MDPI Open Access Journals zoom_out_map search menu Journals Dentistry Journal Volume 13 Issue 4 10.3390/dj13040168 Download PDFsettingsOrder Article Reprints Open AccessArticle Calcium and Microhardness Quantification in Healthy and Fluorotic Dentin Conditioned with a Self-Etching System: An In Vitro Study by José Alejandro Rivera Gonzaga 1,Ana Josefina Monjarás Ávila 1ORCID,Louis Hardan 2,3ORCID,Norma Verónica Zavala Alonso 4ORCID,Carlos Enrique Cuevas Suárez 1ORCID,Nicolas Nassar 3,5,6ORCID,Ahmed A. Holiel 7,8ORCID,Naji Kharouf 9,10ORCID,Youssef Haikel 9,10,11ORCID andRim Bourgi 2,8,9,*ORCID 1 Dental Materials Laboratory, Academic Area of Dentistry, Autonomous University of Hidalgo State, San Agustín Tlaxiaca 42160, Mexico 2 Department of Restorative Dentistry, School of Dentistry, Saint-Joseph University, Beirut 1107 2180, Lebanon 3 Department of Digital Dentistry, AI, and Evolving Technologies, Faculty of Dental Medicine, Saint Joseph University, Beirut 1107 2180, Lebanon 4 Faculty of Dentistry, Autonomous University of San Luis Potosí, San Luis Potosí 78000, Mexico 5 Department of Orthodontics, Faculty of Dental Medicine, Saint Joseph University, Beirut 1107 2180, Lebanon 6 Craniofacial Research Laboratory, Faculty of Dental Medicine, Saint Joseph University of Beirut, Beirut 1107 2180, Lebanon 7 Conservative Dentistry Department, Faculty of Dentistry, Alexandria University, Alexandria 21532, Egypt 8 Department of Restorative Sciences, Faculty of Dentistry, Beirut Arab University, Beirut 115020, Lebanon 9 Department of Biomaterials and Bioengineering, INSERM UMR_S 1121, University of Strasbourg, 67000 Strasbourg, France 10 Department of Endodontics and Conservative Dentistry, Faculty of Dental Medicine, University of Strasbourg, 67000 Strasbourg, France add Show full affiliation list * Author to whom correspondence should be addressed. Dent. J. 2025, 13(4), 168; https://doi.org/10.3390/dj13040168 Submission received: 25 February 2025 / Revised: 31 March 2025 / Accepted: 14 April 2025 / Published: 17 April 2025 (This article belongs to the Special Issue Restorative Dentistry: Emerging Trends and Personalized Treatment Strategies for Optimal Patient Care) Downloadkeyboard_arrow_down Browse Figures Versions Notes Abstract Background: Dental fluorosis can affect the micromorphology of dentin, a fact that could present constraints relating to the structural, mechanical, and chemical stability of dentin when it is demineralized in operative maneuvers. Introduction: The aim of this article is to quantify the amount of calcium and the microhardness of both a healthy and a fluorotic dentin through conditioning with a two-step self-etching system (Optibond Versa, Kerr, CA, USA). Methods: Dentin samples were obtained from healthy molars diagnosed with mild, moderate, and severe fluorosis. The amount of calcium was quantified utilizing an atomic absorption spectrophotometer. The hardness was evaluated using a Vickers durometer. Two dentin samples from each study group were examined using scanning electron microscopy (SEM). Results: A one-way analysis of variance (ANOVA) and Tukey–Kramer test were applied as post hoc tests for determining the differences in calcium values between the study groups and to show the difference in the hardnesses evaluated. The Student’s t-test was applied to related samples. The level of significance was set at p < 0.05. Statistically significant results were obtained for the amount of calcium and microhardness of the healthy dentin group. The SEM images demonstrated irregular etching patterns in the fluorotic dentin, indicating potential bonding challenges. Conclusion: In conclusion, there is a lower amount of calcium and a significant reduction in microhardness in healthy dentin when applying the self-etching system compared to fluorotic dentin. Fluorotic dentin is more resistant to demineralization, which may influence adhesive bonding strategies. Clinicians should consider adjusting conditioning protocols for optimal adhesion in fluorotic teeth. Keywords: calcium; dentin; fluorosis; microhardness; self-etch system