An interventional study of piezo-electric surgery and conventional open flap crown lengthening in Altered Passive Eruption, sponsored by Suez Canal University. Completed at 1 site in Egypt. Open to participants aged 20 Years to 40 Years. Per ClinicalTrials.gov, last updated 2026-10-21.
Sponsored by Suez Canal University · Not applicable, Interventional, and Treatment
The goal of this clinical trial is to compare and evaluate the effectiveness of conventional surgery and Piezo-surgery for the treatment of gummy smile.
The main question it aims to answer:
"Which of these treatment modalities (conventional open flap crown lengthening with rotary handpiece and Flapless crown lengthening with Piezoelectric ultrasound has the best clinical results with least morbidity and least relapse in treatment of gummy smile?"
Researchers will compare:
The primary outcome was the decrease in excessive gingival display by measuring the length of clinical crown and width of keratinized gingiva before and after treatment modalities.
The The secondary outcome was to measure the durability and possibility of relapse over 6 months after treatment with high patient satisfaction
For patients seeking long-term correction of excessive gingival displays, there are different treatment modalities. Both open flap and flapless with Piezo techniques showed improvement in the decrease in the amount of gingival display, while the flapless technique showed durable and satisfactory esthetics with less patient discomfort, less pain, inflammation and bleeding immediately after the procedure and through the follow up intervals. Also, the open flap technique showed satisfactory results to the patients but with more pain immediately after the procedure.
Suez Canal University is the lead sponsor of 159 studies on the registry; 36 are open to participants now.
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Exclusion Criteria:
15 Patients selected had a gummy smile with type 1B APE Following administration of local anesthesia (4% lidocaine with 1:100,000 epinephrine) at the surgical site, gingivectomy was performed through an internal beveled incision followed by a sulcular incision, allowing removal of the gingival tissue. After the sulcular incision, a minimal access approach was adopted: a tunneling procedure was carried out using a small mucoperiosteal elevator, limited to the facial surface and deliberately avoiding the interproximal areas in order to preserve the interdental papillae and maintain soft tissue integrity. Osteotomy was performed using a Woodpecker Piezo- Surgical tip UL48, which allowed precise and conservative bone removal to achieve the desired distance between the gingival margin and the alveolar bone crest without elevating a flap. The target biological width was ensured by maintaining approximately 2 mm between the bone crest and the cementoenamel junction. No sutures were placed.
Procedure: piezo-electric surgery
15 patients with type 1B APE gummy smile were treated using the conventional open flap approach: After administration of local anesthesia (4% lidocaine with 1:100,000 epinephrine) at the surgical site, gingivectomy was performed using a #15 surgical blade to remove the excess gingival tissue and to define the contour of the gingival margin, an internal beveled incision was then made at the buccal aspect of the involved teeth, followed by a sulcular incision to detach the remaining gingival collar. A full-thickness mucoperiosteal flap was then carefully reflected to provide accessibility to the alveolar crest. Bone recontouring was performed with surgical burs mounted on a rotary handpiece under copious irrigation until a distance of approximately 2 mm between the between the alveolar crest and the cementoenamel junction (CEJ) was achieved to re-establish the biologic width. Finally, internal vertical mattress sutures were placed at the interdental papillae using 4-0 black silk suture.
Procedure: conventional open flap crown lengthening
Flapless piezo-surgery technique used for aesthetic crown lengthening in patients with gummy smile
conventional open flap technique used for aesthetic crown lengthening in patients with gummy smile
The primary outcome was clinical crown lengthening.
The primary outcome was crown lengthening confirmed by measuring the increase of the relative gingival margin (RGM) in mm from the incisal edge of the vacum stent to the gingival margin before and after the treatment modalities.
Time frame: Baseline, 1 week, 3 months and 6 months post-operatively.
Secondary outcome was comparing the morbidity of the open flap group to the minimally invasive flapless group
Secondary outcome was comparing the morbidity of the open flap group to the minimally invasive flapless group, using visual analog scale (VAS score) ranging from 0 (no pain) to 10 (worst pain imaginable) at 24 hours and one week after the surgery.
Time frame: 24 hours and one week after the surgery.
Bleeding on probing
Measurement of bleeding on probing using the Binary system: 0= no bleeding 1= bleeding on probing
Time frame: Baseline, 1 week, 3 months and 6 months post-operatively.
Gingival Index
Gingival index (GI): according to (Löe, 1967) index system Scores (0-3) 0= Normal gingiva Natural coral pink gingiva with no inflammation 1. Mild inflammation, Slight changes in color, slight edema. No bleeding in probing. 2. Moderate inflammation, Redness, Edema and glazing. Bleeding upon Probing 3. Severe inflammation, Marked redness and edema/ ulceration/ tendency to bleed spontaneously
Time frame: Baseline, 1 week, 3 months and 6 months post-operatively.
Plaque Index
using (Löe, 1967) index system, scores (0-3) 0= Absence of microbial plaque 1. Thin film of microbial plaque along the free gingival margin 2. Moderate accumulation of plaque in the sulcus 3. Large amount of plaque in the sulcus or pocket along the free gingival margin
Time frame: Baseline, 1 week, 3 months and 6 months post-operatively.
Clinical attachment level (CAL)
Clinical attachment level (CAL) was measured in mm from the cemento enamel junction to the base of the gingival sulcus following the marked grooves.
Time frame: Baseline, 1 week, 3 months and 6 months post-operatively.
Pocket depth (PD)
Pocket depth (PD) was measured in mm from the gingival margin to the base of the gingival sulcus following the marked grooves
Time frame: Baseline, 1 week, 3 months and 6 months post-operatively.
Width of keratinized tissue (WKT)
Width of keratinized tissue (WKT) was measured in mm from the free gingival margin to the muco-gingival line following the marked grooves
Time frame: Baseline, 1 week, 3 months and 6 months post-operatively.
Relative bone level (RBL)
Relative bone level (RBL) was measured in mm from the incisal end of the vacuum stent to the bone crest, guided by the fixed grooves. And was recorded preoperative and immediately after the surgery by bone sounding technique.
Time frame: preoperative and immediately post-operative.
Plan to share: No
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From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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