1.Research on a portable electrical impedance tomography system for evaluating blood compatibility of biomaterials.
Piao PENG ; Huaihao CHEN ; Bo CHE ; Xuan LI ; Chunjian FAN ; Lei LIU ; Teng LUO ; Linhong DENG
Journal of Biomedical Engineering 2025;42(2):219-227
The evaluation of blood compatibility of biomaterials is crucial for ensuring the clinical safety of implantable medical devices. To address the limitations of traditional testing methods in real-time monitoring and electrical property analysis, this study developed a portable electrical impedance tomography (EIT) system. The system uses a 16-electrode design, operates within a frequency range of 1 to 500 kHz, achieves a signal to noise ratio (SNR) of 69.54 dB at 50 kHz, and has a data collection speed of 20 frames per second. Experimental results show that the EIT system developed in this study is highly consistent with a microplate reader ( R 2=0.97) in detecting the hemolytic behavior of industrial-grade titanium (TA3) and titanium alloy-titanium 6 aluminum 4 vanadium (TC4) in anticoagulated bovine blood. Additionally, with the support of a multimodal image fusion Gauss-Newton one-step iterative algorithm, the system can accurately locate and monitor in real-time the dynamic changes in blood permeation and coagulation caused by TC4 in vivo. In conclusion, the EIT system developed in this study provides a new and effective method for evaluating the blood compatibility of biomaterials.
Electric Impedance
;
Animals
;
Tomography/instrumentation*
;
Biocompatible Materials
;
Materials Testing/instrumentation*
;
Cattle
;
Titanium
;
Alloys
;
Prostheses and Implants
2.Research progress on enhancing osseointegration properties of polyetheretherketone implants through various modification methods.
Shilai LIU ; Xiaoke FENG ; Chunxia CHEN
Journal of Biomedical Engineering 2025;42(2):417-422
This review article summarizes the current modification methods employed to enhance the osseointegration properties of polyetheretherketone (PEEK), a novel biomaterial. Our analysis highlights that strategies such as surface treatment, surface modification, and the incorporation of bioactive composites can markedly improve the bioactivity of PEEK surfaces, thus facilitating their effective integration with bone tissue. However, to ensure widespread application of PEEK in the medical field, particularly in oral implantology, additional experiments and long-term clinical evaluations are required. Looking ahead, future research should concentrate on developing innovative modification techniques and assessment methodologies to further optimize the performance of PEEK implant materials. The ultimate goal is to provide the clinical setting with even more reliable solutions.
Benzophenones
;
Ketones/chemistry*
;
Polyethylene Glycols/chemistry*
;
Osseointegration
;
Humans
;
Polymers
;
Biocompatible Materials/chemistry*
;
Surface Properties
;
Prostheses and Implants
;
Dental Implants
3.Clinical application standard of dynamic navigation technology in implant surgery.
Chinese Journal of Stomatology 2025;60(2):105-108
Dynamic navigation technology can "real-time guide" the implantologist to place the implant in the alveolar bone of the missing tooth area according to the preoperative design of the optimal site and path, making the whole implant surgery process more safe and precise. In order to further promote the standardized application of oral implant dynamic navigation technology, China Association of Gerontology and Geriatrics has convened distinguished experts to engage in deliberations and develop the standard. This standard covers the basic requirements, indications and contraindications, operation procedures, common complications and treatment measures, and accuracy verification. This standard can be used as a reference for the use of dynamic navigation technology in implant surgery.
Humans
;
Dental Implantation, Endosseous/standards*
;
Surgery, Computer-Assisted/standards*
;
Dental Implants
;
Surgical Navigation Systems/standards*
4.Effectiveness of three-dimensional-printed microporous titanium prostheses combined with flap implantation in treatment of large segmental infectious bone defects in limbs.
Yongqing XU ; Xinyu FAN ; Teng WANG ; Shaoquan PU ; Xingbo CAI ; Xiangwen SHI ; Wei LIN ; Xi YANG ; Jian LI ; Min LIU
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(5):521-528
OBJECTIVE:
To analyze the effectiveness of single three-dimensional (3D)-printed microporous titanium prostheses and flap combined prostheses implantation in the treatment of large segmental infectious bone defects in limbs.
METHODS:
A retrospective analysis was conducted on the clinical data of 76 patients with large segmental infectious bone defects in limbs who were treated between January 2019 and February 2024 and met the selection criteria. Among them, 51 were male and 25 were female, with an age of (47.7±9.4) years. Of the 76 patients, 51 had no soft tissue defects (single prostheses group), while 25 had associated soft tissue defects (flap combined group). The single prostheses group included 28 cases of tibial bone defects, 11 cases of femoral defects, 5 cases of humeral defects, 4 cases of radial bone defects, and 3 cases of metacarpal, or carpal bone defects, with bone defect length ranging from 3.5 to 28.0 cm. The flap combined group included 3 cases of extensive dorsum of foot soft tissue defects combined with large segmental metatarsal bone defects, 19 cases of lower leg soft tissue defects combined with large segmental tibial bone defects, and 3 cases of hand and forearm soft tissue defects combined with metacarpal, carpal, or radial bone defects, with bone defect length ranging from 3.8 to 32.0 cm and soft tissue defect areas ranging from 8 cm×5 cm to 33 cm×10 cm. In the first stage, vancomycin-loaded bone cement was used to control infection, and flap repair was performed in the flap combined group. In the second stage, 3D-printed microporous titanium prostheses were implanted. Postoperative assessments were performed to evaluate infection control and bone integration, and pain release was evaluated using the visual analogue scale (VAS) score.
RESULTS:
All patients were followed up postoperatively, with an average follow-up time of (35.2±13.4) months. In the 61 lower limb injury patients, the time of standing, walk with crutches, and fully bear weight were (2.2±0.6), (3.9±1.1), and (5.4±1.1) months, respectively. The VAS score at 1 year postoperatively was significantly lower than preoperative one ( t=-10.678, P<0.001). At 1 year postoperatively, 69 patients (90.8%) showed no complication such as infection, fracture, prosthesis displacement, or breakage, and X-ray films indicated good integration at the prosthesis-bone interface. According to the Paley scoring system for the healing of infectious bone defects, the results were excellent in 37 cases, good in 29 cases, fair in 3 cases, and poor in 7 cases. In the single prostheses group, during the follow-up, there was 1 case each of femoral prostheses fracture, femoral infection, and tibial infection, with a treatment success rate of 94.1% (48/51). In lower limb injury patients, the time of fully bear weight was (5.0±1.0) months. In the flap combined group, during the follow-up, 1 case of tibial fixation prostheses screw fracture occurred, along with 2 cases of recurrent foot infection in diabetic patients and 1 case of tibial infection. The treatment success rate was 84.0% (21/25). The time of fully bear weight in lower limb injury patients was (5.8±1.2) months. The overall infection eradication rate for all patients was 93.4% (71/76).
CONCLUSION
The use of 3D-printed microporous titanium prostheses, either alone or in combination with flaps, for the treatment of large segmental infectious bone defects in the limbs results in good effectiveness with a low incidence of complications. It is a feasible strategy for the reconstruction of infectious bone defects.
Humans
;
Male
;
Female
;
Middle Aged
;
Printing, Three-Dimensional
;
Titanium
;
Retrospective Studies
;
Surgical Flaps
;
Adult
;
Prosthesis Implantation/methods*
;
Plastic Surgery Procedures/methods*
;
Treatment Outcome
;
Prostheses and Implants
;
Bone Diseases, Infectious/surgery*
;
Extremities/surgery*
;
Prosthesis Design
5.Perioperative management of direct-to-implant-based breast reconstruction in breast cancer patients and West China Hospital experiences.
Yu FENG ; Donglin ZHANG ; Faqing LIANG ; Guilin LUO ; Zhenggui DU
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(10):1356-1362
OBJECTIVE:
To optimize the perioperative management experiences for breast cancer patients undergoing direct-to-implant-based breast reconstruction, and provide reference for clinical practice.
METHODS:
A comprehensive review of recent domestic and international literature was conducted to systematically summarize the key points of perioperative management for direct-to-implant-based breast reconstruction, including preoperative health education, intraoperative strategies, and postoperative management measures, along with an introduction to the clinical experiences of West China Hospital of Sichuan University.
RESULTS:
Standardized perioperative management can effectively reduce the incidence of complications and achieve excellent cosmetic outcomes and quality of life after operation. Preoperative management includes proactive health education to alleviate patients' anxiety and improve treatment compliance, as well as comprehensive assessment by surgeons of the patient's physical condition and reconstructive expectations to select the most appropriate implant. Intraoperative management consists of strict aseptic technique, minimizing implant exposure, preserving blood supply to the nipple-areola complex (e.g., by using minimally invasive techniques or indocyanine green angiography, etc), and meticulous hemostasis. Postoperative management encompasses multimodal analgesia, individualized drain management (such as early removal or retaining a small amount of fluid to optimize contour), infection prevention and control (including topical and systemic antibiotics, ultrasound-guided minimally invasive drainage), guidance on rehabilitation exercises (early activity restriction followed by gradual recovery), and regular follow-up to evaluate aesthetic results and monitor for complications.
CONCLUSION
Establishing a standardized, multidisciplinary perioperative management framework markedly enhances surgical safety and patient satisfaction, thereby providing a replicable benchmark for direct-to-implant-based breast reconstruction across diverse clinical settings.
Humans
;
Female
;
Breast Neoplasms/surgery*
;
China
;
Perioperative Care/methods*
;
Breast Implants
;
Mammaplasty/methods*
;
Breast Implantation/methods*
;
Postoperative Complications/prevention & control*
;
Quality of Life
;
Mastectomy
6.Effectiveness evaluation of three-dimensional printed customized hemi-pelvic prosthesis for pelvic reconstruction after resection of massive pelvic tumor.
Yuhui SU ; Chao GAO ; Huajian WU ; Zhengwang SUN ; Wangjun YAN
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(11):1414-1420
OBJECTIVE:
To investigate the effectiveness of three-dimensional (3D) printed customized hemi-pelvic prosthesis for pelvic reconstruction after resection of massive pelvic tumors.
METHODS:
A retrospective analysis was conducted on 26 patients with massive pelvic tumors who met the selection criteria and were treated between November 2021 and May 2024. The cohort included 11 males and 15 females, with a mean age of 52.65 years (range, 17-73 years). Histopathological diagnoses were as follows: 9 cases of chondrosarcoma, 2 of undifferentiated pleomorphic sarcoma, 4 of spindle cell sarcoma, 2 of osteosarcoma, 1 of solitary fibrous tumor, 1 of myxoid chondroma, 1 of malignant peripheral nerve sheath tumor, 1 of chondromyxoid epithelioma, and 5 of metastatic malignant tumors. According to the Enneking classification, tumor involvement was distributed as 4 cases in zones Ⅰ+Ⅱ, 9 in zones Ⅱ+Ⅲ, 3 in zones Ⅰ+Ⅳ, 8 in zones Ⅰ+Ⅱ+Ⅲ, and 2 in zones Ⅰ+Ⅱ+Ⅳ. The disease duration ranged from 3 to 40 months, with a mean of 9.85 months. All patients underwent reconstruction with customized 3D-printed hemi-pelvic prostheses. The effectiveness was evaluated by Musculoskeletal Tumor Society (MSTS) score and Harris hip score before operation and at last follow-up, and pain levels were evaluated by visual analogue scale (VAS) score before operation, at 3 months after operation, and at last follow-up.
RESULTS:
The operation time ranged from 186 to 528 minutes, with a mean of 334.58 minutes. The intraoperative blood loss ranged from 1 400 to 4 000 mL, with a mean of 2173.08 mL, and the transfusion volume ranged from 750 to 3 500 mL, with a mean of 1 659.62 mL. All 26 patients were followed up 10-42 months (mean, 18.5 months). Postoperative complications included prosthetic dislocation in 2 cases, which were attributed to improper positioning during home care and an accidental fall, respectively. One patient developed a vesicocutaneous fistula and poor wound healing due to pre-existing tumor invasion into the bladder. One patient experienced failure and loosening of the internal fixation at 8 months after operation caused by local tumor recurrence, and subsequently died at 14 months postoperatively due to progression of brain metastases. Postoperative complications such as poor healing of incisions, prosthetic dislocation, or failure of internal fixation was not observed in the remaining patients. At last follow-up, the walking ability of most patients recovered to varying degrees. The VAS scores at 3 months and at last follow-up significantly improved when compared with those before operation, and the scores at last follow-up further improved when compared with 3 months after operation, all showing significant differences ( P<0.05). The MSTS scores and Harris scores at last follow-up were significantly higher than those before operation ( P<0.05).
CONCLUSION
3D printed customized hemi-pelvic prosthesis is effective for reconstruction of massive pelvic tumors after resection, but there are still some limitations, and soft tissue reconstruction should be paid attention to.
Humans
;
Printing, Three-Dimensional
;
Female
;
Male
;
Adult
;
Plastic Surgery Procedures/methods*
;
Retrospective Studies
;
Middle Aged
;
Aged
;
Pelvic Bones/surgery*
;
Bone Neoplasms/surgery*
;
Adolescent
;
Pelvic Neoplasms/surgery*
;
Prosthesis Design
;
Young Adult
;
Treatment Outcome
;
Prostheses and Implants
7.Influence of emergence profile designs on the peri-implant tissue in the mandibular molar: A randomized controlled trial.
Juan WANG ; Lixin QIU ; Huajie YU
Journal of Peking University(Health Sciences) 2025;57(1):65-72
OBJECTIVE:
To compare the influence of different emergence profile of implants in mandibular molar on the peri-implant soft tissue.
METHODS:
Forty-four implants were divided into two equal groups by mucosal thickness, ≥2 mm (group A) or < 2 mm (group B), and were randomly included in the test group and the control group. In the control group, the patients were treated by a prosthesis with no transmucosal modifications (subgroups A1 and B1). In groups A1 and B1, the prostheses maintained the original emergence profile of the healing abutment. In the test group, the prostheses were designed based on a width-to-height ratio (W/H) of 1.3 ∶ 1 (subgroups A2 and B2). In group A2, the buccal transmucosal configuration design was slightly concave, and in group B2, the prostheses were designed with convex buccal transmucosal configuration. Assessments were made before delivery of the definitive restoration (T0), one month (T1) and 12 months (T2) after loading. The soft tissue and prosthesis information were obtained by intraoral scan and were converted to digital models. The digital models of different time were superimposed together. Buccal mucosal W/H, emergence angle (EA) and buccal mucosal margin recession (ΔGM) were measured.
RESULTS:
One year after loading, the buccal mucosal margin recession in the test group (groups A2 and B2) was significantly lower than that in the control group (groups A1 and B1). The ΔGM in group A2 was significantly lower than that in group A1 (P=0.033), but in groups B1 and B2, it was not significantly different. The W/H in group A2 increased significantly one month after loading, but remained stable at one year. In the A1 group, the W/H changed little from initial to one month, but increased significantly at one year after loading. The W/H in group B2 remained stable from the beginning to one year, while in group B1, it changed little one month after loading, but increased significantly by one year.
CONCLUSION
When the initial mucosal thickness was ≥2 mm, the slightly concave prosthesis designed based on the biological W/H significantly maintained the level of buccal mucosa. When the mucosal thickness was < 2 mm, the slightly convex prosthesis design maintained a more stable W/H over one year.
Humans
;
Mandible/surgery*
;
Molar/surgery*
;
Male
;
Female
;
Adult
;
Middle Aged
;
Dental Prosthesis Design
;
Dental Implants
;
Dental Implantation, Endosseous/methods*
8.One-stage mandibular reconstruction combining iliac flap with immediate implant-based denture.
Yifan KANG ; Yanjun GE ; Xiaoming LV ; Shang XIE ; Xiaofeng SHAN ; Zhigang CAI
Journal of Peking University(Health Sciences) 2025;57(1):78-84
OBJECTIVE:
To evaluate the clinical outcomes and define the indications for a one-stage mandibular reconstruction technique that combines iliac bone flaps with immediate implant-based dentures, and to assess both the accuracy of surgical planning and the long-term success of the procedure.
METHODS:
A total of ten patients underwent the procedure at Peking University Hospital of Stomatology between June 2020 and August 2023. The preoperative biopsy pathology of all the patients confirmed a benign tumor. In this technique, iliac bone flaps were used for mandibular reconstruction, and immediate implant-based dentures were placed during the same surgical session. Various outcome measures were evaluated, including the accuracy of the surgical reconstruction, implant placement deviations (entry point, apical point, depth, and angle), and long-term outcomes, such as cervical bone resorption, implant survival, and the cumulative survival rate.
RESULTS:
Thirty-eight implants were successfully inserted into the iliac flaps of the ten patients. The median follow-up duration was 23.5 months, and no significant complications occurred during the follow-up period, such as infections, titanium plate exposure, implant loosening, or damage to the implants and dentures. The accuracy of preoperative virtual surgical planning (VSP) was highly reliable. The repeatability of the VSP model compared to the postoperative reconstructed mandible was as follows: 67.82% ±10.16% within 1 mm, 82.14% ±6.58% within 2 mm, and 90.61% ±4.62% within 3 mm. The average maximum deviation from the plan was (6.10±0.89) mm, with an average overall deviation of (1.14±0.31) mm. For the implants, deviations in critical parameters were as follows: entry point deviation was (2.02±0.58) mm, apical point deviation was (2.25± 0.66) mm, depth deviation was (1.26±0.51) mm, and angular deviation was 1.84°±1.10°. The implant survival rate remained 100% during the follow-up, with a cumulative survival rate of 97.37% from 1 to 4 years. Average cervical bone resorption was 0.94 mm.
CONCLUSION
The combination of iliac bone flaps with immediate implant-based dentures for one-stage mandibular reconstruction demonstrated pro-mising clinical outcomes, including high implant survival and minimal complications. This technique proved to be safe and reliable for mandibular reconstruction. However, further studies with larger sample sizes and longer follow-up periods are necessary to confirm the long-term efficacy and optimal indications for this procedure.
Humans
;
Mandibular Reconstruction/methods*
;
Male
;
Ilium/surgery*
;
Female
;
Middle Aged
;
Surgical Flaps
;
Adult
;
Mandible/surgery*
;
Aged
;
Dental Implantation, Endosseous/methods*
;
Immediate Dental Implant Loading/methods*
;
Bone Transplantation/methods*
;
Dental Implants
9.Accuracy of dynamic navigation system for immediate dental implant placement.
Hong LI ; Feifei MA ; Jinlong WENG ; Yang DU ; Binzhang WU ; Feng SUN
Journal of Peking University(Health Sciences) 2025;57(1):85-90
OBJECTIVE:
Dynamic navigation approaches are widely employed in the context of implant placement surgery. Implant surgery can be divided into immediate and delayed surgery according to the time of implantation. This retrospective study was developed to compare the accuracy of dynamic navigation system for immediate and delayed implantations.
METHODS:
In the study, medical records from all patients that had undergone implant surgery between August 2019 and June 2021 in the First Clinical Division of the Peking University School and Hospital of Stomatology were retrospectively reviewed. There were 97 patients [53 males and 44 females, average age (47.14±11.99) years] and 97 implants (delayed group: 51; immediate group: 46) that met with study inclusion criteria and were included. Implant placement accuracy was measured by the superposition of the planned implant position in the preoperative cone beam computed tomography (CBCT) image and the actual implant position in the postoperative CBCT image. The 3-dimensional (3D) entry deviation (3D deviation in the coronal aspect of the alveolar ridge), 3D apex deviation (3D deviation in the apical area of the implant) and angular deviation were analyzed as the main observation index when comparing these two groups. The 2-dimensional (2D) horizontal deviation of the entry point and apex point, and the deviation of entry point depth and apex point depth were the secondary observation index.
RESULTS:
The overall implant restoration survival rate was 100%, and no mechanical or biological complications were reported. The implantation success rate was 100%. The 3D entry deviation, 3D apex deviation and angular deviation of all analyzed implants were (1.146±0.458) mm, (1.276±0.526) mm, 3.022°±1.566°, respectively; while in the delayed group these respective values were (1.157±0.478) mm, (1.285±0.481) mm and 2.936°±1.470° as compared with (1.134±0.440) mm, (1.265±0.780) mm, 3.117°±1.677° in the immediate group. No significant differences (P=0.809, P=0.850, P=0.575) in accuracy were observed when comparing these two groups.
CONCLUSION
Dynamic computer-assisted implant surgery system promotes accurate implantation, and both the immediate and delayed implantations exhibit similar levels of accuracy under dynamic navigation system that meets the clinical demands. Dynamic navigation system is feasible for immediate implantation.
Humans
;
Male
;
Female
;
Retrospective Studies
;
Middle Aged
;
Cone-Beam Computed Tomography
;
Dental Implantation, Endosseous/methods*
;
Surgery, Computer-Assisted/methods*
;
Dental Implants
;
Adult
;
Surgical Navigation Systems
;
Immediate Dental Implant Loading/methods*
;
Imaging, Three-Dimensional
10.Application of dual chamber round tissue expander in immediate breast reconstruction.
Jianxun MA ; Xi BU ; Bi LI
Journal of Peking University(Health Sciences) 2025;57(1):166-171
OBJECTIVE:
To explore the application value of dual chamber round tissue expander in immediate breast reconstruction.
METHODS:
Sixteen patients, who had been provided immediate tissue expander/implant two-stage breast reconstruction using dual chamber round tissue expander in our hospital from March 2022 to October 2023, were involved in this study, and the relevant information was analyzed retrospectively. The overall design of the expander is a round shape, consisting of two equally divided semi-circular chambers. The two expansion chambers are connected by a silicone pad below and are respectively connected to their own water injection tubes. Both chambers are designed to expand unidirectionally towards the surface. The expansion principle, insertion process, and type of expander selection were investigated. The expansion effect and incidence of complications were summarized. The aesthetic effect of reconstructed breasts was evaluated from three aspects after stage Ⅱ surgery: the position of infra mammary fold, the breast protrusion, and the breast volume.
RESULTS:
Among sixteen patients in this study, three patients were selected with the type of 400 mL expander and thirteen patients were given the type of 600 mL expander. The median time of tissue expansion was 4.0 (2.0, 5.0) months, with an average volume of expansion of (538.8±111.7) mL. The average expansion ratio of upper/lower chamber was 45.4%±8.4%. The position of the infra mammary fold needed not to be adjusted during the prosthesis exchange process. All the patients were applied anatomical prostheses, and the median volume of the prosthesis was 395 (345, 410) mL. One patient developed seroma during expansion period, who got improved after local aspiration. The average follow-up time was (9.0±3.6) months. 81.3% (13/16) of the patients achieved an aesthetic evaluation of "Good" in breast reconstruction, and 75.0% (12/16) of the patients got a grade Ⅰ or grade Ⅱ capsule contracture of the prosthesis.
CONCLUSION
The application of dual chamber round tissue expander could effectively dilate the lower pole of the breast, personalize the expansion ratio of the upper and lower poles of the breast, and avoid the displacement of the expander during the expansion period. Therefore, it could provide a good foundation for subsequent prosthesis exchange.
Humans
;
Tissue Expansion Devices
;
Female
;
Mammaplasty/instrumentation*
;
Tissue Expansion/instrumentation*
;
Retrospective Studies
;
Adult
;
Middle Aged
;
Breast Neoplasms/surgery*
;
Breast Implants
;
Mastectomy

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