Clinical evaluation of composite inlays in defective molars / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate clinical effect of composite inlays in the defective molars.</p><p><b>METHODS</b>A total of 200 defective molars from 163 patients were divided into two groups, including 100 molars of each. One group was restored with the direct composite inlays and another group with the traditional composite fillings. All the restorations were evaluated in oral cavity after 6-month and 5-year filling or insertion with United States public health service criterions. The data were analyzed using SPSS 11.0 software with the chi-square test. The significance level was set at 5%.</p><p><b>RESULTS</b>In clinical service for 6 months, the successful rate of composite inlays was 91.8% (90/98) and the corresponding figure for traditional composite fillings was 91.8% (89/97), but there was no statistically significant difference (P > 0.05). In clinical service for 5 years, the successful rate of composite inlay was 87.9% (80/91), the corresponding figure for the traditional composite fillings being 67.4% (60/89) and the difference was statistically significant (P < 0.05).</p><p><b>CONCLUSIONS</b>In clinical, the defective molars can be well restored with the direct composite inlays. Especially in the long-term clinical service, the composite inlays show significant superiority over the traditional composite fillings.</p>

Effect of fibrinogen on the secretion of interleukin-1beta and - 8 by polymorphonuclear leukocytes / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of one of the acute-phase proteins, fibrinogen, on the release of IL-1beta and -8 by human peripheral polymorphonuclear leukocytes (PMN) and the possible role of fibrinogen during the destruction of periodontium.</p><p><b>METHODS</b>Peripheral PMN were isolated by discontinuous density gradient centrifuging technique. The freshly isolated PMN were suspended in Hank's balanced saline solution (1 x 10(9)/L) supplemented with 0.5% BSA and 0.1% glucose. The levels of IL-1beta and -8 in the supernatants produced by cultured cells upon the addition of human fibrinogen at different concentrations were measured by ELISA technique.</p><p><b>RESULTS</b>Incubated with human fibrinogen at 2 g/L or 10 g/L for different time periods, human peripheral PMN released significantly greater amount of IL-1beta [(10.41 +/- 0.37) - (35.86 +/- 0.30) ng/L or (22.81 +/- 0.45) - (57.77 +/- 2.08) ng/L] and IL-8 [(93.90 +/- 13.95) - (2045.66 +/- 53.03) ng/L or (115.02 +/- 10.61) - (3858.69 +/- 25.65) ng/L] than PMN without the stimulation of fibrinogen (IL-1beta, P < 0.001, and IL-8, P < or = 0.016). The higher concentration of fibrinogen or the longer treatment time, the higher levels of IL-1beta and -8 were released by PMN (P < 0.001).</p><p><b>CONCLUSIONS</b>Fibrinogen induced the secretion of pro-inflammatory cytokines IL-1beta and -8 by PMN and may be involved in magnification of the inflammatory response of periodontium and bone resorption.</p>

Correlation between levels of fibrinogen, beta455 g/A fibrinogen gene polymorphism and chronic periodontitis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the relationship between plasma levels of fibrinogen, the-beta455 G/A fibrinogen gene polymorphism and the severity of periodontal inflammation and to explore the possible role of fibrinogen in the association of periodontitis with coronary heart disease (CHD).</p><p><b>METHODS</b>A total of 121 patients with moderate to severe periodontitis and periodontally healthy and gingivitis controls were enrolled in the study. Peripheral blood samples were collected and the plasma fibrinogen levels were determined by the clotting method of Clauss. Polymerase chain reaction and restriction fragment length polymorphism analysis with Hae III were used to examine the -beta455 G/A fibrinogen gene polymorphism.</p><p><b>RESULTS</b>Fibrinogen levels were significantly higher in moderately or severely chronic periodontitis patients [(3.45 +/- 0.68) g/L] than periodontally healthy and gingivitis controls [(2.47 +/- 0.42) g/L, P < 0.001]. The carrier status of the A allele at position -455 in the beta fibrinogen gene was associated with elevated fibrinogen levels and the frequency of the-A455 allele in the beta fibrinogen gene in the patient group was significantly higher than in the control group (P = 0.032). Carriers of the -A455 allele were about 3-fold more likely to have moderate or severe periodontitis as compare to individuals without the -A455 allele( OR = 3. =135, P= 0.008).</p><p><b>CONCLUSIONS</b>Fg-beta455 G/A polymorphism may contribute to the elevated plasma fibrinogen levels and put individuals at higher risk of having severe periodontitis. As the independent risk factor of CHD, fibrinogen levels and Fg-beta455 G/A polymorphism may play a role in the pathogenesis of periodontitis.</p>

Study of the correlation between moderately and severely chronic periodontitis and coronary heart disease / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the correlation between moderately and severely chronic periodontitis and coronary heart disease, as well as the role of fibrinogen in the mechanisms responsible for the correlation between periodontitis and coronary heart disease.</p><p><b>METHODS</b>95 subjects who were systemic health or patients of coronary heart disease with or without periodontitis were enrolled. All the subjects were placed into 4 groups based on their periodontal status and cardiovascular health. The 4 groups were healthy control group (HC), moderately and severely chronic periodontitis group (MSP), coronary heart disease group(CHD), and MSP coexisted with CHD group (MSP+CHD). Clinical periodontal index were examined, at the same time, plasma fibrinogen levels and serological changes used in diagnosing of cardiovascular disease routinely were determined. ANOVA and ANCOVA were used in the statistical analysis.</p><p><b>RESULTS</b>Fibrinogen levels of HC, MSP, CHD, and MSP+CHD group were (2.36+/-0.37), (3.63+/-0.73), (4.08+/-0.84), and (4.14+/-0.96) g/L, respectively. Fibrinogen levels of MSP and MSP+CHD group were significantly higher than that of healthy controls (P<0.01). The patients with moderately to severely chronic periodontitis were more likely to have coronary heart disease as compared to periodontally healthy controls (OR=2.527, P=0.047) after adjusted for blood pressure and body mass index.</p><p><b>CONCLUSION</b>Moderately and severely chronic periodontitis maybe a risk factor of coronary heart disease and fibrinogen could be one of the biological basis which links periodontitis with coronary heart disease.</p>

Differential analyses of mRNA expression of gtfs from Streptococcus mutans in different pH condition / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To determine the expression level of each gtf under different pH cultural conditions and to find the relationship between gtf expression levels with environmental pH in different strains of Streptococcus mutans (S.mutans).</p><p><b>METHODS</b>S. mutans form clinical isolation with different extracellular polysaccharides (EPS) producibility and UA159 were selected. Their ability to produce EPS under pH5.5 and pH7 were tested. Then in two strains, the relative quantity of gtfA, gtfB, gtfC, gtfD's mRNA which were related to S. mutan's ability to produce EPC, were examined by real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) methods under different pH culture condition.</p><p><b>RESULTS</b>At pH5.5, expression levels of gtfA, gtfB, gtfD were increased while that of gtfC were decreased in both strains, and that of gtfB, gtfC were higher in strain which produces more ECP.</p><p><b>CONCLUSION</b>The expression levels of gtfs related closely to the cariogenicity of S. mutan.</p>

Interleukin-8 regulations of oral epithelial cells by porphyromonas gingivalis with different fimA genotypes / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The expression of heterogenic virulence properties depends on its clonal diversity. The aim of the study was to investigate the mechanism of interleukin-8 (IL-8) regulations of oral epithelial cells by challenge of Porphyromonas gingivalis (P. gingivalis) with different fimA genotypes, discuss the relation between fimA genotype and its pathogenicity.</p><p><b>METHODS</b>P. gingivalis ATCC 33277 (type I), W83 (type IV), 47A-1 (type IV) were assessed for their inductions of IL-8 expression in human oral epithelial cells (KB cell line, ATCC CCL-17). KB cells without stimulation of P. gingivalis were used as control group. IL-8 mRNA expression was de termined by reverse transcription polymerase chain reaction (RT-PCR) at different time intervals (1, 3, 6, 24 h) following continuous co culture of bacteria with KB cell line, and IL-8 protein levels in culture supernatant was determined by enzyme-linked immunosorbent assay.</p><p><b>RESULTS</b>IL-8 mRNA levels were up-regulated and reached its high peak at 1 h following both genotypes infection, then decreased to base level till 24 h. Attenuation of IL-8 protein levels was down-regulated when KB cell co-cultured with both genotypes for 3 h till 24 h, and type IV was lower than type I. IL-8 and IL-6 mRNA expression were not consistent with their protein levels, which indicated post-transcriptional regulations.</p><p><b>CONCLUSION</b>fimA genotypes of P. gingivalis are related with the effect of IL-8 inductions, which indicates fimA genotype is associated with pathogenesis of P. gingivalis.</p>

Genetic diversity of F-ATPase subunits gene uncEBF amplified from Streptococcus mutans clinical isolates / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The purpose of this research was to study the genetic diversity of F-ATPase subunit gene uncEBF derived from Streptococcus mutans (S. mutans) clinical isolates, furthermore to investigate the relationship between the genetic diversity of F-ATPase and S. mutans aciduric ability.</p><p><b>METHODS</b>38 S. mutans strains included 18 high acid tolerance strains and 20 low acid tolerance strains. Gene uncEBF of these isolates were amplified with specific primers from S. mutans genomic DNA, and the PCR products were analyzed by RFLP and sequenced. SPSS 11.0 statistic software assayed the results.</p><p><b>RESULTS</b>It was testified that two genotypes A and B of PCR-RFLP were revealed when digested with Alu I and Dde I digested fragments of uncEBF displayed two different patterns C and D. Fisher exact two-tail test showed that the distributions of A and B genotype strains with different acidurance were different (P < 0.05), and the proportion of A genotype strains from high acidurance group was higher than that from low acidurance one. Some of these amplified uncEBF genes from different genotype were sequenced and testified that there existed variation of Alu I and Dde I recognized sites.</p><p><b>CONCLUSION</b>This study indicated that uncEBF gene of S. mutans F-ATPase obviously exhibited genetic diversity.</p>

Genetic diversity and mRNA expression of F-ATPase subunit uncG gene of streptococcus mutans clinical isolates / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the genetic diversity and the gene expression of membrane-bound proton-translocating ATPase (F-ATPase) subunit gene uncG derived from Streptococcus mutans (S. mutans) clinical isolates.</p><p><b>METHODS</b>38 S. mutans strains derived from caries-active and caries-free individuals including 18 strains displaying high acid tolerance and 20 strains displaying low acid tolerance. Gene uncG was amplified with specific primers from S. mutans genomic DNA, then the PCR product was analyzed by RFLP and sequenced. The relative expression quantity of uncG gene against the housekeeping gene recA was determined by using RT-PCR method. A gel documentation system and QUANTITY ONES software were used to analyze the data results.</p><p><b>RESULTS</b>It was testified that four genotypes A, B, C and D of PCR-RFLP were revealed when respectively digested with Alu I and Bsr I, but the distributions of the four genotype strains showed no difference (P > 0.05). The differences of uncG gene transcript quantities derived from different genotype or different aciduranc strains had no significance (P > 0.05).</p><p><b>CONCLUSION</b>This study indicated that uncG gene of F-ATPase obviously displayed genetic diversity and existed polymorphism at mRNA expression level, while the Alu I-RFLP genotypes and the expression levels would not be responsive to different acid tolerance of S. mutans strains.</p>

The expression and activity of alkaline phosphatase in human periodontal ligament cells with nanometer hydroxyapatite / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of nanometer hydroxyapatite on the proliferation and the osteogenetic differentiation of periodontal ligament cells (PDLC).</p><p><b>METHODS</b>Nano-hydroxyapatite powders were fabricated with sol-gel method. The fourth passage periodontal ligament cells were cultured with nanometer hydroxyapatite powder (nano-HA), dense hydroxyapatite powder (dense-HA) and only medium as control respectively. On the 5th, 8th day of culture, the osteogenetic differentiation of human periodontal ligament cells was evaluated though alkaline phosphatase (ALP) activity, ALP immunohistochemical stain and ALP positive flow cytometry.</p><p><b>RESULTS</b>There were significant differences among nano-HA group, dense-HA group and control group on the 5th and 8th day of culture. A majority of nano-HA group and dense-HA group cells sample showed positive ALP stain. But the ALP positive stain of nano-HA group cells sample was denser than that of dense-HA group. In FCM, the distribution of ALP positive cells cultured with nanoparticles were significantly more than that of other groups.</p><p><b>CONCLUSIONS</b>The nano-HA, as a calcium phosphate biomaterial, has ability to promote the activity of osteogenetic differentiation for periodontal ligament cells compared with dense-HA.</p>

Effect of fibrinogen on the adherence of Porphyromonas gingivalis to human oral epithelial cells / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study the role of fibrinogen molecule in the pathogenesis of periodontal diseases.</p><p><b>METHODS</b>An in vitro cell culture model was used. Methyl-(3)H Thymidine radiolabeled Porphyromonas gingivalis (Pg) ATCC 33277 were examined for their ability to adhere to and invade the confluent monolayers of human oral epithelial KB cells with or without exogenous human fibrinogens by scintillation spectrometry.</p><p><b>RESULTS</b>The addition of exogenous fibrinogens made more amount of and higher ratios of adhesive and invasive Pg, in contrast to the group without exogenous fibrinogen (P < 0.001). At different concentrations of exogenous fibrinogen, the amount and ratios of adhesive and invasive Pg varied significantly (P < or = 0.007). The higher concentrations of exogenous fibrinogen was added, the greater amount and ratios of adhesive and invasive Pg were found.</p><p><b>CONCLUSIONS</b>Fibrinogen promotes the adherence of Pg to human oral epithelial cells and may play an important role in the pathogenesis of periodontal diseases.</p>