Qualitative Histological Evaluation of Hard and Soft Tissue Components of Human Permanent Teeth Using Various Decalcifying Agents - A Comparative Study

Introduction: Decalcification is the commonly employed technique in histopathology laboratories as a part of calcified tissue preparation for the microscopic examination. Chemical agents are most commonly used for routine decalcification procedures, though some agents adversely affect the tissue integrity and staining properties. Aim: To compare the efficacy of various decalcifying agents by histological evaluation of hard and soft tissue components of teeth. Materials and Methods: The five decalcifying agents namely 10% Nitric acid (HNO3), 10% Formal nitric acid (FNA), 10 % Formic acid (FA), 8% Potassium formate (KF) + 8% Formic acid (FA) and Neutral Ethylenediamenetetracetic acid (EDTA) were used to decalcify 60 human permanent teeth. The specimens were subjected to routine processing, sectioning and staining with hematoxylin and eosin. The stained sections were observed under light microscope by three independent observers and grading was done. Statistical Analysis: Paired sample t-test was done for inter-observer variation. One-way-ANOVA and Post-hoc test was applied to compare the effects of different decalcifying agents. Results: Considering preservation and staining characteristics of both hard and soft tissues, superior results were obtained with 10% HNO3 followed by 10% FNA and EDTA which was according to the respective mean values obtained. But statistically significant difference was shown only with 10% FA & 8% KF + 8% FA. Conclusion: HNO3 was showing the most efficient result as it balances both tissue integrity and time factor suggesting that it can be used as a stable decalcifying agent for routine histopathological diagnosis.