Effect of Laser on the Bone Defects Healing in Rats: An Experimental Study

Bone healing includes the following steps: induction of acute inflammation, regeneration of parenchymal cells, migration and proliferation of parenchymal and connective tissue cells, synthesis of protein and extracellular matrix, remodelling of connective tissue and parenchymal component and collagen-forming [1]. Tooth extraction and removal of the chronic periapical lesion can cause the defects in the jaw bone. Healing of the bone socket is similar with bone healing in general and includes the following stages [2]: formation of a blood clot, organisation of the clot, making the epithelial cover of the surface of the wound, formation of the woven bone in the connective tissue filling, and replacement of the woven bone (which is characterized by lacunae not arranged in parallel rows) by the trabecular bone (the mature form of bone where collagen fibers in the bone matrix are organized into successive sheets or lamellae oriented in the same direction) and remodelling the socket [3]. Non-disturbed healing of bone defects and filling the wound with bone tissue is the main prerequisite for normal bone function. A period of approximately six months after creating a bone defect in humans (after tooth extraction or periapical surgery) is necessary for the formation of the lamellar bone and even more is needed following surgery for a defect to completely fill with mature bone tissue. An ideal technique for wound healing stimulation, inducing more rapid bone regeneration, has not been presented yet. The regenerative procedure has not been accelerated even with new bone substitute materials [4]. Numerous data from literature shows the stimulating effect of soft (low-power) lasers on the process of wound healing [5, 6]. This effect is characterized by proliferation of fibroblasts, faster collagen production and enhanced enzyme activity. However, there are no precise data concerning the influence of low-power lasers on the speed and degree of bone regeneration. The aim of this study was to evaluate the possible enhancing effect of the GaAlAs low-power laser on the rate of the healing artificially created osseous defects in rats.