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1.
Opt Express ; 30(11): 18300-18309, 2022 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-36221634

RESUMO

We propose a three-axis closed-loop optically pumped magnetometer with high sensitivity. The closed-loop magnetometer has a three-axis sensitivity of approximately 30 fT/Hz1/2 using two orthogonal laser beams for pumping and probing the alkali metal atoms. In the closed-loop mode, the dynamic range is improved from ±5 nT to ±150 nT. The bandwidth is increased from about 100 Hz to over 2 kHz with 10 kHz modulation fields in x- and y-axes and another 6 kHz modulation field along the z-axis. Compared with single-axis or dual-axis magnetometers, the proposed magnetometer not only provides the direction and magnitude of the magnetic field but also has high robustness in a challenging environment. The magnetometer has applications in biomagnetic measurements, magnetic resonance imaging, and fundamental physics.

2.
Am J Orthod Dentofacial Orthop ; 160(2): 302-311, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34332692

RESUMO

INTRODUCTION: Computer-aided design and manufacturing of orthodontic retainers from digitally debonded models can be used to facilitate same-day delivery. The purpose of this prospective clinical study was to validate a novel technique for virtual bracket removal (VBR) in-office, comparing the accuracy with 2 orthodontic laboratories that use VBR for retainer fabrication in the digital workflow. METHODS: The sample consisted of 40 intraoral scans of 20 patients. Four groups were compared. The scans without brackets were used as a control group. VBR was performed by 3 groups: In-office VBR (Software Meshmixer, version 3.5.474; Autodesk, San Rafael, Calif), Orthodent Laboratory (ODL; Buffalo, NY), and New England Orthodontic Laboratory (NEOLab; Andover, Mass). The virtually debonded models were superimposed onto the control models using surface-based registration. Regional 3-dimensional Euclidean distances between surface points of superimposed models were calculated for comparative analysis of surface changes after VBR using Vector Analysis Module (Canfield Scientific, Fairfield, NJ) software. RESULTS: The accuracy of VBR using the Meshmixer did not differ significantly from the VBR protocols used by the 2 laboratories. However, there was a statistically significant difference between the 2 laboratories, with ODL showing lower accuracy than NEOLab. Although some differences were statistically significant, they were very small and not considered clinically relevant. There was also a statistically significant difference between the 3 tooth segments (incisors, canines/premolars, and first molars), with VBR of the first molars and second premolars showing the least accuracy. CONCLUSIONS: The VBR techniques using the in-office Meshmixer, ODL, and NEOLab were considered accurate enough for the clinical use of orthodontic retainers fabricated from printed models.


Assuntos
Braquetes Ortodônticos , Contenções Ortodônticas , Dente Pré-Molar , Desenho Assistido por Computador , Humanos , Dente Molar , Estudos Prospectivos
3.
J Adv Prosthodont ; 12(3): 157-166, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32601535

RESUMO

PURPOSE: The aim of this study was to evaluate the clinical performance and reliability of plasma sprayed nanostructured zirconia (NSZ) coating. MATERIALS AND METHODS: This study consisted of three areas of analysis: (1) Mechanical property: surface roughness of NSZ coating and bond strength between NSZ coating and titanium specimens were measured, and the microstructure of bonding interface was also observed by scanning election microscope (SEM). (2) Biocompatibility: hemolysis tests, cell proliferation tests, and rat subcutaneous implant test were conducted to evaluate the biocompatibility of NSZ coating. (3) Mechanical compatibility: fracture and artificial aging tests were performed to measure the mechanical compatibility of NSZ-coated titanium abutments. RESULTS: In the mechanical study, 400 µm thick NSZ coatings had the highest bond strength (71.22 ± 1.02 MPa), and a compact transition layer could be observed. In addition, NSZ coating showed excellent biocompatibility in both hemolysis tests and cell proliferation tests. In subcutaneous implant test, NSZ-coated plates showed similar inflammation elimination and fibrous tissue formation processes with that of titanium specimens. Regarding fatigue tests, all NSZ-coated abutments survived in the five-year fatigue test and showed sufficient fracture strength (407.65-663.7 N) for incisor teeth. CONCLUSION: In this study, the plasma-sprayed NSZ-coated titanium abutments presented sufficient fracture strength and biocompatibility, and it was demonstrated that plasma spray was a reliable method to prepare high-quality zirconia coating.

4.
Prog Orthod ; 20(1): 24, 2019 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-31209589

RESUMO

BACKGROUND: The purpose of this study was to evaluate the treatment effectiveness of Carriere Distalizer in comparison to Class II intermaxillary elastics and Forsus. METHODS: Three groups of patients treated with Class II intermaxillary elastics (n = 18), Carriere Distalizer (n = 18), and Forsus appliance (n = 18) were collected from three private orthodontic practices. Inclusion criteria were as follows: (1) 10-14 years old of start age with permanent dentition, (2) no history of previous orthodontic treatment, (3) complete pre- and post-treatment records, (4) dental Class II division 1 (end-to-end or more), (5) no pre-treatment transverse discrepancy, (6) non-extraction treatment plan, and (7) Class I post-treatment occlusal relationship. The data consisted of cephalometric and study model measurements from pre- and post-treatment records and treatment time. Two-tail Student t test was used to analyze the differences in cephalometric changes and dental corrections between Carriere Distalizer group and Class II elastics/Forsus group. RESULTS: All three groups of patients showed no differences in the age of treatment initiation, pre-treatment cephalometric measurements and discrepancy index (DI). The time of Class II correction for Carriere Distalizer was significantly shorter than that for Class II elastics; there was no difference in the length of Class II correction between Carriere Distalizer and Forsus groups. The amount of Class II correction (canine/molar relationship) was significantly lower for Carriere Distalizer when compared with Forsus appliance. Carriere Distalizer, similarly to Class II elastics, did not induce any statistically significant correction in skeletal component (ANB and Wits appraisal). CONCLUSIONS: There is no clinically significant skeletal correction induced by Carriere Distalizer in growing patients. Carriere Distalizer can be applied to treatment of mild to moderate Class II dental malocclusion over 6 months on average, although the total treatment time may be prolonged due to various side effects. Overall, the Carriere Distalizer appears to be no more effective or efficient than alternatives in the treatment of Class II malocclusion.


Assuntos
Má Oclusão Classe II de Angle , Aparelhos Ortodônticos Funcionais , Sobremordida , Adolescente , Cefalometria , Criança , Humanos , Resultado do Tratamento
5.
Cell Biosci ; 8: 55, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30386554

RESUMO

BACKGROUND: Fine osseointegration is the basis of long-term survival of implant. In our previous study, we observed a strong correlation between hyperlipidemia and compromised osseointegration. MicroRNA-29a-3p (miR-29a-3p) has been discovered to participate in bone marrow mesenchymal stem cells (BMSCs) differentiation. However, the role and the underlying mechanisms of hyperlipidemia and miR-29a-3p in osseointegration still remain obscure. RESULTS: In peri-implant bone tissues of hyperlipidemia rats, bone mass, mineralization and bone trabecula formation were weakened. Alkaline phosphatase (ALP) and runt-related transcription factor 2 (Runx2), and miR-29a-3p expression were reduced. While in normal rats, implant-bone interfaces were filled with dense new bone and ALP, Runx2 and miR-29a-3p were up-regulated. Overexpressed miR-29a-3p can reverse the adverse effect of hyperlipidemia on osseointegration. Implants were tightly integrated with the surrounding dense new bone tissues, and ALP as well as Runx2 mRNAs were enhanced in miR-29a-3p overexpressed and hyperlipidemia rats, while little peri-implant bone tissue existed, ALP and Runx2 deregulated on miR-29a-3p inhibited rats. Dishevelled 2 (Dvl2) mRNA was declined in peri-implant bone tissue of high-fat (HF) group than normal group, while frizzled 4 (Fzd4) mRNA declined on day 5 and increased from day 10 to day 20 after implantation in hyperlipidemia rats than in normal rats. Next, BMSCs were cultured under HF or normal medium in vitro. In the HF group, ALP activity and mineralization, ALP and Runx2 mRNAs and proteins expression, and miR-29a-3p expression were suppressed, while adipogenesis was increased, as a result, cytoskeletons were sparse and disordered compared to control group. However, when miR-29a-3p was overexpressed in BMSCs, ALP activity, ALP, Runx2, Dvl2 and Fzd4 mRNAs and proteins expressions were up-regulated. As miR-29a-3p was inhibited in BMSCs, the reverse results were obtained. In addition, promoter assay revealed that miR-29a-3p can directly suppress Wnt/ß-catenin pathway related Dvl2 and Fzd4 through binding to their 3'-UTR. CONCLUSIONS: MiR-29a-3p facilitated implant osseointegration via targeting Wnt/ß-catenin pathway-related Dvl2 and Fzd4. MiR-29a-3p/Dvl2/Fzd4 may serve as a promising therapeutic target for hyperlipidemia osseointegration.

6.
J Dent Anesth Pain Med ; 18(3): 129-142, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29984317

RESUMO

INTRODUCTION: This systematic review evaluated the use of buffered versus non-buffered lidocaine to increase the efficacy of inferior alveolar nerve block (IANB). MATERIALS AND METHODS: Randomized, double-blinded studies from PubMed, Web of Science, Cochrane Library, Embase, and ProQuest were identified. Two of the authors assessed the studies for risk of bias. Outcomes included onset time, injection pain on a visual analog scale (VAS), percentage of painless injections, and anesthetic success rate of IANB. RESULTS: The search strategy yielded 19 references. Eleven could be included in meta-analyses. Risk of bias was unclear in ten and high in one study. Buffered lidocaine showed 48 seconds faster onset time (95% confidence interval [CI], -42.06 to -54.40; P < 0.001) and 5.0 units lower (on a scale 0-100) VAS injection pain (95% CI, -9.13 to -0.77; P=0.02) than non-buffered. No significant difference was found on percentage of people with painless injection (P = 0.059), nor success rate (P = 0.290). CONCLUSION: Buffered lidocaine significantly decreased onset time and injection pain (VAS) compared with non-buffered lidocaine in IANB. However due to statistical heterogeneity and low sample size, quality of the evidence was low to moderate, additional studies with larger numbers of participants and low risk of bias are needed to confirm these results.

7.
J Oral Implantol ; 2018 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-29303416

RESUMO

The aim was to investigate the osseointegration of a novel coating-plasma-sprayed nanostructured zirconia (NSZ) in dental implant. Nanostructured zirconia coating on non-thread titanium implant was prepared by plasma spraying, the implant surface morphology, surface roughness and wettability were measured. In vivo, nanostructured zirconia-coated implants were inserted in rabbit tibia and animals were respectively sacrificed at 2, 4, 8 and 12 weeks after implantation. The bond strength between implant and bone was measured by removal torque (RTQ) test. The osseointegration was observed by scanning electron microscopy (SEM), micro computed tomography (Micro CT) and histological analyses. Quantified parameters were calculated, including removal torque, Bone Volume to Tissue Volume (BV/TV), Trabecular Thickness (Tb. Th), Trabecular Number (Tb. N), Trabecular Separation/Spacing (Tb. Sp), and Bone-Implant contact (BIC) percentage. The statistical differences were detected by two-tail Mann-Whitney U test (SPSS 20.0). The surface roughness (1.58µm) and wettability (54.61°) of nanostructured zirconia coated implant was more suitable than those of titanium implant (0.598µm and 74.38°) for osseointegration and hierarchical surface morphology could be seen on zirconia coating. The histological analyses showed that zirconia coated implant induced earlier and more condensed bone formation than titanium implant at 2 and 4 weeks. Quantified parameters showed the significant differences between these two groups at early healing period, but the differences between these two groups decreased with the increase of healing period. All these results demonstrated that plasma sprayed zirconia coated implant induced better bone formation than titanium implant at early stage.

8.
Calcif Tissue Int ; 101(5): 457-464, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28795233

RESUMO

Amelogenesis (tooth enamel formation) is a biomineralization process consisting primarily of two stages (secretory stage and maturation stage) with unique features. During the secretory stage, the inner epithelium of the enamel organ (i.e., the ameloblast cells) synthesizes and secretes enamel matrix proteins (EMPs) into the enamel space. The protein-rich enamel matrix forms a highly organized architecture in a pH-neutral microenvironment. As amelogenesis transitions to maturation stage, EMPs are degraded and internalized by ameloblasts through endosomal-lysosomal pathways. Enamel crystallite formation is initiated early in the secretory stage, however, during maturation stage the more rapid deposition of calcium and phosphate into the enamel space results in a rapid expansion of crystallite length and mineral volume. During maturation-stage amelogenesis, the pH value of enamel varies considerably from slightly above neutral to acidic. Extracellular acid-base balance during enamel maturation is tightly controlled by ameloblast-mediated regulatory networks, which include significant synthesis and movement of bicarbonate ions from both the enamel papillary layer cells and ameloblasts. In this review we summarize the carbonic anhydrases and the carbonate transporters/exchangers involved in pH regulation in maturation-stage amelogenesis. Proteins that have been shown to be instrumental in this process include CA2, CA6, CFTR, AE2, NBCe1, SLC26A1/SAT1, SLC26A3/DRA, SLC26A4/PDS, SLC26A6/PAT1, and SLC26A7/SUT2. In addition, we discuss the association of miRNA regulation with bicarbonate transport in tooth enamel formation.


Assuntos
Amelogênese , Bicarbonatos/metabolismo , Esmalte Dentário/metabolismo , Animais , Proteínas de Transporte de Ânions/metabolismo , Transporte Biológico , Anidrases Carbônicas/metabolismo , Antiportadores de Cloreto-Bicarbonato/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Esmalte Dentário/crescimento & desenvolvimento , Humanos , MicroRNAs/metabolismo , Simportadores de Sódio-Bicarbonato/metabolismo
9.
Front Physiol ; 8: 307, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28559854

RESUMO

Amelogenesis features two major developmental stages-secretory and maturation. During maturation stage, hydroxyapatite deposition and matrix turnover require delicate pH regulatory mechanisms mediated by multiple ion transporters. Several members of the Slc26 gene family (Slc26a1, Slc26a3, Slc26a4, Slc26a6, and Slc26a7), which exhibit bicarbonate transport activities, have been suggested by previous studies to be involved in maturation-stage amelogenesis, especially the key process of pH regulation. However, details regarding the functional role of these genes in enamel formation are yet to be clarified, as none of the separate mutant animal lines demonstrates any discernible enamel defects. Continuing with our previous investigation of Slc26a1-/- and Slc26a7-/- animal models, we generated a double-mutant animal line with the absence of both Slc26a1 and Slc26a7. We showed in the present study that the double-mutant enamel density was significantly lower in the regions that represent late maturation-, maturation- and secretory-stage enamel development in wild-type mandibular incisors. However, the "maturation" and "secretory" enamel microstructures in double-mutant animals resembled those observed in wild-type secretory and/or pre-secretory stages. Elemental composition analysis revealed a lack of mineral deposition and an accumulation of carbon and chloride in double-mutant enamel. Deletion of Slc26a1 and Slc26a7 did not affect the stage-specific morphology of the enamel organ. Finally, compensatory expression of pH regulator genes and ion transporters was detected in maturation-stage enamel organs of double-mutant animals when compared to wild-type. Combined with the findings from our previous study, these data indicate the involvement of SLC26A1and SLC26A7 as key ion transporters in the pH regulatory network during enamel maturation.

10.
Front Physiol ; 8: 336, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28588505

RESUMO

Calcium export is a key function for the enamel organ during all stages of amelogenesis. Expression of a number of ATPase calcium transporting, plasma membrane genes (ATP2B1-4/PMCA1-4), solute carrier SLC8A genes (sodium/calcium exchanger or NCX1-3), and SLC24A gene family members (sodium/potassium/calcium exchanger or NCKX1-6) have been investigated in the developing enamel organ in earlier studies. This paper reviews the calcium export pathways that have been described and adds novel insights to the spatiotemporal expression patterns of PMCA1, PMCA4, and NCKX3 during amelogenesis. New data are presented to show the mRNA expression profiles for the four Atp2b1-4 gene family members (PMCA1-4) in secretory-stage and maturation-stage rat enamel organs. These data are compared to expression profiles for all Slc8a and Slc24a gene family members. PMCA1, PMCA4, and NCKX3 immunolocalization data is also presented. Gene expression profiles quantitated by real time PCR show that: (1) PMCA1, 3, and 4, and NCKX3 are most highly expressed during secretory-stage amelogenesis; (2) NCX1 and 3, and NCKX6 are expressed during secretory and maturation stages; (3) NCKX4 is most highly expressed during maturation-stage amelogenesis; and (4) expression levels of PMCA2, NCX2, NCKX1, NCKX2, and NCKX5 are negligible throughout amelogenesis. In the enamel organ PMCA1 localizes to the basolateral membrane of both secretory and maturation ameloblasts; PMCA4 expression is seen in the basolateral membrane of secretory and maturation ameloblasts, and also cells of the stratum intermedium and papillary layer; while NCKX3 expression is limited to Tomes' processes, and the apical membrane of maturation-stage ameloblasts. These new findings are discussed in the perspective of data already present in the literature, and highlight the multiplicity of calcium export systems in the enamel organ needed to regulate biomineralization.

11.
Sci Rep ; 7: 44118, 2017 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-28287144

RESUMO

Amelogenesis imperfecta (AI) is group of inherited disorders resulting in enamel pathologies. The involvement of epigenetic regulation in the pathogenesis of AI is yet to be clarified due to a lack of knowledge about amelogenesis. Our previous genome-wide microRNA and mRNA transcriptome analyses suggest a key role for miR-153 in endosome/lysosome-related pathways during amelogenesis. Here we show that miR-153 is significantly downregulated in maturation ameloblasts compared with secretory ameloblasts. Within ameloblast-like cells, upregulation of miR-153 results in the downregulation of its predicted targets including Cltc, Lamp1, Clcn4 and Slc4a4, and a number of miRNAs implicated in endocytotic pathways. Luciferase reporter assays confirmed the predicted interactions between miR-153 and the 3'-UTRs of Cltc, Lamp1 (in a prior study), Clcn4 and Slc4a4. In an enamel protein intake assay, enamel cells transfected with miR-153 show a decreased ability to endocytose enamel proteins. Finally, microinjection of miR-153 in the region of mouse first mandibular molar at postnatal day 8 (PN8) induced AI-like pathologies when the enamel development reached maturity (PN12). In conclusion, miR-153 regulates maturation-stage amelogenesis by targeting key genes involved in the endocytotic and endosomal/lysosomal pathways, and disruption of miR-153 expression is a potential candidate etiologic factor contributing to the occurrence of AI.


Assuntos
Amelogênese Imperfeita/metabolismo , Amelogênese , Esmalte Dentário/crescimento & desenvolvimento , Esmalte Dentário/metabolismo , Endocitose , MicroRNAs/metabolismo , Ameloblastos/metabolismo , Amelogênese Imperfeita/etiologia , Animais , Células Cultivadas , Esmalte Dentário/patologia , Proteínas do Esmalte Dentário/metabolismo , Endossomos/metabolismo , Lisossomos/metabolismo , Masculino , Camundongos Endogâmicos BALB C
12.
PLoS One ; 10(12): e0144703, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26671068

RESUMO

The bicarbonate transport activities of Slc26a1, Slc26a6 and Slc26a7 are essential to physiological processes in multiple organs. Although mutations of Slc26a1, Slc26a6 and Slc26a7 have not been linked to any human diseases, disruption of Slc26a1, Slc26a6 or Slc26a7 expression in animals causes severe dysregulation of acid-base balance and disorder of anion homeostasis. Amelogenesis, especially the enamel formation during maturation stage, requires complex pH regulation mechanisms based on ion transport. The disruption of stage-specific ion transporters frequently results in enamel pathosis in animals. Here we present evidence that Slc26a1, Slc26a6 and Slc26a7 are highly expressed in rodent incisor ameloblasts during maturation-stage tooth development. In maturation-stage ameloblasts, Slc26a1, Slc26a6 and Slc26a7 show a similar cellular distribution as the cystic fibrosis transmembrane conductance regulator (Cftr) to the apical region of cytoplasmic membrane, and the distribution of Slc26a7 is also seen in the cytoplasmic/subapical region, presumably on the lysosomal membrane. We have also examined Slc26a1 and Slc26a7 null mice, and although no overt abnormal enamel phenotypes were observed in Slc26a1-/- or Slc26a7-/- animals, absence of Slc26a1 or Slc26a7 results in up-regulation of Cftr, Ca2, Slc4a4, Slc4a9 and Slc26a9, all of which are involved in pH homeostasis, indicating that this might be a compensatory mechanism used by ameloblasts cells in the absence of Slc26 genes. Together, our data show that Slc26a1, Slc26a6 and Slc26a7 are novel participants in the extracellular transport of bicarbonate during enamel maturation, and that their functional roles may be achieved by forming interaction units with Cftr.


Assuntos
Proteínas de Transporte de Ânions/genética , Esmalte Dentário/crescimento & desenvolvimento , Família Multigênica , Ameloblastos/metabolismo , Amelogênese/genética , Animais , Proteínas de Transporte de Ânions/metabolismo , Western Blotting , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Esmalte Dentário/metabolismo , Esmalte Dentário/ultraestrutura , Dentina/metabolismo , Regulação para Baixo/genética , Perfilação da Expressão Gênica , Concentração de Íons de Hidrogênio , Mandíbula/diagnóstico por imagem , Camundongos , Fenótipo , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Espectrometria por Raios X , Regulação para Cima/genética , Microtomografia por Raio-X
13.
BMC Genomics ; 15: 998, 2014 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-25406666

RESUMO

BACKGROUND: In the rodent incisor during amelogenesis, as ameloblast cells transition from secretory stage to maturation stage, their morphology and transcriptome profiles change dramatically. Prior whole genome transcriptome analysis has given a broad picture of the molecular activities dominating both stages of amelogenesis, but this type of analysis has not included miRNA transcript profiling. In this study, we set out to document which miRNAs and corresponding target genes change significantly as ameloblasts transition from secretory- to maturation-stage amelogenesis. RESULTS: Total RNA samples from both secretory- and maturation-stage rat enamel organs were subjected to genome-wide miRNA and mRNA transcript profiling. We identified 59 miRNAs that were differentially expressed at the maturation stage relative to the secretory stage of enamel development (False Discovery Rate (FDR)<0.05, fold change (FC)≥1.8). In parallel, transcriptome profiling experiments identified 1,729 mRNA transcripts that were differentially expressed in the maturation stage compared to the secretory stage (FDR<0.05, FC≥1.8). Based on bioinformatics analyses, 5.8% (629 total) of these differentially expressed genes (DEGS) were highlighted as being the potential targets of 59 miRNAs that were differentially expressed in the opposite direction, in the same tissue samples. Although the number of predicted target DEGs was not higher than baseline expectations generated by examination of stably expressed miRNAs, Gene Ontology (GO) analysis showed that these 629 DEGS were enriched for ion transport, pH regulation, calcium handling, endocytotic, and apoptotic activities. Seven differentially expressed miRNAs (miR-21, miR-31, miR-488, miR-153, miR-135b, miR-135a and miR298) in secretory- and/or maturation-stage enamel organs were confirmed by in situ hybridization. Further, we used luciferase reporter assays to provide evidence that two of these differentially expressed miRNAs, miR-153 and miR-31, are potential regulators for their predicated target mRNAs, Lamp1 (miR-153) and Tfrc (miR-31). CONCLUSIONS: In conclusion, these data indicate that miRNAs exhibit a dynamic expression pattern during the transition from secretory-stage to maturation-stage tooth enamel formation. Although they represent only one of numerous mechanisms influencing gene activities, miRNAs specific to the maturation stage could be involved in regulating several key processes of enamel maturation by influencing mRNA stability and translation.


Assuntos
Amelogênese/genética , Genoma , MicroRNAs/genética , Transcriptoma/genética , Animais , Análise por Conglomerados , Esmalte Dentário/crescimento & desenvolvimento , Esmalte Dentário/metabolismo , Regulação para Baixo/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Ontologia Genética , Redes Reguladoras de Genes , Hibridização In Situ , Proteínas de Membrana Lisossomal/genética , Proteínas de Membrana Lisossomal/metabolismo , Masculino , MicroRNAs/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Reprodutibilidade dos Testes , Regulação para Cima/genética
14.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 30(3): 296-8, 303, 2012 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-22768771

RESUMO

OBJECTIVE: To establish the three-dimensional model of human permanent premolars based on Micro-computed tomography (Micro-CT) data, and evaluate the efficiency quantitatively of two different instrumentations for root canal retreatment. METHODS: Forty extracted permanent premolars for the reason of orthodontic treatment were collected, prepared by using ProTaper Ni-Ti files and filled by cold gutta pertscha lateral condensation technique. The subjects were scanned by Micro-CT. Forty teeth were randomly divided into two groups and retreated by K-Flexo files and ProTaper Universal retreatment system respectively. Then all subjects were scanned again, and the mean percentage of remaining filling materials and the scores of remaining filling materials presented in upper, middle and apical 1/3 of the canal were calculated. RESULTS: Mean percentage of the remaining filling materials by K-Flexo files was lower than that by ProTaper Universal retreatment system (P=0.005). The scores demonstrated that K-Flexo files had greater efficiency than ProTaper Universal retreatment system when retreating the apical 1/3 of canal (P<0.05). CONCLUSION: This study shows that both techniques could not remove filling materials completely.


Assuntos
Guta-Percha , Preparo de Canal Radicular , Ligas Dentárias , Cavidade Pulpar , Humanos , Níquel , Retratamento , Materiais Restauradores do Canal Radicular , Tratamento do Canal Radicular , Titânio , Microtomografia por Raio-X
15.
Clin Oral Implants Res ; 23(7): 846-52, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21564304

RESUMO

OBJECTIVE: The study was designed to evaluate the comparative effect of osseointegration induced by the dental implants of Beijing Leiden Biomaterial (BLB) and BLBIII. MATERIALS AND METHODS: The surface properties ofBLBI and BLBIII were studied through thermal field-scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDS) and optical profilometer. A total of 36 BLBI and BLBIII implants, with each of the two groups possessing 18, were randomly implanted into the extraction fossa of the mandibular premolar areas of six Beagles. The animals were then executed 2, 4 and 8 weeks after the surgery, which was followed by macroscopic examination and histomorphometric analysis. RESULTS: Typical cloud-form microstructure was found on the surface of BLBI implant, which was distributed widely yet in an irregular way. The surface of BLBIII implant was mainly featured by a highly porous layer. The EDS spectra of BLBI indicated the peaks of calcium (Ca) and phosphorous (P) compatible with apatite phase, while the peaks of Ca, P, oxygen and titanium were incorporated in the BLBIII group. The ratio of Ca and K showed no significant differences in the surface chemical composition of BLBI and BLBIII. Surface microtopographic analysis showed a statistical difference (P<0.01) in the roughness between BLBI (R(a)) and BLBIII. In the healing period, a larger amount of osteoid and bone tissues were observed in the areas surrounding the BLBIII group than those of the BLBII group. After 2 and 4 weeks of the surgery, the bone-implant contact (BIC) of BLBIII group presented higher value of statistical significance (P<0.05) than that of BLBI. However, after the 8-week healing period, the BIC difference between the two groups proved to be of no statistical significance (P>0.05). CONCLUSION: Micro-arc oxidation (MAO) and electrophoresis deposition (EPD) are able to produce a highly porous layer on the surface of BLBIII, which is characterized by a relatively stable Ca/P ratio similar to that of the hydroxyapatite layer. Therefore, superior and early osseointegration potential was demonstrated in the threaded implants treated by MAO coupling with EPD, rather than the merely cylindrical-shaped ones with plasma-sprayed HA coating layer.


Assuntos
Implantação Dentária Endóssea/métodos , Implantes Dentários , Osseointegração , Animais , Materiais Revestidos Biocompatíveis/química , Planejamento de Prótese Dentária , Cães , Imageamento Tridimensional , Implantes Experimentais , Masculino , Mandíbula/cirurgia , Microscopia Eletrônica de Varredura , Espectrometria por Raios X , Estatísticas não Paramétricas , Propriedades de Superfície , Titânio/química
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