The purpose of this investigator-initiated study is to compare new bone formation through histomorphometric analysis following maxillary sinus augmentation using two different bone graft materials. A total of twenty, sinus augmentation via a lateral approach will be performed for subjects requiring sinus augmentation for implant placement and randomly divided into 2 groups. These subjects will receive one of two different bone graft materials: 1) Anorganic bovine bone matrix- InterOss (Group A), 2) Anorganic bovine bone matrix- Bio-oss (Group B). At the time of implant placement (eight months after the sinus augmentation procedure), two bone biopsies will be collected from augmented site for the histomorphometric analysis. The percentage of vital bone will be measured and analyzed statistically, also the following will be measured: percentage of non-vital bone, percentage of non-bone material , and the percentage of connective tissue.

Bovine xenograft has been established as a gold standard in maxillary sinus floor augmentation. This study was initiated to compare two different types of bovine xenografts following maxillary sinus floor augmentation. The comparison will performed using histomorphometric analysis of bone cores removed from the grafted sites. The patients that meet the guidelines for maxillary sinus floor augmentation via lateral window approach are randomly assigned into control and test groups. The surgery is performed by the same surgeon under the same protocols. The subjects in Group A - test group receive InterOss bone graft and subjects in Group B- Control Group receive BioOss bone graft. After eight months of healing at the sites, the patients are subjected to CBCT evaluation in preparation for implant placement. At the time of implant placement the two bone cores are collected from each grafted site using trephine burs. One bone core is collected from the crestal bone that will be site of implant placement and the second bone core is collected from the lateral window area not to interfere with the implant site. These bone cores are stored intact inside the trephine burs, fixed, stored and transported to the lab for histomorphometric analysis. The following parameters are measured and reported after the histomorphometric analysis.

percentage of vital bone percentage of non-vital bone ( graft material) percentage of non-bone material percentage of connective tissue.

Inclusion Criteria:

1. Over 18 years old who are able to read and sign an informed consent form.
2. Patient who has good oral hygiene (Full-mouth plaque score <25%).
3. Subject would be available for study monitoring and follow-up visits.
4. Patients with missing teeth in the maxillary posterior region who will require sinus augmentation for implant placement. The patients may be partially or completely edentulous.
5. Patient is a candidate for delayed implant placement approximately 8 months following sinus grafting

Exclusion Criteria:

1. Alcohol, drug dependency.
2. Signs or symptoms of chronic maxillary sinus disease.
3. Current smoker.
4. History of head and neck radiation treatment.
5. Poor health, conditions like uncontrolled diabetes, uncontrolled hypertension or other uncontrolled systemic disease.
6. Physical or psychological reason that might affect the surgical procedure or the subsequent prosthodontic treatment and/or required follow-up examinations.
7. Also, subjects who are nursing or pregnant will be excluded from the study.

These participants were selected for grafting of the maxillary sinus floor based on the minimum availability of the bone present in that area for implant placement.

Adverse events data collected through nine months after sinus augmentation