Department of Restorative Dentistry. R. Dr. José Rocha Junqueira, São Leopoldo Mandic Dental Research Center, 13 - Pte. Preta, Campinas, SP, 13045-755, Brazil.
J Mater Sci Mater Med. 2020 Apr 11;31(4):39. doi: 10.1007/s10856-020-06377-7.
Assess, using finite element analysis, the adhesive behavior of Class I restorations under physiological occlusal loads on an endodontically treated first upper premolar with conventional and conservative crown opening surrounded by alveolar bone in normal and osteoporotic conditions. For this, four virtual models were used: M1-conservative access/normal bone; M2-conventional access/normal bone; M3-conservative access/osteoporotic bone; M4-conventional access/osteoporotic bone. On enamel, under axial load, the highest peaks occurred on conventional models and, under oblique load, the highest peaks occurred on conservative opening models. The bone condition showed no influence on the adhesive behavior. On dentin, under axial load, the models showed similar behaviors, regardless of the bone condition; under oblique load, the highest incidence of forces occurred on the distal region of the palatal root canal entrance and the highest peak was observed in the conventional opening model with normal bone. Also, under oblique load, conventional opening models showed larger values on dentin for the normal bone and similar for the osteoporotic. The conclusions shows higher displacement tensile strength peaks were observed in the conventional models, which can lead to a greater risk of adhesive failure on class I restorations with this opening. Therefore, a conservative opening would be recommended to avoid opening clinical complications. The bone condition showed no significant influence on adhesive behavior, except for dentin under oblique load, where conventional models showed larger values relative to normal bone and similar to the osteoporotic bone.
采用有限元分析评估在生理咬合载荷下，第一上颌前磨牙经牙髓治疗后，用传统和保守的冠部开口，并用牙槽骨环绕，在正常和骨质疏松条件下的Ⅰ类修复体的粘结行为。为此，使用了四个虚拟模型：M1-保守入口/正常骨；M2-常规入口/正常骨；M3-保守入口/骨质疏松骨；M4-常规入口/骨质疏松骨。在釉质上，轴向载荷下，传统模型的峰值最高，斜向载荷下，保守开口模型的峰值最高。骨条件对粘结行为没有影响。在牙本质上，轴向载荷下，无论骨条件如何，模型的行为都相似；斜向载荷下，腭根管入口的远中区域出现的力最大，且在正常骨的常规开口模型中观察到的峰值最高。此外，在斜向载荷下，正常骨的传统开口模型显示出更高的牙本质值，而骨质疏松骨的传统开口模型则相似。研究结果表明，常规模型观察到更高的拉伸强度峰值，这可能导致这种开口的Ⅰ类修复体发生粘结失败的风险更大。因此，为了避免临床并发症，建议采用保守开口。骨条件对粘结行为没有显著影响，除了斜向载荷下的牙本质，其中常规模型显示出相对于正常骨更高的值，与骨质疏松骨相似。
