Antioxidants and biomarkers of oxidative damage in the saliva of patients with Down's syndrome.

Background: The aim of this study was to investigate enzymatic and non-enzymatic antioxidant systems and levels of biomarker levels of oxidative damage in the saliva of patients with Down's syndrome (DS).

Methods: Saliva samples were collected from 30 patients with DS and control group (age: 14-24 years). Subsequently, the concentrations of superoxide dismutase, concentration of malondialdehyde, carbonylated proteins, uric acid, vitamin C and total protein, peroxidase activity and total antioxidant capacity were analyzed.

Dentine microhardness after different methods for detection and removal of carious dentine tissue.

Unlabelled: There are several methods for identifying carious dentinal tissue aiming to avoid removal of healthy dentinal tissue.

Objectives: The purpose of this study was to test different methods for the detection of carious dentinal tissue regarding the amount of carious tissue removed and the remaining dentin microhardness after caries removal.

Material And Methods: The dentin surfaces of 20 bovine teeth were exposed and half of the surface was protected with nail polish.

Dimensional alterations and solubility of new endodontic sealers.

This study evaluated the dimensional alterations and the solubility of two experimental endodontic sealers based on Copaifera multijuga oil-resin (Biosealer) and castor oil bean cement (Poliquil), maintained in different storage solutions. Twenty specimens (3 mm diameter and 2 mm height) of each sealer were assigned to 2 groups (n=10) according to the storage solution: simulated tissue fluid (STF) or distilled water (DW). The specimens were stored in these solutions during 90 days, being removed every 30 days for weighting.

Peroxide penetration from the pulp chamber to the external root surface after internal bleaching.

Purpose: To quantify the amount of peroxide penetration from the pulp chamber to the external surface of teeth during the walking bleaching technique.

Methods: Seventy-two bovine lateral incisors were randomly divided over five experimental groups and one control (n = 12 per group): (1) 35% hydrogen peroxide (HP); (2) 35% carbamide peroxide (CP); (3) sodium perborate (SP); (4) (HP+SP); (5) (CP+SP) and (6) Control (CG), deionized water. All groups were treated according to the walking bleach technique.

Transdentinal protective role of sodium ascorbate against the cytopathic effects of H2O2 released from bleaching agents.

Objectives: The objectives of this study were to evaluate the transdentinal cytotoxicity of 10% and 16% carbamide peroxide gel (CP), as well as the ability of the antioxidant, 10% sodium ascorbate (SA), to protect the odontoblasts in culture.

Study Design: Human dentin discs of 0.5-mm thickness were obtained and were placed into artificial pulp chambers.

Cytotoxic effects of different concentrations of a carbamide peroxide bleaching gel on odontoblast-like cells MDPC-23.

This study evaluated the cytotoxic effects of a carbamide peroxide (CP) bleaching gel at different concentrations on odontoblast-like cells. Immortalized cells of the MDPC-23 cell line (30,000 cells/cm(2)) were incubated for 48 h. The bleaching gel was diluted in DMEM culture medium originating extracts with different CP concentrations.

Smear layer removal by auxiliary chemical substances in biomechanical preparation: a scanning electron microscope study.

The aim of this study was to assess, by scanning electron microscopy analysis, the cleaning ability of irrigants and auxiliary chemical substances in biomechanical preparation. Thirty-two single-rooted human teeth were subjected to standardized root canal instrumentation with different irrigants (n = 8): group 1, 2.5% NaOCl + 17% ethylenediaminetetraacetic acid (EDTA); group 2, 2% chlorhexidine gel + 17% EDTA; group 3, Canal Plus + 2.

The effect of endodontic materials on the optical density of dyes used in marginal leakage studies.

The aim of this study was to determine the effect of the exposure of different endodontic materials to different dye solutions by evaluating the optical density of the dye solutions. Seventy-five plastic tubes were filled with one of the following materials: AH Plus, Sealapex, Portland cement, MTA (Angelus and Pro Root) and fifteen control plastic tubes were not. Each specimen of material and control was immersed in a container with 1 ml of each dye solution.

Penetration of 38% hydrogen peroxide into the pulp chamber in bovine and human teeth submitted to office bleach technique.

This study evaluated the pulp chamber penetration of peroxide bleaching agent in human and bovine teeth after office bleach technique. All the teeth were sectioned 3 mm apical of the cement-enamel junction and were divided into 2 groups, A (70 third human molars) and B (70 bovine lateral incisors), that were subdivided into A1 and B1 restored by using composite resin, A2 and B2 by using glass ionomer cement, and A3 and B3 by using resin-modified glass ionomer cement; A4, A5, B4, and B5 were not restored. Acetate buffer was placed in the pulp chamber, and the bleaching agent was applied for 40 minutes as follows: A1-A4 and B1-B4, 38% hydrogen peroxide exposure and A5 and B5, immersion into distilled water.

Vehicle influence on calcium hydroxide pastes diffusion in human and bovine teeth.

The purpose of this study was to compare the pH and calcium ion liberation after use of calcium hydroxide pastes with different paste vehicles in human or bovine teeth. Ninety-two single-rooted human and bovine roots were used. The roots were instrumented and an external cavity preparation was performed.

In vitro evaluation of apical sealing in root apex treated with demineralization agents and retrofiled with mineral trioxide aggregate through marginal dye leakage.

The purpose of this study was to evaluate the apical seal in root apex treated with different demineralization agents and retrofilled with mineral trioxide aggregate (MTA) using marginal dye leakage. Fifty-six, human single-rooted teeth were instrumented, filled, resected and had retrofilling cavities prepared with ultrasonic tips. Demineralizing agents were applied before the apical cavities were retrofilled with Pro Root MTA.