih.gov/articles/PMC11826416/) • [17](https://pmc.ncbi.nlm.nih.gov/articles/PMC10459405/). [Fracture toughness](https://www.edgepedia.org/fracture-toughness) of roughly 0.7–0.9 MPa·m½ falls well short of cortical bone (about 2–6 MPa·m½), which restricts use in load-bearing sites[4](https://www.spandidos-publications.com/10.3892/wasj.2026.476). These limits have motivated derivative compositions, such as 13-93, which adds K₂O and MgO and has higher silica content for improved high-temperature processing[18](https://pmc.ncbi.nlm.nih.gov/articles/PMC3085647/), and substitutions of Na₂O with alkaline earth oxides such as Mg and Sr to improve sinterability while maintaining biocompatibility[17](https://pmc.ncbi.nlm.nih.gov/articles/PMC10459405/).\n\n## Legacy\n\nBioglass was the first synthesized material that interacted with the body to initiate healing rather than merely being tolerated, a shift that helped give rise to the field now known as regenerative medicine[7](https://mse.ufl.edu/larry-hench-inventor-of-bioglass-and-childrens-author-dies-at-age-77/). Hench described tissue regeneration through the gene-activation properties of Bioglass's ionic dissolution products as a third generation of biomaterials, after bio-inert first-generation and bonding second-generation materials[3](https://pubmed.ncbi.nlm.nih.gov/17122907/). More than 1,000 publications have described 45S5 and its performance in vitro and in vivo in the 45 years after its discovery[19](https://www.sciencedirect.com/science/article/abs/pii/S0022309315000034).\n\n## References\n\n1. [Bioglass: A novel biocompatible innovation, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC3696226/)\n2. [Mesoporous Bioactive Glasses Cytocompatibility Assessment: A Review of In Vitro Studies, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC7839003/)\n3. [L. L. Hench (2006). The story of Bioglass. J Mater Sci Mater Med 17:967–978.](https://pubmed.ncbi.nlm.nih.gov/17122907/)\n4. [Gorassini et al. Bioglass 45S5 in dentistry: Current evidence, clinical applications and future perspectives. World Academy of Sciences Journal.](https://www.spandidos-publications.com/10.3892/wasj.2026.476)\n5. [Hench, Splinter, Allen, Greenlee (1971). Bonding mechanisms at the interface of ceramic prosthetic materials. J Biomed Mater Res 5:117–141.](https://onlinelibrary.wiley.com/doi/10.1002/jbm.820050611)\n6. [Bioactive Glass Applications: A Literature Review of Human Clinical Trials, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC8470635/)\n7. [Bioglass Inventor Larry Hench Dies at Age 77, University of Florida Department of Materials Science & Engineering](https://mse.ufl.edu/larry-hench-inventor-of-bioglass-and-childrens-author-dies-at-age-77/)\n8. [Effect of Thermal Treatments and Ion Substitution on Sintering and Crystallization of Bioactive Glasses: A Review, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC10342775/)\n9. [Mechanism of bioactivity (thesis chapter), Carnegie Mellon archive](https://archive.lib.cmu.ac.th/full/T/2013/mat40513wl_ch2.pdf)\n10. [Glasses for bone regeneration: structural features controlling physical properties and ion release of bioactive glasses 45S5, S53P4 and 13-93, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC11826416/)\n11. [Bioactive restorative materials in dentistry: a comprehensive review, Odontology (Springer)](https://link.springer.com/article/10.1007/s10266-025-01162-w)\n12. [Bioactive glass for periodontal regeneration: a systematic review, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC10169491/)\n13. [Bioactive Glasses: From Parent 45S5 Composition to Scaffold-Assisted Tissue-Healing Therapies, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC5872110/)\n14. [FDA 510(k) Summary K053387, PerioGlas – Bone Graft Particulate](https://www.accessdata.fda.gov/cdrh_docs/pdf5/K053387.pdf)\n15. [Current Development in Biomaterials—Hydroxyapatite and Bioglass for Applications in Biomedical Field: A Review, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC9680477/)\n16. [Bioactive Glass Applications in Dentistry, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC6928922/)\n17. [Advanced Bioactive Glasses: The Newest Achievements and Breakthroughs in the Area, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC10459405/)\n18. [Bioactive glass in tissue engineering, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC3085647/)\n19. [Bioglass: 10 milestones from concept to commerce, ScienceDirect](https://www.sciencedirect.com/science/article/abs/pii/S0022309315000034)\n20. [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/11205439/)\n\n---\n*Topic: Encyclopedia › Technology and the built world › Engineering and manufacturing › Materials science and metallurgy › Ceramics, glass, and minerals › Bioceramics and dental cements*\n\n*Initially written Oct 15, 2026*\n\n*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*\n\nLicense: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license\n", "same_as": [], "url": "https://www.edgepedia.org/bioglass-45s5", "markdown_url": "https://www.edgepedia.org/bioglass-45s5.md", "license": { "name": "Edgepedia Community License 1.0", "url": "https://www.edgepedia.org/edgepedia/license", "summary": "Free with credit, commercial use included. AI training is open to everyone. For other uses, organizations over USD 100M in revenue or 100M monthly users license separately.", "spdx": "LicenseRef-Edgepedia-Community-1.0" }, "credit": "\"Bioglass 45S5\", Edgepedia (EdgeChat), https://www.edgepedia.org/bioglass-45s5. Edgepedia Community License 1.0.", "credit_md": "\"[Bioglass 45S5](https://www.edgepedia.org/bioglass-45s5)\", Edgepedia (EdgeChat), [https://www.edgepedia.org/bioglass-45s5](https://www.edgepedia.org/bioglass-45s5). [Edgepedia Community License 1.0](https://www.edgepedia.org/edgepedia/license).", "credit_html": "\"Bioglass 45S5\", Edgepedia (EdgeChat), https://www.edgepedia.org/bioglass-45s5. Edgepedia Community License 1.0.", "speakable": "Bioglass 45S5 is a silicate bioactive glass discovered in 1969 by Larry L. Hench, the first synthetic material shown to bond directly with living bone." }