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Hemisection as a Conservative Management Strategy for Instrument Separation Followed by Prosthetic Rehabilitation
* Corresponding author: Dr. Shazeena Qaiser, Dr. Qaiser’s Dental Clinic, Sanatnagar, Srinagar 190005, Jammu and Kashmir, India. shazeena.q18@gmail.com
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Received: ,
Accepted: ,
How to cite this article: Qaiser S, Shroff R, Abhishek MA, Gupta S, Shetty C. Hemisection as a Conservative Management Strategy for Instrument Separation Followed by Prosthetic Rehabilitation. J Health Allied Sci NU. doi: 10.25259/JHS-2024-8-3-(1498)
Abstract
Continual advances in the field of dentistry, along with a growing desire among patients to preserve their dentition, have resulted in the management of teeth that would have otherwise been extracted. Various procedural errors, like instrument separation, could be a reason for endodontic failure and/or the extraction of teeth where the retrieval is not possible. However, with newer approaches, only the diseased portion of the tooth can be removed after the non-surgical root canal treatment, followed by a fixed prosthesis to reinforce the remaining component of the tooth to neighbouring teeth. Although being an arduous task, this treatment can be completed and maintained effectively. This series of case reports illustrates the two scenarios where hemisection was used as a treatment strategy, followed by prosthetic rehabilitation.
Keywords
Endodontic therapy
Fixed partial
Hemisection
Instrument separation
Prosthetic rehabilitation
INTRODUCTION
A dental practitioner who has worked specifically in the field of endodontics has experienced an array of emotions, from the exhilaration of the fill to the dismay of procedural accidents, including intracanal instrument separation.[1] The risk of instrument breakage is inevitably present during the root canal preparation procedures, and its prevalence varies between 2% to 6% of all cases evaluated.[2] Maximum of the stainless-steel instruments fracture by extreme torque, and NiTi rotary files typically fail due to torsional stress and cyclic loading.[3] The separated instrument may hamper the proper biomechanical preparation, thereby influencing the treatment outcome. In addition, Fox et al. found that most of the failed cases were linked to the intracanal broken instrument.[4] If a broken instrument is kept, corrosion products may form in the canal, resulting in endodontic failure. Hence, an attempt to retrieve the instrument is the first choice; however, if the retrieval is not possible, considering the separated instrument might affect the prognosis, hemisection would be an alternative treatment as compared to the conventional extraction. Hemisection is a surgical procedure specially introduced as a treatment alternative for pathologic or iatrogenic entities. It is the process of dividing a mandibular molar at the junction of the furcation into two halves and then removing the diseased root and its coronal part.[5–7]
This article presents two case reports where hemisection was used as an alternative treatment for the preservation of the tooth, followed by the prosthesis.
CASE REPORT
Case 1
Patient information
A 22-year-old male patient reported to the department with the chief complaint of pain in the lower right back tooth region for 2 months. The pain was mild and intermittent, which intensified on chewing. He had experienced pain a few days after undergoing endodontic therapy (incomplete) in relation to 46.
Clinical findings
Intraoral examination revealed a temporary/provisional restoration in relation to 46 with no other detectable abnormality [Figure 1a]. A percussion test of the affected tooth revealed a positive response. Radiographical examination revealed a radio-opaque material within the portion of mesial and distal canals, an instrument fragment in the apical third of the mesial root (∼6 mm), and inter-radicular bone loss with furcal radiolucency. Also, the bony trabeculae in the distal root were intact with normal radiographic findings [Figure 1b].
-g1.png)
- Clinical and radiographic images of hemisection of right mandibular first molar. (a) Preoperative clinical photograph, (b) Preoperative Radiograph, (c) After biomechanical preparation, (d) Obturation completed wet distal root, (e) Restored with GIC, (f) Sectioning done, (g) Hemisection done, (h) Mesial root removed, (i) Overextended broken instrument 2mm beyond the apex, (j) Hemisection verified radiographically, (k) Two single interrupted sutures given, (l) Healing after 2 months, (m) Fixed prosthesis wrt 35,36, (n) Radiographic verification, (o) Follow-up radiograph.
Diagnostic assessment
Based on history and clinical and radiographic examination, a diagnosis of symptomatic apical periodontitis was made, and according to American Association of Endodontists (2013), this case would fall under the category of previously initiated therapy. Since the file was separated in the apical third, and there was a slight curvature noticed in the apical third, retrieval was not attempted. Hemisection could be a choice due to some specific indications given by Weine, i.e., bony support of the retained root was relatively stronger, an irretrievable instrument fragment, no sign of fusion of the root, and no signs of chronic periodontitis. Therefore, the patient was made aware of the state and long-term success of the treated tooth, along with treatment alternatives such as hemisection, extraction, and dental implant placement. The patient, who was still quite young, did not want to lose his tooth, and his financial situation did not support the choice of a dental implant. He, therefore, selected hemisection over other treatment options, followed by a fixed dental prosthesis.
Therapeutic intervention
So, the treatment plan was divided into 4 phases: 1. Endodontic Phase- NSRCT was performed, 2. Periodontic Phase- hemisection, debridement, and 3. Prosthodontic Phase- tooth preparation followed by the final prosthesis.
In the first appointment, provisional restoration was removed, and access was refined [Figure 1c]. Working length determination was done for the distal root using Root ZX J (0.5 mm from the perceivable apex). Biomechanical shaping and cleaning were done, with rotary files (ProTaper Next, Dentsply Maillefer) up to file size F4, under passive mechanical irrigation with saline and 4% w/v sodium hypochlorite solution, a calcium hydroxide interappointment intracanal dressing was given for 2 weeks. In the second appointment, single cone obturation was completed using F4 gutta-percha points and Seal Apex sealer [Figure 1d]. In the next appointment, an inferior alveolar nerve block was given, and the tooth was visualised both clinically and radiographically to check for the approximate sectioning position; the root junction was identified to preserve the distal root and furcation anatomy. The occlusal table was reduced before resection to disperse the functional forces better. A crevicular incision was given beginning from the first premolar to the second molar after suitable local anaesthesia and tissues were reflected buccally and lingually to enhance visualisation [Figure 1e]. Using a surgical length straight fissure, the sectioning was done in a brushing stroke with adequate coolant [Figure 1f]. Luxation of the mesial segment was performed, and during the removal of the mesial root, great care was taken to avoid traumatising the bone or adjacent tooth. The mesial root was extracted without any trauma, and the socket was irrigated adequately with normal saline and subsequently filed with a bone file to remove bony chips and irregularities. [Figure 1g and 1h]. The apical portion of the extracted root showed an overextended broken instrument [Figure 1i]. The process and completeness of tooth resection were verified radiographically and clinically [Figure 1j]. The flap was approximated, and simple interrupted sutures were placed, using Vicryl (3-0) suture material (polyglactin) [Figure 1k]. The occlusion was relieved and readjusted to redirect the forces along the long axis of the distal root, and the patient was given postoperative instructions. Because hemisected teeth tend to fail due to radicular fracture, it was critical to reinforce them sufficiently with an extra-coronal restoration, which was done after adequate healing was complete. Suture removal was done after 1 week and kept under follow-up and recalled after 2 months [Figure 1l]. At follow-up appointments, the healing of the treated tooth was uneventful. The prosthetic phase of therapy was started, whereby the distal part of the first permanent molar and second premolar was prepared, followed by placement of the porcelain-fused-to-metal prosthesis [Figure 1m and 1n].
-g2.png)
- Clinical and radiographic images of hemisection of left mandibular first molar. (a) Preoperative Radiograph, (b) Obturation completed, restored with GIC, (c) Sectioning done, (d) Verified radiographically, (e) Hemisection done, (f) Mesial root removed, overextended broken instrument 1.5 mm beyond the apex, (g) Hemisection verified radiographically, (h) Tooth preparation done wrt 36 (distal half), (i) Fixed prosthesis wrt 36 along with distal rest on 35, (j) Follow- up radiograph after 1 month. Silver patch represents metal ceramic prosthesis constructed to rehabilitate the tooth of interest.
Follow-up and outcomes
Radiographic findings revealed the formation of bone in the extraction socket. Radiographic success observed at six months of follow-up showed the presence of a healthy periodontal ligament and bone formation at the extraction site [Figure 1o].
Case 2
Patient information
A 25-year-old male patient reported to the department with the chief complaint of pain which wain the lower left back tooth region for 10 days. The pain was dull, intermittent, and exacerbated by chewing.
Clinical findings
Clinical examination revealed a provisional restoration in relation to 36, which was tender on percussion. Radiographic examination revealed a separated instrument in the apical third of the mesial root (∼8mm) [Figure 2a].
Diagnostic assessment
Based on history and clinical and radiographic examination, symptomatic apical periodontitis was diagnosed, and according to AAE (2013), this case would also fall under the category of Previously Initiated Therapy. Instrument retrieval was not attempted since it was in the apical third. Hence, hemisection was chosen as a treatment alternative after explaining to the patient and obtaining their consent.
Therapeutic intervention
The procedure was the same as explained in the previous case [Figure 2b-g]. However, in this case, the tooth preparation of the distal portion of the first permanent molar was completed, along with a slot preparation on the distal aspect of the second premolar was made to be used as an occlusal rest [Figure 2h], followed by placement of the porcelain-fused-to-metal prosthesis [Figure 2i].
Follow-up and outcomes
This was followed up after three months, where the radiographs revealed satisfactory bone formation in the extraction socket, and radiographic evaluation at six months indicated uneventful healing with healthy periodontal ligament and adequate bone formation [Figure 2j].
DISCUSSION
The treatment plan of hemisection should be finalised after a thorough periodontal, prosthodontic, and endodontic assessment. The extent and pattern of bone loss, root length and shape, root divergence, ability to reverse the osseous defects and post-endodontic restoration should always be considered.[8] All of these factors were taken into consideration for the above cases. Hemisection is a good and physiologically economic alternative treatment plan with a good prognosis, according to Buhler et al. (1994), and should be considered before every molar extraction.[9] Removable partial dentures, fixed partial dentures, and dental implants are all alternatives for replacing badly damaged and probably irreversible teeth. It should be a guiding concept to try to preserve what is already there.[10] When a hemisection is used to preserve a damaged tooth, the prognosis is comparable to that of any other tooth treated with endodontics. Intriguing demographic findings were shown by Yuh et al. after retrospectively analysing the success rates of a significant number of root-resected molars. For molars with their roots removed, a survival rate of 91.1 per cent was found.[11] During a ten-year follow-up, Carnevale et al. found that patients who had their furcated molars treated with hemisection had a survival rate of around 93 per cent.[12]
CONCLUSION
The prognosis of a compromised tooth maintained through hemisection is comparable to that of any other tooth receiving endodontic therapy. However, proper case selection, thorough planning, and a scheduled multidisciplinary approach need to be taken into consideration for a successful outcome.
Ethical approval
Institutional Review Board approval is not required.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
Use of artificial intelligence (AI)-assisted technology for manuscript preparation
The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI.
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