Enamel Microcracks Induced by Simulated Occlusal Wear in Mature, Immature, and Deciduous Teeth (original) (raw)
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BMC Oral Health
Background Dental enamel, the hardest outermost layer of a human tooth, is subjected to occlusal forces throughout life during different oral function as talking, mastication etc. Due to this continuous stress, wear causes the loss of this protective shell. This study aimed to detect microscopic differences in enamel’s wear behavior among different age groups of adolescents and adults. Aims and methods Enamel specimens from immature open-apex and mature closed-apex premolars were subjected to simulated occlusal wear of impact and sliding wear test ISWT. Upper and lower enamel specimens were made to come in contact under controlled conditions. The enamel specimens’ surfaces were examined using different microscopes. The upper and lower specimens were subjected to the following tests; pre-test light microscopy examination, enamel specimens’ preparation for ISWT, scanning laser confocal microscopy of upper specimens, three-dimensional (3D) colored laser microscope and a Profilometer im...
Microhardness of the enamel exposed to whitening dentifrices
Revista de Odontologia da Universidade Cidade de São Paulo, 2017
Introduction: The purpose of this study is to verify the effect of three different types of dentifrices on the superficial microhardness of bovine enamel. Methods: Forty-eight 4x4mm dental fragments were polished and randomly divided into 4 groups: GI, conventional silica-based dentifrice; GII, hydrogen peroxide-based dentifrice; GIII, carbamide peroxide-based dentifrice; and GIV, immersion in artificial saliva. After polished, the specimens received five indentations of 25g static load, for 5 seconds. Subsequently, specimens from groups GI, GII and GIII were immersed in solution containing dentifrice and distilled water, in weight proportion of 1:2, for 15 minutes daily. After this period, fragments were rinsed in tap water and stored in artificial saliva at 37oC. This procedure was repeated for 21 days and then a new analysis of the microhardness was performed. Results and conclusion: The results were submitted to ANOVA and Fisher’s test at 5%. It was concluded that all samples tr...
Enamel microstructure of deciduous teeth: Types of enamel and resistance to abrasion
2013
The study of the histological structure of enamel can be approached in different ways. One of them allows to establish functional morphological studies, ontogenic or phylogenetic adaptations and/or restrictions (Koenigswald, Goin 2000; Goin et al. 2007) by applying a hierarchical system of classification of tooth enamel microstructure in mammals considering the complexity levels proposed by Koenigswald and Clemens . Five levels can be observed: 1) crystallites: this is the simplest level and studies the smallest of these units, the morphology and the packing of crystal patterns in a small area; 2) prisms: this level includes the description of prismatic and non-prismatic enamels considering their morphology and interprismatic substance; 3) enamel types: this level refers to prismatic enamel types; 4) enamel patterns (schmelzmusters): this level refers to the three-dimensional arrangement of the different enamel types in a tooth and has shown to be relatively constant in some mammali...
Caries research, 2015
This study aimed at assessing the susceptibility of different tooth types (molar/premolar), surfaces (buccal/lingual) and enamel depths (100, 200, 400 and 600 µm) to initial erosion measured by surface microhardness loss (ΔSMH) and calcium (Ca) release. Twenty molars and 20 premolars were divided into experimental and control groups, cut into lingual/buccal halves, and ground/polished, removing 100 µm of enamel. The initial surface microhardness (SMH0) was measured on all halves. The experimental group was subjected to 3 consecutive erosive challenges (30 ml/tooth of 1% citric acid, pH 3.6, 25°C, 1 min). After each challenge, ΔSMH and Ca release were measured. The same teeth were consecutively ground to 200, 400 and 600 µm depths, and the experimental group underwent 3 erosive challenges at each depth. No difference was found in SMH0 between experimental and control groups. Multivariate nonparametric ANOVA showed no significant differences between lingual and buccal surfaces in ΔSMH...
The Angle Orthodontist, 2016
Objective: To find a correlation between the severity of enamel microcracks (EMCs) and their increase during debonding and residual adhesive removal (RAR). Materials and Methods: Following their examination with scanning electron microscopy (SEM), 90 extracted human premolars were divided into three groups of 30: group 1, teeth having pronounced EMCs (visible with the naked eye under normal room illumination); group 2, teeth showing weak EMCs (not apparent under normal room illumination but visible by SEM); and group 3, a control group. EMCs have been classified into weak and pronounced, based on their visibility. Metal brackets (MB) and ceramic brackets (CB), 15 of each type, were bonded to all the teeth from groups 1 and 2. Debonding was performed with pliers, followed by RAR. The location, length, and width of the longest EMCs were measured using SEM before and after debonding. Results: The mean overall width (Woverall) was higher for pronounced EMCs before and after debonding...
Physicochemical Properties of Enamel After Microabrasion Technique
Journal of Research in Dentistry, 2014
AIM: This study aimed to evaluate the enamel microhardness, surface roughness, and chemical composition after microabrasion technique, followed by polishing and different immersion times in artificial saliva. MATERIALS AND METHODS: Ninety enamel blocks (25 mm2) from bovine incisors were divided into two groups (G1 and G2), and then subdivided in five subgroups (n = 9) according to their microabrasion treatment and polishing with a diamond paste: 35% phosphoric acid and pumice (H3PO4+Pum) and polishing; just H3PO4+Pum; 6.6% hydrochloric acid and silica (HCl+Sil) and polishing; just HCl+Sil; and control (no treatment). For G1, roughness and microhardness analyses were performed before (L1) and after (L2) microabrasion. After 15 (L3) and 30 (L4) days of immersion in artificial saliva, microhardness analysis was also performed. After (L4) analysis, the specimens were subjected to SEM analysis. G2 was used for the chemical analysis using energy dispersion testing (EDS). The data was subj...