Dentin hypersensitivity (DH) is defined as short and sharp pain caused by external stimuli such as heat, vaporization, contact, osmotic pressure, and chemical stimulation in a normal tooth, rather than due to disease or tooth damage. Its solution is to block the flow of dentinal fluid by physically blocking the dentinal tubule. Of these treatments, fluoride and oxalate type for hypersensitivity can only have a temporary effect. Resins should be used with a suitable bonding system and they may cause hypersensitivity symptoms after treatment. Overcoming these limitations, there is a need for method that can effectively treat dental hypersensitivity lasting long without any side effects. For this reason, experiments with 200 plant extracts as candidates for dentin hypersensitivity, Buddleja officinalis was considered as a candidate for present study. The purpose of this study is to confirm whether the ethanol extract of Buddleja officinalis is effective to protect enamel and dentin by coating tooth surface and resistance to acid or alkali even after tooth coating.

The flowers of Buddleja officinalis are used to treat sore and damaged eyes, a condition which is similar to skin wounds. However, whether it has any protective effect on oxidative DNA damage and cell death induced by hydroxyl radical remains unclear. In this study, we evaluated the protective effects of the extracts against oxidative DNA and cell damage caused by hydroxyl radical. DPPH radical, hydroxyl radical, hydrogen peroxide and intracellular ROS scavenging assay, and Fe2+ chelating assay were used to evaluate the antioxidant properties. phi X 174 RF I plasmid DNA and intracellular DNA migration assay were used to evaluate the protective effect against oxidative DNA damage. Lastly, MTT assay and lipid peroxidation assay were used to evaluate the protective effect against oxidative cell damage. It was found to prevent intracellular DNA and the normal cells from oxidative damage caused by hydroxyl radical via antioxidant activities. These results suggest that Buddleja officinalis may exert the inhibitory effect on ROS-induced carcinogenesis by blocking oxidative DNA damage and cell death.