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25 December 2015, Volume 24 Issue 6 Previous Issue    Next Issue

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The impact of S.gordonii on P. gingivalis on the form of biofilm ZHANG Dong-mei, LIU Jing-bo, PAN Ya-ping,PAN Jia-yu, XU Qiu-fang. 2015, 24 (6):  641-644.  Abstract ( 347 )   PDF (708KB) ( 422 )   PURPOSE To investigate the impact of S.gordonii on the ultrastructure of P. gingivalis biofilm and on the amount of P. gingivalis in biofilm. METHODS P. gingivalis and/or S.gordonii grew on the culture slides to form single P. gingivalis biofilm and heterotypic biofilm of P.gingivalis-S.gordonii. Then the ultrastructure of the 2 kinds of film were examined by scanning electron microscope, and the amount of P. gingivalis in the biofilm was detected by qPCR. Statistical analysis was performed using pair t test with SPSS 13.0 statistical package. RESULTS At 72 h, the amount of heterotypic biofilm was much more than that of the single P. gingivalis biofilm. Moreover, the structure of the heterotypic biofilm was more regular and with more pore space compared to the single P. gingivalis biofilm. Compared to single P. gingivalis biofilm, the amount of P. gingivalis in heterotypic biofilm was 5.4, 3.8 and 4.4 fold at 24, 48 and 72 h, respectively.CONCLUSIONS The growth of P. gingivalis was promoted by S. gordonii in the form of heterotypic biofilm compared to single P. gingivalis biofilm. References | Related Articles | Metrics

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Influence of the root canal instrumentation size on the disinfection of intracanal microbe by Er:YAG laser XU Xue-Song, ZHU Ya-qin. 2015, 24 (6):  645-651.  Abstract ( 224 )   PDF (1189KB) ( 308 )   PURPOSE To evaluate the influence of different root canal instrumentation size on disinfection of intracanal microbe of dental root canal. METHODS 368 extracted human anterior teeth with single straight root were randomly divided into 8 groups of 46 roots in each. They were instrumented with K3 Ni-Ti files as follows: group A1 and group B1(#25/0.06), group A2 and group B2(#30/0.06), group A3 and group B3(#35/0.06), group A4 and group B4(#40/0.06). After being prepared and sterilized by autoclaving, group A was inoculated with Enterococcus faecalis, and group B was inoculated with Candida albicans. All groups were irrigated with Er:YAG laser combination of 3% NaOCl, 17% EDTA and 0.9% saline, and then the numbers of microbe on the surface of root canal walls were counted after the treatment, the absolute reduction of counting colony forming units(CFUs) and the relative residual rate of CFUs in the individual group was determined. The Date was analyzed with GraphPad Prism 5.02 software package by one-way analysis of variance. RESULTS Levels of disinfection on E.faecalis and C.albicans increased when root canals were enlarged; #40/0.06 showed the best disinfection, #35/0.06 showed a significantly better disinfection than #30/0.06 and #25/0.06. Substantial reduction of microbe was obtained in #35/0.06 and #40/0.06 compared with #25/0.06 and #30/0.06(P＜0.05).CONCLUSIONS Within the root canal size of #25/0.06-#40/0.06, under the conditions of Er:YAG laser combination of 3% NaOCl, 17% EDTA and 0.9% saline, it was concluded that the reduction of E.faecalis and C.albicans of the anterior straight root canals could be predicted by increasing the root canal instrumentation size large than #30/0.06. References | Related Articles | Metrics

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The effect of bacteria reaction time on corrosion properties of Ni-Cr alloys pretreated with different proteins QI Han-quan, ZHANG Song-mei, QIAN Chao, ZHENG Yuan-li. 2015, 24 (6):  652-659.  Abstract ( 189 )   PDF (1747KB) ( 290 )   PURPOSE To evaluate the corrosion properties of absorbed protein on the surface of NiCr alloys, and provide experimental base for corrosion resistance of dental casting alloys. METHODS NiCr alloy specimens were divided into 3 groups: one group was exposed to the artificial saliva(control group), and the other 2 groups were exposed to the artificial saliva with 1% bovine serum albumin(BSA), or 0.22% lysozyme(LSZ). Group of BSA and group of LSZ were the experimental group. Specimens in 3 groups were cultured in solution of Streptococcus mutans for 12 h, 24 h, 36 h and 48h, and investigated with electrochemical impedance spectroscopy measurement(EIS) and potentiodynamic polarization measurement(POT) to determine the corrosion resistance of the alloys. The data was analyzed with SPSS 17.0 software package. RESULTS The results indicated that the corrosion resistance of both BSA group and LSZ group were higher than that of the control group (P<0.05) and LSZ group was superior to BSA group cultured in the solution of Streptococcus mutans for 12 h. When cultured for 24 h, the corrosion resistance of BSA group and LSZ group had no significant difference (P>0.05), but was still higher than that of the control group. After 36 h culture time, the control group and the BSA group had no statistical difference in corrosion resistance （P>0.05), while the LSZ group had the poorest corrosion resistance. When the culture time extended to 48 h, the control group had a better corrosion resistance compared with the BAS group and the LSZ group(P<0.05), but BSA group had displayed lower corrosion properties than LSZ group. The potentiodynamic polarization curve and electrochemical impedance spectroscopy had similar results.CONCLUSIONS The adhesion of BSA and LSZ on the surface of the NiCr alloys in the early time could effectively inhibit the corrosive effect of Streptococcus mutans. The LSZ had better effect than BSA. With the continuing role of bacteria and the consumption of the absorb protein, the corrosion resistance of NiCr alloys toward Streptococcus mutans becomes lower than the alloys without absorb protein, which demonstrated that the adhesion of protein would change the surface structure of NiCr alloys and BSA had a greater effect. References | Related Articles | Metrics

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A comparative assessment of mechanical property between lingual and labial archwires using three-dimension finite element method HE Song, CHEN Zhou-yan, YANG Si-wei, HUANG Yue. 2015, 24 (6):  660-666.  Abstract ( 212 )   PDF (2586KB) ( 322 )   PURPOSE The purpose of this study was to investigate the mechanical property of lingual and labial archwires by using finite element method. METHODS A three-dimensional finite element model including three maxillary left incisors of the 0.022-inch Dentaurum Discovery labial and Ormco 7th Generation lingual brackets was constructed and threaded with corresponding labial and lingual archwires. Then the arch wire’s mechanical property in different materials, sizes and space between brackets were analyzed. RESULTS The load deflection curve of lingual archwire was similar to labial archwire at the same distance of brackets and mainly determined by the characters of archwire. The effects of the type of wire alloy were greater than dimension but less than the coordination of the two: the load value of lingual archwire increased when archwire size increased (the load value of 0.019 × 0.025 inch stainless steel wire was about 1.46 times as bigger as 0.017 × 0.025 inch one),but this change was less than the material of archwire brought(the load value of stainless steel was about 2.73 times as bigger as the same size of titanium-nickel wire),and was less than the coordination of the two(the load value of 0.019 × 0.025 inch stainless steel wire was about 3.5 times as bigger as 0.017 × 0.025 inch titanium-nickel wire),the force of the lingual side was larger than the labial side at the same conditions, when the distance of brackets increased ,both of them decreased gradually(the force loading on 10 mm, 12 mm and 14 mm was about 2.42, 1.59 and 1.33 times as bigger as on 16 mm , respectively), faster in the early, later became stabilized.CONCLUSIONS Lingual archwire should be in smaller diameter, lower stiffness than labial archwire. In choosing arch wire clinically, the material of arch wire should be considered first, followed by size and coordination of the two, meanwhile the distance of brackets should also be considered. References | Related Articles | Metrics

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Effects of PRF and released three growth factors on migration of rat adipose tissue-derived stem cells GAO Jie, WANG Ming-guo, YANG Shuai, LI Xiu-mei, YANG Shi-mao, LI Xue. 2015, 24 (6):  667-673.  Abstract ( 222 )   PDF (1957KB) ( 226 )   PURPOSE To analyze the effects of PRF and released three growth factors on migration of rat adipose tissue-derived stem cells and to investigate the mechanism of migration. METHODS The inguinal adipose tissue of rat was excised at aseptic condition to obtain primary ADSCs by enzyme digestion. Multi-directional differentiation was used to identify the ADSCs. PRF membrane was acquired through one time centrifuge. The cell migration was examined by Transwell assay and wound healing assay. The mRNA expression of MMP2 and MT1-MMP was tested by real-time PCR. Statistical analysis was performed using SPSS 13.0 software package. RESULTS Cell migration test showed that the migration of rat ADSCs in PRF group were significantly higher than those in the negative group（P＜0.05） and inhibitor group（P＜0.05）. The ADSCs migration effects in three growth factors group at different concentrations showed significant difference（P＜0.05）. Real-time PCR showed that gene expressions of MMP2 and MT1-MMP were significantly higher in PRF group than control group (P＜0.05). PCR showed that gene expressions of MMP2 and MT1-MMP were significantly higher in three growth factors group than control group (P＜0.05). CONCLUTIONS: PRF and three growth factors consistently enhanced the migration of rat ADSCs in a dose-response manner. The migration increase of rat ADSCs may be associated with the up-regulation of MMP2 and MT1-MMP gene expression. References | Related Articles | Metrics

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Dental pulp stem cells modified by HIF-1α can differentiate into blood vessels FU Hong-hai, LI Peng-chong, ZHAO Li, ZUO Jin-hua. 2015, 24 (6):  674-678.  Abstract ( 273 )   PDF (743KB) ( 243 )   PURPOSE To investigate the method of differentiating dental pulp stem cells (DPSCs) modified by HIF-1α into blood vessels. METHODS DPSCs were extracted from teeth samples from 20 patients and were identified by Strol-1 and CD146. DPSCs were divided into experimental group and control group according to DPSCs were modified by HIF-1α not or. HIF-1α-mRNA expression was detected by RT-PCR. HIF-1α, VEGF, SDF-1, Ang-2 and PDGF expression were detected using Western blot in different time after culture for 1 d, 4 d, 7 d and 14 d. Statistical analysis was carried out with SPSS 16.0 software package. RESULTS Most DPSCs appeared round, oval under phase-contrast microscopy. CD146 and Strol-1 showed green fluorescence. HIF-1α and HIF-1α-mRNA expression became higher with time passing and the difference was statistically significant (P＜0.05). Compared with the control group, HIF-1α protein and mRNA increased obviously in the experimental group 1d, 4d, 7d and 14d after transfection, and the difference was statistically significant (P<0.05). The level of VEGF, SDF-1, Ang-2 and PDGF in the control group was changed unconspicuously, and the expression was not different at different times (P>0.05). The level of VEGF, SDF-1, Ang-2 and PDGF in the exprimental group increased, and the difference was statistically significant between different time points(P<0.05). Compared with the control group, the level of VEGF, SDF-1, Ang-2 and PDGF in the experimental group was higher 1 d, 4 d, 7 d and 14 d after transfection, respectively, and the difference was statistically significant(P<0.05).CONCLUSIONS DPSCs modified by HIF-1α gene can successfully induce vascular differentiation in vitro, which provides foundation for further angioplasty. References | Related Articles | Metrics

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Sintering behavior of tooth-like yttria-stabilized tetragonal zirconia polycrystal by adding rare-earth oxide GAO Yan, ZHANG Fu-qiang, GAO Jian-hua. 2015, 24 (6):  679-686.  Abstract ( 185 )   PDF (2449KB) ( 274 )   PURPOSE To investigate the influence on the sintering densification, microstructure and transformation behavior of tooth-like yttria-stabilized tetragonal zirconia polycrystal by adding rare-earth oxide as colorants. METHODS Six kinds(S1,S2,S3,S4,S5,S6) of tooth-like yttria stabilized tetragonal zirconia polycrystal(Y-TZP)were made by introducing internal colorating technology, the relative density of sintered specimens was determined by the Archimedes method. Scanning electron microscope (SEM) was used to examine the surface morphology and determine the grain size. The phase identification of sintered samples was carried out by X-ray diffractometer. RESULTS The relative density of the six kinds of tooth-like yttria stabilized tetragonal zirconia polycrystal were over 98%，through SEM images of the cross-sectional surfaces, the grain size of the six kinds of sintered composites were observed in a wide range from 100 nm to 300 nm, a second phase was not detected in the grain boundaries. The diffraction peaks of the main phase were observed as tetragonal phase.CONCLUSIONS Tooth-like yttria-stabilized tetragonal zirconia polycrystal was acquired with better mechanical property by adding rare-earth oxide as colorants, and was available for clinical application. References | Related Articles | Metrics

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The measurement of thermal expansion coefficient of Co-Cr alloy fabricated by selective laser melting TIAN Xiao-mei, ZENG Li, WEI Bin, HUANG Yi-feng. 2015, 24 (6):  687-689.  Abstract ( 255 )   PDF (369KB) ( 381 )   PURPOSE To investigate the thermal expansion coefficient of different processing parameters upon the Co-Cr alloy prepared by selective laser melting (SLM) technique, in order to provide technical support for clinical application of SLM technology. METHODS The heating curve of self-made Co-Cr alloy was protracted from room temperature to 980℃ with DIL402PC thermal analysis instrument, keeping temperature rise rate and cooling rate at 5 K/min, and then the thermal expansion coefficient of 9 groups of Co-Cr alloy was measured from 20℃ to 500℃ and 600℃. RESULTS The 9 groups thermal expansion coefficient values of Co-Cr alloy heated from 20℃ to 500℃ were 13.9×10-6/K,13.6×10-6/K,13.9×10-6/K,13.7×10-6/K,13.5×10-6/K,13.8×10-6/K,13.7×10-6/K,13.7×10-6/K,and 13.9×10-6/K, respectively; when heated from 20℃ to 600℃, they were 14.2×10-6/K,13.9×10-6/K,13.8×10-6/K,14.0×10-6/K,14.1×10-6/K,14.1×10-6/K,13.9×10-6/K,14.2×10-6/K, and 13.7×10-6/K, respectively.CONCLUSIONS The results showed that the Co-Cr alloy has good matching with the VITA VMK 95 porcelain powder and can meet the requirement of clinic use. References | Related Articles | Metrics

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The influence of autoclave sterilization on surface characteristics and cyclic fatigue resistance of 3 nickel-titanium rotary instruments LI Xiang-fen, ZHENG Ping, XU Li, SU Qin. 2015, 24 (6):  690-695.  Abstract ( 211 )   PDF (1272KB) ( 393 )   PURPOSE To investigate the effects of autoclave sterilization on surface characteristics and cyclic fatigue resistance of 3 types of nickel-titanium rotary instruments (K3, Mtwo, ProTaper). METHODS Three brands of NiTi rotary endodontic instruments of the same size (tip diameter 0.25 mm and constant 0.06 taper) were selected: K3, Mtwo and Protaper (F2). 24 instruments for each brand were used to evaluate the effects of autoclave sterilization on inner character in the as-received condition and after subjection to 0, 1, 5, and 10 sterilization cycles (6 for each group). Time to fracture (TtF) from the start of the test to the moment of file breakage and the length of the fractured fragment were recorded. Means and standard deviations of TtF and fragment length were calculated. The data was analyzed with SPSS13.0 software package. Another 12 NiTi rotary instruments for each brand were used, 6 subjected to 10 autoclave sterilization cycles and the other as control. Scanning electron microscope was used to observe the changes in surface topography and inner character. RESULTS：For cyclic fatigue resistance, when sterilization was not performed, K3 showed the highest value of TtF means and ProTaper the lowest. The differences between each brand were statistically significant (P<0.05).When disinfection was performed, K3 brand showed greater fatigue resistance in comparison with the control when autoclave sterilization cycled 5 times and 10 times. The difference between 10 cycles of sterilization and the control was statistically significant (P<0.05); ProTaper brand showed significantly greater fatigue resistance in all the disinfected groups compared with the control (P<0.05) and 5 cycles of sterilization led to the greatest increment; The fatigue resistance of Mtwo brands increased with sterilization cycles and the difference between 5/10 cycles and the control were statistically significant (P<0.05).For surface characteristics, under scanning electron microscope, surface and inner imperfections in all instruments were intensified greatly after 10 cycles of sterilization.CONCLUSIONS Cycle fatigue resistance is different among instruments of different brands. Autoclave sterilization may increase fatigue resistance of the 3 brands. Autoclave sterilization may increase the surface roughness and inner defects in cross section. References | Related Articles | Metrics

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Experimental study on the retentive force of cobalt-chromium alloy, pure titanium and vitallium cast clasps in the simulated 3-year clinical use YAN Hai-xin,, ZHAO Yan-bo, QIN Li-mei,, ZHU Hai-ting,, WU Lin,. 2015, 24 (6):  696-701.  Abstract ( 676 )   PDF (888KB) ( 177 )   PURPOSE To investigate the changes of retentive force of cobalt-chromium alloy, pure titanium and vitallium cast clasps in the simulated 3-year clinical use. METHODS Fifteen metal abutment crowns made of No.QT800-2 nodular cast iron were used in the test. Five clasps from each of the following alloys: cobalt-chromium alloy, pure titanium and vitallium were fabricated. The undercut depth was 0.25 mm. A masticatory simulator was used to cycle the clasp on and off the metal abutment crown 5000 times, simulating 3-year clinical use. Retentive force was measured 11 times during this process. SPSS13.0 software package was used to analyze the results. Casting defects were observed using X-ray non destructive testing (X-ray NDT) before cyclic test. Surface characteristics were qualitatively evaluated using scanning electron microscope (SEM) before and after cyclic test. RESULTS The results indicated that there were significant differences (P=0.000) in the retentive force of the 3 groups before and after the cyclic test. The highest retentive force was recorded in the vitallium clasps, and the lowest retentive force was measured in the pure titanium clasps. The results of X-ray NDT depicted the typical casting defect seen at the end of the connector. SEM examination revealed that no evidence of pores and cracks in the inner surfaces of the 3 groups was found before cyclic test. Wear was evident in the inner surfaces of the 3 groups but none of the clasps exhibited any evidence of cracks after cyclic test through SEM examination.CONCLUSIONS In this in vitro test, vitallium clasps show the best retentive force in the 3 groups before and after 5000 cycles at 0.25 mm undercut depth. Cobalt-chromium alloy and vitallium clasps can maintain ideal retentive force at 0.25mm undercut depth in the long-term use. Wear may be one of the reasons for the loss of retentive force of clasps in the cyclic test. References | Related Articles | Metrics

Clinical Study

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Application of one-piece implant-supported detachable telescope retained fixed bridge in edentulous cases WANG Qiao-na, LI Ming, QIU Jing, ZHANG Xiao-zhen, WU Zi-qiang, CHEN Dong-lei, XU Jing-ming, TANG Chun-bo 2015, 24 (6):  702-707.  Abstract ( 348 )   PDF (1364KB) ( 333 )   PURPOSE To evaluate the clinical effectiveness of one-piece implant-supported detachable telescopic fixed bridge in edentulous patients. METHODS Seventeen patients were treated with one-piece implant-supported detachable telescopic fixed bridge. A total of 18 prostheses were fabricated with 8 in the upper jaws and 10 in the lower jaws.Fixed bridges retained by telescopic crowns were used as final prostheses, with milling titanium or all-ceramic abutments as primary crowns, gold-electroforming crowns as secondary crowns. Surveys about clinical and radiographic examination, satisfaction and prosthetic complications were conducted after 3 months,1 year, 2 years, 3 years after final rehabilitation. Data analysis was performed using SPSS 17.0 software package.RESULTS Radiography showed stable bone levels for all implants except 2 implants, which were observed slight marginal bone resorption. The results of one-way ANOVA showed that no significant difference in modified plaque index or modified sulcus blooding index was found during the follow-up period (P>0.05). The probing attachment level deteriorated by 1.5 mm during the first 3 years (P<0.05). Eighteen restoration provided sufficient fixation and stability. Two porcelain fractures occured but had no influence on restoration. The patients were highly satisfied with the outcomes. The frequency of prosthetic maintenance per patient per year was 0.11.CONCLUSIONS One-piece implant-supported detachable telescopic fixed bridge is an effective method with satisfactory long-term aesthetic and stable outcomes in edentulous patients. References | Related Articles | Metrics

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Effect of periodontal initial therapy on the amount of SFRP1 in gingival crevicular fluid in patients with periodontitis WANG Lu, ZHOU Mei-lu, XU Chun-jiao, QIU Xi-li, XU Wen-hua, WU Kai-yue, CHI Yu-tan. 2015, 24 (6):  708-711.  Abstract ( 303 )   PDF (478KB) ( 237 )   PURPOSE To detect the change of secreted frizzled-related protein-1（SFRP1） in gingival crevicular fluid during periodontal initial treatment and explore the relationship between SFRP1 and the activity of chronic periodontitis. METHODS Twenty-two patients with moderate to severe periodontitis were selected, and 5 healthy volunteers were enrolled into the study as control group. The bleeding index(BI),periodontal probing depth(PD)and clinical attachment loss(CAL) were recorded at 1 week after supragingival scaling, one month after subgingival scaling. Gingival crevicular fluid (GCF) was collected at 1 week after supragingival scaling, one week after subgingival scaling, one month after subgingival scaling. The level of SFRP1 in GCF samples was detected by ELISA. SPSS19.0 software package was used for data processing. RESULTS The amount of SFRP1 in GCF of moderate to severe periodontitis group was (40.80±4.85) pg, and that of normal control was (33.42±2.24) pg at 1 week after supragingival scaling. The amount of SFRP1 in GCF was significantly higher in moderate to severe periodontitis compared to normal control group (P<0.05). In moderate to severe periodontitis group, the amount of SFRP1 in GCF significantly increased at l week after subgingival scaling (45.99±5.23) pg compared to 1 week after supragingival scaling and 1 month after subgingival scaling (36.92±4.00) pg (P<0.05); There was significant decrease in the amount of SFRP1 in GCF at 1 month after subgingival scaling,compared to 1 week after supragingival scaling and l week after subgingival scaling (P<0.05).CONCLUSIONS The BI, PD in the periodontitis groups were significantly improved at 1 month after initial therapy,and the amount of SFRP1 in GCF changed with different periodontal inflammation state． References | Related Articles | Metrics

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Optimal sequence algorithm of divided period appointment consultation service sequence for re-visiting patients in the department of stomatology HU Yuan, JIN Wen-zhong, LU Yao, HU Xiao-feng, WU Zheng-yi. 2015, 24 (6):  712-715.  Abstract ( 250 )   PDF (513KB) ( 254 )   PURPOSE An optimal sequence algorithm model of divided period appointment consultation service was built through optimal sequence algorithm. METHODS Re-visiting patients in the department of stomatology in a tertiary hospital were enrolled as the research objects in this study. Information about the diagnose term of common diseases, tooth positions treated, doctor's consultation hours were collected. After calculating the mean consultation hours of each disease based on the statistical analysis, the appointment consultation service sequence of re-visiting patients in the department of stomatology was optimized in accordance with the rule of "providing priority service to those requiring short consultation hours" by referencing to the theoretical model of parallel machine. RESULTS The total waiting hours of patients after optimizing the appointment consultation sequence was decreased by 35.1%.CONCLUSIONS Optimal sequence algorithm can optimize divided period consultation sequence, effectively shorten waiting hours and improve patients' medical experience. References | Related Articles | Metrics

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Subsequent therapy for infantile hemangiomas after discontinuation of oral propranolol TAI Mao-zhong, LIU Xue-jian, QIN Zhong-ping, GE Chun-xiao, LI Ke-lei, CHEN Tao. 2015, 24 (6):  716-720.  Abstract ( 433 )   PDF (1226KB) ( 221 )   PURPOSE To summarize the subsequent therapy experiences for infantile hemangiomas after discontinuation of oral propranolol treatment, and explore the relationships between clinical interventions and types of infantile hemangioma. METHODS In this retrospective study from January 2010 to May 2014, a total of 137 infants with hemangiomas undergoing sequential therapy after oral propranolol treatment. There were 41 males and 96 females. The median age was 16 months, ranging from 14 to 25 months. After oral propranolol treatment, the outcomes were evaluated to be grade Ⅲ in 74 cases, grade Ⅱin 62 cases and grade Ⅰ in 1 case. The types were papula (n=31), telangiectasis (n=11), plump (n=74), deep (n=12) and compound (n=9). The primary sites were 3 cases in scalp, forty-nine in face, thirty-three in trunk, thirty-eight in extremities. Cutis laxa presented in 45 cases, and parenchyma hypertrophy presented in 80 cases. Sequential therapy were performed including laser therapy for 38 cases, intralesional Pingyangmycin injection for 63 cases, and plastic surgery for 16 cases. The efficacy was re-evaluated on a 4-level scale, combined with evaluations of scar, cutis laxa or pigment alteration. SPSS18.0 software package was used for statistical analysis. RESULTS Chi-square test showed significant differences between 5 types in occurrence of cutis laxa and parenchyma hypertrophy (χ2=28.458,68.276, P＜0.01). After a follow-up of 6 months to 4 years, the outcomes were evaluated to be grade IV in 122 cases, grade Ⅲ in 15 cases, without grade Ⅱor gradeⅠ case. There were significant differences in 5 types of infantile hemangiomas before and after sequential therapy( H=53.445，9.941, 120.324, 17.000, 18.899, P＜0.01). Postoperative scar was presented in 2 cases around to joints, and mild pigment alteration was noticed in 2 cases after intralesional Pingyangmycin injection.CONCLUSIONS Cutis laxa and parenchyma hypertrophy may be more likely present in infantile hemangiomas after oral propranolol treatment. Laser therapy is recommended for patients with papula or telangiectasis, when necessary, intralesional Pingyangmycin injection should be combined. Intralesional Pingyangmycin injection should be the first choice for plump or compound type，whereas surgery should be executed in patients with deep type or other plump type complicated by severe hyperplasia, after which combined intralesional Pingyangmycin injection may be required for postoperative superficial residues. References | Related Articles | Metrics

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Clinical study of sinus elevation by hydraulic and implant placement followed by bone graft simultaneously YANG Yan-zhong, TIAN Xiao-hua, LI Xiao-feng, GONG Zheng-wei. 2015, 24 (6):  721-725.  Abstract ( 290 )   PDF (1889KB) ( 338 )   PURPOSE To evaluate the clinical results and technique of sinus membrane hydraulic elevation followed by bone graft and implant placement simultaneously. METHODS Twenty-five patients were involved in the study (male:15, female: 10, age: 40-62 yrs). The mean residual ridge was (4.25±1.12) mm. Clinical examination were performed and radiographs were taken to evaluated the outcomes. RESULTS The mean elevated height was (8.50±2.12) mm and 25 implants were placed. Only one implant was lost due to infection 3 weeks after operation because of diabetes. Only minor complications were observed postoperatively in the remaining patients. Twenty-four patients were satisfactorily restored with the follow-up period of 12～18 months.CONCLUSIONS The technique of sinus membrane hydraulic elevation followed by bone graft and implant placement simultaneously displays minor complication, minimal discomfort and excellent success rate. References | Related Articles | Metrics

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Analysis of the distance from maxillary sinus base wall to alveolar crest of first maxillary molar with age DONG Zheng-jie, XU Kan. 2015, 24 (6):  726-728.  Abstract ( 314 )   PDF (701KB) ( 210 )   PURPOSE To measure the height of the maxillary first molar alveolar crest in different age groups. METHODS A total of 288 patients were divided into 3 groups: young age group (18-34 years), middle age group (35-59 years) and old age group (above 60 years). They were selected to be scanned by cone-beam computed tomography (CBCT), and the height of the first maxillary molar alveolar crest was measured though Kavo eXam Vision software. The data was analyzed with SPSS16.0 software package for Student’s t test. RESULTS In young age group, the height of the maxillary first molar alveolar crest was (9.08±3.70) mm; middle age group, the height was (10.66±3.99) mm; and in old age group, the height was (12.40±4.54) mm. There was no significant difference between males and females in each group, but there were significant differences between different age group in the height of the maxillary first molar alveolar crest.CONCLUSIONS The height of the maxillary first molar alveolar crest is increasing with the increase of age, but there is no difference between males and females. For patients undergoing implantation in maxillary posterior region, CBCT should be performed to determine the height of alveolar crest and anatomy of the maxillary sinus, especially for young patients. References | Related Articles | Metrics

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Detection of miR-155, miR-146a in PBNCs and tissues from patients with oral lichen planus LIANG Xue-yi, HU Jing-yu, ZHOU Gang. 2015, 24 (6):  729-734.  Abstract ( 256 )   PDF (849KB) ( 308 )   PURPOSE To investigate the miRNA (including miR-155, miR-146a and miR-146b) expression in peripheral blood mononuclear cells (PBNCs) or lesions tissues in oral lichen planus (OLP) patients and healthy controls and the relationship between miRNA and OLP clinical features. METHODS The expression of miRNA（miR-155, miR-146a and miR-146b）was assessed by quantitative fluorescent PCR in peripheral blood cells or lesions tissues in OLP patients and healthy controls. U6 was used as reference gene. Statistical analysis was performed with SPSS17.0 software package. RESULTS Real-time PCR showed that the expression of miR-155 in OLP PBNCs was significantly higher than that in controls, miR-155 expression in OLP lesions tissues was 7.0 times higher than that of PBMCs. Correlation analysis showed that the level of miR-155 expression in PBMCs was positively correlated with REU score(correlation coefficient R=0.887, P<0.01). There was no significant difference in miR-146a and miR-146b expression in PBMCs between OLP and control group. On the contrary, the miR-146a expression in OLP lesions tissues was significantly upreguated than that in control group (P=0.003).CONCLUSIONS The results indicated that miR-155 and miR-146a might play important roles in the pathogenesis of OLP and OLP is likely a chronic inflammatory disease characterized by local inflammation. References | Related Articles | Metrics

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The impact of smoking on human beta defensin 2,3 in gingival crevicular fluid and gingival tissue of patients with chronic periodontitis FAN Yun, CHEN Dong, YE Xin, YU Fang-fang, LI Wei. 2015, 24 (6):  735-738.  Abstract ( 188 )   PDF (675KB) ( 286 )   PURPOSE To study the impact of smoking on human beta defensin 2,3 expression in gingival crevicular fluid and gingival tissue of patients with chronic periodontitis. METHODS The study subjects were divided into chronic periodontitis with smoking and without smoking. Enzyme linked immunosorbent assay (ELISA) was used to detect the concentration of hBD2,3. RT-PCR was used to detect the mRNA expression of hBD2,3. SPSS17.0 software package was used for statistical analysis. RESULTS In GCF, the expression level of hBD2,3 in the smoking group was significantly lower than that in the non-smoking group. The mRNA expression level of hBD2,3 in the smoking group was weakened compared with that in the non-smoking group.CONCLUSIONS Smoking can change the expression of hBD2,3 in both GCF and gingivae, which indicates that smoking may have a negative effect on the immune defense system of the periodontal host. References | Related Articles | Metrics

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Clinical effect of premolar extraction with high torque self-locking appliances CHEN Shuang-xi, TANG Guo-hua, JIANG Yu-nan, GU Yong-jia, ZHANG Ting, GAO Mei-qin. 2015, 24 (6):  739-742.  Abstract ( 843 )   PDF (584KB) ( 262 )   PURPOSE To analyze the clinical effect of extraction correction of patients with maxillary protrusion by using Damon high torque appliances. METHODS Forty patients with extraction of four first premolars due to orthodontic treatment were selected. They had protrusion of maxilla and were randomly divided into two groups. Both arches of Damon group were treated with Damon high torque appliances and MBT group were corrected with traditional MBT straight wire appliance; patients in two groups received sliding mechanics for adduction of upper anterior teeth. Cephalometric radiophotographs were analyzed before（T0）and after adduction of upper anterior teeth（T1）. The difference between the two groups was analyzed with SPSS15.0 software package. RESULTS The upper incisors showed a more retruded position in the two groups at T1,although they showed a similar amount in both groups. The backward movement of upper lip was 2.31mm in Damon group, which was significantly less than that of 2.81mm in MBT group(P＜0.05). No significant difference in the first molar mesialization was detected between Damon group(2.33 mm) and MBT group(2.36mm) (P＞0.05). For anterior teeth retraction, nasolabial angle (NLA) in MBT and Damon group were 107.44°and 106.33°, increase of NLA in MBT group was 9.17°,which was significantly larger than that of 7.22°in Damon group (P＜0.05). U1-MxP in MBT and Damon were 110.61°and 114.11°. U1-MxP decreased 12.06°in MBT group, while significant change was deteced in Damon group of 7.61°(P＜0.05).CONCLUSIONS Application of Damon high torque appliances in extraction treatment of maxillary protrusion patients yielded better control of the labial crown torque of anterior teeth, and avoided excessive lingual inclination of anterior teeth compared with MBT in adduction of upper anterior teeth. References | Related Articles | Metrics

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Clinicopathologic analysis of cervical lymph node metastasis in 708 patients with oral squamous cell carcinoma LI Xue-jie, ZHANG sheng, WU Han-jiang, ZHU Zhao-fu, LIU Jin-bing. 2015, 24 (6):  743-747.  Abstract ( 708 )   PDF (520KB) ( 515 )   PURPOSE To investigate the characteristics of cervical lymph node metastasis in oral squamous cell carcinoma (OSCC), and the relationship between clinicopathologic factors of OSCC and cervical lymph node metastasis (CLNM). METHODS Clinicopathologic data of 708 patients with OSCC who underwent neck dissection were retrospectively analyzed. The relationship between clinicopathologic factors of OSCC and CLNM was analyzed with univariate analysis and multivariate analysis using SPPPSS19.0 software package. RESULTS The incidence of CLNM of OSCC was 35.6%(252/708), and the incidence of CLNM at each level was：levelⅠ30.7%（149/485）, level Ⅱ33.8% (164/485), level Ⅲ22.5% (109/485), level Ⅳ8.0% (39/485), and levelⅤ4.9% (24/485), respectively. From univariate analysis of the results, age, differentiation degree, depth of invasion, pathological T stage were significantly correlated with CLNM (P＜0.05); while gender, location were not significantly correlated with CLNM (P＞0.05). From multivariate analysis of the results, only differentiation degree, depth of invasion and pathological T stage were significantly correlated with CLNM (P＜0.05). Depth of invasion was probably the most important influential factor for CLNM of OSCC (OR=2.191).CONCLUSIONS There was positive relationship between CLNM and pathological T stage , depth of invasion; while there was negative relationship between CLNM and differentiation degree. Depth of invasion was probably the first influential factor for CLNM of OSCC. References | Related Articles | Metrics

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Effect of 2 methods of occlusion adjustment on occlusal balance and muscles of mastication in patient with implant restoration WANG Rong, XU Xin. 2015, 24 (6):  748-752.  Abstract ( 342 )   PDF (1005KB) ( 270 )   PURPOSE To compare the effect of 2 methods of occlusion adjustment on occlusal balance and muscles of mastication in patients with dental implant restoration. METHODS Twenty patients, each with a single edentulous posterior dentition with no distal dentition were selected, and divided into 2 groups. Patients in group A underwent original occlusion adjustment method and patients in group B underwent occlusal plane reduction technique. Ankylos implants were implanted in the edentulous space in each patient and restored with fixed prosthodontics single unit crown. Occlusion was adjusted in each restoration accordingly. Electromyograms were conducted to determine the effect of adjustment methods on occlusion and muscles of mastication 3 months and 6 months after initial restoration and adjustment. Data was collected and measurements for balanced occlusal measuring standards were obtained, including central occlusion force (COF), asymmetry index of molar occlusal force(AMOF). Balanced muscles of mastication measuring standards were also obtained including measurements from electromyogram for the muscles of mastication and the anterior bundle of the temporalis muscle at the mandibular rest position, average electromyogram measurements of the anterior bundle of the temporalis muscle at the intercuspal position(ICP), Astot, masseter muscle asymmetry index, and anterior temporalis asymmetry index (ASTA). Statistical analysis was performed using Student 's t test with SPSS 18.0 software package. RESULTS Three months after occlusion adjustment, parameters of the original occlusion adjustment method were significantly different between group A and group B in balanced occlusal measuring standards and balanced muscles of mastication measuring standards. Six months after occlusion adjustment, parameters of the original occlusion adjustment methods were significantly different between group A and group B in balanced muscles of mastication measuring standards, but was no significant difference in balanced occlusal measuring standards.CONCLUSIONS Using occlusion plane reduction adjustment technique, it is possible to obtain occlusion index and muscles of mastication’s electromyogram index similar to the opposite side's natural dentition in patients with single unit fix prosthodontics crown and single posterior edentulous dentition without distal dentitions. References | Related Articles | Metrics

Clinical Reports

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Use of extend lateral upper arm free flap for reconstruction of soft tissue defect after resection of oral cancer YANG Xu-dong, WANG Yu-xin, LI wei, WEN Jian-ming, HONG Xiao-wei, HU Qin-gang. 2015, 24 (6):  753-757.  Abstract ( 308 )   PDF (1509KB) ( 232 )   PURPOSE To investigate the clinical outcomes of composite lateral arm free flap to reconstruct soft tissue defect after oral cancer ablation. METHODS Fifteen cases of soft-tissue defects were reconstructed using composite lateral arm free flap from January 2011 to December 2013. Color Doppler ultrasound blood flow detector was used to avoid variation of posterior radial collateral artery (PRCA). Composite flaps were designed according to the direction of PRCA, shape and area of the soft-tissue defect, which were over condylus lateralis humeri, with areas ranged from 4 cｍ×5 cm-11 cm×5 cm and an average vascular pedicle length of 10cm. Primary closure was achieved on all donor sites. RESULTS Fourteen flaps survived while vascular crisis was found in one flap 1 day post operation. The flap was replaced after an invalid salvation. All patients were followed up over 12 months, no recurrence was found. All patients achieved good recovery of morphology and functions with only 2 reporting local numbness of donor sites, which were relieved after 6 months.CONCLUSIONS Composite lateral arm free flap, with consistent anatomy, suitable thickness and reliable blood supply, is a proper method to reconstruct postoperative soft tissue defect of patients with oral carcinoma. References | Related Articles | Metrics

Dental Education

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Evaluation of flipped classroom teaching model in undergraduates education of oral and maxillofacial surgery CAI Ming, CAO Xia, FANG Xiao,WANG Xu-dong, ZHANG Li-li, ZHENG Jia-wei, SHEN Guo-fang. 2015, 24 (6):  758-762.  Abstract ( 203 )   PDF (705KB) ( 383 )   Flipped classroom is a new teaching model which is different from the traditional teaching method. The history and characteristics of flipped classroom teaching model were introduced in this paper. A discussion on how to establish flipped classroom teaching protocol in oral and maxillofacial surgery education was carried out. Curriculum transformation, construction of education model and possible challenges were analyzed and discussed. References | Related Articles | Metrics

Case Reports

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Adenosquamous carcinoma of the parotid gland: report of 1 case and review of the literature CHEN Wei-hua, PEI Jing, ZHUO Xia-yang. 2015, 24 (6):  763-765.  Abstract ( 522 )   PDF (1286KB) ( 292 )   Oral adenosquamous carcinoma is an uncommon highly malignant tumor.We reported a case of adenosquamous carcinoma of the parotid gland in a 61-year-old male patient. We found the tumor was composed of both true squamous cell carcinoma and adenocarcinoma with a significant rate of lymph node metastasis, and the 5-year survival rate is low. References | Related Articles | Metrics

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Soft-tissue osteomas in buccal space: a case report and review of the literatures HAN Yu-min, WANG Yan, GAO Qian-qian, FEGN Xiao-yu, BU Ling-xue, FENG Yuan-yong, SHANG Wei. 2015, 24 (6):  766-768.  Abstract ( 366 )   PDF (942KB) ( 245 )   Osteoma is a benign tumor, which is composed of mature differentiated bone tissue .Osteoma can be central, peripheral or extraskeletal. Extraskeletal osteoma also is called soft-tissue osteoma. Extraskeletal soft-tissue osteoma is exceedingly rare, especially in the oral cavity. This article reported a case with soft-tissue osteomas in buccal space. The histogenesis, differential diagnosis, pathologic type and treatment were discussed. Surgical resection is suggested as the main treatment for this disease. References | Related Articles | Metrics