A comparative study of conventional and Hall techniques of crown placement using finite element stress analysis.

Background: Hall technique of crown placement causes the changes in vertical occlusal dimension; the mode of settlement of which needs to be explored.

Aim: To assess and compare the changing patterns of stress distribution following placement of stainless steel crowns on primary teeth by Hall and conventional techniques using a finite element model analysis.

Materials and methods: The clinical crown heights of primary molars restored with Hall and conventional techniques and opposing teeth in contact, vertical dimension changes in the primary canine area were measured using intraoral digital scan. T-scan was used to measure the changes in bite force while the finite element analysis was used to assess deformative changes on the 2^nd, 5^th, 10^th, and 15^th days.

Results: The Hall technique of crown placement caused more stress distribution in the tooth supporting tissues that settled in 2 weeks as compared with conventional technique of crown placement in which settlement occurred in 2 days.

Conclusion: The settling of vertical occlusal dimension as well as stress distribution in Hall technique probably takes place by intrusion of crowned tooth and opposing teeth in contact.