[Contribution of vibration supported cementation on reconstructions]

A laboratory study was undertaken to investigate the influence of different types of cement and cementation techniques on the enlargement of the marginal gap of crowns. The crowns and preparations in the study were standardized; preparation forms were shoulder, chamfer and shoulderless. The cement brands were Harvard, Durelon and AquaCem. The enlargement of the marginal gap was measured for two different cementation methods: 1. Crowns were manually seated onto metal dies and subsequently loaded with 50 N constantly for 10 minutes 2. Crowns were manually seated on the dies and exposed to mechanical vibration from a Bergendal amalgam-condenser, subsequently loaded with 50 N constantly for 10 minutes. The comparison of both methods showed a 12-31% smaller vertical cementation gap enlargement of the samples that were treated with vibration. We recommend the clinical use of this method. Best results were achieved with AquaCem; Harvard showed the greatest difference when changing between the methods.