Dentsply Sirona, Inc, made several leadership changes today. Effective immediately, CEO Jeffrey Slovin, Executive Chairman Bret Wise, and President and COO Christopher Clark have all resigned. The company named Mark A. Thierer as interim CEO and Bob Size as interim president and COO. Eric K. Brandt was elected as non-executive chairman of the board. The board of directors has also initiated a search process to identify a permanent CEO and COO.