Kaplony, son of a professional officer, came to Switzerland in December 1944. He became a Swiss citizen in 1958. He studied Ancient History, Egyptology, Arabic language and Arabic literature in the University of Zurich and University of Basel. In 1959, he was awarded PhD in Zurich and, in 1964, his Habilitation. From 1970 until his retirement in 2000, he was assistant professor and then professor emeritus of Egyptology at the Oriental Institute of the University of Zurich. He was especially working on the pre-dynastic and early dynastic periods of Egypt and published mostly in German and Swiss research journals.
- The Egyptian inscriptions of the early days. 4 volumes, Harrassowitz, Wiesbaden from 1963 to 1964
- The cylinder seals of the Old Kingdom. La Fondation Reine Élisabeth Égyptologique, Brussels 1981