Please select the eligibility criteria that correspond to the clinical trial below.
Title: Clinical Comparison Between Two Surgical Techniques With Acellular Dermal Matrix Graft in the Treatment of Gingival Recessions
Brief Summary: The aim of this study is to test a surgical technique for the treatment of gingival recessions. The hypothesis of the study is to promote greater root coverage and better healing.


Options:
A: Inclusion Criteria:

1. presenting Miller class I or II gingival recession in the maxillary canines or premolars;
2. visible cemento-enamel junction (CEJ) in the teeth included in the study and pulp vitality;
3. patients presenting no signs of active periodontal disease and full-mouth plaque and bleeding score ≤ 20%;
4. patients older than 18 years old;
5. probing depth ˂ 3 mm in the included teeth; 6) patients who agreed to participate and signed an informed consent form

Exclusion Criteria:

1. patients with systemic problems (cardiovascular, blood dyscrasias, immunodeficiency, and diabetes, among others) that will contraindicate the surgical procedure
2. patients taking medications known to interfere with the wound healing process or that contraindicate the surgical procedure
3. smokers or pregnant women
4. patients who underwent periodontal surgery in the area of interest; and 5) patients with orthodontic therapy in progress.
B: Inclusion Criteria:

* Recession defects are Miller's class I or II and do not vary more or equal than 3 mm
* Main complaint aesthetic issues or dentine hypersensitivity
* The patient must be a candidate for bilateral root coverage procedure
* Patient shows sufficient plaque control (FMPS \< 20%)
* The patient is able to comply with the study-related procedures such as exercising good oral hygiene and attending all follow-up procedures
* The patient is able to fully understand the nature of the proposed surgery and is able to provide a signed informed consent

Exclusion Criteria:

* Smokers
* Systemic diseases
* Pregnants or lactating
* Periodontal disease
* General contraindications for dental and/or surgical treatment are present
* The patient has a history of malignancy, radiotherapy, or chemotherapy for malignancy within the past five years
* The patient is taking medications or having treatments which have an effect on mucosal healing in general (e.g. steroids, large doses of anti-inflammatory drugs)
C: Inclusion Criteria:

* Age ≥ 18 years.
* Presence of at least one Class I or II Miller gingival recession ≥ 2.5 mm in maxillary canines or premolars with identifiable cementum-enamel junction (CEJ) and without deep non-carious cervical lesions (\< 0.5 mm): A +(Pini-Prato et al. 2010).
* Aesthetic complaint and/or presence of dentin hypersensitivity to air stimulus.
* Full-mouth visible plaque index ≤ 20% (Ainamo \& Bay 1975).
* Full-mouth sulcus bleeding index ≤ 20% (Mühlemann \& Son 1971).

Exclusion Criteria:

* Smoking.
* Pregnancy.
* Presence of systemic disorders (diabetes, hypertension, heart disease or any other condition that could contraindicate periodontal surgery).
* Use of medications (immunosuppressants, phenytoin or anything else that might affect mucosal healing and repair).
* Previous periodontal surgery in the area.
D: Inclusion Criteria:

* The patient (male or female) must be 18 years or older
* The patient must be a candidate for bilateral root coverage procedure
* Recession defects are Miller Class I-II and do not vary more than 2 mm.
* At least one mm keratinized tissue is present.
* Patient shows sufficient plaque control (FMPS \< 20%).
* If patient is of child-bearing potential, the patient confirms not to be pregnant and agrees to take contraception for at least 6 months after surgery.
* The patient is able to comply with the study-related procedures such as exercising good oral hygiene and attending all follow-up procedures
* The patient is able to fully understand the nature of the proposed surgery and is able to provide a signed informed consent.

Exclusion Criteria:

* Patient is a heavy smoker (\> 10 cigarettes per day)
* Patient is an insulin dependent diabetic
* General contraindications for dental and/or surgical treatment are present.
* The patient has a history of malignancy, radiotherapy, or chemotherapy for malignancy within the past five years.
* The patient is pregnant or nursing
* The patient is taking medications or having treatments which have an effect on mucosal healing in general (e.g. steroids, large doses of anti-inflammatory drugs).
* The patient has a disease, which affects connective tissue metabolism (e.g. collagenases).
* The patient is allergic to collagen.
* Patients have participated in a clinical trial within the last six months.

Answer: B