Dr. Seibert contributed to numerous textbooks and wrote many articles during his career.
Before joining the dental school, he served in the Army Dental Corps for 20 years and retired as a full colonel in 1973 from Walter Reed Army Medical Center in Washington.
He was born in Livingston, N.J., raised in nearby West Orange, and graduated from West Orange High School.
After completing his pre-med studies at Bucknell University in Lewisburg, Pa., he graduated from Penn Dental School in 1953 and completed training in periodontology in 1960 at Baylor University Dental School in Dallas, Texas.
Dr. Seibert had lived in Devon for 24 years and was a member of St. Monica Roman Catholic Church in Berwyn.
His professional memberships included the American Dental Association, the American Academy of Periodontology and the Pennsylvania Society of Periodontology. He was a diplomate of the American Board of Periodontology.
He is survived by his wife of 46 years, Joan Marie Reid Seibert; children John, Kimberly, Valerie, Thomas and Jeffrey; a brother; a sister; and a grandson.
A Funeral Mass will be celebrated at 10 a.m. today at St. Monica Church, Berwyn. Burial will be in the church cemetery.
The family suggests memorial contributions to St. Monica Church, 635 First Ave., Berwyn, Pa. 19312.