Ricucci Domenico, Siqueira José F, Loghin Simona, Lin Louis M
Private Practice, Cetraro, Italy.
Department of Endodontics, Faculty of Dentistry, Estácio de Sá University, Rio de Janeiro, RJ, Brazil.
J Dent. 2017 Jan;56:19-32. doi: 10.1016/j.jdent.2016.10.005. Epub 2016 Oct 12.
Descriptions of the pathologic changes in the pulp and associated apical structures of human immature teeth in response to deep caries are lacking in the literature.
This article describes the histologic events associated with the radicular pulp and the apical tissues of human immature teeth following pulp inflammation and necrosis.
Twelve immature teeth with destructive caries lesions were obtained from 8 patients. Two intact immature teeth served as controls. Teeth were extracted for reasons not related to this study and immediately processed for histopathologic and histobacteriologic analyses. Serial sections were examined for the pulp conditions and classified as reversible or irreversible pulp inflammation, or pulp necrosis. Other histologic parameters were also evaluated.
In the 3 cases with reversible pulp inflammation, tissue in the pulp chamber showed mild to moderate inflammation and tertiary dentin formation related to tubules involved in the caries process. Overall, the radicular pulp tissue, apical papilla and Hertwig's epithelial root sheath (HERS) exhibited characteristics of normality. In the 3 cases with irreversible pulp inflammation, the pulps were exposed and severe inflammation occurred in the pulp chamber, with minor areas of necrosis and infection. Large areas of the canal walls were free from odontoblasts and lined by an atubular mineralized tissue. The apical papilla showed extremely reduced cellularity or lack of cells and HERS was discontinuous or absent. In the 6 cases with pulp necrosis, the coronal and radicular pulp tissue was necrotic and colonized by bacterial biofilms. The apical papilla could not be discerned, except for one case. HERS was absent in the necrotic cases.
While immature teeth with reversible pulpitis showed histologic features almost similar to normal teeth in the canal and in the apical region, those with irreversible pulpitis and necrosis exhibited significant alterations not only in the radicular pulp but also in the apical tissues, including the apical papilla and HERS.
Alterations in the radicular pulp and apical tissues help explain the outcome of current regenerative/reparative therapies and should be taken into account when devising more predictable therapeutic protocols for teeth with incomplete root formation.
文献中缺乏对人类未成熟牙齿牙髓及相关根尖结构因深龋而发生的病理变化的描述。
本文描述了人类未成熟牙齿牙髓炎症和坏死后与根髓及根尖组织相关的组织学事件。
从8例患者中获取12颗患有破坏性龋损的未成熟牙齿。选取2颗完整的未成熟牙齿作为对照。牙齿因与本研究无关的原因拔除，并立即进行组织病理学和组织细菌学分析。对连续切片进行牙髓状况检查，并分类为可逆性或不可逆性牙髓炎症或牙髓坏死。还评估了其他组织学参数。
在3例可逆性牙髓炎症病例中，髓室内组织显示轻度至中度炎症以及与龋损过程中涉及的小管相关的第三期牙本质形成。总体而言，根髓组织、根尖乳头和赫特维希上皮根鞘（HERS）表现出正常特征。在3例不可逆性牙髓炎症病例中，牙髓暴露，髓室内发生严重炎症，有小面积坏死和感染。根管壁大片区域无成牙本质细胞，由无小管矿化组织衬里。根尖乳头细胞数量极度减少或无细胞，HERS不连续或缺失。在6例牙髓坏死病例中，冠髓和根髓组织坏死，被细菌生物膜定植。除1例病例外，无法辨认根尖乳头。坏死病例中HERS缺失。
虽然患有可逆性牙髓炎的未成熟牙齿在根管和根尖区域显示出与正常牙齿几乎相似的组织学特征，但患有不可逆性牙髓炎和坏死的牙齿不仅在根髓而且在根尖组织，包括根尖乳头和HERS中表现出显著改变。
根髓和根尖组织的改变有助于解释当前再生/修复治疗的结果，并且在为牙根形成不完全的牙齿设计更可预测的治疗方案时应予以考虑。
