Xenogeneic Collagen Matrix or Palatal Connective Tissue Graft With a Coronally Advanced Flap in Class III Recessions

The purpose of this multi-center study is to compare the effectiveness of Mucograft versus connective tissue graft in combination with coronal advanced flap for the treatment of Miller class III recessions The connective tissue graft in combination with coronal advanced flap is considered the gold standard for the treatment of gingival recession in terms of percentage of root coverage and complete root coverage. However connective tissue graft harvesting from the palatal mucosa is often associated with increased patient morbidity, prolonged surgical time and is limited supply. To overcome these inconvenients many efforts are made to develop new materials (healing modifiers, barrier membranes and grafts substitutes) Recently a new two-layer , xenogenic collagen matrix (Mucograft: Geistlich Pharma , Wolhusen Switzerland) has been proposed for regenerative therapy involving teeth and implants. The use of this porcine collagen matrix has obtained promising results for treatment of Miller class I and II recession defects (isolated and multiple recession defects) The mayority of root coverage studies in the literature treats Miller class I and II recession defects .Surgical treatment of class III recesión defects is more challenging due to loss of interproximal bone and soft tissues and complete root coverage may not be expected . But some recent studies demonstrate complete root coverage and high percentage of root coverage in class III recessions. Also a new classification system using the level of interproximal attachment level has been proposed to predict the final root coverage outcome.

So ,the soft tissue substitutes should be used also in Miller class III recession, and because of that fact, the investigators are conducting this study, to evaluate the effectiveness of Mucograft in Miller class III recessions compared with connective tissue graft.

Given data reported by the study of Aroca in 2013 ,using the percentage of root coverage as a primary response variable the sample size was estimated in 20 patients. In addition, taking into account possible drop-outs, the investigators would increase the number of patients by 20%, finally recruiting 24 patients per group.

Randomization was performed by computer generated random codes Study locations will include two private centers in Spain. A single calibrated examiner, blind with respect to the treatment assignment, will perform all measurements at all center.

A biostatistician blind with respect to treatment assignment will perform the analysis.

Interventions and Duration The two intervention groups will consist of surgery with connective tissue graft (standard of care control) and surgery with the application of Mucograft Collagen Matrix (MCM, Test group). Experienced clinicians will deliver treatment consisting of root coverage surgery using coronally advanced flaps, the most utilized procedure for coverage of recessions. Surgery will be standardized and the same procedures/materials will be employed to ensure consistency.

Follow-up of individual patients will be 12 months.

Eligibility Criteria:
Inclusion Criteria:

* The patient must be 18 years or older
* Patient with one or more recession defects are Miller Class III in incisives, canines and premolars. In at least two quadrants
* Patient shows sufficient plaque control (FMPS \< 20%).
* Treated periodontal conditions
* The patient is able to fully understand the nature of the proposed surgery and is able to provide a signed informed consent.

Exclusion Criteria:

* General contraindications for dental and/or surgical treatment are present.
* 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).
* Untreated periodontal conditions
* Patients not willing to participate