Objective: To evaluate the effectiveness of a gel containing nanovitamin C, nanovitamin E and propolis extract compared to a placebo in the treatment of desquamative gingivitis (GD) in patients with mucocutaneous diseases with gingival involvement. The possible improvement in the quality of life of these patients after treatment will also be evaluated.

Study design: Double-blind, randomized controlled study.

Patients: GD patients are being selected from the Postgraduate 'Specialist in Oral Medicine' of the Faculty of Dentistry, Complutense University of Madrid.

Allocation: Patients are being randomly assigned to the study group (dental prophylaxis + oral hygiene instructions + use of propolis gel for 4 weeks) or to the placebo group (dental prophylaxis + oral hygiene instructions + use of placebo gel for 4 weeks ). Both the study gel and the placebo are being used for brushing their teeth and for application in areas with GD.

Variables: The severity of the GD will be collected according to the scale of Arduino et al. 2017 and the periodontal variables (plaque index, probing bleeding index and probing depth). Pain during treatment will be recorded using a 10 cm visual analog scale (VAS). The quality of life in relation to oral health will be recorded using the Oral Health Impact Profile-14 (OHIP-14) questionnaire. These variables will be collected on day 0, 2 and 4 weeks after using the study gel or placebo.

Inclusion Criteria:

1. Patients over 18 years of age.
2. Patients with a clinical and histological diagnosis of some mucocutaneous disease. Patients diagnosed with oral lichen planus will be selected according to the American Academy of Oral and Maxillofacial Pathology, pemphigus vulgaris and / or scarring pemphigoid according to the 2015 World Workshop on Oral Medicine.
3. Patients who present GD, that is, erythema, epithelial desquamation, atrophy, painful erosions or ulceration of the free and / or attached gingiva, which is not related to the local accumulation of plaque.

Exclusion Criteria:

1. Being in cancer treatment with head and neck radiotherapy, chemotherapy or immunotherapy.
2. Being diabetic.
3. Being on topical corticosteroid treatment in the previous 4 weeks or systemic treatment in the previous 8 weeks.
4. Those patients who do not present the anterosuperior sector (from canine to upper canine) or the anteroinferior sector (from canine to lower canine) will also be excluded.
5. Pregnant or breastfeeding.
6. Being a smoker.
7. Use of rinses for plaque control.
8. Being medicated with drugs associated with gingival enlargement such as cyclosporine, calcium channel blockers and phenytoin.
9. To have taken antibiotics and / or anti-inflammatories 3 months before the study.
10. Taking medications capable of producing lichenoid reactions.
11. Patients who do not want to sign the informed consent.
12. Patients with periodontitis according to the consensus criteria of Papapanou et al. 2018 or patients treated for unstable periodontal disease according to the classification of Chapple et al. 2017.

We will try to publish it as a scientific article