Background: Developmental defects of enamel (DDE) are frequently encountered in primary and permanent teeth, yet their etiology is not completely known. Enamel hypoplasia is considered a predisposing factor for early caries. The objective of this study was the evaluation of several risk factors potentially causing DDE and the possible association between DDE and dental caries. Methods: This study was performed on a group of 213 rural children from Romania. It combined a thorough dental examination for all children, and a questionnaire filled in by their mothers, regarding the evolution of their pregnancy and the child’s health status in the first years of life. Results: There was no statistically significant association between DDE presence and data regarding the evolution of pregnancy, mothers’ health status or children’s conditions during early childhood. There was a significant association between the use of amoxicillin, ibuprofen, and cephalosporin during the period of formation of permanent teeth, and one environmental factor (water source), and the presence of DDE (Chi Square, p < 0.05). Also, DDEs were associated with the presence of caries (Fisher, p = 0.001). Conclusions: Children who consumed water from private wells and children who received medication during early childhood developed more enamel defects, presenting a higher risk of caries development.

Developmental defects of enamel (DDEs) are deviations from the normal appearance in terms of the quantity and quality of tooth enamel. They may be genetic or acquired. The most important DDEs are hypomineralization and hypoplasia. The aim of this study was to produce “in vivo” DDE in Wistar rats by administering amoxicillin to pregnant females and to highlight these lesions after sacrifice of the pups by macroscopic and microscopic examination and optical coherence tomography (OCT). Amoxicillin (100 mg/kg) was administered to two pregnant Wistar female rats for the production of DDEs. When the pups were 2 months old, they were sacrificed, and their jaws were harvested together with their teeth. The jaws were examined macroscopically, microscopically, and by OCT. Following the macroscopic and microscopic examination, it was established that four pups had a total of 42 DDE lesions. At the OCT examination, the hypomineralization was characterized by an intense, inhomogeneous OCT signal, and the hypoplasia was characterized by the absence of the signal. Administration of amoxicillin to pregnant females of Wistar rats resulted in DDEs in their offspring. The OCT examination confirmed the presence of these lesions in the teeth of rat pups.

The development of the finite element method (FEM) combined block polynomial interpolation with the concepts of finite difference formats and the variation principle. Because of this combination, the FEM overcomes the shortcomings of traditional variation methods while maintaining the benefits of current variation methods and the flexibility of the finite difference method. As a result, the FEM is an advancement above the traditional variation methods. The purpose of this study is to experimentally highlight the thermal behavior of two stomatognathic systems, one a control and the other presenting orthodontic treatment by means of a fixed metallic orthodontic appliance, both being subjected to several thermal regimes. In order to sustain this experimental research, we examined the case of a female subject, who was diagnosed with Angle class I malocclusion. The patient underwent a bimaxillary CBCT investigation before initiating the orthodontic treatment. A three-dimensional model with fully closed surfaces was obtained by using the InVesalius and Geomagic programs. Like the tissues examined in the patient, bracket and tube-type elements as well as orthodontic wires can be included to the virtual models. Once it is finished and geometrically accurate, the model is exported to an FEM-using program, such as Ansys Workbench. The intention was to study the behavior of two stomatognathic systems (with and without a fixed metallic orthodontic appliance) subjected to very hot food (70 °C) and very cold food (−18 °C). From the analysis of the obtained data, it was concluded that, following the simulations carried out in the presence of the fixed metallic orthodontic appliance, significantly higher temperatures were generated in the dental pulp.

Several decades after the development of FEM in computer-based form, which is a milestone in the evaluation of mechanical systems, the method has been adopted to analyze the biomechanical response of human skeletal structures. This innovative technique has generated new questions, but also new results, and, at the same time, competitive environments with explosive development, in the recent period. This research is focused on analyzing, using FEM, the extreme thermal variations produced at the level of two oro-facial systems (one control and one subjected to orthodontic therapy using a fixed metallic orthodontic appliance). The objective of the study was to determine the temperature evolution in different dental structures subjected to extreme temperatures given by variations between very cold and very hot foods. Each system was exposed to a succession of extreme thermal regimes (70…−18…70… °C and −18…70…−18… °C). In order to conduct this research, we used the case of a 14-year-old female patient. Following an orthodontic evaluation, we discovered that the patient had dento-alveolar disharmony with crowding. The straight-wire method of applying a fixed metallic orthodontic appliance was chosen. As complementary examinations, the patient was subjected to a bimaxillary CBCT. Using a series of programs (InVesalius, Geomagic, SolidWorks, and AnsysWorkbench), a three-dimensional model was obtained. This model contained jaws and teeth. Also, brackets, tubes, and orthodontic wires can be incorporated into the model. Following the simulations carried out in this study, it was found that thermal variations from the dental pulp are more severe for the oro-facial system with a fixed metallic orthodontic appliance (regardless of the type of thermal stimulus used). Thus, even today, with all the facilities available in the dental materials industry, metallic orthodontic devices present significant thermal conductivity, generating harmful effects on the dental structures. The reading of the results was performed on the virtual model, more precisely, on the internal dental structures (enamel, dentin, and pulp). A statistical study was not performed because it was considered that, in other patients, the results would be similar.

The development of the finite element method (FEM) combined block polynomial interpolation with the concepts of finite difference formats and the variation principle. Because of this combination, FEM overcomes the shortcomings of traditional variation methods while maintaining the benefits of current variation methods and the flexibility of the finite difference method. As a result, FEM is an advancement above the traditional variation methods. The aim of the study is to experimentally determine the thermal behavior of two stomatognathic systems, one control and the other presenting orthodontic treatment by means of a fixed metallic orthodontic appliance, both being subjected to several thermal regimes. In order to carry out this experimental study, we examined the case of a female subject, who was diagnosed with Angle class I malocclusion. The patient underwent a bimaxillary CBCT investigation before initiating the orthodontic treatment. A three-dimensional model with fully closed surfaces was obtained by using the InVesalius and Geomagic programs. Like the tissues examined in the patient, bracket and tube-like components, as well as orthodontic wires, can be included to these models. Once it is finished and geometrically accurate, the model is exported to a FEM-using program, such as Ansys Workbench. The intention was to study the behavior of two stomatognathic systems (with and without a fixed metallic orthodontic appliance) subjected to very hot food (70 ⁰C) and very cold food (-18 ⁰C). From the analysis of the obtained data, it was concluded that, following the simulations carried out in the presence of the fixed metallic orthodontic appliance, significantly higher temperatures were generated in the dental pulp.

Background/Objectives: Although factors acting both prenatally and postnatally are taken into consideration, the etiopathogenesis of developmental defects of enamel (DDE) is not fully understood. Among the medications used for a variety of ailments, amoxicillin and cefaclor are indicated as having a part in the development of DDE. The objective of the present study was to reproduce DDE in the laboratory in rats by administering amoxicillin, ibuprofen, and cefaclor. These lesions were subsequently diagnosed using polarized light microscopy (PLM). Methods: This study was conducted on Wistar rats, which were given prenatally drugs possibly involved in the production of DDE. After macroscopic examination and identification of enamel defects, bright-field microscopy (BFM) and PLM examination were performed. Results: The group that received cefaclor was the most affected, according to the data gathered from this study. This group was followed by the groups that received amoxicillin in a double dose, ibuprofen, amoxicillin in a standard dose, and the control group. Conclusions: In the control group, DDE was identified in a reduced number, resulting in the fact that there are other factors involved, besides the drugs administered, in the development of DDE. Following this research, it was concluded that DDE in the form of demineralization was more frequently recorded in the cefaclor and ibuprofen groups, while DDE in the form of hypoplasia was more frequently recorded in the double-dose and standard-dose amoxicillin groups.