Comparison of Cyanoacrylate Adhesives to Sutures in the Palate After Connective Tissue Graft

Comparison of Cyanoacrylate Tissue Adhesives to Polytetrafluoroethylene (PTFE) Sutures in the Donor Site of Connective Tissue Grafts- A Randomized Clinical Trial

Cyanoacrylate tissue adhesives have been successfully used for wound closure. The purpose of this clinical trial is to compare cyanoacrylate tissue adhesives to polytetrafluoroethylene (PTFE) sutures in the donor site of connective tissue grafts. Two groups of volunteers will randomly assigned to one of the two study groups. The wound closure at the palatal donor area will be achieved with polytetrafluoroethylene (PTFE) sutures in one group and with high viscosity cyanoacrylate tissue adhesives on the other group. The surgical procedure will be performed by one of three calibrated periodontics residents. Data will be collected at baseline-day of the surgery and in one week post-operatively. The primary outcome is patient's discomfort from the donor site during the first week after the surgery. Secondary outcomes is the time required for suture placement or cyanoacrylate application, patient's pain from donor and recipient site one week post-operatively, painkillers intake, presence or absence of inflammation and modified EHI early-wound healing index.

A prospective, randomized clinical trial will be conducted to determine whether cyanoacrylate tissue adhesives or sutures are better tolerated by patients receiving soft tissue gum grafts.

Periodontal plastic surgery procedures have become an integral part of periodontal treatment by addressing esthetic and functional demands. Several therapeutic modalities such as free gingival graft, pedicle flaps, connective tissue grafts, grafts combining the two lateral modalities and guided tissue regeneration have been used for covering the denuded roots and augmenting the width and thickness of the keratinized gingiva. Among various surgical techniques, subepithelial connective tissue (SECT) grafts remain the most commonly used and most successful root coverage procedures. The esthetic and functional success of SECT graft techniques is highly predictable and reliable and they have given them a common place in the clinical practice. Subepithelial connective tissue graft procedures require harvesting tissue from a donor area, usually the palate. This addition of another surgical site extends the complexity of the procedure and increases patient discomfort.

Single interrupted or continuous interlocking sutures are suggested at the donor site. Suturing is the most common method of wound closure. Other biomaterials such as staples, adhesive tapes, adhesive glues and fibrin sealants have been used generally to hasten the pace of healing. Adhesives interact with different materials, merge and allow them to remain whole. Cyanoacrylates are bio-adhesives that were discovered by Ardis in 1949 and first used for surgery by Coover et al in 1959. When applied to two opposing, wet, living tissue surfaces, they have the ability to cement them in place. Their general chemical formula is CH2=C(CN)-COOR , where R can be substituted for any alkyl group, ranging from methyl to decyl. They polymerize rapidly within seconds in an exothermic reaction following contact with proteinaceous surfaces to form strong and flexible bonds. Methyl cyanoacrylate was the first glue developed, but tissue toxicity precluded its use. The process of causing histologic toxicity is thought to be related to the byproducts of degradation into cyanoacetate and formaldehyde. Further research showed that changing the type of alkyl chains in the compound to one with a longer molecular chain can reduce tissue toxicity. Cyanoacrylates are simple, inexpensive and practical adhesives. Cyanoacrylates have been used for achieving hemostasis at intraoral and extra-oral surgical sites treating ulcers, attaching grafts, managing cerebral spinal fluid leaks, stabilizing the bone fragments during plating, sealing sinus membrane perforations, and achieving peripheral nerve re-anastomosis; as periodontal dressings; and for a number of other dental applications. They are sloughed from the surface of the skin and mucosa 7 to 10 days after adhesive application. Butyl cyanoacrylate is a bacteriostatic, biodegradable, hemostatic cyanoacrylate with a long half-life and good tissue compatibility. It can adhere in moist environments and is available in a formulation appropriate to be used in the oral cavity. It has been proven to be effective in closure of uninfected intraoral incisions on edentulous areas in the mandible, in extractions and periapical surgery.

Few studies are focused on evaluating the wound healing and assessing patient-centered outcomes at the palate donor area after different harvesting techniques To the best of our knowledge, there is no study that compares different methods of wound closure at the donor site.

This prospective clinical trial aims at obtaining information to determine which technique from the patient's standpoint is superior.

The participants will be randomly assigned to one of two groups. The wound closure at the palatal donor area will be achieved with polytetrafluoroethylene (PTFE) sutures in one group and with high viscosity cyanoacrylate tissue adhesives on the other group. The surgical procedure will be performed by one of three calibrated periodontics residents (CS, JB, DR). Patients will be followed for 1 month post-operatively by the same resident to monitor the healing process and obtain patient feedback. Data will be collected at the baseline-day of the surgery, one day post-operatively and at the 1-week follow-up appointment. Randomization will be achieved using a computerized randomization scheme and will be communicated to the surgeon during the surgery by an independent examiner (AC). Participants will be block-randomized for each of the three operators for balance.

Anesthesia will be achieved with greater palatine block anesthesia and local infiltrations, if needed, on the palate with 1.8ml Lidocaine 2% 1:100,000 epinephrine. The single incision harvesting technique is chosen. Following administration for local anesthesia a single incision is made on the anterior hard palatal vault. The length of the incision depends on the size of the graft that is needed.

Once the graft is harvested pressure is applied to the palate until hemostasis is achieved and the graft is maintained in a moist environment.

Using 5-0 PTFE suture, continuous interlocking sutures 4mm apart are placed in the suture group leaving 3-4mm tails. Thin layers of cyanoacrylate are applied and rinsed with saline at least 3 times with interval at least 30s to allow complete polymerization in the cyanoacrylate group until hemostasis is achieved.

The harvested tissue graft is sutured to the donor site. The day of the surgery-a baseline record is obtained (see attached form). A loading dose of Amoxicillin 2g or Clindamycin 600mg, in case of allergy to penicillin, is provided to all participants immediately after the surgery with Ibuprofen 400mg for pain control. Postoperative instructions are also provided. They are also provided with an ice pack for the first 24 hours to minimize swelling from the recipient site. Sufficient amount of Ibuprofen 200mg is provided in a bag for the participants to consume 1-2 tablets po q4-6h PRN. They are instructed to return the bag for recording of the number of painkillers consumed at the 1-week follow-up appointment. A pain visual analogue scale (VAS) questionnaire with no pain on the left site and unbearable pain on the right site is given to the participants to note the level of pain from the palatal site the day after the surgery before the consumption of any painkillers. Participants are encouraged to contact the operator if they have any problem at any time.

Post-operative complications like severe bleeding, infection, abnormal pain, root exposure of the teeth adjacent to the donor site or sloughing, that need to be addressed before the scheduled appointments, will be recorded for 1 month after the surgery.

At the 1-week follow-up appointments the modified early-wound healing index (EHI), the wound length and width, and the presence of normal or abnormal inflammation will be recorded. The number of painkillers consumed the 1st week after the surgery will be counted and recorded. Participants will be asked to report any self-medication for pain. Sutures will be removed in the suture group. A 1-week follow-up VAS questionnaire is given to participants to fill during the 1-week follow-up appointment. The participants are asked to note the level of pain from the donor and recipient site and the level of discomfort (eating, speaking,.) from the donor site during the week after the surgery. Photos will be taken in all appointments.)

Inclusion Criteria:

• Patients of the Graduate Periodontics Clinic, College of Dentistry, University of Manitoba that require harvesting of subepithelial connective tissue graft from the palate from October 2016 to December 2017 and have signed the consent form.

Exclusion Criteria:

• Patients with coagulation disorders (Hemophilia a/b, von Willebrand disease, liver disease, anticoagulative therapy), patients on corticosteroids, patients with uncontrolled diabetes mellitus or with any systematic disease that periodontal surgery is contraindicated, and patient with history of contact dermatitis to formaldehyde will be excluded from the trial.