Non‐surgical and guided‐bone‐regeneration surgical management of Type‐3b dens invaginatus with an apico‐marginal defect: A case report
Authors: Rahman Aaliya , Alam Sharique , Zia Afaf , Tiwari R. K. , Andrabi S. Mukhtar Un Nisar , Mahmood Maahin 
Published: March 2024

AbstractBackgroundDens invaginatus (DI), an unusual developmental anomaly is a challenge for the operating dentist with regard to its diagnosis and treatment. This case report presents the successful management of a Type‐3b DI in a permanent maxillary lateral incisor associated with a large radicular cyst and communicating apico‐marginal defect (Von Arx type IIb).Methods and ResultsA 19‐year‐old female patient reported pain and palatal swelling. During the clinical examination, tooth #12 exhibited tenderness to percussion, and presented a deep periodontal pocket depth (PPD) of 12 mm, along with grade I mobility. Radiographic examination revealed a large peri‐radicular radiolucency with atypical tooth morphology. Cone beam computed tomography clarified the complicated root canal anatomy to be Type‐3b DI associated with an apico‐marginal defect. The case was managed successfully by non‐surgical endodontic therapy followed by surgical intervention utilizing a guided bone regenerative (GBR) approach. Eighteen‐month follow‐up showed an asymptomatic and functional tooth with a significant reduction in pocket depth. The periapical radiographs showed continued healing of the osseous defect.ConclusionsThe successful healing outcome of a challenging case, characterized by a complex DI morphology, a large peri‐radicular lesion, a through‐and‐through defect, and a combined endodontic‐periodontal apico‐marginal defect was achieved through accurate diagnosis, treatment planning, and execution using contemporary endodontic and periodontal treatment techniques. The application of GBR techniques during the surgical phase of treatment may have contributed to the improved regenerative healing outcome in this case, which was initially considered prognostically questionable.Key pointsWhy is this case new information?

Type‐3b DI exhibits a complex root canal structure, each case displaying unique characteristics, necessitating a case‐specific treatment plan. In this case report the Type‐3b DI morphology was associated with a large peri‐radicular, through and through defect and combined endodontic periodontal apico‐marginal defect. The treatment approach involved incorporating guided bone regenerative (GBR) principles during the surgical phase. This case report contributes to the existing evidence on the diagnosis and successful management of Type‐3b DI with a concurrent apico‐marginal defect.
What are the keys to successful management of this case?

The successful management of a prognostically challenging case was achieved through a closely integrated multidisciplinary coordination between the endodontist and periodontist.
Utilization of contemporary techniques and tools contributed to the successful management
The use of three‐dimensional radiological examination through cone beam computed tomography enabled a precise preoperative assessment, facilitating the formulation of a treatment plan for managing both the Type‐3b DI morphology and the associated peri‐radicular lesion.
Employing GBR techniques in peri‐radicular surgery may have assisted in the healing of through‐and‐through periapical defects with concurrent apico‐marginal defects (Von Arx type IIb).
What are the primary limitations to the success of this case?

A complex root canal anatomy associated with Type‐3b DI morphology
A large peri‐radicular through and through defect with concurrent apico‐marginal defect.
Difficulty in weekly and long‐term follow‐up of the patient.