13.1 Introduction of the Case

Case of upper right maxillary first molar with porcelain fused to metal crown.

13.1.2 Tooth

• Identification: Right maxillary first molar (Tooth 16)
• Dental history:

  Chief complaint: Patient reported with a chief complaint of tenderness on biting. Occasionally, he felt sensitivity to hot and cold. In addition, complaints of bad taste occasionally.

• Clinical examination findings:

  Tooth 16 is tender to percussion and had a porcelain fused to metal (PFM) crown. The crown was attached to another PFM crown on 15.

• Preoperative radiological assessment:

  The periapical radiograph revealed previous root canal treatment in 15. The following are the observations after reading the preoperative radiograph: (Figure 13.1)

• Short obturation in all the canals.
• Periapical radiolucency around the root of 15
• Suspected fractured instrument in the apical part of the palatal root.

The patient was made aware of the inadequate RCT in relation to 15, but he wanted to treat only the symptomatic tooth, which was 16 in this case. It was made clear to the patient that the investigations can be concluded only after removing the crowns where it will be possible to perform sensibility testing. Once the crowns were removed sensibility testing was performed where the tooth showed delayed response on electric pulp testing (EPT) and only the palatal surface responded to cold testing. The tooth did not respond to heat test at all.

• Diagnosis (pulpal and periapical): Partially necrotic teeth with symptomatic apical periodontitis.

  Root canal treatment of teeth Federation Dentaire Internationale (FDI) 16 and retreatment of 15 was advised to the patient. However, patient wanted to treat only tooth 16. The patient was informed about future course of the lesion (infection) in 15 and what it can lead to.

• Treatment plan

The treatment was planned in different stages:

Stage 1:

• Local anesthetic administration
• Rubber dam isolation
• Gaining entry in the pulp chamber and locating orifices
• Locating the canals
• Exploring the access cavity for extra canals
• Orifice widening

Stage 2:

• Establishing a glide path
• Working length determination (electronic and radiographic)
• Orifice widening
• Cleaning and shaping as per the rotary protocol

Stage 3:

• Master cone verification
• 3D obturation using bioceramic sealer and gutta‐percha (GP)
• Core buildup

Disinfection with irrigants was carried on throughout the root canal procedure as per the recommended protocol.

13.2 Treatment Procedure for the First Appointment

Superior alveolar nerve block and palatine block anesthesia was administered and the tooth was isolated with rubber dam isolation (Figure 13.2). The leakage spaces were isolated with liquid rubber dam. The treatment was initiated under a microscope. Occlusal surface showed resin composite restoration along with remaining residual caries (Figure 13.2).

The first step was to make an endodontic access cavity and then look for the dentinal map. The map will guide us to the orifices (Figure 13.3). Endodontic ultrasonic tips were used to modify the access cavity and adhere to the guidelines of minimal invasive endodontics. Once the access cavity was prepared to have a straight line access to the canals, orifice widening was done using orifice widener rotary file (Dentsply Sirona, USA) (Video 13.1).

Following orifice widening, glide path to the canals was established using 10K hand files. Intracanal medicament was placed and the patient was recalled for the next appointment for working length determination and completion of root canal treatment.

13.3 Treatment Procedure for the Second Appointment

The second appointment was planned to continue the root canal treatment following working length determination, cleaning, and shaping and obturation.

Once the full working length was achieved electronically, periapical radiograph was taken to confirm the same (Figure 13.3).

The canals were finally cleaned and shaped with ProTaper Ultimate files up to size 25/04. EDTA gel, saline, 2.5% sodium hypochlorite, and EDTA liquid were used as irrigants alternatively. Irrigation was done using TruNatomy needles (Dentsply Sirona, USA). Ultrasonic agitation of the irrigants was done with EndoUltra from Dentsply (Video 13.2).

Clinically, the fit of the master cones was checked and verified with a periapical radiograph at the calculated working length (Figure 13.4).

Once the master cone fit was confirmed, the canals were left moist and excessive moisture removed with the help of paper points. The premixed injectable AH Plus Bioceramic sealer (Dentsply Sirona, USA) was applied inside the canals and the master cones were coated with the sealer and placed inside the canals. The gutta‐percha was cut at the orifice level with heated plugger (Video 13.3). All the canals were obturated with warm vertical condensation technique and the pulp chamber cleaned of any gutta‐percha or sealer (Video 13.4). Immediate postoperative radiograph was taken to verify the final obturation (Figure 13.5).

13.4 Technical Aspects

Root canal treatment protocol has evolved with time. With the advent of time, more advanced cleaning and shaping instruments have been developed. These NiTi instruments focus on anatomical shaping while adhering to the guidelines of minimal invasive endodontics. Endodontic ultrasonic tips should be used to stay conservative while cutting tooth structure and modifying access cavities. Excessive removal of tooth structure might lead to fracture of the tooth due to low strength. Copious irrigation should be maintained throughout the procedure. Care should be taken not to ever use the endodontic files in dry canals.

13.5 Learning Objectives

The reader should be able to understand the following.

• The significance of proper reading of the preoperative radiograph.
• The importance of using endodontic ultrasonic tips to modify the endodontic access cavity.
• Emphasis on achieving straight line access cannot be ignored.
• The role of irrigants for disinfecting the root canal system.
• Using flexible TruNatomy irrigation needles helps the needle to adapt to the shape and curvature of the root canal.
• The importance of incorporating the whole root canal system in the disinfection process during primary root canal treatment.
• How to decide clinically which instrument is to be used for a particular step during an primary endodontic treatment.
• The importance of using the right materials to initiate body healing.
• The concepts of understanding the prognosis of the tooth and trying to save the tooth instead of straight away extracting it.