Regenerative Gel (Emdogain®) for Healing After Wisdom Tooth Extraction

The primary objective of this two-center, parallel-group, randomized clinical trial is to investigate whether the intraoperative application of Enamel Matrix Derivative (EMD) can improve the long-term periodontal health of the mandibular second molar by preventing or minimizing the formation of distal tissue defects following third molar surgery. While the regenerative properties of EMD are well-documented in periodontology, the novelty of this study lies in its prophylactic, site-specific usage at the immediate time of extraction.

Methodology and Standardization

To maximize data reproducibility and minimize measurement errors, the study incorporates the following rigorous standardization protocols:

Anatomical Selection: To control for surgical site variables and baseline defect morphology, inclusion is strictly limited to patients presenting with horizontally or mesially oriented impacted mandibular third molars.

Clinical Measurement Protocol: Clinical parameters are recorded at seven distinct sites around the mandibular second molar: mesio-buccal, mid-buccal, disto-buccal, mesio-lingual, mid-lingual, disto-lingual, and mid-distal. Because the adjacent third molar, the surrounding soft tissue, and limited clinical visibility obscure the distal cementoenamel junction (CEJ) preoperatively, stable and reproducible vertical anatomical landmarks are utilized as reference points for all measurements adjacent to the extraction defect. The disto-buccal site is measured from the distal-buccal cusp tip; the disto-lingual site is measured from the distal-lingual cusp tip; and the mid-distal site is measured from the permanent occlusal (masticatory) surface of the second molar. The remaining four sites (mesio-buccal, mid-buccal, mesio-lingual, and mid-lingual) will be measured from the standard CEJ landmark as usual.

Examiner Calibration: All clinical measurements are performed by a single investigator who undergoes intensive pre-study calibration sessions targeting an intra-examiner intraclass correlation coefficient (ICC) ≥0.85, with scheduled recalibration to prevent measurement drift over time.

Radiographic Calibration and Alignment: To eliminate radiographic distortion and magnification errors, a calibration sphere (metal ball) with a fixed, known diameter of 5 mm is attached to the radiographic setup. Digital image analysis software utilizes the true dimensions of this 5 mm ball to calculate the precise, absolute bone level distances via a standard proportional scale (rule of three). All radiographs are captured using the long-cone paralleling technique, standardized via a customized film-positioning device and repeatable radiographic jigs to ensure identical alignment across all time points.

Study Arms and Follow-up:

Seventy systemically healthy participants (ages 18-45) are randomized to either the Test Arm (debridement, root conditioning with PrefGel, and site-specific application of Emdogain® gel) or the Control Arm (identical surgical protocol allowing for spontaneous healing via a natural blood clot). Both groups receive standardized postoperative pharmacological and oral hygiene care. Early soft-tissue healing and patient-reported outcomes are monitored during the first week, while definitive soft- and hard-tissue periodontal remodeling is evaluated at 6 months postoperatively.

Inclusion criteria

• Healthy adult patients aged 18 to 35 years old (ASA I or II).
• Presence of an asymptomatic, partially or fully impacted mandibular third molar requiring surgical extraction.
• The third molar impaction must be mesioangular or horizontal, with its crown in direct physical contact with the adjacent second molar, as assessed by a preoperative panoramic radiograph.
• The adjacent mandibular second molar must be vital, fully erupted, and structurally sound (free of extensive dental caries or prosthetic crowns).
• Patients must demonstrate an adequate level of overall oral hygiene and gingival health (e.g., Full-Mouth Plaque Index < 20% and Full-Mouth Bleeding Score < 20% following initial prophylaxis and oral hygiene instructions).
• Willingness to comply with postoperative instructions and adhere to the scheduled follow-up visits.
• Ability to understand the study procedures and voluntarily sign the informed consent form.

Exclusion criteria

• Presence of systemic diseases or conditions that could compromise wound healing or periodontal health (e.g., uncontrolled diabetes mellitus, autoimmune disorders).
• Current or recent use of medications known to affect bone metabolism or wound healing (e.g., bisphosphonates, long-term systemic corticosteroids, immunosuppressants).
• History of heavy smoking (e.g., >10 cigarettes per day) or use of smokeless tobacco products.
• Pregnant or lactating females.
• Diagnosis of periodontitis (Stage II, III, or IV) affecting the remaining dentition, excluding the localized defect associated with the impacted third molar.
• Presence of active acute infection (e.g., purulent pericoronitis) or radiolucent pathologic lesions extending beyond the normal follicular space (e.g., dentigerous cysts) that would significantly alter the baseline bony defect morphology.
• Known allergy or hypersensitivity to any of the medications utilized in the surgical or postoperative protocol (e.g., local anesthetics, prescribed antibiotics, or analgesics).
• Previous orthodontic treatment utilizing bands on the mandibular second molars that could have affected the periodontal attachment.