We would like to make a few comments on the article entitled “Surface deterioration and elemental composition of retrieved orthodontic miniscrews” published in the April supplement (Patil P, Kharbanda OP, Duggal R, Das TK, Kalyanasundaram D. Am J Orthod Dentofacial Orthop 2015;147[4 Suppl]:S88-100). The authors evaluated how contact with bone and soft tissue affects the surface of successful and failed retrieved miniscrew implants (MSIs). Energy dispersive x-ray microanalysis (EDX) was performed to determine the elemental composition of the surface of the MSIs.
However, the retrieved MSIs were analyzed after they were “gently washed,” and the organic debris was removed afterward by a cycle of ultrasonic cleaning with enzymatic detergent. By doing so, the EDX identified not only the elements from the structure of the MSIs, but also those from the organic debris adhering to the surface of the MSIs, incorporated because of the prolonged contact with oral tissues, biologic fluids, blood and exudates, saliva, and food. This can be confirmed by the presence of elements such as iron and calcium on the surface of the retrieved MSIs that were not found on the as-received MSIs.
The authors concluded that “The surface elemental composition of retrieved MSIs differs from that of as-received MSIs,” giving the idea that an alteration in the superficial structure of the retrieved MSIs had been identified. However, the values obtained with the EDX demonstrate evident contamination of the surface of the MSIs by organic debris and not modification of the elemental composition of their surfaces.