Patient-specific Implants Research Articles

Combining Patient-specific Implant With Malar Reduction to Repair Mid-facial Asymmetry Caused by Craniofacial Fractures in Asians.

Mid-facial asymmetry caused by bone defect or deformation resulted from craniofacial fracture was a common secondary complication needed to repair. Patient-specific implant (PSI) designed with the unaffected side as a template is a good choice to repair this kind of facial asymmetry. However, in Asians, the broad and prominent zygomatic bone in unaffected side is not an optimal template, because the oval facial shape was considered as a more attractive appearance in Asian esthetic concept. To repair the mid-facial asymmetry and to improve the facial contour, the authors combined PSI implantation with malar reduction in one-stage surgery. The authors referred the facial proportion index (the optimal ratio of mid and lower face was 1.27) as a basis for preoperative precise design to determine the ideal facial shape of unaffected side, and used mirror image overlay technique with the ideal shape of unaffected side as a template to design the PSI. With this surgical strategy, patients not only can repair facial asymmetry but also can get a more attractive appearance.

A 3D-printed patient-specific modular implants for pelvic reconstruction of bone tumors involving the sacroiliac joint.

Background: Current reconstruction methods of the pelvic ring after extensive resection of tumors involving the sacroiliac joint have a high incidence of failure. We aimed to study the effect of 3D-printed patient-specific implant reconstruction to show that this method is stable and has a low risk of failure. Methods: Between February 2017 and November 2021, six patients with bone tumors involving the sacroiliac joint (Enneking I + IV) who received 3D-printed patient-specific implants for pelvic reconstructive surgery were retrospectively analyzed. Two female and four male patients with a mean age of 41.83years (range 25-65years) were included. Two were osteosarcomas, two chondrosarcomas, one malignant fibrous histiocytoma, and one giant cell tumor of bone. For each patient, preoperative osteotomy guides were designed to ensure accurate tumor resection and individualized prostheses were designed to ensure a perfect fit of the bone defect. General, oncologic, and functional outcomes, implant status, and complications were retrospectively analyzed. The Visual Analog Scale (VAS) was used to assess pain and the Musculoskeletal Tumor Society (MSTS) score was used to assess hip function. Osseointegration was assessed by CT. Results: According to the preoperative design, complete resection of the entire tumor and reconstruction with a custom 3D-printed sacroiliac joint implant was completed without perioperative severe complications or deaths. Relatively satisfactory surgical margins were achieved. The mean operative time and intraoperative blood loss were 495min (420-600min) and 2533.33mL (range, 1,200-3,500mL), respectively. The mean follow-up was 49.83months (range, 18-75months). At the last follow-up, all four patients were disease-free, and the two patients who developed lung metastases were alive with tumors. All patients could walk unassisted. The mean VAS was 1.33 (range, 0-2). The mean MSTS score was 25.33 (range, 24-27). CT showed complete osseointegration of the implant to the ilium and sacrum. Conclusion: The 3D-printed custom prosthesis can effectively reconstruct pelvic stability after total sacroiliac joint resection with satisfactory clinical results.

Three-Dimensional Digital Technology: A Powerful Assistant for the Reconstruction of Complex Craniofacial Deformities.

Three-dimensional digital technology has been widely applied in craniofacial surgeries, particularly in conventional procedures such as facial contouring and orthognathic surgery. To some extent, the process has already been standardized. As to reconstruction surgeries of complex craniofacial deformity, however, surgical plans need to be patient-specific. Traditionally, individualized surgical treatment largely relies on the surgeon's clinical experience. The application of digital technology mainly focuses on preoperative planning and postoperative evaluation of surgical outcomes rather than intraoperative patient-specific implants or osteotomy guides. For patients with complex craniofacial deformities, requirements for accurate 3-dimensional digital technology can be much higher. This study presents a favorable surgical reconstruction of the severe craniofacial deformity using 3-dimensional digital technology, providing references for craniofacial surgeons, which could be beneficial to clinical practice and treatment efficacy.

Augmented and Virtual Reality for Preoperative Trauma Planning, Focusing on Orbital Reconstructions: A Systematic Review.

This systematic review summarizes recent literature on the use of extended reality, including augmented reality (AR), mixed reality (MR), and virtual reality (VR), in preoperative planning for orbital fractures. A systematic search was conducted in PubMed, Embase, Web of Science and Cochrane on 6 April 2023. The included studies compared extended reality with conventional planning techniques, focusing on computer-aided surgical simulation based on Computed Tomography data, patient-specific implants (PSIs), fracture reconstruction of the orbital complex, and the use of extended reality. Outcomes analyzed were technical accuracy, planning time, operative time, complications, total cost, and educational benefits. A total of 6381 articles were identified. Four articles discussed the educational use of VR, while one clinical prospective study examined AR for assisting orbital fracture management. AR was demonstrated to ameliorate the accuracy and precision of the incision and enable the better identification of deep anatomical tissues in real time. Consequently, intraoperative imaging enhancement helps to guide the orientation of the orbital reconstruction plate and better visualize the precise positioning and fixation of the PSI of the fractured orbital walls. However, the technical accuracy of 2-3 mm should be considered. VR-based educational tools provided better visualization and understanding of craniofacial trauma compared to conventional 2- or 3-dimensional images.

Mechanical behaviour of reconstructed defected skull with custom PEEK implant and Titanium fixture plates under dynamic loading conditions using FEM

Skull reconstruction using cranial implants is often required for repairing skull defects caused due to trauma, diseases, or malignancy to protect intracranial structures. For relieving Intracranial Pressure (ICP) surgeons restore cranial defects either using natural bones or fabricated custom cranial implants. With the increase in Traumatic Brain Injuries (TBI) and challenges faced by TBI patients to regain normalcy, it is imperative to analyse the mechanical behaviour of skull-implant assemblies under some Head Injury Criteria (HIC). Medical grade materials including Titanium Alloys (Ti-6Al-4V) and Polyether-ether-ketone (PEEK) are used by fabricating Patient-Specific Implants (PSI) manufactured using 3D imaging, modelling and printing techniques. 3D technologies are preferred over conventional manufacturing methods, as they enable fabrication of custom shapes, sizes and properties for these PSI.For an effective attachment of PSI with a defective skull, a stable joint and plate arrangement as fixture plates is necessary at their interface. These fixtures can have variable numbers, design shapes, materials and location arrangements.This paper presents the Finite Element Method/Analysis (FEM/FEA) study of PSI attached to a defected skull for reconstruction, with linear shaped fixture configuration, when subjected to an external dynamic loading at 5 m/s, strain rate of 10s−1 to 243s−1 and ICP of 15mm Hg from three sides of the skull faces. Three different materials as Neoprene (soft), Concrete (medium rigid) and E-Glass (highly rigid) have been used, in the form of a rectangular thin cuboidal wall structure, at an angle of 45° with the skull face. Four linear shaped fixture plates which were simplest to design, were used to attach the PSI-skull assembly, to ensure that weight of the PSI-fixation assembly on the patient remains minimal, overall assembly has symmetrical fixations and efforts required by a surgeon for fitment of these plates remain minimal. Placement of these fixture plates has been optimized to encompass the complete PSI-skull interface section, due to which the stresses within all the assembly components (PSI, fixture plate and skull) reduced by nearly 2.5 times than the initial design and remained within yielding limits, thereby, averting any failure under heavy external dynamic loading.

Clinical Stability of Bespoke Snowman Plates for Fixation following Sagittal Split Ramus Osteotomy of the Mandible.

Maxillofacial skeletal surgery often involves the use of patient-specific implants. However, errors in obtaining patient data and designing and manufacturing patient-specific plates and guides can occur even with accurate virtual surgery. To address these errors, bespoke Snowman plates were designed to allow movement of the mandible. This study aimed to compare the stability of bespoke four-hole miniplates with that of a bespoke Snowman plate for bilateral sagittal split ramus osteotomy (SSRO), and to present a method to investigate joint cavity changes, as well as superimpose virtual and actual surgical images of the mandible. This retrospective study included 22 patients who met the inclusion criteria and underwent orthognathic surgery at a university hospital between 2015 and 2018. Two groups were formed on the basis of the plates used: a control group with four-hole bespoke plates and a study group with bespoke Snowman plates. Stability was assessed by measuring the condyle-fossa space and superimposing three-dimensional virtual surgery images on postoperative cone-beam computed tomography (CBCT) scans. No significant differences were observed in the condyle-fossa space preoperatively and 1 year postoperatively between the control and study groups. Superimposing virtual surgery and CBCT scans revealed minimal differences in the landmark points, with no variation between groups or timepoints. The use of bespoke Snowman plates for stabilizing the mandible following SSRO exhibited clinical stability and reliability similar to those with bespoke four-hole plates. Additionally, a novel method was introduced to evaluate skeletal stability by separately analyzing the condyle-fossa gap changes and assessing the mandibular position.

The ideal patient specific implant. Part II: An eight step checklist for maxillary class I, II Brown defects

Patient specific implants (PSI) though considered the next frontier in Maxillofacial Reconstruction, the gold standard for Brown I, II maxillary defects still remains autogenous reconstruction. The authors in their previous papers have standardised the design of Patient Specific Implants for Brown I, II mandibular defects. In this paper they attempt to standardise the design of PSI for Brown I,II maxillary defects using a scientifically optimised design which has passed through a stringent set of parameters. They aim to address the complications like wound dehiscence, poor dimensional accuracy and unoptimised biomechanics due to lack of standardisation thus impeding it's widespread acceptance among the scientific community. This study presents an eight step checklist to be followed for designing of an ideal standardised patient specific implant and can serve as a go-to guide for the operating and designing team.

Predictors of Conduction Disturbances Requiring New Permanent Pacemaker Implantation following Transcatheter Aortic Valve Implantation Using the Evolut Series.

(1) Background: Conduction disturbance requiring a new permanent pacemaker (PPM) after transcatheter aortic valve implantation (TAVI) has traditionally been a common complication. New implantation techniques with self-expanding platforms have reportedly reduced the incidence of PPM. We sought to investigate the predictors of PPM at 30 days after TAVI using Evolut R/PRO/PRO+; (2) Methods: Consecutive patients who underwent TAVI with the Evolut platform between October 2019 and August 2022 at University Hospital Galway, Ireland, were included. Patients who had a prior PPM (n = 10), valve-in-valve procedures (n = 8) or received >1 valve during the index procedure (n = 3) were excluded. Baseline clinical, electrocardiographic (ECG), echocardiographic and multislice computed tomography (MSCT) parameters were analyzed. Pre-TAVI MSCT analysis included membranous septum (MS) length, a semi-quantitative calcification analysis of the aortic valve leaflets, left ventricular outflow tract, and mitral annulus. Furthermore, the implantation depth (ID) was measured from the final aortography. Multivariate binary logistic analysis and receiver operating characteristic (ROC) curve analysis were used to identify independent predictors and the optimal MS and ID cutoff values to predict new PPM requirements, respectively; (3) Results: A total of 129 TAVI patients were included (age = 81.3 ± 5.3 years; 36% female; median EuroSCORE II 3.2 [2.0, 5.4]). Fifteen patients (11.6%) required PPM after 30 days. The patients requiring new PPM at 30 days were more likely to have a lower European System for Cardiac Operative Risk Evaluation II, increased prevalence of right bundle branch block (RBBB) at baseline ECG, have a higher mitral annular calcification severity and have a shorter MS on preprocedural MSCT analysis, and have a ID, as shown on the final aortogram. From the multivariate analysis, pre-TAVI RBBB, MS length, and ID were shown to be predictors of new PPM. An MS length of <2.85 mm (AUC = 0.85, 95%CI: (0.77, 0.93)) and ID of >3.99 mm (area under the curve (AUC) = 0.79, (95% confidence interval (CI): (0.68, 0.90)) were found to be the optimal cut-offs for predicting new PPM requirements; (4) Conclusions: Membranous septum length and implantation depth were found to be independent predictors of new PPM post-TAVI with the Evolut platform. Patient-specific implantation depth could be used to mitigate the requirement for new PPM.

The Effectiveness of Three-Dimensional Osteosynthesis Plates versus Conventional Plates for the Treatment of Skeletal Fractures: A Systematic Review and Meta-Analysis.

To assess the difference between preformed anatomically shaped osteosynthesis plates and patient-specific implants versus conventional flat plates for the treatment of skeletal fractures in terms of anatomical reduction, operation time, approach, patient outcomes, and complications. MEDLINE (1950 to February 2023), EMBASE (1966 to February 2023), and the Cochrane Central Register of Controlled Trials (inception to February 2023) databases were searched. Eligible studies were randomised clinical trials, prospective controlled clinical trials, and prospective and retrospective cohort studies (n ≥ 10). Inclusion criteria were studies reporting the outcomes of preformed anatomically shaped osteosynthesis plates and patient-specific implants versus conventional flat plates after treating skeletal fractures. Outcome measures included anatomical reduction, stability, operation time, hospitalisation days, patients' outcomes, and complications. Two independent reviewers assessed the abstracts and analysed the complete texts and methodologies of the included studies. In total, 21 out of the 5181 primarily selected articles matched the inclusion criteria. A meta-analysis revealed a significant difference in operation time in favour of the preformed anatomical plates and patient-specific implants versus conventional plates. Significant differences in operation time were found for the orbital (95% CI: -50.70-7.49, p = 0.008), upper limb (95% CI: -17.91-6.13, p < 0.0001), and lower limb extremity groups (95% CI: -20.40-15.11, p < 0.00001). The mean difference in the rate of anatomical reduction in the lower limb extremity group (95% CI: 1.04-7.62, p = 0.04) was also in favour of using preformed anatomical plates and patient-specific implants versus conventional plates. This systematic review showed a significant mean difference in surgery time favouring the use of preformed anatomical plates and patient-specific implants for orbital, upper, and lower limb extremity fractures. Additionally, preformed anatomical plates and patient-specific implants in the lower limb group result in a significantly higher rate of anatomical reduction versus conventional flat plates.

3D printing for spine pathologies: a state-of-the-art review.

Three-Dimensional Printing has advanced throughout the years in the field of biomedical science with applications, especially in spine surgeries. 3D printing has the ability of fabricating highly complex structures with ease and high dimensional accuracy. The complexity of the spine's architecture and the inherent dangers of spinal surgery bring the evaluation of 3D printed models into consideration. This article summarizes the benefits of 3D printing based models for application in spine pathology. 3D printing technique is extensively used for fabrication of anatomical models, surgical guides and patient specific implants (PSI). The 3D printing based anatomical models assist in preoperative planning and training of students. Furthermore, 3D printed models can be used for improved communication and understanding of patients about the spinal disorders. The use of 3D printed surgical guides help in the stabilization of the spine during surgery, improving post procedural outcomes. Improved surgical results can be achieved by using PSIs that are tailored for patient specific needs. Finally, this review discusses the limitations and potential future scope of 3D printing in spine pathologies. 3D printing is still in its infancy, and further research would provide better understanding of the technology's true potential in spinal procedures.

PATIENT SPECIFIC IMPLANTS (PSI) IN MAXILLOFACIAL REHABILITATION- A SYSTEMATIC REVIEW

Patient-specific implant (PSI) is a personalized approach to reconstructive and esthetic surgery. This is particularly useful in maxillofacial surgery as well as prosthodontics, in which restoring the complex three-dimensional (3D) contour can be quite challenging. In certain situations, the best results can only be achieved with implants custom made to fit a particular need. Among the various alloplastic materials, polyether-ether ketone (PEEK) has emerged as an attractive option for the PSI. Significant progress has been made over the past decade in the design and manufacture of maxillofacial PSIs using additive manufacturing (AM) technology. This paper gives a brief review of Patient Specific Implants, its manufacturing, indications and materials used in maxillofacial surgery.

Development of patient-specific osteosynthesis including 3D-printed drilling guides for medial tibial plateau fracture surgery

PurposeA substantial proportion of conventional tibial plateau plates have a poor fit, which may result in suboptimal fracture reduction due to applied -uncontrolled- compression on the bone. This study aimed to assess whether patient-specific osteosyntheses could facilitate proper fracture reduction in medial tibial plateau fractures.MethodsIn three Thiel embalmed human cadavers, a total of six tibial plateau fractures (three Schatzker 4, and three Schatzker 6) were created and CT scans were made. A 3D surgical plan was created and a patient-specific implant was designed and fabricated for each fracture. Drilling guides that fitted on top of the customized plates were designed and 3D printed in order to assist the surgeon in positioning the plate and steering the screws in the preplanned direction. After surgery, a postoperative CT scan was obtained and outcome was compared with the preoperative planning in terms of articular reduction, plate positioning, and screw direction.ResultsA total of six patient-specific implants including 41 screws were used to operate six tibial plateau fractures. Three fractures were treated with single plating, and three fractures with dual plating. The median intra-articular gap was reduced from 6.0 (IQR 4.5–9.5) to 0.9 mm (IQR 0.2–1.4), whereas the median step-off was reduced from 4.8 (IQR 4.1–5.3) to 1.3 mm (IQR 0.9–1.5). The median Euclidean distance between the centre of gravity of the planned and actual implant was 3.0 mm (IQR: 2.8–3.7). The lengths of the screws were according to the predetermined plan. None of the screws led to screw penetration. The median difference between the planned and actual screw direction was 3.3° (IQR: 2.5–5.1).ConclusionThis feasibility study described the development and implementation of a patient-specific workflow for medial tibial plateau fracture surgery that facilitates proper fracture reduction, tibial alignment and accurately placed screws by using custom-made osteosynthesis plates with drilling guides.

Accuracy of maxillary positioning using computer-designed and manufactured occlusal splints or patient-specific implants in orthognathic surgery

ObjectiveTo determine the accuracy of maxillary positioning using computer-designed and manufactured occlusal splints or patient-specific implants in orthognathic surgery.Material and MethodsA retrospective analysis of 28 patients that underwent virtually planned orthognathic surgery with maxillary Le Fort I osteotomy either using VSP-generated splints (n = 13) or patient-specific implants (PSI) (n = 15) was conducted. The accuracy and surgical outcome of both techniques were compared by superimposing preoperative surgical planning with postoperative CT scans and measurement of translational and rotational deviation for each patient.ResultsThe 3D global geometric deviation between the planned position and the postoperative outcome was 0.60 mm (95%-CI 0.46–0.74, range 0.32–1.11 mm) for patients with PSI and 0.86 mm (95%-CI 0.44–1.28, range 0.09–2.60 mm) for patients with surgical splints.Postoperative differences for absolute and signed single linear deviations between planned and postoperative position were a little higher regarding the x-axis and pitch but lower regarding the y- and z-axis as well as yaw and roll for PSI compared to surgical splints.There were no significant differences regarding global geometric deviation, absolute and signed linear deviations in the x-, y-, and z-axis, and rotations (yaw, pitch, and roll) between both groups.ConclusionsRegarding accuracy for positioning of maxillary segments after Le Fort I osteotomy in orthognathic surgery patient-specific implants and surgical splints provide equivalent high accuracy.Clinical relevancePatient-specific implants for maxillary positioning and fixation facilitate the concept of splintless orthognathic surgery and can be reliably used in clinical routines.

Sensor Technology in Fracture Healing.

SMART sensor technology may provide the solution to bridge the gap between the current radiographic determination of fracture healing and clinical assessment. The displacement and rigidity between the fracture ends can be accurately measured using strain gauges. Progressively increasing stiffness is a sign of fracture consolidation which can be monitored using sensors. The design of standard orthopaedic implants can remain the same and needs no major modifications as the sensor can be mounted onto the implant without occupying much space. Data regarding various fracture morphologies and their strain levels throughout the fracture healing process may help develop AI algorithms that can subsequently be used to optimise implant design/materials. The literature search was performed in PubMed, PubMed Central, Scopus, and Web of Science databases for reviewing and evaluating the published scientific data regarding sensor technology in fracture healing. SMART sensor technology comes with a variety of uses such as determining fracture healing progress, predicting early implant failure, and determining fractures liable for non-union to exemplify a few. The main limitations are that it is still in its inception and needs extensive refinement before it becomes widely and routinely used in clinical practice. Nevertheless, with continuous advances in microprocessor technology, research designs, and additive manufacturing, the utilisation and application of SMART implants in the field of trauma and orthopaedic surgery are constantly growing. Mass production of such SMART implants will reduce overall production costs and see its use in routine clinical practice in the future and is likely to make a significant contribution in the next industrial revolution termed 'Industry 5.0' which aims at personalised patient-specific implants and devices. SMART sensor technology may, therefore, herald a new era in the field of orthopaedic trauma.

Analysis of the Effectiveness of 3D Printed Patient-Specific Implants for Reconstruction of Maxillary Defect Secondary to Mucormycosis.

Patients affected with mucormycosis of maxilla have been increasing following Covid-19 infections. We followed the reconstruction of the maxilla using 3D manufactured patient-specific implants. The additive manufacturing technology is capable of fabricating custom-made titanium implants precisely for oral and maxillofacial reconstructions. To analyse the effectiveness of 3D manufactured patient-specific implants in the reconstruction of maxilla affected by mucormycosis secondary to Covid-19. Methodology:This study was conducted among 20 patients receiving patient-specific implants for surgical and prosthetic reconstruction of the maxilla. The parameters analysed at baseline, 3months, 6months, and 12months were pain, implant exposure, infection, wound dehiscence, fit of implant, postoperative surgical rating scale, and patient experience evaluation rating scale. Inferential Statistics revealed a positive correlation. From the present data, it can be concluded that within the limitations of the study, patient-specific implant systems are an effective treatment strategy for the reconstruction of the maxilla affected by mucormycosis secondary to Covid-19. More studies with larger sample size and longer follow-up periods are required to substantiate the results from the present study. The online version contains supplementary material available at 10.1007/s12663-023-01922-7.

3D Printing Technology in Pediatric Orthopedics: a Primer for the Clinician.

This article reviews the basics of 3D printing and provides an overview of current and future applications of this emerging technology in pediatric orthopedic surgery. Both preoperative and intraoperative utilization of 3D printing technology have enhanced clinical care. Potential benefits include more accurate surgical planning, shortening of a surgical learning curve, decrease in intraoperative blood loss, less operative time, and fluoroscopic time. Furthermore, patient-specific instrumentation can be used to improve the safety and accuracy of surgical care. Patient-physician communication can also benefit from 3D printing technology. 3D printing is rapidly advancing in the field of pediatric orthopedic surgery. It has the potential to increase the value of several pediatric orthopedic procedures by enhancing safety and accuracy while saving time. Future efforts in cost reduction strategies, making patient-specific implants including biologic substitutes and scaffolds, will further increase the relevance of 3D technology in the field of pediatric orthopedic surgery.

Comparison of Two Types of Patient Specific Implants (PSI) and Quad Zygoma Implant (QZI) for Rehabilitation of Post-COVID Maxillary Mucormycosis Defect (PCMMD): Finite Element Analysis.

The residual post-COVID maxillary mucormycosis defect (PCMMD) were extensive, due to unilateral or bilateral maxillectomies. The Goal of rehabilitation of PCMMD is to deliver a prosthetically driven reconstruction. FEA was to evaluate the biomechanical response of PSI struts (PSI 1), PSI Screw retained (PSI 2) and QZI to masticatory load on virtual simulation to improve accuracy and enhance the design. To validate and compare the Biomechanical benefit of the PSI struts, PSI Screw retained, QZI in a case of rehabilitation of post-COVID maxillary mucormycosis defect (PCMMD) by FEA study. The result of stress to masticatory load on virtual simulation for (1) Maximum and minimum stress (Von Mises stress); (2) the Displacement (in three positions) and (3) the Deformation (Plastic strain) was compared on virtual simulation for PSI 1 and PSI 2 and QZI. The FEA and comparative evaluation of PSI 1, PSI 2 and QZI showed a good resistance to displacement. The stress and strain values are low and acceptable. In comparison QZI shows more stress in the anterior region.

Strength and bioactivity of PEEK composites containing multiwalled carbon nanotubes and bioactive glass

Polyetheretherketone (PEEK) polymer is a widely accepted implantable biomaterial in the biomedical field. However, PEEK has a low elastic modulus (E-modulus) as well as a bio-inert nature which is not conductive to rapid bone cell attachment, hence, producing delayed or weak bone-implant integration. Multiwalled carbon nanotubes (MWCNTs) represent one of the strongest known materials that could be added to a polymer to improve its mechanical properties. Bioactive glasses (BGs) can form hydroxyapatite deposits on their surfaces and form a tight bond with the bone, thus, their incorporation into the PEEK matrix may improve its bioactivity. MethodsEight groups were formulated according to the type and percentage of modification of PEEK by MWCNTs and BGs. Group 1: Pure PEEK (P), Group 2: P + 3% MWCNTs (PC3), Group 3: P + 5% MWCNTs (PC5), Group 4: P + 5% BGs (PG5), Group 5: P + 10% BGs (PG10), Group 6: P + 3% MWCNTs + 5% BGs (PC3G5), Group 7: P + 3% MWCNTs + 10% BGs (PC3G10), and Group 8: P + 5% MWCNTs + 5% BGs (PC5G5). Characterization of the vacuum-pressed PEEK and PEEK composite specimens was done using FE-SEM, EDS, FT-IR and TF-XRD. Three-point load test was done to obtain the flexural strength (F.S) and the E-modulus of the specimens. Wettability was determined by measuring the contact angle with distilled water. In-vitro bioactivity was determined after immersion of specimens in simulated body fluid (SBF). Moreover, the effect of the specimens on osteoblastic cell viability was evaluated. ResultsThree-point load test results have shown an improvement in both F.S. and E-modulus for groups PC5, PC3G5 and PC5G5. The lowest contact angle was obtained for group PC5G5 followed by the PC3G10 group. All specimens containing BGs showed the formation of hydroxyapatite-like deposits after their immersion in SBF, as well as an improvement in osteoblastic cell viability compared to PEEK. ConclusionPC3G10, PC3G5 and PG10, groups are promising for the fabrication of patient-specific implants that can be used in low-stress-bearing areas.

Reliable Methods for Classification, Characterization, and Design of Cellular Structures for Patient-Specific Implants.

In our research, our goal was to develop a characterization method that can be universally applied to periodic cell structures. Our work involved the accurate tuning of the stiffness properties of cellular structure components that can significantly reduce the number of revision surgeries. Up to date porous, cellular structures provide the best possible osseointegration, while stress shielding and micromovements at the bone-implant interface can be reduced by implants with elastic properties equivalent to bone tissue. Furthermore, it is possible to store a drug inside implants with a cellular structure, for which we have also prepared a viable model. In the literature, there is currently no established uniform stiffness sizing procedure for periodic cellular structures but also no uniform designation to identify the structures. A uniform marking system for cellular structures was proposed. We developed a multi-step exact stiffness design and validation methodology. The method consists of a combination of FE (Finite Element) simulations and mechanical compression tests with fine strain measurement, which are finally used to accurately set the stiffness of components. We succeeded in reducing the stiffness of test specimens designed by us to a level equivalent to that of bone (7-30 GPa), and all of this was also validated with FE simulation.

A review on 3D printing maxillofacial surgery: Present work and future prospects

The medical field is only one area that stands to benefit from the rapidly expanding capabilities of 3D printing. In the past several years, advances in technology have allowed oral and maxillofacial surgeons to provide better care for their patients. This article provides a brief summary of the present state of 3D printing in oral and maxillofacial surgery. Patient-specific implants created using computer-assisted design aid in the superior imitation of the original anatomical form. The purpose of this paper is to highlight the present applications of 3D printing in the field of maxillofacial surgery for the treatment of face deformities, aesthetic issues and jaw diseases. The medical and dental fields have seen a surge in interest in the use of additive manufacturing. Their growing use on patients has been attributed to better quality and cost effectiveness. This review simply summarized the numerous methods utilised in Bio printing, as well as their varied benefits and drawbacks. While the results of the preliminary studies have been encouraging, additional study is needed before this technology can be practical and affordable. As this technology is adopted more broadly, many more technological and regulatory hurdles will need to be cleared.