Comparison of routine decalcification methods with microwave decalcification of bone and teeth

The microwave oven has been used quite often for tissue processing, but there are very few studies describing its use in decalcification of bone or teeth. In this study we have attempted to decalcify bone and teeth using a microwave oven and compare the process and results with conventional decalcification methods.

The objectives of the study were to determine and compare routine decalcification with microwave decalcification of bone and teeth using 5% nitric acid, 5% formic acid, and 14% ethylenediaminetetraacetic acid (EDTA) with respect to speed of decalcification, preservation of tissue structure and staining efficacy.

In our study the total sample size used for both routine and microwave decalcification was 30 premolar teeth and 30 pieces of condyles. The three solutions were dilute nitric acid (5%), formic acid (5%), and EDTA (14%). Each set consisting of the same type of premolars and condyles in each of the three decalcifying solutions were used in both manual method and microwave method.

The results in the present study confirmed the fact that the microwave method using nitric acid was indeed the fastest decalcifying method needing just about 2 days for condyle and 4 days for premolars, compared with routine decalcification. The results also showed that the overall histological picture was good with EDTA and formic acid irrespective of the methods used. In the routine method, nitric acid gave poor cellular detail when compared with microwave method.

With our study we conclude that microwave oven decalcification is faster than routine decalcification irrespective of the decalcifying agents used. The tissue preservation and staining efficacy was good in microwave nitric acid decalcification compared to routine nitric acid decalcification. Both formic acid and EDTA show good tissue preservation and staining efficacy irrespective of the method used.