An interventional study of Enamel Matrix Derivative (Emdogain®) in Alveolar Bone Loss, Periodontal Pocket and Impacted Tooth With Abnormal Positioning, sponsored by Aristotle University Of Thessaloniki. Recruiting at 2 sites in Greece. Open to participants aged 18 Years to 35 Years. Per ClinicalTrials.gov, last updated 2026-07-22.
Sponsored by Aristotle University Of Thessaloniki · Not applicable, Interventional, and Prevention
This study investigates whether the intraoperative application of a specialized regenerative gel (Emdogain®) can improve the periodontal health of the mandibular second molar by preventing or reducing the formation of tissue defects after the surgical removal of an adjacent impacted lower wisdom tooth.
Surgical extraction of a lower wisdom tooth frequently leaves a deep pocket or a permanent hard and/or soft tissue defect on the back side of the neighboring second molar. This defect compromise the surrounding tissues and predispose the healthy second molar to future complications like root caries, dentin hypersensitivity, or localized gum disease. While most existing treatments address these defects after they have formed, this trial evaluates a site-specific preventive approach during the extraction process itself.
The study will involve 70 systemically healthy adults (ages 18-45) requiring surgical removal of a horizontally or mesially oriented impacted lower third molar. Participants will be randomized into two equal groups:
The Test Group: Will receive root conditioning with PrefGel and a single application of Emdogain® gel directly to the root surface and socket immediately after tooth removal.
The Control Group: Will undergo identical surgery but will follow a natural, spontaneous healing process without the application of any biomaterials.
The main objective is to measure changes in Clinical Attachment Level (CAL) at the distal aspects of the second molar using stable vertical anatomical reference points over a 6-month period. The trial will also monitor secondary healing parameters, including probing pocket depths, gum recession, radiographic bone level changes using standardized jigs, postoperative pain, swelling, and early tissue healing dynamics.
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.
318 studies on the registry are indexed under Alveolar Bone Loss; 79 are open to participants now.
This study's planned enrollment of 70 is above the median of 25 across 269 interventional studies indexed under Alveolar Bone Loss.
Browse Alveolar Bone Loss studies →Aristotle University Of Thessaloniki is the lead sponsor of 282 studies on the registry; 55 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants in this arm will undergo standardized surgical extraction of the impacted mandibular third molar. Following extraction and thorough debridement of the defect, the exposed distal root surface of the adjacent second molar will be conditioned with 24% EDTA (PrefGel). After rinsing, Enamel Matrix Derivative (Emdogain®) will be applied directly to the site prior to standard suturing and primary closure.
Other: Enamel Matrix Derivative (Emdogain®)
Participants in this arm will undergo the identical standardized surgical extraction of the impacted mandibular third molar and thorough debridement of the defect. No root conditioning agents or regenerative biomaterials will be applied. The extraction socket and distal defect will be allowed to heal spontaneously via natural blood clot formation prior to standard suturing and primary closure.
Application of 24% EDTA root conditioning gel (PrefGel) followed by the application of porcine-derived enamel matrix proteins (Emdogain®) to the distal root surface of the mandibular second molar prior to wound closure.
Also known as: Enamel Matrix Proteins, Amelogenin, Straumann Emdogain, EMD
Change in Clinical Attachment Level (CAL)
Clinical Attachment Level (CAL) is a measurement of periodontal health indicating the position of the soft tissue attachment on the tooth root, measured in millimeters (mm) using a calibrated periodontal probe. It will be recorded at seven distinct sites on the mandibular second molar. For the distal sites directly adjacent to the extraction socket, fixed coronal reference points will be used to calculate relative CAL, as the cementoenamel junction (CEJ) is often compromised by the impaction. For the remaining four sites on the second molar, the standard CEJ will be utilized as the fixed anatomical reference point. A reduction in the distance from these reference points to the base of the periodontal pocket over time indicates a clinical gain of tissue attachment and successful healing.
Time frame: Baseline (immediately prior to surgery) and 6 months post-surgery
Change in Radiographic Alveolar Bone Level
The vertical distance from the CEJ to the alveolar bone crest at the distal aspect of the mandibular second molar. Measurements will be conducted using standardized intraoral radiographs taken with the parallel cone technique and an individualized occlusal jig to ensure precise spatial reproducibility. The images will be calibrated using radiopaque spheres to account for magnification and will be evaluated by three independent, masked observers.
Time frame: Baseline (immediate post-operative) and 6 months post-surgery
Change in Probing Pocket Depth (PPD)
Distance from the free gingival margin to the base of the periodontal pocket, measured in millimeters (mm) using a calibrated periodontal probe at the seven designated sites around the mandibular second molar (as defined in the primary outcome).
Time frame: Baseline (immediately prior to surgery) and 6 months post-surgery
Change in Gingival Recession (REC)
Distance from the cementoenamel junction (CEJ) or fixed coronal reference point to the free gingival margin, measured in millimeters (mm) using a calibrated periodontal probe at the seven designated sites around the mandibular second molar.
Time frame: Baseline and 6 months post-surgery
Change in Bleeding on Probing (BOP)
A dichotomous index (yes/no) assessing the presence or absence of bleeding after periodontal probing at the six sites around the mandibular second molar. It acts as a clinical indicator of localized tissue inflammation.
Time frame: Baseline and 6 months post-surgery
Change in Plaque Index (PI)
Assessment of the presence or absence of supragingival dental plaque on the surfaces of the mandibular second molar, recorded to monitor the patient's oral hygiene compliance throughout the healing phase.
Time frame: Baseline and 6 months post-surgery
Postoperative Facial Oedema
Assessment of postoperative extraoral swelling. This is quantified by measuring the distances between specific anatomical facial landmarks using a flexible measuring tape.
Time frame: Baseline (pre-operative) and 7 days post-surgery
Postoperative Trismus (Maximum Interincisal Opening)
Measurement of maximum mouth opening capability to assess postoperative trismus. It is recorded as the maximum vertical distance in millimeters (mm) between the incisal edges of the maxillary and mandibular central incisors.
Time frame: Baseline (pre-operative) and 7 days post-surgery
Postoperative Pain
Patient-reported postoperative pain intensity evaluated daily using a Numeric Rating Scale (NRS) ranging from 0 (no pain) to 10 (worst imaginable pain). Additionally, the total number of analgesic tablets consumed by the patient will be recorded via a patient diary.
Time frame: Daily for the first 7 days post-surgery
Oral Health-Related Quality of Life (OHIP-14)
Patient-reported outcome assessing the impact of the surgery on daily life using the validated 14-item Oral Health Impact Profile (OHIP-14) questionnaire. Total scores range from 0 to 56, with higher scores indicating a greater negative impact on the patient's quality of life.
Time frame: Baseline (pre-operative), 7 days post-surgery and 6 months post-surgery
Change in Sleep Quality
Assessment of postoperative sleep quality and disturbances using the validated Patient-Reported Outcomes Measurement Information System Sleep Disturbance Short Form 8a (PROMIS-SD SF 8a). This instrument specifically evaluates sleep quality over a 7-day recall period. It consists of 8 items, yielding a total score ranging from 8 to 40. Higher scores indicate greater sleep disturbance and a worse postoperative sleep experience.
Time frame: Baseline (pre-operative) and 7 days post-surgery
Plan to share: Undecided
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