AUTHORS: Dr. Pooja Kakkar, Dr. Anant Singh.
Sardar Patel Post Graduate Institute of Dental And Medical Sciences, Rai Bareilly Road, Lucknow-226025
ABSTRACT
Mandibular premolar teeth show extreme variations in root canal morphology. Second premolars usually exhibit the basic one root and one canal anatomy. The occurrence of mesial and distal roots has not been commonly reported in literature. This article reports a case of successful nonsurgical endodontic management of bilateral mandibular second premolars with two separate roots with an uncommon mesial and distal morphological location confirmed with the help of spiral computed tomography and to review those factors which will assist the clinician in the detection and subsequent treatment of multiple canals in mandibular premolars.
INTRODUCTION
The main objective of endodontic therapy is thorough mechanical and chemical debridement of the entire root canal followed by a three dimensional obturation with an inert filling material and final restoration thereby providing a coronal seal 1.
Weine has cited the major causes of endodontic treatment failure are incorrect canal instrumentation, incomplete obturation and untreated major canals2.Failure to recognise the presence of an additional root and or root canal in any tooth may result in unsuccessful treatment and may be the origin of acute flare ups during and after treatment3.
Because of the variations in canal anatomy, the mandibular premolars as a group are the most difficult teeth to treat endodontically and hence they have a high flare up and failure rate 4.Washington study assessing the results of endodontic therapy had a failure rate of 11.45% in in Mandibular 1st premolars and 4.54%failure in mandibular 2nd premolars 5.A possible explanation may be the extreme variations in root canal morphology of mandibular premolar teeth compared with the standard description of one root, one canal found in text of dental anatomy 6. Another important point that should be emphasised is the anatomic position of mental foramen and neurovascular structures that pass through it in close proximity to the apices of mandibular premolars. There are reports of flare-ups in mandibular premolars with associated paraesthesia of the inferior alveolar and mental nerves because of missed root canals 7.
Therefore, awareness and understanding of the presence of unusual external and internal root canal morphology largely contributes to the successful outcome of the root canal treatment.
The purpose of this article is to report a case of successful nonsurgical endodontic management of bilateral mandibular second premolars with uncommon root morphology presenting with two separate roots located mesially and distally and to review those factors which will assist the clinician in the detection and subsequent treatment of multiple canals in mandibular premolars.
CASE REPORT
A twenty eight year old female patient of Indian descent was referred to the Post Graduate Department of Conservative Dentistry and Endodontics with chief complaint of intermittent pain over three months in relation to lower left and right mandibular premolar region. Patient also complained of episodes of sensitivity to hot and cold in the involved teeth. Medical history was non-contributory. Dental history revealed that she had undergone root canal treatment of maxillary left first premolar and bilateral extraction of mandibular first molars .
On clinical examination, patient’s oral hygiene was found to be moderate. Distal proximal caries was observed in both the mandibular first premolars . Deep distal proximal carious lesion was noted in the left and right mandibular second premolars and both teeth were tender on percussion. Vitality tests using thermal and electric pulp tests (Sybron Endo,USA) revealed a rapid lingering painful response. There was no evidence of swelling or sinus tract.
At first glance, the preoperative periapical radiographic examination showed presence of two roots bilaterally in mandibular second premolars (Figure1A,1B). A second radiograph with more mesial angulation was taken for a clear view to exclude the presence of third root. Two roots were found to be distinguished as mesial and distal.
Based on clinical and radiographic evidences a probable diagnosis of acute pulpitis with apical periodontitis was made.
Access was gained to the pulp chamber after administration of local anaesthesia with2% lignocaine with adrenaline (Septodont, France) under rubber dam isolation. To gain sufficient access to the canals, the conventional access opening was modified into one that was wider mesio-distally. Orifice location was not easy as the coronal pulp chamber was usually long and the separation of roots was from the middle third of the root. The two canal orifices were located under magnification using surgical operating microscope (Zeiss,Germany) and patency was ascertained using a small size 10 K file. The working length radiograph was taken.(Figure 2A,2B).
Gates Glidden drill (Dentsply, Maillifer, USA) with brushing motion in a crown down fashion was used to enlarge the orifice to achieve a straight line access to the apex. The canals were cleaned and shaped with Protaper files(Dentsply, Maillifer, USA) with sequentially irrigated using EDTA (Glyde File Prep. Dentsply, Maillifer, USA) and 3% sodium hypochlorite and dried with paper points.
Cotton was placed in the pulp chamber and cavit (3M ESPE) was used to close the access cavity. At the second appointment canals were rinsed with 3% sodium hypochlorite followed by a final rinse with saline, dried and obturated with F2 Protaper gutta perch points (Dentsply,Maillifer, USA) using zinc oxide eugenol and sealer (Septodont,France). The access cavity was filled with silver amalgam (DPI, India) (Figure 3A,3B).
To confirm the complex root canal anatomy of the tooth spiral CT scan (Siemens,Germany) using dental software Dentascan was planned after obturation and informed consent of the patient was obtained (Figure 4).
Patient was recalled after two weeks and bilateral three unit fixed partial dentures was planned that involved the mandibular second premolars and second molars. Patient was recalled for follow up at periodic intervals of 3 and 6 months. (Figure 5).
DISCUSSION
An awareness of the anatomical variations and statistical data pertaining to the morphology of mandibular premolars is essential if the clinician is to achieve a high degree of success using a non surgical endodontic approach.
Factors that can contribute to differences observed in the various anatomic variations in second premolar teeth have been reviewed in detail by Cleghorn et al 8.In their radiographic survey, Serman and Hasselgren concluded that roots and root canals of mandibular premolar teeth were mostly situated buccally and lingually. The incidence of two roots in mesial and distal location is an uncommon appearance 9.
Taking into consideration that so many morphological variations exists in these teeth use of superior diagnostic aids and knowledge of anatomical variations can help the clinician to identify and treat multiple root canal systems in mandibular premolars successfully.
Good quality radiographs are of obvious value in determining both external and internal anatomy of teeth. The second radiograph should be taken at a horizontal angle of 20 degrees from the mesial or distal of the tooth to better visualise its bucco lingual anatomy. 10
Radiographs produce only a two dimensional image of a three dimensional object resulting in superimposition of images. Hence they are of limited value in cases with complex root canal anatomy. The clinician will be alerted to the presence of aberrant anatomy but would not be able to present variable morphological structure of root canals and their interrelations. The advent of 3D imaging has provided the endodontist with tools that were not available to the clinician before and facilitated interactive image manipulation and enhancement to visualize the area of interest.
Volumetric computerized tomography or cone beam tomography is a relatively new diagnostic imaging modality having been used in endodontic imaging. It offers high resolution images in a 3D format. However its high cost, accessibility to patient and extra radiation as compared to radiographs makes its routine used limited. Tuned aperture computed tomography a relatively new 3D imaging modality has also been introduced in endodontics and show great promise.Potential applications in endodontics include determination of configuration and length of root canal, presence of accessory canals etc.3D imaging will find more applications in endodontics in future as technology continues to advance. 11
References:
Bilateral Mandibular Second Premolar With Mesial and Distal Roots; An Uncommon Feature
Sardar Patel Post Graduate Institute of Dental And Medical Sciences, Rai Bareilly Road, Lucknow-226025
ABSTRACT
Mandibular premolar teeth show extreme variations in root canal morphology. Second premolars usually exhibit the basic one root and one canal anatomy. The occurrence of mesial and distal roots has not been commonly reported in literature. This article reports a case of successful nonsurgical endodontic management of bilateral mandibular second premolars with two separate roots with an uncommon mesial and distal morphological location confirmed with the help of spiral computed tomography and to review those factors which will assist the clinician in the detection and subsequent treatment of multiple canals in mandibular premolars.
INTRODUCTION
The main objective of endodontic therapy is thorough mechanical and chemical debridement of the entire root canal followed by a three dimensional obturation with an inert filling material and final restoration thereby providing a coronal seal 1.
Weine has cited the major causes of endodontic treatment failure are incorrect canal instrumentation, incomplete obturation and untreated major canals2.Failure to recognise the presence of an additional root and or root canal in any tooth may result in unsuccessful treatment and may be the origin of acute flare ups during and after treatment3.
Because of the variations in canal anatomy, the mandibular premolars as a group are the most difficult teeth to treat endodontically and hence they have a high flare up and failure rate 4.Washington study assessing the results of endodontic therapy had a failure rate of 11.45% in in Mandibular 1st premolars and 4.54%failure in mandibular 2nd premolars 5.A possible explanation may be the extreme variations in root canal morphology of mandibular premolar teeth compared with the standard description of one root, one canal found in text of dental anatomy 6. Another important point that should be emphasised is the anatomic position of mental foramen and neurovascular structures that pass through it in close proximity to the apices of mandibular premolars. There are reports of flare-ups in mandibular premolars with associated paraesthesia of the inferior alveolar and mental nerves because of missed root canals 7.
Therefore, awareness and understanding of the presence of unusual external and internal root canal morphology largely contributes to the successful outcome of the root canal treatment.
The purpose of this article is to report a case of successful nonsurgical endodontic management of bilateral mandibular second premolars with uncommon root morphology presenting with two separate roots located mesially and distally and to review those factors which will assist the clinician in the detection and subsequent treatment of multiple canals in mandibular premolars.
CASE REPORT
A twenty eight year old female patient of Indian descent was referred to the Post Graduate Department of Conservative Dentistry and Endodontics with chief complaint of intermittent pain over three months in relation to lower left and right mandibular premolar region. Patient also complained of episodes of sensitivity to hot and cold in the involved teeth. Medical history was non-contributory. Dental history revealed that she had undergone root canal treatment of maxillary left first premolar and bilateral extraction of mandibular first molars .
On clinical examination, patient’s oral hygiene was found to be moderate. Distal proximal caries was observed in both the mandibular first premolars . Deep distal proximal carious lesion was noted in the left and right mandibular second premolars and both teeth were tender on percussion. Vitality tests using thermal and electric pulp tests (Sybron Endo,USA) revealed a rapid lingering painful response. There was no evidence of swelling or sinus tract.
At first glance, the preoperative periapical radiographic examination showed presence of two roots bilaterally in mandibular second premolars (Figure1A,1B). A second radiograph with more mesial angulation was taken for a clear view to exclude the presence of third root. Two roots were found to be distinguished as mesial and distal.
Based on clinical and radiographic evidences a probable diagnosis of acute pulpitis with apical periodontitis was made.
 |
 |
|
Figure 1. Showing diagnostic radiograph of lower left (A) and right (B) mandibular premolars |
|
Access was gained to the pulp chamber after administration of local anaesthesia with2% lignocaine with adrenaline (Septodont, France) under rubber dam isolation. To gain sufficient access to the canals, the conventional access opening was modified into one that was wider mesio-distally. Orifice location was not easy as the coronal pulp chamber was usually long and the separation of roots was from the middle third of the root. The two canal orifices were located under magnification using surgical operating microscope (Zeiss,Germany) and patency was ascertained using a small size 10 K file. The working length radiograph was taken.(Figure 2A,2B).
 |
 |
|
Figure 2. Showing working length radiograph of lower left (A) and right (B) mandibular second premolars |
|
Gates Glidden drill (Dentsply, Maillifer, USA) with brushing motion in a crown down fashion was used to enlarge the orifice to achieve a straight line access to the apex. The canals were cleaned and shaped with Protaper files(Dentsply, Maillifer, USA) with sequentially irrigated using EDTA (Glyde File Prep. Dentsply, Maillifer, USA) and 3% sodium hypochlorite and dried with paper points.
Cotton was placed in the pulp chamber and cavit (3M ESPE) was used to close the access cavity. At the second appointment canals were rinsed with 3% sodium hypochlorite followed by a final rinse with saline, dried and obturated with F2 Protaper gutta perch points (Dentsply,Maillifer, USA) using zinc oxide eugenol and sealer (Septodont,France). The access cavity was filled with silver amalgam (DPI, India) (Figure 3A,3B).
 |
 |
| Figure 3. Radiograph showing obturated mandibular left (A) and right (B) second premolars | |
To confirm the complex root canal anatomy of the tooth spiral CT scan (Siemens,Germany) using dental software Dentascan was planned after obturation and informed consent of the patient was obtained (Figure 4).
Patient was recalled after two weeks and bilateral three unit fixed partial dentures was planned that involved the mandibular second premolars and second molars. Patient was recalled for follow up at periodic intervals of 3 and 6 months. (Figure 5).
 |
 |
| Figure. 4. Spiral CT showing obturated bilateral mandibular premolars with two roots |
Figure. 5. Panoramic view at 6 month recall. |
DISCUSSION
An awareness of the anatomical variations and statistical data pertaining to the morphology of mandibular premolars is essential if the clinician is to achieve a high degree of success using a non surgical endodontic approach.
Factors that can contribute to differences observed in the various anatomic variations in second premolar teeth have been reviewed in detail by Cleghorn et al 8.In their radiographic survey, Serman and Hasselgren concluded that roots and root canals of mandibular premolar teeth were mostly situated buccally and lingually. The incidence of two roots in mesial and distal location is an uncommon appearance 9.
Taking into consideration that so many morphological variations exists in these teeth use of superior diagnostic aids and knowledge of anatomical variations can help the clinician to identify and treat multiple root canal systems in mandibular premolars successfully.
Good quality radiographs are of obvious value in determining both external and internal anatomy of teeth. The second radiograph should be taken at a horizontal angle of 20 degrees from the mesial or distal of the tooth to better visualise its bucco lingual anatomy. 10
Radiographs produce only a two dimensional image of a three dimensional object resulting in superimposition of images. Hence they are of limited value in cases with complex root canal anatomy. The clinician will be alerted to the presence of aberrant anatomy but would not be able to present variable morphological structure of root canals and their interrelations. The advent of 3D imaging has provided the endodontist with tools that were not available to the clinician before and facilitated interactive image manipulation and enhancement to visualize the area of interest.
Volumetric computerized tomography or cone beam tomography is a relatively new diagnostic imaging modality having been used in endodontic imaging. It offers high resolution images in a 3D format. However its high cost, accessibility to patient and extra radiation as compared to radiographs makes its routine used limited. Tuned aperture computed tomography a relatively new 3D imaging modality has also been introduced in endodontics and show great promise.Potential applications in endodontics include determination of configuration and length of root canal, presence of accessory canals etc.3D imaging will find more applications in endodontics in future as technology continues to advance. 11
References:
- RödigT, Hülsmann M. Diagnosis and root canal treatment of a mandibular second premolar with three root canals. Int Endod J 2003;36:912–9.
- Weine Endodontic Therapy,5th Edition Boston,MA,USA,;Mosby.
- Cohen S, Burns R. Pathways of the pulp. 2001 8th ed. St Louis: Mosby, page 31-75.
- Slowey RR. Root canal anatomy:road map to successful endodontics. Dent Clin North Am 1979;23:555-73.
- Ingle JI, Bakland LK. Endodontics. 5th ed. New York, NY: Elsevier; 2003;page747–51.
- Wheeler’s Dental anatomy,Physiology, and Occlusion.8thEdition,Elsvier;2004.page 239-61.
- Glassman GD.Flare-up with associated paraesthesia of a mandibular second premolar with three roots. Oral Surg oral Med Oral Pathol 1987;64;110-3
- Cleghorn BM, Christie WH, Dong CC. The root and root canal morphology of the human mandibular first premolar: a literature review. J Endod 33:509 –516.
- Serman NJ, Hasselgren G. The radiographic incidence of multiple roots and canals in human mandibular premolars. Int Endod J 1992;25:234 –7.
- Walton RE.1973.Endodontic radiographic techniques. Dental Radiography and Photography.46,51-9.
- Nair MK, Nair UP. Digital and advanced imaging in endodontics; A review.2007; J Endond.Vol 53.No 1.page1-6.
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