The goal of this randomized, controlled, single-center study is to compare the effects of Emdogain®, a regenerative biomaterial, on post-operative pain, wound healing and inflammation of treated sites after surgical crown lengthening. The main question it aims to answer is:

Does the use of Emdogain® in conjunction with crown lengthening surgery improve post-operative soft-tissue healing, decrease inflammation and reduce patient perception of pain compared to crown lengthening without addition of Emdogain®? The treatment group will receive Emdogain® during surgery, and the control group will undergo standard crown lengthening without Emdogain®.

This randomized, controlled, single-center study intends to investigate the effects of Emdogain® on wound healing, postoperative pain and inflammation of treated sites after crown lengthening procedures on a single site, and to compare the results of this therapy with those of standard crown lengthening treatment on a single site. We have hypothesized that the use of Emdogain® in conjunction with crown lengthening surgery improves post-operative soft-tissue healing, decreases inflammation and reduces patient perception of pain compared to crown lengthening without addition of Emdogain®. Patients were recruited from the Graduate Periodontology clinic at the Faculty of Dentistry, University of Toronto. These patients were referred to the department by dental students in the faculty as well as dentists and dental specialists within the community for crown lengthening surgery, and were subsequently screened for eligibility to participate in the study. After confirmation of eligibility and completion of recruitment, patients were randomized, using a computer-generated randomization table, into the following groups:

• Treatment/experimental group: patients undergoing surgical crown lengthening of a single site with application of PrefGel® + Emdogain®
• Control group: patients undergoing surgical crown lengthening of a single site with application of PrefGel® only

Inclusion Criteria:

Patients who:

• Were capable and willing to provide consent and complete treatment as well as follow-up appointments
• Were over the age of 18 years old
• Required surgical crown lengthening for functional reasons as outlined in background
• Had no contraindications to surgery (these include periodontal contraindications to crown lengthening such as poor crown-to-root ratio, furcation exposure or esthetic concerns)

Exclusion Criteria:

• Patients who were unable to provide informed consent
• Pregnant women
• Women receiving estrogen therapy
• Patients who had received systemic antibiotics within the past 6 months
• Patients with severe systemic disease (ASA 3+) including: poorly controlled diabetes, blood dyscrasias, liver disease, immunosuppressive disorders, malignancy or who have had previous radiotherapy
• Patients with untreated, active periodontal disease

All participants remained blinded with respect to their group assignment for the duration of the study. Allocation concealment was done by placing randomization codes with group assignment in opaque sealed envelopes that were opened by the operator at the end of the surgical procedure, right before suturing, which means the surgeon was blinded throughout most of the treatment.

Data was collected by a separate examiner who was also blinded to treatment allocation. Data analysis was carried out by an external statistician, minimizing the risk of bias.