Harinakano Family Dentistry, Japan.
Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, Japan.
J Prosthodont Res. 2020 Oct;64(4):454-459. doi: 10.1016/j.jpor.2019.12.004. Epub 2020 Feb 13.
The purpose of this study was to determine the influence of mandibular free-end partial edentulism and the wearing of removable partial dentures in the partially edentulous area on the force exerted on maxillary anterior teeth.
A commercially available jaw model with exchangeable teeth was used. Seven experimental conditions of mandibular free-end edentulism were set up and a distal extension removable partial denture to replace missing posterior teeth was fabricated. Strain gauges were attached to the root surface of the maxillary left central incisor, canine, first premolar and first molar, and the force exerted on them was calculated based on the calibration coefficient. An occlusal load of 49 N was applied and the forces were compared with the Kruskal-Wallis test (P < 0.05).
The force exerted on the maxillary anterior teeth increased significantly as the number of remaining teeth decreased. The force exerted on the maxillary anterior teeth decreased significantly with use of a removable partial denture.
When the number of remaining teeth decreases in mandibular free-end partial edentulism, the burden on the maxillary anterior teeth increases. Our findings suggest that for patients with mandibular free-end partial edentulism, wearing a removable partial denture is effective in preserving the remaining teeth by reducing excessive stress.
本研究旨在确定下颌游离端部分牙列缺失以及可摘局部义齿在部分缺牙区的佩戴对上颌前牙所受力的影响。
使用带有可更换牙齿的市售颌模型，设置了 7 种下颌游离端无牙颌的实验条件，并制作了一个远中游离端可摘局部义齿来替代缺失的后牙。将应变片贴附在上颌左中切牙、尖牙、第一前磨牙和第一磨牙的根表面，根据校准系数计算它们所受的力。施加 49N 的咬合负荷，并使用 Kruskal-Wallis 检验（P<0.05）进行比较。
随着剩余牙齿数量的减少，上颌前牙所受力显著增加。使用可摘局部义齿后，上颌前牙所受力显著减小。
当下颌游离端部分牙列缺失时，剩余牙齿数量减少，上颌前牙的负担增加。我们的研究结果表明，对于下颌游离端部分牙列缺失的患者，佩戴可摘局部义齿可通过减少过度的应力来有效保护剩余牙齿。
