The suitability of scanning electron microscopy in the evaluation of bone structure surfaces and selection of alloplastic materials for facial skeletal reconstruction

Abstract

Introduction: Functional and aesthetic problems can arise even from small losses created in the facial skeleton. Injuries and oncological surgeries are the most frequent causes of these losses within the facial skeleton. Advances in surgical interventions have allowed for ever-increasing degrees of resections, increasing oncological radicality as well as treatment effectiveness, providing the patient with the chance for a longer life. However, this subsequently requires the use of even more advanced reconstruction techniques in order to restore quality of life and comfort to the patient, as well as enable their return to professional and social activities. The necessity of reconstructive surgery applies not only to patients with cancer, but also to patients with impaired or failing sensory and organ function as a result of inflammatory conditions, injuries, or non-oncological surgeries. There are many available reconstruction procedures, which depend on the location of the loss, the type of tissue lost, the degree of loss and patient-dependent factors. Materials used in reconstruction surgeries may include the patients’ tissues when available, and artificial reconstruction materials otherwise. Material and methods: The analysis involved fragments of bone tissue removed during surgery. Due to the nature of the medical procedure and the inability to replant the tissue, it was regarded as medical waste. The preparations used were observed under an optical microscope and an electron scanning microscope, and a chemical analysis was performed. The chemical composition of samples was analysed using a low vacuum detector (LVD) at an accelerating voltage of 15 kV and 10 kV and at a spot size of 4 and 3.5. The observations were performed in a secondary electron (SE) detection system. Results: Observation of parameters under an optical microscope and of images obtained using an electron scanning microscope showed the presence of typical, compact bone tissue with varied surface shapes in each case (various degrees of unevenness and porosity). Chemical composition analysis confirmed the presence of compounds from the CaO-P2O5-H20 system. The Ca/P (calcium/phosphorus) ratio obtained from the chemical analysis varied from 1.33 to 2.1, and indicated a varied morphology of calcium phosphates forming the bone structures of the facial skeleton. Conclusions: 1. Calcium phosphates are characterised by excellent biocompatibility because of their chemical affinity to bone, and are ideal for the reconstruction of bone losses within the facial skeleton. 2. Biodegradable polymers have the highest functional potential among several groups of biomaterials used in tissue engineering because of their ability to be tailored individually, in addition to their high biocompatibility.