OBJECTIVE: To select the most effective method among different masking treatments, such as different thickness and transparence, tissue surface's opaque coating, and opaque resin cement to restore discolored teeth esthetically by porcelain veneer. METHODS: Four extracted intact maxillary central incisors were prepared for porcelain veneer restoration and each three heat pressed porcelain veneers from three thicknesses (0.8 mm, 1.0 mm, 1.2 mm) and two transparency(high transparence, HT and low transparence, LT))in Vita shade A2 were fabricated for each tooth, in total of 72 pieces. The surfaces of three prepared teeth were then painted to mimic situations of severe dental fluorosis, severe tetracycline teeth, and necrotic teeth. Each of the veneers was temporarily cemented to the corresponding tooth surface using try-in cements with three different colors (transparent, opaque, and yellow), then used the shade guide (3D master) and electronic colorimeter (easy shade) to record the shade of each porcelain veneer through hue, lightness, and chroma reading. After that, high-transparence porcelain veneers in thickness of 0.8 mm was fused with a layer of opaque porcelain in tissue surface, and were shade matched again after cementation. Statistic treatments were performed to analyze the difference in each masking method. RESULTS: For each 0.2 mm increase in the veneer thickness of porcelain, the average lightness was reduced by 1 unit, while the chroma was not changed which was independent of the type of the resin cements. When the thickness of the porcelain veneer was decreased to 0.8 mm, the opacity effect was not remarkable even if a low-transparence porcelain veneer was used. Transparent and yellow resin cements had poor opaque performance, while opaque resin cement could reduce the lightness by 2 units and the chroma was also reduced. The opaque layer of the tissue surface could be applied uniformly, and the lightness and chroma could be reduced to Vita 2M1 to 2M1.5 levels regardless of the color of resin cements, which suggested a stable opacity effect for different discolored teeth in this study. CONCLUSION For porcelain veneer restoration of discolored teeth, thickened veneers are the most effective means to display a natural transmittance and color. Tissue surface's opacity coatings and opaque resin cements can also be used to reduce grayscale and increase lightness.
Color ; Humans ; Materials Testing ; Prosthesis Coloring ; Resin Cements ; Tooth Discoloration/therapy*

Abstract: Objective　To detect the distribution of CYP2A6∗2, CYP2A6∗10, CYP2A6∗17, CYP2B6∗4, CYP2B6∗6, and CYP2B6∗18 loci affecting the metabolism of artemisinins in Kazak population in Xinjiang. To explore the pharmacogenetic background of the Kazak population in Xinjiang for artemisinin drugs and provide clinical decision support for the treatment and prevention of malaria based on artemisinin drugs. Methods　Six SNPs including CYP2A6∗2, CYP2A6∗10, CYP2A6∗17, CYP2B6∗4, CYP2B6∗6, and CYP2B6∗18 were selected for the sequencing experiment. 330 whole blood samples were collected from the Kazak population in Xinjiang. After extracting the whole blood DNA genome, multiplex PCR and high-throughput sequencing were used for genotyping. The allele frequencies were analyzed using the Hardy-Weinberg equilibrium. Results　In this study all SNPs follow the Hardy-Weinberg equilibrium (P>0.05), there was no significant difference in the distribution of SNPs between different genders (P>0.05). The number of successfully sequenced samples of CYP2A6∗2, CYP2A6∗10, CYP2A6∗17, CYP2B6∗4, CYP2B6∗6, and CYP2B6∗18 were 326, 319, 328, 318, 322 and 328 respectively. The frequencies of variant alleles of CYP2A6∗2, CYP2A6∗10, CYP2A6∗17, CYP2B6∗4, CYP2B6∗6, and CYP2B6∗18 in Kazak population are: 0.61%, 0%, 0%, 30.97%, 22.98%, 0%. Conclusions　Mutation alleles affecting the metabolism of artemisinins exist in the Kazak population in Xinjiang. When using artemisinins, the relationship between the drug effect and individual pharmacogenetic background should be further explored.

OBJECTIVETo evaluate the dimensional stability and detail reproduction of five additional silicone impression materials after autoclave sterilization.

METHODSImpressions were made on the ISO 4823 standard mold containing several marking lines, in five kinds of additional silicone. All the impressions were sterilized by high temperature and pressure (135 °C, 212.8 kPa) for 25 min. Linear measurements of pre-sterilization and post-sterilization were made with a measuring microscope. Statistical analysis utilized single-factor analysis with pair-wise comparison of mean values when appropriate. Hypothesis testing was conducted at alpha = 0.05.

RESULTSNo significant difference was found between the pre-sterilization and post-sterilization conditions for all locations, and all the absolute valuse of linear rate of change less than 8%. All the sterilization by the autoclave did not affect the surfuce detail reproduction of the 5 impression materials.

CONCLUSIONSThe dimensional stability and detail reproduction of the five additional silicone impression materials in the study was unaffected by autoclave sterilization.

Dental Impression Materials ; chemistry ; Dental Models ; Hot Temperature ; Materials Testing ; Microscopy ; Polyvinyls ; chemistry ; Silicone Elastomers ; chemistry ; Siloxanes ; chemistry ; Sterilization ; methods

Objective To investigate the value of diffusion tensor imaging (DTI) in evaluating the injury of corticospinal tract (CST), including the motor dysfunction and the integrity of CST, in patients with hypertensive intracerebral hemorrhage (HICH), and explore the relation between DTI results and the recovery of myodynamia. Methods Clinical data of 10 healthy volunteers and 35 patients with HICH, admitted to our hospital and performed evacuation of hematoma from November 2006 to May 2009, were retrospectively analyzed; DTI by using a 3.0T MR canner were chosen on them and the imaging was analyzed by Functool software. The changes of directionality and integrity of SCT were analyzed on fractional anisorropic (FA) map, color-coded directional map, and three-dimensional white matter tractography. Myodynamic examination at Brunnstrom standard 2 months after rehabilitation nursing was performed in these patients. The correlation between the injured degree of CST and the recovery of myodynamia was analyzed. Results Fiber tractography derived from DTI was consistent with known white matter fiber anatomy in 10 healthy volunteers. Three patterns of corticospinal tract involvement were identified in 35 patients: the intact one in 11 patients (the ipsilateral corticospinal tract was almost the same as contralateral corticospinal tract), the partially damaged one in 18 patients (the ipsilateral corticospinal tract was less than 2/3 but larger than 1/3 contralateral corticospinal tract) and the almost completely damaged one in 6 patients (the ipsilateral corticospinal tract was less than 1/3 contralateral corticospinal tract). Different pattern had totally different clinical outcome and the intact one had a full recovery. The ipsilateral corticospinal tract showed significantly lower Brunnstrom scores of the upper extremities than the ipsilateral one (P<0.05); the Brunnstorm scores and the value of myodynamia among the 3 patterns were statistically different (P<0.05). The recovery of motor function was negatively correlated to the injured degree of CST (r=-0.931, P=0.000). Conclusion The DTI, offering the optimal visualization of white matter tracts can detect the injured degree of the corticospinal tracts and predicate the prognosis to some extent, thus, early evaluation of corticospinal tract injury based on DTI can provide predictive value for motor functional outcome in patients with HICH.

OBJECTIVESTo evaluate the effect of shade guide training box and shade guide training software on shade matching ability of observers when used separately. To find out the difference between two training plans when the two training methods were used in combination, and to provide information on shade matching training system.

METHODSSixty-two postgraduate dental students who specialized in prosthodontics with 1 to 5 year clinical experience were enrolled in this study. At base line, each participant were asked to match 7 standard shade tabs which have been randomly chosen from Vita 3D-Master shade guide and 7 intermediate shade tabs from Vita bleached guide 3D-Master. Then the subjects were allocated to 2 groups [Toothguide Training Box (TTB) group and Toothguide Training (TT) group] according to the baseline data. Participants in group TTB received training session once a week for 3 weeks, while those in group TT received TT training session once a week for 3 weeks. All participants took a middle term shade-matching test. Then the two groups exchange the training methods and repeat the whole process, a final test was given to each participant. The elapsed time and number of accurate shade matching were recorded for each training session. Wilcoxon signed ranks test and ANOVA were used in data analysis.

RESULTSThere were no significant differences in the number of accurate shade matching (standard shade tab and the sum) between group TTB (4.4 +/- 1.3 and 5.3 +/- 1.6) and TT (4.0 +/- 1.4 and 4.9 +/- 1.5) in the middle term test with higher value found in group TTB. In the final test, the number of accurate shade matching (standard shade tab and the sum) in group TT (4.9 +/- 0.8 and 6.4 +/- 0.8) was higher than that in group TTB (4.7 +/- 1.1 and 5.8 +/- 0.9), but significant difference was found only when the sum number of accurate shade matching was compared between the two groups (P < 0.05). There was no significant difference between data from middle term test and from final test in group TTB; while in group TT, the number of accurate shade matching in the final test was significantly increased compared with that in the middle term test (P < 0.05).

CONCLUSIONSWhen used in combination, TT training followed by TTB training is recommended.

Analysis of Variance ; Humans ; Observer Variation ; Prosthesis Coloring ; methods ; Prosthodontics ; education ; Software ; Students, Dental

OBJECTIVETo compare the shade matching accuracy between tabs of shade guide and tabs out of shade guide by prosthodontists.

METHODSSixty-two graduate students who had 1 to 5 years clinical experience without color blindness were included in this study. Twenty-nine tabs from Vita 3D-Master shadeguide and 7 tabs out of Vita 3D-Master shade guide but from Vita Bleachedguide 3D-Master were taken as the targets of shade matching and observed under the standard light. Subjects' shade matching accuracy on tabs of shadeguide and tabs out of shadeguide was recorded. Frequency of right match was analyzed using Monte Carlo exact probability-test. Wilcoxin test was used to analyze the difference between each group on ranked data of value, chroma and hue.

RESULTSThe shade matching accuracy of tabs of shade guide [45.9% (199/434)] was significantly higher than that of tabs out of shade guide [9.0% (39/434)]. There was significant difference between the two kinds of tabs of ranked data of value [0.2 (0.1 - 0.3), 0.4 (0.4 - 0.5)] and chroma [0.2 (0.1 - 0.4), 0.5 (0.4 - 0.6), P < 0.01, but there was no significant difference in hue data [0.3 (0.1 - 0.4), 0.3 (0.1 - 0.4)].

CONCLUSIONSThe shade matching ability of prosthodontists on tabs out of shade guide is lower than that on tabs of shadeguide. To fulfill clinical need, more training is necessary.

Dentists ; psychology ; Esthetics, Dental ; Humans ; Observer Variation ; Pattern Recognition, Visual ; Prosthesis Coloring ; methods ; Reproducibility of Results

OBJECTIVETo test ΔE between measured value and right value from the Crystaleye complete-tooth spectrophotometer, and to evaluate the accuracy rate of the spectrophotometer.

METHODSTwenty prosthodontists participated in the study. Each of them used Vita 3D-Master shadeguide to do the shade matching, and used Crystaleye complete-tooth spectrophotometer (before and after the test training) tested the middle of eight fixed tabs from shadeguide in the dark box. The results of shade matching and spectrophotometer were recorded. The accuracy rate of shade matching and the spectrophotometer before and after training were calculated.

RESULTSThe average accuracy rate of shade matching was 49%. The average accuracy rate of the spectrophotometer before and after training was 83% and 99%.

CONCLUSIONSThe accuracy of the spectrophotometer was significant higher than that in shade matching, and training can improve the accuracy rate.

Color ; standards ; Colorimetry ; instrumentation ; Dental Clinics ; Dentists ; Esthetics, Dental ; Humans ; Prosthesis Coloring ; instrumentation ; Spectrophotometry ; instrumentation ; Tooth

OBJECTIVETo quantitatively characterize vortex flow in patients with early myocardial ischemia by echocardiography using vector flow mapping (VFM) and explore a new diagnostic index of early myocardial ischemia.

METHODSThis study was conducted among 105 patients with suspected angina pectoris, who were free of a previous cardiac history with a normal ejection fraction. Patients without significant coronary artery stenoses constituted the control group (n=49) and those with significant coronary artery stenoses (n=56) constituted the early myocardial ischemia group. All the patients underwent conventional ultrasonic inspection and VFM. The velocity vector and vorticity were estimated by VFM. The vortex parameters including vortex flow, radius, diameter, area and vortex relative strength index were measured.

RESULTSNo significant differences were found in the vortex parameters including the vortex flow, radius, diameter or area between the two groups (P>0.05), but vortex relative strength index was significantly lower in early myocardial ischemia group (23.68∓11.66 vs 20.20∓6.29, P<0.05).

CONCLUSIONVFM is feasible for quantitative evaluation of left ventricular vorticity in healthy individuals and patients with early myocardial ischemia, and the vortex relative strength index may serve as a novel index for the diagnosis of early myocardial ischemia.

Aged ; Case-Control Studies ; Echocardiography ; Female ; Humans ; Male ; Middle Aged ; Myocardial Ischemia ; diagnostic imaging ; physiopathology ; Stroke Volume ; Ventricular Dysfunction, Left ; diagnostic imaging ; physiopathology

OBJECTIVETo observe the Chinese herbal medicine Selaginella-induced radiosensitization of terminal nasopharyngeal carcinoma (NPC).

METHODSTotally 180 patients with NPC were divided equally into 3 groups with the same radiotherapeutic protocols. The patients in group A received radiotherapy alone, those in group B were given daily Selaginella (30 g) prepared into 50 ml decoction during the entire course of radiotherapy, and those in group C had Selaginella 30 g daily in the late course of radiotherapy.

RESULTSThe complete remission rate of nasopharyngeal primary lesions in groups B and C was significantly higher than that in group A, with also significantly higher complete remission rates of the cervical lymph nodes. The acute toxicity of the skin and mucous membrane was milder in the latter two groups, but the differences were not significant.

CONCLUSIONSelaginella may induce radiosensitization for terminal NPC and does not increase the acute toxicity of radiotherapy.

Adult ; Carcinoma, Squamous Cell ; drug therapy ; radiotherapy ; Combined Modality Therapy ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Humans ; Male ; Middle Aged ; Nasopharyngeal Neoplasms ; drug therapy ; radiotherapy ; Phytotherapy ; Radiation-Sensitizing Agents ; therapeutic use ; Selaginellaceae ; chemistry ; Treatment Outcome

A cDNA fragment locating at the putative envelop protein 2(E2) region of GBV-C/HGV fused with Schistosoma japonicum, glutathione S-transferase(GST) was amplified with PCR from plasmid pGEX-E2. The amplified DNA fragment was inserted into plasmid pGEX-5X-1, at the downstream of the coding sequences of GST, in the same reading frame with the gene of GST. The fusion gene fragment of GST-E2 was amplified with PCR, using the recombinant plasmid pGEX-5X-1-E2 as the template. The amplified 1324 bp DNA fragment of GST-E2 was inserted into Pichia pastoris expression vector pPIC9K in reading frame with alpha-factor secreting signal peptide. The plasmid pPIC9K-GST-E2 was transformed into Pichia pastoris GS115 with electroporation. The transformants (His+ Muts) were selected and induced to express the 54kD GST-E2 fusion protein, which could be specially recognized by both the antisera directed against E2 and against GST. The GST-E2 fusion protein was purified with Sepharose 4B glutathione affinity chromatography to a purity of 95%. The expression was optimized to achieve the highest expression level of GST-E2 fusion protein which was accumulated up to 50% of total proteins in the culture supernatant. The GST-E2 protein derived from the recombinant Pichia pastoris was proved possessing antigenicity and high specificity by ELISA, probed with sera from the patients infected by GBV-C/HGV.
Animals ; Antigens, Viral ; genetics ; immunology ; isolation & purification ; GB virus C ; genetics ; immunology ; Gene Expression ; Genetic Engineering ; Glutathione Transferase ; genetics ; Hepatitis Antibodies ; blood ; immunology ; Humans ; Pichia ; Recombinant Fusion Proteins ; genetics ; immunology ; isolation & purification ; Schistosoma japonicum ; enzymology ; Viral Envelope Proteins ; genetics ; immunology ; isolation & purification