Novel Approach to Tissue Fixation: Clove Oil versus Local Anaesthetic Solution and Formalin

Introduction: Proper fixation and preservation of tissue are important in rendering an accurate histopathological diagnosis. Fixation with 4% formaldehyde or 10% neutral-buffered formalin has been practiced since many years. Despite its advantages, the safety risks associated with formalin remain a significant concern for its routine use in laboratories. Also, availability of formalin for tissue preservation is frequently lacking during medical camps, necessitating accessible alternatives. Various studies have explored the use of local anaesthetic solution (LA) as a tissue fixative. While LA has shown promising results, the outcomes have varied amongst the majority of studies. Moreover, clove oil which is readily available in dental clinics has gained significant attention for its attributes, including anti-inflammatory, analgesic, anaesthetic, phenolic content, dehydration ability and antimicrobial properties, suggesting its potential use as a fixative. Hence, this study was undertaken with an innovative fixation approach, aiming to explore fixative property of clove oil and compare it with LA and 10% neutral-buffered formalin.
Objective: To compare the efficacy of clove oil with LA and 10% neutral buffered formalin as tissue fixative.
Methodology: In this study, fresh chicken samples were fixed using three different solutions: clove oil, LA, and 10% neutral-buffered formalin. After 24 hours of fixation in each solution, a total of 21 tissue samples were analysed, with seven samples fixed in each of the three fixatives. These tissues underwent routine processing and were stained using haematoxylin, and eosin (H&E). Two blinded oral pathologists then conducted a qualitative assessment of the samples under a compound microscope to evaluate the efficacy of each fixative. The criteria used for histopathological assessment were (a) staining quality (b) cellular quality (c) absence of tissue fragments (d) stroma morphology.
Results: In our study, LA demonstrated superior cellular and staining quality. Moreover, tissues fixed in clove oil exhibited fewer instances of tearing and fragmentation compared to other fixatives. The morphology of the stroma was found to be comparable across all three groups.
Conclusion: Given the current necessity for readily accessible tissue fixatives, our initial research indicates that clove oil (eugenol), commonly used in dental practice, shows potential as a promising fixative. However, further studies on human tissues are needed to confirm these findings.