Department of Conservative Dental Sciences, IBNSINA National College for Medical Studies, Jeddah, Saudi Arabia
Corresponding author details:
Dr. Prashanth, M.B BDS, MDS
Department of Conservative Dental Sciences IBNSINA National College for Medical Studies (Dentistry Program)
Al-Mahajar Street
Jeddah,Saudi Arabia
Copyright:
© 2019 Dr. Prashanth.M.B etal.
This is an open-access article distributed
under the terms of the Creative Commons
Attribution 4.0 international License, which
permits unrestricted use, distribution, and
reproduction in any medium, provided the
original author and source are credited.
Aim: This case report describes how to diagnose and to manage clinically in three rooted upper first premolar with the aid of CBCT and magnification (DOM).
Summary: According to the previous studies, the prevalence of morphological variations
in root canal system is known fact. Upper premolars highly vary in the morphology of the
root canal, but the incidence of three roots and canals are very rare. In this case, the report
discusses to diagnose and manage endodontically of an upper first premolar with three canals
with their three distinct roots, drawing particular attention to radiographic interpretation,
CBCT, Dental Operating Microscope, and access modification.
Anatomical variations; CBCT; Endodontic treatment; Magnification; Three rooted
maxillary first premolars
Incidence [1] of three canals in maxillary first premolars found to be 5-6% [2] and second
premolars to be 1%. According to the study done by Vertucci and Gegauff, 5% of 400 maxillary
first premolar had three canals; 0.5% showed three canals in a single root, 0.5% showed two
canals in one root and single canal in another root, 4% showed single canal in three distinct
roots. A study done by Carns and Skid more [2] showed 6 out of 100 maxillary first premolar
had three canals in three separate roots. To achieve successful [3] root canal treatment,
thorough knowledge of root canal morphology, high quality of preoperative radiograph [4],
tactile examination of pulpal floor and pulpal chamber and disinfection in entire root canal
system is required [5]. Major causes attributed to the failure of endodontic treatment are
missed canals, improper instrumentation, and Obturation [1]. Previous studies have been
reported on the various configuration of maxillary first and second premolars [6-9]. Because
of the similar morphology of maxillary premolars with three root canals to that of adjacent
molars, maxillary premolars are called as ‘’small molars’’ or ‘’ ridiculous’’ [10,11]. ‘’Sieraski’’
et al. [12] study found that radiographically whenever the mesiodistal width of [8] mid root
image is equal to or greater than mesiodistal widths of the crown, tooth most likely had three
roots [2]. Preoperative radiograph gives a two-dimensional view of the three-dimensional
object, but accurate interpretation can reveal fine morphology suggesting the existence of
extra roots or canals. Whenever there is sudden disappearance of radiolucency in the pulp
cavity will suggest extra canal [13]. Thus the proper interpretation of preoperative radiograph
[14-16] and use of Dental Operative Microscope (DOM) and Cone Beam Computer Tomogram
(CBCT) as an additional diagnostic tool to determine the anatomical variations [7,8] will lead
to great success.
A 41 year old male patient with non-contributory medical history was referred to the
department of Conservative dentistry for root canal treatment of maxillary right first
premolar [17]. A Chief complaint of the patient was a pain [8] in relation to the upper right
posterior region from the past eight weeks. Nature of the pain was dull and intermittent.
Intraoral clinical examination reveals deep caries with no evidence of swelling and sinus
tract. A Tooth was mild tender on vertical percussion. Pulp sensibility test with cold (Ethyl
chloride spray) and electric pulp tester (PARKELL INC, EDGEWOOD, NEW YORK) revealed no
response from the maxillary first premolar. The Pre-operative Periapical radiograph revealed
a large proximal caries involving the pulp and widening of periodontal ligament space with
no evidence of Periapical pathology was seen in relation to tooth 14 (Figure 1). Based on
clinical and radiographic interpretation, it was diagnosed as necrotic pulp with symptomatic
apical periodontitis [7]. Greater mesiodistal diameter in the middle third of the first premolar
externally and the sudden disappearance of radiolucency in the pulp cavity suggested extra
roots and canals [2]. Treatment plan of an involved tooth was decided to perform endodontic
treatment, prior to treatment, subjected to undergo Cone Beam Computed Tomography
(CBCT) to confirm root canal anatomy. The Procedure was [15] briefed to the patient and written consent was taken. The Patient was subjected to CBCT
(Kodak Dental Systems, Care stream Health, Rochester, NY, USA) and
confirmed three separate roots in first premolar (MB, DB&P) (Figure
2). The tooth was anesthetized with LOX 2% Adrenaline (1:200000).
Following isolation with a rubber dam, an endodontic access opening
was made under magnification of a dental operating microscope (G6,
Global Surgical Corp, 8.0X, St. Louis, MO, and U.S.A). Access cavity was
prepared using an Endo-Accessbur (DENTSPLY Maillefer, Switzerland)
and [1] modification in access cavity by giving a cut at a Bucco-proximal
angle from the beginning of buccal canals to the cavo surface angle
resulting in a ‘T’ shaped outline cavity. All the three, Mesiobuccal (MB), distobuccal (DB) and the palatal (P) canals were explored with DG-16
endodontic explorer (Figure 3) [4]. Working length was determined
using apex locators (Root ZX, J. Morita, and USA) and radiographically
confirmed (Figure 4). Canals ware [13] cleaned and shaped using
crown down technique with rotary instruments (ProTaper, DENTSPLY
Maillefer, Ballaigues, Switzerland), followed by disinfecting canals
with 5.25% sodium hypochlorite [7] irrigant solution. All the root
canals were enlarged to size F3 and final irrigation was done with 17%
EDTA solution. Master F3 cone was selected and check in master cone
radiograph was taken (Figure 5). Obturation was done with cone and
sealer (AH Plus, DENTSPLY, Ballaigues, Switzerland) and access cavity
was restored with MD-Temp (Temporary Restorative, META BIOMED,
Korea). Post-Obturation radiograph was taken (Figure 6). The Patient
recalled after one weak for permanent access cavity filling with
adhesive composite restoration (ClearlmajestyTM posterior, Kuraray
America, Inc. NY, USA). Follow up radiograph taken after three months
(Figure 7) and tooth 14 found to be asymptomatic.
Figure 1: Preoperative intraoral peri-apical radiograph
Figure 2: CBCT Images
Figure 3: Magnification of canal orifices from Dental
Operating Microscope (DOM, Global)
Figure 4: Working length radiograph
Figure 5: Check in master cone radiograph
Figure 6: Post Obturation radiograph
Figure 7: Follow up radiograph
In literature, possible anatomic variations in maxillary premolars
are well documented. For detection of additional root canals, the
prerequisite is high-quality preoperative radiographs and their careful
interpretation [14-16]. Walton’s study [1,17] advocated the use of
two diagnostic radiographs at different angulation. Abrupt loss of
radiolucency in pulp space or sudden narrowing in radiograph suggests
splitting of the canal into two separate canals or may merge before
exiting at apex [18]. If a canal orifice is situated eccentrically, at least one more canal is present and searched for in opposite direction. If the pulp
chamber does not appear to be aligned in its expected Bucco-palatal
relationship, a third canal can be suspected clinically. In addition, if it
appears to deviate from the normal configuration of the pulp chamber
and seems to be either too large in a mesiodistal plane or triangular
shape, an additional root canal may be suspected [19]. Variations in the
morphology of pulp cavity make the endodontic treatment uniquely
challenging. The proximity of the buccal orifices is close to each other
in three-rooted maxillary premolars are hard to locate. Balleri et al.
[20] suggested a modified access cavity outline, shaped by a cut at the
Bucco-proximal angle from the entrance of the buccal canals to the
cavosurface angle resulting in ‘T’ shaped access outline. Radiographic
image [6] produces two dimensional (2D) representation of three
dimensional (3D) objects. CBCT [6] in endodontics plays an important
role that demonstrates anatomic feature in 3D that panoramic and
cephalometric images can’t produce. Hence this case highlights the
utilization and importance of magnification (DOM) along with CBCT
to diagnose and manage [11] three-rooted maxillary first premolar
efficiently.
Thorough knowledge about root canal configuration and its
variations will aid in achieving successful root canal treatment.
Complex root canal anatomy demands modification in the access
cavity. When encountered with unusual anatomy, additional
Figure 6: Post Obturation radiograph
Figure 7: Follow up radiograph
diagnostic aid like magnification (DOM/LOOP) in endodontics and
CBCT utilization to locate all orifices and manage optimally.
Author acknowledge Dean Dr. Rashad Al Kashgari and Vice
Dean, and Dr. Othman Wali (Dentistry Program) for providing
facilities to carry out the study.
Copyright © 2020 Boffin Access Limited.