Bone is a dynamic living tissue that is made up of metabolically active cells that are integrated into a rigid framework, 30% organic matrix, and 70% minerals. A vascular network of nutrient, metaphyseal, and periosteal vessels richly supplies adult bone. In a fracture or fusion model, the healing potential of bone, is decided by a variety of systemic and local factor including biochemical, biomechanical, cellular, hormonal, and pathological mechanisms. An incessantly occurring state of bone deposition, resorption, and remodeling facilitates the healing process (Kalfas, 2001). A lot of growth factors and regulatory proteins have been interlaced in bone repair.
INTRODUCTION Gypsum is scientifically named calcium sulfate dehydrate with the formula (CaSO4.2H2O). It is known to be a white powdery substance that is a naturally occurring mineral. The main form of calcium sulfate dehydrate used in dentistry is named calcium sulfate hemihydrate with the formula (CaSO4)2.H2O. Gypsum is mainly used for dental restorations and applications to replicate the patients’ oral cavity. Dies and models are created using the 5 gypsum products; impression plaster (Type 1), model plaster (Type 2), dental stone (Type 3), dental stone with high strength and low expansion (Type 4) and dental stone with high strength and high expansion (Type 5).
Hy¬droxyapatite (HAp) [Ca10(PO4)6(OH)2] is a naturally occurring mineral in the inor¬ganic component of human bone and tooth enamel. The crystal size of HA in natural human bone is in nano range. The constit¬uent ele-ments of HA areprimarily calcium and phosphorus, with a stoichiometric Ca/P ratio of 1.67.It displays favourable properties such as bioactivity, biocompati¬bility, slow-degradation, osteoconduction, osteointegration, and osteoinduction. HAp with a Ca/P ratio of 1.67 is the main min¬eral component of biological hard issues, such as bone and teeth and it is made up of calcium and phosphorous. It is known as a bio-ceramic because of its excellent bioac¬tivity and biocompatibility.
The bone of the jaw accepts and osseointegrates with the titanium post. Osseointegration refers to the fusion of the implant surface with the surrounding bone. When Are Dental Implants Used? Alternatives to dental implants have historically included dental bridges and dentures. Typically, conventional and cantilever bridges require shaping/grinding of the healthy teeth surrounding a missing tooth.
Perineural and bone invasion are commonly present. Our lesion showed biphasic solid and cribriform patterns with focal comedonecrosis. Immunohistochemical analyses have shown that SDC typically demonstrates usually expresses AR, CK7, CK AE1/3, GCDFP-15, 34bE12, EMA and CEA. Occasionally, it can be positive for S100, ER and PR. Androgen receptor is expressed significantly more often in salivary duct carcinomas of men than in salivary duct carcinomas of women.
Calcium sulfate (CS) (CaSO4) occupies a unique position among bone regenerative materials. It is used in clinical practice for long time than most currently available biomaterials and is widely recognized as a biocompatible material with applications in bone regeneration. It has the advantage that it is available and inexpensive (Thomas & Puleo, 2009). The ‘‘gypsum’’ or CS is a mineral consisting of calcium sulfate dehydrate (CaSO4.2H2O). It must be screened before use in medical practice for impurities such as silicates, lead, strontium, and other naturally occurring materials (Ricci, Alexander, Nadkarni, Hawkins, Turner, Rosenblum, Brezenoff, De Leonardis & Pecora, 2000).
Nutrient artery of tibia arises from either posterior tibial artery, anterior tibial artery or its branches at the level of the popliteal bifurcation (1, 2, 3). The position, size, direction, number and location of nutrient foramen are variable and may alter during the growth (4, 5). The vascular injury by traumatic reasons like fracture, bullet injury or by iatrogenic reasons during surgery or graft may affect the healing process in the bone; as it is dependent on blood supply (6, 7, 8). The incidences of nutrient foramina were also indicative of vascularity of the bone (9, 10). Clear knowledge on frequency and location of the nutrient foramina is necessary prior to planning surgical procedures to overcome the vascular injury.
It transmits the occlusal forces to the bones and acts as a shock absorber (Figure 4). It maintains the gingival tissues in their proper relationship to the teeth. It also shows a nutritional and sensory function (8). Figure 4: Function of periodontal ligament during shock absorption; a. Mandibular premolar in resting state; b. when force is exerted the tooth rotates around the axis of rotation (black circle on tooth) the periodontal ligaments are compressed in area of pressure and distended in areas of tension (8) Cementum: It is the calcified, avascular mesenchymal tissue that forms the outer covering of the anatomic root. The two main types of cementum are acellular (primary) and cellular (secondary) cementum, consisting of calcified interfibrillar matrix and collagen fibrils.
Abstract Fibrous Dysplasia is an uncommon bone disease due to an underlying gene mutation causing replacement of normal bone by fibro osseous connective tissue. It exists in mono and polyostotic forms.FD presents mostly between 3 and 15 years of age and without any gender variation. Bone pains and fractures are the most common presenting features. Radiological studies are done to support the diagnosis of FD. Recent evidences shows the efficacy of intravenous pamidronate in the treatment of FD along with other measures to maintain the maximum bone density.
In order from most common to least common they are, Osteosarcoma, Chondrosarcoma, Ewing Sarcoma, Fibrosarcoma, Malignant Fibrous Histiocytoma, and Chordoma. Osteosarcoma begins in bone cells that make new tissue, Chondrosarcoma begins in cartilage cells in the bone, Ewing Sarcoma tumors mostly develop in bones, but they can also appear on tissues and organs. Malignant Fibrous Histiocytoma (MFH) and Fibrosarcoma form more often in soft tissues such as ligaments, tendons, fat, and muscles. Chordoma usually occurs in the base of the skull and in the bones of the spine(Bone Cancer-Patient