The effects of hyperglycemia on the biological behavior of human gingival fibroblasts on a titanium surface.

BACKGROUND: It is well known that diabetes mellitus is one of the high-risk factors for periodontitis and also for the failure of implant restorations. Usually, the success of an implant restoration depends on both the good osseointegration and the stable soft tissue interface on the implant neck. A good gingival interface of the implant neck is the barrier that enables implant to resist oral microorganisms and the site of initiation of peri-implantitis. This study sought to investigate the effects of hyperglycemia on the attachment and proliferation of human gingival fibroblasts (HGFs) on pure titanium surfaces. METHODS: HGFs were cultured in cell culture mediums with different glucose concentrations (i.e., 5.5, 8. 8, 10, and 15 mmol/L) for 7 d and seeded on pure titanium surfaces. The cells that were seeded on the titanium surfaces had been cultured in cell culture mediums with different glucose concentrations for 3 and 7 d. The attached HGFs on the titanium surfaces were counted for all groups using a blood cell counting plate, and the results were statistically analyzed. The morphologies of the attached HGFs on the titanium surfaces were observed for all the groups using a scanning electronic microscope. RESULTS: As the glucose concentrations increased, the number of attached HGFs on the titanium surfaces decreased. The numbers of attached cells in Groups A and B 7 d after being seeded on the titanium surfaces were more than those 3 d after being seeded (P<0.05). The numbers of attached cells in Groups C and D 3 d after being seeded on the titanium were more than those 7 d after being seeded (P<0.05). The scanning electronic microscope showed that the attached cells in Groups A and B proliferated well, and most cells grew one on top of another. Conversely, the attached cells in Groups C and D proliferated sparsely and the cell morphologies were not good. CONCLUSIONS: The attachment and proliferation of HGFs on pure titanium surfaces were inhibited by increases in glucose concentrations, and the inhibition was further enhanced by the passage of time.

[Morphological change analysis based on cone beam CT of the upper airway for obstructive sleep apnea syndrome patients treated with oral appliance in skeletal class ⠡ malocclusion with different vertical patterns].

OBJECTIVE: To analyze the morphological changes in the upper airway of obstructive sleep apnea syndrome (OSAS) patients treated with oral appliance in skeletal class Ⅱ malocclusion with different vertical features by using cone beam CT (CBCT). METHODS: Thirty-six patients diagnosed with OSAS by polysomnography and daytime sleepiness scale and skeletal class Ⅱ malocclusion were treated with oral appliance for 4 months. The changes based on CBCT in the morphology of glossopharyngeal and palatopharyngeal before and after treatment in OSAS patients with different vertical features were compared. RESULTS: After treatment with oral appliance, the glossopharyngeal and palatopharyngeal morphologies of patients with mild OSAS showed significant changes. After treatment with oral appliance, the glossopharyngeal morphology of all patients showed significant changes (P<0.05). The palatopharyngeal morphology of patients in the lower and average groups also exhibited significant changes (P<0.05). Sagittal changes in the glossopharyngeal measurements of high-angle patients demonstrated significant difference, whereas the other measured values showed no significant difference. CONCLUSIONS: The morphological changes in the upper airway were significant in OSAS patients with lower and average vertical patterns when treated with oral appliance, but the changes in high vertical patterns were not significant.

[Effect of diode laser in the treatment of 78 patients with sinus chronic apical abscess].

PURPOSE: To explore the effect of diode laser in the treatment of sinus chronic apical abscess. METHODS: A total of 78 patients with sinus chronic apical abscess were randomly divided into experimental group and control group, 39 cases in each group. Patients in the control group were treated with conventional root canal preparation and calcium hydroxide sealant. After conventional root canal preparation, the canals in the experimental group were disinfected with diode laser and then calcium hydroxide sealant. SPSS 19.0 software package was used for data analysis. RESULTS: Of 39 patients in the experimental group, only 1 sinus was not healed,the total effective rate was 97.44%;Of 39 patients in the control group,9 sinuses were not healed, the total effective rate was 76.92%. The difference between the two groups was statistically significant. CONCLUSIONS: The results show that the effect of diode laser in the treatment of sinus chronic apical abscess is better, which is worthy of wide application.

[Continuous observation of canal aberrations in S-shaped simulated root canal prepared by hand-used ProTaper files].

PURPOSE: To observe the formation of canal aberrations in S-shaped root canals prepared by every file of hand-used ProTaper. METHODS: Fifteen S-shaped simulated resin root canals were selected. Each root canal was prepared by every file of hand-used ProTaper following the manufacturer instruction. The images of canals prepared by S1, S2, F1, F2 and F3 were taken and stored, which were divided into group S1, S2, F1, F2 and F3. One image of canal unprepared was superposed with the images of the same root canal in these five groups respectively to observe the types and number of canal aberrations, which included unprepared area, danger zone, ledge, elbow, zip and perforation. SPSS12.0 software pakage was used for Fisher's exact probabilities in 2x2 table. RESULTS: Unprepared area decreased following preparation by every file of ProTaper, but it still existed when the canal preparation was finished. The incidence of danger zone, elbow and zip in group F1 was 15/15, 11/15, 4/15, respectively, which was significantly higher than that in group S2(2/15,0,0) (P<0.001). Ledge appeared after prepared by F2, and increased sharply in group F3. None perforation was found in all groups. CONCLUSIONS: The incidence of canal aberrations begins to increase after prepared by finishing files of ProTaper.The presence of unprepared area suggests that it is essential to rinse canal abundantly during complicated canal preparation and canal antisepsis after preparation.

[Investigation of influence on apical sealability generated by root canal sealer placement].

OBJECTIVE: To investigate the influence of sealer placement on apical sealability in root canal treatment. METHODS: 100 extracted single root canal teeth were selected. All canals were prepared by manual Protaper instrument in a step-back way. The samples were divided into 5 groups randomly. A group: 30 samples, sealer placement by chief gutta percha; B group: 30 samples, sealer placement by K file; C group: 30 samples, sealer placement by spreader; D group: 5 samples, a positive control; E group: 5 samples, a negative control. There were 2 subsets in each experimental group which were obturated by lateral gutta percha with or without sealer. Glucose oxidase method was used to measure the apical leakage at the 1st 2nd, 4th, 7th, 10th, 15th, 20th, 25th, 30th day of the experiment. RESULTS: Apical sealability varied with different sealer placement methods (F=4.832, P=0.001). Sealer placement by chief gutta percha (A group) had the best instant apical sealability. However, lateral gutta percha with or without sealer didn't affect the apical sealibility. CONCLUSION: Placing the same kind sealer in different ways can affect the apical sealability. There were no significant differences of the apical leakage no matter the lateral gutta percha with or without sealer. In order to get better instant apical sealability and simplify the clinic operation, placing the sealer with a chief gutta percha while the lateral gutta percha without sealer is recommended.