An In Vitro Study on the Effects of Hydrogen Peroxide-Based Bleaching Agents on Enamel: Field Emission Scanning Electron Microscopy (FESEM) With Energy Dispersive Spectroscopy (EDS) Evaluation.

Aim and objective The aim of the present in vitro study is to evaluate the morphological and elemental alterations in enamel following bleaching with hydrogen peroxide-based bleaching agents of different concentrations and pH values when exposed to different treatment times. Materials and method Twenty extracted maxillary central incisors were selected for the study. Tooth samples were prepared by sectioning the tooth cervico-incisally into two halves. The teeth were divided into different groups based on the bleaching protocol and bleaching agent applied: Group IA, Group IB, Group IIA, and Group IIB. Group IA received a 35% hydrogen peroxide-based bleaching agent of pH 6 for 10 minutes with light application. Group IB received a 35% hydrogen peroxide-based bleaching agent of pH 6 for 30 minutes with light activation. Group IIA received a 40% hydrogen peroxide-based bleaching agent of pH 8.5 for 10 minutes with chemical activation. Group IIB received a 40% hydrogen peroxide-based bleaching agent of pH 8.5 for 30 minutes with chemical activation. The morphology of the enamel before and after the application of the bleaching agent was evaluated using field emission scanning electron microscopy. The elemental analysis of enamel between the control and test samples was done with the help of energy dispersive spectroscopy. Results Paired t-test was used to analyze the data obtained from the study. The test samples showed erosive alterations in enamel surface morphology and also a decrease in the concentration of minerals when compared to the corresponding control groups. Conclusions The present study evidences the erosive potential of hydrogen peroxide-based bleaching agents. It can be concluded that bleaching agents containing high concentrations of hydrogen peroxide with acidic pH can cause mineral loss and surface erosion of enamel which is extremely detrimental to the tooth integrity.

Novel management of internal root resorption with vertical root fracture using mineral trioxide aggregate - A case report.

Introduction: This case report presents the diagnosis and management of extensive internal root resorption (IRR) in a 17-year-old male patient, with a 9-year-old history of trauma. Method: The affected tooth 21 was associated with vertical root fracture (VRF) and incomplete apex closure with a substantial loss of tooth structure, including dentin and cementum. Encouraged by a healthy periodontal condition, the choice was made to use mineral trioxide aggregate (MTA) to reconstruct and reinforce the resorptive defect and the fractured segment. A composite veneer was placed to enhance the aesthetics. Result: A follow-up of the patient after 2 years revealed healing with a resolution of the lesion. Conclusion: This case report highlights the use of MTA as a lone-standing filling material for the treatment of IRR with VRF in a non-vital immature tooth.