To determine the effects of Er:YAG laser irradiation on the surface nanomorphology of human dental enamel.Materials and methods: five samples of human dental enamel were divided into five groups: (a) I and II were irradiated with Er:YAG & water irrigation (12.7 J cm −2 and 25.5 J cm −2 , respectively); (b) III and IV were Er:YAG laser irradiated & no water irrigation (12.7 J cm −2 and 25.5 J cm −2 , respectively); (c) V or control (no laser irradiation). Nanomorphological changes were observed on 1 μm × 1 μm areas by AFM (contact mode and air). The partition functions and multifractal spectra were calculated.The graphical results showed that the larger the spectrum width Δα (Δα = α max − α min ) of the multifractal spectra f(α) the more non-uniform the surface nanomorphology. One way analysis of variance (ANOVA) was performed (P < 0.05) to distinguish significant differences between the groups.All the investigated surfaces exhibited multifractal behavior. The computational algorithm indicated that the multifractal spectra differ significantly from each other for the different groups. AFM (atomic force microscopy), the statistical surface roughness parameters, and multifractal analysis provided useful information about the surface nanomorphology and optimal surface characteristics. This approach could be extended to other enamel surfaces in order to characterize its structural 3D microrelief.

This work aims to contribute to the knowledge of human cementum protein 1 (CEMP1), its conformational characteristics and influence during the biomineralization process. The results revealed that hrCEMP1 expressed in Pichia pastoris is a 2.4% glycosylated, thermostable protein which possesses a molecular mass of 28 770 Da. The circular dichroism spectrum indicated a secondary structure content of 28.6% of alpha-helix, 9.9% of beta-sheet and 61.5% of random-coil forms. Biological activity assays demonstrated that hrCEMP1 nucleates and regulates hydroxyapatite crystal growth. Hereby, it is demonstrated for the first time that CEMP1 has a (C-type) lectin-like activity and specifically recognizes mannopyranoside. The information produced by this biochemical and structural characterization may contribute to understand more fully the biological functions of CEMP1.

The ectopic calcifications of non-mineralized tissues can occur in several forms throughout life, such as pulpal calcification. The presence of pulp stones is a challenge in endodontic treatment because they partially or fully obliterate the pulp chamber hindering access to root canals and their subsequent shaping. This study aimed to determine their crystallographic properties and evaluate the capacity of citric acid (CA) and ethylenediaminetetraacetic acid (EDTA) to promote the demineralization of pulp calcifications. The samples were obtained from patients with indications of endodontic treatment, and the radiographic examination was suggestive of pulp stone in at least one permanent tooth. The samples were isolated and analyzed by scanning electron microscopy/energy-dispersive x-ray spectroscopy (SEM/EDX). The Fourier Transform by high resolution-transmission electron microscopy, Raman microscopy, and X-ray diffraction (XRD) were used to identify the mineral phase and crystallo-

No abstract