Potensi Ekstrak Etanol Rimpang Rumput Teki (Cyperus rotundus L.) Sebagai Agen Antimikrobial Terhadap Bakteri A. Actinomycetemcomitans (ATCC 29522) dan P. Gingivalis (ATCC 33277) In Vitro = Potency of Ethanol Extract of Nutgrass (Cyperus rotundus L.) Rhizome as an Antimicrobial Agent Against A. Actinomycetemcomitans (ATCC 29522) and P. Gingivalis (ATCC 33277) In Vitro