The objective of this randomized clinical study was to evaluate the use of dehydrated human amnion-chorion membrane as an exposed barrier for guided bone regeneration (GBR) after tooth extraction and to determine whether intentional exposure of this membrane to the oral environment compromises ridge dimensions and bone vitality for implant placement.

Forty-three patients requiring extraction of at least one tooth and delayed implant placement were randomly assigned to either an experimental or a control group. For both groups, demineralized freeze-dried bone allograft was used to graft the socket. For the control group, Type I bovine collagen was used as a membrane; for the experimental group, human amnion-chorion membrane was used. For both groups, the barrier membranes were left exposed, and no primary closure was achieved. Patients returned for implant placement after a mean healing period of 19.5 weeks, at which time a core bone biopsy specimen 2 mm in diameter was obtained for histomorphometric analyses. Clinical ridge dimensions were measured at the times of extraction and implant placement.

Inclusion Criteria: .

Patients included in the study were required:

• Not to be completely edentulous.
• To have at least 1 tooth that could not be saved and for which extraction and delayed implant placement were planned

Exclusion Criteria: Patients were excluded if they :

• Had received radiation therapy
• Were taking antiresorptive medication (i.e., bisphosphonate or denosumab)
• Had uncontrolled systemic disorders (such as uncontrolled diabetes, congestive heart failure, or acute odontogenic infections)
• Were smokers (more than 10 cigarettes per day)
• Were pregnant or breastfeeding.