Randomized, Controlled Study to Compare Straumann® VivOss™ to Geistlich Bio-Oss® in Sinus Floor Augmentation.

A randomized controlled clinical trial to investigate the capability of Straumann® VivOss™ compared to Geistlich Bio-Oss in sinus floor augmentation to demonstrate superiority of Straumann® VivOss™ compared to Geistlich Bio-Oss in regards to the ratio of newly formed bone to residual bone substitute.

This is a prospective, randomized, controlled study. The total study duration for each patient should be 9-14 months (from screening to last visit).

Enrolled subjects are randomized to one of the following groups:

1. Sinus floor elevation with Straumann® VivOss™
2. Sinus floor elevation with Geistlich Bio-Oss®

In total 6 visits per patient are scheduled in this study. The histological evaluation of the ratio of newly formed bone to residual bone graft, survival and success rate of study implants and adverse events (AEs) will be assessed.

The study devices Straumann® VivOss™ and Geistlich Bio-Oss are CE-(Conformité Européenne, meaning European Conformity) marked products.

Two centers, one in Germany and one in Switzerland will participate.

Eligibility Criteria:
Inclusion Criteria:

* Subject must have voluntarily signed the informed consent before any study related action
* Males and females with at least 18 years of age (including 18 years)
* Subject needs augmentation procedure in the sinus to prepare for implant placement.
* Subject must have a residual bone height of 2 to 4 mm.
* Adequate oral hygiene ((Full mouth plaque index (O'Leary, et al. 1972 ) \<25%) at baseline
* Adequate control of inflammation ((full mouth bleeding on probing (Ainamo and Bay 1975)) ≤25% at baseline

Exclusion Criteria:

* Systemic disease that would interfere with bone or wound healing and dental implant therapy (e.g. uncontrolled diabetes)
* Systemic disease that would interfere with bone or wound healing and dental implant therapy (e.g. uncontrolled diabetes)
* Any contraindications for general bone grafting and oral surgical procedures
* Any anomalies of the sinus that could interfere with planned procedures
* History of local irradiation therapy
* Local inflammation, including untreated periodontitis
* Medical conditions requiring chronic high dose steroid therapy
* Treatment with an investigational drug or device within a 30 day period immediately prior to surgery at visit 2, or expected participation in any other investigational drug or device study during the conduct of this trial.
* Antibiotic treatment or anti-inflammatory treatment within 4 weeks prior to surgery
* History of alcoholism or drug abuse
* Immunocompromised subjects
* Subjects who smoke \>10 cigarettes per day or tobacco equivalents or chew tobacco
* Conditions or circumstances, in the opinion of the investigator, which would prevent completion of study participation or interfere with analysis of study results, such as history of non-compliance or unreliability
* Physical or mental disabilities that would interfere with the ability to perform adequate oral hygiene
* Current pregnancy (pregnancy test) and breastfeeding women

Secondary exclusion criterium:

Defects of the Schneider Membrane