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Precipitation of an apatite layer on the surface of bioactive materials is considered an important step in the bone healing procedure. Wollastonite (CaSiO 3) bioglass has been recently employed as a bone replacement material and also, a carrier for targeted drug delivery. Regarding the impact of a material structure on its biological activity, to achieve the 100 % clinical success, realizing the material crystallinity and bone bonding potential can be important. Therefore, this study tried to prepare pure wollastonite (WS) nano-powders (<20 nm) via an easy and fast hydrothermal process. Different quantities (5, 10 and 15 wt%) of the amorphous and crystalline particles have been added to polycaprolactone (PCL) to obtain composite films via a simple solvent casting technique. The in-vitro bioactivity of the prepared particles as well as composite films was studied by placing the samples in the simulated body fluid (SBF) for 21 days. The physicochemical and microstructural properties of the products were then characterized by XRD, FTIR, FESEM, EDS and TEM. Moreover, the influence of the crystallinity on the bioactivity of the synthesized nanoparticles and also the obtained composite films was investigated for the first time. The results indicated that the amorphous bioglass and the surface of composite containing 15 wt% WS were completely covered by a thick bone-like apatite layer Therefore, these findings revealed that the prepared composite films composed of amorphous WS could be regarded as promising bioactive candidates for bone filling applications. [ABSTRACT FROM AUTHOR]

In this study new compounds consisting of activated carbon cloths (ACC) modified with calcium silicate (CaSiO3) were prepared for hydroxyapatite (HAP) generation. ACC samples were oxidized with 8 M HNO3 at different times (15 min and 2 h), to increase oxygenated functional groups. The CaSiO3 fine powders were prepared by chemical coprecipitation using Ca(NO3)2∙4H2O and Si(OC2H5)4, and 5 M NaOH was used as precipitant. The resulting powders were mixed with ethanol by ultrasound stirring and the previously oxidized activated carbon fibers were placed leaving under stirring for 30 min to allow particle dispersion. Once the formed compounds were dried, the samples were immersed in a simulated body fluid (SBF) solution for 21 days in conical tubes at 36.5 °C to allow the HAP formation on the ACC/CaSiO3 composite surface. The results indicated that the increase in oxidation time improves HAP formation on the surface from ACC/CaSiO3 compounds and this bioactive composite may be a potential material for bone regeneration.

In the maxillofacial area, specifically the orbital floor, injuries can cause bone deformities in the head and face that are difficult to repair or regenerate. Treatment methodologies include use of polymers, metal, ceramics on their own and in combinations mainly for repair purposes, but little attention has been paid to identify suitable materials for orbital floor regeneration. Polyurethane (PU) and hydroxyapatite (HA) micro- or nano- sized with different percentages (25%, 40% & 60%) were used to fabricate bioactive tissue engineering (TE) scaffolds using solvent casting and particulate leaching methods. Mechanical and physical characterisation of TE scaffolds was investigated by tensile tests and SEM respectively. Chemical and structural properties of PU and PU/HA scaffolds were evaluated by infrared (IR) spectroscopy and Surface properties of the bioactive scaffold were analysed using attenuated total reflectance (ATR) sampling accessory coupled with IR. Cell viability, collagen formed, VEGF protein amount and vascularisation of bioactive TE scaffold were studied. IR characterisation confirmed the integration of HA in composite scaffolds, while ATR confirmed the significant amount of HA present at the top surface of the scaffold, which was a primary objective. The SEM images confirmed the pores' interconnectivity. Increasing the content of HA up to 40% led to an improvement in mechanical properties, and the incorporation of nano-HA was more promising than that of micro-HA. Cell viability assays (using MG63) confirmed biocompatibility and CAM assays confirmed vascularization, demonstrating that HA enhances vascularization. These properties make the resulting biomaterials very useful for orbital floor repair and regeneration. [ABSTRACT FROM AUTHOR]

Abstract Background The purpose of this in vitro study is to compare the antimicrobial effect and pH of two calcium silicate cements Mineral trioxide aggregate high plasticity (Angelus PR, Brazil) and iRoot BP Plus (BioCeramix Inc., Vancouver, BC, Canada) and new bioactive restorative resin composite restorative material (ACTIVA, MA, Pulpdent, USA) against aerobic bacteria, strictly anaerobic bacteria and a yeast by using an agar diffusion test. Methods The materials were tested immediately after manipulation and were applied to the agar plates. Sodium hypochlorite (NaOCl) 5.25% was used as a positive control group. The dry filter paper acted as a negative control group for this study. The size of the inhibition zone for each material was measured after 12, 24 and 48 h. At the time of pH measurement; materials were prepared, crushed then dispersed in distilled water. Results The one-way Anova test revealed that iRoot BP Plus significantly showed superior antimicrobial efficacy compared to MTA-HP against the following species; Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, Enterococcus faecium, Peptostreptococcus anaerobius and Candida albicans (P

Bioactive and biodegradable scaffolds that mimic the natural extracellular matrix of bone serve as temporary structures to guide new bone tissue growth. In this study, 3D-printed scaffolds composed of poly (lactic acid) (PLA)-tricalcium phosphate (TCP) (90-10 wt.%) were modified with 1%, 5%, and 10 wt.% of ZnO to enhance bone tissue regeneration. A commercial chain extender named Joncryl was incorporated alongside ZnO to ensure the printability of the composites. Filaments were manufactured using a twin-screw extruder and subsequently used to print 3D scaffolds via fused filament fabrication (FFF). The scaffolds exhibited a homogeneous distribution of ZnO and TCP particles, a reproducible structure with 300 μm pores, and mechanical properties suitable for bone tissue engineering, with an elastic modulus around 100 MPa. The addition of ZnO resulted in enhanced surface roughness on the scaffolds, particularly for ZnO microparticles, achieving values up to 241 nm. This rougher topography was responsible for enhancing protein adsorption on the scaffolds, with an increase of up to 85% compared to the PLA-TCP matrix. Biological analyses demonstrated that the presence of ZnO promotes mesenchymal stem cell (MSC) proliferation and differentiation into osteoblasts. Alkaline phosphatase (ALP) activity, an important indicator of early osteogenic differentiation, increased up to 29%. The PLA-TCP composite containing 5% ZnO microparticles exhibited an optimized degradation rate and enhanced bioactivity, indicating its promising potential for bone repair applications., (© 2024 IOP Publishing Ltd.)

Objectives: This study aimed to evaluate the clinical performance of an alkasite restorative material in molars that had undergone root canal treatment., Materials and Methods: The research was registered in Brazilian Registry of Clinical Trials. The randomized clinical trial involved 33 patients, each with at least 1 mandibular molar requiring restoration after receiving endodontic treatment. Patients were randomly assigned to receive either bulk-fill resin composite (Tetric N Ceram Bulk Fill, Ivoclar Vivadent) or the alkasite restorative material (Cention N, Ivoclar Vivadent). Upon completion of the restorations, 3 calibrated professionals utilized the United States Public Health Service criteria to assess various factors, including retention, secondary caries, marginal adaptation, restoration color, marginal pigmentation, and anatomical form. Evaluations were conducted at intervals of 7 days, 6 months, and 17 months. Additionally, the assessment encompassed the presence of radiolucent lines adjacent to the restoration, material deficiencies or excess, contact points, and caries recurrence. The data underwent analysis using the Friedman and Mann-Whitney tests (α = 0.05)., Results: After 17 months, the results revealed that the alkasite restorative material exhibited greater wear of anatomical shape compared to the bulk-fill resin composite ( p = 0.0189). Furthermore, the alkasite restorative material significantly differed from the natural tooth color in most cases ( p = 0.0000). However, no other criteria displayed significant differences between the materials or over time ( p > 0.05)., Conclusions: The alkasite restorative material (Cention N) emerges as a viable option for restoring endodontically treated teeth, displaying clinically acceptable alterations after a 17-month evaluation period., Trial Registration: Brazilian Registry of Clinical Trials (ReBEC) Identifier: RBR-97kx5jv., Competing Interests: Conflict of Interest: No potential conflict of interest relevant to this article was reported., (Copyright © 2024. The Korean Academy of Conservative Dentistry.)

In the maxillofacial area, specifically the orbital floor, injuries can cause bone deformities in the head and face that are difficult to repair or regenerate. Treatment methodologies include use of polymers, metal, ceramics on their own and in combinations mainly for repair purposes, but little attention has been paid to identify suitable materials for orbital floor regeneration. Polyurethane (PU) and hydroxyapatite (HA) micro- or nano- sized with different percentages (25%, 40% & 60%) were used to fabricate bioactive tissue engineering (TE) scaffolds using solvent casting and particulate leaching methods. Mechanical and physical characterisation of TE scaffolds was investigated by tensile tests and SEM respectively. Chemical and structural properties of PU and PU/HA scaffolds were evaluated by infrared (IR) spectroscopy and Surface properties of the bioactive scaffold were analysed using attenuated total reflectance (ATR) sampling accessory coupled with IR. Cell viability, collagen formed, VEGF protein amount and vascularisation of bioactive TE scaffold were studied. IR characterisation confirmed the integration of HA in composite scaffolds, while ATR confirmed the significant amount of HA present at the top surface of the scaffold, which was a primary objective. The SEM images confirmed the pores’ interconnectivity. Increasing the content of HA up to 40% led to an improvement in mechanical properties, and the incorporation of nano-HA was more promising than that of micro-HA. Cell viability assays (using MG63) confirmed biocompatibility and CAM assays confirmed vascularization, demonstrating that HA enhances vascularization. These properties make the resulting biomaterials very useful for orbital floor repair and regeneration.

Aim: This laboratory study aimed to investigate the effects of three endodontic biomaterials; MTA‐HP, iRoot‐BP‐Plus and ACTIVA on the proliferation, adhesion and osteogenic differentiation of human Dental Pulp Stem Cells (hDPSCs). Methodology: The hDPSCs were isolated from the dental pulps of 21 patients scheduled for surgical extraction of their impacted third molars. The MTT assay was used for assessing cellular proliferation. Ninety‐six‐well plates were used and the experiment was repeated four times under the same condition and the assay was done in triplicate. Four groups were assigned in which the hDPSCs were cultured in complete media only and considered as negative control. Whilst in the 2nd, 3rd and 4th groups, the cells were treated with CM supplemented with 1.5 μl MTA‐HP (CM‐MTA, iRoot‐BP‐Plus (CM‐BP), and ACTIVA(CM‐AC) extracts, respectively. Attachment adhesion and growth morphology of hDPSCs were observed using SEM and the osteogenic differentiation assay was evaluated by Alizarin red stain test (ARS). The data of proliferation and osteogenic differentiation were analysed using two‐way ANOVA followed by Tukey's post hoc multiple comparison test. A p‐value < 0.05 was considered significant to analyse the differences amongst the means of groups. Results: Both CM‐MTA and CM‐BP groups were associated with a significant increase in hDPSC proliferation in comparison with CM‐AC and CM groups (p = 0.001). hDPSCs exhibited a greater cellular attachment to iRoot‐BP‐Plus surfaces followed by MTA‐HP, whilst less attachment was observed in the ACTIVA group. Moreover, at day 7 there was a significant difference in formation of mineralizing nodules; CM‐BP, CM‐MTA and CM‐AC groups respectively (p = 0.001). Whilst there was no significance of difference between CM‐AC and CM groups (p > 0.05). Conclusions: In a laboratory setting, ACTIVA, MTA‐HP and iRoot‐BP‐Plus promoted hDPSCs proliferation, mineralization and attachment, which may explain their in‐situ success as endodontic biomaterials. [ABSTRACT FROM AUTHOR]

Biologically active extract was obtained from the leaves of Anoectochilus formosanus Hayata plants grown in vitro, and the composite was prepared by adsorption/precipitation of this extract components on the fumed silica surface under fluidized bed conditions. The composite was characterized by means of ultraviolet–visible and Fourier transform infrared spectroscopy, thermogravimetric analysis–derivative thermogravimetric analysis, scanning electron microscopy, and nitrogen adsorption method. Antioxidant properties of the extract and the composite were studied using Folin–Ciocalteu method and 2,2-diphenyl-1-picrylhydrazyl (DPPH) test; nitric oxide radical and hydroxyl radical scavenging activities of the extract and the composite were also evaluated. It was shown that adsorption/precipitation of phytochemicals does not significantly affect the texture of silica powder, while the presence of silica does not reduce the antioxidant ability of the extract components. At the same time, inclusion in the composite was found to provide bioactive substances with elongated effect and enhanced storage stability; caking resistance of silica particles was improved, as well. [ABSTRACT FROM AUTHOR]

Abstract Background The purpose of this study was to compare the biocompatibility of three bioactive materials, namely ACTIVA bioactive restorative resin composite, iRoot BP plus and Mineral Trioxide Aggregate (MTA) Angelus-HP. Methods Seventy-five Wistar male rats were subjected to subcutaneous implantation of four polyethylene tubes; one empty tube was used as control (Group 1), and the other tubes were filled with ACTIVA (Group 2), iRoot BP (Group 3) and MTA-HP (Group 4). Then, the rats were subdivided into 3 groups according to the sacrification time into one, two and 4 weeks (n = 25 rats). Tissue specimens were submitted to histopathological and immunohistochemical analysis of α-SMA and caspase 3. Results The one-way Anova test revealed that ACTIVA group exhibited minimal inflammation in comparison to calcium silicate cements (iRoot BP and MTA-HP groups). iRoot BP group significantly revealed a more severe degree of chronic inflammation in comparison to other groups (P

The aim of this study was to evaluate water sorption and solubility of two series of experimental composites containing amorphous calcium phosphate (ACP) or bioactive glass (BG). Water sorption and solubility were measured for up to 287 days. The surface precipitation of calcium phosphates was evaluated by scanning electron microscopy. The ACP-series showed higher water sorption (223–568 μg/mm³) than the BG-series (40–232 μg/mm³). In contrast, the ACP-series had generally lower solubility (37–106 μg/mm³) than the BG-series (1–506 μg/mm³). The constant specimen mass for the ACP-series was attained after 14 days of water immersion, while the mass decrease due to long-term solubility in the BG-series lasted beyond 287 days. Calcium phosphates precipitated in composites with the BG filler loading of 10 wt% or more, as well as in all of the ACP-containing composites. The experimental composite series showed water sorption and solubility considerably higher than commercial materials. [ABSTRACT FROM AUTHOR]

The objectives were to investigate a novel combination of gene-knockout with antimicrobial dimethylaminohexadecyl methacrylate (DMAHDM) composite in regulating oral biofilm from a cariogenic state toward a non-cariogenic state. A tri-species biofilm model included cariogenic Streptococcus mutans (S. mutans), and non-cariogenic Streptococcus sanguinis (S. sanguinis) and Streptococcus gordonii (S. gordonii). Biofilm colony-forming-units (CFUs), lactic acid and polysaccharide production were measured. TaqMan real-time-polymerase-chain reaction was used to determine the percentage of each species in biofilm. The rnc gene-knockout for S. mutans with DMAHDM composite reduced biofilm CFU by five logs, compared to control (p < 0.05). Using parent S. mutans, an overwhelming S. mutans percentage of 68.99% and 69.00% existed in biofilms on commercial composite and 0% DMAHDM composite, respectively. In sharp contrast, with a combination of S. mutans rnc knockout and DMAHDM composite, the cariogenic S. mutans percentage in biofilm was reduced to only 6.33%. Meanwhile, the non-cariogenic S. sanguinis + S. gordonii percentage was increased to 93.67%. Therefore, combining rnc-knockout with bioactive and therapeutic dental composite achieved the greatest reduction in S. mutans, and the greatest increase in non-cariogenic species, thereby yielding the least lactic acid-production. This novel method is promising to obtain wide applications to regulate biofilms and inhibit dental caries.

Background: Nanotechnology can be defined as the science involved in the design, synthesis, characterization, and application of materials and devices whose smallest functional organization in at least one dimension is on the nanometer scale. Aim: The aim of this cross-sectional study was to assess the knowledge and attitude of dental students and intern practitioners about the nanotechnology in dentistry at KSA. Materials and methods: An online questionnaire was distributed through the link shared to dental students and intern practitioners via social networking websites. A simple random sample comprised of 306 participants almost distributed across the five geographical regions of Saudi Arabia. The questionnaire was designed to obtain information about the basic knowledge and attitude about nanotechnology being used worldwide for better dental treatment. It consisted of two parts: Part A: Biographic and demographic data of the participants. Part B: Knowledge and Attitude towards nanotechnology in dentistry was focused. Statistical analysis of the data was performed. Frequency distribution and Chi-square analysis were used to determine if there were any relationships and statistically significant differences between knowledge and attitude of nanotechnology in dentistry with biographic and demographic factors. Results: Out of the 306 participants' response, 213 (69.3%) had heard about the nanotechnology and the main source of information about nanotechnology in dentistry was Internet (32.1%). Only (26.4%) of participates use nanomaterial in their university and (73.6%) didn't use it. (52.1%) of them strongly disagree with nanotechnology will have a wide application in future. Conclusion: This study revealed that there is lack of awareness on Nanotechnology application in dentistry among the dental students and intern practitioners at Saudi Arabia. [ABSTRACT FROM AUTHOR]

Medical polymers of biostable nature ( e.g. polymethylmetacrylate, PMMA) are widely used in various clinical applications. In this study, novel PMMA-based composite bone cement was prepared. Bioactive glass (BAG) particulate filler (30 wt%) was added to enhance potentially the integration of bone to the cement. The polymer matrix was functionalized with trimethoxysilyl to achieve an interfacial bond between the matrix and the fillers of BAG. The amount of trimethoxysilyl in the monomer system varied from 0 to 75 wt%. The effects of dry and wet (simulated body fluid, SBF at +37 °C for 5 weeks) conditions were investigated. In total, 20 groups of specimens were prepared. The specimens were subjected to a destructive mechanical test in compression. Scanning electron microscopy (SEM) and micro-computed tomography (micro-CT) were used to study the surface and the three-dimensional morphology of the specimens. The results of the study indicated that the addition of trimethoxysilyl groups led to the formation of a hybrid polymer matrix which, in lower amounts (<10 wt% of total weight), did not significantly affect the compression properties. However, when the specimens stored in dry and wet conditions were compared, the water sorption increased the compression strength (~5–10 MPa per test group). At the same time, the water sorption also caused an evident porous structure formation for the specimens containing BAG and siloxane formation in the hybrid polymer matrix. [ABSTRACT FROM AUTHOR]

In this study new compounds consisting of activated carbon cloths (ACC) modified with calcium silicate (CaSiO 3 ) were prepared for hydroxyapatite (HAP) generation. ACC samples were oxidized with 8 M HNO 3 at different times (15 min and 2 h), to increase oxygenated functional groups. The CaSiO 3 fine powders were prepared by chemical coprecipitation using Ca(NO 3 ) 2 ∙4H 2 O and Si(OC 2 H 5 ) 4 , and 5 M NaOH was used as precipitant. The resulting powders were mixed with ethanol by ultrasound stirring and the previously oxidized activated carbon fibers were placed leaving under stirring for 30 min to allow particle dispersion. Once the formed compounds were dried, the samples were immersed in a simulated body fluid (SBF) solution for 21 days in conical tubes at 36.5 °C to allow the HAP formation on the ACC/CaSiO 3 composite surface. The results indicated that the increase in oxidation time improves HAP formation on the surface from ACC/CaSiO 3 compounds and this bioactive composite may be a potential material for bone regeneration., Competing Interests: The authors declare no conflict of interest., (© 2022 The Author(s).)

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Abstract: Silica nanoparticle reinforced poly (vinyl alcohol) cast sheets 40μm thick were tested for mechanical and biological properties. The films were characterized using X-ray diffraction, scanning electron microscopy, and infrared spectroscopy. The crystallinity decreased with increased silica content. Changes in the morphology and structure upon the addition of silica suggest the formation of cross-linking. The modulus increased from 300MPa for PVA to 7.2GPa for 120wt.% silica nanoparticle in the blend and the tensile strength increased from 3.5MPa to 35MPa. The modulus estimated using dynamic tests, tensile tests, and nanoindentation was comparable and was predicted well using the Halpin-Tsai's equation. The nanocomposites were an order of magnitude tougher than the pure polymer. Silica based nanocomposite was also found to be an excellent template for the deposition of calcium hydroxyapatite when immersed in simulated body fluid. The modulus and tensile strength of apatite coated silica nanoparticle (120wt.%)–PVA composite increased to 11GPa and 65MPa respectively, close to that of cortical bone. The results represent one of the largest increases in mechanical properties of nanocomposite mimicking the properties of human bone. The addition of silica can also aid in osseointegration. [Copyright &y& Elsevier]

Natural bone is a unique nanostructured material made of collagen fibre matrix and hydroxyapatite (HA) nanocrystals, providing mechanical support and protection from the vertebrate skeleton. However, in severe cases like bone-deficiencies, bone needs to be 'externally' repaired. Initially, different biological solutions were developed in bone-guided regeneration. However, due to the limitations with the existing biological grafts, a lot of researches have been devoted toward biomaterials including metals, ceramics, and polymers. On the basis of the interface reactions between the implant and the surrounding tissues, these biomaterials may be classified as 'nearly inert' or bioactive. Interestingly, the bioactive materials exhibit a specific biological response, leading to the formation of a natural bonding junction between the bone and the implant during bone regeneration. Recently, a special attention has been paid to a new generation of bioactive materials, i.e. (nano)structured biomaterials composed of a bioresorbable polymer matrix reinforced with bioactive inorganic compounds. While (bio)ceramic component provides the bioactivity, these materials can be readily engineered in such a way that their resorption rate in the body match the formation rate of the new tissue. This review hence reports the different biological and non-biological solutions developed in bone-guided regeneration, with a special emphasis on polymer-based materials, and our recent results obtained in osseointegration The bone physiology, and its natural regeneration are also described. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Self-hardening calcium phosphate cement (CPC) sets to form hydroxyapatite with high osteoconductivity, but its brittleness and low strength limit its use to only non-stress bearing locations. Previous studies developed bioactive composites containing hydroxyapatite fillers in Bis-GMA-based composites for bone repair applications, and they possessed higher strength values. However, these strengths were still lower than the strength of cortical bone. The aim of this study was to develop strong and bioactive composites by combining CPC fillers with nano-silica-fused whiskers in a resin matrix, and to characterize the mechanical properties and cell response. Silica particles were fused to silicon carbide whiskers to roughen the whisker surfaces for enhanced retention in the matrix. Mass ratios of whisker:CPC of 1:2, 1:1 and 2:1 were incorporated into a Bis-GMA-based resin and hardened by two-part chemical curing. Composite with only CPC fillers without whiskers served as a control. The specimens were tested using three-point flexure and nano-indentation. Composites with whisker:CPC ratios of 2:1 and 1:1 had flexural strengths (mean±SD; n=9) of (164±14) MPa and (139±22) MPa, respectively, nearly 3 times higher than (54±5) MPa of the control containing only CPC fillers (p<0.05). The strength of the new whisker-CPC composites was 3 times higher than the strength achieved in previous studies for conventional bioactive composites containing hydroxyapatite particles in Bis-GMA-based resins. The mechanical properties of the CPC-whisker composites nearly matched those of cortical bone and trabecular bone. Osteoblast-like cell adhesion, proliferation and viability were equivalent on the non-whisker control containing only CPC fillers, on the whisker composite at whisker:CPC of 1:1, and on the tissue culture polystyrene control, suggesting that the new CPC-whisker composite was non-cytotoxic. [Copyright &y& Elsevier]

Summary This study examined the morphological and compositional structure of bone–implant interfaces after in vivo implantation into the tibias of rabbits. The implants were composed of biodegradable polyhydroxybutyrate/polyhydroxyvalerate copolymer reinforced with synthetic hydroxyapatite (HA) particles. Optical and scanning electron microscopy techniques were used, including energy-dispersive X-ray analysis. The interface was found to be morphologically, biologically and chemically active throughout the period of study. There was a strong tendency to rebuild the bone structure at the interface after implantation, independent of the composition of the implant, but direct bone bonding with the implant depended on the bioactive nature of the interface, as represented by the HA particles. At all implantation times, lamellar bone formed at the interface and replaced degrading polymer matrix, while engulfing HA filler particles. In regions about 50–100 from the interface, the bone region displayed an osteon organization. Osteoblasts and osteocytes were identified throughout the interface region. The thickness of the newly formed bone significantly increased over the period of the experiment from about 130 µm at 1 month to about 770 µm at 6 months. Materials that behave in this manner may be useful in some bone replacement therapies. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate biologic behavior of a composite of bioactive glass (BAG) (S53P4) and copolymer of poly(&epsiv;-caprolactone-co-dl-lactide) in experimental bone defects in rabbits. Twenty New Zealand white rabbits were used for the study. Bone defects (4×6 mm) were prepared in the medial surfaces of the femoral condyles and the tibia. Cavities were filled with three different composites: composite with 60 wt% of small BAG granules (granule size <45 μm) and composites with 40 and 60 wt% of large BAG granules (granule size 90–315 μm). Copolymer without BAG was used as a reference material. Follow-up period was 8 and 16 weeks.In the femur at 8 weeks all the samples were partly surrounded by fibrous capsule. New bone formation was noticed in the areas where glass granules were in direct contact with the bone. At 16 weeks fibrous capsule was thinner in all samples. Bone ingrowth was found in the superficial layers of the composites with large glass granules. However, the percent of direct bone contact decreased between 8 and 16 weeks (p<0.05).In the tibia at 8 weeks all the samples showed fibrous encapsulation. At 16 weeks fibrous capsules were thinner or occasionally disappeared. Bone ingrowth was noticed in the samples with large glass granules. Further, new bone formation was found in the medullary cavity. No signs of polymer degradation were seen at any time point.It can be concluded that the composite of BAG (S53P4) and copolymer of poly(&epsiv;-caprolactone-co-dl-lactide) is biocompatible with the bone tissue within the 16 weeks implantation period. [Copyright &y& Elsevier]

In vitro bioactivity of composites of poly(&epsiv;-caprolactone-co-DL-lactide) P(CL/DL-LA) containing different amounts (40, 60 and 70 wt%) of bioactive glass, S53P4, was evaluated. Two ranges of granule size of bioactive glass (<45 μm and 90–315 μm) were blended with P(CL/DL-LA) copolymer in a batch mixer. The composites were characterised by dynamic mechanical thermal analysis. The molecular weight and the melting temperature of the copolymer matrix were adjusted to enable the application of the composite material by injection below 50°C. Formation of Ca-P deposition on the surface of the composites after dissolution in simulated body fluid at 37°C was recorded by scanning electron microscopy. Degradation of the composite material was measured by water absorption and changes in the average molecular weights as a function of the dissolution time. In vitro bioactivity was found to be dependent on the weight fraction and granule size range of the bioactive glass used. The presence of the bioactive filler also accelerated the degradation compared with the neat polymer sample. [Copyright &y& Elsevier]