Y Zeng1, J Wang, S Zhou. 1. School of Stomatology, Beijing Medical University, Beijing 100081, China.
Abstract
OBJECTIVE: To study the induction of vertical root split by occlusal force. METHODS: 1. The occlusal contact force was studied in 34 cases (39 teeth) by photocclusion. 2. The stress analysis for the first mandicular molar was studied by three-dimensional definite element. RESULTS: 1. The occlusal contact force didn't distribute balancedly in 26 cases (31 teeth) and the suffering teeth bore greater force. 2. The bucco-lingual central line of the mesial root canal wall underwent greater tensile stress when tooth bore load with 30 degrees angle to axis, or buccal-lingual lateral load or logitudinal occlusive load on the masial or distal cusp. CONCLUSION: The vertical root split of molar is associated with greater occlusal force and the stress that concentrated on the buccolingual central line of the mesial root wall for a long time.
OBJECTIVE: To study the induction of vertical root split by occlusal force. METHODS: 1. The occlusal contact force was studied in 34 cases (39 teeth) by photocclusion. 2. The stress analysis for the first mandicular molar was studied by three-dimensional definite element. RESULTS: 1. The occlusal contact force didn't distribute balancedly in 26 cases (31 teeth) and the suffering teeth bore greater force. 2. The bucco-lingual central line of the mesial root canal wall underwent greater tensile stress when tooth bore load with 30 degrees angle to axis, or buccal-lingual lateral load or logitudinal occlusive load on the masial or distal cusp. CONCLUSION: The vertical root split of molar is associated with greater occlusal force and the stress that concentrated on the buccolingual central line of the mesial root wall for a long time.