Vertical root fractures and cracked teeth: post-endodontic root dentinal status through micro-CT assessment after ex vivo fiber post removal.

Objectives: This study aimed to investigate cracked teeth and vertical root fracture observable on micro-CT images of extracted roots of mandibular incisors, after fiber post removal.

Materials And Methods: Thirty mandibular incisors were selected with any degree of slight incisal wear inspected with the aid of a stereomicroscope under 12x magnification, in order to have a group of young adult specimens according to the criteria of Hugoson et al. A sample of twelve mandibular incisors were selected, aged between 20 and 30 years old, with similar dentine volume and thickness.

Influence of a gray background and the illuminant on tooth shade selection.

Statement Of Problem: Visual shade selection in dentistry may be influenced by factors that include the background color and the illuminant.

Purpose: The purpose of this clinical study was to evaluate the influence of using a gray background and a light-correcting device on visual shade selection.

Material And Methods: Two experienced clinicians assessed the incisor color of 30 volunteers using the VITA 3D-MASTER shade guide.

Cytotoxicity Evaluation of Two Bis-Acryl Composite Resins Using Human Gingival Fibroblasts.

Bis-acryl resins are used for temporary dental restorations and have shown advantages over other materials. The aim of this work was to evaluate the in vitro cytotoxicity of two bis-acryl composite resins (Protemp 4 and Luxatemp Star), obtained at 1, 7 and 40 days after mixing the resin components, using a standardized assay employing human primary cells closely related to oral tissues. Human gingival fibroblast cell cultures were exposed for 24 h to either bis-acryl composite resins, polystyrene beads (negative control) and latex (positive control) extracts obtained after incubation by the different periods, at 37 °C under 5% CO2.

In vitro Analysis of Cytotoxicity of Temporary Resilient Relining Materials.

Aims: The aim of this study is to evaluate the in vitro response of human gingival fibroblasts in primary cultures to two materials for temporary relining of dentures: Temporary Soft (TDV, Brazil) and Trusoft (Bosworth, USA) for 24 hours, 7 and 30 days by using a multi-parametric analysis.

Materials And Methods: Each material sample (TDV, TS, Polystyrene, Latex) was prepared and incubated in a culture medium for 1, 7, and 30 days at 37°C. Human gingival fibroblasts were exposed to the extracts and cell viability was evaluated by a multi-parametric assay, which allowed sequential analysis of mitochondrial activity (XTT), membrane integrity [neutral red (NR)], and cell density [crystal violet dye exclusion (CVDE)] in the same cells.

Effect of Citric Acid and Ethylenediaminetetraacetic Acid on the Surface Morphology of Young and Old Root Dentin.

Introduction: The aim of this in vitro study was to evaluate the effect of 10% citric acid and 17% ethylenediaminetetraacetic acid (EDTA) irrigating solutions on the surface morphology of young and old root dentin by determining the number and diameter of dentinal tubules using scanning electron microscopy (SEM).

Methods And Materials: Fifty healthy human teeth collected from young (≤30 years) and old (≥60 years) individuals (n=25) were first prepared with a Largo bur #2 to produce smear layer on the root canal surface. Subsequently, the crowns and the root middle and apical thirds were sectioned and removed, and the cervical thirds were sectioned vertically in the buccal-lingual direction into two equal halves.