BALTIMORE -- The University of Maryland College of Dental Surgery celebrates its 150th anniversary this week, marking its place in history as the oldest dental school in the world and one with an institutional memory to match.

It has seen dentistry grow from the primitive trade of barbers, blacksmiths and assorted quacks of mid-19th century America to the highly skilled, specialized and often lucrative profession that it is today.

It has seen the evolution of cavity-drilling instruments from the hand chisels and excavators of the Civil War era to foot-driven drills introduced in 1882 to the high-speed air turbine drills of today. It has witnessed the change in cavity-filling material from metals to plastics and seen the development of anesthesia from nitrous oxide gas (so-called laughing gas) in 1844 and ether in 1846 to the exotic local anesthetics of today, such as xylocaine , injected for routine fillings.

"Before anesthesia," said Errol L. Reese, dean of the dental school here, "you had to take a drink of whiskey and just scream and shout."

There have been "profound changes" in dentistry since then, Reese said in an interview, "and we like to think we had a leading part in that process."

Since the day it opened its doors to five students on Nov. 3, 1840, the school has graduated more than 10,000 dentists and offered an ever-increasing array of specialized training.

Today, more than 600 students are enrolled in the three-year dental school or in related graduate and postgraduate programs.

Set in the University of Maryland's graduate schools complex just west of downtown Baltimore, the dental school operates a clinic that logs more than 100,000 visits a year by indigent and elderly patients receiving treatment from students.

According to dental historian Garner P.H. Foley, the school was founded by a group of prominent self-taught dentists led by Horace H. Hayden, of Windsor, Conn., and Chapin A. Harris, of New York City, who wanted to professionalize the work done up until then by largely "unlettered and untrained men."

Following in the footsteps of medical schools, Hayden, Harris and others also established a dental society and dental journal, creating "the tripod . . . necessary to elevate dentistry from a not respectable trade to an acceptable and honorable profession," Foley said.

Baltimore was selected for the new school, he said, because of its convenience to both the North and South and for its port, making it accessible to students from distant U.S. cities as well as abroad.

According to Foley, the college graduated 328 students between 1840 and the outbreak of the Civil War in 1861. Of those, 208 were from Maryland and southern states, 98 from northern states and 22 from other nations, including England, Germany, Ireland and Switzerland.

The school now houses a dental museum, the first of its kind in the world, according to school officials. Among its artifacts is a set of lower dentures made in the 1790s for George Washington.

Designed by New York dentist John Greenwood, they were made from hippopotamus ivory, not wood, as often thought. The upper portion of the dentures, containing a large section of gold, was stolen in 1981.

The first woman graduated from the school in 1873 and the first black almost 100 years later in 1972. Current enrollment is 48 percent female and 27 percent minority, according to school figures.

Enrollment has fluctuated widely. During the 1850s, there were 40 to 50 students to a class, but the number fell precipitously during the Civil War, then returned to previous levels.

In modern times, the numbers soared into the hundreds, but a nationwide glut of dentists in the 1970s caused several dental schools, including Maryland's, to cut back on freshman admissions. Five of the nation's then 60 dental schools closed.

Maryland dental association officials blamed the glut on two factors: the widespread use of tooth-preserving fluoride and greatly intensified office procedures in which a dentist and two or three assistants work on several patients simultaneously, replacing the traditional practice of seeing one patient at a time.

After a survey of the state's dental needs in 1978, the school began reducing freshman enrollment from 138 to its present level of 96. Reese says the number will stay at that level for at least the next decade.