Evaluation the loosening of abutment screws in fluid contamination: an in vitro study.

Screw loosening is one of the most common clinical problems of dental implants. Research on the influencing factors of screw loosening is very important to prevent screw loosening. The purpose of this in vitro study was to evaluate the influence of liquid contamination on the screw loosening. According to the contamination condition, forty-five abutment screws were divided into three groups (n = 15): no contamination, artificial saliva contamination, and mouthwash contamination. The preload and friction coefficient of the abutment screws were recorded. Then, the reverse torque values (RTVs) and settlement were measured after 3.0 × 105 and 6.0 × 105 cycles. The surface wear of the screws was analyzed. Finally, the stress distribution of the abutment screws was calculated by finite element analysis (FEA). The results showed that fluid contamination reduced the friction coefficient, increased the preload, decrease the settlement, improved resistance to screw loosening, and reduced wear on the thread surface. Appropriate antimicrobial lubrication may improve the anti-loosening performance of abutment screws and prevent excessive wear on the threaded surface.

Factors associated with brain white matter damage in type 2 diabetes mellitus: a tract-based spatial statistics study.

BACKGROUND: The pathogenesis and related factors of central nervous system abnormality in patients with type 2 diabetes mellitus (T2DM) have always been the focus of clinical research. PURPOSE: To compare and analyze the area of white matter (WM) damage in patients with T2DM based on their level of hemoglobin A1C (HBA1c) and discuss any related factors. MATERIAL AND METHODS: Based on their levels of HBA1c, 87 patients with T2DM were divided into three groups (Group B, C, or D), of which 29 non-diabetic volunteers served as the control group (Group A). DTI data analysis was based on tract-based spatial statistics (TBSS). The obtained parameters were compared among each group and the relevant clinical factors were analyzed. RESULTS: For age, sex, mini-mental state examination (MMSE), and Montreal Cognitive Assessment (MoCA) scores, there were no statistically significant differences among groups. For fractional anisotropy (FA) and radial diffusivity (RD) of WM, there were statistically significant differences (P < 0.05, two-tailed, FWE corrected) in the local area of corpus callosum, corona radiate, superior longitudinal fasciculus, etc. Most of these were significantly correlated with body mass index (BMI), left systolic blood pressure (SBP_L), and ß2 microglobulin. CONCLUSION: Before the cognitive function was obviously impaired, abnormalities of FA and RD had been found in the corpus callosum, corona radiate, and upper fasciculus in patients with T2DM, which suggested that the damage mainly occurred in the myelin sheath of WM and may be related to systemic vascular damage.

[Comparison of short-term clinical effect and assessment of influencial factors around single-tooth in the aesthetic area: immediate implant placement versus delayed implant placement].

PURPOSE: To compare the short-term clinical effect and to assess the influencial factors of immediate implant placement and delayed implant placement around single-tooth implant in the aesthetic area. METHODS: A total of 114 patients requiring a single-tooth implant in the aesthetic area were reviewed at Center for Implant Dentistry of Stomatological Hospital of China Medical University. They were divided into immediate implant group and delayed implant group. The patients were followed up for 1 year after upper structure rehabilitation, and the pink esthetic score and the marginal bone absorption around the implants were measured. Statistical analysis was performed using SPSS 17.0 software package. RESULTS: After 1 year of upper structure rehabilitation, 114 implants were stable and the marginal bone absorption around the implants of the immediate implant group was (0.36±0.39) mm,significantly smaller than the delayed implant group [(0.79±0.67)mm, P<0.001]. The difference in PES score between the two groups were not statistically significant on the day of rehabilitation and 1 year after upper structure rehabilitation（P>0.05）. Significant improvement of PES on the day of rehabilitation and 1 year after upper structure rehabilitation and marginal bone absorption was found with flapless surgery. SLA and DAE surface treatment methods had no significant impact on PES and marginal bone absorption (P>0.05). Graft procedure had an unfavorable effect on PES value both on the day of rehabilitation and 1 year after upper structure rehabilitation. CONCLUSIONS: Under appropriate indications, immediate implant placement and immediate repair could reduce the time of missing teeth. The marginal bone absorption of immediate implant group is smaller than delayed implant group. Flapless surgery avoids damage to gingival tissue, reduces postoperative reaction and improves the aesthetic outcomes after repair.

[Application of 3D printing in the treatment of unilateral comminuted zygomatic bone fracture].

To explore the validity of 3D printing technique in the treatment of unilateral comminuted zygomatic bone fracture. METHODS: Twenty-one patients with unilateral comminuted zygomatic bone fracture were included in the present study, which were treated from hospital January 2014 to April 2017. All patients underwent CT scan and the data were imported in Mimics 10.01 software. The zygomatic bone of healthy side was mirrored to the fracture side to rebuild a "perfect" reduction model. Bone fixation plates were pre-modeled on the model printed by a 3D printing machine and used for bone reduction and fixation during operation. Three dimensional measurements were performed to evaluate the validity of 3D printing based on pre- and post-operative three dimensional CT model. SPSS25.0 software package was used to perform paired t test on the measured data. RESULTS: No significant difference were observed between postoperative CT model and preoperative "perfect" reduction model. All patients were satisfied with their facial appearance. CONCLUSIONS: 3D printing technique is helpful to improve the accuracy of reduction of unilateral comminuted zygomatic bone fracture via preoperative pre-modeling.

A new method of CT for the cardiac measurement: correlation of computed tomography measured cardiac parameters and pulmonary obstruction index to assess cardiac morphological changes in acute pulmonary embolism patients.

Acute pulmonary embolism (APE) is a serious disease which is life-threatening. Since it is crucial for APE patients to assess the changes of cardiac function safely and timely, the imaging research of cardiac morphology and function is becoming more and more important. The correlation of computed tomography (CT) measured cardiac parameters and pulmonary obstruction index (POI) was analyzed to discuss the morphological changes of the heart of APE patients in order to provide a new method to evaluate cardiac functions accurately and effectively. 118 APE patients confirmed with CT pulmonary angiography (CTPA) were divided into high-risk group (47 cases, POI ≥ 20) and low-risk group (71 cases, POI < 20) according to the Qanadli Score. The left to right diameter (RL) and the anteroposterior diameter (AP) of the cardiac chambers were compared among the high-risk group, the low-risk group, and the normal group (60 cases). The correlation between CT measured cardiac parameters and the POI was analyzed. Except for left ventricular AP and right atrial AP, there were statistically significant differences (P < 0.05) in the RL and AP of the each cardiac cavity, these parameters meant that right hearts were enlarged and the left hearts were decreased in size. The ratio of right/left heart diameter was statistically significant among the three groups, a < b < c (P < 0.05). Moreover, the POI of 118 APE patients was 14.29 ± 9.53, and there was significant linear correlation between CT measured cardiac parameters and the POI (P < 0.05), excluding the left ventricular AP and right atrial AP. The correlation coefficient reached 0.5 or more in terms of the right atrial LR, the right ventricular LR, the ratio of right/left atrial diameter and the ratio of right/left ventricular diameter. With the increasing value of POI, the right atrium and right ventricular of APE patients were enlarged, and the left atrium and left ventricular were decreased in size. These heart changes can be observed by using CTPA, even non-enhanced chest CT.

In Vivo Effect of Titanium Implants with Porous Zinc-Containing Coatings Prepared by Plasma Electrolytic Oxidation Method on Osseointegration in Rabbits.

PURPOSE: The aim of this study was to confirm the in vivo effect of surface-modified titanium (Ti) implants with zinc (Zn) prepared by a plasma electrolytic oxidation (PEO) method on the process of osseointegration. MATERIALS AND METHODS: Forty-five New Zealand white rabbits were used. Implants were divided into three groups due to different surface treatments (the PEO-Zn group, the PEO-calcium phosphorus [Ca/P] group, and the sandblasted [control] group) and were randomly inserted into rabbits' mandibles. The implant surface morphology and chemical state of the relevant elements were observed. The maximum push-out force, the bone-to-implant contact (BIC), and the mineral apposition ratio (MAR) were detected at 4, 8, and 12 weeks after implantation. RESULTS: A two-layer structure, with a dense inner layer and a porous outer layer, was found in the PEO samples. In the PEO-Zn group, CaHPO4·2H2O (dicalcium phosphate dihydrate) was the main calcium compound, and ZnO was identified as the predominant form of Zn. More bone deposition was found on the top of the PEO-Zn implant, which was also confirmed by scanning electron microscope (SEM) afterward, and the shear strength reached a maximum value of 1.57 ± 0.26 MPa at 12 weeks compared with the sandblasted group and the PEO-Ca/P group. The BIC values and the MARs of the PEO-Zn group were significantly higher than the control group, especially at the early weeks (P < .05), and first reached maximum values of 73.91% ± 9.01% and 4.89 ± 0.60 µm/d at 12 weeks, respectively. CONCLUSION: Implants with Zn coating by the PEO method could accelerate bone formation and bone remodeling, shorten the osseointegration period, and enhance bone-implant bonding force.

Laparoscopic resection of gastric duplication cysts in newborns: a report of five cases.

BACKGROUND: Gastric duplication cysts are rare congenital alimentary tract anomalies and most cases are recognized during childhood. There were few reports about gastric duplication cysts in newborns and even fewer reports about laparoscopic resection of gastric duplication cysts in newborns. CASE PRESENTATION: We report a series of five newborns with gastric duplication cysts which were successfully resected by laparoscopy between January 2010 and April 2015. Case 1, a male newborn was admitted because of severe salivation, choking cough and dyspnea for 30 min after birth. Case 2, a male, was suspected of duodenal ileus by antenatal examination. Case 3, a female was admitted because of vomiting for 5 days. Case 4,a female without significant symptoms simply visited us for the abdominal cyst detected by antenatal examination. Case 5, a male was admitted because of vomiting for 4 days. All patients were performed with a surgery after assistant examinations. Case 1 was died of respiratory failure and the other patients recovered uneventfully. CONCLUSION: Gastric duplication cysts in newborns are very rare. Laparoscopic surgery play an important role on the diagnosis and treatment. Our experience and practice indicate that laparoscopic resection of gastric duplication cysts in newborns is viable and there is also a need to increase sample size to prove its safety and effectiveness.

[Study of relationship between (Ca+Zn)/P of pure titanium surface coating and biological activity of osteoblasts].

PURPOSE: To study osteoblast (MC3T3-E1 cells) adhesion, proliferation and differentiation activity on the surface of pure titanium with different (Ca+Zn)/P ratios, and determine Ca, P, Zn contents offering best biological activity on pure titanium surface. METHODS: In the micro-arc oxidation electrolyte, Ca, P with a certain concentration, and 5 different concentrations of Zn (0, 0.01, 0.03,0.04, and 0.06 mol/L) were added, which made the mole ratio of Ca and P element close to the ratio of hydroxyapatite. (Ca+Zn)/P ratio of bioactive coating on 5 different pure titanium material surfaces were prepared, which named S0 and S1, S2, S3 and S4 group, respectively. The surface elements, existence form, (Ca+Zn)/P ratio and surface morphology were analyzed by XPS and SEM; MC3T3-E1 cells adhesion, proliferation and differentiation cultured on the material surface were analyzed by SEM, MTT method and ALP activity assay. RESULTS: The data was analyzed with SPSS13.0 software package. With the increase of Zn content in the electrolyte, (Ca+Zn)/P ratios were 2.94, 2.64 2.71, 2.87 and 2.72 in S0-S4 group, respectively. (Ca+Zn)/P ratio was maximal in S3 group and decreased in S4 group. MC3T3-E1 cell adhesion, proliferation and differentiation capacity on material surface of 5 groups changed in the following order: 3>S4>S2>S1>S0, with significant differences among 5 groups (P<0.05). CONCLUSIONS: Coating with different concentrations of Ca, P, Zn on pure titanium surface by micro-arc oxidation technique, the adhesion, proliferation and differentiation ability of osteoblast increase as (Ca+Zn)/P ratio increase, and cell biological activity is the best when the (Ca+Zn)/P ratio reached 2.87.

Correlation of computed tomography angiography parameters and shock index to assess the transportation risk in aortic dissection patients.

BACKGROUND: Aortic dissection (AD) is a serious, life-threatening disease. It is currently crucial for AD patients to be transferred to a specialised hospital in a safe and timely manner. For this reason, the search for clinical and imaging changes related to transportation risk is becoming increasingly important. PURPOSE: The transportation risks of AD patients were assessed by studying the correlation between computed tomography angiography (CTA) parameters and shock index. MATERIALS AND METHODS: Thirty-six cases of AD confirmed with 64-slice volumetric CT (VCT) (18 cases of Stanford type A and 18 cases of type B) were divided into a high-risk group (14 cases, six Stanford type A and eight type B) and a low-risk group (22 cases, 12 Stanford type A and 10 type B) according to the modified Early Warning Score. The shock index (ratio of heart rate to systolic blood pressure) and measured CTA parameters were compared between the high-risk group and the low-risk group, and the correlation between the measured CTA parameters and shock index was analysed. RESULTS: The shock index and ratio of false/true lumen were compared between Stanford type A and type B, and no statistically significant differences were found. The shock index and ratio of false/true lumen were compared between the high-risk group and low-risk group, revealing a statistically significant difference (p < 0.05). Moreover, a significant linear correlation was found between the ratio of false/true lumen and the shock index (r = 0.691; p = 0.001). CONCLUSION: The higher the shock index and the ratio of false/true lumen are, the greater the transportation risk for AD patients. The shock index and the ratio of false/true lumen proved to be essential clinical and radiological indices for assessing the transportation risk of AD patients.

[Study of relationship between different contents of zinc and antibacterial activity on calcium phosphate coating modified by plasma electrolytic oxidation method].

PURPOSE: Calcium phosphate activity coating containing different contents of zinc was deposited onto the surface of pure titanium modified by plasma electrolytic oxidation. The physical and chemical properties of different contents of zinc were compared among three groups, and the influence on antibacterial activity of P.gingivalis (Pg) and A.actinomycetemcomitans (Aa) was evaluated. METHODS: Pure titanium samples were treated in the electrolyte of plasma electrolytic oxidation with 0.08 mol/L calcium and 0.06 mol/L phosphorus, and 0.01, 0.03, 0.05 zinc was added to each group in order to deal with pure titanium plate. Titanium samples were divided into three groups: low, middle and high group according to zinc contents. The group without zinc was as control. The binding force of coating and titanium was tested by electric universal test machine. The topography of surfaces was observed under scanning electron microscope (SEM). The crystalline structure of surfaces was determined by XRD. The chemistry and elements of surfaces were determined by XPS. Pg and Aa were seeded onto samples surfaces, and the antibacterial properties of four kinds of materials were evaluated by using scanning electron microscopy and the paster method. Statistical analysis was performed using SPSS 13.0 software package. RESULTS: It was found that the aperture and roughness were increased with the increase of content of zinc. The crystallization of low zinc group was superior to high zinc group. The content of HA and Zn3P2 in low zinc group was more, but ZnO in high zinc group was more. Scanning electron microscope demonstrated that the number of Pg and Aa decreased on the surface with the increase of the content of zinc, while the bacteria of high zinc group underwent lysis and necrosis. By using the paster method, the number of Pg and Aa decreased on the surface with the increase of the content of zinc, and there was significant difference among the four groups. CONCLUSIONS: The change of zinc content will change the physical and chemical properties of the coating; at the same time, the antimicrobial property of calcium phosphate coating with high content zinc was the best.

[A clinical retrospective analysis of dental implants replaced in previously failed sites].

PURPOSE: To evaluate the clinical outcomes as well as related factors of dental implants replaced in previously failed sites. METHODS: A total of 12 patients (15 implants) who received replacement in previously failed sites during January 2005 to December 2011 were included. Outcomes of redo-implants were collected and clinical data was recorded and analyzed regarding risk factors related to redo-implants' survival using SPSS13.0 software package. RESULTS: The survival rate of redo-implants was 100% [(33.5±15.4) months]. The mean redo-implant diameter (4.5±0.6) mm was significantly larger than the previous one (4.1±0.7) mm (P<0.05). The mean survival time of implants placed for the first time was (12.9±15.9) months. Implant replacement occurred (6.8±4.4) months after original implant removal. No significant influence was observed on patient and implant-related factors as well as surgery and prosthesis-dependent factors. CONCLUSIONS: Reimplantation in previously failed site is considered as one of feasible prosthesis plans, and surgeons ought to get enough confidence to achieve satisfactory implant survival rates. Supported by Liaoning Provincial Natural Science Foundation (20092093), Liaoning Provincial Science and Technology Foundation (2012225090), and Shenyang Science and Technology Foundation (F11-264-1-25, F12-277-1-18).

[An assessment of different crown-to-implant ratio for implant teeth in the posterior region over 5 years].

PURPOSE: To evaluate the influence of crown-to-implant ratio (C/I ratio) on the results of restoration in the posterior region. METHODS: From January 2007 to January 2012,119 patients with 208 ITI implants in the posterior region were followed up for 6-66 months. Implant restorations were divided into three groups according to their respective clinical C/I ratios after noble porcelain-fused-to-mental crown restoration: C/I ≤1,11.5. Cumulative survival rate was calculated by life-table analysis. SPSS 13.0 software package was used for statistical analysis. RESULTS: The mean clinical C/I ratio of 208 implants was 1.07±0.24, with maximum C/I of 1.8 and C/I of 0.6, 9.6 percent; of 208 implants had biomechanical complications. Differences among three groups were not statistically significant in annual crestal bone loss and biomechanical complications. In addition,implant cumulative survival rate in C/I ratio>1 was 97.6 percent;,and 98.8 percent; in C/I≤ 1. CONCLUSIONS: Clinical C/I ratio does not significantly influence peri-implant crestal bone loss and biomechanical complications, implant restorations with C/I ratios>1 is successfully used in the posterior areas in this study.

Histomorphometrical and clinical study of connective tissue around titanium dental implants with porous surfaces in a canine model.

Connective tissue (CT) reactions and collagen fiber orientation were evaluated on titanium implants with porous surfaces made by a laser method. Three groups in which the diameters of pores were 10 ± 5 µm, 40 ± 5 µm, and 70 ± 5 µm were involved in this test, together with a machined group as control. A total of 24 implants were randomly placed in mandibles after 3 months of premolars and the first molar extraction in beagle dogs. All the implants were firmly anchored in the bone after 3-month insertion. Histological sections showed that the gingival tissue was attached tightly to implant surface and there was no significant difference in inflammatory cell invasion and probing depth among all groups (p > 0.05). Histomorphometric analysis demonstrated that no significant difference in total CT length was observed among four groups (p > 0.05), however, the gingival recession in the 40 ± 5 µm and 70 ± 5 µm porous groups was less than in the 10 ± 5 µm porous group and control group (p < 0.05). Collagen fibers at the inner zone of the CT around the 40 ± 5 µm and 70 ± 5 µm porous implants aligned mostly in an oblique orientation, while there was a mainly parallel fiber direction around the 10 ± 5 µm porous and control implants. It was noted that some fibroblasts and fibers in the 70 ± 5 µm porous group was inserted into the pores of implant surface, indicating that pores of a proper size on the implant surface could induce the insertion of CT and prevent gingival recession.

[The antibacterial properties of Ca and Zn-containing coatings prepared with micro-arc oxidation].

PURPOSE: To prepare Ca and Zn-containing coatings using micro-arc oxidation on pure titanium surface and to investigate the coatings effect on S.mutans adhesion and morphology. METHODS: Five groups including low Ca-containing (L-Ca), high Ca-containing (H-Ca), low Zn-containing (L-Zn), medium Zn-containing (M-Zn), high Zn-containing (H-Zn) were prepared with micro-arc oxidation on titanium surface and machined commercial pure titanium (CP) was used as control group. Antibacterial properties of S.mutans on samples surface were appraised by the paster method and the change of bacteria was observed by SEM. SPSS 13.0 software package was used for all statistical analysis. RESULTS: The results showed that L-Ca and H-Ca groups had no significant difference in antibacterial property(P>0.05);Zn-containing groups had distinct antibacterial effect(P<0.01) compared with CP group,and there was significant difference between L-Zn and H-Zn group (P<0.05). Meanwhile,Zn-containing groups could affect adhesion and morphology of S.mutans by SEM. CONCLUSIONS: Zn-containing coating prepared with micro-arc oxidation can effectively influence S.mutans adhesion and morphology, which shows better antibacterial effect with the increase of zinc content.

[Implant-supported overdenture after pectoralis major myocutaneous flap reconstruction of tongue/floor of the mouth cancer:a case report].

Patients with oral cancer, undergoing ablative surgery, were left with severe deformities and dysfunction. Although the defect can be repaired by flap transplantation, there were still difficulties to restore normal oral structure and function of the oral cavity. In these instances, rehabilitation of mastication and occlusion is of the utmost importance. This article described the procedure that implants were inserted and bar/clips retained overdenture was applied to a patient who underwent reconstruction with pectoralis major myocutaneous flap after cancer ablation surgery. The patient's oral structure and functions was recovered, and the quality of life was greatly improved.

[Effect of HA/TiO2 coating titanium surface on the growth of MG63].

PURPOSE: To evaluate the bioactivity of titanium surface treated by micro-arc oxidation (MAO) combined with ion beam assisted deposition (IBAD). METHODS: Titanium surfaces were treated by machined(S0), micro-arc oxidation(S1) and micro-arc oxidation combined with IBAD(S2), respectively. The topography and roughness of surfaces were determined by profilometer, and the bioactivity of the surface was evaluated by CLSM, MTT assay and ALP activity of cells. The data was analyzed by one-way ANOVA using SPSS11.0 software. RESULTS: The surfaces of S2 group were smoother than those of S1 group. On day 5, the OD value of S2 group was the highest among the three groups.10 days later, ALP activity on S1 and S2 groups were higher than that of S0 group. CONCLUSIONS: It is concluded that IBAD technique which provides HA coating on MAO surface could reinforce the bioactivity of micro-arc oxidation and could have a rapid osseointegration.

Comparison of biological characteristics of mesenchymal stem cells grown on two different titanium implant surfaces.

This study examined the biological characteristics of mesenchymal stem cells (MSCs) grown on sand-blasted, large-grit, acid-etched (SLA) surface and hydroxyapatite (HA) coating on the SLA (HA/SLA) surface of titanium dental implants. The HA/SLA surfaces of titanium dental implants were formed by the ion beam assisted deposition (IBAD) method. Rabbit bone marrow derived mesenchymal stem cells cultured in vitro were seeded onto the surface of SLA and HA/SLA; the growth states of MSCs on the two samples were observed by a scanning electron microscope; the proliferation index, alkaline phosphatase (ALP) activity, osteocalcin (OCN) content of MSCs and mRNA relative expression level of osteopontin (opn) were compared between two groups. MSCs were found to be easier to adhere to the HA/SLA surface compared to the SLA surface. At the same time, the ALP activity and the OCN content of MSCs grown on the HA/SLA surface were obviously higher, and the relative expression level of opn mRNA was 4.78 times higher than that on the SLA surface. The HA coating formed by the IBAD method on the SLA surface of titanium dental implants significantly improves proliferation and well-differentiated osteoblastic phenotype of MSCs, which indicates a promising method for the surface modification of titanium dental implants.

[Microcosmic analysis of TCP/HA coating with micro-pores on titanium by IBAD method.].

PURPOSE: In order to improve the biocompatibility of dental implants, the physical structure and the chemical composites of tricalcium phosphate/hydroxyapatite(TCP/HA) coating on titanium were studied. METHODS: Coatings of TCP/HA and hydroxyapatite (HA) on titanium were formed by ion beam assisted deposition (IBAD) method. The scanning electron microscope (SEM) and atomic force microscope (AFM) were used to study the morphology of the coating surfaces. The chemical components and structure of the modified surfaces were characterized using energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD). RESULTS: The results showed that there were many micro-pores in the TCP/HA coating by SEM and AFM. The chemical components analysis showed that the Ca/P ratio of TCP/HA coating was lower than that of HA coating. The XRD showed that the TCP/HA coating was composed of TCP and HA. CONCLUSION: The results indicated that the TCP/HA coating with micro-pores was formed on titanium by IBAD method successfully. With higher binding strength between TCP/HA and titanium, this coating will be a potential coating material for dental implant, especially for the biological seal at the cervical level of the implant.

[Human gingival epithelial cells cultured by a combined method of serum containing medium and serum free medium].

OBJECTIVE: To search for a simple and rapid cell culture method for human gingival epithelial cells with a high success rate. METHODS: Culture medium containing serum has been proved to have the ability of accelerating the early adhesion of human gingival tissue blocks, and the migration of gingival epithelial cells from the rim of the blocks. By means of this, we introduced the serum containing DMEM to the cell culture medium within the first 7-10 days, and changed with serum free cell culture medium to accelerate the mitosis, proliferation, and migration of the gingival epithelial cells, which had moved out from the tissue blocks. Using the combined method, cells were identified by the method of morphology, immunohistochemistry and analysis of the cell growth curve, as well as SEM. Compared study of the effects on the cell growth between combined method and serum containing DMEM or serum free EpiLife culture method was conducted. RESULTS: Cells were harvested within 17-22 days. Primary culture success rate was 90.6%. Cultured cells were slabstone-shaped. Immunohistochemistry analysis of keratin antibody showed a positive result. The cells had stronger ability of migration and proliferation in the serum free cell culture medium compared with that in the serum medium. CONCLUSION: This method can culture the gingival epithelium cells conveniently with accelerated speed.

[Effects of TCP/HA-coating titanium on the adhesion behavior of human gingival fibroblasts].

OBJECTIVE: To investigate effects of hydroxyapatite (HA) and porous tricalcium phosphate/hydroxyapatite (TCP/HA)-coating titanium on the adhesion behavior of human gingival fibroblasts (HGFs). METHODS: Coatings of HA and duplex phases TCP/HA on titanium (Ti) were formed by ion beam assisted deposition (IBAD) method. Attachment, spreading, extracellular matrix (ECM) production, and focal adhesion plaque formation of HGFs were investigated on commercially pure (CP) titanium, HA-coated CP titanium and porous TCP/HA-coated CP titanium. After incubation of HGFs on these substrates, the number of attached cell, the area of cell spreading, immunostained ECM including fibronectin (FN) and type I collage, and vinculin (presenting the formation of focal adhesion plaque) were quantified by morphometric analysis using immunofluorescence microscope. RESULTS: TCP/HA and HA coatings exhibited that the attached cell number and cell spreading area were greater than those of CP titanium (P < 0.05), and the formation of focal adhesion plaque was earlier than that of uncoated substrate (P < 0.05). The number of attached cell and the formation of type I collagen on TCP/HA were more than those on Ti and HA. After 24-hour incubation on TCP/HA surface, the number of attached cell was 198.1 +/- 27.7 and the fluorescent intensity of type I collagen was 154.10 +/- 31.56. While under the same condition, the corresponding numbers for the CP titanium were 125.1 +/- 29.9 and 132.63 +/- 35.26. The differences between the two groups were significant (P < 0.05). CONCLUSIONS: In this study, the porous TCP/HA coating significantly facilitated the adherence of human gingival fibroblasts to Ti surface and could improve the biocompatibility of titanium.