Non-surgical Root Canal Treatment Case IX:
Maxillary Molar / Difficult Anatomy (Dilacerated Molar Case Management)
Priya S. Chand and Jeffrey Albert
“I have severe pain to cold on my upper left tooth. It hurts all of the time.”
The patient (Pt) was a 57-year-old Caucasian male. Blood pressure (BP) was 126/77 mmHg, pulse 64 beats per minute (BPM), respiratory rate (RR) 16 breaths per minute. Pt reported with a history of hypertension, arthritis, and no known drug allergies (NKDA). He managed his hypertension by regulating his diet and regular exercise. He also took metoprolol tartrate 100 mg daily for hypertension and ibuprofen 400 mg as needed for arthritic discomfort. The Pt denied respiratory, hematological, gastrointestinal, nervous system, or genitourinary disorders.
The Pt was American Society of Anesthiesiologists Physical Status Scale (ASA) Class II. There were no contraindications to routine dental treatment (Tx).
The Pt was referred by his dentist for root canal treatment (RCT) on tooth #15. Three days prior, the dentist had placed a temporary (temp) bridge on abutments on teeth #12, #13, and #15 with pontic on tooth #14. Following the placement, the Pt had been experiencing severe, spontaneous, and cold drink pain in the upper left posterior quadrant. He reported that the teeth were asymptomatic prior to placing the temp bridge. The new bridge was being fabricated to replace an older faulty bridge that had recurrent decay on abutment on tooth #15. Tooth #14 was extracted over fifteen years ago. The Pt went for routine periodontal maintenance and yearly dental examinations. He had several crowns and dental restorations throughout the mouth.
Extra-oral Examination (EOE)
The face was bilaterally symmetrical. Lymph nodes were not tender or enlarged. The oral cancer screening was negative.
Intra-oral Examination (IOE)
Teeth #12, #13, and #15 presented as abutments with a temp bridge. Tooth #14 was not present and a temp pontic was contacting the gingiva. The temp bridge had overhanging margins on all three teeth. Underneath the bridge, tooth #15 exhibited a mesio-occlusal (MO) composite build-up with good marginal integrity. Teeth #12 and #13 did not have any restorations or caries present. Periodontal probings for teeth #12, #13, and #15 were 1–3 mm circumferentially. The temp bridge was removed and an endodontic examination was performed for teeth #12, #13, #15, and #19.
EPT: Electric pulp test; WNL: within normal limits; L: Lingering; +: Positive response to percussion, EPT, or bite.
One digital periapical radiograph (PAX) was taken (Figure 15.1). Normal trabecular pattern of bone was observed. The PAX showed teeth #13, #15, and part of tooth #12. Periodontal bone evaluation indicated mild bone loss. Tooth #15 revealed a radiopaque coronal restoration with an underlying more radiopaque restoration extending close to the pulp chamber. The pulp chamber appeared to be receded and the root canals were not easily visible. The mesiobuccal (MB) and distobuccal (DB) roots were dilacerated. The MB root displayed a sharp, almost 90° distal (D) curve in the middle third of the root. The DB root sharply curved to the D. The DB and palatal (P) root apices showed a thickened lamina dura, while the apical extent of the MB root was difficult to distinguish on the PAX. Tooth #14 was absent, with a radiopaque restoration attached to teeth #13 and #15. Tooth #13 showed a radiopaque coronal restoration, a receded pulp chamber, and an intact lamina dura apically. Tooth #12 was partially shown with a radiopaque coronal restoration and an intact lamina dura. Radiopacities were observed in the maxillary sinus apical to tooth #15.
Symptomatic Irreversible Pulpitis, tooth #15
Symptomatic Apical Periodontitis, tooth #15
Definitive:Non-surgical root canal treatment
Extraction and replacement prosthesis or no treatment with potential consequences
Chamber retained core and cuspal coverage: Tx planned as a bridge abutment
First visit (Day 1): Options were presented to the Pt with both pros and cons of Tx. The Pt opted and consented for RCT on tooth #15. The temp bridge was removed prior to testing the teeth. 20% benzocaine topical anesthetic was placed and 68 mg of lidocaine (lido) with 0.034 mg epinephrine (epi) was administered by infiltration injection at the base of the buccal (B) vestibule, apical to tooth #15. A palatal infiltration injection was given. The rubber dam (RD) was placed on tooth #15 and an access cavity was prepared with a #2 carbide round bur. Examination of the pulp chamber with the surgical operating microscope revealed a heavily bleeding pulp with several pulp stones. The pulp stones were removed with ultrasonic vibration and an endodontic explorer. The MB and P canals were located, but the calcified DB and MB2 canals were not visualized with the microscope on the pulpal floor. An LN™ bur (Dentsply Sirona, Tulsa, OK, USA) was used to remove the calcified tissue over the DB canal and trough the area of the MB2 canal. The DB canal was located 2 mm apical to the pulpal floor in the DB root. The MB2 canal could not be located. Gates-Glidden burs #2 and #3 were used to flare the coronal third of the root canals. Heavy canal calcifications were encountered in the MB and DB canals. After an hour of attempting to negotiate the three canals, the Pt showed signs of tiring. Working lengths (WL) were determined by the electronic apex locator (EAL) for the MB, DB, and P canals. The DB and P canals were instrumented to a size #25 K-file. The highly curved and calcified MB canal could only be cleaned and shaped to a size #15 K-file, needing to continually recapitulate to smaller files in order to maintain a clear canal path to the apex. The canals were irrigated with 10 ml of 5.25% sodium hypochlorite (NaOCl), 8 ml of 17% ethylenediaminetetraacetic acid (EDTA), and RC-Prep® (Premier Dental Products, Morristown, PA, USA) was used for file lubrication. Paper points were used to dry the canals and calcium hydroxide (Ca(OH)2) paste was placed with a size #10 K-file to working length in all three canals. A dry cotton pellet was placed into the pulp chamber. The access cavity was sealed with Cavit™ G (3M, Two Harbors, MN, USA) and the temp bridge was cemented with Temp-Bond™ (Kerr, Romulus, MI, USA). The occlusion was verified with an articulating paper. The Pt felt well at dismissal and was instructed to take 600 mg ibuprofen every 6 hours as needed for discomfort. The Pt was scheduled to continue treatment in one week.
Second visit (Day 8): BP 122/72 mmHg, pulse 66 BPM. The Pt was asymptomatic (ASX). 20% benzocaine topical anesthetic was placed and 34 mg of lido with 0.017 mg epi was administered by infiltration injection at the base of the B vestibule, apical to tooth #15. A palatal infiltration injection was given. The temp bridge was removed and RCT on tooth #15 was continued under RD isolation. After tooth # 15 was re-accessed, WLs were confirmed by the EAL. Continued troughing in the area of the MB2 canal produced a stick with the endodontic explorer. The MB2 canal was calcified and curved. After 45 minutes of Tx, the MB and MB2 canals could only be negotiated to WL with a size #20 K-file. The MB and MB2 canals required additional flaring of the coronal third and continual recapitulation to smaller files in order to maintain a clear canal path to the apex. The DB and P canals were both cleaned and shaped to WL with a Vortex Blue® Nickel Titanium (NiTi) rotary files (Dentsply Sirona, Johnson City, TN, USA), size #30, .04 taper using a crown-down technique. Prior to using the rotary files a #25 K-file was used to verify the WLs with the EAL. The canals were irrigated with 10 ml of 5.25% NaOCl, 6 ml of 17% EDTA, and RC-Prep® was used for file lubrication. A final irrigation of 3 ml of 2% chlorhexidine (CHX) was performed. The Pt was tiring and a decision was made to complete the DB and P canals. Paper points were used to dry the canals and a cone fit PAX (Figure 15.2) was taken. (Note the file placed in the MB canal to confirm the working length). The radiograph showed a radiolucent area extending from the inferior border of the maxillary sinus to the coronal third of the root of tooth #13. The tooth was ASX and tested WNL to the cold test at the initial appointment. The periodontal probings were confirmed for teeth #12, #13, and #15 at 1–3mm circumferentially. The general dentist was notified and advised to have an oral surgeon review the radiograph and evaluate the Pt prior to placing the bridge. Obturation of the DB and P canals was completed by warm vertical compaction, using AH Plus® Root Canal Sealer (Dentsply Sirona, Konstanz, Germany) to coat the gutta-percha (GP) cones and canal walls. A heat source and pluggers were used to heat and compact the GP. The remaining canal space was backfilled with warm GP to the level of the canal orifices. Ca(OH)2 paste was placed with a size #10 K-file to working length in the MB and MB2 canals. A dry cotton pellet was placed in the pulp chamber. The access cavity was sealed with CavitTM G and the temp bridge was cemented with Temp-BondTM. The occlusion was verified with an articulating paper. The Pt felt well at dismissal and postoperative instructions (POI) were reviewed. A one-week completion appointment for the MB and MB2 canals was scheduled.
Third visit (Day 14): BP 118/74 mmHg, pulse 62 BPM. The Pt was ASX. Tooth #13 tested WNL to the cold test. 20% benzocaine topical anesthetic was placed and 34 mg of lido with 0.017 mg epi was administered by infiltration injection at the base of B vestibule, apical to tooth #15. A palatal infiltration injection was given. The temp bridge was removed and RCT of tooth #15 was completed under rubber dam isolation (RDI). Tooth #15 was re-accessed, and WLs for the MB and MB2 canals were confirmed by the EAL. The canals were instrumented to WL to a #25 K-file. The MB and MB2 canals were cleaned and shaped with Vortex Blue® Nickel Titanium (NiTi) rotary files (Dentsply Sirona, Johnson City, TN, USA) using a crown-down technique to a size #30, .04 taper and size #25, .04 taper, respectively. The canals were irrigated with 6 ml of 5.25% NaOCl, 4 ml of 17% EDTA, and RC-Prep® was used for file lubrication. A final irrigation of 3 ml of 2% CHX was performed. Paper points were used to dry the canals and a cone fit radiograph was taken. The MB and MB2 canals joined in the apical 1–2 mm of the M root. Obturation of the canals were completed by warm vertical compaction using the same protocol as described in the previous visit. The pulp chamber was cleaned with an alcohol cotton pellet. A dry cotton pellet was placed in the pulp chamber and the access cavity was sealed with CavitTM G. The temp bridge was cemented with Temp-BondTM and the occlusion was verified with articulating paper. Two final digital PAX (Figures 15.3 and 15.4) were taken showing well obturated canals to within 0.5 mm of the radiographic apices. The MB1 and MB2 canals joined in the apical 1–2 mm. The radiolucency mentioned during the previous visit, cone fit PAX, was not as evident in the two final PAX. The dentist was advised of the radiolucent area in close proximity to the sinus. The Pt felt well at dismissal and POI were reviewed. The Pt scheduled an appointment to return to his dentist in the next two weeks to proceed with the fabrication of the new bridge for teeth #12 to #15.
Working length, apical size, and obturation technique
|Canal||Working Length||Apical Size, Taper||Obturating Materials and Technique|
|MB||17.0 mm||30, .04||GP and AH Plus® sealer,
Warm vertical compaction
|MB2||18.0 mm||25, .04||GP and AH Plus® sealer,
Warm vertical compaction
|DB||19.0 mm||30, .04||GP and AH Plus® sealer,
Warm vertical compaction
|P||19.5 mm||30, .04||GP and AH Plus® sealer,
Warm vertical compaction
Fourth visit (1-year follow-up): Clinical examination; BP 128/83 mmHg; pulse 69 BPM. There were no changes in the medical Hx. EOE showed bilateral symmetry of the face. Lymph nodes were not tender or enlarged. IOE was unremarkable. The oral cancer screening was negative.
The Pt was ASX. Teeth #12, #13, and #15 were WNL for percussion, palpation, and bite. Teeth #12 and #13 were WNL to the cold test. The dental Hx included a new bridge on abutment teeth #12, #13, and #15 with pontic tooth #14. Periodontal probings were 2–3 mm circumferentially for teeth #12 to #15. The gingiva appeared pink and healthy. The occlusion was WNL, verified with articulating paper. The bridge margins appeared to be well sealed as inspected with the dental explorer.
Radiographic examination: two digital PAX were taken. PAX (Figure 15.5) showed an intact lamina dura apically on the DB root of tooth #15. The root canals were well obturated to within 0.5 mm of the radiographic apices. The MB1 and MB2 canals joined in the apical 1–2 mm of the root. PAX (Figure 15.6 ) revealed a second angle of tooth #15 and the DB root apex was not shown. The radiolucent area in the proximity of the sinus was not clearly visible. The Pt did not see an oral surgeon as advised.