Twenty four patients with bone resorption on the anterior maxilla will be divided into two groups with different kinds of grafting: bone block associated with particulated biomaterial and particulated mixture of autogenous bone and biomaterial stabilized by collagen membrane and pins. The techniques will be compared according to volume gain, quality of graft osseointegration, implant survival and maintenance of the level of soft tissues.

Twenty four patients will be selected analysing the resorption on the front maxilla and will be divided into two groups. Experimental group will receive a particulated mixture of autogenous and lyophilized bovine bone, stabilized with a collagen membrane and pins over the vertical and/or horizontal defect, while Control group will receive a bone block graft, stabilized with fixation screws , covered with lyophilized bone and a collagen membrane. After a period of nine months, the volume increase will be measured trough the difference found between the initial computerized tomography and the final computerized tomography.

Dental implants will be placed according to the prosthetic need and bone cylinders will be removed from the respective location. The cylinders will be histologically analysed in order to verify the quality of the graft osteointegration. After the prosthesis installation, the implant survival and the soft and hard tissues will be followed up for a minimum period of 24 months.

Inclusion Criteria:

• absence of teeth at anterior maxilla
• need of vertical or horizontal bone reconstruction at anterior maxilla

Exclusion Criteria:

• smoking habits
• diabetes
• systemic diseases which interfere with osseous metabolism
• active periodontal disease