Ultraviolet (UV) Activation Effect on Antibacterial Agents of Red Betel (Piper Crocatum) Extract to Streptococcus mutans

Ultraviolet (UV) radiation has caused negative effect on biological environment. As non-moving living things, plants have their own response to reduce the negative effect by increasing flavonoid accumulation, such as red betel (Piper crocatum), which help the plant's protection from bacteria. In Indonesia, red betel has been used as a herb treatment, especially in oral treatment. This study aims to optimise the antibacterial effect of red betel extract on oral bacteria, Streptococcus mutans, by irradiating UV. Kirby-Bauer method of disk diffusion test was used on this study by showing the bacteria's diameter of inhibition zone. The samples distribution was devided into two groups, group (L-R+), control group, only used red betel extract without UV irradiation and group (L+R+) treatment combination of UV irradiation and red betel extract. The results showed that group L+R+ had better antibacterial effect on Streptococcus mutans, proven by the bigger inhibition zone, than group L-R+. UV irradiation for 12 hours showed the best result on each treatment with diameter of inhibition zone (15.00 ± 0.05) mm for 10 watt and (15.96 ± 0.05) mm for 15 watt. So, it is proven that UV irradiation can increase the antibacterial effect of red betel extract.