Bone resorption after a tooth extraction is a generally accepted knowledge and has been demonstrated by many animal and human studies. Especially during the first three months followed by the tooth extraction, the volume of bone may change significantly without any interference. Thus, doing a ridge preservation procedure following the extraction is a common standard of care method to maintain the socket volume if implant placement is considered as a treatment option in the future. A variety of materials and methods have been used for ridge preservation. However, it's still inconclusive to determine the best material to maintain the ridge dimension, especially for membrane placement that allows for space maintenance to protect the grafting material. Furthermore, there is no evidence to show any treatment rationale is superior to any other ridge preservation method.

In general, the membrane serves the function of the barrier and space protector. The periodontal surgeon use membranes to exclude the epithelium growth and to limit the collapse of the soft tissue into the healing alveolar socket. Regarding resorbable and non-resorbable membrane materials, both serve the function of protecting the graft material from the oral cavity. However, there are also many demonstrating that without membranes the extraction socket healed nicely without any interferences. The question to us is: Do we need the membrane to exclude the epithelium or any kind of surgical dressing material is sufficient enough to preserve the volume of the extracted ridge?

The object of this study is to compare five popular membranes on the market that present different characteristics of the membranes.

The extraction and the grafting procedure involved in this study are standard of care. The investigators will extract the hopeless teeth and prepare the site for implant placement in 4 months.

The following products will be used during the study:

• Collatape (Zimmer Dental)- approved by the FDA (class III)
• Cytoplast (Osteogenics Biomedical)- cleared by the FDA
• OssixPlus (Dantum Dental)- cleared by the FDA
• Renovix-Plus (Salvin)- cleared by the FDA
• BioXclude (SNOASIS)-certificate from the American Association of Tissue Banking
• PuroⓇ, Zimmer Dental)- cleared by the FDA
• RegenerOssⓇ, Zimmer Dental) - cleared by the FDA

During the appointment for the implant placement. A bone core from all subjects in each treatment group will be collected from the augmentation site instead of drilling away. The sample will be evaluated for the following:

• % viable of bone
• % of connective tissue
• % of residual graft material

Inclusion Criteria:

• Subjects must between the ages of 18 and 80.
• Subjects must require removal of at least one maxillary premolar
• Subjects should benefit from an implant-supported crown.
• Subjects must have voluntarily signed the informed consent form.
• Subjects must be assessed as ASA I, ASA II by a member of the research team.

Exclusion Criteria:

• Medical conditions requiring the use of steroids.
• History of leukocyte dysfunction or deficiencies, bleeding deficiencies, renal failure, uncontrolled endocrine disorders, acquired immunodeficiency syndrome or hepatitis.
• History of neoplastic disease requiring the use of chemotherapy or irradiation to head and neck.
• Subjects who have diabetes mellitus.
• Subjects who have undergone administration of any investigational drug or device within 30 days of enrollment in the study.
• Alcohol or drug abuse.
• Subjects who are heavy smokers (greater than 10 cigarettes per day or cigar equivalents) or chew tobacco.
• Conditions or circumstances, in the opinion of the research team, which would prevent completion of study participation or interfere with analysis of study results, such as a history of non-compliance or unreliability.

The study population will consist of subjects presenting to the University of Pennsylvania School of Dental Medicine who require extraction of a hopeless tooth due to trauma, caries, or endodontic/periodontal reasons, and who are interested in replacing their tooth with a dental implant.