|Year : 2015 | Volume
| Issue : 2 | Page : 121-125
Endodontic management of radix paramolaris with pulp stone in a mandibular permanent first molar
Abhirup Goswami1, Swagat Panda2, Amitava Bora1, Gautam Kumar Kundu1, Utpal Kumar Das2
1 Department of Pedodontics and Preventive Dentistry, Guru Nanak Institute of Dental Sciences and Research, Kolkata, West Bengal, India
2 Department of Conservative Dentistry and Endodontics, Guru Nanak Institute of Dental Sciences and Research, Kolkata, West Bengal, India
|Date of Web Publication||20-Apr-2015|
No: 3, M. C. Lahiri Street, Chatra, (Serampore-4), Hooghly - 712 204, West Bengal
Variation of root canal anatomy is always a challenge for accurate diagnosis and subsequent successful endodontic therapy. A thorough knowledge of most common anatomic characteristics and their possible variations is essential for the clinician. The hard tissue repository of the human dental pulp takes on numerous configurations and shapes. These aberrations occur so often that they can be considered as normal anatomy. Radix paramolaris is one such aberration where an extra root is present on the mesiobuccal aspect of mandibular first molar. This article reports a case of successful endodontic management of a three rooted mandibular first molar with chronic irreversible pulpitis and emphasizes on the modifications in access and canal preparation, problems encountered during treatment, common iatrogenic errors during the endodontic intervention and factors, which affect the prognosis.
Keywords: Endodontic treatment, mandibular molar mesiobuccal root, pulp stone, radix paramolaris
|How to cite this article:|
Goswami A, Panda S, Bora A, Kundu GK, Das UK. Endodontic management of radix paramolaris with pulp stone in a mandibular permanent first molar. SRM J Res Dent Sci 2015;6:121-5
|How to cite this URL:|
Goswami A, Panda S, Bora A, Kundu GK, Das UK. Endodontic management of radix paramolaris with pulp stone in a mandibular permanent first molar. SRM J Res Dent Sci [serial online] 2015 [cited 2020 Aug 13];6:121-5. Available from: http://www.srmjrds.in/text.asp?2015/6/2/121/155474
| Introduction|| |
Molars are frequently affected by caries at an early age and may require successful endodontic treatment for their long-term retention in the oral cavity. The objective of endodontic therapy is complete removal of the pulp tissue from all the root canals, followed by chemo-mechanical cleaning and finally obturation of the canals with a suitable material.
Majority of the mandibular first molars are two rooted with two mesial and one distal canal. On rare occasions, a small shorter third root is found on the distolingual aspect of mandibular 1 st molars and is called "radix entomolaris" (RE), a very interesting example of anatomic variation. This additional third root was first mentioned in the literature by Carabelli  in 1844 and is described by various terms, such as "extra third root" or "distolingual root" or "extra distolingual root."  Radix paramolaris (RP) on the other hand is known as the "mesiobuccal root"  and was first described by Bolk  in 1915. In spite of high prevalence of RE in certain races, its incidence among the Indian population is found to be very low and is only 1.58%. 
An awareness and thorough knowledge of internal and external root canal morphology contribute to the successful root canal treatment. Hence, it is of utmost importance that the clinicians have to be familiar with this aberrant root anatomy. Failure to diagnose and treat these extra roots in molars may lead to endodontic treatment failure and even tooth loss at an early age resulting in the patient to suffer functionally, esthetically, and psychologically.
| Case report|| |
A 12-year-old female child reported to the outpatient dept. of Department of Pedodontics and Preventive Dentistry, Guru Nanak Institute of Dental Sciences and Research, Kolkata; with the chief complaint of pain in right lower back teeth region since 1-week. She visited a local dentist, from where she was referred to our department. The pain aggravated on taking cold and hot food items and upon mastication. Her medical history was noncontributory. Clinical examination revealed deep occlusal carious lesion in 46 and it was tender to both percussion and apical palpation. The periodontal health of 46 was within the normal limits. Thermal and electric pulp testings were done with molten Gutta-percha and Digitest II™ electric pulp tester (Parkell™, New York, USA), respectively, on 46, which did not evoke any responses. Intraoral periapical radiography of 46 was done with a Sopix 2™ RVG system (Sopro Imaging™, France), which revealed deep caries extending to the pulp space with diffused radio opacities throughout the pulp chamber indicating presence of pulp stones. There was slight widening of the periodontal ligament space around the mesial root. The canal outlines of the mesiobuccal and distobuccal roots were quite clear and traceable up to the apex.
Based on the clinical and radiographic examinations, a diagnosis of symptomatic irreversible pulpitis with acute apical periodontitis in 46 was made, and the patient was suggested to undergo root canal treatment.
Apart from this, close inspection of the radiograph also revealed the presence of an additional periodontal ligament space crossing over the mesial root leading to an impression of double periodontal ligament space on the mesial aspect. This led to the suspicion of an additional or extra root entity [Figure 1]. The treatment was carried out in association with the Department of Endodontics and Conservative Dentistry, Guru Nanak Institute of Dental Sciences and Research, Kolkata.
|Figure 1: Preoperative intraoral periapical radiography: Presence of an additional periodontal ligament space crossing over the mesial root|
Click here to view
Root canal treatment in 46 was initiated under rubber dam isolation, following Inferior alveolar nerve block with 2% lignocaine hydrochloride containing 1:80,000 adrenaline. Access preparation was done with an endo access bur no. 1 [Figure 2]. A proper bur drop could be felt in the pulp chamber since it was not completely obliterated with pulp stone. The calcified mass was clinically visible as an irregular translucent mass attached to the walls and the floor of the pulp chamber. After carefully extending the access cavity, an ultrasonic nonactive tip with active lateral part Start-X™ #1 (Dentsply Maillefer) [Figure 3] was introduced with a Piezo ultrasonic generator (EMS MINIPIEZON™) for further refinement of access cavity walls and displacement of the calcified mass from the walls. An ultrasonic tapered and active tip Start-X™ #3 (Dentsply Maillefer) [Figure 4] was introduced to remove the calcific obstruction from the floor. Then the entire mass was dislodged from the walls of the pulp chamber and its underlying attachment [Figure 5].
After the primary access opening, one distal and two mesial canal orifices were located using an endodontic explorer (DG-16™ Endodontic Explorer, Ash Instruments, Dentsply, UK). The root canals were explored with a K-file ISO 15 (Dentsply Maillefer, Switzerland). On visual inspection, a dark line was observed between the distal canal orifice and the mesio buccal corner of the pulp chamber floor. Then the access cavity preparation was modified and extended towards the mesiobuccal corner, giving the earlier conventional triangular access cavity a buccally extended shape. At this mesiobuccal corner, the overlying dentin was removed with a Start-X™ #3 [Figure 4] active tip, and a small reddish spot was noted buccally between the distal and the mesial orifices on the pulp chamber floor. Bubbles were noted when a drop of sodium hypochlorite was placed on the hemorrhagic spot (champagne bubble test) and the opening was confirmed as a buccal canal orifice. Exploration of the pulp chamber floor now revealed five canal orifices (3 mesial and 2 distal). The floor was further refined using a Start-X™ #5 tip [Figure 6]. The pulpal tissue remnants were extirpated from the canals using K file no. 10 and no. 15 (Dentsply Maillefer, Switzerland). Coronal flaring was accomplished with Gates Glidden drills (Mani, India) [Figure 7]. Working length was determined using an apex locator (Root ZX, Morita, Tokyo, Japan). The root canals were cleaned and shaped by rotary nickel-titanium ProTaper™ files (Dentsply Maillefer) [Figure 8] in a crown down manner using Glyde™ (Dentsply Maillefer) [Figure 6] as a lubricant. The canals were sequentially irrigated using 5.25% sodium hypochlorite, 17% ethylenediaminetetraacetic acid (EDTA), normal saline, and 2% chlorhexidine solution. The canals were thoroughly dried, and all the root canals were coated with AH plus™ resin based sealer (Dentsply Maillefer) [Figure 7]. Obturation was carried out using ProTaper Gutta-percha points (Dentsply Maillefer) [Figure 7]. The access cavity was restored with posterior composite resin. Postobturation radiograph was taken, which showed well obturated root canals [Figure 9]. The patient was asymptomatic during the follow-ups of 6 months [Figure 10].
| Discussion|| |
As per Bernick and Nedelman, it appears that pulp stone prevalence can be close to 100%, particularly if associated with carious or restored first molars.  Prevalence of pulp stones in maxillary first molars that were restored and/or carious had significantly higher occurrences (41.7%) as opposed to those were unrestored and intact (28.8%).  Within the narrow canals, ultrasonics should ideally be coupled with the dissolving action of sodium hypochlorite on the collagen-based tissues in the canal to produce a synergistic effect.  In accordance with the case presented, it was treated using special ultrasonic tips Start-X™ (Dentsply Maillefer) with a combination of 5.2% sodium hypochlorite and 17% EDTA solution as an irrigant.
Reports have been presented by Pomeranz et al.,  and Goel et al.  on the incidence of RP in mandibular molars, with an occurrence ranging from 1% to 15% in vivo. However, in vitro studies have not reported such a high prevalence of three mesial canals, with most studies showing an incidence of either 0% or 1%. ,
Pomeranz et al.  classified three separate morphological possibilities in the mesial root:
- Fin - when an instrument could pass freely between the mesiobuccal or mesiolingual canal and the middle mesial canal;
- confluent - when the prepared canal originated as a separate orifice but apically joined the mesiobuccal or mesiolingual canal; and
- independent - when the prepared canal originated as a separate orifice and terminated as a separate foramen (like in the reported case here).
The external morphology and dimensions of this buccal supernumerary root was described by Carlsen and Alexandersen.  According to them, the dimensions of the RP can vary from a "mature" root with a root canal to a short conical extension. This additional root can be separate or nonseparate. They described two different types: Types A and B. Type A refers to an RP in which the cervical part is located on the mesial root complex; type B refers to an RP in which the cervical part is located centrally, between the mesial and distal root complexes. Here the case was a type A kind of RP.
The presence of an RE or an RP has great clinical implications in endodontic treatment. An accurate diagnosis of these supernumerary roots can avoid complications of a "missed canal" during root canal treatment. Because the (separate) RP is mostly situated in the same buccolingual plane with the mesiolingual root, a superimposition of both roots can appear on the preoperative radiograph, resulting in an inaccurate diagnosis. A thorough inspection of the preoperative radiograph and interpretation of particular marks or characteristics, such as an unclear view or outline of the mesial root contour or the root canal, can indicate the presence of a "hidden" RP. To reveal the RP, a second radiograph should be taken from a more mesial or distal angle (30°). Three-dimensional imaging systems, which make possible observations from arbitrary viewpoints, are replacing two-dimensional methods for morphological studies of the pulp space. Nance et al. reported that tuned-aperture computed tomography (CT) imaging enabled a statistically significant increase in root canal detection as compared with conventional two-dimensional radiography.  Cone beam and spiral CTs are the two most recent advances in CT technology where a three-dimensional data set is acquired and then reconstructed into images representing a transverse section of the object.  In addition, there are multiple concepts, armamentaria and instruments that are useful to find these aberrant canals. These include the use of micro-openers, properly designed access cavity, bubble test, champagne test, transillumination, use of piezoelectric ultrasonics, looking for the rules of symmetry, red line test, white line test and perio-probing.
Apart from a radiographical diagnosis, clinical inspection of the tooth crown and analysis of the cervical morphology of the roots by means of periodontal probing can facilitate identification of an additional root. An extra cusp (tuberculum paramolare) in combination with a cervical prominence or convexity can indicate the presence of an additional root.
A dark line on the pulp chamber floor can indicate the precise location of the RP canal orifice [Figure 11]. The mesial and buccal pulp chamber wall can be explored with an angled probe to reveal overlying dentin or pulp roof remnants masking the root canal entrance. The calcification, which is often situated above the orifice of the RP, has to be removed for a better view and access. To avoid perforation or stripping in the coronal third of a severe curved root, care should be taken not to remove an excessive amount of dentin on the buccal side of the cavity and orifice of the RP. ,
| Conclusion|| |
Teeth are never alike. A number of variations occur which pose a challenge to a clinician. This particular variation (RP) may be a challenge for those who do not have proper diagnostic aids and lack in proper knowledge of root canal anatomy. The initial diagnosis of a RP before root canal treatment is of utmost importance to facilitate the endodontic procedure and to avoid "missed" canals. It has been speculated that recent studies using advanced techniques showed a higher prevalence compared to previous conventional two-dimensional radiological studies. The reason could be attributed to the use of three-dimensional image analysis (cone-beam computed tomography/spiral CT), which provides far more accurate determination of these aberrant root morphologies. Correct diagnosis should be made with at least two preoperative radiographs taken at two different angles before starting the treatment. A thorough knowledge of root canal anatomy and awareness of the variations make the treatment more successful, and if one exhibits proper skill, these cases can be handled with ease (2002 words).
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11]