Comparison of Freeze-Dried Amniotic and Collagen Membranes for Soft Tissue Healing After Grafted Implant Surgery

This prospective interventional in vivo study was conducted in the Department of Advanced Dental Sciences, Rajas Dental College and Hospital, to compare the effectiveness of Freeze-Dried Amniotic Membrane (FD-AM) and Collagen Membrane (CM) in promoting soft tissue healing following Stage I implant surgery with particulate bone grafting.

A total of 10 partially edentulous patients with bilateral posterior maxillary edentulous sites meeting the predefined inclusion and exclusion criteria were recruited. The study employed a split-mouth design in which each patient contributed two implant sites, allowing direct within-patient comparison of the two membrane types. One site received FD-AM and the contralateral site received CM according to a randomization protocol based on a simple coin toss performed by an independent individual not involved in surgery or outcome assessment.

The study included patients aged 25-55 years presenting with bilateral posterior maxillary edentulous areas, immediate implant placement requirements following extraction, or delayed implant placement in ridge defects requiring grafting. Patients with smoking history, pregnancy, systemic diseases affecting bone metabolism, active periodontal disease, infectious diseases, vitamin D deficiency, or known allergies to study materials were excluded.

All surgical procedures were performed under aseptic conditions using standard implant surgical protocols. Following implant placement, xenogeneic demineralized bone matrix graft material (Osseograft) was placed around the implant site as required. Platelet-Rich Fibrin (PRF) was prepared from autologous venous blood and used to enhance the regenerative environment. Barrier membranes were adapted over the grafted sites to facilitate guided bone regeneration and were followed by primary wound closure using interrupted sutures.

The primary outcome measure was soft tissue healing assessed using the Early Healing Score (EHS) by a blinded examiner. Secondary outcome assessment included postoperative pain evaluation using a Visual Analogue Scale (VAS) and structured questionnaires administered during follow-up visits.

The study aimed to determine whether FD-AM provides comparable or superior soft tissue healing compared with conventional collagen membranes. The results demonstrated favorable healing responses with both membrane types, characterized by adequate hemostasis, absence of significant inflammatory signs, and satisfactory epithelialization during the early healing period. The findings suggest that both FD-AM and CM are effective barrier membranes for supporting early soft tissue healing and guided bone regeneration around dental implants.

Inclusion criteria

• Adults aged 25-55 years.
• Male and female participants.
• Bilateral posterior maxillary edentulous area in the premolar region (Bedrossian Zone 2 classification).
• Patients with teeth requiring extraction and eligible for immediate implant placement in the bilateral posterior maxillary region.
• Patients with ridge defects classified as Siebert Class II or Class III and eligible for delayed implant placement in the bilateral posterior maxillary region.

Exclusion criteria

• Current smokers.
• History of systemic diseases affecting bone turnover, including hyperthyroidism (T4 outside 5.0-12.0 μg/dL or T3 outside 80-220 ng/dL), Type I diabetes mellitus (HbA1c > 6%), Cushing's disease, or hyperlipidemia.
• Pregnant women.
• Lactating mothers.
• Presence of periodontal disease.
• Known allergy to study materials or medications.
• Blood-borne infectious diseases, including HIV or HBsAg positivity.
• Vitamin D level < 30 ng/mL.