Working length determination was performed at a subsequent visit. The root canals were instrumented and obturated using a calcium silicate–based sealer and single-cone technique (Fig. 2L). The access cavity was restored with resin composite (Fig. 2M).

Considerations. This case would be classified as a Type II-1 defect according to Khanvilkar et al., (2024). Although the gingival seat was located subgingivally, the gingival margin of the cavity could be exposed and adequately isolated using a ligature. Consequently, a single-visit root canal treatment approach would have been feasible. Nevertheless, the pre-endodontic build-up provided several clinical advantages that facilitated treatment and contributed to an optimal outcome.

Case 2. A 67-year-old man presented with severe spontaneous dental pain but was unable to identify the offending tooth. The maxillary second premolar did not respond to cold testing, while heat testing elicited delayed, intense, and lingering pain. The tooth was tender to both vertical and lateral percussion. A periapical radiograph revealed a large recurrent carious lesion located apical to a distal composite restoration and extending close to the pulp chamber, along with widening of the apical periodontal ligament space (Fig. 3A).

The tooth was diagnosed as pulp necrosis and symptomatic apical periodontitis. Root canal treatment was recommended. Following local anesthesia and rubber dam isolation, the existing restoration was removed and carious tissue excavated until sound dentin was reached at the cavity floor. The pulp chamber was exposed and contained avascular pulp tissue. Although the cavity floor could be adequately isolated for root canal treatment to be initiated immediately, the apical extent of the defect and the possibility of requiring intracanal medication favored performing a pre-endodontic build-up before canal treatment.

A procedure similar to that described in Case 1 was carried out. A matrix band was placed and stabilized with a sectional ring (Fig. 3B), and the distal anatomic contour was reconstructed and polished. Canal negotiation, working length determination, and chemomechanical preparation were then completed (Fig. 3C). The canals were medicated with calcium hydroxide mixed with sterile saline to a creamy consistency, and the access cavity was temporarily sealed.

The patient's symptoms resolved following this intervention. One week later, the canals were obturated using a bioceramic sealer and single-cone technique (Fig. 3D). For patient convenience, the definitive coronal restoration was placed at a subsequent appointment (Fig. 3E). At the two-year follow-up, the tooth remained asymptomatic, and the periapical radiograph demonstrated normal periapical conditions (Fig. 3F).

Considerations. Similar to Case 1, this case would be classified as a Type II-1 defect according to Khanvilkar et al. (2024), with a subgingival defect extent that remained amenable to isolation and restorative management. However, because of the presence of pulp necrosis and infection, and the consequent need for intracanal medication, a pre-endodontic build-up was strongly indicated. This procedure substantially reduces the risk of bacterial leakage associated with the inadequate adaptation of temporary restorative materials to a subgingival cavity floor. It also reinforces the remaining tooth structure.

Case 3. A 48-year-old man presented with pain associated with his mandibular first molar, which had undergone caries treatment approximately two years earlier. A periapical radiograph revealed a deep composite restoration and a radiolucent area superimposed over the mesial aspect of the pulp chamber (Fig. 4A). The tooth did not respond to thermal testing and exhibited slight tenderness to percussion. Clinical examination revealed a buccal swelling suggestive of a healed sinus tract that was not actively draining, along with a grayish discoloration of the crown and a small opening at the cemento-enamel junction (Fig. 4B). No periodontal pocketing was detected around the tooth or in association with the opening, with probing depths not exceeding 2 mm. 

The tooth was diagnosed as external cervical invasive resorption (ECIR) associated with pulp necrosis. A cone beam computed tomography scan was requested. The scan revealed a resorptive tunnel extending through the buccal dentinal wall and communicating with the pulp chamber (Fig. 4C–I). Because this well-defined resorptive lesion was largely confined to the cervical region and exhibited little or no extension into the radicular dentin, it was classified as a Heithersay Class 2 ECIR defect (Heithersay 1999). The treatment plan included root canal therapy. As a preliminary step, the existing resin composite restoration was removed, and the resorptive tunnel was accessed from within the pulp chamber. The defect walls were debrided with low-speed round burs up to the buccal portal of entry, which was located just coronal to the gingival sulcus (Fig. 4J). The buccal wall was then reconstructed with an adhesively bonded resin composite. (Fig. 4K). 

The subsequent step involved removal of the defective restorative material on the distolingual aspect of the tooth (Fig. 4L–M). Existing crack lines were minimally extended with a thin fissure bur. The canal orifices were protected with calcium hydroxide prior to reconstruction of the distal and lingual walls (Fig. 4N). The restored walls were carefully finished and polished, after which root canal treatment was completed over two appointments (Fig. 4O–Q). The pulp chamber was then restored with adhesively bonded resin composite. A clinical photograph of the buccal aspect demonstrated recovery of the normal crown color (Fig. 4R). Prosthetic preparation was subsequently performed (Fig. 4S), and treatment was completed with cementation of a zirconia-ceramic full crown (Fig. 4T).

Considerations. In cases like this, a large resorptive defect communicates with the gingival sulcus and is accompanied by a defective restoration and crack lines. Elimination of infection sources and closure of potential bacterial leakage pathways through a pre-endodontic build-up should therefore be considered mandatory from both biological and microbiological perspectives. By re-establishing a four-walled access cavity, the procedure creates a more favorable environment for root canal treatment. In addition, these preliminary measures substantially facilitate the endodontic workflow by enabling reliable isolation and providing stable reference points for working length determination and instrument manipulation. It should be noted that the management approach presented in this case of ECIR is applicable primarily to selected lesions, such as Heithersay Class II defects, and may not be appropriate for more advanced lesions with a less favorable prognosis.

Case 4. A 32-year-old woman presented with a mandibular first molar diagnosed with irreversible pulpitis. The preoperative radiograph revealed an extensive distal carious lesion extending into the pulp chamber, along with periapical changes (Fig. 5A). The treatment plan included root canal therapy followed by full-coverage crown restoration.

After administration of local anesthesia, rubber dam isolation of the quadrant, and access to the lesion, a large mass of soft carious dentin was encountered (Fig. 5B). Following gross caries removal and elimination of the remaining restorative material, the roof of the pulp chamber was found to be completely absent (Fig. 5C). Complete caries excavation was then performed, together with removal of the thin unsupported distolingual enamel (Fig. 5D).

At the completion of caries removal, isolation remained suboptimal despite the use of a cervical ligature. Therefore, the pulp tissue was protected and a pre-endodontic build-up of the missing distal and distolingual walls was carried out. This reconstruction re-established the coronal contours and facilitated completion of root canal treatment at subsequent appointments under straightforward isolation of the individual tooth (Fig. 5E). A post-operative radiograph was then obtained (Fig. 5F).

Following root canal treatment, a glass fiber post was placed in the distal canal, and the coronal structure was rebuilt with resin composite. Prosthetic preparation was subsequently performed, and treatment was completed with cementation of a zirconia-ceramic crown. The tooth remained asymptomatic at the four-year follow-up. Radiographic examination demonstrated normal periradicular conditions (Fig. 5G).

Considerations. The condition of this tooth is difficult to categorize within the Khanvilkar et al. classification. This case exemplifies a clinical scenario in which a pre-endodontic build-up offers clear procedural advantages. By re-establishing the missing coronal walls prior to root canal treatment, the procedure significantly improves isolation and moisture control, facilitates rubber dam management, and creates a more contained and predictable operative field. In addition, the reconstructed walls provide stable reference points for access refinement, canal location, working length determination, and instrument manipulation.

Case 5. A 60-year-old woman presented after noticing the fracture of the buccal cusp of a maxillary premolar. She expressed a desire to replace metallic restorations that had been in service for more than 30 years with tooth-colored restorations. Clinical examination revealed extensive interproximal amalgam restorations on both maxillary premolars and the first molar, together with fracture of the buccal cusp of the second premolar (Fig. 6A–B). 

The patient reported that all teeth were asymptomatic and denied any history of spontaneous pain or discomfort. Both premolars responded weakly to pulp sensibility tests.

Radiographic examination showed no evidence of periapical pathology and revealed marked reduction in pulp chamber volume in both premolars, consistent with extensive tertiary dentin deposition (Fig. 6C).

The treatment plan included replacement of the first molar amalgam with an MO resin composite restoration and restoration of both premolars with full-coverage crowns. Because of the extensive loss of tooth structure and the anticipated need for substantial prosthetic preparation, preventive root canal treatment was planned for both premolars.

Following local anesthesia, the existing restorations were removed without rubber dam isolation to enable direct assessment of the underlying cavity dentin (Fig. 6D–E). The interdental periodontal tissues were then examined, and large deposits of subgingival calculus were removed using curettes (Fig. 6F). Residual carious tissue beneath the restorations was meticulously excavated (Fig. 6G). This procedure confirmed the extremely limited amount of remaining coronal tooth structure and revealed that the interproximal cavity margins of both premolars were located subgingivally, largely as a consequence of inflammation and edema of the interdental papillae (Fig. 6G). The cavities were temporarily restored with Cavit™ and the patient was instructed to improve oral hygiene.

A pre-endodontic build-up was performed at a subsequent appointment, following local anesthesia and rubber dam isolation. The cusps were reduced to facilitate future prosthetic preparation, and the remaining dentin and enamel were thoroughly cleaned. Circumferential matrix bands (AutoMatrix®, Dentsply Caulk) were then placed, and both premolars were sequentially rebuilt with resin composite (Fig. 6H–I). The reconstructed coronal walls subsequently allowed pulpectomy of both premolars to be carried out under optimal isolation conditions and with stable coronal reference points for endodontic procedures (Fig. 6J–K). The root canal orifices were intentionally left unfilled to maximize composite retention, and the access cavities were restored with bonded resin composite. Prosthetic preparation was then performed, followed by placement of provisional crowns. This approach promoted resolution of the periodontal inflammation and allowed maturation of the soft tissues, resulting in optimal periodontal conditions for impression making after a few weeks (Fig. 6L–M).

Considerations. Similar to Case 4, the condition of these two premolars would be difficult to categorize within the Khanvilkar et al. classification. The defects correspond most closely to type II-2 but are further complicated by the absence of the buccal wall in the second premolar and the need to remove the very thin residual buccal and palatal enamel walls in the first premolar, as well as the palatal wall in the second premolar. Nevertheless, successful isolation of both teeth enabled reconstruction of the missing walls with resin composite. This provided aseptic operating conditions, stable reference points for working length determination and instrument manipulation, and allowed placement of the temporary restoration within a four-walled access cavity.

Case 6. A 26-year-old man presented with a complaint of food impaction in a cavity of the mandibular right first molar during mastication. The diagnostic radiograph revealed a previously root canal–treated tooth with a periapical radiolucency associated with the mesial root and a large cavitated lesion on the mesial aspect of the crown. A post was present in the distal root (Fig. 7A). Clinical examination showed gingival tissue proliferation into the cavity, obscuring the cervical margin of the tooth (Fig. 7B). Nonsurgical root canal retreatment was planned.

The treatment plan included nonsurgical root canal retreatment followed by cuspal coverage. Preliminary procedures to facilitate rubber dam isolation were considered necessary. Access to the mesial cavity, achieved by removing a portion of the existing composite restoration, confirmed that the gingival overgrowth would interfere with proper isolation (Fig. 7C). Carious tissue was excavated, and electrosurgery was carefully performed to expose the cervical margin on the mesial surface without violating the periodontal attachment. This allowed placement of a matrix band (Fig. 7D) and reconstruction of the mesial wall with resin composite. Because of the apical extension of the mesial defect margin, placement of a rubber dam was not feasible during the pre-endodontic build-up procedure. Nevertheless, every effort was made to minimize moisture contamination during the adhesive procedures. Following refinement and polishing of the build-up, root canal retreatment was initiated under optimal isolation conditions (Fig. 7E). The root canals were obturated after two weeks of calcium hydroxide medication (Fig. 7F), and the crown was subsequently restored. At the three-year follow-up, complete periapical healing was observed (Fig. 7G).

Considerations. Ideally, adhesive build-up procedures should be performed under rubber dam isolation. In this case, however, the apical position of the mesial margin precluded dam placement before reconstruction. The decision to proceed with the build-up under carefully controlled relative isolation was based on the need to create a coronal wall that would permit rubber dam placement and optimal asepsis during retreatment. The favorable three-year outcome suggests that this compromise was clinically acceptable in the present case.

Case 7. A 34-year-old man requested restoration of a previously treated, severely broken-down mandibular first molar. A periapical radiograph revealed inadequate root canal treatment and periapical radiolucencies associated with both roots (Fig. 8A). 

Clinical examination showed complete loss of the coronal walls, with residual composite material surrounded by carious tissue (Fig. 8B). The treatment plan included nonsurgical root canal retreatment followed by restoration with a full-coverage crown. 

After removal of the existing restorative materials, it became evident that rubber dam isolation could not be achieved because the defect margins extended well below the gingival margins (Fig. 8C). It was decided to proceed with complete caries excavation. A cautious gingivectomy was performed using electrosurgery. This enabled circumferential exposure of sound tooth structure, although rubber dam isolation remained unfeasible at this stage. A tightly adapted matrix was then placed under careful moisture control, allowing reconstruction of 2–3 mm of the missing coronal walls circumferentially with resin composite. The build-up was subsequently finished and polished (Fig. 8D), and the access cavity was temporized. After five days, gingival healing was progressing satisfactorily (Fig. 8E), and the tooth could then be isolated readily with a rubber dam (Fig. 8F). After removal of the root filling materials, the canals were instrumented (Fig. 8G–I) and medicated with calcium hydroxide. Root canal obturation was performed two weeks later (Fig. 8J–K). The pulp chamber was subsequently restored with resin composite (Fig. 8L), followed by tooth preparation for full-coverage restoration. After impression taking, a lithium disilicate crown was fabricated and adhesively cemented (Fig. 8M–N). A two-year follow-up radiograph demonstrated normal periapical conditions, and the tooth remained asymptomatic (Fig. 8O).

Considerations. Similar to the previous case, a compromise was required, as the initial build-up had to be performed without rubber dam isolation. The deep subgingival extension of the defect precluded immediate dam placement. Nevertheless, reconstruction of the coronal walls was necessary to create the conditions for subsequent isolation and retreatment. This approach allowed preservation of the tooth and avoided the need for periodontal surgical procedures, such as crown lengthening, to expose the defect margins. Careful moisture control during the build-up phase and definitive treatment under rubber dam isolation resulted in a favorable clinical and radiographic outcome.

Case 8. A 38-year-old woman presented with fracture of a resin composite restoration and food impaction in a mandibular first molar. A periapical radiograph revealed a periapical radiolucency associated with the distal root and separated instruments within the mesial root canals (Fig. 9A). The treatment plan included nonsurgical root canal retreatment followed by restoration with a full-coverage crown. Access to the pulp chamber was established as a preliminary step (Fig. 9B), and all existing restorative materials were removed. This procedure revealed that the lingual defect margin extended well below the gingival level. Consequently, gingivectomy was performed using electrosurgery to expose sound tooth structure (Fig. 9C). Because rubber dam isolation could not be achieved initially, a matrix band was tightly secured with a matrix retainer under careful moisture control. This enabled reconstruction of the missing coronal walls with composite resin (Fig. 9D). The build-up was then finished and polished (Fig. 9E), after which ideal rubber dam isolation could be established (Fig. 9F). Root canal retreatment, including removal of the separated instruments, was completed during subsequent visits (Fig. 9G). The pulp chamber was then restored with resin composite, and the tooth was rehabilitated with a zirconia-based porcelain crown (Fig. 9H). At the two-year follow-up, the tooth was asymptomatic, and radiographic examination demonstrated ongoing healing of the periapical radiolucency (Fig. 9I).

Considerations. In this case, the deep lingual extension of the defect prevented rubber dam placement at the outset of treatment. Although performing the pre-endodontic build-up without rubber dam isolation represented a compromise, reconstruction of the missing walls was necessary to create the conditions required for definitive isolation. Careful moisture control and a tightly adapted matrix allowed establishment of a stable coronal build-up, after which ideal rubber dam isolation could be achieved for retreatment. The favorable clinical and radiographic outcome suggests that this staged approach provided an acceptable solution when immediate isolation was not feasible.

Discussion

Preservation of structurally compromised teeth requires close integration of endodontic and restorative procedures (Gavriil et al., 2021). Although successful elimination of infection and adequate root canal obturation remain fundamental objectives of endodontic treatment, long-term tooth survival depends equally on the ability to restore and maintain the remaining tooth structure. The cases presented in this article illustrate how pre-endodontic adhesive reconstruction can facilitate both biological and technical aspects of treatment by re-establishing coronal integrity before initiation or completion of root canal therapy.

Traditionally, root canal treatment is performed before definitive restoration of the tooth. However, this sequence may be problematic when extensive coronal destruction is present. Loss of coronal walls compromises isolation, reduces structural stability during treatment, and often necessitates placement of temporary restorations in cavities with unfavorable geometry. In contrast, reconstruction of missing walls before root canal treatment creates a more contained operative field, improves access and visibility. This procedure also allows more predictable placement of temporary restorations when multiple visits are required. The clinical cases presented here demonstrate these advantages across a spectrum of structural defects ranging from localized proximal destruction to near-complete loss of the clinical crown.

The extent and distribution of structural loss are major determinants of treatment complexity. While the quantity of remaining tooth structure has long been recognized as an important factor influencing fracture resistance and restorative prognosis, its effect on the technical execution of endodontic procedures is often underappreciated. Missing walls and marginal ridges reduce the ability of a clinician to maintain asepsis, manipulate instruments, and establish stable reference points for working length determination. Reconstructing lost coronal structures before root canal treatment can restore these reference points and improve the predictability of endodontic procedures. Moreover, re-establishing missing coronal walls facilitates maintenance of an irrigant reservoir within the pulp chamber, improving irrigant containment and potentially enhancing the effectiveness of irrigation during canal preparation. In the present series, the benefits of reconstruction became progressively more evident as the severity of structural compromise increased.

Among the factors influencing treatment planning, the apico-coronal position of defect margins deserves particular attention. Defects extending toward or below the gingival margin present challenges related to access, visualization, matrix adaptation, and moisture control. Furthermore, the relationship between restorative margins and the supracrestal tissue attachment must be carefully evaluated to avoid compromising periodontal health. Contemporary adhesive techniques such as DME (Aldakheel et al., 2022; Taylor & Burns, 2024) and CMR (Ghezzi et al., 2019; Geo et al., 2023) have expanded the range of defects that can be managed conservatively. Nevertheless, clinical decision-making is dependent on the depth and configuration of the defect, the condition of the surrounding periodontal tissues, and the feasibility of obtaining adequate isolation. The cases presented here illustrate that management of the soft tissues, including removal of inflammatory enlargement and limited gingivectomy when indicated, may substantially improve access to sound tooth structure and facilitate restorative procedures.

A particularly important clinical issue highlighted by several cases is the relationship between adhesive reconstruction and rubber dam isolation. Ideally, all adhesive procedures should be performed under rubber dam isolation to maximize bond quality and minimize contamination. However, severely compromised teeth occasionally present a paradoxical situation in which rubber dam placement is impossible until sufficient coronal structure has first been rebuilt. Cases 6 through 8 exemplify this dilemma. In these situations, a carefully controlled compromise was adopted: the initial build-up was performed under meticulous moisture control and with tightly adapted matrix systems, with the primary objective of creating conditions that would subsequently permit ideal rubber dam isolation. Although this approach deviates from the ideal restorative protocol, it allowed definitive endodontic treatment to be completed under optimal aseptic conditions. The favorable clinical and radiographic outcomes observed during follow-up suggest that such a staged approach may be a reasonable alternative when immediate isolation is not feasible. Nevertheless, further research is needed to evaluate the long-term performance of adhesive restorations placed under these challenging circumstances.

The biological rationale for pre-endodontic reconstruction extends beyond improvements in isolation and clinical convenience. Coronal leakage has long been recognized as a potential source of endodontic contamination and treatment failure (Gillen et al., 2011). Reconstruction of missing walls before root canal treatment can reduce pathways for bacterial ingress and improve adaptation of temporary restorative materials, particularly in teeth requiring multiple treatment visits. This consideration may be especially important in cases of pulp necrosis, retreatment, cervical resorption, and extensive carious destruction, where bacterial contamination of both the root canal system and surrounding structures is already established. By restoring coronal integrity at an early stage, the clinician may improve the microbiological environment in which endodontic treatment is performed.

The cases presented also reinforce the importance of restorability assessment before initiating endodontic treatment. Endodontic diagnosis alone does not determine whether a tooth can be predictably maintained in function. Careful evaluation of the quantity, distribution, and quality of the remaining tooth structure, together with periodontal and restorative considerations, should precede treatment decisions. Advances in adhesive dentistry have expanded the range of teeth that can be preserved through conservative means. Several cases in this series involved teeth that would historically have been considered questionable candidates for retention, yet successful rehabilitation was achieved through a combination of adhesive reconstruction, endodontic treatment, and definitive cuspal coverage.

The classification proposed by Khanvilkar et al. (2024) provides a useful framework for describing structural defects and planning pre-endodontic build-up procedures. The present cases generally support the clinical relevance of considering both the number of missing walls and the position of restorative margins. However, the series also highlights certain limitations of the classification. Several cases could not be categorized easily because treatment complexity was influenced by factors not directly incorporated into the system, including the presence of cracks, external cervical resorption, complete loss of the pulp chamber roof, periodontal inflammation, previous endodontic treatment, and the feasibility of achieving isolation. These observations suggest that although classification systems can facilitate communication and treatment planning, comprehensive clinical evaluation remains essential.

From a practical perspective, the cases demonstrate that treatment planning should remain flexible until complete caries excavation and removal of defective restorative materials have been performed. The true extent of structural loss and the relationship of defect margins to the gingival tissues are often impossible to determine accurately from clinical and radiographic examination alone. Consequently, the final restorative strategy frequently becomes apparent only after exposure of sound tooth structure. In many situations, pre-endodontic reconstruction should be viewed not as an optional adjunctive procedure but as an integral component of treatment that contributes directly to both endodontic and restorative success.

The present article has several limitations. As a clinical case series, it does not permit direct comparison with alternative treatment approaches or establish causal relationships between pre-endodontic build-up and treatment outcomes. The cases represent a heterogeneous group of clinical situations with varying degrees of structural loss, different treatment objectives, and different follow-up periods. In addition, long-term survival of the adhesive reconstructions themselves was not specifically evaluated. Prospective clinical studies are needed to determine the influence of pre-endodontic build-up on treatment efficiency, coronal leakage, restoration longevity, and long-term tooth survival.

Within these limitations, the cases presented support the concept that pre-endodontic adhesive reconstruction can play an important role in the management of structurally compromised teeth. By facilitating isolation, improving asepsis, restoring structural integrity, and creating a more predictable restorative-endodontic workflow, rebuilding the tooth before the root canal may enhance both the technical execution of treatment and the long-term prognosis of the restored tooth.