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    26 October 2016, Volume 32 Issue 10 Previous Issue    Next Issue

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    Application of 3D-printing and CGF in Bilateral Inferior Alveolar Nerve Transposition and Reposition.
    FU Li, SUN Yue, ZHAI Jing-jie, SUN Xiao-lin, ZHOU Yan-min.
    2016, 32(10): 1003-1005.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.001
    Abstract ( 495 )   PDF (1088KB) ( 294 )  
    Inferior alveolar nerve (IAN) transposition is a feasible treatment option for managing severely atrophic mandibles with dental implants. However, the inherent risk is the damage of IAN. In the present study, a case of bilateral IAN transposition and reposition with the combinative application of 3D-printing and CGF was firstly reported to reduce the risks of surgery.
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    Alternative Splicing of CD55 Intron 7 Is Regulated by HnRNP L in Oral Squamous Cell Carcinoma.
    ZHANG Si, LIU Miao-miao, LIU Pei-qi, JIA Rong, GUO Ji-hua.
    2016, 32(10): 1006-1009.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.002
    Abstract ( 420 )   PDF (877KB) ( 269 )  
    Objective: To study the effect of splicing factor hnRNP L on alternative splicing of CD55 intron 7, a new target of hnRNP L in CAL 27 cells. Methods: An exon array data about hnRNP L down-regulation in cells in GEO database was re-analyzed with GEO2R online service. HnRNP L was knocked down by using siRNA in oral squamous cell carcinoma (OSCC) CAL 27 cells. Alternative splicing of CD55 intron 7 was analyzed by RT-PCR. Results: CD55 is a new target of hnRNP L. Knockdown of hnRNP L in CAL 27 cells significantly increased the inclusion of CD55 intron 7.Conclusion: The retention of CD55 intron 7 was regulated by hnRNP L. CD55 was the target of hnRNP L in OSCC cells.
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    Antibiofilm and Antibacterial Mechanism of Porous HAPw/n-ZnO Bone Restorative Material.
    ZHANG Yu-cheng, ZHANG Wen-yun, Bao Fu-kai, YANG Li-dou, Yuan Yan-bo, Chen Qing-hua.
    2016, 32(10): 1010-1014.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.003
    Abstract ( 291 )   PDF (1112KB) ( 458 )  
    Objective: To study the antibiofilm activity and antibacterial mechanism of porous hydroxyapatite whisker (HAPw)/nano zinc oxide (n-ZnO) bone restorative biomaterial. Methods: Staphylococcus aureus, Streptococcus mutans, and Porphyromonas gingivalis biofilm model were established in vitro respectively. Under darkness, biofilm inhibition assay and intracellular reactive oxygen species (ROS) measurement were performed in the same concentration gradient (0-2 mg/mL) of the porous HAPw/n-ZnO material. The scanning electron microscope was employed to analyze the material. Without porous HAPw/n-ZnO, inoculums was used as control. Results: As the material concentration increases, each concentration of porous HAPw/n-ZnO group (1.00, 1.25, 1.50, 1.75, and 2.00 mg/mL) relative to the control (0 mg/mL), three kinds of oral bacteria biofilm formation exhibited a gradual decrease and an increased intracellular ROS level under darkness. The difference was statistically significant (P<0.05). Scanning electron microscopy (SEM) images revealed that the treatment of the material decreased the bacteria adhesion and three kinds of biofilm formation. Composite material group exhibited abnormal bacteria morphology and bacterial cell membrane destruction, which caused the leakage of intracellular contents. Conclusion: Porous HAPw/n-ZnO materials has a certain degree of inhibition under darkness on staphylococcus aureus, streptococcus mutans, and Porphyromonas gingivalis biofilm, and one of its antibacterial mechanism is the formation of reactive oxygen species (ROS).
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    Interaction Effects of Fiber Post Diameter and Ferrule Height on Fracture Resistance of Post-Retained Restorations.
    LI Qing, XU Dong-xuan.
    2016, 32(10): 1015-1019.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.004
    Abstract ( 344 )   PDF (1048KB) ( 298 )  
    Objective: To explore the interaction effects of ferrule height and fiber post dimension on the fracture resistance of endodontically treated teeth. Methods: Sixty endodontically treated incisors were randomly assigned into four groups (n=15), and decoronated at 0 mm, 1 mm, 2 mm, and 3 mm to the proximal cemento-enamel junction (CEJ). The roots were restored using fiber posts with various dimensions. All specimens were subjected to fracture failure tests, loaded with an incremental force at an angle of 45° to the long axis of the roots. Fracture failure loads were recorded and analyzed using two-way analysis of variance (ANOVA), followed by the Tukey's post hoc comparisons. The fracture modes were investigated using fractographic analysis. Results: The interaction effects of ferrule height and post dimension were detected (P=0.006). Post dimension significantly influenced the fracture failure loads of specimens with 0 mm and 1 mm ferrule. No significant difference was found between 2# and 3# posts in 2 mm ferrule, or among all the dimensions of posts in 3 mm ferrule. Increasing of ferrule height decreased the probability of the debonding at the core/dentin interface. Conclusion: The effect of post dimension on fracture resistance decreases with the increasing of ferrule height. Increasing of ferrule height potentially postpones the processing of the ultimate fracture failure.
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    Observation of GFP-labeled 3D-printed Jaw using Laser Confocal Microscopy in Vivo.
    HAN Xiang-zhen, ZHOU Qi-qi, HU Yang, SONG Yan-yan, HE Hui-yu.
    2016, 32(10): 1020-1023.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.005
    Abstract ( 259 )   PDF (1216KB) ( 242 )  
    Objective: To observe GFP-labeled 3D-printed jaw by using laser confocal microscopy in vivo and to provide technical basis for the follow-up function study. Methods: The calcined ceramic powder was made from sheep vertebrae, which was combined with polyvinyl alcohol to form jaw scaffold. Sheep BMSCs were infected by GFP lentivirus and cultured on the scaffold. The scaffold was implanted into sheep jaw defect and observed by confocal laser scanning microscope at different time points. Results: The infection efficiency was about 95.4% detected by flow cytometry. BMSCs could survive for more than 3 months on the scaffold determined by three-dimensional imaging technique using laser scanning confocal microscopy after implantation. Conclusion: Laser scanning confocal microscopy can be used to observe the GFP-labeled 3D-printed jaw.
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    An Analysis of Influential Factors on MRI Artifacts of Oral Non-precious Metal Prosthesis.
    CHEN Yi, LI Hui, WANG Li-yan, LIU Gang, FAN Xin-hao, HUI Xin-yu .
    2016, 32(10): 1024-1027.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.006
    Abstract ( 251 )   PDF (968KB) ( 219 )  
    Objective: To investigate influential factors on MRI artifacts of oral non-precious metal prosthesis. Methods: Two kinds of non-precious metal dental materials (Ni-Cr alloy and Co-Cr alloy) were molded into standard post-core-crown models as experimental group. Acrylic resin post-core-crown with the same size and shape was used as control group. The models were fixed in a water phantom. The Ni-Cr alloy, Co-Cr alloy and acrylic resin post-core-crown models were scanned by 1.5T MR scanner with the head coil. Scanning strategy was as follows: 1) Ni-Cr alloy, Co-Cr alloy and resin posterior teeth were selected, and axial T1WI, T2WI, T2*WI, FLAIR, DWI sequences were scanned respectively. 2) Ni-Cr alloy and Co-Cr alloy posterior teeth were selected, and axial, sagittal, and coronal T1WI, T2WI sequences were scanned respectively. 3) Ni-Cr alloy anterior tooth and posterior teeth were selected, and axial, sagittal, and coronal T2WI sequences were scanned respectively. The section with the greatest artifact was determined and the area was measured. Statistical testing was performed. Results: The sizes of the artifacts in descending order were as follows: Ni-Cr alloy, Co-Cr alloy and acrylic resin post-core-crown (P<0.01). The sizes of the artifacts were different at different sequences, and in descending order were DWI, T2*WI, T2WI, T1WI and FLAIR (P<0.01). The sizes of the artifacts were different at different sections (P<0.01). The artifacts of the posterior teeth were greater than those of the anterior teeth (P<0.01).Conclusion: It is feasible to choose Co-Cr alloy in non-precious metal for its better biocompatibility and less artifacts.
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    Effect of hBMP-2 Modified beta TCP/Collagen I Composite on the Proliferation of MC3T3-E1 Cells.
    ZHAO Gang, ZHU Xu-jia, DING Yuan-sheng, MO Hong-bing, ZENG Juan, SONG Tian-xi.
    2016, 32(10): 1028-1032.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.007
    Abstract ( 254 )   PDF (1061KB) ( 173 )  
    Objective: To explore the effect of hBMP-2 modified beta TCP/collagen I composite on the proliferation of MC3T3-E1 cells. Methods: Nano beta TCP/collagen I solution composite materials were modified by plasmid DNA containing hBMP-2 as the target gene, then the MC3T3-E1 cell line and nano composite materials in vitro culture system were established. Cells were divided into stent group and plate group, scanning electron microscope (SEM) and optical microscopy were used to observe the cell morphology, while cell proliferation and cycle were detected by Alamar Blue and MuseTM Cell analyzer assays, respectively. Real-time fluorescence quantitative PCR were applied to measure cell proliferation genes Cdk2 and Cdk4. Results: Cell adhesion, proliferation and distribution of the stent group were higher than those of the plate group (P<0.05). Conclusion: Compared to the plasmid DNA containing hBMP-2 only, hBMP-2 modified beta TCP/collagen I composite was better at stimulating preosteoblast adhesion, proliferation and metabolism. It might be used as bone repair or tissue engineering materials.
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    Expression of P2X Receptors in the Brainstem Induced by Dental Pulp Inflammation.
    CHEN Xia, YUAN Tong-sui, YE Fang, SUN Yu, YANG Jian, GUO Jun, JIN You-hong.
    2016, 32(10): 1033-1037.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.008
    Abstract ( 292 )   PDF (1434KB) ( 322 )  
    Objective: To study the expression of P2X receptors in the trigeminal spinal subnucleus caudalis (Vc) and the ventral posteromedial nucleus (VPM) induced by dental pulp inflammation.Methods: Cavities were prepared on the left first upper molars via a 1/2 # round ball drill, and the cavities with exposed dental pulp were left open to the oral microflora for 1, 3, 7 and 28 days. The Vc and VPM were harvested at specific time intervals and underwent further immunofluorescent and immunohistochemical procedures to assess the expression patterns of P2X1-7.Results: Acute inflammation was induced by dental pulp exposure from 1d to 7d, and chronic inflammation around the apical area of the root was observed after 28d. The P2X1-6 receptors were expressed in neurons, whereas P2X7 was expressed in microglia. Varying increases in the expression of the P2X1-7 receptors were characterized during acute and chronic pulp inflammation. The expressions of P2X2, P2X4 and P2X7 in the ipsilateral Vc, and P2X1-5 and P2X7 in the bilateral VPM, especially on the contralateral side were increased during acute inflammation process.Conclusion: The present findings suggest that all of the P2X receptors except P2X6 are involved in different ways in the Vc and VPM after dental pulp injury.
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    Electronic Structure of Infiltrating Resin Bonded on Decalcified Enamel.
    PEI Xiu-jie, LIU Ya-li, BAI Yu-xing.
    2016, 32(10): 1038-1041.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.009
    Abstract ( 287 )   PDF (1037KB) ( 296 )  
    Objective: To observe the micro structure of the infiltrating resin bonded on the decalcified enamel. Methods: Twelve extracted human molars were collected and divided into 2 groups. The enamel of the teeth was healthy in one group and the enamel was decalcified in the other group. The decalcification model of the enamel was manually established, and then the infiltrating resin was applied on the surface of the decalcified enamel. The enamel before or after etched by hydrochloric acid gel and the adhesive interfaces of the resin and the enamel were observed using scanning electron microscope (SEM). Results: The depth of decalcification was only about 10 μm on the surface of the enamel of healthy teeth. The calcifying layer on the surface of decalcified enamel can be cleaned by the hydrochloric acid gel thoroughly, which facilitated the infiltrating resin penetrating into the decalcified enamel adequately. However, there were several intervals between the resin tags and the body of enamel. Conclusion: The infiltrating resin could penetrate into the micro-structure of decalcified enamel and form the reticular structure on the surface of the enamel which could seal the decalcified enamel.
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    Antibacterial Effects of Lactobacillus Salivarius W22a on the Periodontal Pathogens.
    XUE Long, WANG Li-he, NIE Hong-bing, ZHOU Hai-jing, GUO Man-li, KANG Yong-jie, YANG Lan.
    2016, 32(10): 1042-1046.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.010
    Abstract ( 313 )   PDF (1058KB) ( 284 )  
    Objective: To evaluate whether the oral administration of Lactobacillus salivarius w22a could alleviate the peri-implantitis pathogens in subgingival plaque, such as Porphyromonas gingivalis (Pg), Pevotella intermedia (Pi), and Fusobacteriurn nuclearum (Fn) in vitro.Methods: The antagonistic growth effects of Lactobacillus salivarius as well as their probiotic on periodontal pathogens, including Pg, Pi and Fn, were tested using drug resistance experiment, agglutination experiments, and antibacterial experiments.Results: The results revealed that Lactobacillus salivarius w22a could produce antibiotics such as organic acid, hydrogen peroxide and EPS. Strain w22a could resist lysozyme and antibiotics at certain concentration. In addition, auto-agglutination and agglutination with other pathogens could be observed. The fermentation of w22a inhibited the growth of pathogens to varied degrees.Conclusion: Lactobacillus salivarius w22a was a potential probiotic strain to inhibit the growth of Pg, Pi and Fn in vitro.
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    Effect of Combined Utilization of Lavender Scent and Music on Patients' Anxiety during Dental Implant Surgery.
    CAO Yong, HE Hao-yu, WANG Ya-ke.
    2016, 32(10): 1047-1050.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.011
    Abstract ( 320 )   PDF (968KB) ( 322 )  
    Objective: To evaluate the effect of lavender scent and music on patients' blood pressure, heart rate and pain during dental implant surgery. Methods: One hundred and sixty patients undergoing single tooth implantation were selected and divided randomly into four groups (40 in each group). In group A (control group), patients underwent surgery in routine condition. In group B (lavender group), patient underwent surgery in lavender scent condition. In group C (music group), patient underwent surgery in music condition. In group D (lavender + music group), patient underwent surgery in lavender and music condition. Patients' gender, age, dental fear value, blood pressure, and heart rate were recorded before surgery. Cardiogram monitor was applied to monitor patients' blood pressure and heart rate during surgery. The visual analogue scale (VAS)was assessed after surgery. Results: Blood pressure of group B, C, and D had no change before and during the surgery, while there was a rise in group A (P<0.05). Heart rate of group B and C had no change before and during the surgery, while there was a rise in group A and a reduction in group D(P<0.05). An evaluation of VAS did not show difference among group B, C, and D, while group A had higher VAS(P<0.05). Conclusion: Lavender scent and music each can effectively sustain implant patients' blood pressure and heart rate during surgery and alleviate their pain at the same time, and the combination of both could lower the heart rate.
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    Expression and Significance of Bmi-1 and P16 in Oral Carcinogenesis.
    LI Yong, WANG Chun-feng, ZHAO Guang-ye, LIU Yi-long, HUANG Yuan-qing, CAI Yang.
    2016, 32(10): 1051-1055.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.012
    Abstract ( 330 )   PDF (872KB) ( 227 )  
    Objective: To investigate the expression of Bmi-1 and P16 proteins in oral precancerous lesions and oral squamous cell carcinomas (OSCC), and elucidate their possible roles pathway in oral carcinogenesis.Methods: The tissues of 10 cases of normal oral epithelium, 31 cases of different-degree epithelium dysplasia and 61 cases of OSCC with different differentiation were collected and investigated for the expression of Bmi-1 and P16 proteins by using immunohistochemistry. The clinical and pathological significance of Bmi-1 over-expression in oral carcinogenesis was statistically analyzed by SPSS11.5.Results: The percentages of positive staining for Bmi-1 were 0 % in normal oral mucosa, 29% (9/31) in epithelial dysplasia and 62.3% (38/61) in OSCC, respectively. The percentages of positive staining for P16 were 100% (10/10) in normal oral mucosa, 77.4% (24/31) in epithelial dysplasia and 47.5% (29/61) in OSCC, respectively. The percentage of Bmi-1 over-expression with negative P16 staining in OSCC was significantly higher than that in OSCC with positive P16 staining (P<0.05), and there was a negative correlation between the expression of Bmi-1 and P16 in OSCC (r=-0.414, P<0.05). In addition, the over-expression of Bmi-1 and low-expression of P16 were positively correlated with TNM stage and lymph node metastasis in OSCC (P<0.05).Conclusion: Up-regulation of Bmi-1 was an early event in oral carcinogenesis, and might be caused by the down-regulation of P16 in OSCC, closely correlated with TNM stage and lymph node metastasis. Bmi-1 could be used as a marker for assessing the progression and prognosis of OSCC patients.
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    Clinical Evaluation of IPS E.max CAD Ceramic Onlay Restoration of Endodontically Treated Posterior Teeth.
    HUANG Chen-chen, PAN Li-na, ZHANG Wei, XU Qing-an, FAN Ming-wen.
    2016, 32(10): 1056-1059.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.013
    Abstract ( 524 )   PDF (833KB) ( 562 )  
    Objective: To evaluate the clinical effect of IPS e. max CAD ceramic onlay restoration of endodontically treated posterior teeth. Methods: Forty-six endodontically treated posterior teeth were restored with IPS e. max CAD ceramic onlay designed by CEREC SW4.2. After 12 months, the patients were recalled. The teeth with restoration were assessed by using the modified USPHS criteria including secondary caries, gingivitis, tooth fracture, marginal discoloration, marginal integrity criteria and restoration fracture/debond, etc. At the same time, the patient's satisfaction was evaluated. Results: Of all the 46 teeth, 40 were scored A in all aspects. One tooth was fractured. The total satisfactory rate of patients was 92%.Conclusion: Ceramic onlay made by CAD/CAM is an effective restoration for endodontically treated posterior teeth.
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    3-year Clinical Evaluation of IPS e.max Press Occlusal Veneer for Single Posterior Tooth.
    WEI Xu, YANG Yun, HAN Wei, ZHANG Kai, NIE Rong-rong, SUN Fang-fang.
    2016, 32(10): 1060-1063.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.014
    Abstract ( 347 )   PDF (885KB) ( 447 )  
    Objective: To observe and evaluate 3-year clinical performance of IPS e.max Press occlusal veneer for single posterior tooth. Methods: 35 posterior teeth of 28 patients (18 with severe tooth wear and 17 with occlusal defect after root canal treatment) were restored with IPS e.max Press occlusal veneer. The restorations were evaluated by Modified US Public Health Service criteria at baseline in month 1, 6, 12, 24 and 36. The chi-square test was used to analyze the survival rate. Results: The anatomical form, marginal adaption, soft tissue health, secondary caries and proximal contact points of the restorations were good during 36 months. 2 mandibular premolars’ occlusal veneers were lost at 24 months. But chi-square test showed no significant difference between different time points. The percentage of success rate with A score was above 90%. Conclusion: The occlusal veneer fabricated by IPS e.max Press for the restoration of posterior tooth with severe wear or occlusal defect after root canal treatment demonstrated satisfactory clinical performance during 36 months. Minimally invasive dentistry was a new method for the restoration of posterior tooth defect. Further study was still needed for its long-term outcome.
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    Expression and Significance of Pinx1 in Oral Squamous Cell Carcinoma.
    LV Shan-shan, WEI Xiu-feng, SUN Xin, ZHOU Yang, WEI Yu-xue, LIU Tong, GAO Xu.
    2016, 32(10): 1064-1066.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.015
    Abstract ( 259 )   PDF (881KB) ( 219 )  
    Objective: To explore the expression and significance of Pinx1 in oral squamous cell carcinoma (OSCC). Methods: The expression of Pinx1 in 60 cases of OSCC and 20 cases of normal oral mucosa (NOM) was detected by immunohistochemistry. Results: The high expression of Pinx1 in the NOM epithelium was detected, and the positive rate was 100%. By contrast, the expression and positive rate (65%) of Pinx1 was significantly decreased in OSCC (P<0.05). With the increase of malignant degree, PinX1 expression showed a decreased trend (P<0.05). In addition, PinX1 expression level was significantly lower in OSCC patients with lymph node metastasis than those without lymph node metastasis (P<0.05). The expression of Pinx1 was not correlated with the gender and age of OSCC patients.Conclusion: Pinx1 may be related to the occurrence, development and metastasis of OSCC.
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    Effect of Photodynamic Therapy on Patients with Type II Diabetes Mellitus and Chronic Periodontitis.
    HOU Jia, TAO Hong.
    2016, 32(10): 1067-1069.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.016
    Abstract ( 240 )   PDF (779KB) ( 247 )  
    Objective: To explore the therapeutic effect of photodynamic therapy (PDT) on patients with type II diabetes mellitus and chronic periodontitis. Methods: Forty-eight patients with chronic periodontitis were randomly divided into PDT group (n=24) and control group (n=24) with and without PDT after supragingival scaling, and scaling and root planning (SRP). Levels of fasting blood glucose (FGP) and glycosylated hemoglobin (HbAle), and periodontal status were examined as well as matrix metalloproteinase-8 (MMP-8) and interleukin-1 (IL-1).Results: The total effective rate of PDT group was 91.67%, which was significantly higher than the control group (P<0.05). Three months after treatment, the level of HbAle in PDT group was significantly lower than that of one week after supragingival scaling without PDT and the control group (P<0.05). PD, AL, BI, and PLI were significantly decreased in the two groups after 6 weeks and 3 months after treatment. Compared with the control group, the PDT group was significantly decreased (P<0.05). The level of MMP-8 and IL-1 were significantly decreased in two groups after treatment (P<0.05), while the PDT group decreased more significantly (P<0.05).Conclusion: PDT can effectively improve periodontitis patients with type II diabetes, and reduce the level of inflammation reaction.
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    Preliminary Study on Partial Odontectomy in Extraction of Impacted Mandibular Third Molar Close to Inferior Alveolar Nerve.
    DAI Yin-hua, DAI Qun, GANG Jian-lin.
    2016, 32(10): 1070-1073.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.017
    Abstract ( 343 )   PDF (846KB) ( 470 )  
    Objective: To preliminarily investigate postoperative complications, movement of impacted mandibular third molars (IMTMs) and related factors after the surgery of partial odontectomy to extract IMTMs close to inferior alveolar nerve canal (LANC).Methods: 44 IMTMs, which met the inclusive criteria, were included. They were all extracted by partial odontectomy. Occurrence of postoperative pain, dentine hypersensitivity at the 24th hour and the 7th day after partial odontectomy were recorded. At the 6th month, migration of the roots was measured. When the roots departed from the LANC, they were removed. At the 7th day after the removal, the sensory function of IAN was checked.Results: The incidence of postoperative pain was 31.8% at the 24th hour, showing a significant correlation (P<0.05) with the status of eruption and the depth of the impacted tooth. No pain was observed for all patients on the 7th day after surgery. The incidence of dentine hypersensitivity was 79.5% at the 24th hour postoperative, showing a significant correlation (P<0.05) with the status of eruption, the depth of the impacted tooth and the exposure of dental pulp. However the incidence decreased to 27.3% on the 7th day postoperative. All the roots departed from IANC, and the average moving distance was 2.5±0.6mm in the 6th month, which had a negative correlation (P<0.05) with the age. No case of IAN injury was noted following root removal.Conclusion: Partial odontectomy is a worthwhile approach to extract the IMTMs close to the IAN, as it minimizes or even eliminates the IAN injury risk and postoperative complications.
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    Application of Materialise’s Interactive Medical Image Control System (Mimics) in the Mandibular Tumor Resection and Defect Reconstruction.
    ZHANG Yong-fu, JULAITI Tuerxun, MAIMAITITUXUN Tuerdi, YAO Zhi-tao, ADILIJIANG Saimaiti, LIU Yang.
    2016, 32(10): 1074-1078.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.018
    Abstract ( 481 )   PDF (971KB) ( 382 )  
    Objective: To investigate the applicative value of the interactive medical image control system’s (MIMICS) in mandibular tumor resection and reconstruction of mandibular defect with fibula flap and provide reliable basis for precise preoperative designing plan and desirable postoperative reconstructive result. Methods: Between November2014 and December2015, ten patients with mandibular tumor were treated in our department. Their mandible, maxilla and the donor leg received spiral CT scans preoperatively. DICOM data generated from the scanning were imported into MIMICS to observe the safe resection margin, simulate tumor resection, restore the effected side, reconstruct with fibula flap and predict the outcome. According to the preoperative design, the tumor was resected completely, fibula flap was shaped, titanium plate was bent and fixed, and the fibula flap went to position during operation. Results: All operations were completed successfully according to the preoperative plan, and all fibula flaps survived after the operations. Postoperative follow-ups were done 1, 3, 6, 9 and 12 months after operation and panoramic radiograph and CT were taken. All fibula flaps were in good position. Mouth opening of the patients varied from 2 to 3 fingers. All the donor leg fibula wounds healed well, with no obvious complications. All patients were satisfied with the facial aesthetics and the donor leg function. Conclusion: Pre-surgery planning including presurgical evaluation and outcome prediction with the aid of MIMICS which makes use of preoperative CT data in the mandibular tumor resection and defect reconstruction increases the accuracy of the tumor resection, and improves continuity and symmetry of the mandible.
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    Retrusive Guidance Used in the Correction of Skeletal Class II Malocclusion with Mandibular Retrusion.
    WANG Ming-Feng, LI Fu-Jun, YE Lu-Ping, JIANG Hong-Tao, LIU Lin, SATO Sadao.
    2016, 32(10): 1079-1082.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.019
    Abstract ( 313 )   PDF (887KB) ( 354 )  
    Objective: To introduce and evaluate the method to correct skeletal class II malocclusion with mandible retrusion by using retrusive guidance. Methods: Sixteen patients with skeletal class II mandibular retrusion, aged from 16 to 30 were treated. Before treatment, SNA was normal, SNB≤75°, ANB≥5°. Molar relationship was class II. The treatment began with aligning and leveling the upper and lower dental arch, then upper arch was expanded when necessary. Multiloop edgewise arch wire (MEAW) was used to eliminate molar interference, then to extrude lower premolars and tip back upper posterior teeth, so premature contact could be obtained and premolar retrusive guidance was established to guide the mandible forward. Results: Molar relationship of class II was improved to class I. SNB increased by 1.580 on average. Lower anterior teeth flared slightly but not significantly. Conclusion: To some extent, the retrusive guidance can be used to correct skeletal class II malocclusion with mandible retrusion.
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    Effect of Different Peroxides on Enamel Structure and Hardness.
    NAI Zheng-gang, SU Shi-bing, JIAO Zhi-xin, JIA Mei-e, WANG Xue-mei.
    2016, 32(10): 1083-1085.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.020
    Abstract ( 405 )   PDF (882KB) ( 1069 )  
    Objective: To determine the enamel surface structure and hardness of the extracted teeth after bleached with three kinds of peroxide bleaching agent: 30% hydrogen peroxide (HP), 22% carbamide peroxide (result peroxide, CP) and 3% boric acid (sodium perborate, SP) commonly used in clinics. Methods: Specimens of the extracted teeth were randomly divided into four groups (ABCD) which were treated with normal saline, 30% hydrogen peroxide, 22% had carbamide peroxide and 3% boric acid sodium respectively. Then the teeth were observed by scanning electron microscope (2000) x and evaluated with Vickers hardness measurement, followed by statistical analysis. Results: Scanning electron microscopy showed that the enamel surface of teeth treated with 30% hydrogen peroxide and 3% boric acid sodium presented scattered honeycomb erosion, suggesting different degrees of tooth demineralization and dissolution. While the enamel surface of teeth treated with 22% over oxidation urea was intact, showing no obvious tooth demineralization and dissolution. Hardness determination results showed that statistical differences existed between groups with pairwise comparison (P<0.05). The hardness comparison of teeth treated with different groups were control group > 22% carbamide peroxide group > 3% over sodium borate > 30% hydrogen peroxide. Conclusion: Among the three tooth whitening agents, 22% cardamide peroxide showed the minimal impact on tooth enamel structure and hardness.
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    Effects of Sonic Application on Bonding Fiber Posts to Root Canals.
    WANG Su, ZHAO Yi.
    2016, 32(10): 1086-1088.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.021
    Abstract ( 243 )   PDF (791KB) ( 232 )  
    Objective: To evaluate the effect of the application mode of etch-and-rinse adhesives on the push-out bond strength (PBS) and nanoleakage (NL) of fiber posts in the root canal. Methods: The roots of human premolars were endodontically prepared and divided into 2 groups according to the application mode (manual or sonic). The posts were cemented and the PBS tested at 0.5 mm/min. The NL was evaluated by scanning electron microscopy after the immersion of specimens in 50% silver nitrate. Root third was also considered in the statistical evaluation. Data were analyzed by t and chi-square tests. Results: Under sonic application, the PBS increased, whereas NL decreased significantly in the middle and apical thirds (P<0.05). Conclusion: The application of simplified adhesives by sonic mode in the root canal is a feasible tool to increase the fiber post bond to root canals.
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    Influence of Reverse Trendelenburg Position on the Blood Loss in Orthognathic Surgery.
    GAO Bo, YI Biao, LI Zi-li, LIANG Cheng, WANG Xiao-xia, LI Yang.
    2016, 32(10): 1089-1091.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.022
    Abstract ( 292 )   PDF (777KB) ( 208 )  
    Objective: To compare the blood loss under the reverse Trendelenburg 10° position and the horizontal position in patients with bimaxillary orthognathic surgeries. Methods: Sixty-three patients were enrolled in the prospective, randomized clinical study. Thirty-two subjects accepted the surgeries under the reverse Trendelenburg 10° position and 31 subjects under the horizontal position. The intraoperative blood loss and the bleeding per minute during Le Fort I osteotomy, bilateral sagittal ramus osteotomy and horizontal genioplasty were estimated.Results: The total blood loss of the surgeries under the reverse Trendelenburg 10° position (147.1±62.6) mL was significantly lower than that of the surgeries under the horizontal position (243.9±86.8) mL (P<0.001). The bleeding per minute of the surgeries under the reverse Trendelenburg 10° position (0.78±0.25) mL/min was also significantly lower than that of the surgeries under the horizontal position (1.20±0.39) mL/min (P<0.001). The surgeons had significant influence on the total blood loss (P<0.001) but no significant influence on the bleeding per minute (P=0.78). Conclusion: Compared to the horizontal position, the reverse Trendelenburg position 100 can significantly reduce the blood loss in bimaxillary orthognathic surgery. The shorter operative time was, the smaller amount of the total blood loss was.
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    A Retrospective Analysis of Platform-switching Implants with Abutment Fracture.
    CHEN Yu-huan, ZHANG Zhi-yong, ZHANG Xiao, MENG Tian, CHEN Quan, GAO Wei, LIU Wen-shu, ZHOU Tuan-feng, ZHANG Feng.
    2016, 32(10): 1092-1095.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.023
    Abstract ( 282 )   PDF (864KB) ( 245 )  
    Objective: To collect the cases of platform-switching implants with abutment fracture and analyze the reasons for clinical treatment. Methods: We collect platform-switching implants with abutment fracture from 2007 to 2014 in the Outpatient Department of Peking University School of Stomatology. Inclusion criteria: using Ankylos implants; patients with complete data; imaging and clinical examination confirmed abutment fracture. Results: Abutment fracture occurred in 16 patients, 17 implants and 18 abutments, including 9 males and 7 females. The average age was 47.69±9.56 years old. The average functional loading time was 3.89±1.68 years. No bone resorption was observed. Conclusion: Abutment fracture was likely to occur in the first molar and canine regions where the mastication force is great. Platform-switching implants showed the stability of the marginal bone. It should be taken serious consideration to choose platform-switching implant when the space of the tooth is large in the first molar region.
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    Effect of Customized Transparent Silicon Rubber Template on the Microleakage of Anterior Composite Resin Inlay Restoration.
    ZHENG Xiu-li, LIN Yuan-yuan, GUO Xin, WANG Liu-li, FENG Jian-qiao.
    2016, 32(10): 1096-1099.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.024
    Abstract ( 608 )   PDF (827KB) ( 362 )  
    Objective: To investigate the influence of customized transparent silicon rubber template on the microleakage of the composite resin inlays in conservative restoration of the anterior teeth. Methods: Thirty healthy extracted anterior teeth were selected and were randomly divided into three groups (group A, group B, and group C), and Class Ⅳ cavity was prepared on each tooth. Group A were restored with composite resin inlays directed by customized transparent silicon rubber template, group B were directed by traditional silicone impression template, and group C was restored directly by composite resin and all-etching bonding system. Composite resin inlays in group A were bonded to the teeth under the direction of customized transparent silicon rubber template. After thermal cycling and dying, all the specimens were examined by stereomicroscope. Results: The microleakage existed in all three groups. The microleakage values of group A and group B were less than that of group C (P<0.05). The microleakage value of group A was slightly lower than that of group B but without significant difference. Conclusion: The customized transparent silicon rubber template could reduce microleakage value between restoration and tooth.
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    Peripheral Complex Odontomas Erupting in the Gingiva Symmetrically on both Sides of the Bilateral Mandibular Second Molar and Literature Review.
    ZHU Yuan-ping, WANG Hua, HONG Li.
    2016, 32(10): 1100-1102.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.025
    Abstract ( 239 )   PDF (853KB) ( 239 )  
    Objective: Analyzed clinical and rare features of one patient with rare mandibular bilateral second molar distal gingival tissue symmetry eruption of Complex odontoma, and combined with literature to explore the pathogenesis of the disease. Methods: Analyzed clinical data of one patient who was accurate diagnosed with rare mandibular bilateral second molar distal gingival tissue symmetry eruption of Complex odontoma in our hospital and reviewed literature. Results: The patient had no history of trauma ,special infection and genetic disease , The patient with rare mandibular bilateral second molar distal gingival tissue symmetry eruption of Complex odontoma without teeth shape, unsmooth surface, with the presention of solid calcified mass, and matching mandibular bilateral distal to the second molar occlusal surface consistent. Conclusion: We found Adolescent dental odontoma by X-ray examination, non trauma, infection, genetic history of the individual may also occur in peripheral of mixed odontoma, the sprouting output may be by means of molar eruption, symmetry which is relatively rare may be related with gene expression and regulation of the abnormalities in the tooth germ early development.
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    Research Progress of Tooth Movement Predictability by Clear Aligner Treatment.
    ZHENG Wei-long, YUAN Gong-jie.
    2016, 32(10): 1103-1105.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.026
    Abstract ( 292 )   PDF (787KB) ( 541 )  
    In recent years, Clear Aligner Treatment(CAT)has been widely used in the clinic with the increasing aesthetic requirements of orthodontic patients. As a good adult treatment method, it is received extensive attention. Compared with the fixed orthodontic appliance, CAT is much more comfortable and the patient’s oral hygiene is easy to clean. This review is to expound the ability of the CAT accuracy control permanent dentition movement in all directions and provide theoretical guidance for efficacy prediction of tooth movement. The patients selected in the literature had no periodontal disease and alveolar bone absorption.
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    Status of Research Methods on the Stability of Micro-implants as Orthodontic Anchorage.
    SHAO Wen-ting, WANG Xue-jing.
    2016, 32(10): 1106-1109.  DOI: 10.13701/j.cnki.kqyxyj.2016.10.027
    Abstract ( 299 )   PDF (804KB) ( 283 )  
    In recent years, micro-implants are widely used in the clinical treatment of malocclusion patients because of their outstanding advantages. In order to make micro-implants play an effective role as anchorage, more and more scholars begin to pay close attention to research of stability of orthodontic micro-implants. Therefore, the purpose of this review is to summarize research methods about the stability of micro-implants from the histology, biomechanics and clinical evaluation.
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