3% Hydrogen Peroxide safe as a mouthwash?

Is using 3% Hydrogen Peroxide as a mouthwash twice a day after flossing and brushing safe for the gums and teeth?

I ask because of posts such as this one from a Google search on the question.

"research shows that it (Hydrogen Peroxide) can penetrate the tooth enamel and dentin and reach the very inner tooth chamber called dental pulp. Hydrogen peroxide has low molecular weight and the ability to destroy proteins, which facilitate diffusion through enamel and dentin. The dental pulp is where the blood vessels and nerves of each tooth reside, which makes this area particularly sensitive. A unique class of cells, called odontoblasts also reside in the periphery of the dental pulp area, which support the teeth by depositing new dentin layers throughout life and are also believed to play a protective/reparative role in response to dental carries or other environmental factors that harm teeth. The problem with hydrogen peroxide is that it has a cytotoxic effect on the dental pulp cells, which means that it literally kills them. A study published in 2013 in the Journal of Endodontics shows that even low concentrations of hydrogen peroxide trigger molecular mechanisms in pulp cells, which activate programmed cell death." Tweet