حفاظت از ناحیه جلویی دهان با استفاده از یک ماده پیوندی مصنوعی Alveolar Ridge Preservation Using a Novel Synthetic Grafting Material: A Case with Two-Year Follow-Up

1. Introduction Clinical and experimental studies have shown that grafting the postextraction sockets at the time of tooth extraction with a bone grafting material constitutes a predictable and reliable way to limit the resorption of the alveolar ridge [1–3]. Such alveolar ridge preservation measures involve the use of a wide variety of bone substitutes, barrier membranes, and biologically active materials, and many di?erent surgical techniques and protocols have been proposed [4–6]. According to Yip et al. [7], the ideal grafting material should have speci5c attributes. It should be osteoconductive, osteoinductive, and biocompatible. It is important to be totally replaced by host bone having an appropriate resorption time in relation to new bone formation. Moreover, it should be able to maintain the volume stability of the augmented site, have satisfactory mechanical properties, and have no risk of disease transmission. Allografts, xenografts, and synthetic particulate materials, with or without a membrane, have been extensively used and documented, showing adequate results in the preservation of the ridge dimensions [5]. It is important that these bone substitutes vary in terms of origin, composition and biological mechanism of function regarding graft resorption and new bone formation, each having their own advantages and disadvantages [8, 9]. Alloplasts represent a group of synthetic osteoconductive, biocompatible bone substitutes that are free of any risk of transmitting infections or diseases by themselves, and their availability is unlimited [10–12]. One of the most promising groups of synthetic bone substitutes is calcium phosphate ceramics, and among them beta tricalcium phosphate (β-TCP) is commonly used [13–15]. Apart from being osteoconductive, there is strong experimental evidence that calcium phosphates also have osteoinductive properties. Although the underlying mechanism remains largely unknown, it has been shown that these alloplastic materials can stimulate osteogenic di?erentiation of stem cells in vitro and bone induction in vivo [16, 17]. ,e ability of the bacteriostatic calcium sulfate (CS) to set and hence be stable is well documented. Adding CS to β-TCP produces an in situ hardening grafting material that binds directly to the host bone, maintains the space and shape of the grafted site, and acts as a stable sca?old [18–23]. ,e improved stability throughout the graft material seems to further improve the quality of the bone that will be regenerated due to reduced micromotion of the material, which may lead to mesenchymal di?erentiation to 5broblasts instead of osteoblasts. It is known that micromovements between bone and any implanted grafted material prevent bone formation, resulting in the development of 5brous tissue [24, 25]. Moreover, the CS element creates a nanoporous cell occlusive membrane that may prevent the early stage invasion of unwanted soft tissue cells into the graft [26, 27].