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1.
Chinese Journal of Stomatology ; (12): 382-386, 2019.
Article in Chinese | WPRIM | ID: wpr-810646

ABSTRACT

There are significant benefits for dentists, technicians and patients through data collection and case accumulation in esthetic dentistry. In order to give a brief answer to dentists′ puzzles in daily clinical practice, this essay focused on introducing the methods to choose the correct esthetic case, the details to collect the data and the ways to do case accumulation. The esthetic diagnosis and treatment can be greatly improved and the innovation may be achieved through such data collection and case accumulation.

2.
Chinese Journal of Geriatrics ; (12): 50-54, 2019.
Article in Chinese | WPRIM | ID: wpr-734512

ABSTRACT

Objective To evaluate the influence of single nucleotide polymorphism of Wilms tumor 1(WT1)gene rs16754 on the chemosensitivity and clinical outcomes of elderly patients with acute myeloid leukemia(AML).Methods A total of 178 AML patients aged 60 years and over who received cytarabine-based chemotherapy were enrolled in this retrospective study.The peripheral blood was extracted from 178 AML patients receiving chemotherapy for DNA preparation and study.And bone marrow specimens were collected in 65 AML patients before chemotherapy.The Wilms' Tumor-1 (WT1) rs16754 polymorphism was detected by PCR-RFLP method.The association between genotypes and other variables were analyzed by using Logistic regression model.Variables were adjusted by Cox regression analysis.Results The locus of WT1 gene rs16754 is located in coding region of WT1 gene.The genotype frequency and distribution of the studied population were 55.62% (99/178)in GG,37.64%(67/178)in GA,and 6.74%(12/178)in AA,with minimum allele frequencies of 0.26.The distributions of the three genotypes were in accordance with Hardy-Weinberg Equilibrium (P=0.884).There was no statistical difference in the data distribution of the genotypes on clinical indexes at baseline.Overall survival time(OS)was longer in patients with allele A and genotype GA plus AA[2.73 years(95 %CI:1.03-5.11 years)]than in patients with GG genotype[1.64 years(95 % CI:0.71-4.34),(P=0.003)].The replase free survival(RFS) was longer in patients with allele A and genotype GA plus AA[2.06 years(95%CI:0.95-4.87)]than in patients with GG genotype[1.12 years(95%CI:0.56-4.11),P =0.032)].Adjusted by using multivariate Cox regression analysis,GA plus AA genotypes still showed a better effect on OS (HR =0.51,P =0.013)than did GG genotypes.In the 65 pretreatment bone marrow specimens,the expression level of WT1 mRNA in bone marrow cells was higher in patients with GG genotype than in patients with GA plus AA genotype(P < 0.001).Conclusions Among elderly AML patients treated by cytarabine-based chemotherapy,the WT1 rs16754 may impact the clinical prognosis of AML patients by influencing the mRNA expression of WT1.

3.
Chinese Journal of Stomatology ; (12): 138-141, 2019.
Article in Chinese | WPRIM | ID: wpr-804703

ABSTRACT

As one of the rapid prototyping technology, three-dimensional (3D) printing is booming since its birth. 3D printing has already been applied in biomedical engineering, medical mold processing and many healthcare fields, but its application in dental education is still in the exploratory stage. Nowadays, educators are seeking to integrate 3D printing and dental education. On the basis of the advantages of 3D printing, the quality of dental education will be further improved and students′ enthusiasm for learning will be stimulated. This article will focus on elaborating the recent advances of 3D printing in dental education and exploring its direction in the field of teaching.

4.
Article in Chinese | WPRIM | ID: wpr-357481

ABSTRACT

Objective The aim of this study is to evaluate the effect of repeated sintering and variation in thickness on the color and microstructure of dental lithium disilicate-based glass ceramic veneers. Methods A total of 24 computer aided design and computer aided manufacturing (CAD/CAM) veneers was fabricated using the IPS e.max-CAD LS2 and then randomly divided into four groups (S0, S1, S2, S3; n=6). Each group was sintered 0, 1, 2, 3 times individually according to the manufacturer's recommendation. The color parameters (L, C, H, a, b values) of all the specimens were measured by a Vita easyshade dental colorimeter. The results were statistically analyzed using the SAS 9.1.3 software for MANOVA and LSD. Subsequently, the microstructures of the intersecting surfaces of the specimens were observed by scanning electron microscopy (SEM). Results After repeated sintering, the L value significantly decreased (P<0.05). For the C and b values, statistical differences were observed among the groups except between S2 and S3. SEM results showed that the interlocking microstructures of rod-shaped Li₂Si₂O₅ crystals became more compact when the number of sintering times was increased. Conclusion Repeated sintering exhibited significant influence on the color of the IPS e.max-CAD LS2 veneers.

5.
Chinese Journal of Stomatology ; (12): 582-584, 2017.
Article in Chinese | WPRIM | ID: wpr-809236

ABSTRACT

Degradation of composite resin during ageing always produces micro-cracks, the latter could gradually expand, leading to the fracture of tooth restoration. In order to extend the service life of composite resin by repairing cracks intelligently, self-healing microcapsule models have been introduced in resin-based dental materials. This paper will present the concept and classification of self-healing materials, and review the research progresses on self-healing dental resin.

6.
Chinese Journal of Stomatology ; (12): 278-282, 2017.
Article in Chinese | WPRIM | ID: wpr-808619

ABSTRACT

Objective@#To evaluate a nano-hydroxyapatite (nano-HA) desensitizing paste application on the bond strength of three self-etch adhesives.@*Methods@#Three dentin specimens of about 1 mm thick were cut from two teeth. Scanning electron microscope (SEM) was used to evaluate the dentin surfaces without treatment, after citric acid treatment and after nano-HA treatment. Thirty-six intact third molars extracted for surgical reasons were cut to remove the occlusal enamel with isomet, and then were etched with 1% citric acid for 20 s to simulate the sensitive dentin and divided into two groups randomly using a table of random numbers (n=18): the control group (no treatment) and the HA treated group (with nano-HA paste treatment). Each group was divided into three subgroups randomly using a table of random numbers (n=6). Subgroup A, B and C was bonded with G-Bond, Clearfil S3 Bond and FL-Bond Ⅱ according to the manufacture's instruction separately. At 24 h after bonding procedure, and after water storage for 6 months, microtensile bond strength of the specimens was tested and the failure mode was analyzed.@*Results@#SEM obeservation showed that citric acid could open the dentin tubules to set up the sensitive dentin model, and the nano-HA could occlude the dentin tubules effectively. For subgroup A, bonding strength of specimens treated with nano-HA ([41.14±8.91] MPa) was significantly high than that of the control group ([34.27±6.16] MPa) at 24 h after bonding procedure (P<0.05). However, after 6 month water ageing, the bonding strength of the control group and the HA treated group showed no significant difference (P>0.05). For subgroup B, specimens with nano-HA application showed lower bonding strength ([30.87±6.41] MPa) than that of the control group ([36.73±5.82] MPa) at 24 h after bonding procedure (P<0.05), and after 6 month water ageing, the bond strength of nano-HA application ([25.73±6.99] MPa) was also lower than that of the control group ([32.33±5.08] MPa) (P<0.05). For subgroup C, the bond strength of the control group and the HA treated group have no significant difference either before or after 6 month water ageing (P>0.05). Failure mode analysis showed that more than half of the samples in all groups were adhesive failure.@*Conclusions@#Nano-HA treatment decreased the bond strength of subgroup B, while had no adverse effect on subgroup A and subgroup C.

7.
Article in Chinese | WPRIM | ID: wpr-807954

ABSTRACT

Dental implants have been widely accepted as a predictable and reliable tool for dental reconstruction with the development of the economy. The design of implant-abutment connections has influence on mechanical properties and biological characteristics of implants. There are two types of implant-abutment connections, the external and the internal connections. Morse taper connection is one of the internal connections and its conical shape creates significant friction via the high propensity of parallelism between the two structures within the joint space. Several studies showed that Morse taper connection performed well in terms of survival rate, stability, bacterial seal and marginal bone loss. Recently, clinical studies indicate implants combining Morse taper connection with platform switching are helpful in reducing marginal bone absorption. This review aims at analyzing the features and advantages of Morse taper connection.

8.
Article in Chinese | WPRIM | ID: wpr-615660

ABSTRACT

Objective To observe the morphology of ethanol-wet dentin surfaces and detect their nano-scale adhesion force (Fad) by atomic force microscopy (AFM) in order to explore the potential mechanism of ethanol-wet bonding in improving clinical dentin bonding effectiveness.Methods Dentin slices from human premolar roots were prepared into flat ones, polished, and then randomly divided into five groups.All the specimens were acid-etched, rinsed, and left moist.They were then treated with 100% ethanol for 0s (control group), 20s, 60s, 3×60s, or stepwise ethanol application.Afterwards, each group was scanned for the morphology in air and the Fad was probed by AFM.One-way ANOVA followed by Tukey`s test was employed for multiple comparisons using SPSS16.0.Results Compared with control group, ethanol-wet dentine produced a less undulating and relatively smooth surface topography.Ethanol-wet protocol significantly decreased the value of Fad in the experimental groups (P0.05).Conclusion When using AFM in air, ethanol-wet protocol with longer time can produce a less undulating and relatively smooth surface topography and decrease the Fad, whichindicates that the water saturated in dentin matrix was replaced more thoroughly by longer ethanol application time.This will benefit hydrophobicity of the dentin bonding interface.

9.
Chinese Journal of Pathophysiology ; (12): 1921-1931, 2017.
Article in Chinese | WPRIM | ID: wpr-667676

ABSTRACT

AIM:To investigate the effect of bone marrow mesenchymal stem cell(BMSC) transplantation on learning and memory abilities and pathological changes of Alzheimer disease (AD) mice and the molecular mechanisms. METHODS:C57/BL6 wild-type (WT) and transgenic(Tg) mice were randomly divided into 4 groups:WT/PBS group, WT/BMSCs group,Tg/PBS group and Tg/BMSCs group. The mice were administered with PBS or BMSCs via intracere-broventricular injection. Spatial learning and memory abilities of the mice were evaluated by Morris water maze test on the 3rd day after surgery. Real-time PCR was applied to detect the mRNA expression of CX3C chemokine ligand 1 (CX3CL1),CX3C chemokine receptor 1 (CX3CR1), IL-1β, TNF-α, Nurr1, YM1, insulin-degrading enzyme (IDE) and matrix metalloproteinase 9(MMP9). The protein levels of CX3CL1 and Aβ42 were measured by ELISA. Western blot was used to detect the protein expression of postsynaptic density protein 95 (PSD95) and synaptophysin (SYP). RE-SULTS:The transplanted BMSCs were observed near the hippocampus of APP/PS1 mice on the 10th postoperative day. The escape latency of the mice in Tg/PBS group was significantly longer than that in the WT/PBS mice(P<0.05). Com-pared with Tg/PBS group,the escape latency of Tg/BMSCs group was significantly shorter (P<0.05), and the mRNA and protein levels of CX3CL1 in Tg/BMSCs group were significantly higher than those in Tg/PBS group (P<0.01). The results of immunohistofluorescence staining showed that BMSC transplantation promoted the activation of microglia in the brain of WT and Tg mice. The mRNA expression of YM1 was up-regulated in WT/BMSCs group and Tg/BMSCs group (P<0.05). Compared with WT/PBS mice, the mRNA expression of TNF-α in the cortex and hippocampus of Tg/PBS group was significantly increased (P<0.05),and the mRNA expression of Nurr1 in the cortex was significantly decreased (P<0.01). Meanwhile,the mRNA expression of TNF-α in the cortex of Tg/BMSCs mice was decreased(P<0.01) and the mRNA expression of CX3CR1 and Nurr1 was up-regulated compared with Tg/PBS group (P<0.05). The results of Western blot showed that the protein levels of PSD95,p85,p110 and p-Akt in Tg/BMSCs group were significantly higher than those in Tg/PBS group (P<0.05). Finally, BMSC transplantation reduced the protein level of Aβ42 in APP/PS1 mice(P<0.05), and increased the mRNA expression of IDE and MMP9 in the hippocampus (P <0.05). CONCLU-SION:BMSC transplantation modulates neuroinflammatory responses and promotes neuroprotective factor and synaptic pro-tein expression,thus improving the learning and memory abilities in the APP/PS1 mice,which may be achieved by up-reg-ulating the expression of CX3CL1.

10.
Chinese Journal of Stomatology ; (12): 189-192, 2016.
Article in Chinese | WPRIM | ID: wpr-259418

ABSTRACT

The bonding restoration has become an important clinical technique for the development of dental bonding technology. Because of its easy operation and the maximum preservation of tooth tissues, bonding repair is widely used in dental restoration. The recent multi-mode universal adhesives have brought new progress in dental bonding restoration. In this article the universal adhesives were reviewed according to its definition, development, improvement, application features and possible problems.


Subject(s)
Adhesives , Dental Bonding , Methods , Dentin-Bonding Agents , Humans , Technology, Dental
11.
Article in Chinese | WPRIM | ID: wpr-491721

ABSTRACT

BACKGROUND:The physical properties and chemical composition of teeth are very similar with human bone tissue, and there are a larger proportion of inorganic components. Therefore, tooth can be considered as a potential repair material for autologous or alogeneic bone defects. OBJECTIVE:To prepare polyetheretherketone/odontogenic biphasic bioceramic composite, and to test its mechanical properties. METHODS: The humanin vitro teeth of clinical waste were colected. The organic components were removed after a preliminary calcination. Another calcination was conducted after soaking in diammonium phosphate solution for 24 hours to prepare the biphasic ceramics with the main components of hydroxyapatite and β-tricalcium phosphate. The biphasic ceramics were ground and sieved using 200-mesh sieve folowed by impregnation in organic foam to prepare polyetheretherketone/odontogenic biphasic bioceramics. Phase analysis, scanning electron microscopy, elemental analysis, porosity, compressive strength and bond strength test were conducted. RESULTS AND CONCLUSION:Polyetheretherketone/odontogenic biphasic bioceramics presented porous network structure and interconnected holes, with the aperture of 100-800 μm, porosity of 73.65%, compressive strength of (165.260±11.703) N, bond strength of (14.63±6.21) MPa. P element content accounted for 19.8%, and Ca element content accounted for 40.5%. The main phases were β- tricalcium phosphate and hydroxyapatite. These results demonstrate that polyetheretherketone/odontogenic biphasic bioceramics have good mechanical properties.

12.
Chinese Journal of Stomatology ; (12): 362-366, 2014.
Article in Chinese | WPRIM | ID: wpr-260820

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the effect of pretreatment with ethanol on dentin to compensate premature volatilization of self-etch adhesive system.</p><p><b>METHODS</b>Thirty-two intact human molars were randomly divided into two groups using a table of random numbers (n = 16): A, an acetone-base adhesive (G-bond) and B, an ethanol-based adhesive (Clearfile S(3) bond). Then each group was randomly assigned into foursub groups (n = 4) : group 1, no premature volatilization; group 2, premature volatilization; group 3, premature volatilization + stepwise ethanol pretreatments; and group 4, premature volatilization + absolute ethanol treatment. After composite resin building, microtensile bond strengths (MTBS) of each subgroup were then tested. Fracture modes were classified by stereomicroscopy and representative interface was observed by field-emission scanning electron microscopy (FE-SEM).</p><p><b>RESULTS</b>For adhesive A, there was significant difference on MTBS among different subgroups (P < 0.05); the MTBS of group A2 [(26 ± 12) MPa] and A4 [(27 ± 7) MPa] was lower than that of group A1 [(41 ± 11) MPa] and A3 [(40 ± 11) MPa] (P < 0.05). No significant different was found between group A2 and A4 (P > 0.05); neither between group A1 and A3 (P > 0.05). For adhesive B, there was no difference on MTBS among different subgroups (P > 0.05).FE-SEM showed that the main fracture mode was located at the bottom of the hybrid layer for adhesive A groups, the collagen fibrils were capsulated by resin monomers more densely in group A1 and group A3 in comparison with other two subgroups.For adhesive B groups, the main failure modes were at the top of the hybrid layer.</p><p><b>CONCLUSIONS</b>Premature volatilization can obviously decrease the bonding strength of acetone-base self-etch adhesives, but has no significant effect on ethanol-based self-etch adhesives. Dentin pretreatment with a series of increasing ethanol concentrations can effectively compensate the adverse effect of premature volatilization of acetone-base self-etch adhesives on bonding strength.</p>


Subject(s)
Adhesives , Composite Resins , Dental Bonding , Dental Materials , Dental Stress Analysis , Dentin , Dentin-Bonding Agents , Ethanol , Chemistry , Humans , Methacrylates , Microscopy, Electron, Scanning , Molar , Resin Cements , Tensile Strength , Volatilization
13.
Chinese Journal of Stomatology ; (12): 165-169, 2013.
Article in Chinese | WPRIM | ID: wpr-293632

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the effect of an 8% arginine-CaCO3 containing desensitizing polishing paste on bonding strength of two self-etching adhesives to dentin.</p><p><b>METHODS</b>Thirty-six intact human premolars extracted for orthodontic reasons were collected within 1 month after extraction and randomly assigned into three groups using a table of random numbers (n = 12): specimens without any treatment served as control. In the polishing powder group specimens were polished with a slurry of pumice, and in the desensitizing polishing paste group dentin surfaces of the sample teeth were treated with 8% arginine-CaCO3 containing desensitizing polishing paste. Then each group was divided into two sub-groups using a table of random numbers in order to evaluate the bonding strength of two self-etching adhesive agents (G-Bond, GC; Fl-Bond II, Shofu). Microtensile bond strength test was conducted immediately and after 5000 thermocycling (n = 15). Scanning electron microscope (SEM) was used to evaluate the occluding effect of the desensitizing polishing paste.</p><p><b>RESULTS</b>In the pre-thermocycling stage, there were no significant differences in Fl-Bond II bonding strength among the three groups [control: (30.34 ± 5.42) MPa, polishing powder group: (29.72 ± 5.16) MPa, desensitizing polishing paste group: (31.53 ± 4.86) MPa] (P > 0.05). However there were significant differences among the three groups in G-Bond bonding strength [control: (38.19 ± 4.42) MPa, polishing powder group: (36.47 ± 4.72) MPa, desensitizing polishing paste group: (46.88 ± 7.83) MPa] (P < 0.05). After thermocycling process, there were no significant differences in bonding strength among the three groups in both G-Bond groups and Fl-Bond II groups. SEM observation showed that the desensitizing polishing paste could occlude open dentinal tubules effectively, and the application of self-etching adhesives could re-open the dentinal tubular orifices. An even layer can be seen on the dentin surface treated with self-etching adhesive containing functional monomers.</p><p><b>CONCLUSIONS</b>The 8% arginine-CaCO3 containing desensitizing polishing paste could effectively occlude dentinal tubules, thus may have potential benefits in preventing post-operative sensitivity. Additionally, it had no adverse effect on bonding strength of self-etching adhesives to dentin.</p>


Subject(s)
Acid Etching, Dental , Dentin Desensitizing Agents , Dentin-Bonding Agents , Humans , In Vitro Techniques , Random Allocation , Tensile Strength
14.
Article in Chinese | WPRIM | ID: wpr-315935

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the effect of an arginine-containing antihypersensitivity polishing paste on Streptococcus mutans (S. mutans) adhesion to treated dentin.</p><p><b>METHODS</b>Dentin discs were treated with acid to expose dentin tubules, and then polished with either pumice or a polishing paste containing arginine. The surface roughness of the treated dentin was measured. The effects of dentin treatment on S. mutans adhesion and glucosyltransferase (GTFs) gene expression were also evaluated.</p><p><b>RESULTS</b>The surface roughness decreased after polishing with both pumice and arginine-containing polishing paste. Moreover, the polishing paste affected gtfB and gtfC expressions.</p><p><b>CONCLUSION</b>The arginine-containing polishing paste affects S. mutans adhesion, as well as gtfB and gtfC expressions. The polishing paste may be used to prevent caries in exposed dentin areas.</p>


Subject(s)
Arginine , Bacterial Adhesion , Dentin , Humans , Ointments , Silicates , Streptococcus mutans , Toothpastes
15.
Article in Chinese | WPRIM | ID: wpr-336406

ABSTRACT

Dental bonding technique has become an essential technique for dental clinical practice over the past several decades. Dental adhesion is widely used in direct and indirect restorations. However, problems such as technique sensitivity, postoperative sensitivity, secondary caries and marginal discoloration always appear in the dental bonding procedures. Fiber post and all-ceramic restoration bonding are essential step in esthetic dentistry. If these problems are not well handled, it will result in failure of the restorations. Therefore, the aim of this article is to provide adequate consultations and advice for the clinical practitioners based on the author's experience and relevant literatures.


Subject(s)
Ceramics , Dental Bonding , Dental Caries , Dental Restoration Failure , Humans
16.
Chinese Journal of Stomatology ; (12): 755-758, 2011.
Article in Chinese | WPRIM | ID: wpr-306345

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the micropermeability on bonding hydrophobic adhesive to dentin with ethanol-wet bonding under simulated pulp pressure.</p><p><b>METHODS</b>Twenty-four intact human third molars were used in the study. After the enamel of occlusal surfaces was removed, the molars were randomly divided into six groups. Adper Scotchbond Multi-Purpose was used in the control group; in the experimental groups, the dentin surfaces were saturated with ethanol for 20 s (group 1), 1 min (group 2), 2 min (group 3), 3 min (group 4) or with a series of increasing ethanol concentrations before application of hydrophobic adhesive (group 5). All the bonding procedures were done under simulated pulp pressure. After 24 hours, micro-tensile bond strength test were performed on the specimens. Bonding interfaces were observed under laser scanning confocal microscope (LSCM) after the pulp chamber were filled with a water-soluble fluoroprobe rhodamine B for 3 hours.</p><p><b>RESULTS</b>Compared with the control group [(38.14 ± 4.97) MPa], bond strengths in group 1 [(21.02 ± 7.23) MPa] and group 2 [(29.64 ± 3.81) MPa] were statistically lower (P > 0.05), while bond strength in group 3 [(38.40 ± 5.03) MPa], group 4 [(37.26 ± 4.68) MPa] and group 5 [(40.12 ± 5.95) MPa] were similar to the control group (P < 0.05). The images taken by LSCM showed that with extension of ethanol-wet time, the deposition of fluorescent dye in hybrid layer and along the dentinal tubules decreased gradually. Especially in group 5, only spare fluorescent dye deposition could be detected in the hybrid layer.</p><p><b>CONCLUSIONS</b>Dentin saturated with ethanol for more than 2 min before bonding hydrophobic adhesive to dentin could provide favorable bond strength and decreased the micropermeability of bonding interfaces under simulated pulp pressure.</p>


Subject(s)
Acid Etching, Dental , Composite Resins , Dental Bonding , Dental Cements , Dental Enamel , Dental Pulp Cavity , Dentin , Dentin-Bonding Agents , Ethanol , Humans , Hydrophobic and Hydrophilic Interactions , Materials Testing , Resin Cements , Tensile Strength , Water
17.
Chinese Journal of Stomatology ; (12): 356-359, 2008.
Article in Chinese | WPRIM | ID: wpr-235902

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the bond strength of total-etch or self-etch dentin bonding agents after using two different dentin desensitizers on exposed dentin and investigate the bond interface by scanning electron microscope (SEM).</p><p><b>METHODS</b>Thirty intact and non-carious human third molars were used. The occlusal enamel was removed with the use of a slow-speed saw under water cooling. These teeth were divided into three groups using a table of random numbers with 10 teeth each. These three groups were treated with water (Group C), UltraEZ (Group U) and MI Paste (Group M) respectively. Then 10 teeth from each group were divided into A subgroup (n = 5) bonded with Single Bond 2 adhesive system and B subgroup (n = 5) bonded with Xeno III adhesive system according to manufacturers' instructions. A block of composite resin was build up to 4-5 mm. All the teeth were sectioned occluso-gingivally to obtain bar-shaped specimens with bonded surface area about 0.9 mm x 0.9 mm. The tension of the sample was tested by a microtensile tester at 1 mm/min. The mean values of bond strength were compared using one-way ANOVA. Three samples were chosen randomly from each of six groups for SEM investigation.</p><p><b>RESULTS</b>There were no significant differences between Group U and Group C both in A and B subgroups. While there were significant differences between Group M and Group C in two bonding-agent subgroups. For SEM, the hybrid layer was thin and dense in six groups. Both total-etch and self-etch bonding systems could get fair resin tag infiltration in Group C and Group U. In Group M, the resin tags were relatively shorter and fewer than the anterior mentioned two groups.</p><p><b>CONCLUSIONS</b>UltraEZ had no effect on bond strength of both kinds of dentin bonding agents, while MI paste could diminish bond strength.</p>


Subject(s)
Bisphenol A-Glycidyl Methacrylate , Chemistry , Dental Materials , Dental Stress Analysis , Dentin-Bonding Agents , Chemistry , Humans , Materials Testing , Molar, Third , Nitrates , Chemistry , Potassium Compounds , Chemistry
18.
Chinese Journal of Stomatology ; (12): 323-326, 2006.
Article in Chinese | WPRIM | ID: wpr-354383

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the microtensile bond strength and bond interface of total-etch or self-etch adhesives to normal dentin and caries-affected dentin.</p><p><b>METHODS</b>A total of 20 molars with occlusal caries lesion were used. The caries-affected dentin was obtained by removing the caries-infected dentin under the guidance of the caries detector. Beyond the level of caries-affected dentin all the enamel and partial dentin were removed. The adhesive systems, two total-etch adhesives (All-Bond 2, Prime&Bond NT) and two self-etch adhesives (Clearfil SE Bond, Xeno III) were applied respectively under the instructions of manufacturers. A block of composite resin was build up superficially. All the teeth were sectioned to obtain bar-shaped specimens with bonded surface area about 0.9 mm x 0.9 mm. The specimens were divided into normal dentin group and caries-affected dentin group via stereomicroscope. The bond strength was tested in a microtensile tester with a crosshead speed of 1 mm/min. The mean values of bond strength were compared using two-way ANOVA. The bonding interface between the dentin and adhesives was qualitatively evaluated under the observation of scanning electron microscope (SEM).</p><p><b>RESULTS</b>Two-way ANOVA revealed a significant influence of both the type of dentin and the adhesive systems tested on microtensile bond strength values. All the adhesives attained higher strength in normal dentin. In normal dentin, there was no significant difference between total-etch and self-etch adhesives. In caries-affected dentin, bond strength of Xeno III was significantly lower than the others. For SEM, the hybrid layer in caries-affected dentin was thicker but more porous than that in normal dentin. Compared with normal dentin, there was fewer resin tag exhibited in caries-affected dentin and no lateral branches were observed.</p><p><b>CONCLUSIONS</b>The total-etch adhesive had higher bond strength than self-etch adhesive systems in caries-affected dentin.</p>


Subject(s)
Acid Etching, Dental , Adult , Dental Caries , Therapeutics , Dentin , Dentin-Bonding Agents , Classification , Humans , Middle Aged , Tensile Strength , Tooth Demineralization , Therapeutics
19.
Article in Chinese | WPRIM | ID: wpr-683499

ABSTRACT

Objective To study the technique and clinical significance of percutaneous biopsy of transplanted liver guided by CT.Methods 19 transplanted liver were undergone 25 times of percutaneous biopsy and the pathomorphologic changes were demonstrated by HE staining.Results The successful rate of the percutaneous biopsy was 100% for all the 25 times of this procedure,including acute rejection on 9 episodes,preservation perfusion retrauma in 6,bile duct strictures in 4,drug-induced injury in 4,chronic rejection in 1 and acute hepatic necrosis in 1.Conclusions CT-guided percutaneous biopsy is an important method for diagnosing transplanted liver injury and providing great value for distinguishment of the causes for transplanted liver injury.(J Intervent Radiol,2007,16:855-857)

20.
Chinese Medical Journal ; (24): 1623-1628, 2005.
Article in English | WPRIM | ID: wpr-320723

ABSTRACT

<p><b>BACKGROUND</b>The wet-bonding technique is recommended for the one-bottle dentin adhesive systems, but the moisture concept varies widely among the instructions of manufacturers as well as among investigators. The aim of this study was to evaluate the effects of different dentin surface moisture on the microtensile bond strength(s) of an ethanol/water-based adhesive system and an acetone-based system to dentin.</p><p><b>METHODS</b>Forty intact human premolars extracted for orthodontic reasons were used. Superficial occlusal flat dentin surfaces of these premolars were exposed, finished with wet 600-grit silicon carbide paper. Under four wet and dry conditions (overwet, blot dry, one-second dry and desiccated), resin composite was bonded to dentin by using Single Bond (SB) or Prime & Bond NT (PB) according to the manufacturers' instructions. The teeth were longitudinally sectioned in the "x" and "y" directions to obtain bonded beams with a cross-sectional area of 0.81 mm(2) with a slow-speed diamond saw. The bonded specimens were tested in tension at a crosshead speed of 1 mm/min until failure of the bonds. Failure modes were observed with a scanning electron microscope. The mean bond strengths were analyzed by one-way ANOVA and Turkey's test.</p><p><b>RESULTS</b>The bond strength of the overwet/SB, blot dry/SB, one-second dry/SB and desiccated/SB groups was 10.87 MPa, 22.47 MPa, 24.91 MPa and 12.99 MPa, respectively. The bond strength of the overwet/PB, blot dry/PB, one-second dry/PB and desiccated/PB groups was 10.02 MPa, 20.67 MPa, 21.82 MPa and 10.09 MPa, respectively. For both SB and PB, the blot dry group and one-second dry group revealed significantly higher bond strengths than the overwet and desiccated groups (P < 0.05).</p><p><b>CONCLUSIONS</b>In order to achieve the highest bond strength to dentin, keeping the dentin surface in an appropriately moist condition is critical for the one-bottle dentin adhesive systems with ethanol/water or acetone solvent.</p>


Subject(s)
Adolescent , Adult , Dental Bonding , Dentin-Bonding Agents , Pharmacology , Humans , Solvents , Tensile Strength , Water
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