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Published on: August 6, 2019
Histologic Study of a Human Immature Permanent Premolar with Chronic Apical Periodontitis after Regenerative
Feng Yang1, Xueqin Zhu1, Xinyi Tan1
1Department of Pediatric Dentistry, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; College of Stomatology, Shanghai Jiao Tong University, Shanghai, China; National Center for Stomatology, Shanghai, China; National Clinical Research Center for Oral Diseases, Shanghai, China; Shanghai Key Laboratory of Stomatology, Shanghai, China; Shanghai Research Institute of Stomatology, Shanghai, China.
None:
The histologic outcomes of regenerative endodontic procedures (REPs) in humans remain debated, with evidence varying between cementum-/bone-like tissue and true pulp-dentin complex regeneration. Here, we present a case of a 10-year-old girl who underwent REPs for a maxillary premolar (tooth #4) diagnosed as symptomatic irreversible pulpitis with symptomatic apical periodontitis. At the 8-month follow-up, the patient was asymptomatic with radiographic evidence of apical closure and dentinal wall thickening; the tooth was subsequently extracted due to orthodontic indications, along with the sound contralateral premolar (tooth #12) as control. Micro-computed tomography confirmed apical closure and dentinal wall thickening with heterogeneous intracanal mineralization in tooth #4. Histologic examination revealed dentin-like tissue with tubular structures, surfaced by flattened, dentin sialophosphoprotein-positive cells. Neurovascular regeneration assessed by CD31/PGP9.5 co-localization was sparse and disorganized compared to the normal control. Osteoid tissue ingrowth was present in the apical region. This case demonstrates that REPs can yield structurally disorganized pulp-dentin-like tissue, highlighting the key challenge of achieving true histologic regeneration.
