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1.
Artigo em Inglês | MEDLINE | ID: mdl-38873850

RESUMO

OBJECTIVES: To analyze the three-dimensional stability and morphologic changes of tent space after the osteotome sinus floor elevation (OSFE) procedures without bone grafts. MATERIALS AND METHODS: Forty-six implants placed using the OSFE technique with simultaneous implant placement without bone grafts were included in this retrospective study. Cone-beam computed tomography (CBCT) scans of the augmented sinuses were obtained pre- and postoperatively up to 48 months of follow-up. The maxillary sinus cavity profiles were outlined using three-dimensional virtual reconstruction and superimposition of CBCT scans. The three-dimensional changes in the tent space were measured. A generalized estimating equation (GEE) was used to explore potential factors. RESULTS: The implant survival rate was 97.8%. The mean volume of remaining tent space immediately after surgery was 96.8 ± 70.5 mm3, shrinking to 31.0 ± 24.9 mm3 after 48 months, while the mean percentage of remaining tent space volume decreased to 29.1 ± 20.7%. The tent space volume and the percentage of residual tent space volume only decreased significantly within 12 months after surgery (p = .008, .013). GEE results indicated positive correlations between the percentage of remaining tent space volume and implant protrusion length (p = .000) and apical height (p = .000), with a negative correlation between the sinus floor area immediately after surgery (p = .002) and the healing time (p = .022). CONCLUSIONS: The volume of the tent space rapidly shrank after OSFE without bone grafts. Several factors might influence the tent space stability. Long-term clinical trials with larger sample sizes are necessary to further validate the results.

2.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-38832462

RESUMO

With the rapid development of implant techniques and digital technology, digital impressions have become a commonly used impression method in implant restoration. At present, the accuracy of intraoral digital impressions directly applied to implant-supported full-arch prostheses remains inadequate, which is due to the high accuracy requirement of full-arch implant impressions, while there are still technical challenges in intraoral digital impressions about recognition and stitching. In this regard, scholars have proposed a variety of scanning strategies to improve the accuracy of intraoral scan, including mucosal modifications, auxiliary devices and novel scan bodies. At the same time photogrammetry, as a new digital impression technique, has been developing steadily and exhibits promising accuracy. This article reviews the research progress on the accuracy of edentulous full-arch implant impressions and techniques which can improve the accuracy of intraoral digital impressions, to provide reference for clinical application.

3.
Arch Biochem Biophys ; 743: 109621, 2023 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-37209766

RESUMO

Gastric ulcer (GU) is a prevalent and life-threating gastrointestinal disorder. Aldehyde dehydrogenase 2 (ALDH2) is a pivotal component of alcohol metabolism which has been supported to suppress oxidative stress-elicited DNA damage in gastric mucosa cells. Nonetheless, whether ALDH2 is also involved in GU remains indistinct. Firstly, HCl/ethanol-induced experimental rat GU model was successfully established. RT-qPCR and Western blot tested ALDH2 expression in rat tissues. Following the addition of ALDH2 activator Alda-1, gastric lesion area and index were measured. H&E staining detected the histopathology of gastric tissues. ELISA examined the levels of inflammatory mediators. Alcian blue staining evaluated mucus production of gastric mucosa. Oxidative stress levels were estimated by corresponding kits and Western blot. Western blot examined the expression of NLRP3 inflammasome- and ferroptosis-related proteins. Prussian blue staining and corresponding assay kits measured ferroptosis. In ethanol-treated GES-1 cells, NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, iron content, ferroptosis, inflammation and oxidative stress were detected as aforementioned above. In addition to that, DCFH-DA staining examined ROS generation. The experimental data corroborated that ALDH2 expression was declined in the tissues of HCl/ethanol-treated rats. Alda-1 ameliorated HCl/ethanol-stimulated gastric mucosal damage, inflammatory response, oxidative stress, NLRP3 inflammasome activation and ferroptosis in rats. Also, the suppressive role of ALDH2 in inflammatory response and oxidative stress was reversed by ferroptosis activator erastin or NLRP3 activator nigericin in HCl/ethanol-challenged GES-1 cells. To be summarized, ALDH2 might play the protective role in the process of GU.


Assuntos
Ferroptose , Úlcera Gástrica , Ratos , Animais , Inflamassomos/metabolismo , Etanol/toxicidade , Aldeído-Desidrogenase Mitocondrial/genética , Aldeído-Desidrogenase Mitocondrial/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/tratamento farmacológico , Estresse Oxidativo
4.
Clin Oral Implants Res ; 34(3): 243-253, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36727924

RESUMO

OBJECTIVES: To evaluate the associations between the cortical bone-to-implant contact (CBIC), bone microstructure derived from cone-beam computed tomography (CBCT), and the primary stability of the implant. MATERIALS AND METHODS: Twenty-two patients with 65 implants were enrolled in this study. The peak insertion torque values (ITVs) were measured during implant insertion, and the implant stability quotient (ISQ) values were measured immediately after implant placement and 3 months after surgery. The profiles of the peri-implant bone structure were outlined using the volumetric reconstruction of the CBCTs and superimposition of the virtual models, and the features of CBIC and bone microstructure parameters were measured. The linear mixed effects model and generalized estimating equation were used to explore the predictors for implant primary stability. RESULTS: The average ITV, baseline, and secondary ISQ values were 31.44 ± 6.54 N·cm, 73.34 ± 7.39, and 80.32 ± 4.58, respectively. Statistically significant correlations were found between ITV and surface area of CBIC (r = .340, p = .006), bone volume fraction (r = .294, p = .017), and bone surface fraction (r = -.278, p = .039). Implants with buccolingual CBIC had a higher ITV than implants without CBIC (p = .016). None of the parameters were associated with baseline and secondary ISQ values in generalized estimating equation analysis (all p > .05). CONCLUSIONS: Within the limitations of the study, preoperative CBCT measurements might enable the prediction of ITV and therefore of implant primary stability values.


Assuntos
Implantes Dentários , Tomografia Computadorizada de Feixe Cônico Espiral , Humanos , Implantação Dentária Endóssea/métodos , Densidade Óssea , Osso Cortical , Torque
5.
Eur J Oral Sci ; 131(3): e12928, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36931874

RESUMO

In this study, the synergistic effect of glutaraldehyde-cross-linking and remineralization on the strength and durability of resin-dentin bonds was investigated. Dentin surfaces were etched with 35% phosphoric acid. The control specimens were bonded with Adper Single Bond 2 using wet bonding without pretreatment. The experimental specimens were pretreated with 5% (v/v) glutaraldehyde solution for 3 min and placed in a remineralizing solution for 0, 12, and 24 h, followed by dry bonding. After performing composite build-ups on the specimens, they were longitudinally sectioned, immediately, and after aging for 3 h with sodium hypochlorite (NaOCl), to evaluate microtensile bond strength (µTBS). The cross-linked specimens exhibited µTBS values comparable with those of the control group, but the µTBS decreased significantly after NaOCl aging. The cross-linked dentin remineralized for 24 h exhibited an increase in µTBS. After aging in NaOCl, the µTBS of the specimens remineralized for 24 h did not decrease and was significantly higher than for the other experimental groups. Cross-linking with dry bonding maintained µTBS in specimens before aging in NaOCl, but the bonding durability was compromised. Remineralization of cross-linked dentin for 24 h followed by dry bonding increased the immediate µTBS and improved bond durability. Therefore, combining cross-linking with remineralization of collagen fibrils progressively increased resistance to degradation, improving bond durability.


Assuntos
Colagem Dentária , Adesivos Dentinários , Adesivos Dentinários/química , Glutaral/farmacologia , Cimentos de Resina/química , Teste de Materiais , Colágeno , Dentina , Resistência à Tração
6.
J Prosthet Dent ; 2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36964046

RESUMO

Patients with traumatic dental injuries commonly present in clinical practice with complex crown-root fractures. Prosthodontic treatment of such patients may be unsuccessful because of the violation of the supracrestal tissue attachment, making their management challenging. Minor tooth movement is an effective solution to extruding the residual root but may require referral to an orthodontist. The purpose of this technique was to present a digital orthodontic system including a 3-dimensional virtual patient technique, a computer-aided design and computer-aided manufacture (CAD-CAM) resin facial veneer-retained pontic, and a zirconia post as an orthodontic appliance for tooth extrusion in the esthetic zone. This veneered pontic may also serve as an interim prothesis. The appliance provides a precise design for the direction and extent of orthodontic extrusion.

7.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 52(1): 126-133, 2023 Feb 25.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-37283126

RESUMO

Bone stability is precisely controlled by osteoclast-mediated bone resorption and osteoblast-mediated bone formation. When the balance is broken, the integrity of the bone structure will be destroyed. Inflammasomes are important protein complexes in response to pathogen-related molecular models or injury-related molecular models, which can promote the activation and secretion of proinflammatory cytokines and activate a local inflammatory response. NOD-like receptor thermal protein domain associated protein (NLRP) 3 inflammasome can promote bone resorption through the activation of the proinflammatory cytokines interleukin (IL)-1ß, IL-18 and the induction of caspase-1-mediated pyroptosis. Inhibiting the production of NLRP3 inflammasome may be beneficial to improve comfort and bone stability. The presence of metal particles and microorganisms around implants can activate NLRP3 and promote bone absorption. NLRP3 inflammasome plays an important role in the maintenance of bone stability around implants, however, most studies focus on orthopedic implants and periodontitis. This article reviews the effects of NLRP3 inflammasome on bone formation, resorption and pain induced by implants, and the possibility of NLRP3 as a target for preventing peri-implantitis is discussed.


Assuntos
Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Citocinas , Caspase 1 , Interleucina-1beta/metabolismo
8.
J Prosthet Dent ; 128(5): 919-927, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33795161

RESUMO

STATEMENT OF PROBLEM: Guided bone regeneration (GBR) is widely used to reconstruct peri-implant bone defects in the esthetic zone. However, the dimensional stability of this bone-biomaterial composite is not fully understood. PURPOSE: The primary aim was to evaluate the hard tissue 3-dimensional (3D) stability around single implants placed with simultaneous GBR by using deproteinized bovine bone mineral (DBBM) in the anterior maxilla and explore possible influencing factors. MATERIAL AND METHODS: The records of patients who had received implants in the anterior maxilla from January 2015 to March 2016 were reviewed retrospectively. The change in volume and thickness of the facial hard tissue were analyzed. To explore possible influencing factors, the thickness and surface area of facial graft were measured, and the time point at which implants were placed and the healing protocol were recorded. Secondary outcome measures were peri-implant marginal bone loss, bleeding on probing (BOP), and pink esthetic score (PES). Statistical analysis was conducted by using the Student t test, Mann-Whitney U test, Kruskal-Wallis test, or generalized estimating equation analysis (α=.05). RESULTS: Fifty-five participants were included in this study, and no implants had been lost after 3 years. BOP was present in 10 (18.2%) participants. The mean ±standard deviation PES of all implants for this study was 11.0 ±2.1. The mean ±standard deviation percentage of residual hard tissue volume was 36.9 ±23.5%, with a significant difference found between time points before 9 months (P<.05). Type 3 implant placement (OR=1.449, P=.031) was found to have a higher percentage of residual hard tissue volume. A greater reduction of the facial hard tissue thickness was observed in participants with thicker postoperative facial grafting (OR=1.463, P=.001). No statistically significant difference was found between the facial, palatal, mesial, and distal peri-implant sites in terms of marginal bone loss (P>.05). CONCLUSIONS: Although single-tooth implant placement combined with GBR using DBBM in the anterior maxilla offered satisfactory esthetic and functional outcomes after a 3-year follow-up, significant hard tissue volume and thickness reduction in grafted sites was detected, especially during the initial 9-month postoperative period. This phenomenon may be correlated with the timing of implant placement and the thickness of the facial graft.


Assuntos
Implantes Dentários para Um Único Dente , Implantes Dentários , Humanos , Bovinos , Animais , Maxila/cirurgia , Estudos Retrospectivos , Estética Dentária , Regeneração Óssea , Resultado do Tratamento , Implantação Dentária Endóssea/métodos
9.
BMC Oral Health ; 22(1): 335, 2022 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-35945572

RESUMO

BACKGROUND: To evaluate and compare the clinical outcomes of digitally prefabricated and conventionally fabricated implant-supported full-arch provisional prostheses. METHODS: In this retrospective study, a total of 39 patients (22 males and 17 females) who underwent implant-supported full-arch rehabilitation using the All-on-4 concept with an immediate loading protocol were included: 20 patients treated with digitally prefabricated provisional prostheses were assigned into Group A, and 19 patients treated with conventionally fabricated provisional prostheses were assigned into Group B. Implant/provisional prosthesis survival rates and complications were reviewed. Marginal bone loss (MBL) was investigated by CBCT. Surgical time, restorative time, and total operative time were analyzed. Postoperative pain and swelling were evaluated with the visual analog scale (VAS). The oral health impact profile (OHIP) questionnaire was administered before and after surgery. RESULTS: The implant/provisional prosthesis survival rate was 100%, and complications appeared with low frequency in both groups, while the mean MBL was 0.30 ± 0.29 mm in Group A and 0.31 ± 0.41 mm in Group B after 3~ 6 months (P > 0.05). The average restorative time in Group A (116.16 ± 16.61 min) was significantly shorter than that in Group B (242.11 ± 30.14 min) (P < 0.05). Patients in Group A showed lower pain/swelling VAS scores after surgery than Group B (P < 0.05). Low OHIP scores with high satisfaction with the overall effects were shown in both groups. CONCLUSION: Prefabricated prostheses reduced the prosthetic time and postoperative discomfort in patients whose immediate rehabilitation was based on the All-on-4 concept. This prefabrication technology may be a predictable alternative to improve the short-term clinical outcome of implant-supported full-arch provisional rehabilitation.


Assuntos
Implantes Dentários , Carga Imediata em Implante Dentário , Prótese Dentária Fixada por Implante , Feminino , Seguimentos , Humanos , Masculino , Falha de Prótese , Estudos Retrospectivos , Resultado do Tratamento
10.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 51(1): 102-107, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35576112

RESUMO

Magnetic nanoparticles (MNP) have been widely used as biomaterials due to their unique magnetic responsiveness and biocompatibility, which also can promote osteogenic differentiation through their inherent micro-magnetic field. The MNP composite scaffold retains its superparamagnetism, which has good physical, mechanical and biological properties with significant osteogenic effects and . Magnetic field has been proved to promote bone tissue repair by affecting cell metabolic behavior. MNP composite scaffolds under magnetic field can synergically promote bone tissue repair and regeneration, which has great application potential in the field of bone tissue engineering. This article summarizes the performance of magnetic composite scaffold, the research progress on the effect of MNP composite scaffold with magnetic fields on osteogenesis, to provide reference for further research and clinical application.


Assuntos
Nanopartículas de Magnetita , Osteogênese , Diferenciação Celular , Engenharia Tecidual , Alicerces Teciduais
11.
BMC Oral Health ; 21(1): 478, 2021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-34579702

RESUMO

BACKGROUND: To elucidate the anatomical features of the mandibular molar region to allow safe immediate implant placement. METHODS: Cone-beam computed tomography images of 150 patients (600 teeth) were reviewed retrospectively. The virtual implants were placed in the mandibular first and second molar region. The anatomic structures of the mandible and inter-radicular septum were both categorized into three types. The relationship between implant and inferior alveolar nerve (IAN), and the horizontal distance from the implant surface to the bone wall were analyzed. Variables were compared using a student's t-test, or Mann-Whitney U test. RESULTS: Type U (39.0%) and type S (56.0%) were the most common in the first molar, while type U (67.7%) and type M (54.7%) had the highest prevalence rate in the second molar. The mean distance from the level where the virtual implant was completely surrounded by bone to IAN was 7.06 mm. The mean horizontal widths from the implant to the mesial and distal socket wall were 1.59 mm and 1.89 mm. The widths of the inter-radicular septum and the distances from implant to the buccal and lingual plate on different sections were significantly associated with tooth position (P < .05). CONCLUSIONS: In the first molar region, the implant is suggested to be placed in the center of the inter-radicular septum, while in the second molar region, the mesial root socket could be considered. Immediate implant placement in the mandibular second molar sockets shows a high risk of IAN injury, lingual perforation, and inadequate primary stability.


Assuntos
Implantes Dentários , Tomografia Computadorizada de Feixe Cônico , Humanos , Mandíbula/diagnóstico por imagem , Dente Molar/diagnóstico por imagem , Estudos Retrospectivos
12.
Med Sci Monit ; 26: e919460, 2020 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-31927557

RESUMO

BACKGROUND Small nuclear ribonucleoproteins (snRNPs) complexes of protein and noncoding RNA accumulate in the cell nucleus and catalyze pre-mRNA splicing to form the spliceosome. This study aimed to investigate the role of the spliceosome, splicing factor 3b subunit 1 (SF3B1), in AGS and MKN28 human gastric cancer cells in vitro, including gene knockdown with small interfering RNA (siRNA), and the use of the selective mRNA splicing inhibitor of SF3B1, pladienolide B. MATERIAL AND METHODS In AGS and MKN28 human gastric cancer cells, SF3B1expression was inhibited with siRNA and pladienolide B. Following SF3B1 inhibition, the Cell Counting Kit-8 (CCK-8) assay measured cell proliferation, and flow cytometry was used to investigate cell apoptosis and cell cycle arrest. The downstream HOXA10 and AKT pathways were studied by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot. The presence of alternative splicing, or differential splicing, of single-gene coding for multiple proteins, was analyzed using The Cancer Genome Atlas (TCGA) SpliceSeq. RESULTS Inhibition of SF3B1 reduced the proliferation rate of AGS and MKN28 human gastric cancer cells by inducing apoptosis and G2/M phase arrest. SF3B1 knockdown resulted in reduced homeobox A10 (HOXA10) mRNA expression and expression of long noncoding RNA (lncRNA) isoforms of HOXA10 (exons 1 and 3) and HOXA10 (exons 2 and 3). SF3B1 inhibition increased PTEN levels and reduced AKT protein phosphorylation. CONCLUSIONS In AGS and MKN28 human gastric cancer cells in vitro, inhibition of SF3B1 reduced cell proliferation, induced apoptosis, and resulted in cell cycle arrest by regulating HOXA10 splicing.


Assuntos
Apoptose , Pontos de Checagem do Ciclo Celular , Proteínas Homeobox A10/metabolismo , Fosfoproteínas/metabolismo , Fatores de Processamento de RNA/metabolismo , Neoplasias Gástricas/patologia , Processamento Alternativo/genética , Apoptose/efeitos dos fármacos , Apoptose/genética , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Compostos de Epóxi/química , Compostos de Epóxi/farmacologia , Éxons/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Proteínas Homeobox A10/genética , Humanos , Macrolídeos/química , Macrolídeos/farmacologia , Fosfoproteínas/genética , Fatores de Processamento de RNA/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Neoplasias Gástricas/genética
13.
J Prosthet Dent ; 123(4): 622-629, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31383528

RESUMO

STATEMENT OF PROBLEM: Residual cement is detrimental to the long-term success of dental implants with a cement-retained restoration. The complete elimination of excess cement remains a challenge. PURPOSE: The purpose of this in vitro study was to evaluate the effects of precementation technique on minimizing the residual cement and retention of restorations. MATERIAL AND METHODS: Four custom cobalt-chromium alloy (Co-Cr) abutments were manufactured by computer-aided design and computer-aided manufacturing (CAD-CAM) as precementation abutments with height and radius reductions of 25 µm (A25), 50 µm (A50), 75 µm (A75), and 100 µm (A100). Fifty CAD-CAM-fabricated standard Co-Cr abutments and corresponding crowns were randomly matched and treated as follows: 10 specimens were cemented with the conventional cementation procedure with glass ionomer cement (G0), and 40 were precemented with precementation abutments (n=10) before the definitive cementation with standard abutments (G25, G50, G75, G100). The weight of the cement in the cement space was calculated, and the marginal sealing was evaluated by using a stereoscopic microscope. The effects of precementation with resin cement on minimizing residual cement around the marginal area of dental implants were further evaluated extraorally. The influence of precementation with glass ionomer and resin cement on the retention force was analyzed by using a universal testing machine at a crosshead speed of 0.5 mm/min. One-way ANOVA was used to analyze cement mass and marginal sealing values. Two-way ANOVA was used to compare the retention forces (α=.05). RESULTS: The cement weight of G50 (7.2 ±0.6 mg) was significantly higher than that of G25 (6.0 ±1.1 mg, P<.05), while no significant differences in cement weights were found among G50, G75, and G100. Consistently, the G50, G75, and G100 had higher marginal sealing values than that of the G25 (P<.01). Extraoral experiments showed that the precementation with A50 reduced subgingival residual cement without affecting retention. CONCLUSIONS: These in vitro results suggest that precementation with a precisely manufactured precementation abutment minimized the residual cement around implant abutments, and 50 µm could be a preferable precementation space.


Assuntos
Implantes Dentários , Cimentação , Desenho Assistido por Computador , Coroas , Dente Suporte , Cimentos Dentários , Planejamento de Prótese Dentária , Retenção em Prótese Dentária , Cimentos de Ionômeros de Vidro
14.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 49(1): 124-130, 2020 05 25.
Artigo em Chinês | MEDLINE | ID: mdl-32621418

RESUMO

For complex implant cases, simple implantation could not achieve the desired therapeutic effect, and a multidisciplinary approach has become a general trend. Orthodontic treatment before implantation creates favorable conditions for subsequent implantation by increasing restoring three-dimensional space, improving occlusion of patients. It also stimulates the increase of autologous soft and hard tissue while biological potential of periodontal ligament is fully developed. The choice of operation time is vital to keep the level of soft and hard tissue at the implantation site, which improves the curative effect of implantation in terms of function and aesthetics. In this article, the orthodontic-implant combined therapy is briefly reviewed focusing on the three-dimensional space optimization, implant site enhancement by orthodontic extrusion and delayed orthodontic space opening.


Assuntos
Implantes Dentários , Extrusão Ortodôntica , Ortodontia , Implantes Dentários/tendências , Humanos , Ortodontia/métodos , Ortodontia/tendências
15.
J Prosthet Dent ; 120(5): 658-667, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29961634

RESUMO

STATEMENT OF PROBLEM: Immediate implantation has been established to shorten waiting time before definitive restoration, offering the ability to deliver a predictable esthetic and functional outcome for patients. However, this approach remains controversial for a tooth with a periodontal or periapical lesion. PURPOSE: The purpose of this systematic review was to analyze the treatment outcomes of immediate implant placement into extraction sockets with or without infection of periodontal or periapical origin in the esthetic zone and to provide treatment protocols based on current studies. MATERIAL AND METHODS: An electronic search was performed in PubMed, ISI Web of Knowledge, and the Cochrane Library between January 2009 and October 2017. A subsequent manual search included all clinical studies published in the English language and excluded any reviews or animal studies. An article quality assessment scale, Newcastle-Ottawa Scale (NOS), was used to evaluate the quality of studies enrolled. The implant survival rate was expressed as risk ratio, whereas bone level changes and gingiva level changes were expressed as mean differences in millimeters with 95% confidence intervals. The meta-analysis was conducted by using commercial software. RESULTS: The search initially found 1171 references. The manual search of the reference lists of identified articles yielded additional papers. Altogether, 9 studies were identified within the selection criteria, with NOS scores between 5 and 8. Compared with the healthy sites, immediate implant placement in infected sites in the esthetic zone showed similar survival rates (97.6% vs. 98.4%, respectively; risk ratio [RR], 0.99; 95% confidence interval [CI], 0.97 to 1.00; P=.138). No statistically significant differences were found in bone level changes (mean difference [MD], 0.03; 95%CI, -0.09 to 0.14; P=.667) or in gingiva level changes (MD, -0.06; 95% CI, -0.13 to 0.01; P=.070) between the 2 groups. CONCLUSIONS: Meta-analysis showed that immediate implant placement into infected sites and noninfected sites in esthetic zone had similar survival rates, bone level changes, and gingiva level changes.


Assuntos
Carga Imediata em Implante Dentário/métodos , Periodontite Periapical , Estética Dentária , Humanos , Alvéolo Dental/cirurgia
16.
J Biomol NMR ; 67(4): 273-282, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28365903

RESUMO

Lanthanoid pseudo-contact shift (PCS) provides long-range structural information between a paramagnetic tag and protein nuclei. However, for proteins with native cysteines, site-specific attachment may only utilize functional groups orthogonal to sulfhydryl chemistry. Here we report two lanthanoid probes, DTTA-C3-yne and DTTA-C4-yne, which can be conjugated to an unnatural amino acid pAzF in the target protein via azide-alkyne cycloaddition. Demonstrated with ubiquitin and cysteine-containing enzyme EIIB, we show that large PCSs of distinct profiles can be generated for each tag/lanthanoid combination. The DTTA-based lanthanoid tags are associated with large magnetic susceptibility tensors owing to the rigidity of the tags. In particular, introduction of the DTTA-C3 tag affords intermolecular PCSs and enables structural characterization of a transient protein complex between ubiquitin and a UBA domain. Together, we have expanded the repertoire of paramagnetic tags and the applicability of paramagnetic NMR.


Assuntos
Aminoácidos/química , Elementos da Série dos Lantanídeos/química , Ressonância Magnética Nuclear Biomolecular/métodos , Proteínas/química , Alcinos/química , Animais , Azidas/química , Proteínas de Bactérias , Reação de Cicloadição/métodos , Humanos , Ácido Pentético/análogos & derivados , Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/química , Marcadores de Spin , Ubiquitina/química
17.
Angew Chem Int Ed Engl ; 56(4): 1002-1006, 2017 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-27990729

RESUMO

A protein can be in different conformations when fulfilling its function. Yet depiction of protein structural ensembles remains difficult. Here we show that the accurate measurement of solvent paramagnetic relaxation enhancement (sPRE) in the presence of an inert paramagnetic cosolute allows the assessment of protein dynamics. Demonstrated with two multi-domain proteins, we present a method to characterize protein microsecond-millisecond dynamics based on the analysis of the sPRE. Provided with the known structures of a protein, our method uncovers an ensemble of structures that fully accounts for the observed sPRE. In conjunction with molecular dynamics simulations, our method can identify protein alternative conformation that has only been theorized before. Together, our method expands the application of sPRE beyond structural characterization of rigid proteins and complements the established PRE NMR technique.


Assuntos
Simulação de Dinâmica Molecular , Proteínas/química , Conformação Proteica , Solventes/química
18.
J Gambl Stud ; 31(2): 585-606, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23979590

RESUMO

This article presents a trade based theory of casino taxation along with empirical evidence found from Macao as a typical tourism resort. We prove that there is a unique optimum gaming tax in a particular market for casino gambling, argue that any change in this tax is engendered by external demand shifts, and suggest that the economic rent from gambling legalization should be shared through such optimal tax between the public and private sectors. Our work also studies the tradeoff between economic benefits and social costs arising from casino tourism, and provides some policy recommendations for the sustainable development of gaming-led economies. The theoretical arguments in this article turn out to be consistent with empirical observations on Macao realities over the recent decade.


Assuntos
Comércio/economia , Administração Financeira/economia , Jogo de Azar/economia , Impostos/estatística & dados numéricos , Administração Financeira/estatística & dados numéricos , Humanos , Macau , Política Pública/economia , Políticas de Controle Social
19.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 44(1): 90-4, 2015 01.
Artigo em Chinês | MEDLINE | ID: mdl-25851982

RESUMO

OBJECTIVE: To investigate the effect of occlusal reconstruction on blood flow velocity and cerebral oxygen saturation in patients with malocclusion. METHODS: Thirty-three patients with malocclusion treated with occlusal reconstruction in Department of Stomatology, Medical School of Huzhou Normal College from Feb 2011 to Oct 2013 were enrolled in the study. The systolic peak flow velocity (vs), end-diastolic peak flow (vd) , mean peak flow velocity (vm) of middle cerebral artery and the oxygen saturation (rScO2) in the brain were detected at rest or chewing status by using transcranial Doppler color ultrasonography and near-infrared spectroscopy, respectively. RESULTS: In rest state, vm was significantly increased on 3 months after treatment, while vs and vd were significantly increased on 6 months after treatment and rScO2 were increased on 12 months after treatment (P<0.05). In chewing state, vs, vm, and rScO2 were increased on 3 months after treatment, and vd was increased on 6 months after treatment (P<0.05). CONCLUSION: Occlusal reconstruction can increase blood flow velocity of middle cerebral artery and cerebral oxygen saturation and improve oxygen supply of the brain in patients with malocclusion.


Assuntos
Circulação Cerebrovascular , Má Oclusão/cirurgia , Oxigênio/fisiologia , Procedimentos de Cirurgia Plástica , Velocidade do Fluxo Sanguíneo , Encéfalo/irrigação sanguínea , Encéfalo/fisiologia , Humanos , Ultrassonografia Doppler Transcraniana
20.
J Biomol NMR ; 58(3): 149-54, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24510274

RESUMO

Solvent paramagnetic relaxation enhancement (sPRE) arises from random collisions between paramagnetic cosolvent and protein of interest. The sPRE can be readily measured, affording protein structure information. However, lack of an inert cosolvent probe may yield sPRE values that are not consistent with protein structure. Here we synthesized a new sPRE probe, triethylenetetraamine hexaacetate trimethylamide gadolinium, or Gd(III)-TTHA-TMA. With a total of 10 coordination sites, this paramagnetic cosovlent eliminates an inner-sphere water molecule that can otherwise transfer relaxation to protein through exchange. With the metal ion centered, the new probe is largely spherical with a radius of 4.0 Å, permitting accurate back calculation of sPRE. The effectiveness Gd(III)-TTHA-TMA as a sPRE probe was demonstrated on three well-studied protein systems.


Assuntos
Ácido Edético/análogos & derivados , Gadolínio/química , Proteínas/química , Ácido Edético/química , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Espectroscopia de Ressonância Magnética , Ressonância Magnética Nuclear Biomolecular/métodos , Proteínas/ultraestrutura , Água/química
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