block bone grafts ; alveolar ridge augmentation ; complication
Abstract
The augmentation of hard and soft tissue deficiencies in replacement of missing anterior single tooth is critical to the esthetic outcomes. When considering the selection of an augmentation method, the morphology of the osseous defect may act as an important factor. The fewer the bony walls remain, the greater the need for autogenous block graft technique might be expected.
The use of autogenous bone graft represents the“ gold standard”for bone augmentation procedures, which provides adequate volume of the bone reconstruction and the bone quality does not show a difference from the density of the native hard tissue in implant to bone contact. The biomechanical distribution of stress occurs primarily where the bone is in contact with the implant and increased density of interfacial bone provides better distribution and transmission of stress. Ideally, block bone graft should provide crestal bone with adequate density to withstand the implant loading. In spite of gains in the volume and the density of the deficient bone, there might be some disadvantages in esthetic aspects like recession of adjacent gingival margin and loss of interdental papilla when proper and careful management of the gingival flap is not prepared. The cases in this report show horizontal and vertical hard tissue augmentation of alveolar ridge using autogenous block bone graft in replacement of missing anterior single tooth and gains in the width of the volume retained in the grafted area. However, some losses in the height of grafted hard tissue and some limitations of esthetic results were also found.
In conclusion, stability in maintenance of the vertical level in augmented area depends on the adjacent alveolar bone height. Barrier membrane serves as a preservation device for the grafted area protecting the autograft from postoperative resorption. In addition, careful handling of the soft tissue flap using fine surgical instruments and primary wound closure with tension-free sutures are important factors for soft tissue healing and prevent the barrier membrane from exposing, which in turn provides lower risks in further bone resorption or gingival recession.