Effects of different concentrations of sodium hypochlorite on dentine adhesion and the recovery application of sodium erythorbate / 中南大学学报(医学版)

OBJECTIVES@#Root canal therapy is the most effective and common method for pulpitis and periapical periodontitis. During the root canal preparation, chemical irrigation plays a key role. However, sodium hypochlorite (NaOCl), the widely used irrigation fluid, may impact the bonding strength between dentin and restorative material meanwhile sterilization and dissolving. Therefore, it's important to explore the influence of NaOCl on the adhesion between dentin and restoration materials to ensure clinical efficacy. This study aims to explore the effect of NaOCl on dentine adhesion and evaluate the effect of dentine adhesion induced by sodium erythorbate (ERY), and to provide clinical guidance on dentin bonding after root canal therapy.@*METHODS@#Seventy freshly complete extracted human third molars aged 18-33 years old, without caries and restorations were selected. A diamond saw was used under running water to achieve dentine fragments which were divided into 10 groups with 14 fragments in each group: 2 control [deionized water (DW)±10% ERY] and 8 experimental groups (0.5%, 1%, 2.5%, and 5.25% NaOCl±10% ERY). The dentine specimens in the control group (treated with DW) and the experimental groups (treated with 0.5% NaOCl, 1% NaOCl, 2.5% NaOCl, and 5.25% NaOCl) were immersed for 20 min using corresponding solutions which were renewed every 5 min. The other 5 groups were immersed in 10% ERY for 5 min after an initial washing with DW for 1 min. Then, we selected 4 dentine fragments from all 14 fragments in each group and the numbers and diameters of opening dentinal tubules were observed under scanning electron microscope (SEM). The other 10 dentine fragments from each group were used to make adhesive samples by using self-etch adhesive wand composite resin. All the above adhesive samples were sectioned perpendicular to the bonded interface into 20 slabs with a cross-sectional area of 1 mm×1 mm using a diamond saw under the cooling water, and then the morphology of 10 slabs in each group's bonding interface was observed from aspects of formation of resin tags, depth of tags in dentin, and formation of hybrid layer under SEM. The other 10 slabs of each group's microtensile bond strength and failure modes were also analyzed.@*RESULTS@#Among the 0.5% NaOCl, 1% NaOCl, 2.5% NaOCl, and 5.25% NaOCl groups, the number and diameter of patent dentinal tubules gradually increased with the rise of concentration of NaOCl solution (all P<0.05). Among the DW, 0.5% NaOCl, 1% NaOCl, 2.5% NaOCl, and 5.25% NaOCl groups, the number and diameter of patent dentinal tubules increased after using ERY, but without significant difference (all P>0.05). Among the DW, 0.5% NaOCl, 1% NaOCl, and 2.5% NaOCl groups, the scores of formation of resin tags under SEM gradually increased with the increase of concentration of NaOCl solution, while the score in the 5.25% NaOCl group decreased significantly compared with the score of the 2.5% NaOCl group (P<0.05). There was no significant difference between using 10% ERY groups and without using 10% ERY groups (all P>0.05). The scores of length of the tags under SEM in the 5.25% NaOCl group was significantly higher than the scores of DW, 0.5% NaOCl, and 1% NaOCl groups (all P<0.05), and it was also higher than the score of the 2.5% NaOCl group, but without significant difference (P>0.05). There was no significant difference between using 10% ERY groups and without using 10% ERY groups (P>0.05). The scores of formation of hybrid layer under SEM in the 2.5% NaOCl and 5.25% NaOCl groups significantly decreased compared with the score of the DW group (all P<0.05). There were significant differences between the 2.5% NaOCl±10% ERY groups and between the 5.25% NaOCl±10% ERY groups (all P<0.05). Microtensile bond strength was greater in the 0.5% NaOCl, 1% NaOCl, and 2.5% NaOCl groups, but lower in the 5.25% NaOCl group than that in the DW group (all P<0.05). There were significant differences between the 2.5% NaOCl±10% ERY groups and between the 5.25% NaOCl±10% ERY groups (all P<0.05). The incidence of type "Adhesive" of failure modes in the 5.25% NaOCl group was significantly higher than that in other groups (all P<0.05), while the incidence of type "Adhesive" in the 5.25% NaOCl+10% ERY group was lower than that in the 5.25% NaOCl group (P<0.05).@*CONCLUSIONS@#The bonding strength to dentine increases with the increase of NaOCl concentration when the concentration lower than 2.5%; whereas it is decreased at a higher concentration (such as 5.25%). 10% ERY has a definite recovery effect on attenuated bonding strength to 5.25% NaOCl-treated dentine.

Clinical analysis for oral mucosal disease in 21 972 cases / 中南大学学报(医学版)

To analyze the incidence and distribution of oral mucosal diseases in Hunan Province and provide reference for prevention and treatment.
 Methods: The clinical data for all patients, who were treated in Xiangya Hospital of Central South University from April 2013 to March 2017, were collected. After screening, weighing and classifying, sex and age distribution for the disease was analyzed.
 Results: The female with the age between 40 to 49 were in the majority among 21 972 patients. The ratio between men to women was 1:1.05. According to the classification of diseases, the most common diseases were as follows: recurrent aphthous ulcer (27.17%), burning mouth syndrome (15.72%), oral submucous fibrosis (14.75%), oral lichen planus (10.38%), oral leukoplakia (4.21%), traumatic ulceration (4.14%), chronic cheilitis (3.47%), oral fungal infection (3.26%), and atrophic glossitis (2.74%). Recurrent oral ulcer (28.65%), burning mouth syndrome (23.70%) and oral lichen planus (13.31%) were the most common 3 kinds of oral mucosal diseases during females in Hunan. Oral submucous fibrosis was the most common oral mucosal disease among males in Hunan (28.56%).
 Conclusion: Recurrent oral ulcer, burning mouth syndrome and oral lichen planus are very popular in women in Hunan Province, and oral submucous fibrosis is the most common disease in male in this region. It shows a high trend of incidence in the surrounding provinces.

The expression of wnt1 in oral submucous fibrosis / 实用口腔医学杂志

Objective:To observe the expression of wnt1 in patients with oral submucous fibrosis(OSF) before and after treatment.Methods:40 patients with OSF were treated with triamcinolone acetonide combined with salvia miltiorrhiza,Before and after 4 weeks treatment,pain score of VAS and mouth opening(MO) were examined.wnt1 protein in saliva and gingival crevicular fluid(GCF) was examined by ELISA,wnt1 mRNA expression in buccal mucosa tissue was examined by real-time fluorescent quantitative PCR.20 healthy subjects were served as the controls.Results:The expression of wnt1 in OSF group[buccal tissue RT-PCR (36.89 ± 10.40) × 10-5,saliva ELISA (61.61 ± 4.45) ng/L,GCF ELISA (56.20 ± 3.65) ng/L] were significantly higher than that of control group [buccal tissue RT-PCR (4.63 ± 1.53) × 10-5,saliva ELISA (40.26 ± 3.00) ng/L,GCF ELISA (53.45 ± 1.74) ng/L)] (P ＜ 0.01).In OSF group,after treatment VAS was decreased(P ＜0.01),MO increased(P ＜0.01)),Buccal mucosa wnt1 mRNA level was positively correlated with wnt1 protein in saliva and GCF,negativity with MO (P ＜ 0.05),saliva wnt1 was positively correlated with VAS and GCF wnt1,negitively with MO(P ＜ 0.05).Conclusion:Wnt1 might take part in the occurrence and development of OSF.The detection of wnt1 in saliva and GCF might be a noninvasive method for the evaluation of OSF treatment.

Bactericidal effects and smear layer removal of Er∶YAG-laser radiation against Enterococcus faecalis in root canals / 中南大学学报(医学版)

Objective:To evaluate the cleaning ability of Er∶YAG laser against Enterococcus faecalis in root canals.Methods:The single-rooted human teeth were sterilized and inoculated with Enterococcusfaecalis and were randomly assigned into 2 groups.A group of teeth was irrigated with saline during root canal preparation while another group with NaClO.After mechanical preparation,the two groups were randomly divided into 3 subgroups according to the different treatments:Samples,laser radiation,and calcium hydroxide intracanal medication for 7 days.Bactericical effects were compared among groups.Root canal walls and dental tubules were observed under scanning electron microscope.Results:Er∶YAG laser was the most efficient way for anti-bacteria among the groups (P＜0.05),but there was no significant difference between the 2 laser groups (P＞0.05).Meanwhile the smear laser was efficiently removed by laser compared with other treatments,and the laser could open the dentinal tubules.Conclusion:Er∶YAG laser can be effectively used for root canal disinfection without NaClO and Ca(OH)2.

Isolation and gene screening for collagen phagocytic subpopulation of fibroblasts and non-collagen phagocytic subpopulation of fibroblasts / 中南大学学报(医学版)

OBJECTIVE@#To isolate the collagen phagocytic subpopulation of fibroblast (CPSF) and non-collagen phagocytic subpopulation of fibroblast (nCPSF) and to identify their differentially expressed genes.
@*METHODS@#The CPSF and nCPSF was isolated by using collagen-fluorescein-isothiocynate-latex bead (COL-FITC-LB) phagocytosis technique and FCM sorting method. Microarray analysis was used to screen the differentially expressed genes, which were verified by real-time PCR. 
@*RESULTS@#CPSF and nCPSF was successfully isolated. Seventeen differentially expressed genes were identified. Compared with nCPSF, the expression of 12 or 5 genes was up-regulated or down-regulated in CPSF. Three of the 12 up-regulated genes were urokinase plasminogen activator receptor-associated protein (uPARAP), cytochrome b-245, beta polypeptide (CYBB) and Hook homolog 1 (HOOK1), which were confirmed by real-time PCR. uPARAP mRNA expression level in CPSF was 2788 times of that in nCPSF. CYBB mRNA expression in CPSF was only 0.85 times of that in nCPSF. HOOK1 mRNA expression in CPSF was 1.96 times of that in nCPSF (P<0.05). 
@*CONCLUSION@#A novel method is successfully established to isolate CPSF and nCPSF. uPARAP is the main differentially expressed gene in CPSF and nCPSF, which is obviously involved in the fibroblast collagen phagocytosis. It might be a potential biomarker for treatment of collagen diseases.

Effect of the morphology of S-shaped root canals with reciprocating single file system on root canal irrigation / 中南大学学报(医学版)

Objective: To evaluate effect of the morphology of simulated S-shaped root canals with Reciproc or Mtwo instruments on root canal irrigation. Methods: A total of 40 simulated S-shaped resin blocks were randomly divided into 2 groups (n=20), which was prepared by Reciproc or Mtwo. Blue ink was injected with constant speed and volume into the canals using 30G lateral opening syringe. hTe distance from needle tip to apex and vapor lock length were measured. A type of 25# 0.04 gutta-percha point was used to stir and remove the vapor lock. hTe time for removal of the vapor lock was recorded. Another syringe was used to inject saline into the canals and to measure the length of stagnant water. Results: hTe distance from needle tip to apex in the Reciproc group was signiifcantly longer than that in the Mtwo group [(4.276 ± 0.221) mm vs (3.459 ± 0.205) mm,P<0.05]. The vapor lock length in the Reciproc group was signiifcantly longer than that in the Mtwo group [(4.472 ± 0.230) mm vs (3.668±0.217) mm,P<0.05]. hTe time to remove vapor lock was signiifcantly shorter in the Reciproc group than that in the Mtwo group [(10.13 ± 1.79) s vs (15.29 ± 2.15) s,P<0.05]. The length of stagnant water was also shorter in the Reciproc group than that in the Mtwo group[(1.351 ± 0.142) mm vs (2.245 ± 0.206) mm,P<0.05]. Conclusion: hTe morphology of S-shaped root canal affects the root canal irrigation. hTe effect of root canal irrigated by Reciproc is better than that by Mtwo.

Emphasis on the Construction of the Stomatology Experimental Teaching and the Cultivation of Students' Innovative Ideology / 中华医学教育探索杂志

In order to strengthen the stomatology experiment teaching,mehods such as constructing the stomatology experimental teaching platform,improving teaching methods and reforming the system of exam and assessment were adopted.Through these measures,opration and the innovative ideology of students were obviousely enhanced,students' interest were estimulated,the innovative spirit was enlightened and the comprehensive potential ability was developed.

Analysis of test paper of Endodontics on the Seven-Year-Program Stomatologic Students / 中华医学教育探索杂志

We analyzed the final test paper of Endodontics among the 2001th grade students of the seven-year-educational mode in our university.The results indicate that the test paper has standard form,reasonable distribution of content,moderate quantity of questions and comprehensive test items.showing that most students mastered the basic principles and knowledge of this course,reflecting satisfactory teaching effect.

Expression of u-PA and PAI-1 in oral submucous fibrosis / 实用口腔医学杂志

Objective:To investigate the expression of u-PA and PAI-1 and their possible role in oral submucous fibrosis(OSF). Methods:Immunohistochemistry and imaging analysis were used to detect the expression of u-PA and PAI-1 in 30 cases of OSF and 10 cases of normal control.Results:The expression of u-PA and PAI-1 was observed in the cytoplasm of blood vessel endothelium,fibroblasts and inflammatory infiltration cells in lamina propria of OSF and control samples.u-PA expression was increased at the early stage of OSF(P0.05).PAI-1 expression was increased following the development of the disease(P

Effects of tumor necrosis factor-? and interferon-? on proliferation of oral submucous fibrosis-derived fibroblasts / 实用口腔医学杂志

Objection: To investigate the effects of tumor necrosis factor-?(TNF-?)and interferon-?(IFN-?) on the proliferation of fibrobl asts from healthy persons(NM-FB) and patients with oral submucous fibrosis(OSF -FB).Methods: Fibroblast cultures were established from t he buccal mucosa of five healthy individuals and six patients with OSF. The effe cts of TNF-? and IFN-? on the proliferation of NM-FB and OSF-FB were studi ed by MTT colorimetric assay.Results: TNF-? at 100～10 0 00 U/ml stimulated NM-FB and OSF-FB proliferation (P

The effects of Streptococcus sobrinus on corrosion behavior of metal-ceramic alloys / 实用口腔医学杂志

Objective:To study the corrosion resistance of four metal-ceramic alloys in the presence of Streptococcus sobrinus, and to compare the effects of bacteria action in liquid and solid environment.Methods:Four metal-ceramic alloys were exposured to BHIA or BHI media with or without Streptococcus sobrinus and served as different groups. After inoculating 10 weeks, their I_ corr ,E_ corr ,E_ tp through cyclic polarization curves were obtained through Corrview 2 corrosion analyses software;and their surface changes after electrochemical corrosion were observed by field emission scanning electron microscopy (FESEM).Results:The E_ corr of four alloys were decreased in presence of oral microorganism, and the declines were more remarkable in BHI with bacteria. SEM observation showed the pittings in their surface.The corrosion resistance in BHI without bacteria were significant increased than that in the blank control. Conclusion:Streptococcus sobrinus can promote the corrosion behavior of metal-ceramic alloys and the corrosion resistance is more worse in BHI than BHIA with bacteria.