A comprehensive study on the risk factors and pathogen analysis of postoperative wound infections following caesarean section procedures.

Postoperative wound infections (PWIs), a subtype of surgical site infections, are a significant concern for patients undergoing caesarean sections (C-sections). Understanding risk factors and pathogen profiles can greatly assist in early diagnosis and effective treatment. This study aimed to identify risk factors and analyse the pathogenic landscape contributing to PWIs in C-sections. A nested case-control study was carried out, utilising stringent criteria for case selection and control matching. Diagnostic criteria for surgical site infections included both clinical and microbiological parameters. Risk variables examined included patient age, Body Mass Index, duration of surgery and several other clinical indicators. Microbiological analysis was performed using the BD Phoenix-100 Automated Bacterial Identification System. Statistical analyses were conducted using SPSS version 26.0, and risk factors were evaluated through both univariate and multivariate analyses. A total of 50 patients, aged between 20 and 45 years (mean age 26.3 ± 5.6), developed PWIs following C-sections. The study revealed a temporal distribution and various clinical indicators of PWIs, including elevated white blood cell count and C-reactive protein levels. Gram-negative bacteria were found to be more prevalent at 57.4%. Notable pathogens included Pseudomonas aeruginosa and Acinetobacter baumannii. Antimicrobial resistance patterns were also identified, highlighting the need for a targeted antibiotic approach. Increased infection risks were linked to lack of prophylactic antibiotics, absence of preoperative povidone-iodine antisepsis, operations over an hour, anaemia, amniotic fluid contamination, diabetes, GTI, premature rupture of membranes and white blood cells counts above 10 × 109 /L. The study provides critical insights into the risk factors and microbial agents contributing to PWIs following C-sections. Our findings emphasise the importance of early diagnosis through clinical and laboratory parameters, as well as the need for constant surveillance and reassessment of antibiotic stewardship programs.

Reversible Chemical Protein Modification to Endogenous Glutathione and Its Utilities in the Manufacture of Transcellular Pro-Enzymes.

Proteins have been perceived as being an intriguing modality of therapeutics for the treatment of intractable diseases in view of their superlative precision and versatility. Nonetheless, proteins' intrinsic characters, particularly their being hydrophilic macromolecules with unmethodical charges, have imposed the exceeding challenge of seeking transcellular trafficking into cells' interiors. To circumvent this drawback, we have attempted to employ triple-functional amine-reactive 4-(2-((2-(((4-nitrophenoxy)carbonyl)oxy)ethyl)disulfaneyl)ethoxy)-4-oxobutanoic acid for the efficient incorporation of the anionic carboxyl moiety into amine-enriched enzymes, resulting in overall negatively charged pro-enzymes. The resulting pro-enzymes could be readily electrostatically assembled with cationic species [for instance: block copolymers of poly(ethylene glycol)-polylysine] into core-shell architectural delivery nanoparticles for their facilitated endocytosis into cells. Noteworthy is the aforementioned carboxylation chemistry designed to allow facile reversal of the pro-enzymes to the original amine groups due to the thiolysis of intermediate disulfide linkage for subsequent cascade reactions in response to the cytosol-enriched glutathione. Therefore, cytosol-selective structural disassembly for the liberation and activation of the pro-enzymes was accomplished. Our subsequent investigations utilizing ribonuclease A and catalase as the model enzymes demonstrated appreciable transcellular transportation of the active enzymes to the cell interiors, exerting overwhelming cytotoxic potencies and H2O2 scavenging capacities, respectively. Hence, we reported an unprecedented redox-stimulated charge reversal strategy in engineering cytosol-activatable pro-enzymes, manifesting a simple and efficient approach in the manufacture of transcellular proteinic therapeutics, which should be highlighted to promote their wide availability for use with diverse functional proteins as molecular biological tools and precision therapeutics.

Electrochemical characteristics of microelectrode designed for electrical stimulation.

BACKGROUND: Microelectrode arrays play an important role in prosthetic implants for neural signal recording or applying electrical pulses stimulation to target nerve system. Safety and long-term reliability are essential requirements for microelectrode arrays applied in electrical stimulation. In design and fabrication of the microelectrode array, soft materials are generally chosen to be the substrate for the aim of achieving better compliance with the surrounding tissue while maintaining minimal damage. By flexing of the array to the surface, the array is capable of keeping a more stable electrical contact resulting in a significantly improved signal detected. METHODS: In this study, we design and fabricate a flexible microelectrode array with gold as the electrode material and parylene-C as the substrate. The fabrication process of the array is presented. The in vitro electrochemical characteristics of the microelectrode are investigated by electrochemical impedance spectroscopy and cyclic voltammetry in a three-electrode electrochemical cell containing phosphate-buffered saline. Charge injection capacity measurements are carried out by multichannel systems and the CSC of the microarray is calculated. RESULTS: Electrochemical results showed that impedance decreased with frequency. The average impedance of the Au electrodes at 1 kHz was 36.54 ± 0.88 kΩ. The average phase angle at 1 kHz was - 73.52 ± 1.3°, and the CIC of the microelectrode was 22.3 µC/cm2. The results demonstrated that the microelectrode array performed as expected for neuronal signal recording or stimulation. CONCLUSIONS: With parylene-C as the substrate, the microarray has good flexibility. The electrochemical characteristics' results show that the array has the ability to resist any corrosion on metal-electrolyte interface and has good biocompatibility. This low-cost, flexible parylene-based, gold microelectrode array shows potential for use in implant neurological signal acquisition or neurostimulation applications.

Simultaneous and sensitive detection of dual DNA targets via quantum dot-assembled amplification labels.

We describe a signal amplification assay for the simultaneous detection of HIV-1 and HIV-2 via a quantum dot (QD) layer-by-layer assembled polystyrene microsphere (PS) composite in a homogeneous format. The crucial point of this composite is the core-shell system. PS is utilized as the core and QDs as the shell. Based on the high affinity of streptavidin and biotin, QDs are assembled layer-by-layer on the surface of the PS as amplification labels. Biotinylated reporter probe is combined with the PS-QDs conjugate and then hybridized with target DNA immobilized on the surface of a 96-well plate. Using this approach, each target DNA corresponds to a large number of QDs and the fluorescence signal is greatly enhanced. Two QD colors (605 and 655 nm) are used to detect dual-target DNAs simultaneously. Taking advantage of the enzyme-free reaction and high sensitivity, this PS-QD-based sensor can be used in simple 'mix and detection' assays. Our results show that this technology has potential application in rapid point-of-care testing, gene expression studies, high-throughput screening and clinical diagnostics.

[Clinical evaluation of "All-on-Four" provisional prostheses reinforced with carbon fibers].

OBJECTIVE: To assess the clinical effects of carbon fiber reinforcement on the "All-on-Four" provisional prostheses. METHODS: Provisional prostheses were divided into control group and carbon fiber reinforcing group according to whether carbon fiber reinforcement was used in the provisional prostheses base resin. In our study, a total of 60 patients (32 males and 28 females) with 71 provisional prostheses(28 maxilla and 43 mandible)were enrolled between April 2008 and December 2012 for control group; a total of 23 patients (13 males and 10 females) with 28 provisional prostheses (9 maxillas and 19 mandibles) were enrolled between January 2013 and March 2014 for carbon fiber reinforcing group. The information of provisional prostheses in the patients was recorded according to preoperative examination. We used the date of definitive prosthesis restoration as the cut-off point, observing whether fracture occurred on the provisional prostheses in the two groups. Additionally we observed whether fiber exposure occurred on the tissue surface of the provisional prostheses and caused mucosal irritation. The interface between the denture base resin and the fibers was examined using scanning electron microscopy (SEM). RESULTS: The age [(57.3 ± 10.1) years vs.(55.1 ± 11.4) years], gender (32 males and 28 females vs. 13 males and 10 females), maxilla and mandible distributions (28 maxillas and 43 mandibles vs. 9 maxillas and 19 mandibles), the number of extraction jaws (46 vs. 23), the average using time [(7.8 ± 1.3) months vs. (7.5 ± 1.1) months], and the opposing dentition distributions of provisional prostheses of the patients showed no significant differences between the control and reinforcing groups. There were 21(29.6%) fractures that occurred on the 71 provisional prostheses in the control group; there was no fracture that occurred on the 28 provisional prosthesesin the carbon fiber reinforcing group. The fracture rate of the carbon fiber reinforcing group was significantly lower than that of the control group (P=0.001). No carbon fiber exposure and mucosal irritation were observed from clinical examination.SEM revealed relatively continuous contact between the fiber and acrylic resin, and the resin particles adhered on the surface of the carbon fibers. CONCLUSION: The addition of carbon fibers between abutments placed on "All-on-Four" provisional fixed denture base resin may be clinically effective in preventing "All-on-Four" denture fracture and can provide several advantages for clinical use.

[Implanting the edentulous jaws with "All-on-4" immediate reconstruction: a preliminary clinical observation].

OBJECTIVE: To evaluate the treatment outcome of the "All-on-4" immediate loading protocol via survival rate of the implants,survival rate of the prosthesis,marginal bone, postoperative complications and patient satisfaction. METHODS: In our study, 40 patients with 49 edentulous jaws (31 mandibles and 18 maxillae) were enrolled. Each jaw was restored by the shortened dental arch prosthesis supported by only 4 implants according to the All-on-4 protocol (All-on-4, Nobel Biocare AB, Goteborg, Sweden). For all the patients enrolled in the study, the loading was applied within 12 hours of surgery. The provisional prosthesis could be replaced by the final restorations within 6 to 12 months. In the present study, the survival rate of the both implants and restorations were calculated and analyzed. The radiographic evaluation of marginal bone level changes was measured. The values of the marginal bone level changes of the angled and axial implants were analyzed by the statistic software. RESULTS: In the present study, totally 196 implants were inserted, of which 13 implants failed during the whole following up periods, with 11 implants of the maxillae and 2 of the mandibles. The survival rate of the prosthesis was 95.9% (47/49). The implant survival rate of the maxillae was 85.5% (65/76)while that for the mandibles was 98.3%(118/120). The implant survival rate of the angled implants was 91.8% (90/98), while that for the straight implants was 95.0% (93/98). No significant difference in marginal bone loss was found between angled and axial implants in the 12-month evaluation according to the Wilcoxon rank sum test (P>0.05). During the follow-up period,mechanical complications as fracture of the provisional prostheses, loose of the retain screw, or crack of the artificial teeth were found in 20 prostheses. CONCLUSION: The present preliminary data of the short term observation suggest that the "All-on-4" immediate loading protocol is a viable treatment modality for the edentulous jaws. However, long term clinical random controlled trials with large samples are still needed to confirm the validity of the technique.

Synthetic genomic nanomedicine with triple-responsiveness for systemic anti-tumor therapy.

To overcome the biological barriers in the journey of systemic gene delivery, a multifaceted genomic synthetic nanomedicine was elaborated and strategically equipped with a multiple of intriguing responsiveness. Particularly, core-shell plasmid DNA condensates were created based on polyionic complexation with block copolymer of polyethylene glycol (PEG)-polylysine (PLys), namely, the nanoscaled PLys&pDNA nanoparticle tethered with the biocompatible PEG surroundings. Furthermore, redox-reversible disulfide crosslinking was introduced into PLys&pDNA nanoparticle to accomplish adequate structural stabilities, and thermal-responsive polypropylacrylamide (PNIPAM) was introduced as the secondary intermediate surroundings onto the pre-formulated PLys&pDNA nanoparticle with the aim of preventing the potential enzymatic degradation from the environmental nucleases. Hence, hundreds of times prolonged survival and retention was determined in pertinent to the blood circulation properties. Additionally, the installation of a guide ligand at the distal end of PEG segments was proposed to encourage selective tumor uptake. A linear peptide of GPLGVRG, which is selectively susceptible to digestion by the tumor-enriched matrix metalloproteinase 2 (MMP-2), was used as the linkage between the shell and core. This peptide has been shown to detach the bio-inert PEGylation, resulting in further facilitated cell endocytosis and intracellular trafficking activities. Hence, the precisely defined synthetic nanomedicine, which exhibits desirable characteristics, efficient expression of the therapeutic gene in the affected cells, and contributed to potent therapeutic efficacy in systemic treatment of intractable tumors by encapsulating the anti-angiogenic gene.

Triple-transformable dynamic surroundings for programmed transportation of bio-vulnerable mRNA payloads towards systemic treatment of intractable solid tumors.

The surface physiochemical properties of nanomedicine play a crucial role in modulating biointerfacial reactions in sequential biological compartments, accordingly accomplishing the desired programmed delivery scenario to intracellular targets. PEGylation, which involves modifying the surface with a layer of poly(ethylene glycol), has been validated as an effective strategy for minimizing adverse biointerfacial interactions. However, it has also been observed to impede cellular uptake and intracellular trafficking activities. To address this dilemma, we propose a dynamic surface chemistry approach that actively prevents non-specific reactions in systemic circulation, while readily facilitating cellular uptake by converting into a highly cytomembrane-adhesive state. Moreover, the surface becomes more adhesive to endolysosomal membranes, enabling translocation into the cytosol. In this study, PEGylated mRNA delivery nanoparticulates were tethered with charge-reversible polymers to create dynamic surroundings through click chemistry. Importantly, the dynamic surroundings exhibited negative charges under physiological conditions (pH 7.4). This property prevented degradation by anionic nucleases and structural disassembly induced by endogenous charged biological species. Consequently, the nanoparticles exhibited appreciable stealth function, effectively managing the first pass effect, leading to prolonged blood retention and improved bioavailabilities at targeted cells. Furthermore, the dynamic surroundings shifted towards relatively positive charges in the tumor microenvironment (pH 6.8). As a result, the nanoparticles were more likely to be taken up by tumors due to their electrostatic affinities towards polyanionic cytomembranes. Eventually, the internalized mRNA nanomedicine transformed responsive to the surrounding microenvironment into highly positive charges within acidic endolysosomes (pH 5.0), exerting explosive disruptive potencies on the endolysosomal structures, thus facilitating translocation of mRNA from the digestive endolysosomes into the targeted cytosol. Notably, the dynamic surroundings also reduced the immunogenicity of naked mRNA due to their stealthy properties and rapid endolysosomal translocation functions. In summary, our proposed unique triple-transformable dynamic surface chemistry provided an intriguing delivery scenario that overcomes sequential biological barriers, contributing to efficient expression of the encapsulated mRNA at targeted tumors.

pH-responsive organic/inorganic hybrid nanocolloids for transcellular delivery of ribonucleolytic payloads toward targeted anti-glioma therapy.

Proteins have been appreciated to be a superlative modality of therapeutics in view of their direct roles in regulating diverse sets of biological events, nonetheless, the clinical applications of the proteinic therapeutics have been strictly limited to act on the cell surface receptors owing to their inherent cell-impermeable character of the proteins. To this obstacle, we contrived carboxylation reaction upon the proteins (RNase A) into the overall negatively charged pro-RNase, followed by elaboration of intelligent pH-responsive pro-RNase delivery nanocolloids based on co-precipitation of pro-RNase and Arg-Gly-Asp (RGD)-functionalized poly(ethylene glycol) (PEG)-block-polyanion with aids of inorganic calcium phosphate (CaP). The resulting nanocolloids appeared to actively accumulate into glioma due to the specific binding affinities of RGD and glioma-enriched αVß3 and αVß5 integrins. Furthermore, the pH responsiveness to the acidic endolysosomal microenvironment of all compositions of nanocolloids (including: decarboxylation of pro-RNase composition to restore the native RNase A, ionization of CaP composition to elicit osmotic pressure, and charge reversal of PEG-block-polyanion into membrane-disruptive polycation) could stimulate not only efficient endolysosomal escape for translocation into the cytosol but also structural disassembly for ready liberation of the RNase A payloads, eventually exerting non-specific RNA degradation for apoptosis of the affected cells. Systemic dosage of the proposed nanocolloids demonstrated potent anti-tumor efficacies towards xenograft glioma due to massive RNA degradation. Therefore, our proposed RNase A prodrug nanocolloids could represent as a versatile platform for engineering transcellular protein delivery systems, which are expected to spur thriving emergence of a spectrum of proteins in precision intervention of intractable diseases.

[Effect of provisional restoration on shaping the contour of the soft tissue during maxillary single tooth implant procedure].

OBJECTIVE: To evaluate the influence of soft tissue aesthetic outcomes following application of adhensive fixed partial denture and implant supported temporary restoration in maxillary single tooth implant procedure. Discuss the feasibility and details of the shaping the soft tissue by combine adhensive fixed partial denture and implant-supported temporary restoration. METHODS: The study included 29 patients(Male: 17, Female: 12) with hopeless maxillary single tooth from Sept. 2008 to Dec. 2010. All patients received tooth extraction and implant treatment in department of oral implantology, Peking University School and hospital of Stomatology. The adhesive fixed partial denture as a provisional restoration was used to support the soft tissue of the tooth extraction socket after tooth extraction. The average time of patient wearing adhensive fixed partial denture was 3.7 months. The implant supported temporary restoration was delivered to shape the soft tissue after implant placement. The average time of implant supported provisional restoration using was 8.3 months. Soft tissue esthetic condition was evaluated through 4 main index reference pink esthetic score (PES) before tooth extraction and at the time of the final restoration. Clinical observe items also included the survival rate of fixed partial denture and rate of re-adhesive, integrity of temporary restoration and degree of satisfaction of the patients. The control group included 29 cases with removable denture or without temporary restoration. The base line differences between control group and experiment group were not statistically significant. RESULTS: The survival rate of both the adhensive partial denture and implant-supported provisional restoration was 100%. The re-adhesive rate of adhesive partial denture was 16.2% during follow-up period. The PES at the time of final restoration were significant different between two groups by t test (7.48±0.51 vs. 5.69±0.71, P<0.000 1). Patients were satisfied with the clinical results. CONCLUSION: This study indicates that fixed partial restoration and implant-supported provisional restoration could be used to support and to shape the soft tissue contour and to improve the aesthetic effects.

Charge-Reversible Pro-Ribonuclease Enveloped in Virus-like Synthetic Nanocapsules for Systemic Treatment of Intractable Glioma.

We have tailored multifaceted chemistries into the manufacture of artificial virus-like delivery vehicles mimicking viral "intelligent" transportation pathways through sequential biological barriers; these vehicles can acquire the ability to dynamically "program transfer" to their target sites. To accomplish this, we created anionic pro-proteins, which facilitate charge reversal when subject to acidic endosomal pH; in this way, carboxylation reactions are performed on proteins with amine-reactive cis-aconitic anhydride. Electrostatic associations then initiate the envelopment of these pro-proteins into multilayered nanoarchitectural vehicles composed of multiple-segmental block copolycationic cyclic Arg-Gly-Asp (RGD)-poly(ethylene glycol)(PEG)-GPLGVRG-polylysine(thiol). Therefore, upon the pro-proteins' initial binding to the tumors via the protruding RGD ligands, the bio-inert PEG surroundings are detached through the enzymolysis of the intermediate GPLGVRG linkage by tumor-enriched matrix metalloproteinases, unveiling the cationic polylysine palisade and imparting intimate affinities to the anionic cytomembranes of the targeted tumors. Essentially, through their active endocytosis into the subcellular endosomal compartments, the pro-proteins are made capable of retrieving the original amine groups through a charge reversal decarboxylation process, consequently eliciting augmented charge densities (charge nonstoichiometric protein@polylysine(disulfide)) to disrupt the anionic endosomal membranes to facilitate translocation into the cytosol. Eventually, the active protein payloads can be liberated from nonstoichiometric protein@polylysine(thiol) by the disassembly of polylysine palisade upon the cleavage of disulfide crosslinking in response to the very high level of glutathione in the cytosol, thereby contributing toward extreme cytotoxic potency. Hence, our elaborated virus-mimicking platform has demonstrated potent antitumor efficacy through the systemic administration of ribonucleases, which will consequently lead to an innovative new therapeutic method by which proteins could reach intracellular targets.

Camptothecin Nanoprodrug Possessing Dual Responsiveness to Endolysosomal pH and Cytosolic Redox for Amplified Cytotoxic Potency.

Selective activation of prodrug nanomedicine in cell interiors is deemed to be crucial in pursuit of precision anti-tumor therapy. In the present study, we attempted to synthesize an amphiphilic diblock copolymer poly(ethylene glycol)-polylysine (PEG-PLys) based on ring-opening polymerization. The γ terminal amines of lysine units were conjugated with camptothecin (CPT) through redox-responsive disulfide linkage, followed by conversion of the rest of the amines of PLys into carboxyl groups. Core-shell architectural nanoparticles could be achieved by self-assembly of the yielded amphiphiles characterized to possess CPT-linked PLys segments as the internal core and PEG segments as the external shell. Furthermore, attempts were made to precipitate CaPO3 on the yielded core with the aid of the carboxyl groups. Subsequent investigations confirmed uniform nanoscale formation with a hydrodynamic diameter of approximately 63.0 nm and excellent colloidal stabilities. Most importantly, the proposed dually responsive prodrug construct was determined to possess intriguing sequentially intracellular microenvironment-responsive functionalities: (1) the inorganic CaPO3 precipitate could not only exclude the internal payloads from premature reactions but also rapidly dissolve in acidic endosomal compartments, with the induced osmotic pressure thereby facilitating translocation of the prodrug into the cytosol; (2) CPT could be readily metabolized due to disulfide cleavage responsive to the redox potential in cytosolic compartments. Hence, the amalgamated dual-responsiveness eventually contributes to drastic cytotoxic potency, which portends prosperous utilities as precision therapeutics in the treatment of a variety of intractable tumors.

[Clinical study of the application of non-invasive porcelain veneer to improve the aesthetic effects in maxillary anterior area].

OBJECTIVE: To evaluate the clinical results of application of non-invasive porcelain veneer to reduce the black triangle of implant and adjacent teeth and to improve the aesthetic effect in the maxillary anterior area. METHODS: The study included 10 patients (Male: 4, Female: 6; average age: 41.5) accessioned during May 2007 to August 2009 in Peking University School of Stomatology. The provisional restorations were delivery on implant after 3-6 months healing period of the implant. The non-invasive porcelain veneers were used in the round tip adjacent teeth with gingival recession in the indicated patients. Main measured parameters on the model included horizontal distance and vertical distance. The Horizontal distance refers to the black triangle bottom which is from adjacent surface of the natural teeth to the implant restoration at the gingival level. The vertical distance is from mid-point of the triangle bottom to the contact point. Clinical observed items included bleeding index (BI), integrity of porcelain veneer and degree of satisfaction of the patients. RESULTS: A total of 14 adjacent natural teeth in 10 patients were cemented with porcelain veneer. No porcelain veneer was lost or fracture during follow-up period (range 6 to 27 months, mean of 10.4 months). Mean bleeding index 0-1. The horizontal distance was reduced from (3.1 + or - 0.8) mm before restoration to (1.1 + or - 0.5) mm after restoration. Vertical distance from (5.3 + or - 1.1) mm to (2.9 + or - 0.7) mm. All patients were satisfied with the clinical result. CONCLUSION: The data and the experience described in this study indicate that improvement of aesthetic effects by using no-invasive porcelain veneer techniques can be a predictable technique for patients with periodontal disease. Further study is needed to determine the long-term result of the technique.

Accuracy of multi-implant impressions using 3D-printing custom trays and splinting versus conventional techniques for complete arches.

PURPOSE: To assess the three-dimensional (3D) accuracy of multi-implant impressions for complete arches obtained using 3D printing technology, and to determine the clinical feasibility of this approach by comparing the results obtained with those obtained with conventional impression techniques. MATERIALS AND METHODS: A maxillary model matrix with four implant analogs was used to fabricate 10 stone reference models (control) to simulate edentulous patients. Ten 3D-printed impressions were made using polylactic acid custom open trays with component splinting (3D-printed group). To make 10 conventional impressions of the reference models, the poly(methyl methacrylate) open trays with splinting technique was used (conventional group). Impressions were poured with a type IV dental stone, which had been digitalized utilizing a high-resolution laboratory scanner after connecting the polymer scan bodies. Standard tessellation language (STL) datasets from the two groups of stone models were superimposed with the corresponding reference models. The interimplant distances and interimplant angulations for each implant pair were measured for the reference models and for the two test groups' definitive models, to assess 3D deviations. In addition, the mechanical properties of polylactic acid and poly(methyl methacrylate) tray materials were compared by means of three-point loading and tensile bond tests. The Student t test was used to compare the differences in implant position and mechanical properties between the two groups, while implant angulations were analyzed with Wilcoxon's rank-sum test, at P = .05. RESULTS: There was less implant-position deviation for the 3D-printed group (mean ± SD: 56.37 ± 12.52 µm) than for the conventional group (71.94 ± 18.86 µm) (P = .014). No significant differences were found in angular deviation between the two groups (P > .05). Flexural strength results suggested that polylactic acid (112.7 ± 1.62 MPa) was stronger than poly(methyl methacrylate) (104.0 ± 2.17 MPa; P < .0001). The tensile bond strength of polylactic acid (0.07 ± 0.005 MPa) was higher than that of poly(methyl methacrylate) (0.03 ± 0.004 MPa; P < .0001). CONCLUSION: The 3D-printing multi-implant impression technique could be an alternative to conventional impression techniques for complete arches.

[Clinical study of immediate post-extraction implant and immediate function in edentulous patients].

OBJECTIVE: To evaluate the outcomes of immediate post-extraction implant and immediate function according to All-on-4 immediate concept in edentulous patients. METHODS: The study included 46 patients with hopeless teeth. A total of 254 implants were immediately inserted after extraction and 56 fixed complete-arch all-acrylic prostheses finished and functioned on the day of extraction from June 2008 to March 2012 in Peking University School of Stomatology. At time of abutments connection, a panoramic radiograph was taken, and radiographic assessment of the marginal bone level was performed in every 6 months. Marginal bone level, integrity of the restoration, survival of the implants and degree of satisfaction of the patients were evaluated. RESULTS: A total of 254 implants were immediate loading. Thirteen implants were lost 6 - 8 weeks after immediate loading and the survival rate of 94.9% (241/254). The marginal bone absorption was (0.7 ± 0.3) mm on average. All patients were satisfied with the clinical results. CONCLUSIONS: Immediate post-extraction implant and immediate function technique can be a predictable technique. Further study is needed to determine the long-term results of the technology.

The All-on-Four implant therapy protocol in the management of edentulous Chinese patients.

PURPOSE: To evaluate the outcome and special characteristics of immediate implant rehabilitation using the All-on-Four treatment concept in completely or potentially completely edentulous Chinese patients. MATERIALS AND METHODS: A convenience sample consisted of 69 consecutive patients (37 men, 32 women; mean age: 56.7 years) treated with immediate implant placement and full-arch prosthodontic provisional prostheses between April 2008 and December 2011. Of 344 implants (192 mandibular, 152 maxillary), 240 implants were placed in fresh extraction sites. The remaining 104 implants were placed in healed sites. Implants were immediately loaded with a fixed full-arch provisional prosthesis. Implant survival rate, marginal bone loss, abutment selection, complications, and subjective patient responses were recorded during follow-up. RESULTS: Implant survival rate was 96.2% at 33.7 months of mean follow-up (range: 12 to 56 months). A statistically significantly higher implant survival rate was found in the mandible (99.0% vs 92.8%) (P < .05). No significant difference existed between survival rates for implants placed in postextraction sites and healed sites (P > .05). Peri-implant marginal bone loss around upright implants and tilted implants was 0.7 ± 0.2 mm and 0.8 ± 0.4 mm, respectively. All patients reported satisfactory treatment outcomes. CONCLUSIONS: The modified All-on-Four treatment concept provides predictably favorable outcomes in completely or potentially completely edentulous patients and is well suited to the sociodemographic needs of Chinese patients. Exploratory use of a surgical guide was limited because of mouth opening, and more angulated abutments were needed in anterior upright implants of the maxilla.

[Clinical study of prosthetic gingival reconstruction in vertical bone defect patients].

OBJECTIVE: To evaluate the preliminary clinical results of prosthetic gingival reconstruction in vertical bone defect patients. METHODS: The study included 31 partial or edentulous patients (male 22, female 9) with 152 implants supporting fixed prostheses from February 2002 to January 2011 in Peking University School and Hospital of Stomatology. The implant-supported fixed prostheses with artificial gingival material to compensate for vertical defect were delivery after implant healing period. At time of prostheses delivery, a panoramic radiograph was taken. The results were evaluated according to California Dental Association by two prosthodontists. Clinical observation included survival of the implants, integrity of the restoration, complication of prosthesis and degree of satisfaction of the patients. RESULTS: A total of 152 implants supported fixed prostheses with artificial gingival materials to compensate vertical bone defect were delivered. No implants lost, and the survival rate was 100% during the follow-up period. The sore of acceptance of prosthesis was 96.8%. All patients were satisfied with the clinical results. CONCLUSIONS: The artificial gingival reconstruction technique is feasible for vertical bone defect patients.

[Clinical study of "All-on-4" implant immediate function in edentulous patients].

OBJECTIVE: To evaluate the preliminary clinical results of application of All-on-4 immediate function in edentulous patients. METHODS: Twenty nine edentulous patients with 140 immediately loaded implants supporting fixed complete-arch all-acrylic prostheses from April 2008 to October 2009 in Peking University School of Stomatology were included. The implant-supported fixed complete-arch all-acrylic prostheses were delivery on the operation day. At time of abutments connection, a panoramic radiograph was taken. And radiographic assessment of the marginal bone level was performed in every 2 months. Clinical observe items included marginal bone level, integrity of the restoration, survival of the implants and degree of satisfaction of the patients. RESULTS: A total of 140 implants were immediate loading. Eight implants were lost during 6 - 8 weeks after immediate loading, giving survival rate of 94.3%. The marginal bone level was (0.8 ± 0.4) mm. The All patients were satisfied with the clinical results. CONCLUSIONS: The data and the experience described in this study indicate that All-on-four immediate function technique can be a predictable technique for edentulous patients. Further study is needed to determine the long-term result of the technology.

[Clinical study of implant-retained facial prosthesis].

OBJECTIVE: To evaluate clinical results and technical characteristics of implant-retained facial prosthesis. METHODS: Six patients with facial defects underwent implant retained prosthesis treatment, of which 3 orbita defects (including upper and lower eyelids, eyeball) in 3 cases, 2 ears defects in 2 cases, and a nose defect in one case. Under local anaesthesia 21 extra-oral implant were placed, facial prosthesis were individually made six month postoperatively. Follow up ranged from 6 month to 6 years. RESULTS: All 21 implants osseointegrated well, implant lost and peri implantitis was not found. All 6 cases had individual facial prosthesis and were satisfied with the prosthesis. CONCLUSIONS: Extra oral implants provided excellent retainment for facial prosthesis; result of current silicon with individual color shade is encouragable.