Effect of gallic acid addition on some mechanical properties of self-adhesive resin cements

Abstract Self-adhesive resin cements (RCs) activate matrix metalloproteinase (MMP) and cathepsin-related collagen degradation, and gallic acid (GA) inhibits the activity of both MMPs and cysteine cathepsins. The purpose of this study was to evaluate the setting time, biaxial flexural strength, and Vickers hardness of self-adhesive RCs after the addition of two different concentrations of GA. RelyX U200 (3M ESPE) and Panavia SA (Kuraray) were modified with 0.5 and 1 wt% GA. The setting time of five samples in each RC group was assessed using a thermocouple apparatus as described in the ISO 4049 test. Biaxial flexure strength was measured using a universal testing machine until failure. Vickers hardness was measured with three randomized indentations on the surface of each resin disc. RCs without GA were used as control. Data were analyzed using a one-way analysis of variance and Tukey's HSD test (α = 0.05). The setting times ranged from 2.4 to 4.6 min for RelyX and from 4.9 to 6.0 min for Panavia. The biaxial flexure strength ranged from 76.5 to 109.7 MPa for RelyX and from 73.3 to 108.2 MPa for Panavia. Vickers hardness values ranged from 41.6 to 58.6 for RelyX and 27.2 to 33.6 for Panavia. The addition of 0.5 and 1 wt% GA to improve durability of resin-dentin bonds had no adverse effects on setting time, whereas the biaxial flexure strength and Vickers hardness values for the tested materials were significantly reduced.

Effect of green tea as a protective measure against dental erosion in coronary dentine

Abstract The aim of this study was to evaluate the effect of green tea as a protective measure on eroded dentin. Disks of human coronary dentin were selected based on surface hardness and randomly assigned to 3 groups (n = 10): DW - distilled water, CHX - 0.2% chlorhexidine digluconate, and GT - green tea. The disks were allowed to acquire pellicle for 2 hours and were then subjected to 3 cycles per day of demineralization (C6H8O7 0.05 M, pH 3.75, 60 s), treatment (DW or CHX or GT, 5 min) and remineralization (artificial saliva, 60 min) over a period of 3 days. Changes in the dentin were determined by loss of surface hardness (%SHL) and mechanical profilometry analysis at the end of each day. Data were analyzed by two-way ANOVA followed by Tukey’s test for %SHL and profilometry (p < 0.05). Significant reductions in dentin hardness loss were observed only for the CHX group when compared to the DW group (p < 0.05). However, there was no significant difference between the CHX and GT groups (p > 0.05). A significant difference was observed between DW and GT treatments for wear and roughness measurements (p < 0.05). The green tea extract solution was able to reduce the wear and roughness caused by dentin erosion under the conditions of this study.

Perfil da resposta Th1/Th2 no fluido gengival de pacientes portadores de doença inflamatória intestinal com periodontite crônica / Th cell profile in the gingival crevicular fluid from inflammatory bowel disease patients with chronic periodontitis

O objetivo dessa tese foi avaliar a expressão de citocinas Th1 (IL-12 e INFγ), citocinas Th2 (IL-4, IL-6 e IL-10) e das citocinas pró-inflamatórias IL-18, IL-1β e TNFα no fluido gengival de pacientes com periodontite crônica portadores da doença de Crohn (DC), de retocolite ulcerativa idiopática (RCUI) e em indivíduos saudáveis (o grupo controle, GC). Como objetivo secundário, avaliamos a função dos neutrófilos no fluido gengival desses pacientes através da mensuração das metaloproteinases da matriz -8, -9 (MMP-8 e MMP-9) e da atividade da elastase. Quinze pacientes com DC (idade média 38.2 ± 11.4 anos), 15 pacientes com RCUI (idade média 45.0 ± 10.5 anos) e 15 pacientes saudáveis (idade média 42.1 ± 7.8 anos) participaram desse estudo. Todos os dentes presentes, com exceção dos terceiros molares, foram examinados. Profundidade de bolsa (PB), nível de inserção clínica (NI), presença de placa e de sangramento a sondagem foram avaliados em seis sítios por dente. Em cada paciente, o fluido de 4 sítios com periodontite (PB ≥ 5 mm e NI ≥ 3mm) e de 4 sítios com gengivite (PB ≤ 3 mm e NI ≤ 1 mm) foram coletados através de pontas de papel absorvente pré-fabricadas. O sistema LUMINEX® foi utilizado na mensuração das IL-1β, IL-4, IL-6, IL-10, IL-12p70, TNFα, INFγ, MMP-8 e MMP-9. A IL-18 foi analisada através do ensaio ELISA e a atividade de elastase através de uma reação enzimática. O soro desses pacientes também foi analisado e o coeficiente de correlação de Pearson foi utilizado na análise da correlação entre as citocinas no soro e no fluido gengival. Nos sítios com gengivite, a quantidade total de IL-4 foi significativamente menor no grupo RCUI do que no grupo GC (p=0.016). Nos sítios com periodontite, a quantidade total de IL-4 foi significativamente menor no grupo DC do que no grupo GC (p=0.029)...

The aim of this thesis was to evaluate the expression of Th1 cytokines (IL-12 and INF-γ), Th2 cytokines (IL-4, IL-6 and IL-10) and the pro-inflammatory cytokines IL-18, IL-1β and TNF-α in the gingival crevicular fluid (GCF) from Crohn’s disease (CD) patients, ulcerative colitis (UC) patients and healthy individuals (control group, CG) who had chronic periodontitis. Besides, we measured elastase activity, matrix metalloproteinase -8 and -9 (MMP-8 and -9) to address the neutrophil function in the GCF. Fifteen CD patients (mean age 38.2 ± 11.4 years), 15 UC patients (mean age 45.0 ± 10.5 years) and 15 systemically healthy controls (mean age 42.1 ± 7.8 years) were enrolled in this study. All the present teeth, except for the third molars were examined. Probing pocket depth (PPD), clinical attachment loss (CAL), presence of plaque and presence of bleeding on probing were assessed in six sites per tooth. In every subject, GCF from 4 gingivitis sites (PPD ≤ 3mm and CAL ≤ 1mm) and from 4 periodontitis sites (PPD ≥ 5mm and CAL ≥ 3mm) were collected with filter strips. The data were reported as total amount and concentration. IL-1β, IL-4, IL-6, IL-10, IL-12p70, TNFα, INFγ, MMP-8 and MMP-9 were analyzed by the Luminex® analyzer. IL-18 was analyzed using a commercially available ELISA assay and the elastase activity by an enzymatic reaction. The serum was also analysed and the correlations between the cytokines in the GCF and in the serum were calculated by Pearson correlation analysis. In gingivitis sites, the total amount of IL-4 was significantly lower in the UC group than in the CG group (p=0.016). In periodontitis sites, the total amount of IL-4 was significantly lower in CD group than in the CG group (p=0.029). The total amount of IL-4 was lower in UC group than in CD group (p=0.077)...

Alterations of E-cadherin and MMP-2 in cancer prostate

E-cadherin plays a crucial role in epithelial cell-cell adhesion and maintenance of tissue architecture. Alterations in expression or function of this protein result in loss of intercellular adhesion, with possible consequent increased tumor progression, metastasis, and poor prognosis in different cancer types. Matrix metalloproteinases [MMPs] constitute a multi-gene family of proteolytic enzymes that are capable of degrading connective tissue and almost all extracellular matrix components. Overexpression of MMPs is usually associated with the acquisition of invasiveness by tumor cells, cancer progression, angiogenesis and metastasis. To examine the expression of E-cadherin and MMP-2 in male prostatic lesions using immunohistochemical staining. 30 cases of formalin-fixed, paraffin embedded tissues of male prostatic lesions were examined for the expression of E-cadherin and MMP-2 using immunohistochemistry utilizing rabbit antihuman polyclonal antibodies for E-cadherin and MMP-2. The tissue specimens comprise samples of 25 prostatic adenocarcinoma [PAC] and five benign prostatic hyperplasia [BPH]. H and E histological examination revealed that of the 25 studied malignant cases, six were combined grade CG 10; three were CG9; two were CG8; three were CG7; four were CG6; and seven were CG5, according to combined Gleason's grading system. Immunostaining showed altered expression [cytoplasmic] of E-cadherin in poorly and moderately differentiated foci of carcinoma [CG6-10]. Cell membrane expression of E-cadherin was seen in well differentiated foci as well as in BPH. However for immunostaining of MMP-2, very weak expression of it was seen in BPH as well as in normal glands adjacent to tumor cells. Mild to moderate staining intensity was observed in well differentiated PAC and moderate intensity was seen in moderately differentiated PAC. Overexpression of MMP-2 in the form of positive cytoplasmic aggregates was shown in poorly differentiated PAC. The results suggest the implication of the altered expression of E-cadherin and MMP-2 in increased aggressiveness of the tumor with its subsequent increased invasiveness and progression. Also show that increased expression of collagenase type IV [MMP-2] and decreased expression of E-cadherin are associated with increasing Gleason score and that the expression of MMP-2 and E-cadherin exhibited strongest association with advanced prostate cancer

Tissue mRNA expression in rat of newly described matrix metalloproteinases

Matrix metalloproteinases (MMPs) comprise a large group of endoproteinases that degrade all protein components of the extracellular matrix. Functionally, MMPs contribute to several different physiological as well as pathological conditions. The number of newly described MMPs has increased in recent years, although current knowledge about their expression pattern in various tissues remains incomplete. Here we analyzed the relative mRNA expression of the most recently described MMPs _ MT5-MMP (MMP-24), MT6-MMP (MMP-25), MMP-27 and epilysin (MMP-28) _ in a broad selection of rat tissues using real time-PCR. MMP-24 mRNA was found to be widely expressed with predominance in the central nervous system. MMP-25 mRNA, in contrast, exhibited peak expression levels in testis, kidney and skeletal muscle, differing from previously described distribution patterns in humans. mRNAs for MMP-27 and MMP-28 were generally expressed at a lower level. All four MMPs studied were detected at higher mRNA levels in bone and kidney, suggesting a possible role of these MMPs in physiological processes within these two organs. The present study highlights the differential distribution pattern of newly described MMPs among different tissues and underlines differences in the mRNA expression between different species.

Alkaline phoshatase, tumor necrosis factor-alpha and matrix metalloproteinase-8 in crevicular fluid from peri-implantitis versus chronic periodontitis patients

Peri-implantitis is an inflammatory reaction affecting the tissues surrounding osseointegrated dental implants resulting in loss of supporting bone. Recent advances in the understanding of biologic events involved in the pothogenesis of periodontitis indicating that bone mediators e.g. tumor necrosis factor-alpha [TNF-alpha], alkaline phosphatase [ALP] and matrix metalloproteinase-8 [MMP-8] may also be operating in the pathogenesis of peri-implantitis. This study aimed to explore whether pro-inflammatory mediator TNF-alpha and markers of bone loss; ALP and MMP-8 in per-implant crevicular fluid [PICF] provide a diagnostic information as to the status of the implant. The present study evaluated 11 implants in patients having peri-implantitis and 12 without implantitis as compared to 12 patients with chronic periodontitis. The clinical assessment for all patient groups included pocket depth [PD], plaque index [PI] and gingival index [GI]. There were significant differences [p<0.05] in PI, PD and GI in peri-implantitis and periodontitis patient groups as compared to healthy implant group, while there were non significant difference between per-implantitis and periodontitis patient groups. ALP, MMP-8 and TNF-alpha were measured in gingival crevicular fluid [GCF] and PICF 2 years postoperatively. The ALP activity and MMP-8 concentration were significantly higher in periodontitis and peri-implantitis patients than healthy implant group [p<0.01, and p<0.05, respectively]. There were no statistically significant differences TNF-alpha concentration between the three study groups. There were no statistically significant differences in MMP-8 concentration and ALP activity between periodontitis group and patients with per-implantitis. The ALP activity showed a significant positive correlation with GI and PD [p<0.01]. In conclusion, the present results might suggest that ALP and MMP-8 in PICF has a possible role as a markers of peri-implantitis