Simplified Free Gingival Graft Around Implants Using Medical Grade Tissue Cyanoacrylate: A Case Series Report

Dental implant-supported oral rehabilitation has been widely utilized in modern dentistry. It is important to ensure the presence of a sufficient amount of attached keratinized gingiva around implant prosthesis to achieve long-term stability.^1,2  Often times, regardless of the types of alveolar augmentation procedures performed, a significant loss of attached keratinized gingiva and/or shallowness of the vestibule are observed afterwards. The lack of attached keratinized gingiva can lead to excessive movement of soft tissues around the implants, resulting in invasion of bacteria into the open sulcus.³  Unlike periodontal tissue in healthy natural teeth, the lack of attached tissue around a dental implant prosthesis may result in compromised resistance to bacterial invasion leading to marginal bone loss.^4–7 

Free gingival graft (FGG) procedures have been widely used for decades to increase the amount of attached keratinized gingiva.^8,9  Free gingival graft may be performed before the implant placement, during the uncovering stage or after the delivery of temporary/final implant-supported prostheses. Historically, various suturing techniques have been utilized to stabilize the donor graft tissue at the recipient site. However, conventional suturing is time-consuming and technique-sensitive. In order to overcome the drawbacks of suturing, at least 1 clinician proposed compressing the graft for several minutes, covering it with cellophane and then securing the latter with medical grade cyanoacrylate.¹⁰  The present short case report demonstrates that cyanoacrylate alone can be used to secure FGGs.

All patients were informed regarding the treatment procedure and signed written informed consents were obtained. Patients received prophylactic oral antibiotics prescribed as 500 mg of amoxicillin/potassium clavulanate (Augmentin, Ilsung Pharmaceutical Co, Seoul, Korea) before surgery and 250 mg of amoxicillin/potassium clavulanate was continued for 3 days postoperatively. All surgical procedures were performed under local anesthesia using articaine hydrochloride 4% with epinephrine 1/100,000 for a maxillary quadrant (Septanest; Septodont, Saint Maur Des Fosses, France).

A superficial horizontal incision was made at the muco-gingival junction and the incision line was extended to adjacent teeth at the same mucogingival line using a 15-c blade. Two superficial vertical incisions were made at the end of the horizontal incision and extended 4–5 mm into the vestibule. The recipient bed then was prepared as a split-thickness flap. Lip muscles were pulled in various directions for observation of any possible remaining movable soft tissue on the recipient site. This is critical since any mobility of FGG donor tissue during the early healing phase may lead to graft failure. The apically repositioned flap was then stabilized at the base of vestibule with 2 to 3 periosteal coated vicryl sutures (Ethicon, Raritan, NJ). The dimensions of the recipient bed were measured with a periodontal probe. Gauze moistened with sterile normal saline was placed on the recipient bed. Then donor tissue was taken from the patient's palate on the same side as the intended recipient site (Figures 1 and 2).

A horizontal incision was made on the hard palate at distance of 4–5 mm lingual from the alveolar crest at edentulous sites or 2 mm away from the lingual gingival crest at dentulous sites. The length of a horizontal incision was 2–3 mm longer than that of the recipient bed. FGG (0.5–1 mm thick) was harvested to exclude adipose or glandular tissue and minimize bleeding from the donor site (Figure 3). After removing the palatal tissue, N-butyl-2-cyanoacrylate (Histoacryl, B.BRAUN Surgical, S.A, Spain) was applied immediately on the donor site for hemostasis, and the area dried gently with a 3-way air syringe. Excess cyanoacrylate was removed with a cotton plier (Figure 4).

The FGG was contoured and placed on the recipient-site bed. To stabilize it, a few drops of cyanoacrylate were applied along the superior, anterior, and posterior margin of the graft, and immediately dried with gentle air blow from the 3-way air syringe (Figure 5). Cyanoacrylate was deliberately not placed along the inferior border to prevent the FGG donor graft from accidental adhesion to the vestibular mucosa and thus susceptible to movement as the mucosal tissue moved. Periodontal COE-pack dressing was applied to protect the wound site and provide compression to the FGG during the initial healing period. Periodontal dressing was removed after 7–10 days (Figures 6 and 7).

A 45-year-old male patient complained of masticatory difficulty due to loss of his mandibular right first and second molar and maxillary right first molar teeth. Flapless implant placement was performed after evaluation of bone volume using cone-beam computed tomography on July 9, 2004. A motor-driven 4-mm diameter tissue punch was used to excise soft tissue at the proposed implant placement sites. All excised soft tissue was kept in sterile saline moistened sterile gauze soaked to prevent dehydration (Figure 8); 3.75-mm wide and 10-mm long implants (Tapered Screw-Vent, Zimmer Dental Inc, Carlsbad, CA) were placed at all 3 edentulous sites. Appropriate healing abutments were attached to allow for nonsubmerged healing. Recipient bed was prepared during the same appointment. Approximately 20-mm long superficial horizontal incision was made at the muco-gingival junction and extended to distal portion of the site of second molar implant and anterior portion of first molar implant. Two vertical incisions were made at both ends of horizontal incision and extended to the base of vestibule. Three excised core tissues were positioned in the prepared recipient bed. The first tissue core was placed at the distal area of the second molar implant and the second tissue core was placed around the first molar implant. The last tissue core was placed in the middle of recipient bed (Figure 9). N-butyl cyanoacrylate was immediately applied along the 3 borders of the graft to achieve stability (Figure 10). COE pack was placed on the donor tissues to stabilize them. COE pack was removed after 1 week of healing. A final restoration was delivered after 3 months healing. Augmented attached keratinized gingiva is well maintained after 13 years loading on July 19, 2017 (Figure 11).

A 42-year-old female patient presented with a complaint of masticatory difficulty due to severe caries of the mandibular left second bicuspid, first molar, and second molar. These hopeless teeth were extracted with immediate implant placement. A provisional restoration was delivered after 4 months of healing (Figure 12). A muscle pull from the buccal frenum around the implants-supported prosthesis was noted. Long-term, this muscle pull could induce marginal bone resorption. Therefore, a cyanoacrylate assisted sutureless FGG was performed on May 3, 2011. A superficial horizontal incision was made at mucosa from lower left second premolar to second molar. After making a horizontal incision 1- to 2-mm away from buccal gingival crest, 2 vertical incisions were prepared at both ends of horizontal incision. Prepared apically repositioned flap was secured with 2 sutures at the base of buccal vestibule.

Cyanoacrylate was applied along upper margin and anterior and posterior margin of FGG and dried immediately with 3-way air syringe. COE pack was applied on FGG to stabilize it. The periodontal dressing and suture were removed 7 days postoperatively. An increased zone of attached keratinized gingiva and deepening of vestibule was observed at 7 days postsurgery and 5 year postloading (Figures 14 and 15).

A wide zone of attached gingiva is known to help maintain the health of dental implants by (1) facilitating effective daily patient homecare and (2) preventing subgingival plaque accumulation, which could lead to mucositis and/or peri-implantitis.^1,11,12  The FGG is considered the gold standard technique to achieve a sufficient zone of attached keratinized gingiva.^13–15  Numerous factors such as: (1) graft thickness, (2) atraumatic surgical technique, (3) method of stabilization, and (4) duration of graft stabilization influences graft shrinkage during healing period.¹⁶  The traditional FGG technique is to secure the transplanted tissue with sutures, but this can be time-consuming and technique-sensitive.¹⁷  Barbosa et al¹⁸  evaluated the dimensional changes in FGG when stabilized with ethyl cyanoacrylate or sutures and found similar degrees of graft shrinkage concluding that the amount of shrinkage was related to graft thickness rather than mode of graft fixation. Gingival grafts, thinner than 1 mm, showed a greater average successful treatment height.¹⁸  Their findings are different from those of Gümüş and Buduneli's¹⁹  study on graft shrinkage in FGG performed with cyanoacrylate. They compared dimensional changes in FGG with 3 different stabilization methods including: (1) conventional suture technique, (2) cyanoacrylate, and (3) microsurgery with 7-0 sutures using 2.5× magnification loupe and microsurgical instruments. The FGG group that was pressed into place at the recipient site for 5 minutes and then stabilized with cyanoacrylate revealed significantly less shrinkage and postoperative pain than the other groups using periosteal sutures. Total procedure time also was significantly less than the other groups.¹⁹  Short, atraumatic surgery using cyanoacrylate resulted in a favorable outcome.

Cyanoacrylate adhesive is known to have good biocompatibility while of offering hemostatic and bacteriostatic properties.^20–22  These adhesives have been used in medicine and dentistry for wound closure as an alternative to conventional sutures.^23–28  These adhesive have also used for hemostatic agents at extraction sockets and palatal donor sites.^29–32  In addition, the use of cyanoacrylate adhesives has resulted in less postoperative inflammation and good clinical and histological healing when compared to silk sutures. This is believed to be due to cyanoacrylate's function as a mechanical barrier against accumulation of foreign materials at the surgical site.^33–35  Unlike earlier reports where compression was applied with wet gauze on the graft for 5 minutes before applying cyanoacrylates,¹⁹  the present case reports demonstrate that uneventful healing is possible when the adhesive was applied immediately without applied pressure beforehand thereby reducing further the overall surgical time.

Sutureless FGG using only a cyanoacrylate adhesive eliminates the need for time-consuming and tedious suturing while minimizing trauma to the donor tissue with multiple needle punctures. Cyanoacrylate adhesives are easy to apply at palatal donor and recipient sites under moist conditions. Immediate hemostasis, faster wound healing, decreased inflammatory reaction, and less graft shrinkage were all achieved with the cyanoacrylate sutureless technique when compared with the conventional FGG with sutures technique.