The purpose of this study is to determine whether oral topic silver nanoparticles are effective to reduce potential pathogen microbial loads in mechanical ventilation patients.

All patients were performed with oral hygiene as recommended by the clinical practice guidelines for the prevention, diagnosis and treatment of pneumonia associated with mechanical ventilation. After that, placed the treatment of an innocuous gel compound with 12ppm of silver nanoparticles or gel alone according to randomization. Then obtain and plant samples taken before the treatment 6 hours after. Comparing the results of the baseline sample with the final.

Inclusion Criteria:

1. Patients with at least 24 hrs application endotracheal tube and ventilator support were nasogastric tube ,in the ICU of Hospital Central "Dr. Ignacio Morones Prieto"
2. Patients with at least 24 hours of ICU admission.
3. Sedo - analgesia patients in a coma or induced coma.
4. Over 15 years old
5. Informed consent signed by a family member or legal guardian of the patient.

Exclusion Criteria:

1. The patient is not taking part in another study that cause conflict with the present test.
2. Patients who develop bronchiectasis , severe or massive hemoptysis , cystic fibrosis.
3. Patients with known sensitivity to silver.
4. Patients who had reported difficult intubation in the record.
5. Patients whose physical condition does not allow the completion of the oral examination, proper sampling or application of gel.
6. Pregnant women
7. Patients with oral mucositis

in process