A 63-year-old male patient presented to the clinic with the complaint of movement in a maxillary anterior prosthesis that had been placed five years ago. Clinical and radiographic examinations revealed that his maxillary right lateral incisor, used as the abutment tooth for a three-unit fixed dental prosthesis, had a secondary caries with inadequate structural support, causing bucco-lingual movement of the prosthesis. A noteworthy finding in this prosthesis was a maxillary right central incisor root remnant, which had been covered by soft tissue and remained for five years underneath the pontic site (Fig. 1A). The radiographic and clinical evaluation showed no inflammation, dehiscence, external root resorption, or any known pathologies, and the arch form was maintained without any sign of ridge deformation. It was evident that a submerged root of the maxillary right central incisor had prevented bone resorption, especially in the interproximal area. Due to the severe secondary caries, the prognosis for the maxillary right lateral incisor was poor: it was thus submerged as a root remnant at the pontic site. The tooth was endodontically treated due to the periapical lesion, then decoronated at a crestal bone level similar to that of the maxillary right central incisor. No surgical intervention was performed, and an interim fixed dental prosthesis supported by the maxillary right canine and maxillary left central incisor was fabricated, relieving pressure on the soft tissue under the pontic sites. After a three-month healing period, the root was completely covered by soft tissue, and the periapical lesion was disappeared (Fig. 1B). No noticeable changes were observed in the alveolar ridge of the pontic site either vertically or horizontally. Upon completion of the healing process, a metal ceramic fixed dental prosthesis was fabricated and cemented with a resin-modified glass-ionomer cement. Since the submerged roots preserved the bone and soft tissue, the gingival contour of the pontic site was in harmony with the gingival margins of the adjacent abutment teeth. At a two-year follow-up visit, the bone level at the submerged root site was stable, and the gingival contour under the pontic site was maintained (Fig. 1C, D). The patient was satisfied with the outcome of the prosthetic rehabilitation.

An 83-year-old male patient presented with a gross caries on the disto-cervical surface of the maxillary right lateral incisor with food impaction and discoloration. Clinical and radiographic evaluation indicated that the tooth was non-vital, and that the cavity extended to the crestal bone level (Fig. 2A). Among several treatment options, ranging from a post-and-core crown to implant placement following a tooth extraction, the patient decided to submerge the root of the lateral incisor and undergo restoration with a three-unit fixed dental prosthesis. The prosthesis was intended to have the additional benefit of addressing severe attrition in the adjacent maxillary right central incisor and canine. Single-visit endodontic treatment was performed on the maxillary right lateral incisor, with decoronation at the level of the alveolar crest. No soft tissue augmentation was performed on the decoronated area, and the root was completely covered by gingival tissue five months after the decoronation procedure. A three-unit metal ceramic restoration was fabricated and cemented with a resin-modified glass-ionomer cement. At a three-month follow-up visit, the architecture of the hard and soft tissue was found to have been preserved at the pontic site, and no pathology was noted (Fig. 2B).

A 51-year-old male patient presented to the clinic with a fractured maxillary left lateral incisor tooth and severe toothache. The patient had previously experienced severe periodontitis and had lost the maxillary central incisors, resulting in a compromised residual ridge. The radiographic and clinical examination indicated a poor prognosis for the maxillary left lateral incisor, due to a compromised crown-to-root ratio and exposed pulpal tissue (Fig. 3A). The maxillary left lateral incisor had a peg lateralis shape and was not a suitable retainer tooth for the planned fixed dental prosthesis. Rather than using the maxillary lateral incisor as an abutment tooth, the fixed dental prosthesis was extended to the maxillary left canine, with the maxillary left lateral incisor submerged in order to preserve the already compromised ridge. After a single-visit root canal treatment and root decoronation to the crestal bone level, the root was completely covered by soft tissue within six months. Upon completion of the healing process, no signs of inflammation or dehiscence were noted, although minimal interproximal bone loss had taken place. A five-unit metal ceramic fixed dental prosthesis was fabricated, and the patient underwent follow-up 24 months later (Fig. 3B).