A randomized, crossover, double-blind, placebo-controlled, one-session clinical trial with 30 male volunteers was performed to access pain and safety of microneedle topical application in different regions of the oral cavity.

A randomized, crossover, double-blind, placebo-controlled, one-session clinical trial with 30 male volunteers was performed by applying a microneedle patch in the following regions of the oral cavity: lip (inner lower), buccal (cheek: 1 cm behind the month angle), tongue (dorsal surface), hard palate (anterior region), and attached gingiva (between central and lateral upper incisors). A 30 gauge hypodermic needle and an identical patch but without microneedles sticking out, were used as positive and negative controls, respectively. The application force was standardized to 10N by an applicator composed of a 5 mL syringe and a spring. Insertions were performed with a gap of 30 seconds. Pain and discomfort associated to the procedure was evaluated with a Visual Analogue Scale (VAS), by a blinded-dentist. The safety associated to microneedle application was verified immediately after the application (0h) and after the next day (24h). The different application sites were inspected visually for bleeding, ulceration, bruising, redness or swelling.

Inclusion Criteria:

- Healthy male

Exclusion Criteria:

- Volunteers were free from cardiac, hepatic, renal, pulmonary, neurological, gastrointestinal and haematological diseases, psychiatric disorders, smokers or alcoholic.