Complications Related to Palatal Graft Harvesting

Soft tissue defects can be a problem, especially in patients with high smile lines; in these clinical scenarios, the treatment with periodontal plastic surgery in combination with the use of a connective tissue graft (CTG) is considered the gold-standard procedure.

Single incision technique (Huerzeler \& Weng, 1999) is one of the suggested procedures to harvest the CTG from palate. The UPV/EHU technique (Aguirre-Zorzano et al, 2017) showed less inflammation and post-surgical complications than trap-door technique, but also other technique should to be analysed.

However, there is still no consensus about which is the best technique to obtain this kind of graft. Therefore, clinicians should justify their choice based on the tissue's quality obtained and the patient's well-being, producing the least number of complications, such as inflammation, post-surgical pain, or recession in the donor area.

HYPOTHESIS:

Does the technique of obtaining an CTG of the palate using the "UPV/EHU technique" (Aguirre-Zorzano et al., 2017) result in a lower number of complications versus the "single incision technique" (Huerzeler \& Weng, 1999)?

OBJECTIVES The main objective is to assess whether the complications occurring with the harvesting of the CTG using the "UPV/EHU technique" (Aguirre-Zorzano et al., 2017) are lower than with the "single incision technique"(Huerzeler \& Weng, 1999), knowing the patient's perception of pain.

The secondary objectives are: a) necrosis of the palate, b) possible resulting recession in the donor area, and c) characteristics of the graft obtained

Type of Study: randomized clinical trial

Two different treatments (UPV/EHU technique (test) (Aguirre-Zorzano et al. 2017) vs. Single Incision technique (control) (Huerzeler \& Weng, 1999)) will be compared. These techniques are usually used to harvest a CTG from the palate.

Main outcome: complications in the donor area.

Follow-up: 6 months.

UNIT OF ANALYSIS: The patient of the Master's Degree in Periodontology and Osseointegration from the University of the Basque Country (UPV/EHU), requires treatment with a CTG harvested from the palate.

SAMPLE SIZE CALCULATION: Using the visual analog pain scale (VAS pain) as the primary response variable, it is estimated that, to find a difference of 1 between test and control, with an SD= 1.26 (Wessel \& Tatakis 2008), an alpha risk of 5% and a power of 85%, we would need 29 patients for each treatment group (Domenech and Granero 2010). In addition, taking into account possible dropouts, we would increase the number of patients by 20%, finally recruiting 35 patients per group.

Statistical analysis:

A descriptive study of the sample will be performed, based on moments (mean, standard deviation) if the parameters of normality are met or on ordinations (median and interquartile range), in case the parameters of normality are not met.

Subsequently, analytical statistics will be performed, and in addition, the intensity and duration of post-surgical pain after each surgical technique adjusted for possible confounding factors (clinical level of central sensitization, presence of pre-surgical pain, presence of post-surgical complications, use of added analgesic treatment) will be assessed using logistic regression.

Eligibility Criteria:
Inclusion Criteria:

* Patients of the UPV/EHU university dental clinic who required a connective graft of the palate in their treatment.
* Patients ≥ 18 years-old
* Absence of active periodontal disease ( healthy periodontal patients or periodontal patients who had received active periodontal treatment, and now they are included in a tailored supportive periodontal program)
* Full-mouth plaque index (FMPI) (O'Leary y cols. 1972) and full-mouth bleeding index (FMBI) (Ainamo y Bay, 1975) ≤ 25%

Exclusion Criteria:

* Smokers of ≥ 10 cigarettes/day
* Systemic conditions that contraindicated surgery
* The use of analgesic and/or anti-inflammatory drugs in the last 72 h
* The use of opioid drugs, anticonvulsants and/or antidepressants, except selective serotonin inhibitors, i.e., those drugs that act by reducing the painful experience
* Pregnancy or nursing women