Changes In Dental Enamel Research Articles

Resin infiltrant as a treatment of common changes in dental enamel: narrative literature review

Minimally invasive dentistry has been considered the most suitable method of choice in order to prevent and treat changes in the tooth surface, such as the initial caries lesions, characterized as white spot. This type of conduction aims to maintain the tooth structure, as long as there is no sign of cavitation on the surface. Thus, in 2009 a material was created based on monomers and additives denominated resinous infiltrant, which has the function of paralyzing this white spot lesion acting through diffusion, where the material fills the microporosities. The only material commercially available is Icon®, which, despite having numerous benefits, has some limitations. Some studies with experimental material have been developed in order to try to minimize the limitations of commercial material. Therefore, this literature review aims to address the characteristics, function, application and indications of the material, as well as its limitations.

Surface and Structural Studies of Age-Related Changes in Dental Enamel: An Animal Model.

In the animal kingdom, continuously erupting incisors provided an attractive model for studying the enamel matrix and mineral composition of teeth during development. Enamel, the hardest mineral tissue in the vertebrates, is a tissue sensitive to external conditions, reflecting various disturbances in its structure. The developing dental enamel was monitored in a series of incisor samples extending the first four weeks of postnatal life in the spiny mouse. The age-dependent changes in enamel surface morphology in the micrometre and nanometre-scale and a qualitative assessment of its mechanical features were examined by applying scanning electron microscopy (SEM) and atomic force microscopy (AFM). At the same time, structural studies using XRD and vibrational spectroscopy made it possible to assess crystallinity and carbonate content in enamel mineral composition. Finally, a model for predicting the maturation based on chemical composition and structural factors was constructed using artificial neural networks (ANNs). The research presented here can extend the existing knowledge by proposing a pattern of enamel development that could be used as a comparative material in environmental, nutritional, and pharmaceutical research.

ASSESSMENT OF DENTAL CARIOUS LESIONS BY ICDAS II

Introduction. The largest amount of information about the dental caries is provided by the International Caries Detection and Assessment II system (ICDAS II), which is known as evidence-based approach to clinical visual detection of dental caries and enables to detect the stage and depth of carious lesions from the slightest changes in dental enamel to visible cavities affecting dentin. This system has been developed by the group of leading experts in the field of cariology. The results obtained by determining the ICDAS II index contribute to making right clinical decision in the choice of prevention and treatment methods, as well as to predicting the carious progression. The aim of the study is to assess the prevalence and intensity of initial dental caries in people using the ICDAS II index. Materials and methods. A total of 32 patients aged 12 to 25 years were examined. During the dental examination, we assessed the prevalence of dental caries using the ICDAS II. Clinical findings were recorded in oral follow-up charts proposed by the ICDAS Foundation for Epidemiological Studies, which allow us to record dental hard tissue status using six codes: three for assessing carious changes in enamel and three for assessing carious changes in dentine in a sequence of growing severity. Statistical processing of the findings was performed using Student's t-test. Results. Carious lesions were detected in all study participants, their total number was 285, of which 140 (49.1%) had the code 1 and 145 (50.8%) had the code 2 according to the ICDAS II. On average, each of the participants had 9.28 ± 0.67 foci of enamel demineralization. The average number of lesions with codes 1 and 2 by the ICDAS II was respectively 4.54 ± 0.51 and 4.74 ± 0.38 (p> 0.05). The average intensity of dental caries increased with age from 8.29 ± 0.83 in 12-15 year old individuals to 9.39 ± 1.20 in 18-25 year old individuals (p> 0.05), mainly by the growth of the average number of the mean number of caries lesions with the code 1 according to the ICDAS II. Mostly carious lesions are found on the masticatory surfaces, their total number made up 159 (55.7%). 101 (35.4%) caries lesions were found on the vestibular and oral parts of the tooth surfaces, and 25 (8.9%) average lesions were detected on the proximal surfaces. The average intensity of caries detected on the chewing surfaces of the teeth was 5.15 ± 0.49 and was significantly higher than on the vestibular and oral (3.33 ± 0.57, p <0.05) and proximal (0.79 ± 0, 20, p <0.001) surfaces. Conclusion. The obtained results showed a high intensity of carious lesions, with their predominance in the active stages in the two age groups under the study. This proves the appropriateness of using diagnostic ICDAS criteria for early detection of initial caries and its proper treatment.

Amelogenesis Imperfecta Enamel Changes, Amelogenin, and Dental Caries Susceptibility

There is great interest in identifying the subset of individuals in the population that are more susceptible to dental caries. We proposed that a portion of these particular individuals are more susceptible to dental caries due to changes in dental enamel that are related to amelogenin genomic variation. However, apparently amelogenin function can be impacted by inflammation, and this can lead to small changes in the structure of the dental enamel that later in life increases the risk of dental caries.

Aesthetic perceptions and social judgments about different enamel opacities.

This study aimed to evaluate adolescents' aesthetic perceptions and their social judgments regarding different enamel opacities. Sample size was calculated and resulted in the inclusion of 100 adolescents (aged 10 to 15 years) from a public school in Jequié, Bahia, Brazil. Images of enamel opacities were manipulated to create aesthetic enamel defects, such as enamel color changes (unilateral and bilateral white opacity, unilateral and bilateral yellowish opacity, and unilateral and bilateral yellowish opacity with loss of structure). The images of the opacities were based on Fédération Dentaire Internationale's Developmental Defects of Enamel (DDE) Index. Aesthetic perception and social judgments were evaluated using a validated questionnaire with 12 questions (six positive and six negative points) on social aspects, considering the six manipulated images and the control. The photographic analyses were projected one-by-one by computer to adolescents individually in a classroom. Participants had one minute to observe each image and answer the questionnaire. The data were analyzed by descriptions, and the Friedman Wilcoxon test (p < 0.05). The results indicate that all opacities negatively impacted social judgment (p < 0.001). The enamel aesthetic defects most affecting an individual's perception were bilateral yellow opacity with or without loss of structure (p < 0.001). Regarding social judgment, all participants showed a negative perception of all the tested opacity types (p < 0.001). In conclusion, even opacities presenting only a color change caused aesthetic dissatisfaction to the individuals and changes in their social judgment toward others. Color changes in dental enamel have several aesthetic consequences.

Evaluation of the Erosive Potential of Selected Isotonic Drinks: In Vitro Studies.

Isotonic drinks are an important component of the diet of athletes. Sports drinks cause the body to maintain proper hydration and supplement minerals which are lost in sweat during excessive exercising. Aside from the benefits of isotonic drinks, it is important to be aware of the harmful effects of citric acid within the products, which could cause enamel erosion. The aim of the study was to evaluate the erosive potential of sports drinks using confocal scanning laser microscopy (CLSM). The studies measured the change of surface roughness of the dental enamel after etching using Isostar, Powerade and Gatorade drinks, and Fortuna orange juice. Measurements were repeated after 1, 2 and 3 h of exposure to the selected liquid. The evaluation of calcium compound contents was carried out using the complexonometric method. The surface roughness measurements of dental enamel showed that the lowest values of the parameters Ra and Rz were obtained for Isostar and orange juice. The research of the calcium content in the selected beverages showed the highest value in Isostar (320.0 mg/L) and the lowest in Powerade (40.0 mg/L) and Gatorade (21.0 mg/L). Our study confirms that Isostar is the safest sports drink, among the analyzed beverages, for athletes, because it causes the least erosive changes in dental enamel. It is recommended to supplement beverages to reduce their potential for erosion using calcium compounds.

Non-invasive in vivo visualization of enamel defects by reflectance confocal microscopy (RCM)

The enamel defects (EDs) may present with a variety of clinical manifestations with increasing severity from the sole appearance of pale discoloration to remarkable structural alterations. EDs are responsible for higher caries receptivity. In vivo reflectance confocal microscopy (RCM) allows to image in vivo at microscopic resolution of the dental surface, thus avoiding the tooth extraction and the sample preparation because of its ability to optically scan living tissues along their depth. Aim of this study is the in vivo assessment at microscopic resolution of dental surfaces affected by EDs without resorting to invasive methods such as teeth extractions, to define histological findings occurring in chromatic and/or structural EDs. For the purpose, 15 children, referring at the Dental Clinic of the Second University of Naples, affected by several degrees of EDs, were enrolled and underwent in vivo RCM imaging to microscopically define the ED confocal features using a commercially available hand-held reflectance confocal microscope with neither injuries nor discomfort. Totally, 29 teeth were imaged. Results demonstrated images good in quality and the capability to detect EDs such as unevenness, grooves, and lack of mineralization according to their clinical degree of disarray. The present in vivo microscopic study on EDs allowed to highlight structural changes in dental enamel at microscopic resolution in real-time and in a non-invasive way, with no need for extraction or processing the samples. Further experiments could define the responsiveness to remineralizing procedures as therapeutic treatments.

Mineral Loss and Morphological Changes in Dental Enamel Induced by a 16% Carbamide Peroxide Bleaching Gel

The aim of this study was to compare the effect of a 16% carbamide peroxide (CP) gel and a 10% CP gel on mineralized enamel content and morphology. Enamel blocks from bovine incisors were subjected to a 14-day treatment (8 h/day) with 10% or 16% CP gels. Knoop microhardness was evaluated before bleaching and at 1, 7 or 14 days after this treatment (50 g/15 s). Mineral content (energy-dispersive x-ray spectroscopy), surface roughness and topography (atomic force microscopy) were evaluated at the 14-day period. Data were analyzed statistically by two-way ANOVA and Tukey's test (α=0.05). Significant microhardness reduction was observed at the 7 th and 14 th days for 10% CP gel, and for all bleaching times for 16% CP gel (p<0.05). At the 14-day period, a significant decrease in Ca and P content, increase on surface roughness (p<0.05) as well as on picks and valleys distance were observed when both bleaching gels were used. These enamel alterations were more intense for 16% CP gel. It was concluded that both CP-based gels promoted loss of mineral structure from enamel, resulting in a rough and porous surface. However, 16% CP gel caused the most intense adverse effects on enamel.

Capability of an Ultrasonic System to Detect Very Early Caries Lesions on Human Enamel

The purpose of this investigation was to determine if changes in dental enamel with 20 micron depth incipient carious lesion could be detected by an ultrasonic system (US). Natural (unground, unpolished) lesions were produced on human enamel by using a microbial caries model. Specimens with lesions were analyzed using Ultrasonic system (US) as test method, Quantitative-Light Induced Fluorescence (QLF) and Confocal Laser Scanning Microscopy (CLSM) as gold standards. It was found that both ultrasound and QLF could not detect these very early lesions (mean lesion depth: 18.89 µm) created in vitro in the microbial caries model.

Tooth Enamel Evaluation After Tooth Bleaching With Hydrogen Peroxide Assisted by a DC Nonthermal Atmospheric-Pressure Plasma Jet

The purpose of this study is to evaluate the changes in dental enamel (morphology, elemental composition, microhardness, and roughness) after applying hydrogen peroxide in conjunction with a nonthermal plasma to bleach the teeth. Extracted human teeth were randomly placed in six groups. Two control groups (one group with no bleaching agent and no plasma treatment of the teeth and another one with only hydrogen peroxide as the bleaching agent) and four plasma groups (receiving hydrogen peroxide of varying concentrations 6%, 15%, 25%, and 35%, in conjunction with a plasma treatment) were prepared. The surface morphology before and after treatment was assessed using a scanning electron microscope (SEM), and the change in the elemental composition was analyzed by an energy-dispersive X-ray spectroscopy system. A total of 36 extracted teeth were used to evaluate the change in enamel microhardness and surface roughness. The use of hydrogen peroxide as a bleaching agent, even in the absence of plasma exposure, causes various etching patterns that are attributable to demineralization during the treatment process. These patterns are more pronounced as the hydrogen peroxide concentration increases. The surface roughness tests confirmed the findings from the SEM analysis. We only found minor essentially insignificant changes in the elemental composition of the enamel and in the surface microhardness as a result of the treatment using hydrogen peroxide and a cold plasma. The use of a cold plasma in conjunction with hydrogen peroxide of varying concentrations in tooth bleaching causes minor changes in the tooth enamel changes that are comparable to those resulting from the standard treatment using 35 % hydrogen peroxide gel without a plasma.

Changes in dental enamel oven heated or irradiated with Er,Cr:YSGG laser. Analysis by FTIR

This study evaluated the change that occurs in dental enamel under action of oven heating or Er,Cr:YSGG laser irradiation aiming to obtain a structure more resistant to demineralization. Enamel powder was obtained from bovine teeth. Samples were subjected to oven heating at temperatures of 200, 400, 600, 800, and 1000°C or during laser irradiation with energy densities of 7.53, 10.95, and 13.74 J/cm2. The infrared thermography was used to measure the surface temperature generated in the solid samples of enamel during lasers irradiation. The samples were analyzed by Fourier transform infrared spectroscopy (FTIR), which shows changes on enamel oven heated or laser irradiated, due to treatments, related to carbonates, adsorbed water and hydroxyl content. These compositional effects were more evident in lased samples. These changes may alter the material properties such as its solubility, and decrese of demineralization that is important for caries prevention.

Reconstructing impairment of secretory ameloblast function in porcine teeth by analysis of morphological alterations in dental enamel.

We studied the relationship between the macroscopic appearance of hypoplastic defects in the dental enamel of wild boar and domestic pigs, and microstructural enamel changes, at both the light and the scanning electron microscopic levels. Deviations from normal enamel microstructure were used to reconstruct the functional and related morphological changes of the secretory ameloblasts caused by the action of stress factors during amelogenesis. The deduced reaction pattern of the secretory ameloblasts can be grouped in a sequence of increasingly severe impairments of cell function. The reactions ranged from a slight enhancement of the periodicity of enamel matrix secretion, over a temporary reduction in the amount of secreted enamel matrix, with reduction of the distal portion of the Tomes' process, to either a temporary or a definite cessation of matrix formation. The results demonstrate that analysis of structural changes in dental enamel allows a detailed reconstruction of the reaction of secretory ameloblasts to stress events, enabling an assessment of duration and intensity of these events. Analysing the deviations from normal enamel microstructure provides a deeper insight into the cellular changes underlying the formation of hypoplastic enamel defects than can be achieved by mere inspection of tooth surface characteristics alone.

A quantitative backscattered electron imaging study of hypomineralization and hypoplasia in fluorosed dental enamel of deer

Mineral content and distribution of fluorosed and unfluorosed (control) dental enamel of roe deer and red deer cheek teeth were analyzed using digital backscattered electron (BSE) imaging of PMMA-embedded specimens. Compared to the controls, the fluorosed enamel exhibited various aberrations resulting from a fluoride-induced disturbance of the processes involved in enamel formation. Thus, the presence of surface hypoplasias and an enhancement of the incremental pattern in the fluorosed enamel are evidence of a fluoride impact on the secretory ameloblasts, whereas a (subsurface) hypomineralization of different depth and extent is indicative of a fluoride effect on the maturation stage of amelogenesis. The marked variation in the severity of enamel hypomineralization seen along the coronocervical axis of a specimen pointed to a fluoride impact of varying intensity during this period of tooth development. Our observations further indicated that, in some locations, ameloblasts severely affected by fluoride during enamel matrix formation were able to recover from this insult and to function quite normally during the maturation stage of amelogenesis. A major advantage of the BSE imaging technique used in the present study over other methods is that it allows for a combination of micromorphological information with quantitative data on the mineralization of the analyzed tissue, which proved to be very useful for the characterization of fluoride-induced changes in dental enamel.

Surface changes in dental enamel and dentin resulting from laser irradiation

Surface changes in dental enamel and dentin resulting from laser irradiation

Structural changes in dental enamel induced by high energy continuous wave carbon dioxide laser

The morphological changes in dental enamel exposed to a high energy continuous beam surgical carbon dioxide laser were studied with a wet-scanning electron microscope. Utilizing a 1 mm focused beam, energy levels of 5, 10, and 12.5 watts were applied to the external enamel surface of teeth for between 0.05 and 2 seconds. Subsequent examination showed melting and resolidification of the surface enamel. Examination in cross section revealed three different zones of change, which were consistent in thickness. The outer layer of melted and resolidified enamel approximates 100 microns in width, whereas the next zone of acid resistant amorphous enamel measures only 12 microns in width and the third zone of porous enamel measures approximately 110 microns in width. Though of no immediate practical value in dentistry, the exact physical chemical changes occurring in the enamel warrant further investigation.

Quantitative Microradiography for Studying Dental Enamel Demineralization and Remineralization

A method for quantitative determination of mineral density changes in dental enamel has been developed. It utilizes the quantitative microscopy capabilities of image analysis or photometer systems. Characteristic demineralization of bovine enamel in acetate buffers containing calcium and phosphate has been used to demonstrate the results. The method together with chemical kinetic data obtained from spectrophotometric and ion-selective electrode measurements of the bulk solution for calcium, phosphate, and fluoride permit important basic studies to be conducted on demineralization and remineralization of dental enamel.

Posteruptive Changes in Dental Enamel

Posteruptive Changes in Dental Enamel