Table of Content

10 March 2019, Volume 24 Issue 1

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The study on properties of guided bone regeneration of new type chitosan-based thermosensitive hydrogel membranes in vivo

LIANG Jie, ZHOU Ti, CUI Jun, et al

2019, 24(1):  1-4.  DOI: 10.12337/zgkqzzxzz.2019.03.001

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Objective： To observe chitosan/β-glycerophosphate salt(CS/β-GP) thermosensitive hydrogel mem-branes loaded enamel matrix proteins and detect the guided bone regeneration properties. Methods： CS/β-GP membranes were synthesized in vitro and loaded with EMPs. 10 male and healthy Wistar rats wererandomly divided into two groups(A and B). Critical size defect(CSD) in a diameter of 5mm was created onboth sides of the skull of the rats. The experimental side on the left was covered by CS/β-GP(1.0g) com-posite membrane loaded EMPs on the left and the control side was covered by CS/β-GP (1.0g) membraneon the right. The bone reparation of the groups on both sides was compared by observation, density mea-surement of newly formed bone and hematoxylin-eosin staining. Results： The percentage of bilateralbone density measured at 1 month and 2 months had statistical significance(P< 0.05). HE staining showedthat there were a few new bone formation on both sides at 1 month after operation. At 2 months after opera-tion, the new bone formation in the experimental side increased and became more compact and mature.Conclusion： This kind of CS/β-GP composite membrane has the characteristics of guided bone regener-ation, and can significantly accelerate bone healing after loading bioactive factors.

Age estimation in Sichuan Han female adults based on tooth volume analysis using cone-beam computed tomography

WANG Liang, ZHAN Mengjun, ZHAO Jialong, et al

2019, 24(1):  5-9.  DOI: 10.12337/zgkqzzxzz.2019.03.002

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Objective： Cone-beam computed tomography was used to analyze the tooth volume of different adults in order to estimate the age of females of Han nationality in Sichuan, and to explore the application value of tooth volume change in age estimation. Methods： CBCT images of 149 Han females aged 20 to 60 in Sichuan were collected. The pulp cavity volume (X1) and dentin volume(X2) of left maxillary central incisors were measured by Mimics 17.0 software, and the total tooth volume(X3) was calculated as the mea- surement index. Pearson correlation analysis was used to analyze the correlation between each measure- ment index and chronological age. Sixteen samples were randomly selected from the total sample as vali- dation samples, and the remaining 133 samples were used to develop regression equation for female adult age estimation. Results： Pearson correlation analysis showed that only pulp cavity volume(X1) was nega- tively correlated with chronological age(r=-0.666, P<0.001). Dentin volume(X2) and total tooth volume (X3) were not significantly correlated with chronological age(P>0.05). The results of model validation showed that the mean absolute error(MAE) of regression model based on pulp cavity volume(X1) was 7.723 year. Conclusion： CBCT can be used to observe the pulp cavity volume changes of left maxillary central incisors, which can be used to estimate the age of females adult of Han nationality in Sichuan, and provide a new method for the age estimation of adults in forensic practice in China.

Study of the cytotoxicity for 3D printed titanium alloy dental implants

WANG Hua, WANG Yao, ZHANG Biao

2019, 24(1):  10-13.  DOI: 10.12337/zgkqzzxzz.2019.03.003

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Objective： MTT colorimetric assay was used to detect the cytotoxicity of titanium alloy dental im- plant cast by 3D printing technology, and to evaluate the feasibility of the new casting process, so as to provide theoretical basis for further clinical application. Methods： We used professional software design to build the computer model, selected two different titanium alloys Ti-6Al-4V and Ti-6Al-7Nb as the casting raw materials, and cast three kinds of experimental standard plates of the same specification by 3D printing technology. The experiment was mainly divided into three groups, namely Ti-6Al-4V group, Ti-6Al-7Nb group and blank control group. By MTT colorimetric assay, we tested the effects of these three standard components on the proliferation rate of osteoblast MG63 to complete the evaluation of 3D printing technology. Results： Under the inverted phase contrast microscope, we observed that the growth status of cells in the three groups were all good, and there was no significant difference in cell morphology between the experimental group and the blank control group. MTT colorimetric results showed that the cy- totoxicity level of the two groups of titanium sheets was 0. Meanwhile, the proliferation rate of Ti-6Al- 7Nb titanium alloy sheets was slightly higher than that of Ti-6Al-4V titanium alloy sheet extraction solu- tion group. Conclusion： The cytotoxicity level of titanium alloy implants cast by 3D printing technology meets the requirements of clinical application of oral implant materials, and the cytotoxicity level of Ti- 6Al-7Nb is slightly lower than that of Ti-6Al-4V

Clinical study of the effect of implants with different implanting depth on marginal bone level

HUANG Jiangqin, WANG Yi, CEN Wen, et al

2019, 24(1):  14-18.  DOI: 10.12337/zgkqzzxzz.2019.03.004

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Objective： To evaluate the influence of implants with different implanting depth on the marginal bone level and discuss its clinical significant. Methods： 57 patients with 146 Bicon implants in the poste- rior region were included. According to implanting depth, there were 4 groups including group A of 1 mm less below the bone level, group B of between 1mm to 2 mm below the bone level, group C of between 2 mm to 3 mm below the bone level, group D of more than 3 mm below the bone level. The marginal bone level were evaluated by means of X-ray and SPSS 17.0 software package was used for statistical analysis. Results： After 5-years functional load, there was no significant difference in crestal bone loss among four groups(P>0.05), while there was a statistical difference among four groups(P<0.05) in the relationship be- tween the marginal bone level and implant neck platform. Conclusion： There was no significant effect of Bicon implant with different implanting depth on the marginal bone resorption,but implants implanted be- low the bone level might have more chance to keep the marginal bone stabilized at or above the implant platform.

Clinical observation of Er: YAG laser in combination with minocycline hydrochloride ointment to treat peri-implantitis

SHEN Xiaoyun, LIU Fengling, LI Wanjia

2019, 24(1):  19-21.  DOI: 10.12337/zgkqzzxzz.2019.03.005

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Objective： To observe the clinical effect of using Er: YAG laser in combination with minocycline hy- drochloride ointment to treat peri-implantitis. Methods： A total of 52 single implants from 52 patients were randomized into study group(Er: YAG laser and minocycline hydrochloride ointment treatment group) and control group(manual scraping treatment group). The efficacy endpoints of plaque, bleeding and probing depth are measured respectively in pre-treatment, week 1, month 1 and month 3 after treat- ment and then analyzed statistically. Results： There is no significant difference of periodontal clinical in- dicators before treatment between the study group and the control group(P>0.05), and all the clinical effi- cacy endpoints after treatment in two groups improved (P<0.05), at the same time the effect of study group is better significantly(P<0.05). Conclusion： The Er: YAG laser in combination with minocycline hydrochloride ointment have clinical effect significantly on peri-implantitis.

Correlation analysis of CRP, UDPd/Scr and other inflammatory markers in patients with dental implant restoration

WU Jianbo, YIN Li, GENG Fayun, et al

2019, 24(1):  22-24.  DOI: 10.12337/zgkqzzxzz.2019.03.006

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Objective： To analyze the correlation between C-reactive protein(CRP), urinary deoxypyridine (UD- Pd)/creatinine content (Scr) and inflammatory indicators in patients with oral implantation. Methods： 60 patients who received oral implantation in our hospital were selected as the observation group, and 60 healthy adults were selected as the control group. Serum C reactive protein(CRP), urinary deoxypyridine (UDPd)/creatinine(Sce), interleukin-1 (IL-1), interleukin 6 (IL-6) and tumor necrosis factor were com- pared between the two groups. Results： Serum CRP, IL-1, IL-6, TNF-levels and UDPd/ Scr in the obser- vation group were significantly higher than those in the control group 1 week and 1 month after surgery(P< 0.05), Pearson correlation analysis showed that CRP level in the observation group was positively correlat- ed with UDPd/Scr ratio 1 month after surgery(r=0.301, P=0.004). According to the X-ray examination re- sults, the patients were divided into the poorly integrated group(n=8) and the well-integrated group(n=52). The CRP, UDPd/ Scr ratio and IL-1, IL-6 and TNF-levels in the well-integrated group were significantly lower than those in the poorly integrated group(P<0.05). Conclusion： In the process of oral repair, serum CRP and urine UDPd/Scr ratio will be significantly increased and there is a positive correlation between the two. CRP, UDPd/Scr and other inflammatory indicators are correlated with the prognosis of patients with oral implantation and restoration.

A comparative study of restoration of residual crown root canal after treatment and implant restoration after extraction and its effect on VAS in patients

HUANG Jiechun

2019, 24(1):  25-28.  DOI: 10.12337/zgkqzzxzz.2019.03.007

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Objective： To compare the clinical effect of root canal repair after root canal therapy and implant re- pair after extubation, and the difference of VAS in patients with residual crown. Methods： From January 2016 to January 2018, 60 patients with residual crown were divided into observation group and control group. The observation group was treated with residual crown root canal and the control group was treated with tooth residual crown extraction. The visual analogue scale and visual analogue score(VAS) were com- pared between the two groups. Results： Three months after treatment, the clinical effects of the observa- tion group were better than those of the control group in four aspects: root stability, loosening of teeth, fixa- tion effect of prosthesis and masticatory function (P<0.05). The satisfaction rate of the patients repaired af- ter root canal therapy was 83.3%, and that of the patients with implant repair after extraction was 66.7%. The difference was statistically significant(P<0.05). VAS of the two groups showed that the pain degree was significantly reduced with the prolongation of the distance treatment time, but the pain degree of the observation group was lighter, the pain relief was faster, and the comfort degree of the patients was higher. Conclusion： The former has less pain and better effect than that after extraction, so it is worth choosing first.

Analysis of clinical effects of different implantation methods of micro implanted anchorage screws on orthodontic treatment

WU Zelin

2019, 24(1):  29-32.  DOI: 10.12337/zgkqzzxzz.2019.03.008

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Objective： To investigate the clinical effect of different implantation methods on orthodontic im- plants with micro implant anchorage screws. Methods： A total of 70 patients who were treated with orth- odontic treatment from April 2015 to January 2017 were selected as subjects. All patients were treated with mini-implantation anchorage. According to the implantation method, they were divided into control group and observation group, each with 35 cases. In the control group, the microscrew implants were im- planted at a vertical angle of 90 degrees. The observation group was treated with a microscrew implant an- chorage method. The effect of the implants was assessed 12 months after treatment. The two groups of pa- tients were recorded and statistically evaluated for the lower-middle incisor lip inclination angle, uppermiddle incisor lip inclination, and upper and lower mid-tooth incisional teeth angles. The occlusal force was measured before and after the patient's treatment of occlusal force, the chewing efficiency was evalu- ated using a weighing method. Evaluation, records and statistics of implant loosening, periodontal edema, discomfort, and incidence of gingivitis after treatment were compared between the two groups. Clinical ef- ficacy was compared between the two groups. Results： The 12-month curative effect of micro-screw im- plant anchorage in the observation group was 94.29%, which was higher than 68.57% in the control group (P<0.05). The inclination of tooth lip was smaller than that of the control group(P<0.05). In the observa- tion group, the angles of the upper and lower mid-incision teeth in the 12 months after treatment were all greater than those in the control group (P<0.05), the chewing function was not statistically significant be- fore treatment in the two groups(P>0.05), observing force and chewing efficiency were higher in the obser- vation group than in the control group at 12 months after treatment (P<0.05), implant group loosening, periodontal edema, discomfort, and incidence of gingivitis were observed in the observation group after treatment. Lower than the control group(P<0.05). Conclusion： The use of microscrew implant anchorage in orthodontic treatment can improve the clinical curative effect, improve the inclination of the lip and the chewing function, and the complication rate is low. It is worthy of popularization and application.

Digital guided dental implant restoration in anterior aesthetic area: a case report

CHEN Lin, CHEN Quanlin, WANG Binchen, et al

2019, 24(1):  33-36.  DOI: 10.12337/zgkqzzxzz.2019.03.009

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Objective： To report the diagnosis and treatment of a case of consecutive edentulous in anterior max- illary, and summarize the experience of integrated digital implant restoration. Methods： Clinical case was a 28 years old male patient whose 11, 12, 13, 21, 22 teeth were extracted due to trauma. A single GBR was used to restore the quantity of the soft and hard tissue. The intraoral data were obtained by the intra- oral optical scanning and the implant surgery was guided by static template. Results： 4 implants were im- planted, and the implant location was ideal. Imaging examination showed that the implant had good osseo- integration and the level of the surrounding bone was relatively stable, and showed good clinical esthetic outcome. Conclusion： Correct preoperative diagnosis, sufficient preoperative preparation and three-di- mensional digital simulation can enhance the precision of implant surgery, and make the final outcome take both biomechanical and aesthetic effects into consideration.

Clinical reports of failed dental implant replantation

SONG Guangbao, CHEN Qiyue, ZHANG Yang, et al

2019, 24(1):  37-40.  DOI: 10.12337/zgkqzzxzz.2019.03.010

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Objective： To observe the clinical effects of failed implant re-implantation, and to supplement the current treatment methods for failed implants. Methods： A retrospective analysis of 9 cases of patients im- planted in the Stomatology Hospital of Southern Medical University from February 2008 to June 2014, 8 cases of Straumann Standard 4.1×10mm implants, 1 case of Osstem SSII 4.1×11.5mm implants. The im- plant was implanted and restored for more than 1 year. The implant was obviously loose and painful when chewing, but the implant was not exposed, the soft tissue was not obviously red and swollen, and there was no obvious pyorrhea of the implant. X-rays shown Implant low density, but no significant horizontal and vertical bone defect image. Perform a failed implant replantation procedure under local anesthesia, the failed implants were washed with saline and the carbon fiber head scraper was used to clean the infected bone and fibrous tissue remaining on the implant surface. The bone defect was partially filled with Tianbo bone powder or Bio-Oss bone powder. Results： Nine of the loose dental implants were repaired for more than 1 year. The shortest use time was 4.5 years after implant restoration, the longest was 9 years, and the average service life was 6.5 years. 8 of the 9 replanted implants were repaired after 3 to 6 months, and on- ly 1 did not have osseointegration. New implants were implanted after removal, and repairs were complet- ed 3 months later. All torque values reached 35 Ncm. X-ray photos examined no low-density images around the implant. Conclusion： Replantation of failed dental implants can also achieve osseointegration and function. Some failed implants should not be simply discarded, and can be re-successed through reimplantation. Enriching the existing knowledge of the failure of dental implant treatment.