My published article about a complex root canal procedure

Posted by on Apr 26, 2013

The successful treatment of a tooth with multiple perforations and incomplete biomechanical preparation and short obturation: A 3-year follow-up

 

ABSTRACT

Several factors contribute to the success of any endodontic procedure. Some authors say success is based on good endodontic access, correct cleaning and shaping, and adequate obturation. Sound knowledge of anatomy also plays a major role in successful treatments, especially when there are variations to the norm. Pathologic and iatrogenic conditions also factors in the success of endodontic treatment; wherein the prognosis is usually better when there are no presence of either condition. Factors that influence success and guidelines that indicate success are different.

Perforations and ledges are iatrogenic conditions that add complication to root canal treatment. They need to be addressed so that proper treatment can be done. The use of modern materials and precise techniques usually yield good prognosis.

In this case report, a lower first molar with multiple iatrogenic furcal perforations and an apical pathosis is presented. The treatment involved the repair of the perforation using MTA and continuation of root canal treatment. Although the biomechanical preparation was not completed due to ledges and the obturation was short, the three-year follow-up showed complete healing of the periapex and no symptoms of disease in the furcation area.

INTRODUCTION

According to the European Society of Endodontology, The definition of endodontic success is: “Clinical symptoms originating from an endodontically-induced apical periodontitis should neither persist nor develop after RCT and the contours of the PDL space around the root should radiographically be normal.” Success would be indicated by relief from symptoms, healing of sinus tracts and reduction or complete resolution of periapical radiolucency. If a root-filled tooth is functional, clinically symptomless and has no evidence of disease radiographically, then treatment can be considered a success (12). The factors that influence success and the guidelines that define success are different.

The factors that influence success, such as good endodontic access, correct cleaning and shaping, and adequate obturation does not necessarily guarentee successful outcomes of endodontic cases. There are those cases that incorporate all the factors but still fail; on the other hand, there are those cases that doesn’t adhere to these factors but end up being successful.

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One of the initial procedures performed during a routine root canal treatment is access cavity preparation (1,2). Good knowledge of the anatomy of the tooth and precise instrumentation is key to a good access cavity. Without these, it is possible for a dentist to perforate the tooth during access cavity preparation. Perforations can happen anywhere in the tooth; in the crown, root, and furcal areas of multi-rooted teeth. Usually, teeth with different anatomy and angulation are the ones that are easy to perforate during access cavity preparation (2). The prognosis of a tooth with a perforation also depends on the level, location, size and time factor of the perforation injury (2). Excellent management of a perforation involves good diagnosis, detection, vision, elimination of bacteria, sealing of the perforation, and restoration of lost tooth structure. The use of modern devices such as electronic apex locators and dental microscopes and good perforation repair materials such as mineral trioxide aggregate (MTA) and reinforced zinc oxide eugenol cement (Super EBA) have been found to improve the treatment outcome. (2, 3) MTA has been found superior to other materials in terms of sealability and the biocompatibility. It has also been found out to be structurally stable and strong enough to replace hard tissues. (4,5) In this case report, a tooth with multiple perforations was successfully repaired by the use of MTA and healing of the periapex was monitored in a span of 3 years.

Case Report

A 26 year old female patient was referred to our office. She had a tooth ache a week prior to visiting her family dentist. The family dentist attempted to do access cavity preparation. The dentist decided to refer it to us because of a perforation. After two days, the patient was brought to our clinic. Evident in the initial radiograph (Fig. 1a) were gouging in the mesial and distal orifice area. In the distal, the gouging seems to extend near the CEJ. There is also widening of the periodontal ligament space along the mesial and distal roots. The tooth was positive to percussion and palpation. There was a 4 mm probing depth in the disto-buccal area while the rest of the marginal margin had normal probing depths. There was no mobility. The tooth was diagnosed with a necrotic pulp. Upon removing the temporary filling, several gouges to the floor of the pulp chamber was seen. The gouges appear to have been caused by large diamond burs. (Fig 1b) An infra-alveolar nerve block was performed. The tooth was isolated with rubber dam and initially explored with an endodontic explorer and small K-files size 10. 2.5% sodium hypochlorite was used to copiously irrigate the chamber and the canals throughout the whole procedure. Three root canals were found: mesiobuccal, mesiolingual and distal root canals. These were confirmed with radiographs and an electronic apex locator (Fig 2). Upon exploring the canals, ledges were encountered on all three canals. The ledges on the distal and mesiolingual root canals was fixed but the one on the mesio-buccal were beyond resolve. Knowing the fact that incomplete shaping and cleaning of the canal may lead to failure, the prognosis was discussed with the patient. The patient understood that there is still a chance for success and urged that the treatment be continued. After completely mapping the floor of the pulp chamber for possible root canals and other perforations, a treatment plan was formulated and discussed thoroughly with the patient. The treatment plan was to repair the perforations and perform a standard root canal treatment afterwards. The root canals were initially filed with size 10 K-files until #20 K-files (Dentsply, Maillefer, Switzerland). The Two large furcal perforations near the mesio-buccal root canal orifice and one cervical perforation in the distal wall of the crown were found. These were confirmed by both radiograph and an electronic apex locator (Fig. 1c). Bleeding was controlled with Viscostat (Ultradent Products Inc., Utah), a hemostatic gel composed of 20% Ferric Sulfate. Three root canals were found: mesiobuccal, mesiolingual and distal root canals. These were confirmed with radiographs and an electronic apex locator (Fig 2). Upon exploring the canals, ledges were encountered on all three canals. The ledges on the distal and mesiolingual root canals was fixed but the one on the mesio-buccal were beyond resolve. Knowing the fact that incomplete shaping and cleaning of the canal may lead to failure, the prognosis was discussed with the patient. The patient understood that there is still a chance for success and urged that the treatment be continued. After completely mapping the floor of the pulp chamber for possible root canals and other perforations, a treatment plan was formulated and discussed thoroughly with the patient. The treatment plan was to repair the perforations and perform a standard root canal treatment afterwards. The root canals were initially filed with size 10 K-files until #20 K-files (Dentsply, Maillefer, Switzerland). The root canals were then shaped with an S1 and S2 ProTaper shaper files and finished with an F1, F2, and F3 Protaper rotary files respectively (Dentsply, Maillefer, Switzerland). After the shaping and cleaning, the canals were blocked with #80 gutta-percha cones (Fig 3). After which, ProRoot MTA (Maillefer, Dentsply, Switzerland) was packed inside the pulp chamber to seal the perforations and serve as a restoration at those damaged sites. (Fig 4) After 2 weeks, the patient was recalled. The symptoms were gone and the tooth was not tender to percussion anymore. The root canals were obturated by lateral condensation technique using gutta-percha and AH Plus root canal sealer (Dentsply, Maillefet, Switzerland). Glass ionomer cement was placed as a base filling material and IRM was used as a temporary restoration. The patient was referred back to her family dentist for a final composite inlay restoration. The patient was instructed to come back after 6 months for a routine recall but she was not able to return until after 3 years. The patient was recalled after 3 years and the tooth was asymptotic and functional. A radiograph was taken to check the state of the periodontium. The radiolucency previously present in the distal root apex has completely healed and there was no more widening of the periodontal ligament space. The bone in the furcation area seems to be healthy (Fig 5).

Discussion

The perforations presented in this case are of two kinds. One is a furcal perforation and the other a cervical perforation. Furcal perforations and cervical perforations are of the same level and thus have similar considerations. Perforations at the level of the furcation and CEJ threaten the sulcular attachment and pose a more challenging case than more apically positioned perforation (2). Prognosis is also less favorable as the perforations are closer to the crown. The size and number of perforations also lead to a less favorable prognosis. In the case presented here, there were multiple perforations at the level of the furcation and CEJ thus yielding a guarded prognosis. The furcal perforation appears to have been caused by a round bur as evident in the shape of the damage in the floor of the pulp chamber. Detection of perforations is done by the use of radiographs, microscopes, paper points and electronic apex locators. In the case provided, radiographs, paper points and electronic apex locators were used to detect and confirm the location and extent of the perforation. Multiple perforations close to each other pose a significant difficulty in detection with the use of just one method – specifically the use of an apex locator because false readings can be acquired. In this case, multiple methods and strict control of hemostasis were needed and used to correctly detect and treat the perforation (10). The management of the perforation presented here involved prompt action. This is because time is very critical to the prognosis of perforation cases. Regardless of the cause, a perforation should be repaired as soon as possible to prevent further loss of attachment and sulcular breakdown. Chronic perforations usually needs surgical correction and guided tissue regeneration procedures. Prognosis also deteriorates as damage to to time progresses (2). MTA is a good repair material in cases such as this because of its properties. Its sealability and biocompatibility have been the topic of many studies. It also has numerous good case reports wherein it was used for perforation repair, retrograde filling and apexification material. In all these procedures, it is in direct contact with the periodontal tissue and hard tooth structure. (4, 5, 6) Only the apex of the distal root canal showed periodonal ligament space widening. It may be possible that the mesio-buccal root canal were not infected and that may explain why the incomplete BMP and short obturation did not incite inflammatory processes. Healing at the apex of the distal and mesio-lingual root canals followed after a complete BMP and adequate obturation. A study by H.A. Ray and M. Trope explains the success of root canal treatment in relation to the technical quality of root filling. They concluded that the technical quality of the coronal restoration was significantly more important than the technical quality of the endodontic treatment for periodontal health (9). This means that the coronal seal the tooth in this case will be a major factor in its survivability. Hemostasis in this case was achieved with the use of Viscostat (Ultradent Products Inc., Utah). This material produces very little coagulate due to its gelatinous consistency as compared with those which has liquid consistency. There are studies that support its usage in composite bonded restoration and endodontic surgery. These studies proved that it didn’t affect bond strength of composite restoration due to its coagulate. Although no study about its effect on the adhesion of MTA to dentinal walls, we can assume that MTA will have a better capacity for adhesion to the dentin wall even if there is presence of moisture (7,8,9). In this case, the guidelines that lead to success were not fully met but the factors that indicate success can be observed. The tooth was free of pain, there is no presence of disease clinically and radiographically and the tooth is functioning properly. The three year recall confirmed the success of the treatment. In a series of cases reported by S. Szajkis and M. Tagger, they observed periapical healing in spite of incomplete root canal debridement and filling. They have long-term radiographic proof that healing has maintained itself. They have explained two mechanisms that may explain their findings but still recommended further research in periapical biology (13) Although the principles of proper root canal treatment were not followed due to uncontrollable circumstances, proper guidelines to success should still be strictly followed as much as possible. In this case report, a tooth with multiple perforations and apical pathosis was successfully treated. Despite numerous challenges and shortcomings (ledges, incomplete BMP, short obturation), the tooth is currently retained in its socket and is functioning properly without any signs of infection. Further evaluation of the tooth should be performed after 5 and 10 years if possible.

ABOUT THE AUTHOR

Dr. Joselito Rafael A. Buenazedacruz is a student in the University of the East Post-graduate School taking up his Masters in the Science of Dentistry specializing in Endodontics. He earned his DMD degree in 2006 in the same university.

 

 

References

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