Straumann Bone Ceramic (SBC) and BioOss will be used as bone grafting materials when there is a need for bone augmentation in the posterior upper jaw. 9 months later the bone formation is evaluated. The patients are followed for 3 years.The study hypothesis is that the SBC is not worse than BioOss.

Straumann Bone Ceramic (SBC) and BioOss will be used as bone grafting materials when there is a need for bone augmentation in the posterior upper jaw. The bone grafting materials will be placed into the sinus cavity,(a routine procedure), one material randomly at each side and a micro-implant will be inserted simultaneously. 9 months later the micro-implant is removed and a regular Straumann SLActive implant is inserted. The micro-implant is evaluated histologically. The site is evaluated every 12 months for 3 years in regards to clinical measurements. The study hypothesis is that the SBC is not worse than BioOss.

Study design: Prospective, randomized, open, controlled, single center, split mouth

Study population: 11 male and female patients at an age of between 18 and 80 years, affected by edentulism of both lateral-posterior maxilla and presenting two pneumatized maxillary sinuses and necessitating rehabilitation with implant-supported prostheses will be recruited in the study and treated by means of maxillary sinus floor augmentation and delayed implant placement.

Inclusion Criteria:

• Males and females, 18 years to 80 years of age
• The patients are at least partly edentulous in the both maxillary regions corresponding to the sinuses.
• A dental implant procedure is foreseen in both maxilla regions corresponding to maxillary sinuses.
• Patients must be expected to present a bilateral bone defect in the sinus area, which both need a sinus floor augmentation to place one or more dental implants each.
• Residual alveolar crest height of the lateral-posterior segments of the edentulous maxilla below the floor of each of the maxillary sinuses shall be
• less than 5 mm and at least 2 mm, as measured by Scanora - tomography Scans in the deepest floor of the sinus
• residual alveolar crest width should be at least in average more than 4mm as measured by Scanora - tomography scans
• Patients must be committed to the study and must sign informed consent.
• Oral hygiene Index less than 25%

Exclusion Criteria:

• Any systemic medical condition that could interfere with the surgical procedure or planned treatment
• Current pregnancy at the time of recruitment
• Physical handicaps that would interfere with the ability to perform adequate oral hygiene
• Alcoholism or chronically drug abuse causing systemic compromize
• Patients who smoke more than 10 cigarettes per day
• Medication which interferes with bone formation
• Conditions or circumstances, in the opinion of the investigator, which could represent a general contra-indication for surgical procedure or would prevent completion of study participation or interfere with analysis of study results, such as history of non-compliance, or unreliability
• Mucosal diseases such as erosive lichen planus
• History of local radiation therapy
• Presence of oral lesions (such as ulceration, malignancy)
• Severe bruxing or clenching habits
• Persistent intraoral infection
• Previous GBR (bone graft) or dental implant treatment in the posterior segments of the upper maxilla (foreseen implant site)
• Patients presenting clinical and radiological signs and symptoms of maxillary sinus disease
• Existing teeth in the residual dentition with untreated endodontic problems

3 years