Overview
This study investigates the healing of periodontal defects on the distal surface of the second lower molars after the surgical extraction of impacted third molars. Specifically, it compares the effectiveness of autologous tooth graft particles (derived from the extracted third molar) with bovine xenograft particles, using blood clot healing as a control.
Description
This study investigates the healing of periodontal defects on the distal surface of the second lower molars after the surgical extraction of impacted third molars. Specifically, it compares the effectiveness of autologous tooth graft particles (derived from the extracted third molar) with bovine xenograft particles, using blood clot healing as a control.
Lower third molars are the most frequently impacted teeth, and their extraction can sometimes lead to or worsen periodontal defects on the adjacent second molar. Previous studies have shown positive outcomes using various bone regeneration materials; however, autologous tooth grafts have recently emerged as a biocompatible, osteoconductive, and osteoinductive alternative with promising results. Despite this, there are no clinical studies directly comparing autologous tooth grafts and bovine xenografts in this context-justifying the present research.
A prospective, randomized split-mouth clinical trial with three arms will be conducted at the Complutense University of Madrid. Each patient will undergo bilateral lower third molar extractions under three conditions:
Group A (Test 1): socket filled with autologous tooth graft,
Group B (Test 2): socket filled with bovine xenograft,
Group C (Control): socket left to heal naturally with a blood clot.
The main objective is to evaluate the reduction in probing depth on the distal surface of the second molar six months post-extraction.
Secondary outcomes include postoperative pain, inflammation, trismus, complications, wound healing, and patient-reported outcomes (PoSSe questionnaire).
Approximately 30 patients will be included, with triple randomization (side of first extraction, use of graft, and graft type). Clinical and radiographic evaluations will be performed preoperatively, and follow-ups will occur at 48 hours, one week, three months, and six months.
The null hypothesis (H₀) states that there will be no periodontal differences between the two graft materials, while the alternative hypothesis (H₁) proposes superior periodontal outcomes with the autologous tooth graft compared to the bovine xenograft.
Eligibility
Inclusion Criteria:
- Adults (≥18 years old) of any sex, able to understand and follow study instructions.
- Patients requiring bilateral surgical extraction of impacted lower third molars in horizontal or mesioangular position.
- Presence of both lower second molars.
- Classified as ASA I or ASA II (according to the American Society of Anesthesiologists).
- Willingness to participate voluntarily and sign informed consent.
Exclusion Criteria:
- Age under 18 years.
- ASA physical status III, IV, V, or VI.
- Pregnant or breastfeeding women.
- Immunosuppressed patients.
- Current treatment with NSAIDs, anticoagulants, or acetylsalicylic acid.
- Previous or current treatment with bisphosphonates.
- Presence of oral dysplasia or precancerous lesions.


