Dentin dysplasia (DD) Type I is a developmental condition affecting dentin, inherited in an autosomal‐dominant pattern or occurring due to a new mutation. Whilst the crowns of DD Type I affected teeth appear clinically normal, the roots are blunt and shortened. Pulp necrosis and periapical pathoses may be seen in the absence of obvious causes. Pulp stones and calcifications are frequently encountered. Endodontic management of DD may be challenging. A case of DD Type I, sub‐classification d, in which spontaneous irreversible pulpitis developed on three mandibular incisors is documented. The case was managed by conventional endodontic treatment. Knowledge of this uncommon dental condition may assist dentists to adequately diagnose and manage these cases. Extraction should not be considered the first‐line treatment option when sufficient root length is available to attempt endodontic treatment. Referral for medical evaluation is recommended to rule out systemic diseases which may mimic this condition.