Management of large class II lesions in molars: how to restore and when to perform surgical crown lengthening?

Abstract

The restoration of endodontic tooth is always a challenge for the clinician, not only due to excessive loss of tooth structure but also invasion of the biological width due to large decayed lesions. In this paper, the 7 most common clinical scenarios in molars with class II lesions ever deeper were examined. This includes both the type of restoration (direct or indirect) and the management of the cavity margin, such as the need for deep margin elevation (DME) or crown lengthening. It is necessary to have the DME when the healthy tooth remnant is in the sulcus or at the epithelium level. For caries that reaches the connective tissue or the bone crest, crown lengthening is required. Endocrowns are a good treatment option in the endodontically treated tooth when the loss of structure is advanced.

Keywords: Caries; Dental restoration; Endodontically treated teeth; Molar; Periodontitis.

Chart 1

Decision tree. DME, deep margin elevation; SCL, surgical crown lengthening.

Figure 1

Scenario 1. (A) Diagram: supragingival caries does not reach the pulp. (B) Initial photography: caries cavity in molar tooth #16 does not invade the pulp tissue or periradicular tissues. (C) Preoperative bite-wing radiography. (D) Isolation using a rubber dam and wedged matrix to prevent damage to the adjacent tooth. (E) Exposure of caries. (F, G) Clean cavity: note that the cavity does not reach the periodontal tissues. (H) Obturation using the Palodent Plus system (DeTrey Dentsply, Konstanz, Germany). (I) Final photograph after checking for occlusion. (J) One-year control radiograph.

Figure 2

Scenario 2. (A) Diagram: supragingival caries invading the pulp tissue. (B) Initial radiograph showing cavities in molar tooth #36. (C) Pulp chamber in which the entrance of 5 canals is noted. (D) Obturation of the root canal system. (E) Note that the distal cavity margin is above the gingival sulcus. (F) Use of the Palodent Plus system (DeTrey Dentsply, Konstanz, Germany) to reach a good contact point. (G) Completed distal wall. (H) Final photograph after anatomical characterization. (I) One-year X-ray control: correct root canal treatment and direct reconstruction.

Figure 3

Scenario 3. (A) Diagram: juxta-gingival decay that reaches the pulp. (B) Initial radiography: filtered restoration of tooth #26 and large cavities under the amalgam on tooth #27. (C) Root canal treatment of tooth #27. (D) Elimination of the filtering margin for tooth #26 and build-up on tooth #27. Note the margins at the juxta-gingival level. (E) Final photograph after composite endocrown cementation on teeth #26 and #27. (F) X-ray control of the correct operation at 1-year after treatment.

Figure 4

Scenario 4. (A) Diagram: caries invades the gingival sulcus and the pulp chamber. (B) Initial radiograph: presence of apical focus on the distal root of tooth #36. (C) Initial photograph: note the clean margin within the gingival sulcus. (D, E) Retreatment of the distal canal. (F) Final photograph after cementation of the composite endocrown. (G) X-ray control at 1-year. Note the complete healing of the lesion and fit of the restoration.

Figure 5

Scenario 5. (A) Diagram: caries with a margin in the junctional epithelium and reaching the pulp. (B) Initial radiograph: mesial and distal cavities in tooth #46. (C) Radiograph of the root canal treatment. (D, E) Mesial and distal margins free of caries. Note margins have already invaded the epithelial tissue. (F) DME with AutoMatrix (DeTrey Dentsply, Konstanz, Germany) and under total isolation. (G) Build-up of the future endocrown. Note buccal and lingual cusp protection. (H) Final photograph. (I) X-ray control at 1-year after treatment. DME, deep margin elevation.

Figure 6

Scenario 6. (A) Diagram: caries invades the connective tissue and pulp. (B, C) Initial bitewing and periapical radiography, respectively; mesial caries in tooth #17 under an amalgam filling. (D) Periapical view after root canal treatment. (E) Remaining tooth structure after root canal treatment. Note how the margin is invading the connective tissue. (F, G) Tooth #17 after crown lengthening. Note how it gained at least a 2-mm supragingival margin. (H, I) Composite endocrown Lava Ultimate CAD/CAM (3M ESPE) on a laboratory model. (J) Final photograph. (K) X-ray control at 1-year after treatment.

Figure 7

Scenario 7. (A) Diagram: decay that reached the bone level and invaded the pulp chamber. (B) Initial radiograph: deep filtered obturation in tooth #46. (C) Photograph after root canal treatment. Note that the distal margin of the cavity is completely at the bone level. (D) Radiograph after crown lengthening and after the DME. (E) Photograph after cementation of the endocrown and after occlusal check. (F) Periapical radiography control at 1-year. Correct operation of the treatment. DME, deep margin elevation.