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1.
Chinese Journal of Rehabilitation Theory and Practice ; (12): 364-367, 2023.
Article in Chinese | WPRIM | ID: wpr-971880

ABSTRACT

ObjectiveTo clarify the feasibility of the 3D scanning volume method for distal upper limb volume measurement, and to analyze its scorer reliability and criterion-related validity. MethodsFrom January to March, 2022, a therapist (operator A) who had not been exposed to 3D scanning volume method and water displacement method was trained to use a handheld 3D laser scanner and a spilt cup to measure the volume of a PVC distal upper limb model. The operation time of 30 operations of each method was recorded. The learning curves of the two methods were plotted using cumulative sum (CUSUM) analysis. The curve was cut into the learning stage and the mastery stage by the vertex of peak. The times required to reach the mastery stage and the operation time of the mastery stage for the two methods were recorded. A total of 20 healthy subjects were recruited from Huashan Hospital of Fudan University. Two trained therapists (operator A and operator B) measured the bilateral distal upper limb volume using a handheld 3D laser scanner, and operator A measured the bilateral distal upper limb volume using a spilt cup. ResultsThe fitting learning curve of the 3D scanning volume method (R² = 0.984) reached its peak after eight times of operation; while that of the water displacement method (R² = 0.494) reached its peak after five times of operation. At mastery stage, the operator spent less time using 3D scanning volume method than using water displacement method (P < 0.05). The intraclass correlation coefficient between the two operators were both 0.979 for bilateral distal upper limb volume measure (P < 0.001). The Pearson coefficients was above 0.979 between 3D scanning volume method and water displacement method (P < 0.001). ConclusionA therapist can master the use of the 3D scanning volume method after eight times of operation, and the operation time of 3D scanning volume method is shorter than that of water displacement method at mastery stage. The 3D scanning volume method is well reliable and valid, that can be used as an alternative to the water displacement method for distal upper limb volumetric measurement.

2.
International Journal of Oral Science ; (4): 17-17, 2022.
Article in English | WPRIM | ID: wpr-929145

ABSTRACT

Dental Caries is a kind of chronic oral disease that greatly threaten human being's health. Though dentists and researchers struggled for decades to combat this oral disease, the incidence and prevalence of dental caries remain quite high. Therefore, improving the disease management is a key issue for the whole population and life cycle management of dental caries. So clinical difficulty assessment system of caries prevention and management is established based on dental caries diagnosis and classification. Dentists should perform oral examination and establish dental records at each visit. When treatment plan is made on the base of caries risk assessment and carious lesion activity, we need to work out patient‑centered and personalized treatment planning to regain oral microecological balance, to control caries progression and to restore the structure and function of the carious teeth. And the follow-up visits are made based on personalized caries management. This expert consensus mainly discusses caries risk assessment, caries treatment difficulty assessment and dental caries treatment plan, which are the most important parts of caries management in the whole life cycle.


Subject(s)
Humans , Consensus , Dental Care , Dental Caries/prevention & control , Prevalence
3.
Chinese Journal of Medical Education Research ; (12): 1160-1164, 2021.
Article in Chinese | WPRIM | ID: wpr-908977

ABSTRACT

Objective:To explore the application of the Simodont dental trainer in preclinical manual dexterity training for dental students of different grades, and to discuss its effect by quantitatively evaluating their practice results.Methods:The evaluation was conducted among 118 students in the Department of Stomatology, Shantou University Medical College from Batch 2015 to Batch 2018. Each student had five different manual dexterity modules for training. Each module had three levels of difficulty and was required to be completed in 30 minutes. The assessment index included Target, Leeway Bottom and Sides, Container Bottom and Sides, which was provided by the Simodont dental trainer. The operating time (in seconds), the displacement of the dental hand pieces and the dental mirrors (in meters) were simultaneously recorded. SPSS 25.0 was used for statistical analysis.Results:For the index Target, Leeway Bottom and Sides, Container Bottom and Sides, the results showed that there was a statistical difference between students who passed pre-clinical training and who did not take the professional course ( P < 0.001). For the index Target, differences were showed among students from different grades in all modules ( P < 0.001). Conclusion:The circle module, channel module, hollow-circle module and cross-module in the Simodont dental trainer have sensitivity to discriminate the manual dexterity of different levels of dental students. The further assessment of the discrimination of the manual dexterity is required for assume-block module. The Simodont dental trainer can quantitatively measure the manual dexterity of dental students, which is important for the quantitative evaluation of dental preclinical education.

4.
Chinese Journal of Stomatology ; (12): 577-583, 2019.
Article in Chinese | WPRIM | ID: wpr-797544

ABSTRACT

There are several trends in contemporary endodontics such as development of minimally invasive biologically based therapies, preservation of dental pulp in a healthy status with sustained vitality, prevention of apical periodontitis and improvement of long-term survival rates of teeth with pulpal disorders. As for the vital pulp therapy, direct pulp capping is a less invasive approach to keep the exposed dental pulp intact, which may improve the long-term treatment outcome employing a minimally invasive biologically strategy. With the recent progress in pulp biology, improvement of treatment modality and development of bioactive dental cements, great advancements have been achieved in direct pulp capping therapy. This review article focuses on the transition of indications, prognostic factors and future perspectives of direct pulp capping therapy, attempting to provide evidence and practical guidance for minimally invasive biologically based therapies of teeth with injured pulp.

5.
Chinese Journal of Stomatology ; (12): 361-366, 2018.
Article in Chinese | WPRIM | ID: wpr-806627

ABSTRACT

Recently, various levels of success have been achieved in dental pulp and dentin regeneration using latest techniques such as pulp revascularization, stem cell transplantation and cell homing. These cutting-edge technologies utilize stem cell mobilization, homing and directional differentiation, stem cell sub-population isolation, expansion and transplantation, modification and optimization of biomaterials and/or synergetic effects of biological cues. The objective of this review is to identify approaches for clinical translation and improve the success rates of pulp regeneration. We will focus on either basic and clinical research progress of dental pulp revascularization, or translational challenges and strategies of stem cell transplantation and cell homing in dental pulp regeneration.

6.
Chinese Journal of Stomatology ; (12): 432-438, 2017.
Article in Chinese | WPRIM | ID: wpr-808970

ABSTRACT

Objective@#To examine the expression of naked cuticle homolog 2 (Nkd2) in the process of root development and osteogenic differentiation of dental follicle cells of rat (rDFC), in order to explore the molecular mechanisms of Nkd2 on the osteoblast differentiation of rDFCs.@*Methods@#Immunohistochemical analysis was used to detect the expression of Nkd2 in the base dental follicle of the mandibular first molar of rat at 1, 3, 5, 7, 9, 11 and 13 days postnatal. Mineralization nodule formation of rDFCs was detected by alizarin red staining and cetylpyridine. The change of Nkd2 during osteogenic differentiation of rDFCs was evaluated by Western blotting and the associations between Nkd2 and osteogenic cytokines of alkaline phosphatase (ALP), Runt-related transcription factor-2 (RUNX2) and osteocalcin (OCN) were examined. The rDFCs were transfected with small interfering RNA (siRNA) to knock down the expression of Nkd2 and Western blotting and quantitative real-time PCR (qPCR) were adopted to explore the effects of Nkd2 on osteogenic differentiation by detecting variations of Nkd2 and osteogenic factors ALP, RUNX2, OCN among silencing group (Si), negative control RNA group (Nc) and mock control group (Mock), respectively.@*Results@#The expression of Nkd2 in the base dental follicle of the mandibular first molar of rat was time dependent. Mineralization nodules of rDFCs and absorbance of cetylpyridine after osteogenic induction increased gradually (the absorbances of cetylpyridine were 0 week: 0.017±0.005, 1 week: 0.702±0.044, 2 weeks: 1.812±0.531, 3 weeks: 2.767±0.253, respectively). Results of Western blotting showed that Nkd2 (1.60±0.23) of mineralization group was significantly higher than that of control group (1) (P<0.05) at the early stage of osteogenic differentiation along with the expression of other osteogenic factors. The protein and mRNA of Nkd2 and osteogenic factors were significantly decreased in Si group compared with Nc and Mock groups (P<0.05), and no changes between Nc and Mock groups were observed. The changes of protein in Si, Nc and Mock groups were Nkd2: 0.42±0.10, 1.12±0.07, 1, ALP: 0.70±0.15, 1.11±0.14, 1, RUNX2: 0.58±0.08, 0.93±0.08, 1 and OCN: 0.64±0.06, 0.99±0.02, 1, respectively. The mRNA variances in Si, Nc and Mock groups were Nkd2: 0.39±0.05, 0.96±0.10, 1, ALP: 0.15±0.13, 1.01±0.07, 1, RUNX2: 0.39±0.31, 0.97±0.13, 1, OCN: 0.17±0.08, 1.08±0.21, 1, respectively.@*Conclusions@#Nkd2 participates in the root development process in rat and may acts as a positive role in the early stage of osteogenic differentiation of rDFCs in rat.

7.
West China Journal of Stomatology ; (6): 1-7, 2017.
Article in Chinese | WPRIM | ID: wpr-309083

ABSTRACT

Dental caries is a major disease that threaten human's oral healthy severely with the characteristics of high incidence, low rate of treatment and high rate of retreatment. At present, restorative treatment remains the main method for caries treatment. With the development of the Minimally Invasive Cosmetic Dentistry (MICD), reasonable application of various treatment technologies, maximum preservation of tooth tissues and realizing the maximization of treatment effects become problems that call for immediate solution in dental clinics. In addition, there still exist a large number of old restorations that need standard retreatments. Here, some difficulty influence factors of dental caries clinical treatment such as systemic and oral factors, individual caries susceptibility, treatment technologies and materials, retreatment methods of old restorations and technique sensitivity are analyzed, and corresponding processing strategies are also put forward.


Subject(s)
Humans , Dental Caries , Dental Caries Susceptibility , Retreatment
8.
Chinese Journal of Stomatology ; (12): 672-676, 2014.
Article in Chinese | WPRIM | ID: wpr-360473

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the sealing properties of three resin- based sealers, EndoREZ, RealSEAL and RealSEAL SE.</p><p><b>METHODS</b>Forthy-eight extracted human anterior teeth with single root and canal were prepared using ProTaper files with crown-down technique to F3. The teeth were filled with three sealer respectively with hot gutta- percha vertical condensation technique simulating the clinical situation. Leakage quantity was detected using computerized fluid filtration meter with 10 samples in each group. The cross section morphology of apical parts of roots of 5 mm was observed with scanning electron microscope and transmission electron microscope in 3 samples of each group, respectively.</p><p><b>RESULTS</b>The leakage quantity of EndoREZ, RealSEAL and RealSEAL SE were (2.61±0.60), (1.43±0.11) and (1.76±0.18) µl/min, respectively. The gaps between the the sealer and the canal wall were increased in in order of RealSEAL, RealSEAL SE and EndoREZ. No obvious demineralized dentin under EndoREZ and the smear layer was not completed removed. The partly demineralized dentin was observed under RealSEAL and the smear layer was totally removed. The partly demineralized dentin was seen under RealSEAL SE and the majority of smear layer was removed.</p><p><b>CONCLUSIONS</b>Among the three resin- based sealers, RealSEAL has the best sealing properties, followed by RealSEAL SE and EndoREZ.</p>


Subject(s)
Humans , Composite Resins , Dental Leakage , Dentin , Epoxy Resins , Gutta-Percha , Pit and Fissure Sealants , Root Canal Filling Materials , Tooth , Tooth Root
9.
Chinese Journal of Stomatology ; (12): 224-228, 2014.
Article in Chinese | WPRIM | ID: wpr-260850

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the functions of sodium tripolyphosphate (STTP) and polyacrylic acid (PAA) in the process of collagen biomimetic mineralization. This would allow future applications to other collagen matrices such as bone collagen or 3-D collagen scaffolds.</p><p><b>METHODS</b>Glass cover slips and transmission electron microscopy (TEM) grids were coated with reconstituted typeIcollagen fibrils. Mineralization of the reconstituted collagens was demonstrated with scanning electron microscopy (SEM) and TEM using a Portland cement-containing resin composite and a phosphate-containing fluid in the presence of PAA and STTP. The rest were immersed in a biomimetic remineralization medium without PAA and/or STTP (control).</p><p><b>RESULTS</b>In the presence of PAA and STTP in the mineralization medium, intrafibrillar mineralization based on the non-classical crystallisation pathway could be identified. Mineral phases were evident within the collagen fibrils as early as 12 h after the initially-formed amorphous calcium phosphate nanoprecursors were transformed into apatite nanocrystals. Collagens at 72 h were heavily mineralized with periodically arranged intrafibrillar apatite platelets. Conversely, only large mineral spheres with no preferred association with collagen fibrils were observed in the absence of biomimetic analogues in the medium (control).</p><p><b>CONCLUSIONS</b>Intrafibrillar apatite deposition can be achieved via biomimetic mineralization system containing PAA and STTP when amorphous calcium phosphate precursor is stabilized.</p>


Subject(s)
Humans , Acrylic Resins , Chemistry , Apatites , Biomimetics , Bone and Bones , Calcium Phosphates , Collagen , Collagen Type I , Chemistry , Composite Resins , Microscopy, Electron, Transmission , Minerals , Phosphates , Polyphosphates , Chemistry , Tissue Scaffolds
10.
Chinese Journal of Stomatology ; (12): 284-289, 2014.
Article in Chinese | WPRIM | ID: wpr-260838

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the differential expression profile and bioinformatic analysis of microRNA (miRNA) in human dental pulp cells (DPC) during endothelial differentiation.</p><p><b>METHODS</b>DPC were cultured in endothelial induction medium (50 µg/L vascular endothelial growth factor, 10 µg/L basic fibroblast growth factor and 2% fetal calf serum) for 7 days. Meanwhile non-induced DPC were used as control.Quantitative real-time PCR (qRT-PCR) was applied to detect vascular endothelial marker genes [CD31, von Willebrand factor (vWF) and vascular endothelial-cadherin (VE-cadherin)] and in vitro tube formation on matrigel was used to analyze the angiogenic ability of differentiated cells. And then miRNA expression profiles of DPC were examined using miRNA microarray and then the differentially expressed miRNA were validated by qRT-PCR. Furthermore, bioinformatic analysis was employed to predict the target genes of miRNA and to analyze the possible biological functions and signaling pathways that were involved in DPC after induction.</p><p><b>RESULTS</b>The relative mRNA level of CD31, vWF and VE-cadherin in the control group were (3.48 ± 0.22) ×10(-4), (3.13 ± 0.31) ×10(-4) and (39.60 ± 2.36) ×10(-4), and (19.57 ± 2.20) ×10(-4), (48.13 ± 0.54) ×10(-4) and (228.00 ± 8.89) ×10(-4) in the induced group. The expressions of CD31, vWF and VE-cadherin were increased significantly in endothelial induced DPC compared to the control group (P < 0.05). For in vitro tube formation assay, tubular structures were formed on the matrigel by differentiated DPC. A total of 47 miRNA were differentially expressed, in which 15 miRNA were up-regulated and 32 miRNAs down-regulated in differentiated DPC compared with the control. Of these, 4 miRNA were confirmed by qRT-PCR. The target genes of differential miRNA were predicted to associate with several biological functions, such as the regulation of transcription, cell motion, blood vessel morphogenesis, angiogenesis and cytoskeletal protein, and signaling pathways including the mitogen-activated protein kinase (MAPK) and the Wnt signaling pathway.</p><p><b>CONCLUSIONS</b>The differential miRNA expression identified in this study may be involved in governing DPC endothelial differentiation, thus contributing to the future research on regulatory mechanisms in dental pulp angiogenesis.</p>


Subject(s)
Humans , Antigens, CD , Cadherins , Cell Differentiation , Collagen , Computational Biology , Dental Pulp , Metabolism , Drug Combinations , Fibroblast Growth Factor 2 , Laminin , MicroRNAs , Platelet Endothelial Cell Adhesion Molecule-1 , Proteoglycans , RNA, Messenger , Real-Time Polymerase Chain Reaction , Signal Transduction , Vascular Endothelial Growth Factor A , Wnt Signaling Pathway , von Willebrand Factor
11.
West China Journal of Stomatology ; (6): 221-224, 2013.
Article in Chinese | WPRIM | ID: wpr-336353

ABSTRACT

Successful endodontic treatment depends on the effectiveness of the cleaning and shaping of the root canal system. Due to the complexity of the structure of root canal system and the particularity of root canal infections, the equipment and technology currently available for root canal preparation hinder the ability to adequately clean and shape the root canal system. In this review, we summarized the difficulties in the control of root canal infection, the new concept of three-dimensional root canal preparation, and its quality control and assessment.


Subject(s)
Dental Pulp Cavity , Root Canal Preparation , Root Canal Therapy
12.
Chinese Journal of Medical Aesthetics and Cosmetology ; (6): 94-96, 2012.
Article in Chinese | WPRIM | ID: wpr-428627

ABSTRACT

ObjectiveTo analyze the relationship between the patients' psychological factors and esthetics satisfaction of all-ceramic restoration of anterior teeth.MethodsThe N scales of Eysenck personality questionnaires (EPQ) were filled at the first visit,and the total scores of N scales were calculated.After restorative treatments,the satisfaction questionnaire was used to evaluate the patients' aesthetic satisfaction on material quality,color,geometry,profile,self-confidence,etc,and to analyze the relation between psychological factors and satisfaction of the patients.ResultsThe scores of EPQ N scale of the patients in this study were as follows:Nmax=23,Nmin =3,Navg =9.35±5.714.The patients had high satisfaction with restoration.Aesthetic satisfaction,color and self-confidence were in relation to the N scales scores,satisfaction of color was in relation to sickness suspicion,satisfaction of profile was in relation to enthrallment extent and guilty consciousness,and satisfaction of self-confidence improvement was in relation to anxiety and self-determination.Conclusions The psychologic factor of the patients has some influence on the esthetics satisfaction of all-ceramic restoration of anterior teeth.

13.
Chinese Journal of Microbiology and Immunology ; (12): 162-165, 2008.
Article in Chinese | WPRIM | ID: wpr-384083

ABSTRACT

Objective To examine Streptpcoccus mutans,Streptpcoccus sobrinus and Streptpcoccus sanguis in the early formation of native dental plaque biofilm. Methods An experimental dental plaque biofilm model in the oral cavity was established using enamel slabs. The spatial distribution of S. mutans, S.sobrinus and S. sanguis in the early colonization of dental plaque biofilms on the enamel surface was observed bv in situ, real-time and dynamic observations and optical sections utilizing confocal laser scanning microscopy(CLSM) and fluorescence in situ hybridization(FISH). The experiment data were analyzed with One-Way AVOVA, α=0.05 using SPSS11.5. Results Dental biofilm had a certain degree of thickness and various forms in three-dimensioned structure. The bacteria in the structure were sparse at the inner layers and the outer layers. In the middle layers the bacteria were closely compacted. There were many voids traversing from the outside of the biofilm to the enamel surface. At the initial stage of dental biofilm formation, the scanned average thickness of S. mutans,S. sobrinus and S. sanguis increased with time elapsing,the mean thicknesses of 1 h biofilms were 20.43 μm,11.50 μm and 14.76 μm,respectively,and those of 24 h were the thickest in terms of average level,the mean values were 70.25 μm,75.40 μm and 79.98 μm,respectively. Conclusion The fluorescence in situ hybridization combined with CLSM are thought to be convenient and sensitive to detect S. mutans, S. sobrinus and S. sanguis in the dental plaque biofilms.

14.
Chinese Journal of Nosocomiology ; (24)2006.
Article in Chinese | WPRIM | ID: wpr-589471

ABSTRACT

OBJECTIVE Infection control(IC) is one of the most important issues involved in the administration of modern hospitals in the world.The aim of this survey is to analyze the necessities to set up some courses on IC for undergraduates during their 5-year studying.METHODS In this study,71 academic staffs in Guanghua School of Stomatology and 74 fourth and fifth year undergraduates were surveyed by questionnaires about the necessities and knowledge of IC.RESULTS The finding showed that both academic staffs and students did not have well-educated knowledge of infection control,and they all agreed with an importance of IC course in college education system.CONCLUSIONS Setting-up an infection control course may be essential as an elemental education course in college.

15.
Chinese Journal of Medical Education Research ; (12)2003.
Article in Chinese | WPRIM | ID: wpr-624820

ABSTRACT

Harmonious relationship between medicine and patients is an important component constructing harmonious society. Bad harmonious relationship between medicine and patients and medical tangle case is increasing. The article introduced the concept and the causes of medical disputes. Clinical examples of medical disputes are analysed in department of cariology and endodontolo-gy,guanghua school of stomatology,sun yat-sen university.

16.
West China Journal of Stomatology ; (6): 270-273, 2003.
Article in Chinese | WPRIM | ID: wpr-283605

ABSTRACT

<p><b>OBJECTIVE</b>The purpose of this study is to construct plant expression plasmid containing the gene encoding chimera SBR-CT delta A1.</p><p><b>METHODS</b>The target gene fragment P2, including the gene-encoded chimera SBR-CT delta A1 (3,498-5,378 bp), was obtained by standard PCR amplification. The PCR products were ligated with pGEM-easy vector through TA clone to form plasmid pTSC. The plasmid pTSC and plasmid pPOKII were digested by restricted endonuclease BamHI and KpnI, and the digested products were extracted and purified for recombination. Then the purified P2 and plasmid pPOKII were recombined by T4 DNA ligase to form recombinant plasmid pROSC; inserting bar gene into the plasmid and form pROSB plasmid. The recombined plasmids were isolated and identified by restricted endonuclease cutting and Sanger dideoxy DNA sequencing.</p><p><b>RESULTS</b>P2 gene was linked to pPOKII plasmid and formed recombinant plasmid pROSC. The DNA sequence and orientation were corrected. And bar gene was inserted into pPOSC and form recombinant plasmid pROSB.</p><p><b>CONCLUSION</b>Plant expression vector pROSC and pROSB containing the gene encoding chimera SBR-CT delta A1, which may provide useful experiment foundation for further study on edible vaccine against caries have been successfully constructed.</p>


Subject(s)
Animals , Rabbits , Adhesins, Bacterial , Genetics , Chimera , Genetics , Cloning, Molecular , Dental Caries , Gene Transfer Techniques , Genetic Vectors , Lipoproteins , Genetics , Solanum lycopersicum , Genetics , Metabolism , Plasmids , Genetics , Recombinant Proteins , Genetics , Recombination, Genetic , Streptococcal Vaccines , Genetics , Allergy and Immunology , Streptococcus mutans , Genetics , Allergy and Immunology , Vaccines, DNA , Genetics
17.
West China Journal of Stomatology ; (6): 353-355, 2003.
Article in Chinese | WPRIM | ID: wpr-283582

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the antigenicity of the peptide vaccine HDS from Streptococcus mutans glucosyltransferase and its ability to induce protective immune responses in an experimental rat model of dental caries.</p><p><b>METHODS</b>Artificial antigen HDS-KLH, peptide HDS, glycosyltransferase were injected to immunize rats. Measurement of the specific anti-HDS, GTF IgG or IgA concentration in saliva and serum were undertaken by ELISA among the experimental groups. Gnotobiotic rat model was developed when challenged S. mutans and a caries promoting diet. The jaws of the rats were selected and dyed. The Keyes caries score for each jaw were counted.</p><p><b>RESULTS</b>The level of serum and salivary specific anti-HDS IgG and IgA in the group immunized by HDS-KLH was significantly higher than that in control group (P < 0.05). The Keyes caries score of GTF, HDS and HDS-KLH immunized group were significantly lower than that of control group, especially lower in smooth tooth surface.</p><p><b>CONCLUSION</b>Artificial antigen HDS-KLH could induce immune response. As a peptide vaccine, HDS-KLH could reduce the caries incidence in experimental rat model.</p>


Subject(s)
Animals , Male , Rats , Dental Caries , Glucosyltransferases , Genetics , Allergy and Immunology , Peptides , Allergy and Immunology , Rats, Sprague-Dawley , Streptococcal Vaccines , Allergy and Immunology , Streptococcus mutans , Genetics , Allergy and Immunology
18.
Chinese Journal of Stomatology ; (12): 333-335, 2002.
Article in English | WPRIM | ID: wpr-347383

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the shaping effects of three nickel-titanium rotary instruments on preparing curved canals in posterior teeth.</p><p><b>METHODS</b>64 curved mesial canals of extracted lower molars, embedded in the Branmante models, were randomly assigned to four groups: (1) Flexofile; (2) LightSpeed; (3) ProFile; (4) Qantec SC. Apical preparation was carried out till size 30. The area of dentine removal, least remaining dentine thickness and transportation of canal center were measured.</p><p><b>RESULTS</b>Flexofile resulted in more dentine removal and canal center transportation than LightSpeed and ProFile (P < 0.05) at the apical and mid-root levels. In the mid-root sections, Flexofile left the thinnest dental wall in the distal aspect; 87% of the canal centers in the Flexofile group were transported in a distal direction as compared with one third in other groups.</p><p><b>CONCLUSIONS</b>LightSpeed and ProFile exhibited better shaping ability than Flexofile in preparing curved canals.</p>


Subject(s)
Humans , Dental Alloys , Dental Instruments , Reference Standards , Molar , Nickel , Root Canal Preparation , Titanium
19.
Journal of Practical Stomatology ; (6)2001.
Article in Chinese | WPRIM | ID: wpr-546352

ABSTRACT

Objective:To discuss the clinical feature and treatment of second mesiobuccal canal (MB2)of permanent maxillary molars. Methods:The root canals of 106 maxillary first molars and 80 maxillary second molars were explored with small size K files. The frequency and morphology of root canals were recorded. The canals of all cases were instrumented by Ni-Ti rotary instruments Hero 642, and obturated with lateral condensation technique. The efficiency of preparation and obturation was analyzed with radiographs before and after treatment. Results:The frequency of MB2 canal in maxillary first and second molars were 82.1% and 45.0%. Most MB2 was very fine and negotiated by size 8 or 10 file combined with EDTA. No transportation, ledge, or perforation was found except that one hand file was separated. Good result of treatment was achieved in most cases. Conclusion:The incidence of MB2 canals of maxillary first molars was higher than that of second molars, and most of them were very fine. The MB2 canals can be negotiated with small size file combined with EDTA, and shaped well with Ni-Ti rotary instruments.

20.
Journal of Practical Stomatology ; (6)2001.
Article in Chinese | WPRIM | ID: wpr-544532

ABSTRACT

Objective:To investigate the effects of E.coli lipopolysaccharide(LPS) stimulus on the synthesis of TLR4 protein and its mRNA expression in human dental pulp cells(HDPCs), and to explore the roles of TLR4 on the activation of HDPCs induced by LPS. Methods:The expressions of TLR4 mRNA and the synthesis of TLR4 protein in HDPCs induced by LPS were detected by real-time fluorescence quantitative RT-PCR(FQ RT-PCR) and immunofluorescence technique.IL-1? concentrations in the supernatant of cultured HDPCs pretreated with TLR4 antibody were assayed with ELISA. Results: The expressions of TLR4 could not be detected in normal HDPCs.After being stimulated with 1?10-4 g/L LPS for 6,12 or 24 h, immunostaining showed that TLR4 was expressed in cytomembrane and cytoplasm of HDPCs,while in nucleus the expressions were negative. FQ RT-PCR showed their expressions significantly increased after being stimulated with LPS (P

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