Crystallographic plane-induced selective mineralization of nanohydroxyapatite on fibrous-grained titanium promotes osteointegration and biocorrosion resistance.

The (002) crystallographic plane-oriented hydroxyapatite (HA) and anatase TiO2 enable favorable hydrophilicity, osteogenesis, and biocorrosion resistance. Thus, the crystallographic plane control in HA coating and crystalline phase control in TiO2 is vital to affect the surface and interface bioactivity and biocorrosion resistance of titanium (Ti) implants. However, a corresponding facile and efficient fabrication method is absent to realize the HA(002) mineralization and anatase TiO2 formation on Ti. Herein, we utilized the predominant Ti(0002) plane of the fibrous-grained titanium (FG Ti) to naturally form anatase TiO2 and further achieve a (002) basal plane oriented nanoHA (nHA) film through an in situ mild hydrothermal growth strategy. The formed FG Ti-nHA(002) remarkably improved hydrophilicity, mineralization, and biocorrosion resistance. Moreover, the nHA(002) film reserved the microgroove-like topological structure on FG Ti. It could enhance osteogenic differentiation through promoted contact guidance, showing one order of magnitude higher expression of osteogenic-related genes. On the other hand, the nHA(002) film restrained the osteoclast activity by blocking actin ring formation. Based on these capacities, FG Ti-nHA(002) improved new bone growth and binding strength in rabbit femur implantation, achieving satisfactory osseointegration within 2 weeks.

Programmed surface platform orchestrates anti-bacterial ability and time-sequential bone healing for implant-associated infection.

Implant-associated infection (IAI) has become an intractable challenge in clinic. The healing of IAI is a complex physiological process involving a series of spatiotemporal connected events. However, existing titanium-based implants in clinic suffer from poor antibacterial effect and single function. Herein, a versatile surface platform based on the presentation of sequential function is developed. Fabrication of titania nanotubes and poly-γ-glutamic acid (γ-PGA) achieves the efficient incorporation of silver ions (Ag+) and the pH-sensitive release in response to acidic bone infection microenvironment. The optimized PGA/Ag platform exhibits satisfactory biocompatibility and converts macrophages from pro-inflammatory M1 to pro-healing M2 phenotype during the subsequent healing stage, which creates a beneficial osteoimmune microenvironment and promotes angio/osteogenesis. Furthermore, the PGA/Ag platform mediates osteoblast/osteoclast coupling through inhibiting CCL3/CCR1 signaling. These biological effects synergistically improve osseointegration under bacterial infection in vivo, matching the healing process of IAI. Overall, the novel integrated PGA/Ag surface platform proposed in this study fulfills function cascades under pathological state and shows great potential in IAI therapy.

Analysis of osseointegration of implants with macrogeometries with healing chambers: a randomized clinical trial.

BACKGROUND: To verify the influence of macrogeometry with healing chambers on the osseointegration of dental implants by analyzing implant stability quotient (ISQ) and evaluate the correlation between insertion torque and ISQ insertion with different macrogeometries. METHODS: In total, 26 implants were installed in the posterior mandible of eight patients with sufficient bone height for the installation of implants measuring 3.5 mm in diameter and 9.0 mm in length. The implants were categorized according to two types of macrogeometry: a test group (GT) with 13 conical implants with healing chambers and a control group (GC) with 13 conical implants with conventional threads. To insert the implants, a bone drilling protocol was used up to a diameter of 3 mm with the last helical bur. The insertion torque of the implants was evaluated, followed by the measurement of ISQ at 0 (T-0), 7 (T-7), 14 (T-14), 21 (T-21), 28 (T-28), and 42 (T-42) days. RESULTS: The mean insertion torque was 43 Ncm in both groups, without a significant difference. Moreover, no significant difference in the ISQ values was found between the groups at different time points (p > 0.05), except at T-7 (GT = 69.87±1.89 and GC = 66.48±4.49; p = 0.01). Although there was no significant difference, ISQ median values were higher in the GT group than GC group at 28 days (GT = 67.98 and GC = 63.46; p = 0.05) and 42 days (GT = 66.12 and GC = 60.33; p = 0.09). No correlation was found between the insertion torque and ISQ insertion (p > 0.05). CONCLUSION: Furthermore, implants with a 3.5 mm diameter macrogeometry, with or without healing chambers, inserted with a drilling protocol up to 3 mm in diameter of the last helical bur, led to a similar secondary stability, with no difference in ISQ values. Although, implants with healing chamber demonstrates ascending values in the graph of ISQ, having a trend of faster osseointegration than implants without healing chambers. Both macrogeometries provide a similar primary stability to implants. TRIAL REGISTRATION: This study was registered retrospectively in ReBec (brazilian registry of clinical trials) under the number RBR-96n5×69, on the date of 19/06/2023.

Histological and scanning electron microscopy investigation of the effects of titanium surface modifications on osseointegration in rabbits.

This study aimed to compare the novel Estas Medical Anodization (EMA) surface treatment technique with the techniques commonly used in the literature and to examine their effects on osteointegration in the rabbit tibia. A total of 24 rabbits used in this study were divided into 3 groups, with 8 rabbits in each group. Using both tibias of all rabbits in the study, screws belonging to the control group were placed in the left tibia, and the right tibia belonging to the experimental group were placed. In the first 8 rabbits, a single experimental group in the right tibia were used; in the second 8 rabbits, 2 different experimental groups in the right tibia were used; and in the last 8 rabbits, 2 different experimental groups in the right tibia were used. Thus, 5 different experimental groups with 8 screws in each group and a separate control group were formed for each of them. EMA-treated surfaces were named 200-800 nm iris oxidation and 800-1200 nm gray oxidation according to the TiO2 layer thickness. Group 1 was implanted with mini-screws prepared with chemical etching+EMA iris oxidation, while group 2 was implanted with sandblasted, large-grit and acid-etched (SLA) mini screws treated with EMA gray oxidation. Group 3 was implanted with mini-screws treated with EMA gray oxidation, group 4 was implanted with mini-screws treated with chemical etching+micro-arc oxidation, and group 5 was implanted with mini-screws treated with chemical etching+EMA gray oxidation. The control group was implanted with mini-screws prepared with pure titanium. At the end of 6 weeks, osseointegration percentages were calculated and compared using histological and scanning electron microscope (SEM) analyses. The histological results confirmed the increase in osseointegration percentages in all experimental groups compared to those that received pure titanium implants (P values control group vs group 1=.005, control group vs group 2, 3, 4, 5=.001). The comparison between the groups revealed that the chemical etching+EMA gray oxidation modification technique (group 5) significantly increased osseointegration compared to the SLA+EMA gray oxidation technique (group 5 vs group 2 P=.016) and the chemical etching+EMA iris oxidation technique (group 5 vs group 1 Pp=.001). The EMA gray oxidation technique (group 3) significantly increased osseointegration compared to the chemical etching+EMA iris oxidation technique (group 1) (group 3 vs group 1 P=.043). The results of the SEM analysis showed that osseointegration was significantly increased in all experimental groups compared to that in the pure titanium (control) group (P values control group vs group 1, 2, 3=.001, control group vs Group 4,5=.006). The mean osseointegration percentage in the experimental groups was the highest in group 5, followed by group 4, group 3 and group 1 equally, and group 2. However, the differences among the experimental were not significant (group 1, group 2, group 3, group 4 vs group 5 P=.408). The EMA titanium surface modification techniques we developed significantly increased osseointegration compared to the pure titanium surface. The EMA gray oxidation technique seems to result in higher osseointegration rates than the EMA iris oxidation technique, and similar rates can be found with the SLA and chemical etching techniques. N/A.

Clinical and histological efficacy of a new implant surface in achieving early and stable osseointegration: An in vivo study.

An advantage of treated implant surfaces is their increased degree of hydrophilicity and wettability compared with untreated, machined, smooth surfaces that are hydrophobic. The present preclinical in vivo study aimed to compare the two implant surface types, namely SLActive (Straumann, Basel, Switzerland) and nanohydroxyapatite (Hiossen, Englewood Cliffs, NJ, USA), in achieving early osseointegration. The authors hypothesised that the nanohydroxyapatite surface is comparable to SLActive for early bone-implant contact. Six male mixed foxhounds underwent mandibular premolar and first molar extraction, and the sockets healed for 42 days. The mandibles were randomised to receive implants with either SLActive (control group) or nanohydroxyapatite surfaces (test group). A total of 36 implants were placed in 6 animals, and they were sacrificed at 2 weeks (2 animals), 4 weeks (2 animals) and 6 weeks (2 animals) after implant surgery. When radiographic analysis was performed, the difference in bone level between the two groups was statistically significant at 4 weeks (P = 0.024) and 6 weeks (P = 0.008), indicating that the crestal bone level was better maintained for the test group versus the control group. The bone-implant contact was also higher for the test group at 2 (P = 0.012) and 4 weeks (P = 0.011), indicating early osseointegration. In conclusion, this study underscored the potential of implants with nanohydroxyapatite surfaces to achieve early osseointegration.

Osseointegration and Histopathological Evaluation of Titanium-Titanium Diboride Composite Compared to Pure Titanium Implant Materials Prepared by Powder Metallurgy (In Vivo Study).

The efficacy and osseointegration rate of an implant depend on its biocompatibility. Modern implantology seeks fast and reliable osseointegration, which is essential for clinical success. The objective of this research was to assess the osseointegration and biocompatibility of a titanium-titanium diboride composite (Ti-TiB2) in rabbits in contrast to those of pure titanium (Ti). A total of 64 cylindrical implant specimens were fabricated, consisting of two sets: pure Ti (32 implants) and Ti-TiB2 composite (32 implants). In this study, two implants were implanted per tibia (left and right tibias) in 16 white male New Zealand rabbits, for a total of four implants per rabbit (4 × 16 = 64 implants). A pushout test was used to assess implant specimen-bone bonding after 2 and 6 weeks of healing. The experiment utilized five rabbits per healing phase, which means that 20 implants per time point were used for the pushout tests. (10 for pure Ti and 10 for the composite). Histology was used to examine the tissue response to biocompatibility, and histomorphometry was used to measure new bone growth at the two time points. With three rabbits per time point, 12 implants were employed for the histological analyses. After implantation, the pushout shear strength results revealed that the mean shear strength of the Ti-TiB2 implant specimens (5.4 ± 0.029 MPa for 2 weeks, 7.9 ± 0.029 MPa for 6 weeks) was statistically greater (p < 0.0001) than that of the pure Ti implant specimens (5.1 ± 0.015 MPa for 2 weeks, 6.6 ± 0.047 MPa for 6 weeks). After 2 weeks, woven bone tissues were observed around the pure titanium implants, and active osteoid tissue around the composite implants exhibited significant differences in new bone formation areas (NBFAs) (0.54 ± 0.004 mm2 for Ti and 0.65 ± 0.003 mm2 for the composite). After 6 weeks, there was new bone formation with osteocytes around the pure titanium implants (NBFA of 2.44 mm2) and osteoid maturation with the observation of reversal lines around the composite implants (NBFA of 2.89 mm2). The developed Ti-TiB2 material was biocompatible and demonstrated superior bone growth compared to that of the pure Ti materials after 2 and 6 weeks.

Titanium micro-nano textured surface with strontium incorporation improves osseointegration: an in vivo and in vitro study.

OBJECTIVES: This study aimed to investigate the osseointegration of titanium (Ti) implants with micro-nano textured surfaces functionalized with strontium additions (Sr) in a pre-clinical rat tibia model. METHODOLOGY: Ti commercially pure (cp-Ti) implants were installed bilaterally in the tibia of 64 Holtzman rats, divided into four experimental groups (n=16/group): (1) Machined surface - control (C); (2) Micro-nano textured surface treatment (MN); (3) Micro-nano textured surface with Sr2+ addition (MNSr); and (4) Micro-nano textured surface with a higher complementary addition of Sr2+ (MNSr+). In total, two experimental euthanasia periods were assessed at 15 and 45 days (n=8/period). The tibia was subjected to micro-computed tomography (µ-CT), histomorphometry with the EXAKT system, removal torque (TR) testing, and gene expression analysis by PCR-Array of 84 osteogenic markers. Gene expression and protein production of bone markers were performed in an in vitro model with MC3T3-E1 cells. The surface characteristics of the implants were evaluated by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and laser scanning confocal microscopy. RESULTS: SEM, confocal, and EDS analyses demonstrated the formation of uniform micro-nano textured surfaces in the MN group and Sr addition in the MNSr and MNSr+ groups. TR test indicated greater osseointegration in the 45-day period for treated surfaces. Histological analysis highlighted the benefits of the treatments, especially in cortical bone, in which an increase in bone-implant contact was found in groups MN (15 days) and MNSr (45 days) compared to the control group. Gene expression analysis of osteogenic activity markers showed modulation of various osteogenesis-related genes. According to the in vitro model, RT-qPCR and ELISA demonstrated that the treatments favored gene expression and production of osteoblastic differentiation markers. CONCLUSIONS: Micro-nano textured surface and Sr addition can effectively improve and accelerate implant osseointegration and is, therefore, an attractive approach to modifying titanium implant surfaces with significant potential in clinical practice.

Primary stability with osseodensification drilling of dental implants in the posterior maxilla region in humans: A systematic review.

Currently, a new non-subtractive drilling technique, called osseodensification (OD), has been developed. It involves using specially designed drills with large negative cutting angles that rotate counterclockwise, causing expansion through plastic bone deformation, thus compacting the autologous bone to the osteotomy walls, which improves the primary stability of the implant.The present systematic review aimed to determine whether the OD technique can increase the primary stability of dental implants in the posterior maxilla region as compared to the conventional drilling (CD) technique.Five databases were searched up to June 30, 2022. The inclusion criteria embraced observational clinical studies, randomized and non-randomized controlled trials, human studies in vivo, comparing OD and CD, with the measurement of the primary stability of implants in the posterior maxilla region by means of the implant stability quotient (ISQ). The tools used to assess the risk of bias were RoB 2 and the NewcastleOttawa Scale (NOS).Seven articles met the inclusion criteria, with 4 classified as having a low risk of bias and 3 with a moderate risk of bias. The OD technique consistently demonstrated an average ISQ value of 73 KHz across all studies, whereas CD yielded an average value of 58.49 kHz (p < 0.001 for 5 articles).It can be concluded that in comparison with CD, OD improves primary stability at baseline in low-density bone, such as the maxilla.

Systemic Factors Affecting Prognosis of Dental Implants.

Clinicians who place and restore implants are always concerned about the success and longevity of the same. There are several local and systemic factors that affect osseointegration and the health of the peri-implant tissues. In this study, we review the systemic factors that can affect implant survival, osseointegration, and long-term success. The study highlights the importance of delineating, and taking into consideration these systemic factors from the planning phase to the restorative phase of dental implants. A thorough medical history, including prescription and over-the-counter medications, is vital, as there may be numerous factors that could directly or indirectly influence the prognosis of dental implants.

Osseointegration potential of boron-coated titanium alloy pedicle screw in rabbit spine model.

BACKGROUND: Spinal implants' longevity is crucial, but titanium alloys, while advantageous, lack strong bone integration. This study aimed to achieve better osseointegration rates by utilizing the ability of boron compounds to transform stem cells in the vertebra into osteoblasts. METHOD: Twenty male albino rabbits were divided into control (n = 10) and experimental (n = 10) groups. Control group received titanium alloy pedicle screws, while experimental group received boron-coated titanium alloy screws. Under general anesthesia, screws were inserted into the L6 and L7 lumbar spines. After 16 weeks, all animals were euthanized for histological examination. Vertebra samples underwent decalcification and H&E staining. Microscopic examination assessed osseointegration, necrosis, fibrosis, and vascularization using a triple scoring system by two blinded observers. RESULT: In the boron-coated titanium alloy group, all subjects exhibited osseointegration, with 50% showing focal, 40% moderate, and 10% complete osseointegration. In the titanium alloy group, 90% showed osseointegration (70% focal, 10% moderate, and 10% complete).The differences between the groups were not statistically significant (p = 0.302). Focal necrosis rates were similar between groups, with 50.0% in the titanium alloy and 60.0% in the boron-coated group (p = 0.653).Fibrosis was absent in the titanium alloy group but present in the boron-coated group, albeit with lower rates of focal fibrosis (20.0%). However, the difference was not statistically significant (p = 0.086).Vascularization patterns showed no significant difference between groups. CONCLUSION: Boron-coated titanium alloy pedicle screws provided osseointegration rates comparable to standard titanium screws and exhibited acceptable levels of necrosis and fibrosis. With stronger biomechanical properties, they could be a better alternative to currently used titanium screws.

Beyond the surface: exploring contributing factors to bone anchored hearing implant complications.

INTRODUCTION: Bone anchored hearing implants (BAHI) are considered for conductive and mixed hearing loss, relying on osseointegration of a titanium implant. Limitations relate to constant skin contact, with resultant percutaneous infections and granulation. This study investigates whether patient characteristics and implant-specifications contribute to BAHIs' skin complications in a cohort with a uniform surgical approach. METHODS: A 10 year (2014-2024) retrospective cohort study was conducted on BAHI procedures that were undertaken using a tissue-preserving 'punch' technique. Data on patient demographics, co-morbidities, implant type, surgical approach, and complications were collected. Poisson regression analysis was used to identify predictors of complications. RESULTS: A total of 53 patients undergoing 55 BAHI surgeries by three ENT consultants were included. Factors that greatly increased implant-related percutaneous infections included the Cochlear™ BIA400 implant when compared to the Ponto™ BHX implant (twofold, CI 2.03-2.16), abutment sizes ≤ 10 mm (fourfold, CI 3.99-4.12) and male gender (9%, CI 1.07-1.12). Granulation episodes were affected by cardiovascular disease (CVD) status (1.5-fold, CI 0.26-0.78), BIA400 implant (threefold, CI 8.8.-9.2) and abutment sizes ≤ 10 mm (fourfold, CI 3.6-3.73). Revision surgery episodes increased with diabetic status (1.2-fold, CI 0.06-0.37) and abutment sizes ≤ 10 mm (threefold, 3.303-3.304). CONCLUSIONS: Larger cohort studies are required to confirm findings, particularly for implant and abutment size contributions. However, the findings suggest that using a larger abutment size when skin thickness meassuremets are borderline, improved hygiene education in male patients, pre-operative optimisation of CVD and diabetes, and adjusted patient follow-up based on risk stratification of the contributing factors to complication rates could reduce complication rates.

Biomimetic HA-GO implant coating for enhanced osseointegration via macrophage M2 polarization-induced osteo-immunomodulation.

The pro-inflammatory/anti-inflammatory polarized phenotypes of macrophages (M1/M2) can be used to predict the success of implant integration. Hence, activating and inducing the transformation of immunocytes that promote tissue repair appears to be a highly promising strategy for facilitating osteo-anagenesis. In a previous study, titanium implants were coated with a graphene oxide-hydroxyapatite (GO-HA) nanocomposite via electrophoretic deposition, and the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) was found to be significantly enhanced when the GO content was 2wt%. However, the effectiveness of the GO-HA nanocomposite coating in modifying the in vivo immune microenvironment still remains unclear. In this study, the effects of GO-HA coatings on osteogenesis were investigated based on the GO-HA-mediated immune regulation of macrophages. The HA-2wt%GO nanocomposite coatings exhibited good biocompatibility and favored M2 macrophage polarization. Meanwhile, they could also significantly upregulate IL-10 (anti-inflammatory factor) expression and downregulate TNF-α (pro-inflammatory factor) expression. Additionally, the microenvironment, which was established by M2 macrophages, favored the osteogenesis of BMSCs both in vivo and in vitro. These findings show that the GO-HA nanocomposite coating is a promising surface-modification material. Hence, this study provides a reference for the development of next-generation osteoimmunomodulatory biomaterials.

Urolithin B inhibits the differentiation of M1 macrophages and relieves the inflammation around the implants under osteoporosis via down-regulating the phosphorylation of VEGFR2.

The inflammation causes the destroyed osseointegration at the implant-bone interface, significantly increasing the probability of implant loosening in osteoporotic patients. Currently, inhibiting the differentiation of M1 macrophages and the inflammatory response could be a solution to stabilize the microenvironment of implants. Interestingly, some natural products have anti-inflammatory and anti-polarization effects, which could be a promising candidate for stabilizing the implants' microenvironment in osteoporotic patients. This research aims to explore the inhibitory effect of Urolithin B(UB) on macrophage M1 polarization, which ameliorates inflammation, thus alleviating implant instability. We established an osteoporosis mouse model of implant loosening. The mouse tissues were taken out for morphological analysis, staining analysis, and bone metabolic index analysis. In in vitro experiments, RAW264.7 cells were polarized to M1 macrophages using lipopolysaccharide (LPS) and analyzed by immunofluorescence (IF) staining, Western blot (WB), and flow cytometry. The CSP100 plus chip experiments were used to explore the potential mechanisms behind the inhibiting effects of UB. Through observation of these experiments, UB can improve the osseointegration between the implants and femurs in osteoporotic mice and enhance the stability of implants. The UB can inhibit the differentiation of M1 macrophages and local inflammation via inhibiting the phosphorylation of VEGFR2, which can be further proved by the weakened inhibited effects of UB in macrophages with lentivirus-induced overexpression of VEGFR2. Overall, UB can specifically inhibit the activation of VEGFR2, alleviate local inflammation, and improve the stability of implants in osteoporotic mice.

Mechanochemically Reprogrammed Tantalum Interfaces Enhance Osseointegration Via Immunomodulation.

Bone and tooth defects can considerably affect the quality of life and health of patients, and orthopedic implants remain the primary method of addressing such defects. However, implant materials cannot coordinate with the immune microenvironment because of their biological inertness, which may lead to implant loosening or failure. Motivated by the microstructure of nacre, we engineered a biomimetic micro/nanoscale topography on a tantalum surface using a straightforward method. This comprised an organized array of tantalum nanotubes arranged in a brick wall structure, with epigallocatechin gallate acting as "mortar." The coating improved the corrosion resistance, biocompatibility, and antioxidant properties. In vitro and in vivo evaluations further confirmed that coatings can create a favorable bone immune microenvironment through the synergistic effects of mechanochemistry and enhance bone integration. This research offers a new viewpoint on the creation of sophisticated functional implants, possessing vast potential for use in the regeneration and repair of bone tissue.

Effects of dental implant surface biomodification with Limosilactobacillus reuteri on early bone healing: an experimental animal study.

The aim of this animal study was to compare the primary/secondary stability and micro-CT bone and tissue volumes of implants that were immersed in Limosilactobacillus reuteri, cholecalciferol-D3 (vitamin D) and injectable platelet-rich fibrin (i-PRF) suspensions/solutions before placement in bone. 40 implants (10 in each group) were placed in the iliac crest of 5 sheep. The implants were immersed in L. reuteri, vitamin D or i-PRF solutions for five minutes before placement or left unsoaked as controls. Implant stability was determined by ISQ values and bone volume around implants was histomorphometrically analysed by micro-CT evaluation. At 4 weeks, implants in the L. reuteri group showed the highest secondary stability and 2- and 3D BV/TV values. Both L. reuteri and vitamin D immersed implants had higher osseointegration values compared to the implants in the i-PRF group and controls. There were no statistical differences between L. reuteri and vitamin D immersed implants. Within the limits of the study, the results suggest that immersing implants in L. reuteri or vitamin D suspensions/solutions before implant placement in bone may have beneficial effects on osseointegration.

Near-Infrared Responsive Biomimetic Titanate/TiO2-X Heterostructure: A Therapeutic Strategy for Combating Implant-Associated Infection and Enhancing Osseointegration.

Implant-associated infections and delayed osseointegration are major challenges for the clinical success of titanium implants. To enhance antibacterial effects and promote early osseointegration, we developed a synergistic photothermal (PTT)/photodynamic (PDT) therapy strategy based on near-infrared (NIR) responsive biomimetic micro/nano titanate/TiO2-X heterostructure coatings (KMNW and NaMNS) in situ constructed on the surface of titanium implants. Specifically, KMNW and NaMNS significantly enhanced photothermal conversion capabilities, achieving localized high temperatures of 48-51 °C and promoting substantial amounts of reactive oxygen species production under 808 nm irradiation. In vitro antibacterial experiments demonstrated that KMNW achieved the highest antibacterial rates against Staphylococcus aureus and Escherichia coli, at 98.78 and 98.33% respectively. Moreover, by mimicking the three-dimensional fibrous network of the extracellular matrix during bone healing, both KMNW and NaMNS markedly promoted the proliferation and osteogenic differentiation of osteoblasts. In vivo implantation studies further confirmed these findings, with KMNW and NaMNS exhibiting superior antibacterial performance under NIR irradiation─94.45% for KMNW and 92.66% for NaMNS. Moreover, KMNW and NaMNS also significantly promoted new bone formation and improved osseointegration in vivo. This study presents a promising PTT/PDT therapeutic strategy for dentistry and orthopedics by employing NIR-responsive biomimetic coatings to combat implant-associated infection and accelerate osseointegration.

Advantages of customization of osseointegrated implants in transfemoral amputees: a comparative analysis of surgical planning.

BACKGROUND: Commercially available osseointegrated devices for transfemoral amputees are limited in size and thus fail to meet the significant anatomical variability in the femoral medullary canal. This study aimed to develop a customized osseointegrated stem to better accommodate a variety of femoral anatomies in transfemoral amputees than off-the-shelf stems. Customization is expected to enhance cortical bone preservation and increase the stem-bone contact area, which are critical for the long-term stability and success of implants. METHODS: A customized stem (OsteoCustom) was designed based on the statistical shape variability of the medullary canal. The implantability of the OsteoCustom stem was tested via 70 computed tomography (CT) images of human femurs and compared to that of a commercial device (OFI-C) for two different resection levels. The evaluations included the volume of cortical bone removed and the percentage of stem-bone contact area for both resection levels. Statistical significance was analyzed using paired and unpaired t tests. RESULTS: The OsteoCustom stem could be virtually implanted in all 70 femurs, while the OFI-C was unsuitable in 19 cases due to insufficient cortical thickness after implantation, further emphasizing its adaptability to varying anatomical conditions. The OsteoCustom stem preserved a greater volume of cortical bone than did the OFI-C. In fact, 42% less bone was removed at the proximal resection level (3.15 cm³ vs. 5.42 cm³, p ≤ 0.0001), and 33% less at the distal resection level (2.25 cm³ vs. 3.39 cm³, p = 0.003). The stem-bone contact area was also greater for the OsteoCustom stem, particularly at the distal resection level, showing a 20% increase in contact area (52.3% vs. 32.2%, p = 0.002) compared to that of the OFI-C. CONCLUSIONS: The OsteoCustom stem performed better than the commercial stem by preserving more cortical bone and achieving a greater stem-bone contact area, especially at distal resection levels where the shape of the medullary canal exhibits more inter-subject variability. Optimal fit in the distal region is of paramount importance for ensuring the stability of osseointegrated implants. This study highlights the potential benefits of customized osseointegrated stems in accommodating a broader range of femoral anatomies, with enhanced fit in the medullary canal.

Feasibility and Outcomes of an Active Osseointegrated Bone Conduction Implant in Children as Young as 5 Years of Age.

INTRODUCTION: This study reviews the feasibility of implanting active osseointegrated bone conduction devices in young children, below the prior age for FDA indication (<12 years), which has recently been reduced to 5 years. Outcomes included differences in adverse event rates and operative time between two groups (<12 and 12 years or older). MATERIALS AND METHODS: This study is a retrospective review of children receiving active osseointegrated bone conduction devices at a tertiary referral center academic hospital. One hundred and twenty-four children received 135 active osseointegrated bone conduction devices (May 2018-March 2024). RESULTS: Of 135 devices, 77 (57%) were in children <12 years (mean age (SD) = 7.9 (2.0) years, range = 4.9-11.9 years) and 58 (43%) were in 12 years or older (mean age (SD) = 15.1 (1.7) years, range = 12-18 years). Adverse events were significantly higher in the older group, occurring in 8 (10%) of 77 devices in children <12 years and 15 (26%) of 58 devices in children 12 years and older (26%) (Fisher's exact test = 0.0217 at p < 0.05). Major adverse events occurred in 5/124 (4%) patients, with 2 in patients <12 years (2/73, 3%) and 3 in children 12 and older (3/51, 6%). The proportion of major events between groups was not significantly different (Fisher's exact test = 0.4, p < 0.05). Mean surgical time was significantly less (t = -2.8799, df = 120.26, p = 0.005) in the children <12 years (mean (SD) = 66.5 (22.4) min) compared to those 12 and over (mean (SD) = 78.32 (23.1) min). CONCLUSIONS: Implantation of active osseointegrated bone conduction devices is feasible in children as young as 5 years and demonstrates low rates of complication. Further miniaturization may allow even earlier safe intervention.

Smart Delivery of Biomolecules Interfering with Peri-Implant Repair in Osteoporotic Rats.

Bisphosphonates are widely used for the treatment of postmenopausal osteoporosis; however, they cause several long-term side effects, necessitating the investigation of local ways to improve osseointegration in compromised bone tissue. The purpose of this study was to evaluate peri-implant bone repair using implants functionalized with zoledronic acid alone (OVX ZOL group, n = 11), zoledronic acid + teriparatide (OVX ZOL + TERI group, n = 11), and zoledronic acid + ruterpy (OVX ZOL + TERPY group, n = 11) compared to the control group (OVX CONV, n = 11). Analyses included computer-assisted microtomography, qualitative histologic analysis, and real-time PCR analysis. Histologically, all functionalized surfaces improved peri-implant repair, with the OVX ZOL + TERI group standing out. Similar results were found in computerized microtomography analysis. In real-time PCR analysis, however, the OVX ZOL and OVX ZOL + TERPY groups showed better results for bone formation, with the OVX ZOL + TERPY group standing out, while there were no statistical differences between the OVX CONV and OVX ZOL + TERI groups for the genes studied at 28 postoperative days. Nevertheless, all functionalized groups showed a reduced rate of bone resorption. In short, all surface functionalization groups outperformed the control group, with overall better results for the OVX ZOL + TERI group.