Implantable CAR T cell factories enhance solid tumor treatment

Chimeric Antigen Receptor (CAR) T cell therapy has produced revolutionary success in hematological cancers such as leukemia and lymphoma. Nonetheless, its translation to solid tumors faces challenges due to manufacturing complexities, short-lived in vivo persistence, and transient therapeutic impact. We introduce 'Drydux' - an innovative macroporous biomaterial scaffold designed for rapid, efficient in-situ generation of tumor-specific CAR T cells. Drydux expedites CAR T cell preparation with a mere three-day turnaround from patient blood collection, presenting a cost-effective, streamlined alternative to conventional methodologies. Notably, Drydux-enabled CAR T cells provide prolonged in vivo release, functionality, and enhanced persistence exceeding 150 days, with cells transitioning to memory phenotypes. Unlike conventional CAR T cell therapy, which offered only temporary tumor control, equivalent Drydux cell doses induced lasting tumor remission in various animal tumor models, including systemic lymphoma, peritoneal ovarian cancer, metastatic lung cancer, and orthotopic pancreatic cancer. Drydux's approach holds promise in revolutionizing solid tumor CAR T cell therapy by delivering durable, rapid, and cost-effective treatments and broadening patient accessibility to this groundbreaking therapy.

A Comparative Analysis of Implant-sparing Plan Versus Conventional Plans Utilizing Helical Tomotherapy in Breast Cancer Patients Undergoing Breast Reconstruction

BACKGROUND/AIM

To compare implant sparing irradiation with conventional radiotherapy (RT) using helical (H) and TomoDirect (TD) techniques in breast cancer patients undergoing immediate breast reconstruction (IBR).

PATIENTS AND METHODS

The dosimetric parameters of 40 patients with retropectoral implants receiving 50.4 Gy delivered in 28 fractions were analyzed. Three plans were created: H plan using conventional planning target volume (PTV) that included the chest wall, skin, and implant; TD plan using conventional PTV; and Hs plan using implant-sparing PTV. The H, TD, and Hs plans were compared for PTV doses, organ-at-risk (OAR) doses, and treatment times.

RESULTS

Dose distribution in the Hs plan was less homogeneous and uniform than that in the H and TD plans. The TD plan had lower lung, heart, contralateral breast, spinal cord, liver, and esophagus doses than the Hs plan. Compared to the Hs plan, the H plan had lower lung volume receiving 5Gy (V5) (39.1±3.9 vs. 41.2±3.9 Gy; p<0.001), higher V20 (12.3±1.3 vs. 11.5±2.6 Gy; p=0.02), and higher V30 (7.5±1.6 vs. 4.4±1.7 Gy; p<0.001). H plan outperformed Hs plan in heart dosimetric parameters except V20. The Hs plan had significantly lower mean implant doses (43.4±2.1 Gy) than the H plan (51.4±0.5 Gy; p<0.001) and the TD plan (51.9±0.6 Gy; p<0.001). Implementing an implant sparing technique for silicone dose reduction decreases lung doses.

CONCLUSION

Conventional H and TD plans outperform the implant sparing helical plan dosimetrically. Because capsular contracture during RT is unpredictable, long-term clinical outcomes are required to determine whether silicon should be spared.

In hospital outcomes of autologous and implant-based breast reconstruction in patients with chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a common comorbid condition that can be associated with postoperative mortality and morbidity. However, the outcome profile of patients with COPD after breast reconstruction has yet to be established. Therefore, this study aimed to assess the postoperative outcomes in patients with COPD who underwent autologous (ABR) and implant-based breast reconstruction (IBR).

METHODS

National Inpatient Sample was used to identify patients who underwent ABR or IBR from Q4 2015 to 2020. Multivariable logistic regressions were used to compare inhospital outcomes between COPD and non-COPD patients while adjusting for demographics, primary payer status, hospital characteristics, and comorbidities.

RESULTS

There were 1288 (9.92%) COPD and 11,696 non-COPD patients who underwent ABR. Meanwhile, 1742 (9.70%) COPD and 16,221 non-COPD patients underwent IBR. In both ABR and IBR, patients with COPD had higher rates of seroma (ABR, aOR = 1.863, 95% CI = 1.022-3.397, and p = 0.04; IBR, aOR = 1.524, 95% CI = 1.014-2.291, and p = 0.04), infection (ABR, aOR = 1.863, 95% CI = 1.022-3.397, and p = 0.04; IBR, aOR = 1.956, 95% CI = 1.205-3.176, and p = 0.01), and prolonged LOS (p < 0.01). Specifically, patients with COPD in ABR had higher risks of respiratory complications (aOR = 1.991, 95% CI = 1.291-3.071, and p < 0.01) and incurred higher total hospital charges (p < 0.01). Meanwhile, patients with COPD undergoing IBR had elevated risks of renal complications (aOR = 3.421, 95% CI = 2.108-5.55, and p < 0.01), deep wound complications (aOR = 3.191, 95% CI = 1.423-7.153, and p < 0.01), and a higher rate of transfers out (aOR = 1.815, 95% CI = 1.081-3.05, and p = 0.02).

CONCLUSION

COPD is an independent risk factor associated with distinct adverse outcomes in ABR and IBR. These findings can be valuable for preoperative risk stratification, determining surgical candidacy, and planning postoperative management in patients with COPD.

Soft Tissue Response and Determination of Underlying Risk Drivers for Recession and Mucositis after AMSJI Implantation in the Maxilla

PURPOSE

To evaluate the soft tissue response to the placement of additively manufactured subperiosteal jaw implants (AMSJI) in the severely atrophic maxilla and to identify possible risk factors for soft tissue breakdown.

MATERIALS AND METHODS

An international multicenter study was conducted, and 15 men (mean age: 64.62 years; SD: ± 6.75) and 25 women (mean age: 65.24 years; SD: ± 6.77) with advanced maxillary jaw resorption (Cawood and Howell Class V or more) were included in this study. General patient data were collected, and all subjects were clinically examined. Inclusion criteria were patients who underwent bilateral AMSJI placement in the maxilla at least 1 year prior. Exclusion criteria were patients who did not have patient, surgeon, or dentist consent to participate in the study before their inclusion.

RESULTS

A total of 40 patients were enrolled, with a mean follow-up period of 917 days (SD: ± 306.89 days). Primary implant stability was achieved postoperatively in all cases, and all implants were loaded with a final prosthesis. At the time of the study, only 1 patient showed mobility (> 1 mm) of the bilateral AMSJI. Due to mucosal recession, exposure of the framework was seen in 26 patients (65%) and was mainly in the left (21.43% of 26) and right (18.57% of 26) midlateral region. A thin biotype and the presence of mucositis were found to be risk factors (P < .05). Although not significant, smokers had a risk of developing a recession that was nearly seven times (odds ratio: 6.88; P = .08) greater than that of nonsmokers.

CONCLUSIONS

Twenty-six (65%) patients presented with a recession in one (or more) of the seven regions after oral rehabilitation with bilateral AMSJI placement. Several risk drivers were evaluated. The collapse of soft tissues around the AMSJI that led to caudal exposure of the arms was correlated with a thin biotype and the presence of mucositis.

Kinematic performance of a novel temporomandibular joint replacement prosthesis under bite-force conditions in dogs and cats

OBJECTIVE

To evaluate the kinematics and stability of the temporomandibular joint (TMJ) of cats and dogs with and without a TMJ replacement (TMJR) prosthesis under simulated bite forces and mouth opening.

ANIMALS

Sixteen cadaver skulls from domestic cats (n = 8) and medium- to large-breed dogs (n = 8).

METHODS

Intact TMJs were tested. Following condylectomy and coronoidectomy, the skulls were fitted with a TMJR prosthesis unilaterally and retested. Prosthesis was similarly implanted in the contralateral TMJ in 4 cats and 4 dogs before retesting. Left and right bite motions were evaluated before bite contact to peak bite force (200 N in dogs, 63 N in cats). Mouth opening motion was recorded. Mandibular displacement under load was evaluated in 3 orthogonal planes. Maximal displacement was compared between TMJR groups and native TMJ. Prosthesis-bone motion of the temporal and mandibular components was evaluated during simulated bites and mouth opening.

RESULTS

TMJR resulted in joint motion not demonstrably different from the native TMJ, with the ability to fully open and close the mouth and with minimal laterotrusion. The TMJR prosthesis demonstrated similar stability after unilateral and bilateral replacement during bite force and with an open mouth. Mean implant-bone motion during bite simulations for the temporal and mandibular TMJR components was ≤ 60 µm in cats and ≤ 30 µm in dogs.

CLINICAL RELEVANCE

A novel TMJR can be implanted and allows normal jaw motion. Joint stability is maintained after TMJR implantation in the TMJ of dogs and cats TMJ that is devoid of muscular support.

Multifunctional Hybrid Material for Endoprosthetic Implants Based on Alumina-Toughened Zirconia Ceramics and Additively Manufactured TiNbTa Alloys

Aseptic implant loosening after a total joint replacement is partially influenced by material-specific factors when cobalt-chromium alloys are used, including osteolysis induced by wear and corrosion products and stress shielding. Here, we aim to characterize a hybrid material consisting of alumina-toughened zirconia (ATZ) ceramics and additively manufactured Ti-35Nb-6Ta (TiNbTa) alloys, which are joined by a glass solder. The structure of the joint, the static and fatigue shear strength, the influence of accelerated aging, and the cytotoxicity with human osteoblasts are characterized. Furthermore, the biomechanical properties of the functional demonstrators of a femoral component for total knee replacements are evaluated. The TiNbTa-ATZ specimens showed a homogenous joint with statistically distributed micro-pores and a slight accumulation of Al-rich compounds at the glass solder-TiNbTa interface. Shear strengths of 26.4 ± 4.2 MPa and 38.2 ± 14.4 MPa were achieved for the TiNbTa-ATZ and Ti-ATZ specimens, respectively, and they were not significantly affected by the titanium material used, nor by accelerated aging (p = 0.07). All of the specimens survived 107 cycles of shear loading to 10 MPa. Furthermore, the TiNbTa-ATZ did not impair the proliferation and metabolic activity of the human osteoblasts. Functional demonstrators made of TiNbTa-ATZ provided a maximum bearable extension-flexion moment of 40.7 ± 2.2 Nm. The biomechanical and biological properties of TiNbTa-ATZ demonstrate potential applications for endoprosthetic implants.

16S rRNA sequencing reveals microbiota differences in orthopedic implants between aseptic loosening and prosthetic joint infection cases

Prosthetic joint infection (PJI) and aseptic loosening (AL) are common complications of total joint arthroplasty. An accumulation of evidence indicates the presence of microbial communities on prosthetic implants, but the overall microbial profile is unclear. In this study, we aimed to investigate the differences in the microbial composition of prosthetic implants obtained from PJI and AL patients using the 16S rRNA sequencing method. Patients who underwent revision hip, knee, or shoulder arthroplasty caused by PJI (n = 20) or AL (n = 10) were enrolled in the study. 16S rRNA sequencing targeting the V3-V4 region was performed on the microbial specimens collected from synovial fluid, periprosthetic deep-tissue, and biofilm during the revision surgery. The sequenced raw data were analysed for microbial composition and ecological and differential abundance analyses using bioinformatics tools. The AL group had relatively balanced and higher diversity, with Staphylococcus, Streptococcus, and Veillonella being prominent. In the PJI group, Staphylococcus and Pseudomonas were predominant, especially in deep-tissue samples and biofilm samples, respectively. The differential abundance analysis identified 15 and 2 distinctive taxa in the AL and PJI groups, respectively. Our findings provided preliminary insights supporting the existence of periprosthetic microbiota in orthopedic implants and explaining the differences in microbial composition between the AL and PJI groups.

Transcatheter Pulmonary Valve Replacement With the Harmony Valve in Patients Who Do Not Meet Recommended Oversizing Criteria on the Screening Perimeter Plot

BACKGROUND

Anatomic selection for Harmony valve implant is determined with the aid of a screening report and perimeter plot (PP) that depicts the perimeter-derived radius along the right ventricular outflow tract (RVOT) and projects device oversizing. The PP provides an estimation of suitability for implant, but its sensitivity as a screening method is unknown. This study was performed to describe anatomic features and outcomes in patients who underwent Harmony TPV25 implant despite a PP that predicted inadequate oversizing.

METHODS

We reviewed RVOT anatomic features and measurements in patients who underwent transcatheter pulmonary valve replacement with the Harmony TPV25 device despite a PP that predicted inadequate oversizing.

RESULTS

This study included 22 patients. There were no unsuccessful implants or adverse valve-related events. Anatomic features varied, but all patients fit into 1 of 3 anatomic types characterized by differences in RVOT dimensions. Type 1 patients (n=9) had a long RVOT with a choke point and a wide main pulmonary artery. Type 2 patients (n=6) had a short RVOT that was pyramidal in shape, with no choke point, and extensive main pulmonary artery lengthening/expansion during systole. Type 3 patients (n=7) had a short, bulbous main pulmonary artery with a choke point and an open pulmonary artery bifurcation.

CONCLUSIONS

Transcatheter pulmonary valve replacement with the Harmony valve is feasible in some patients whose PP fit analysis predicts inadequate oversizing. All cases in this series fit into 1 of 3 anatomic patterns, which are not identified in the screening report. Implanters must review cases individually to assess the feasibility of the implant.

The role of kyphoplasty and expandable intravertebral implants in the acute treatment of traumatic thoracolumbar vertebral compression fractures: a systematic review

Purpose

The aim of the study was to assess the role of kyphoplasty and expandable intravertebral implants in the treatment of traumatic vertebral compression fractures.

Design

This is a systematic review.

Methods

A bibliographic search was carried out in the PubMed/MEDLINE database according to PRISMA guidelines regarding kyphoplasty and expandable intravertebral implants in the treatment of traumatic thoracolumbar vertebral fractures.

Results

A total of 611 records were screened. In total, 51 studies were obtained referring to traumatic vertebral fractures treated with kyphoplasty; however, of these, only studies addressing traumatic burst fractures were selected, resulting in 12 studies: 10 about kyphoplasty and 2 regarding armed kyphoplasty. In all studies, there was a statistically significant improvement in clinical and functional parameters, restoration of vertebral height and decreasing of vertebral and segmental kyphosis. Overall, there was only a residual loss of height and a slight increase in kyphosis throughout the follow-up period, while complications consisted essentially of cement leakage, all with no clinical repercussions.

Conclusion

After the discussion, where we address the concepts of direct and indirect reduction, the association of kyphoplasty with pedicle fixation, the potential advantages of expandable intravertebral implants, as well as the vertebral body type of filling in kyphoplasty, it is concluded that kyphoplasty demonstrates favorable outcomes as a method of posterior percutaneous transpedicular access for reconstruction of the anterior column in burst fractures. It allows for the reconstruction of the vertebral body closer to its original anatomy, carried out in a minimally invasive and safe way, which provides a clinical-functional and imaging improvement maintained at the medium-long term.

In hospital outcomes of autologous and implant-based breast reconstruction in patients with diabetes mellitus: A population-based study of 2015-2020 national inpatient sample

BACKGROUND

Breast reconstruction encompasses autologous (ABR) and implant-based breast reconstruction (IBR) each with its own sets of potential complications. Diabetes mellitus (DM) is associated with breast reconstruction complications, although most of the studies did not differentiate between the reconstruction procedures. This study conducted a population-based study examining impact of DM on inhospital outcomes in ABR and IBR.

METHODS

Patients underwent ABR or IBR were identified in National Inpatient Sample from Q4 2015 to 2020. A 1:2 propensity score matching was used to address differences in demographics, hospital characteristics, primary payer status, comorbidities, and reconstruction staging between DM and non-DM patients. In hospital outcomes were assessed separately in ABR and IBR.

RESULTS

There were 997 (7.68%) DM and 11,987 (92.32%) non-DM patients in ABR. Meanwhile, 1325 (7.38%) DM and 16,638 (92.62%) non-DM patients underwent IBR. DM cohorts in ABR and IBR were matched to 1930 and 2558 non-DM patients, respectively. After matching, DM patients in both ABR and IBR had higher risks of renal complications (ABR, 3.73% vs. 1.76%, p < 0.01; IBR, 1.83% vs. 0.78%, p = 0.01) and longer length of stay (ABR, p = 0.01; IBR, p = 0.04). In ABR, DM patients had higher respiratory complications (2.82% vs. 1.19%, p < 0.01), excessive scarring (2.72% vs. 1.55%, p = 0.03), and infection (2.42% vs. 1.14%, p = 0.01), while in IBR, DM patients had higher hemorrhage/hematoma (5.40% vs. 3.40%, p < 0.01) and transfer out (1.52% vs. 0.78%, p = 0.04).

CONCLUSION

DM was associated with distinct sets of inhospital complications in ABR and IBR, which can be valuable for preoperative risk stratification and informing clinical decision-making for DM patients.

Effect of guided implant placement learning experiences on freehand skills: A pilot study

OBJECTIVES

Guided implant systems can be used as a training approach for placing implants. This in vitro prospective randomized pilot study evaluated the learning progression and skill development in freehand placement of two implants supporting a three-unit fixed prosthesis on a simulation model among novice operators.

MATERIAL AND METHODS

Four senior dental students with no prior implant placement experience participated in the study. As a baseline, each student placed two mandibular and two maxillary implants by freehand technique on a simulation model. Sixteen consecutive guided placements using a static guide, dynamic navigation, and template-based guide followed totaling 32 guided implant placements into maxillary and mandibular models. Freehand implant placements before and after the various guided navigation attempts were compared to assess their impact on freehand skill. Metrics compared included surgical time, horizontal, vertical, and angulation discrepancies between the planned and placed implant positions measured on superimposed CBCT scans and analyzed with repeated measures regression with Tukey's adjusted pairwise comparisons (α = .05).

RESULTS

Before training with guided techniques, the average baseline freehand implant placement took 10.2 min and decreased to 8.2 after training but this difference was not statistically significant (p = .1670) There was marginal evidence of a significant difference in the 3D apex deviation with an average improvement of 0.89 mm (95% CI: -0.38, 2.16, p = .1120); and marginal evidence of a significant improvement in the overall angle with an average improvement of 3.74° (95% CI: -1.00, 8.48, p = .0869) between baseline and final freehand placement attempts.

CONCLUSIONS

Within the limitations of this pilot study, guided implant placement experiences did not significantly benefit or hinder freehand placement skills. Dental students should be exposed to various placement techniques to prepare them for clinical practice and allow them to make informed decisions on the best technique based on their skills and a given clinical scenario.

Enhanced osteogenic and antibacterial properties of titanium implant surface modified with Zn-incorporated nanowires: Preclinical in vitro and in vivo investigations

OBJECTIVE

This study aimed to synthesize zinc-incorporated nanowires structure modified titanium implant surface (Zn-NW-Ti) and explore its superior osteogenic and antibacterial properties in vitro and in vivo.

MATERIALS AND METHODS

Zn-NW-Ti was synthesized via displacement reactions between zinc sulfate solutions and the titanium (Ti) surface, which was pretreated by hydrofluoric acid etching and hyperthermal alkalinization. The physicochemical properties of the Zn-NW-Ti surface were examined. Moreover, the biological effects of Zn-NW-Ti on MC3T3-E1 cells and its antibacterial property against oral pathogenic bacteria (Staphylococcus aureus, Porphyromonas gingivalis, and Actinobacillus actinomycetemcomitans) compared with sandblasted and acid-etched Ti (SLA-Ti) and nanowires modified Ti (NW-Ti) surface were assessed. Zn-NW-Ti and SLA-Ti modified implants were inserted into the anterior extraction socket of the rabbit mandible with or without exposure to the mixed bacterial solution (S. aureus, P. gingivalis, and A. actinomycetemcomitans) to investigate the osteointegration and antibacterial performance via radiographic and histomorphometric analysis.

RESULTS

The Zn-NW-Ti surface was successfully prepared. The resultant titanium surface appeared as a nanowires structure with hydrophilicity, from which zinc ions were released in an effective concentration range. The Zn-NW-Ti surface performed better in facilitating the adhesion, proliferation, and differentiation of MC3T3-E1 cells while inhibiting the colonization of bacteria compared with SLA-Ti and NW-Ti surface. The Zn-NW-Ti implant exhibited enhanced osseointegration in vivo, which was attributed to increased osteogenic activity and reduced bacterial-induced inflammation compared with the SLA-Ti implant.

CONCLUSIONS

The Zn-incorporated nanowires structure modified titanium implant surface exhibited improvements in osteogenic and antibacterial properties, which optimized osteointegration in comparison with SLA titanium implant surface.

Microbiological profile of peri-implantitis: Analyses of peri-implant microbiome

PURPOSE

To characterize the microbiome composition in peri-implant pocket of peri-implantitis and peri-implant sulcus controls using 16S rRNA gene sequencing.

MATERIALS AND METHODS

In this controlled clinical cross-sectional study, 23 subjects with control implants (n = 14) and diseased implants (peri-implantitis, n = 21) were included. The peri-implant pocket/sulcus was sampled and used to extract DNA and amplify the 16S rRNA gene using universal primers targeting the V3-V4 regions. The resulting 16S PCR amplicons were sequenced on Illumina MiSeq, and the sequences were processed using DADA2 and the Human Oral Microbiome Database (HOMD) as references. Alpha and Beta diversity, as well as core microbiome and differential abundance analyses, were performed using the MicrobiomeAnalyst workflow.

RESULTS

There were no significant differences in microbial diversity between control implants and implants with peri-implantitis (Shannon p = 0.82). Overall bacterial community structure assessed through beta diversity analysis was also not significantly different between the two groups (p = 0.18). However, high levels of Gram-negative bacteria were detected in peri-implant pockets compared to the control sulcus. Abundant species in peri-implantitis were Capnocytophaga leadbetteri, Treponema maltophilum, Peptostreptococcus, Neisseria, P. gingivalis, and Porphyromonas endodontali, Lactococcus lactis and Filifactor alocis (p < 0.05). Gram-positive bacteria such as Streptococcus salivaris, Prevotella melaninogenica, L. wadei, and Actinomyces spp. serve were more abundant in peri-implant control sulcus.

CONCLUSIONS

Peri-implant sulcus in control implants harbors predominantly Gram-positive bacteria, whereas pockets of implants with peri-implantitis harbor predominantly Gram-negative bacteria.

Poly(Glutamic Acid-Lysine) Hydrogels with Alternating Sequence Resist the Foreign Body Response in Rodents and Non-Human Primates

The foreign body response (FBR) to implanted biomaterials and biomedical devices can severely impede their functionality and even lead to failure. The discovery of effective anti-FBR materials remains a formidable challenge. Inspire by the enrichment of glutamic acid (E) and lysine (K) residues on human protein surfaces, a class of zwitterionic polypeptide (ZIP) hydrogels with alternating E and K sequences to mitigate the FBR is prepared. When subcutaneously implanted, the ZIP hydrogels caused minimal inflammation after 2 weeks and no obvious collagen capsulation after 6 months in mice. Importantly, these hydrogels effectively resisted the FBR in non-human primate models for at least 2 months. In addition, the enzymatic degradability of the gel can be controlled by adjusting the crosslinking degree or the optical isomerism of amino acid monomers. The long-term FBR resistance and controlled degradability of ZIP hydrogels open up new possibilities for a broad range of biomedical applications.

Flapless dental implant surgery enabled by haptic robotic guidance: A case report

This case report presents the use of haptic robotic technology in one patient with six implants placed in the maxilla and five implants in the lower mandible with the goal of individual single implant supported crowns to be placed over each implant after 6 months. All implants were placed using a flapless technique, with one immediate implant placement after extraction. All implants were placed with a high degree of accuracy relative to the pre-operative plan as determined by post-op CBCT analysis with an average angular deviation of 2.58° and positional deviations at the coronal and apical aspects of the implant around 1 mm (0.93 and 1.06 mm, respectively). Total surgical time of less than 2 h. Haptic robotics physically guides the location, orientation, and depth of the tools during both drilling and implantation and thus allows for accurate placement as well as the intra-operative flexibility to change the plan as necessary while providing excellent visualization and irrigation. This robotic technology provides a treatment that focuses on accuracy and safety providing the best chance at excellent surgical outcomes for the patient.

Effect of implant type on the stability of cantilever fixed dental prostheses: An in vitro study

OBJECTIVES

To simulate the replacement of a premolar with an implant-supported cantilever fixed dental prosthesis (ICFDP) and how the fracture load is affected by implant type, positioning within the zirconia blank, and aging protocol.

MATERIALS AND METHODS

Seventy-two ICFDPs were designed either within the enamel- or dentin layer of a 4Y-PSZ blank for bone-level and tissue-level titanium-zirconium implants. Fracture load was obtained on the cantilever at baseline (no aging) or after aging in a chewing simulator with the load applied within the implant axis (axial aging) or on the cantilever (12 groups with n = 6). A three-way ANOVA was applied (α = .05).

RESULTS

A three-way ANOVA revealed a significant effect on fracture load values of implant type (p = .006) and aging (p < .001) but not for the position within the zirconia blank (p = .847). Fracture load values significantly increased from baseline bone level (608 ± 118 N) and tissue level (880 ± 293 N) when the implants were aged axially, with higher values for tissue level (1065 ± 182 N) than bone level (797 ± 113 N) (p < .001). However, when the force was applied to the cantilever, fracture load values decreased significantly for tissue-level (493 ± 70 N), while values for bone-level implants remained stable (690 ± 135 N).

CONCLUSIONS

For ICFDPs, the use of bone-level implants is reasonable as catastrophic failures are likely to be restricted to the restoration, whereas with tissue-level implants, the transmucosal portion of the implant is susceptible to deformation, making repair more difficult.

Stress distribution on implant- supported zirconia crown of maxillary first molar: effect of oblique load on natural and antagonist tooth

This study evaluated the stress distribution on an implant-supported zirconia crown of a mandibular first molar subjected to oblique loading by occlusal contact with the natural maxillary first molar by using the 3D finite element method. Two virtual models were made to simulate the following situations: (1) occlusion between maxillary and mandibular natural first molars; (2) occlusion between zirconia implant-supported ceramic crown on a mandibular first molar and maxillary natural first molar. The models were designed virtually in a modeling program or CAD (Computer Aided Design) (Rhinoceros). An oblique load of 100 N was uniformly applied to the zirconia framework of the crown. The results were obtained by the Von Mises criterion of stress distribution. Replacement of the mandibular tooth by an implant caused a slight increase in stress on portions of the maxillary tooth roots. The crown of the maxillary model in occlusion with natural antagonist tooth showed 12% less stress when compared with the maxillary (model in occlusion with the) implant-supported crown. The mandibular crown of the implant show 35% more stress when compared with the mandibular antagonist crown on the natural tooth. The presence of the implant to replace the mandibular tooth increased the stresses on the maxillary tooth, especially in the region of the mesial and distal buccal roots.

Wireless Stimulation of Motor Cortex Through a Collagen Dura Substitute Using an Ultra-Thin Implant Fabricated on Parylene/PDMS

We present the design, fabrication, and in vivo testing of an ultra-thin (100 μm) wireless and battery-free implant for stimulation of the brain's cortex. The implant is fabricated on a flexible and transparent parylene/PDMS substrate, and it is miniaturized to dimensions of 15.6 × 6.6 mm 2. The frequency and pulse width of the monophasic voltage pulses are determined through On-Off keying (OOK) modulation of a wireless transmission at 2.45 GHz. Furthermore, the implant triggered a motor response in vivo when tested in 6 rodents. Limb response was observed by wireless stimulation of the brain's motor cortex through an FDA-approved collagen dura substitute that was placed on the dura in the craniotomy site, with no direct contact between the implant's electrodes and the brain's cortical surface. Therefore, the wireless stimulation method reported herein enables the concept of an e-dura substitute, where wireless electronics can be integrated onto a conventional dura substitute to augment its therapeutic function and administer any desired stimulation protocol without the need for post-surgical intervention for battery replacement or reprogramming stimulation parameters.

Efficacy of etonogestrel subcutaneous implants versus the levonorgestrel-releasing intrauterine system in the conservative treatment of adenomyosis

To evaluate the clinical efficacy of etonogestrel subcutaneous implant (ENG-SCI) with that of the levonorgestrel-releasing intrauterine system (LNG-IUD) for adenomyosis treatment. A prospective randomized cohort study was conducted including 108 patients (50 patients in ENG-SCI group and 58 in the LNG-IUD group) with adenomyosis from January 2019 to July 2021. After 3 months of treatment, both ENG-SCI group and LNG-IUD group showed significant improvement in patients' visual analog scale, pictorial blood loss assessment chart (PBAC), and uterine volume (P ＜ 0.05). The uterine volume of patients in LNG-IUD group decreased more significantly than that in the ENG-SCI group since 3 months of treatment. The PBAC score in the LNG-IUD group improved better than that in the ENG-SCI group since 6 months of treatment (P ＜ 0.05). No significant difference in the occurrence rate of ideal vaginal bleeding patterns and the hemoglobin levels between the two groups was observed. The ENG-SCI group had a higher probability of weight gain and progesterone-related side effects (P ＜ 0.05). Both ENG-SCI and LNG-IUD were effective in treatment of adenomyosis. However, LNG-IUD had a more significant effect in treating adenomyosis-related dysmenorrhea, excessive menstrual flow, anemia, and uterine enlargement, with relatively fewer side effects.

In vitro and in vivo evaluation of the osseointegration capacity of a polycarbonate-urethane zirconium-oxide composite material for application in a focal knee resurfacing implant

Currently available focal knee resurfacing implants (FKRIs) are fully or partially composed of metals, which show a large disparity in elastic modulus relative to bone and cartilage tissue. Although titanium is known for its excellent osseointegration, the application in FKRIs can lead to potential stress-shielding and metal implants can cause degeneration of the opposing articulating cartilage due to the high resulting contact stresses. Furthermore, metal implants do not allow for follow-up using magnetic resonance imaging (MRI).To overcome the drawbacks of using metal based FKRIs, a biomimetic and MRI compatible bi-layered non-resorbable thermoplastic polycarbonate-urethane (PCU)-based FKRI was developed. The objective of this preclinical study was to evaluate the mechanical properties, biocompatibility and osteoconduction of a novel Bionate® 75D - zirconium oxide (B75D-ZrO2 ) composite material in vitro and the osseointegration of a B75D-ZrO2 composite stem PCU implant in a caprine animal model. The tensile strength and elastic modulus of the B75D-ZrO2 composite were characterized through in vitro mechanical tests under ambient and physiological conditions. In vitro biocompatibility and osteoconductivity were evaluated by exposing human mesenchymal stem cells to the B75D-ZrO2 composite and culturing the cells under osteogenic conditions. Cell activity and mineralization were assessed and compared to Bionate® 75D (B75D) and titanium disks. The in vivo osseointegration of implants containing a B75D-ZrO2 stem was compared to implants with a B75D stem and titanium stem in a caprine large animal model. After a follow-up of 6 months, bone histomorphometry was performed to assess the bone-to-implant contact area (BIC). Mechanical testing showed that the B75D-ZrO2 composite material possesses an elastic modulus in the range of the elastic modulus reported for trabecular bone. The B75D-ZrO2 composite material facilitated cell mediated mineralization to a comparable extent as titanium. A significantly higher bone-to-implant contact (BIC) score was observed in the B75D-ZrO2 implants compared to the B75D implants. The BIC of B75D-ZrO2 implants was not significantly different compared to titanium implants. A biocompatible B75D-ZrO2 composite approximating the elastic modulus of trabecular bone was developed by compounding B75D with zirconium oxide. In vivo evaluation showed an significant increase of osseointegration for B75D-ZrO2 composite stem implants compared to B75D polymer stem PCU implants. The osseointegration of B75D-ZrO2 composite stem PCU implants was not significantly different in comparison to analogous titanium stem metal implants.

Radiopacity Enhancements in Polymeric Implant Biomaterials: A Comprehensive Literature Review

Polymers as biomaterials possess favorable properties, which include corrosion resistance, light weight, biocompatibility, ease of processing, low cost, and an ability to be easily tailored to meet specific applications. However, their inherent low X-ray attenuation, resulting from the low atomic numbers of their constituent elements, i.e., hydrogen (1), carbon (6), nitrogen (7), and oxygen (8), makes them difficult to visualize radiographically. Imparting radiopacity to radiolucent polymeric implants is necessary to enable noninvasive evaluation of implantable medical devices using conventional imaging methods. Numerous studies have undertaken this by blending various polymers with contrast agents consisting of heavy elements. The selection of an appropriate contrast agent is important, primarily to ensure that it does not cause detrimental effects to the relevant mechanical and physical properties of the polymer depending upon the intended application. Furthermore, its biocompatibility with adjacent tissues and its excretion from the body require thorough evaluation. We aimed to summarize the current knowledge on contrast agents incorporated into synthetic polymers in the context of implantable medical devices. While a single review was found that discussed radiopacity in polymeric biomaterials, the publication is outdated and does not address contemporary polymers employed in implant applications. Our review provides an up-to-date overview of contrast agents incorporated into synthetic medical polymers, encompassing both temporary and permanent implants. We expect that our results will significantly inform and guide the strategic selection of contrast agents, considering the specific requirements of implantable polymeric medical devices.

Risk factors for severe complications and salvage management in direct-to-implant immediate breast reconstruction: A retrospective study

Controversies regarding the risk factors affecting direct-to-implant (DTI) immediate breast reconstruction still exist. This study aimed to evaluate the risk factors for severe complications in DTI breast reconstruction and explore potential salvage management strategies. We conducted a retrospective review of 238 patients (240 breasts) who underwent DTI immediate breast reconstruction between 2011 and 2020. Multivariate logistic regression analyses were used to identify the risk factors predicting severe complications. Seventeen (7.08%) reconstructed breasts experienced severe complications, of which only 5 were successfully salvaged through surgical revision, while the others failed and resulted in implant removal. Multivariate analyses demonstrated that mesh use [odds ratio (OR) = 4.054, 95% confidence interval: 1.376-11.945, P = .011] and post-mastectomy radiotherapy (odds ratio = 4.383, 95% confidence interval 1.142-16.819, P = .031) were independent predictors of severe complications. Mesh use and post-mastectomy radiotherapy for breast reconstruction increase the risk of severe complications. Despite positive surgical treatment, the successful salvage rate was poor.

The contribution of metal allergy to the failure of metal alloy implants, with special reference to titanium: Current knowledge and controversies

After almost three-quarters of a century during which contact dermatologists have often struggled to comprehend the relationship between metal allergy and failure of metal-alloy containing implant, it is possible to say that a relationship does exist, particularly for cobalt and chromium, but also for nickel. There is still debate as to whether allergy develops as a consequent of failure but thenceforth contributes to it, or whether sensitisation starts first and induces failure secondarily-opinion probably favours the first. Metal-on-polypropylene articulations were associated with few metal allergic problems but now are less favoured by orthopaedists due to plastic wear products causing osteolysis and pseudotumour formation through local inflammation. New metal alloys are regularly being introduced such that interested dermatologists need to stay on top of the situation. The jury is still out as to whether the recent favouring of titanium-containing alloys will confirm them to be more inert allergenically. Case reports do show some clinical reactions to titanium-containing implants and patch test series have inferred sometimes quite a high background rate of allergy, but interpretation must be tempered by the awareness that titanium salts on patch testing have a tendency to cause irritant reactions. Blood monitoring of metal ion values is now recommended in certain situations after joint replacement and increasing levels may be an indication that allergy with joint failure can develop, in which case patch testing is indicated, and suggested series are available. Predictive patch testing, whilst generally not recommended in the past, has been introduced into some protocols often by non-dermatologists, such that it is now needed for temporo-mandibular joint and Nuss bar insertion, and it can be anticipated that this may become more commonplace in the future. One of the major current deficits for patch testers is standardised guidance on which preparation or preparations to use for suspected titanium allergy. One suggestion is 0.5% titanium sulphate in petrolatum, though experience in at least one centre suggests the use of a battery of titanium salts might be desirable.

Impact of surface characteristics on the peri-implant microbiome in health and disease

BACKGROUND

Because little is known about the impact of implant surface modifications on the peri-implant microbiome, we aimed to examine peri-implant communities in various surface types in order to better understand the impact of these surfaces on the development of peri-implantitis (PI).

METHODS

One hundred and six systemically healthy individuals with anodized (AN), hydroxyapatite-coated (HA), or sandblasted acid-etched (SLA) implants that were >6 months in function were recruited and categorized into health (H) or PI. Peri-implant biofilm was analyzed using 16S rRNA gene sequencing and compared between health/disease and HA/SLA/AN using community-level and taxa-level metrics.

RESULTS

Healthy implants did not demonstrate significant differences in clustering, alpha- or beta-diversity based on surface modification. AN and HA surfaces displayed significant differences between health and PI (p < 0.05); however, such a clustering was not evident with SLA (p > 0.05). AN and HA surfaces also differed in the magnitude and diversity of differences between health and PI. Six species belonging to the genera Shuttleworthia, Scardovia, and Prevotella demonstrated lower abundances in AN implants with PI, and 18 species belonging to the genera Fretibacterium, Tannerella, Treponema, and Fusobacterium were elevated, while in HA implants with PI, 20 species belonging to the genera Streptococcus, Lactobacillus, Veillonella, Rothia, and family Ruminococcaceae were depleted and Peptostreptococcaceae, Atopobiaceae, Veillonellaceae, Porphyromonadaceae, Desulfobulbaceae, and order Synergistales were enriched.

CONCLUSIONS

Within the limitations of this study, we demonstrate that implant surface can differentially modify the disease-associated microbiome, suggesting that surface topography must be considered in the multi-factorial etiology of peri-implant diseases.

The Effect of Frontal Deformity at the Ankle Joint on Total Ankle Arthroplasty Revision Rate

The presence of severe coronal plane deformity in the ankle joint is widely recognized as challenging to correct by total ankle joint arthroplasty alone, necessitating additional rearfoot fusion. The primary aim of this retrospective study was to investigate the potential associations between the presence or severity of coronal tibiotalar deformities and adverse outcomes after isolated total ankle arthroplasty, such as revisions and complications. The secondary aim was to analyze the potential associations between comorbidities, demographics, and implant types, and adverse outcomes. Our study's distinctive feature was its exclusive concentration on patients with deformities centralized in the ankle joint. Chart review was performed on 496 ankles in 456 patients who had a total ankle arthroplasty by 5 surgeons from 1/1/2010 to 12/31/2019. After exclusion and inclusion criteria were applied, total of 214 ankles in 210 patients were included for data analysis. At a mean follow-up period of 3 ± 2.0 years, our cohort had 15 (7.0%) revisions and 15 (7.0%) complications. Multivariable logistic regression model showed that the presence or severity of the coronal deformity was not significantly associated with incidences of revisions or complications. Female patients had significantly lower revision rate. Otherwise, the differences in age, race, body mass index, tobacco use, presence of diabetes, chronic kidney disease, atrial fibrillation, length of surgery, or type of implant were not significantly associated with incidences of revisions or complications. Further study could be performed to analyze the extent and duration that the coronal deformity correction is maintained after total ankle arthroplasty as well as the effect of each soft tissue procedure performed with the total ankle arthroplasty.

Ridge Preservation and Augmentation Using a Carbonated Apatite Bone Graft Substitute: A Case Series

The newly developed mineral carbonated apatite has recently been proposed as a bone graft material for bone regenerative treatment in implant therapy. This case series details the clinical and radiographic outcomes of ridge preservation and ridge augmentation using only carbonated apatite as bone graft material for implant treatment. Twenty patients (36 sites) who required bone regeneration and implant placement were retrospectively assessed. Simultaneous carbonated apatite implant placement was performed using the simultaneous ridge preservation or augmentation approach on 24 sites in 13 patients with sufficient bone quantity for primary stabilization based on preoperative evaluation results. A staged ridge preservation or augmentation approach was used for the remaining 12 sites in seven patients with insufficient bone quantity. The mean regenerated bone height for each treatment method was as follows: simultaneous preservation, 7.4 ± 3.3 mm; simultaneous augmentation, 3.6 ± 2.3 mm; staged preservation, 7.2 ± 4.5 mm; and staged augmentation, 6.1 ± 2.7 mm. The mean regenerated bone width for each treatment method was as follows: simultaneous preservation, 6.5 ± 2.9 mm; simultaneous augmentation, 3.3 ± 2.5 mm; staged preservation, 5.5 ± 1.7 mm; and staged augmentation, 3.5 ± 1.9 mm. Ultimately, the use of carbonated apatite alone as a bone graft material in implant therapy resulted in stable and favorable bone regeneration.

The role of body mass index on survivorship and clinical outcomes in total shoulder arthroplasty

BACKGROUND

Increased body mass index (BMI) is a potential risk factor for poorer outcomes and complications. However, the influence of BMI on the long-term outcomes of anatomic and reverse total shoulder arthroplasty (aTSA and rTSA) remains to be fully elucidated.

METHODS

Institutional records were queried to identify patients who underwent primary TSA between 2009-2020 with a minimum of 2 years of clinical follow-up. Retrospective review was performed to collect demographics, comorbidity status, and range of motion and strength measurements in forward elevation, external rotation, and internal rotation. Patients were called to obtain patient reported outcomes. Patients were stratified into 3 cohorts, by BMI: underweight or normal weight (U/NW, BMI≤25), overweight (OW, 2530).

RESULTS

Among 466 TSA patients, 245 underwent aTSA while 221 underwent rTSA. In the aTSA cohort, 40 were classified as U/NW, 72 as OW, and 133 as obese. Comparatively, the rTSA cohort was composed of 33 U/NW, 79 OW, and 209 obese patients. aTSA and rTSA patients had an average follow-up of 5.8±3.2 years and 4.5±2.3 years, respectively. No differences were found in age at surgery for the aTSA group (U/NW: 65.2±7.9 vs obese: 61.9±8.9 years; p=0.133), however, in the rTSA cohort, BMI was found to be inversely related to age at surgery (U/NW: 72.4±8.8 vs obese: 65.7±8.3 years; p<0.001). Across all BMI cohorts, patients saw great improvement in range of motion and strength. Postoperative patient reported outcomes for TSA did not vary by BMI in SANE, SST, VAS pain, and ASES scores. There was no significant difference in survival rates at 10-year follow-up in aTSA (U/NW: 95.8% vs obese: 93.2%; p=0.753) or rTSA (U/NW: 94.7% vs obese: 94.5%; p=0.791).

CONCLUSION

With dramatic improvements in range of motion, minimal differences in patient reported outcomes, and high rates of implant survival, TSA is a safe and effective treatment option for all patients, including for overweight and obese patients.

Rat Peri-implantitis Models: A Systematic Review and Meta-analysis

PURPOSE

To review experimental peri-implantitis studies using rat models and summarize different peri-implantitis induction techniques and evaluate their effectiveness.

MATERIALS AND METHODS

Electronic searches were conducted by two independent examiners to address the following issues. Meta-analyses explored the marginal bone loss (MBL) of four types of peri-implantitis induction methods in rats. The detailed induction tactics-such as the implant design, implant size, surgical process, time cost, induction methods, and endpoint measurements-were summarized.

RESULTS

Of the 18 included studies, 38.9% of the studies placed implants at the maxillary first molar, and 44.4% placed them at the alveolar ridge region anterior to the maxillary first molar. As for the induction method, the numbers of published studies on ligature methods, bacterial inoculation, and bacterial lipopolysaccharide inoculation were equally high among all selected studies. The total implant survival rate at the end was 160 out of 213 implants (75.11%). Eight studies with high pooled heterogeneity (I2 = 98, P < .01) in the meta-analysis reported an overall MBL (μ-CT) of 0.47 mm (95% CI = 0.14 to 0.81). A subgroup analysis estimated an MBL of 0.31 mm (95% CI = 0.12 to 0.50) for bacterial inoculation and 0.66 mm (95% CI = 0.07 to 1.26) for the ligature method. Histopathologic analysis revealed that peri-implantitis in rats was similar to peri-implantitis lesions in humans.

CONCLUSIONS

Implant placement at the maxillary first molar with bacterial inoculation and the silk ligature method to build peri-implantitis rat models is reliable to use for research on peri-implantitis.

Intracortical brain-computer interfaces for improved motor function: a systematic review

In this systematic review, we address the status of intracortical brain-computer interfaces (iBCIs) applied to the motor cortex to improve function in patients with impaired motor ability. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 Guidelines for Systematic Reviews. Risk Of Bias In Non-randomized Studies - of Interventions (ROBINS-I) and the Effective Public Health Practice Project (EPHPP) were used to assess bias and quality. Advances in iBCIs in the last two decades demonstrated the use of iBCI to activate limbs for functional tasks, achieve neural typing for communication, and other applications. However, the inconsistency of performance metrics employed by these studies suggests the need for standardization. Each study was a pilot clinical trial consisting of 1-4, majority male (64.28 %) participants, with most trials featuring participants treated for more than 12 months (55.55 %). The systems treated patients with various conditions: amyotrophic lateral sclerosis, stroke, spinocerebellar degeneration without cerebellar involvement, and spinal cord injury. All participants presented with tetraplegia at implantation and were implanted with microelectrode arrays via pneumatic insertion, with nearly all electrode locations solely at the precentral gyrus of the motor cortex (88.88 %). The development of iBCI devices using neural signals from the motor cortex to improve motor-impaired patients has enhanced the ability of these systems to return ability to their users. However, many milestones remain before these devices can prove their feasibility for recovery. This review summarizes the achievements and shortfalls of these systems and their respective trials.

Biomechanical evaluation of a new intramedullary nail compared with proximal femoral nail antirotation and InterTAN for the management of femoral intertrochanteric fractures

Purpose: Surgical treatment is the main treatment method for femoral intertrochanteric fractures (FIFs), however, there are lots of implant-related complications after surgery. Our team designed a new intramedullary nail (NIN) to manage such fractures. The purpose of this study was to introduce this new implant and compare it with proximal femoral nail antirotation (PFNA) and InterTAN for treating FIFs. Methods: An AO/OTA 31-A1.3 FIF model was built and three fixation models were created via finite element method, comprising PFNA, InterTAN, and the NIN. Vertical, anteroposterior (A-P) bending, and torsional loads were simulated and applied to the three fixation models. Displacement and stress distribution were monitored. In order to compare PFNA and the NIN deeply, finite element testing was repeated for five times in vertical load case. Results: The finite element analysis (FEA) data indicated that the NIN possessed the most outstanding mechanical properties among the three fixation models. The NIN model had lower maximal stress at implants compared to PFNA and InterTAN models under three load conditions. The trend of maximal stress at bones was similar to that of maximal stress at implants. Besides, the NIN model showed smaller maximal displacement compared with PFNA and InterTAN models under vertical, A-P bending, and torsional load cases. The trend for maximal displacement of fracture surface (MDFS) was almost identical with that of maximal displacement. In addition, there was significant difference between the PFNA and NIN groups in vertical load case (p < 0.05). Conclusion: Compared with PFNA and InterTAN, the NIN displayed the best mechanical properties for managing FIFs, including the lowest von Mises stress at implants and bones, and the smallest maximal displacement and MDFS under vertical, A-P bending, and torsional load cases. Therefore, this study might provide a new choice for patients with FIFs.

Impacts of economic factors influencing net returns of beef feedlot heifers administered two implant programs and fed for differing days-on-feed from pooled randomized controlled trials

The objective of this research was to evaluate the effects of two implant programs and differing days-on-feed (DOF) on net returns of beef feedlot heifers using sensitivity analyses of key economic factors. Crossbred beef heifers [n = 10,583; initial weight 315 kg (± 20.1 SD)] were enrolled across three trials (one Kansas, two Texas feedlot trials). Heifers were blocked by arrival and randomly allocated to one of six pens, resulting in a total of 144 pens and 24 blocks. Pen was randomly assigned to treatment as a 2 × 3 factorial. Implant programs were: IH + 200-Revalor-IH at initial processing, and a terminal implant after approximately 90 DOF (Revalor-200), or, XH-a single implant at initial processing (Revalor-XH). The DOF treatments were: heifers fed to a standard baseline endpoint (BASE) or heifers fed for an additional + 21 or + 42 d beyond BASE. Pen-level partial budgets were used for economic sensitivity analyses, which varied price points of single pricing components with all other components fixed. Variable components were live-fed cattle prices, base carcass prices (i.e., dressed), Choice-Select spread (CS-spread), and feed and yardage prices (FYP). For each, a Low, Mid-Low, Middle, Mid-High, and High price was chosen. Linear mixed models were fit for statistical analyses (α = 0.05). There were no significant two-way interactions (P-values ≥ 0.14). Regardless of the variable component evaluated, XH heifers had poorer net returns than IH + 200 at all prices (P ≤ 0.04). Selling live, the + 21 and (or) + 42 heifers had lower net returns than BASE at every fed cattle price point (P < 0.01). Selling dressed, the + 21 and (or) + 42 heifers had lower returns than BASE at Low, Mid-Low, and Middle fed cattle base prices (P < 0.01); there were no significant DOF differences at Mid-High, or High prices (P ≥ 0.24). Net returns were lower for + 42 than BASE at all CS-spreads (P ≤ 0.03), while BASE and + 21 did not differ significantly. Longer DOF had lower net returns than BASE when selling live at every FYP (P < 0.01) except at the Low price (P = 0.14). Selling dressed, there was no significant effect of DOF at Low or Mid-Low FYP (P ≥ 0.11); conversely, extended DOF had lower net returns than BASE at Middle, Mid-High, and High FYP (P < 0.01). Overall, there was minimal economic evidence to support extending feedlot heifer DOF beyond the BASE endpoint, and when feeding longer, larger reductions in return were observed when marketing live as opposed to dressed.

Human Gingival Fibroblast Growth and Function in Response to Laser-Induced Meso-and Microscale Hybrid Topography on Dental Implant Healing Abutments

PURPOSE

Laser-created titanium surface topographies enhance soft tissue attachment and implant stability. However, knowledge about the underlying mechanisms governing the tissue-level reaction is lacking. The objective of this study was to examine the behavior and function of human gingival fibroblasts growing on healing abutments with or without laser-textured topography.

MATERIALS AND METHODS

Human primary gingival connective tissue fibroblasts were cultured on healing abutments with machined or laser-textured (Laser-Lok, BioHorizons) surfaces. Cellular and molecular responses were evaluated by cell density assay (WST-1), fluorescence microscopy, qRT-PCR, and detachment test.

RESULTS

The machined surface showed mono-directional traces and scratches from milling, whereas the laser-textured surface showed a distinct morphology consisting of mono-directional meso-scale channels (15 μm pitch) and woven, oblique micro-ridges formed within the channel. There were no differences in initial fibroblast attachment, subsequent fibroblast proliferation, nor collagen production between the machined and laser-textured surfaces. Fibroblasts growing on laser-textured surface spread mono-directionally along the meso-channels, while cells growing on machined surfaces spread randomly. Fibroblasts on laser-textured surfaces were 1.8-times more resistant to detachment than those on machined surfaces. An adhesive glycoprotein (fibronectin) and trans-membrane adhesion linker gene (integrin beta-1) were upregulated on laser-textured surfaces.

CONCLUSIONS

The increased fibroblast retention, uniform growth, increased transcription of cell adhesion proteins compellingly explain the enhanced tissue-level response to laser-created, hybrid textured titanium surfaces. These results provide a cellular and molecular rationale for the tissue reaction to this unique surface and support its extended use from implant fixtures and healing abutments to diverse prosthetic components where enhanced soft tissue responses would be desirable.

Human Breast Cancer Cell Lines Differentially Modulate Signaling from Distant Microenvironments, Which Reflects Their Metastatic Potential

Metastasis is the stage at which the prognosis substantially decreases for many types of cancer. The ability of tumor cells to metastasize is dependent upon the characteristics of the tumor cells, and the conditioning of distant tissues that support colonization by metastatic cells. In this report, we investigated the systemic alterations in distant tissues caused by multiple human breast cancer cell lines and the impact of these alterations on the tumor cell phenotype. We observed that the niche within the lung, a common metastatic site, was significantly altered by MDA-MB-231, MCF7, and T47 tumors, and that the lung microenvironment stimulated, to differing extents, an epithelial-to-mesenchymal transition (EMT), reducing proliferation, increasing transendothelial migration and senescence, with no significant impact on cell death. We also investigated the ability of an implantable scaffold, which supports the formation of a distant tissue, to serve as a surrogate for the lung to identify systemic alterations. The scaffolds are conditioned by the primary tumor similarly to the lung for each tumor type, evidenced by promoting a pro-EMT profile. Collectively, we demonstrate that metastatic and non-metastatic breast cancers condition distant tissues, with distinct effects on tumor cell responses, and that a surrogate tissue can distinguish the metastatic potential of human breast cancer cell lines in an accessible site that avoids biopsy of a vital organ.

Balanced-force shim system for correcting magnetic-field inhomogeneities in the heart due to implanted cardioverter defibrillators

Background

In the US, 1.4 million people have implanted ICDs for reducing the risk of sudden death due to ventricular arrhythmias. Cardiac MRI (cMR) is of particular interest in the ICD patient population as cMR is the optimal imaging modality for distinguishing cardiac conditions that predispose to sudden death, and it is the best method to plan and guide therapy. However, all ICDs contain a ferromagnetic transformer which imposes a large inhomogeneous magnetic field in sections of the heart, creating large image voids that can mask important pathology. A shim system was devised to resolve these ICD issues. A shim coil system (CSS) that corrects ICD artifacts over a user-selected Region-of-Interest (ROI), was constructed and validated.

Methods

A shim coil was constructed that can project a large magnetic field for distances of ~15 cm. The shim-coil can be positioned safely anywhere within the scanner bore. The CSS includes a cantilevered beam to hold the shim coil. Remotely controlled MR-conditional motors allow 2 mm-accuracy three-dimensional shim-coil position. The shim coil is located above the subjects and the imaging surface-coils. Interaction of the shim coil with the scanner's gradients was eliminated with an amplifier that is in a constant current mode. Coupling with the scanners' radio-frequency (rf) coils, was reduced with shielding, low-pass filters, and cable shield traps. Software, which utilizes magnetic field (B0) mapping of the ICD inhomogeneity, computes the optimal location for the shim coil and its corrective current. ECG gated single- and multiple-cardiac-phase 2D GRE and SSFP sequences, as well as 3D ECG-gated respiratory-navigated IR-GRE (LGE) sequences were tested in phantoms and N = 3 swine with overlaid ICDs.

Results

With all cMR sequences, the system reduced artifacts from >100 ppm to <25 ppm inhomogeneity, which permitted imaging of the entire left ventricle in swine with ICD-related voids. Continuously acquired Gradient recalled echo or Steady State Free Precession images were used to interactively adjust the shim current and coil location.

Conclusion

The shim system reduced large field inhomogeneities due to implanted ICDs and corrected most ICD-related image distortions. Externally-controlled motorized translation of the shim coil simplified its utilization, supporting an efficient cardiac MRI workflow.

Synergistic Effect of Nano Strontium Titanate Coating and Ultraviolet C Photofunctionalization on Osteogenic Performance and Soft Tissue Sealing of poly(ether-ether-ketone)

This study aimed to evaluate the bioactivity of poly(ether ether ketone) (PEEK) after surface modification by persistent photoconductive strontium titanate (SrTiO3) magnetron sputtering and ultraviolet (UV) C irradiation. According to the different modifications, the PEEK specimens were randomly divided into five groups (n = 38/group): PEEK, Sr100-PEEK, Sr200-PEEK, UV/PEEK, and UV/Sr200-PEEK. Then, the specimens of Sr100-PEEK and Sr200-PEEK groups were, respectively, coated with 100 and 200 nm thickness photocatalyst SrTiO3 on the PEEK surface by magnetron sputtering. Subsequently, UV-C light photofunctionalized the specimens of PEEK and Sr200-PEEK groups to form UV/PEEK and UV/Sr200-PEEK groups. The specimens were characterized by a step meter, scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDX), and a water contact angle meter. The release test of the Sr ion was performed by inductively coupled plasma mass spectrometry (ICP-MS). In vitro study, osteogenic activity (MC3T3-E1 osteoblast-like cells) and epithelial and connective tissue attachment (gingival epithelial cells GE1 and fibroblasts NIH3T3) were analyzed in five groups. Surface morphology of the specimens was changed after coating, and the Sr content on the Sr-PEEK surface was increased with increasing coating thickness. In addition, the contact angle was increased significantly after magnetron sputtering. After UV-C photofunctionalization, the content of surface elements changed and the contact angle was decreased. The release of Sr ion was sustained, and the final cumulative release amount did not exceed the safety limit. In vitro experiments showed that SrTiO3 improved the cell activity of MC3T3-E1 and UV-C irradiation further enhanced the osteogenic performance of PEEK. Besides, UV-C irradiation also significantly promoted the cell viability, development, and expression of adhesion proteins of GE1 and NIH3T3 on PEEK. The present investigation demonstrated that nano SrTiO3 coating with UV-C photofunctionalization synergistically enhanced the osteogenic properties and soft tissue sealing function of PEEK in vitro.

Characterization of residual debris on packaged hip arthroplasty stems demonstrates the dominance of less than 10 μm sized particulate: Updated USP788 guidelines for orthopedic implants

Past evaluation of particle contamination on packaged implants has typically been conducted using US Pharmacopeia (USP) 788, a 1970s pharmaceutical guideline created to evaluate contaminant particles in injectable fluids and syringes. Our objective was to reestablish relevant acceptance criteria for residual orthopedic and other implant debris, including smaller particles (i.e., <10 μm in diameter). Packaged total hip arthroplasty (THA) titanium (Ti6Al4V)-alloy femoral stems were used (hydroxyapatite [HA]-coated and non-coated stems). Short-term ultrasonication and longer-term 24-hour soak/agitation methods were used to elute surface-bound contaminant particles, and released particles were analyzed via scanning electron microscopy, energy-dispersive x-ray analysis, image analysis, and particle characterization. For HA-coated THA-stems, >99% of eluted particles were calcium phosphate. For plain non-coated THA-stems, >99% of eluted particles were titanium-alloy-based. The number-based median size of particles in both groups was approximately 1.5 μm in diameter despite being composed of different materials. The total volume of particulate removed from HA-coated stems was 0.037 mm3 (671 × 103 particles total), which was approximately >50-fold more volume than that on plain non-coated stems at 0.0006 mm3 (89 × 103 particles total). Only non-coated THA stems passed reestablished USP788 acceptance criteria, compared by using equivalent total volumes of contaminant particulate within new and legacy guideline ranges of >10 and >25 μm ECD, that is, <1.0 × 107 particles for <1 μm diameter in size, <600,000 for <1-10 μm, <6000 for 10-25 μm and <600 for >25 μm. These results fill a knowledge gap on how much residual debris can be expected to exist on packaged implants and can be used as a basis for updating acceptance criteria (i.e., termed USP788-Implant [USP788-I]). Residual implant particulate assessment is critical given the increasing implant complexity and new manufacturing techniques (e.g., additive manufacturing).

Incidence of Nonunion of the First Metatarsophalangeal Joint Arthrodesis After Failed Implant Arthroplasty: A Systematic Review

Joint arthroplasty of the first metatarsophalangeal (MTP) joint is an accepted surgical option for patients with hallux rigidus. However, this procedure has been reported to have a high complication rate and unpredictable survivorship. Implant arthroplasty failure is a devastating complication that results in significant osseous defect with altered biomechanics of the foot. Commonly, salvage options are limited to arthrodesis with bone grafting. However, outcomes are rarely reported. The purpose of this study is to investigate the fusion rates of first metatarsophalangeal joint arthrodesis after conversion from failed implant arthroplasty. A systematic review of electronic databases to find reports of conversion arthrodesis after failed implant arthroplasty was performed. Six studies involving a total of 76 patients with a weighted mean age of 54.9 met the inclusion criteria. Out of the 6 included articles, the nonunion rate was 16.5% at a weighted mean follow-up of 48.1 months. The nonunion rate in the current report is higher than reported nonunion rates of primary arthrodesis. More prospective studies with consistent and standard outcome measures are needed to further determine the success rate of this salvage procedure.Levels of Evidence: 4, Systematic Review of Level 4 Studies.

Clinical and CBCT Assessment of Role of Bisphosphonate on Osteotomy Site and Implant Surface

Objectives

To assess the role of bisphosphonate on osteotomy site and implant surface.

Materials and Methods

Twenty patients with adequate width and height of edentulous space and a single missing posterior tooth between the ages of 25 and 55 were incorporated in this research. Ten participants received implant therapy alone; the other ten patients received implant therapy and bisphosphonate application to osteotomy site and the implant surface.

Result

Changes in the crestal bone level were seen in both the study and control groups. At 1 year, crestal bone loss was less in the bisphosphonate-treated group than in the control group.

Conclusion

The quantity of crestal bone loss was reduced when bisphosphonate (sodium alendronate) was applied locally near the implant and osteotomy site.

Reversible Mechanical Contraception and Endometriosis Treatment Using Stimuli-Responsive Hydrogels

Female sterilization via fallopian tube ligation is a common procedure; However, after the operation, over 10% of women seek re-fertilization, which is frequently unsuccessful. In addition, there is evidence that fallopian tubes contribute to the spread of endometriotic tissue as they serve as channels for proinflammatory media entering the abdominal cavity via retrograde menstruation. Here, stimuli-degradable hydrogel implants are presented for the functional, biocompatible, and reversible occlusion of fallopian tubes. The hydrogel implants, designed with customized swelling properties, mechanically occlude fallopian tubes in a high-performance manner with burst pressures reaching 255-558 mmHg, exceeding normal abdominal pressures (95 mmHg). Their damage-free removal can be achieved within 30 min using near-visible UV light or a glutathione solution, employing a method akin to standard fallopian tube perfusion diagnostics. Ultrasound-guided implant placement is demonstrated using a clinical hysteroscope in a human-scale uterus model and biocompatibility in a porcine in vivo model. Importantly, the prevention of live sperm as well as endometrial cell passage through blocked fallopian tubes is demonstrated. Overall, a multifunctional system is presented that constitutes a possible means of on-demand, reversible contraception along with the first-ever mechanical approach to abdominal endometriosis prevention and treatment.

Evaluation of Type, Nature, and Prevalence of Common Oral Pathology Lesions Involving Periodontium and Implant in Patients of Tertiary Level Dental Hospital in Hazaribagh City, Jharkhand

Background

Evaluation of type, nature, and prevalence of common oral pathology lesions involving periodontium and implant in patients of tertiary level dental hospital in Hazaribagh City, Jharkhand.

Materials and Methods

A total of 2467 people were requested to take part in the oral examination. The current study cohort was made up of the 62.4% of the initial subgroup who participated in the clinical oral examination and granted their agreement for the use of the data. Between January 2023 and June 2023, the clinical oral examination was completed.

Results

No changes were observed in 89.6% of study participants. 88.2% males had no changes while 90.4% females had no changes. Normal variations were observed in 3.4% of study participants. 4.3% males had normal variations while 2.7% females had normal variations. Infectious oral pathology was observed in 3.3% of study participants. 2.4% males had infectious oral pathology while 3.2% females had infectious oral pathology Ulcerative lesions were observed in 4.1% of study participants. 3.6% males had ulcerative lesions while 2.4% females had ulcerative lesions. White lesions were observed in 6.7% of study participants. 8.2% males had white lesions while 5.6% females had white lesions.

Conclusion

This study provided a detailed evaluation of type, nature, and prevalence of different oral pathology lesions focusing on periodontium and implant.

Two-Year Survivorship and Patient-Reported Outcomes of a Prospectively Enrolled Cohort of INFINITY Total Ankle Arthroplasties

BACKGROUND

The INFINITY total ankle implant is a widely and successfully used option for total ankle arthroplasty. The purpose of this study is to assess the 2-year survivorship, complication rates, patient-reported outcomes, and radiologic findings of prospectively enrolled patients undergoing a fixed-bearing total ankle arthroplasty (TAA). This study sought to determine if factors such as traditional vs patient-specific instrumentation, preoperative degree of arthritis, deformity, or etiology of arthritis impact surgical or clinical outcomes.

METHODS

A total of 143 prospectively enrolled patients (148 ankles) underwent TAA with a fixed-bearing total ankle implant between 2017 and 2019 at 9 different institutions by 9 different surgeons. A total of 116 completed 2-year follow-up. Patients were stratified by instrumentation used, degree of preoperative deformity, the Canadian Orthopaedic Foot and Ankle Society (COFAS) grading system, and etiology of arthritis. Outcomes used included implant survivorship and adverse events within 2 years of surgery. Additionally, patient-reported outcomes and radiographs were collected at 6-month, 1-year, and 2-year postoperatively. PROMs used included Ankle Osteoarthritis Score (AOS), Patient-Reported Outcomes Measurement Information System (PROMIS) global health score, the Foot and Ankle Outcome Score (FAOS), and patient satisfaction (rated from excellent to poor).

RESULTS

Implant survivorship at 2 years was 97.79%. There were 17 reoperations (11.5%), with 4 of the implants requiring revision (2.7%). Significant improvements in all PROMs were observed among all subgroups at all postoperative time points without significant variation between subgroups. Patients classified as COFAS type 2 arthritis preoperatively demonstrated significantly more improvement in FAOS Total Symptom Score at the 1- and 2-year measurements than COFAS type 3 patients at both time points.

CONCLUSION

Total ankle arthroplasty with a fixed-bearing implant system is a safe and reliable treatment option for patients with end-stage arthritis regardless of degree of deformity or COFAS grading.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Long-Term Clinical Outcomes of Single Crowns or Short Fixed Partial Dentures Supported by Short (≤6 mm) Dental Implants: A Systematic Review

Long-term clinical outcomes of short dental implants (≤6 mm) supporting single crowns or short fixed partial dentures have been reported differently in different studies and need more clarification. This systematic study evaluated the rate of bone loss (BL), the durability of implants equal to or shorter than 6 mm supporting single crowns or short fixed partial dentures, and prosthetic-related side effects during 5 years of follow-up. Five databases (PubMed, MEDLINE, Scopus, Google Scholar, and Cochrane) were electronically and manually searched for longitudinal studies with a follow-up period of 5 years or more until January 2023. The study question was, "Does the implant equal to or shorter than 6 mm affect BL and survival rate of the implant-supported prosthesis after 5 years of follow-up?". From 752 identified articles, nine studies were selected for further evaluation. After 5 years of follow-up, most studies had more than 90% survival rate and the maximum BL was 0.54 mm. Still, in internal and external connections, these changes were not substantial. For example, screw loosening was the most common problem with implanted prostheses. Implants of 6 mm or shorter are a suitable treatment option in atrophic ridges with good durability and fewer side effects during a follow-up period of more than 5 years.

A CBCT Assessment of Orthodontic Mini-Implant Placement

Objectives

This study compares the precision of cone beam computed tomography (CBCT) and two-dimensional radiography for mini-implant implantation.

Materials and Method

For 30 sites (in 15 patients between the ages of 13 and 26 years), the buccal interradicular region among the 2nd premolar and 1st molar was found to be the best location for mini-implants. Next, two groups of the mini-implant implantation process were created. Mini-implants were positioned at the CBCT data-identified sites in the CBCT group. Mini-implants were inserted in the RVG group by using two-dimensional digital radiography and a specially constructed guide. To assess the precision of the mini-implant implantation, post-placement CBCT images were acquired. The obtained data were statistically analyzed.

Result

The two groups showed a statistically considerable variation in the mini-implant placement's departure from the optimal height. Due to the smaller interradicular space and decreased convenience in the posterior mandibular area, two out of 15 mini-implants in the RVG group demonstrated root contact in the mandibular jaw.

Conclusion

The two-dimensional intraoral radiograph of the interradicular area provides sufficient information for mini-implant placement even though CBCT accurately visualizes the interradicular space in three dimensions.

Impact of the Habit of Alcohol Consumption on the Success of the Implants: A Retrospective Study

Introduction

A recent study has demonstrated that social factors have an impact on the condition of dental implants. The present investigation investigated how varied alcohol intake quantities might alter the condition of dental implants and related peri-implant inflammation.

Materials and Methods

This retrospective research was piloted in a tertiary care center, and implants inserted between 2010 and 2022 were evaluated through a retrospective cohort analysis. Within 3 months following implant implantation, information on alcohol intake was gathered from the health maintenance records and employed as the predictor variable. The implant results as well as peri-implantitis were examined at follow-up visits. Using the logistic regression model, the Wald test analysis analyzed the statistical consequences of each parameter. The findings were translated using an odds ratio that was determined with a 95% confidence level. The data were generated and analyzed using descriptive statistics, with statistical significance defined as P < 0.05.

Results

At the time of implant placement, the enrolled patients were 59 ± 11.3 years old on average. The median time before peri-implantitis occurred was 31.3 ± 22.2 months. Within the first 2 years following implant implantation, the majority of people experienced peri-implantitis. The incidence of peri-implantitis was the lowest among light and moderate alcoholics (11.5%) and the highest among heavy alcoholics (46.2%). Moderate alcohol use was associated with a 79.1% decrease in peri-implantitis when compared to not drinking (P = 0.0365), whereas light alcohol consumption was connected to a 51.3% decrease (P = 0.026). The incidence of peri-implantitis among heavy drinkers was significantly significant (P = 0.0001).

Conclusion

According to the findings of the current retrospective cohort analysis, drinking alcohol at mild-to-moderate levels is connected to a reduction in the incidence rate of peri-implantitis compared to heavy drinkers. In contrast, high alcohol consumption was found to be associated with an increase in the prevalence of peri-implantitis among the participants who had dental implants.

Assessment of Role of Bisphosphonates on Dental Implant Treatment in Post-menopausal Ladies

Objectives

To examine the impact of bisphosphonates (BPs) on dental implant treatment and alveolar bone in post-menopausal ladies.

Materials and Methods

Twenty post-menopausal ladies who had at least one dental implant within the previous 5 years participated in the current study. Ten subjects were categorized into two groups: Group A had BP medication for 1.5 years, and group B received parathyroid hormone (PTH). Both groups' bone thickness and bone mineral density (BMD) were measured.

Result

Group A had 5%, and group B had 5% of dental implants failures. BMD of cortical bone was 1468 ± 136 mg/mL and 1008 ± 84 mg/mL in groups A and B, correspondingly. The cortical and cancellous bone densities in both the groups were statically significant. Cortical bone thickness was insignificant in comparison.

Conclusion

Both cortical and cancellous bones' bone mineral density decreased in both groups. With continued usage of BPs, the cortical bone thickness increased.

Radiographic Evaluation in Implant Patients: A Review

Diagnostic imaging is crucial in assessing dental implant patients. The height, width, and shape of the bone are precisely depicted and measured by these tests, which help pinpoint the locations of significant anatomical structures adjacent to the implant placement sites. The type of implant to be utilized, the positioning of the remaining dentition, and the degree to which bone quality or quantity is in question all play a role in determining the radiologic approach that is most suited for a given patient. This review is an update on the current knowledge in the field of radiographic evaluation in implant placement. Considering the radiation exposure and the expense of each test, it is important to carefully determine whether pre-implant imaging is acceptable in each situation. Although multislice computed tomography is the gold standard from the authors' perspective, not every implant situation can justify such a test.

Treatment of Residual Palatal Collapse in Hypoglossal Nerve Stimulation Using a Palatal Device

Hypoglossal nerve stimulation (HNS) has increasingly become an alternative therapy for obstructive sleep apnea patients with CPAP intolerance. Stimulation of the hypoglossal nerve during sleep enhances airway patency and alleviates collapse. Suboptimal responses to HNS often stem from insufficient palatal coupling and residual velar collapse. Combining palatal devices, such as Velumount®, with HNS represents a simple and cost-effective strategy to treat residual palatal collapse. Patients desiring conservative treatment for residual palatal obstruction under HNS may consider this combined approach. Laryngoscope, 2024.

Balancing beauty and science: a review of facial implant materials in craniofacial surgery

Facial reconstruction and augmentation, integral in facial plastic surgery, address defects related to trauma, tumors infections, and congenital skeletal deficiencies. Aesthetic considerations, including age-related facial changes, involve volume loss and diminished projection, often associated with predictable changes in the facial skeleton. Autologous, allogeneic, and alloplastic implants are used to address these concerns. Autologous materials such as bone, cartilage, and fat, while longstanding options, have limitations, including unpredictability and resorption rates. Alloplastic materials, including metals, polymers, and ceramics, offer alternatives. Metals like titanium are biocompatible and used primarily in fracture fixation. Polymers, such as silicone and polyethylene, are widely used, with silicone presenting migration, bony resorption, and visibility issues. Polyethylene, particularly porous polyethylene (MedPor), was reported to have one of the lowest infection rates while it becomes incorporated into the host. Polyether-ether-ketone (PEEK) exhibits mechanical strength and compatibility with imaging modalities, with custom PEEK implants providing stable results. Acrylic materials, like poly-methylmethacrylate (PMMA), offer strength and is thus mostly used in the case of cranioplasty. Bioceramics, notably hydroxyapatite (HaP), offer osteoconductive and inductive properties, and HaP granules demonstrate stable volume retention in facial aesthetic augmentation. Combining HaP with other materials, such as PLA, may enhance mechanical stability. 3D bioprinting with HaP-based bioinks presents a promising avenue for customizable and biocompatible implants. In conclusion, various materials have been used for craniofacial augmentation, but none have definitively demonstrated superiority. Larger randomized controlled trials are essential to evaluate short- and long-term complications comprehensively, potentially revolutionizing facial balancing surgery.

Early removal of the etonogestrel contraceptive implant in Spanish women: a prospective cohort study

Purpose

To know the discontinuation rate and characterize predictors and reasons of contraceptive implant removal within 12 months of insertion in our community setting.

Methods

This prospective cohort study included women receiving the etonogestrel contraceptive implant at sexual and reproductive health centers between September 2019 and September 2020. The variables collected were implanted insertion timing, reproductive and demographic characteristics, medical conditions, sexual activity and counseling. Our primary outcome was implant discontinuation. Kaplan-Meier survival curves were used to show the cumulative discontinuation rate of implants contraceptive within the first year of insertion. We also identified factors that increased the risk of implant removal using the log-rank test and the Cox regression model. Reasons for discontinuation were documented.

Results

199 women were followed up. Implant discontinuation was documented in 17.1% of implant users prior to 12 months. Factors that increase the risk of implant removal are living with a partner, being aged 25-34 years and not receiving comprehensive and structured counseling from the midwife. The main reason for removal was unsatisfactory bleeding (97.1%), but this was combined with other reasons such as cessation of sexual intercourse (58.8%), worsening mood (58.8%), weight gain (55.9%) or decreased libido (50.0%).

Conclusion

The rate of discontinuous implant uses in the first year is relevant in relation to cost-effectiveness, there is room for improvement that should not be overlooked. Comprehensive and structured midwife-led counseling can reduce early implant abandonment removal. The development in different countries of the role of midwives in the management of contraceptives can contribute to the economic benefit of health services and the satisfaction of women.

Bacterial Surface Appendages Modulate the Antimicrobial Activity Induced by Nanoflake Surfaces on Titanium

Bioinspired nanotopography is a promising approach to generate antimicrobial surfaces to combat implant-associated infection. Despite efforts to develop bactericidal 1D structures, the antibacterial capacity of 2D structures and their mechanism of action remains uncertain. Here, hydrothermal synthesis is utilized to generate two 2D nanoflake surfaces on titanium (Ti) substrates and investigate the physiological effects of nanoflakes on bacteria. The nanoflakes impair the attachment and growth of Escherichia coli and trigger the accumulation of intracellular reactive oxygen species (ROS), potentially contributing to the killing of adherent bacteria. E. coli surface appendages type-1 fimbriae and flagella are not implicated in the nanoflake-mediated modulation of bacterial attachment but do influence the bactericidal effects of nanoflakes. An E. coli ΔfimA mutant lacking type-1 fimbriae is more susceptible to the bactericidal effects of nanoflakes than the parent strain, while E. coli cells lacking flagella (ΔfliC) are more resistant. The results suggest that type-1 fimbriae confer a cushioning effect that protects bacteria upon initial contact with the nanoflake surface, while flagella-mediated motility can lead to elevated membrane abrasion. This finding offers a better understanding of the antibacterial properties of nanoflake structures that can be applied to the design of antimicrobial surfaces for future medical applications.