Regulatory effects of micro-arc oxidation on anti-bacterial and anti-inflammatory properties of metal implants / 中国组织工程研究

BACKGROUND:Micro-arc oxidation can effectively add bioactive elements to the metal surface and improve the anti-bacterial and anti-inflammatory properties of biomedical metal materials,so this technology has become one of the hotspots of biomedical materials. OBJECTIVE:To summarize the anti-bacterial and anti-inflammatory properties of surface coatings prepared by the combination of micro-arc oxidation and other surface modification technologies. METHODS:Articles from January 1996 to December 2022 were searched on CNKI,WanFang and PubMed databases using Chinese and English search terms"micro-arc oxidation,antibacterial properties,anti-inflammatory properties,metal implants".After preliminary screening according to inclusion and exclusion criteria,89 articles were retained and summarized. RESULTS AND CONCLUSION:The ceramic layer prepared by micro-arc oxidation can improve the anti-bacterial and anti-inflammatory properties of titanium,magnesium and other alloys.Combination with other surface modification technologies can effectively solve the effect of pores on the surface properties of the alloy,and further improve the biological properties of the oxide film.It has a wide application prospect in orthopedics and dentistry.At present,most studies are limited to metal coatings,and most of them focus on metal elements with good antibacterial properties such as silver and copper,while only a few studies mention non-metallic coatings such as graphene oxide,hydroxyapatite and chitosan.In the future,extensive studies can be conducted on inorganic coatings and polymer coatings,and more combinations of different bioactive elements can also be adopted to improve antibacterial properties.Currently,studies on the inflammation of implant coatings prepared by micro-arc oxidation are mostly limited to the immune system and focused on macrophages,while studies on neutrophils and platelets are scarce.In the future,a variety of advanced technologies should be combined to explore the specific effects of micro-arc oxidation coating on other immune cells and inflammatory cells.

A preliminary study on the relationship between in vivo metal implants and acquired palmoplantar keratodermas / 中华皮肤科杂志

Objective:To investigate clinical characteristics of acquired palmoplantar keratodermas (PPK) and the effect of metal implants (MIs) on plasma cytokines in patients with PPK.Methods:An observational study was conducted. Patients with acquired PPK were collected from Department of Dermatology, General Hospital of Eastern Theater Command from June 2020 to December 2021, and health checkup examinees during the same period served as controls. The PPK area and severity index was evaluated according to the eczema area and severity index, metal allergens were detected by metal patch test (MPT) , and plasma levels of cytokines, including tumor necrosis factor (TNF) -α, interferon (IFN) -γ, interleukin (IL) -4, IL-13, IL-17A and IL-8, were detected by enzyme-linked immunosorbent assay. Non-normally distributed measurement data were expressed as median (quartile 1, quartile 3) , and analyzed by rank sum test; intergroup comparisons of enumeration data were performed by chi-square test.Results:A total of 81 PPK patients were collected, including 42 males and 39 females, and their average age was 48 years (range, 21 - 65 years) . In vivo MIs were found in 37 (45.7%) patients, including dental implants in 34, orthopedic implants in 2, and cardiac implants in 1. During the same period, 36 healthy subjects were included in the control group, and there was no significant difference in the age and gender composition between the two groups ( P > 0.05) . No significant difference was observed in the PPK area and severity index between the MI group (37 cases, 0.40 [0.27, 0.75] points) and non-MI group (44 cases, 0.38 [0.19, 0.70] points; Z = 1.21, P = 0.225) . Forty-six patients in the PPK patient group and 30 in the control group were subjected to MPT, and the positive rate of MPT was significantly higher in the patient group (14/46) than in the control group (2/30, χ2 = 6.17, P = 0.013) , and was significantly higher in the patients with in vivo MIs (10/25) than in the patients without (4/21, adjusted P < 0.017) . Plasma cytokines were detected in 36 cases in the patient group and 36 in the control group. The plasma levels of TNF-α and IFN-γ were significantly lower in the patient group (66.2 [58.7, 69.3] pg/ml, 645.0 [571.5, 681.1] pg/ml, respectively) than in the control group (71.5 [64.5, 73.9] pg/ml, 716.5 [620.4, 785.0] pg/ml, respectively; both P < 0.05) , but there was no significant difference in the levels of plasma IL-4, IL-13, IL-17A and IL-8 between the two groups (all P > 0.05) . Conclusions:Positive MPT reaction is more common in acquired PPK patients, especially in patients with in vivo MIs. There may be a correlation between metal and acquired PPK, and changes in plasma TNF-α and IFN-γ levels may be related to the onset of some acquired PPK.

A Case of Intralymphatic Histiocytosis after Orthopedic Metal Implants / 대한피부과학회지

A 64-year-old female presented with a 1-year history of livedo-like erythematous patches and plaques around the surgical scar on the left knee. Examinations revealed poorly demarcated, erythematous, indurated patches and plaques, with mild tenderness overlying the medial and inferior portion of the surgical scar. Histopathology revealed a mixed dermal infiltrate with glomeruloid intravascular accumulation of histiocytes and neutrophils. Histiocytes were identified by immunostaining for CD68. Immunostains for CD31 and D2-40 confirmed the intra-lymphatic location of the histiocytes. Recently, there have been several case reports of erythematous patches around the joints, which histopathologically show histiocytic aggregations in dermal vessels. Intra-lymphatic histiocytosis is a rare group of skin diseases characterized by the proliferation of histiocytes in the vessel lumen. Although the pathogenesis of intra-lymphatic histiocytosis is unknown, a role for lymphatic stasis secondary to chronic inflammation or surgery has been suggested. We present the case of a 64-year-old female who developed a tender rash on her left knee 1 year after orthopedic metal implants. To our knowledge, this is the first case of intra-lymphatic histiocytosis reported in association with a metal implant in the Korean dermatologic literature.

Flexural strength of implant fixed prosthesis using fiber reinforced composite / 대한치과보철학회지

STATEMENT OF PROBLEM: Use of fiber composite technology as well as development of nonmetal implant prosthesis solved many problems due to metal alloy substructure such as corrosion, toxicity, difficult casting, expensiveness and esthetic limit. After clinical and laboratory test, we could find out that fiber-reinforced composite prostheses have good mechanical properties and FRC can make metal-free implant prostheses successful. PURPOSE: The purpose of this study is to evaluate the flexural strength of implant fixed prosthesis using fiber reinforced composite. MATERIAL AND METHODS: 2-implant fixture were placed in second premolar and second molar area in edentulous mandibular model, and their abutments were placed, and bridge prostheses using gold, PFG, Tescera, and Targis Vectris were fabricated. Tescera was made in 5 different designs with different supplements. Group I was composed by 3 bars with diameter 1.0mm and 5 meshes, 2 bars and 5 meshes for Group II, 1 bar and 5 meshes for Group III, and only 5 meshes were used for Group IV. And Group V is composed by only 3 bars. Resin (Tescera) facing was made to buccal part of pontic of gold bridge. All of gold and PFG bridges were made on one model, 5 Targis Vectris bridges were also made on one model, and 25 Tescera bridges were made on 3 models. Each bridge was attached to the test model by temporary cement and shallow depression was formed near central fossa of the bridge pontic to let 5 mm metal ball not move. Flexual strength was marked in graph by INSTRON. RESULTS: The results of the study are as follows. The initial crack strength was the highest on PFG, and in order of gold bridge, Tescera I, Tescera II, Targis vectris, Tescera IV, Tescera III, and Tescera V. The maximum strength was the highest on gold bridge, and in order of PFG, Tescera I, Tescera IV, Tescera II, Targis vectris, Tescera III, and Tescera V. CONCLUSIONS: The following conclusions were drawn from the results of this study. 1. Flextural strength of implant prosthesis using fiber reinforced composite was higher than average posterior occlusal force. 2. In initial crack strength, Tescera I was stronger than Tescera V, and weaker than PFG. 3. Kinds and number of auxillary components had an effect on maximum strength, and maximum strength was increased as number of auxillary components increased. 4. Maximum strength of Tescera I was higher than Targis vectris, and lower than PFG.

Rapid prototyping and individualized metal implant in clinical orthopedics / 中国矫形外科杂志

The ideal treatment of osteonosus and bone tumor is individualized treatment with individualized implants on the basis of patient's geometrical anatomic condition.Traditional metal implants are lack of individual matching.The new individualized metal implant is based on reverse engineering and rapid prototyping technique,and has solved the problems of long period manufactural procedure in the traditional technique.New type of material is applied for rapid prototyping directly.It would be the developing tendency in orthopedic application.