1903 Charles Land devises the porcelain jacket crown.
1905 Alfred Einhorn, a German chemist, formulates the local anesthetic procain, later marketed under the trade name Novocain.
1907 William Taggart invents a “lost wax” casting machine, allowing dentists to make precision cast fillings.
1908 Greene Vardiman Black, the leading reformer and educator of American dentistry, publishes his monumental two-volume treatise Operative Dentistry, which remains the essential clinical dental text for fifty years.
1913 Alfred C. Fones opens the Fones Clinic For Dental Hygienists in Bridgeport, Connecticut, the world’s first oral hygiene school. Most of the twenty-seven women graduates of the first class are employed by the Bridgeport Board of Education to clean the teeth of school children. The greatly reduced incidence of caries among these children gives impetus to the dental hygienist movement. Dr. Fones, first to use the term “dental hygienist,” becomes known as the Father of Dental Hygiene.
1917 Irene Newman receives the world’s first dental hygiene license in Connecticut.
1938 The nylon toothbrush, the first made with synthetic bristles, appears on the market.
1945 The water fluoridation era begins when the cities of Newburgh, New York, and Grand Rapids, Michigan, add sodium fluoride to their public water systems.
1949 Oskar Hagger, a Swiss chemist, develops the first system of bonding acrylic resin to dentin.
1950 The first fluoride toothpastes are marketed.
1955 Michael Buonocore describes the acid etch technique, a simple method of increasing the adhesion of acrylic fillings to enamel.
1957 John Borden introduces a high-speed air-driven contra-angle handpiece. The Airotor obtains speeds up to 300,000 rotations per minute and is an immediate commercial success, launching a new era of high-speed dentistry.