Novel approach to assessing the primary stability of dental implants under functional cyclic loading in vitro : a biomechanical pilot study using synthetic bone

This pilot study was conducted to develop a novel test setup for the assessment of the primary stability of dental implants. This was achieved by characterising their long-term behaviour based on the continuous recording of micromotions resulting from dynamic and cyclic loading. Twenty screw implants, each 11 mm in length and either 3.8 mm (for premolars) or 4.3 mm (for molars) in diameter, were inserted into the posterior region of 5 synthetic mandibular models. Physiological masticatory loads were simulated by superimposing cyclic buccal-lingual movement of the mandible with a vertically applied masticatory force. Using an optical 3-dimensional (3D) measuring system, the micromotions of the dental crowns relative to the alveolar bone resulting from alternating off-centre loads were concurrently determined over 10,000 test cycles. The buccal-lingual deflections of the dental crowns significantly increased from cycle 10 to cycle 10,000 (