Radiographic Bone Changes Following Socket Preservation in Mandibular Molars Using Deproteinized Bovine Bone Mineral Versus Using Beta Tri Calcium Phosphate
Radiographic Bone Changes Following Socket Preservation in Mandibular Molars Using Deproteinized Bovine Bone Mineral Versus Using Beta Tri Calcium Phosphate
Inadequate ridge width to allow implant placement, it noted that when extraction takes place and ridge preservation is not utilized the site of extraction could lose 40% to 60% of bone height and width within 2 to 3 years and subsequent loss of 0.25% to 0.5% annually. it reported as much as 4 mm loss of ridge width in extraction alone sites within 6 months. Using an atraumatic tooth extraction technique preserves osseous walls thereby improving the chances of osseous graft success.
The goal of ridge preservation is minimizing bone loss to preserve the maximum final, healed ridge dimensions.
Socket preservation is done using a hard tissue graft like xenograft bone or synthetic bone substitutes and prevent hazard of surgical intervention which needed during implant loading due to bone resorption.
Good assessment whether a particular graft is more beneficial than others which can be improve the extraction site healing.
Good assessment if grafting has any beneficial or detrimental effects on post-operative sequelae post extraction.
Extraction is indicated when a tooth cannot be restored or maintained in suitable conditions for long-term health, function, and/or esthetics. Loss of a tooth has a direct effect on life quality by impairing the ability to masticate, speak, and, in some instances, socialize, after tooth extraction an average alveolar bone loss of 1.5-2 mm (vertical) and 40%-50% (horizontal) occurs within 6 months, alveolar dimensional changes occur during the first 3 months. If no treatment to restore the dentition is provided, then continued bone loss occurs and up to 40%-60% of ridge volume is lost in first 3 years . And the absence of a tooth in its alveolus enhances a cascade of biological events that typically result in significant local anatomic changes..
Studies have demonstrated that loss of alveolar ridge Post extraction is an irreversible process result in both horizontal and vertical reduction. Atrophy of alveolar ridge may have a significant effect on tooth replacement therapy, especially when implant restorations are planned.
Therefore, alveolar ridge preservation has become a key component of contemporary clinical dentistry.
Past therapy attempts to prevent resorption of alveolar ridge were performed by root retention, with the primary goal of maximizing the stability of removable prostheses. In spite of that, root retention is not always practical because of fracture, caries, and/or strategic reasons.
Alveolar ridge preservation via "socket grafting" started in the mid-1980s as a therapeutic alternative to root submergence. Its use was rationalized on the opinion that "filling" the space left by the extracted tooth with a biomaterial would simulate a "root retention effect" conducive to bone preservation, which would subsequently facilitate placement of implant by reducing the need of additional grafting procedures. This approach gained popularity over the years because of its conceptual attractiveness and simple technical procedures.
Over the past twenty years, multiple studies evaluating the efficacy of different socket-filling access have been conducted. In these studies, many of biomaterials have been employed, including autologous bone, bone substitutes (allografts, xenografts, and alloplasts), bioactive agents, and autologous blood-derived products.
Use of a grafting material with or without a membrane (alveolar ridge preservation) give additional support for stabilization of blood clot and space maintenance, bone loss is reduced from 69% to 25% or less. Objective of alveolar ridge preservation reduces bone loss, reduce the need for additional bone, and provide soft tissue support. And sinus augmentation procedures . finally providing for easier implant placement and a higher potential of achieving an esthetic restorative outcome.
Ridge preservation procedures are indicated when buccal plate thickness less than 1.5-2mm (most anterior and esthetic zones), damage or loss of one or more socket walls, maintaining bone volume is crucial to minimize the risk to adjacent anatomical structures, patients where many teeth are being extracted and preservation of bone is important for further restoration, and patients with high esthetic demands such as a high lip line and thin biotype, which are more prone to tissue loss.
Xenogenic Bone Grafts (Xenografts): Xenografts are derived from other species; Grafts are harvested from animals, mainly cows. That is why this is processed to make it totally biocompatible and sterile.
Advantages of xenografts:
- Only one simple procedure is needed as the bone is not being harvested from the patient in dangerous surgical procedures and it will encourage Natural bone growth.
Disadvantage of xenografts:
Is the minimal risk of bovine sponge form encephalopathy due to the fact that all organic components of the bone are extracted? The most widely used xenograft bone is deproteinized bovine bone mineral. Xenograft bone has similar properties to human cancellous bone, in its crystalline content and its macrostructure; it also has similar physical properties to the human bone This is a purely mineral graft and is osteoconductive but also some resorption will happen, so its use also has limitation. When used in a particulate form it is mixed with the patient's blood and packed into the defect.
They are materials with their organic components totally removed, With their removal, concern about immunological reactions becomes nonexistent, The remaining inorganic structure provides a natural architectural matrix as well as an excellent source of calcium The inorganic material also maintains the physical dimension of the augmentation during the remodeling phases.
choice of comparators: Alloplasts are synthetic bone substitutes. They are made of inorganic biocompatible materials including synthetic hydroxyapatite, tricalcium phosphate, bioactive glass, and calcium carbonate. Whether synthetic hydroxyapatite is resorbable or nonresorbable depends on the temperature at which it is prepared.
High-temperature preparation of hydroxyapatite results in a nonresorbable, dense material, nonporous, which is used as filler. Tricalcium phosphate acts as filler and is partially resorbable. Calcium carbonate, which is derived from coral, is biocompatible and resorbable so that it acts as filler, which eventually may be replaced by new bone. Bioactive glass is a silicone-based, osteoconductive material that bonds to bone through the formation of carbonated hydroxyapatite.
The advantage of alloplasts is that they have no potential for disease transmission.
Among the most promising is the tricalcium phosphate , an alloplastic ceramic material studied and used extensively in the past decade. It is considered to be bioactive (by means of inducing specific biologic reactions) and (not stimulating inflammatory or foreign-body giant cell activity) biocompatible.
This is mainly because tricalcium phosphate is composed of Ca and P ions, which are the most commonly found elements in bone. However, tricalcium phosphate cements have a slower resorption rate than bone and are usually too dense to allow bone tissue to grow into the defect in a limited period of time.
By adding a faster resorbing material, pores may be created, ensuring new bone tissue growing into the defect.
Tricalcium phosphate as a bone graft substitute has been evaluated at length in previous studies. It binds to bone by means of mechanical anchorage with no formation of intermediate apatite layer. Bioresorption of tricalcium phosphate granules occurs due to chemical dissolution in biological fluids and cellular degradation.
Solubilization is induced by mesenchymal cells, which are also actively involved in the degradation process.
the capability of osteoplastic cells, fibroblasts, and osteoclasts to degrade TCP ceramic material. Monocyte/macrophage participation is well documented in vivo as well as in vitro.
It seems that the more soluble a CaP ceramic, the more rapidly it is resorbed by osteoclasts. However, the increased number of released calcium ions may, on one hand, inhibit osteoclasts' activity, while on the other hand, it provides a good environment for osteogenesis. Therefore, it seems that Tricalcium phosphate resorption is performed at a rather unpredictable rate that does not always correspond to the new bone formation rate. This behavior is evident in the conflicting results of many studies on the bioresorption of TCP.
The βeta- phase isomer of Tricalcium phosphate (β -Tricalcium phosphate ), however, is characterized by homogenous microporosity, physiologic pH, increased solubility, and a more predictable resorption rate that look alike the new bone remodeling rate. Composition or impurities Variations may affect solubility, whereas the pure phase seems to be resorbed in 5 to 6 months.
It should be noted that a faster resorbable material might allow soft-tissue cells to prematurely intrude into the defect, while slowly resorbable or nonresorbable materials that remain for a long time may inhibit new bone deposition.
Inclusion Criteria:
Exclusion Criteria
waw2sad@yahoo.com01006881803 ext. 002
01009612708 ext. 002