MMP-2 assay within the hybrid layer created by a two-step etch-and-rinse adhesive: biochemical and immunohistochemical analysis.

Objective: Degradation of hybrid layers (HLs) within resin-infiltrated dentine results from multiple degradation factors, including collagenolytic activity of specific matrix metalloproteinases (MMPs). Inhibition of host-derived MMPs may, therefore, slow the degradation of HL. The null hypothesis tested is that the presence of MMP-2 is similar regardless of chlorhexidine (CHX) pre-treatment or the use of an adhesive.

Immunohistochemical and biochemical assay of MMP-3 in human dentine.

Objective: The function of endogenous MMP-3 and its distribution within the human dentine is unclear. Thus, the aim of the present study was to assay the presence and distribution of MMP-3 within human sound dentine by means of biochemical and immunohistochemical assays.

Methods: Powdered dentine from extracted human teeth was prepared and (1) partially demineralised with 1% H(3)PO(4) for 10min or (2) untreated (control).

pPKCδ activates SC35 splicing factor during H9c2 myoblastic differentiation.

Although Protein Kinase C (PKC) isoforms' role in the neonatal and adult cardiac tissue development and ageing has been widely described "in vivo", the interaction of such enzymes with specific nuclear substrates needs to be investigated. The aim of our research has been the study of the expression, localization and interaction with the splicing factor SC35 of PKC isoforms (α, δ, ε, ζ) and their potential role in modulating the transcription machinery. H9c2 cells induced to myoblast differentiation in the presence of 1% Horse Serum (HS) have represented our experimental model.

Cytotoxic activity of guaiazulene on gingival fibroblasts and the influence of light exposure on guaiazulene-induced cell death.

Guaiazulene (GA) is widely used as a natural ingredient in many health care products and solutions. Although it has been reported to have interesting biological effects, GA and azulene derivatives have been proven to be cytotoxic against normal human cells and human tumor cells; moreover, guaiazulene has shown photomutagenic properties on bacterial strains. Therefore, we evaluated and compared the cytotoxicity of GA at different concentrations on human gingival fibroblast (HGF) cell cultures under normal conditions and under UV irradiation (UV-A dose: 6.

Suppression of procollagen {alpha}1 type 1 by long-term low-dose exposure to 2-hydroxyethylmethacrylate in human gingival fibroblasts in vitro.

The purpose of this study was to evaluate the cytotoxicity of low doses and long-term exposure to 2-hydroxyethylmethacrylate (HEMA) on the protein expression of human gingival fibroblasts (HGFs). Human gingival fibroblasts were exposed to different concentrations of HEMA ranging from 0.5 mmol/L to 3 mmol/L for periods of time from 72 hours to 2 weeks.

The diagnosis of the cause of the death of Venerina.

Venerina (little Venus) is the name given to a wax model representing a pregnant young woman that was created in Florence (Italy) by Clemente Susini (1754-1814) in 1782. It is currently located in the historic Science Museum of the University of Bologna. The model was constructed so as to enable removal of the thoracic and abdominal walls and various organs, exposing the heart, diaphragm and an opened uterus with a well-developed fetus.

Analysis of differential artificial ageing of the adhesive interface produced by a two-step etch-and-rinse adhesive.

This study was performed to evaluate the effects of different in vitro ageing techniques on the dentine-bonded interface produced by a two-step etch-and-rinse adhesive. Composite build-ups were bonded to sectioned human molars using XP BOND and cut into non-trimmed dentine-composite beams for microtensile testing. Beams were assigned to one of the following storage conditions: (i) artificial saliva, 24 h (control); (ii) 10% sodium hypochlorite (NaOCl), 1 h; (iii) 10% NaOCl, 3 h; (iv) 60,000 thermal cycles, 2 months; (v) artificial saliva, 2 months; (vi) 60,000 thermal cycles, 6 months; and (vii) artificial saliva, 6 months.

Push-out stress for fibre posts luted using different adhesive strategies.

The influence of thermocycling on the bond strength of fibre posts cemented with different luting approaches was investigated. A total of 84 human incisors were selected for the study. Sixty teeth were assigned to one of the following adhesive/cement combinations for push-out bond-strength evaluation: group 1, XP Bond/CoreXFlow + DT Light-Post; group 2, Panavia F 2.

Influence of a commercial tattoo ink on protein production in human fibroblasts.

Tattooing is an ancient art and is still widely practiced all over the world. Since the biocompatibility of tattoo dyes has not been well researched, we studied the toxicity of a commercial tattoo ink, commonly used in tattoo lab and esthetic centers, on human fibroblasts. To test cell viability, MTT assays were carried out and scanning electron microscopy to visualize changes in the cell surface after the dye exposure was performed.

Involvement of nuclear PLCbeta1 in lamin B1 phosphorylation and G2/M cell cycle progression.

Inositide-specific phospholipase Cbeta1 (PLCbeta1) signaling in cell proliferation has been investigated thoroughly in the G(1) cell cycle phase. However, little is known about its involvement in G(2)/M progression. We used murine erythroleukemia cells to investigate the role of PLCbeta1 in G(2)/M cell cycle progression and screened a number of candidate intermediate players, particularly mitogen-activated protein kinase (MAPK) and protein kinase C (PKC), which can, potentially, transduce serum mitogenic stimulus and induce lamin B1 phosphorylation, leading to G(2)/M progression.

HEMA down-regulates procollagen alpha1 type I in human gingival fibroblasts.

2-Hydroxyethyl methacrylate (HEMA) can be released from restorative materials and diffused into the tooth pulp over long periods of time. Although cytotoxicity due to high concentrations of monomers has been well studied, little is known about the risk of chronic toxicity resulting from low concentrations. The purpose of the study was to evaluate the effects of a minor toxic concentration of HEMA in the synthesis and expression of procollagen alpha1 type I produced by human gingival fibroblasts (HGF).

Expression of procollagen alpha1 type I and tenascin proteins induced by HEMA in human pulp fibroblasts.

In the dental pulp extracellular matrix, the main macromolecules are collagenous proteins, non-collagenous proteins and proteoglycans. Regulated synthesis of the interstitial collagens, in particular, type I collagen, is important during development and wound healing but also in a number of pathological conditions. Tenascin is also a matrix protein highly expressed during development while it decreases in mature organs.

Effect of fixative on chromatin structure and DNA detection.

In this study, we analyzed the chromatin ultrastructure in interphase cells after different chemical fixations. In light of the fact that there is little information regarding the fixation of biological samples in combination with molecular biology methods (such as DNA extraction and in situ hybridization methods) we analyzed the ultrastructure of chromatin in interphase cells fixed with different fixatives and tested under the same conditions for both DNA extraction and in situ hybridization. The results showed that, among the different combinations and concentrations we analyzed, the solution of 4% paraformaldehyde/0.

Effects of citric acid and EDTA conditioning on exposed root dentin: An immunohistochemical analysis of collagen and proteoglycans.

Objective: Preservation of structural and biochemical properties of the root dentin matrix is crucial to favor healing and regenerative periodontal processes. Aim of this study was to evaluate the biochemical characteristics of collagen and chondroitin sulphate of root dentin surfaces exposed by periodontal disease after acid conditioning by means of an immunohistochemical technique.

Design: Human teeth scheduled for extraction due to periodontal reason were submitted to: (A) scaling and root planning; (B) ultrasonic instrumentation; (C) no instrumentation.

Nanoleakage within the hybrid layer: a correlative FEISEM/TEM investigation.

The aim of this study was to compare the nanoleakage patterns of the resin-dentin interfaces of three dentin bonding systems at both TEM and field emission in lens SEM (FEI-SEM) levels. A standardized smear layer was created with 180-grit silicon carbide paper (SiC) on dentin disks obtained from 18 noncarious human third molars. Specimens were randomly divided into three groups and bonded with a two-step total etching adhesive (Single Bond, SB), a two-step, self-etching adhesive (Clearfil SE BOND, SEB), and a one-step, self-etching adhesive (XENO III, XEIII).

Immunohistochemical analysis of collagen fibrils within the hybrid layer: a FEISEM study.

This study evaluated the immunohistochemical labeling pattern of dentin collagen fibrils within hybrid layers created by different bonding systems using high resolution SEM. Four different adhesive materials, including self-etching and total-etching systems, were examined: Prime & Bond NT, OptiBond SOLO Plus, Single Bond and Clearfil Protect Bond. All materials were applied to the dentin of extracted human third molars.

Effects of different acid and sodium hypochlorite treatments on dentin collagen: a FEISEM analysis.

Purpose: To evaluate if different acid treatments of dentin surface might remove different amount of mineralized dentin, thus exposing and modifying the CF network.

Methods: Dentin disks prepared from human third molars with a low-speed diamond saw were etched for 15 seconds with the tested acids: citric acid 10%, maleic acid 10%, 2.5% oxalic acid, 35% phosphoric acid and 24% EDTA gel.

Ultra-morphology of self-etching adhesives on ground enamel: a high resolution SEM study.

Purpose: To evaluate the effect of different commercial self-etching agents on enamel morphology using high-resolution in-lens scanning electron microscopy (FEISEM).

Methods: The bonding systems selected for the study were: Prime & Bond NT (no-etch technique), Prime & Bond 2.1 (no-etch technique), NRC/Prime and Bond NT, Syntac Single Component, Prompt L-Pop, F2000, and Clearfil SE Bond.

Morphological study of resin-dentin bonding with TEM and in-lens FESEM.

Purpose: To evaluate the morphological characteristics of the dentin-resin interface using high-magnification electron microscopy and correlate the TEM findings of resin-dentin interfaces with the corresponding in-lens Field Emission SEM (FEISEM) observation.

Methods: Twelve 800 microm-thick dentin disks were obtained from middle dentin and assigned to four groups: (1) a self-etching adhesive material, Clearfil SE Bond; (2) a solvent-free total-etch simplified adhesive, One Coat Bond; (3) an acetone-based total-etch simplified adhesive, Prime&Bond NT; (4) an acetone-based total-etch simplified adhesive, Prime&Bond NT, upon a short dentin deproteinization with 10% NaOCl gel (AD Gel) for 15 seconds. Disks were restored with a 1 mm thick layer of a low-viscosity composite.

Immunocytochemical identification of type I collagen in acid-etched dentin.

The hypothesis tested in this study is that the application of phosphoric acid prevents collagen fibrils (CF) from maintaining their structural morphology, as assessed by their immunochemical antigenicity. Dentin was conditioned with EDTA and with 35% H3PO4 for 15, 30, and 60 s. For a control there was no treatment.

Effect of dentinal pretreatments on coronal dentin primary carious lesions: a field emission SEM study.

The aim of the study was the morphological analysis of coronal dentin caries and the modifications induced by different pretreatments with phosphoric acid or sodium hypochlorite. Carious dentin specimens were obtained from human molars affected by carious lesions. Specimens were divided in four groups and submitted to: (1) untreated; (2) 35% phosphoric acid for 15 s; (3) 35% phosphoric acid for 15 s and 5% sodium hypochlorite for 2 min; (4) sodium hypochlorite for 5 min.

Evidence for redifferentiation of human chondrocytes grown on a hyaluronan-based biomaterial (HYAff 11): molecular, immunohistochemical and ultrastructural analysis.

Association of biomaterials with autologous cells can provide a new generation of implantable devices for cartilage repair. Such scaffolds should provide a preformed three-dimensional shape and prevent cells from escaping into the articular cavity. Furthermore, these constructs should have sufficient mechanical strength to facilitate handling in a clinical setting and stimulate the uniform spreading of cells and their phenotype redifferentiation.

High resolution SEM evaluation of dentin etched with maleic and citric acid.

Objectives: This study evaluated the ultra-morphological effects of maleic and citric acid on human dentin by means of a field emission in-lens scanning electron microscope (FEISEM). Both acids were tested on human dentin at pH 0.7 and 1.