Evaluation of Root Canal Configuration of Maxillary Molars in a Brazilian Population Using Cone-beam Computed Tomographic Imaging: An In Vivo Study

Introduction

The aim of this study was to analyze and characterize root canal morphology of maxillary molars of the Brazilian population using cone-beam computed tomographic (CBCT) imaging.

Methods

Patients referred for a CBCT radiographic examination for accurate diagnosis and treatment planning were enrolled in the study. A total of 620 healthy, untreated, fully developed maxillary first and second molars were included (314 first molars and 306 second molars). The following observations were recorded: (1) number of roots and their morphology, (2) number of canals per root, (3) fused roots, and (4) primary variations in the morphology of the root canal systems.

Results

First and second molars showed a higher prevalence of 3 separate roots, mesiobuccal, distobuccal, and palatal, with 1 canal in each root (52.87% and 45.09%, respectively). Two canals in the mesiobuccal roots represented 42.63% of teeth, whereas mesiobuccal roots of second molars presented 2 canals in 34.32%. The most common anatomic variation in the maxillary first molar was related to the root canal configuration of the mesiobuccal root, whereas the root canal system of the maxillary second molar teeth showed more anatomic variables.

Conclusions

Mesiobuccal roots of maxillary molar teeth had more variation in their canal system than the distobuccal or palatal roots. The root canal configuration of the maxillary second molars was more variable than the first molars in a Brazilian population. CBCT imaging is a clinically useful tool for endodontic diagnosis and treatment planning.     

Three Root Canals in the Mesiobuccal Root of Maxillary Molars: Case Reports and Literature Review

Introduction

The knowledge of root canal anatomy is essential to ensure a successful outcome of surgical and nonsurgical root canal treatment. The aims of this article were to present 2 cases of maxillary molars with 3 mesiobuccal root canals and to review the available literature on this anatomic variation.

Methods

The first case described a nonsurgical root canal treatment of tooth #16 in a 29-year-old man with the aid of a dental operating microscope. In the second case, an extracted maxillary right first molar was scanned by a micro–computed tomographic system and reconstructed 3-dimensionally using modeling software.

Results

In both cases, the mesiobuccal root had 3 canals (type 3-2 in case I and type 3-3 in case II), whereas the distobuccal and palatal roots had a single canal. The literature review showed that the overall incidence of 3-canaled mesiobuccal roots in maxillary molars ranged from 1.3%–2.4% and that the most common root canal configuration was type 3-2.

Conclusions

Clinicians should always anticipate the presence of extra canals in maxillary molars and use all the available tools to locate and treat these.     

Clinically Relevant Dimensions of 3-rooted Maxillary Premolars Obtained Via High-resolution Computed Tomography

Introduction

This study aimed to characterize the dimensions of a selection of 3-rooted maxillary premolars through high-resolution computed tomographic analysis considering measures of clinical interest for root canal treatment, such as root wall thickness, canal diameters, and distances between 2 canals in fused roots and between the root apex and foramen.

Methods

Fifteen 3-rooted human maxillary premolars extracted for therapeutic reasons were individually scanned using a high-resolution desktop high-resolution computed tomographic system. Starting from the apical foramen, the selected cross-sectional images corresponding to each millimeter of the roots were evaluated. Measures of clinical interest were determined using Image J software (version 1.41; National Institutes of Health, Bethesda, MD).

Results

Root wall thickness as thin as 0.4 and 0.6 mm was detected in the apical portion of buccal and palatal roots, respectively. In the cervical portion, buccal roots had narrower root walls (0.817–1.670 mm) compared with palatal roots (1.361–2.720 mm). In all thirds, the palatal canal was wider compared with the mesiobuccal and distobuccal canals. In the buccopalatal direction, all roots had thicker root walls toward the furcation, whereas in the mesiodistal direction the mesiobuccal and distobuccal roots had the thinnest walls along their distal and mesial aspects, respectively. Both buccal canals revealed dentin apposition 2 mm from the canal orifice, resulting in cervical constriction. Generally, the distance between the root apex and the foramen was greater in distobuccal roots in comparison with the others with a tendency for foramina to be eccentric.

Conclusions

Three-rooted premolars are a clinical challenge not just because of their low frequency and difficulties regarding diagnosis and root canals access but also because of their fragile roots. These phenomena are critical in terms of the amount of dentin removed during the preparation of root canals and during post space preparation.     

A study of the distobuccal root canal orifice of the maxillary second molars in Chinese individuals evaluated by cone-beam computed tomography

As is commonly understood, the root canal morphology of the maxillary molars is usually complex and variable. It is sometimes difficult to detect the distobuccal root canal orifice of a maxillary second molar with root canal treatment. No literature related to the distobuccal root canals of the maxillary second molars has been published.

Objective

To investigate the position of the distobuccal root canal orifice of the maxillary second molars in a Chinese population using cone-beam computed tomography (CBCT).

Material and methods

In total, 816 maxillary second molars from 408 patients were selected from a Chinese population and scanned using CBCT. The following information was recorded: (1) the number of root canals per tooth, (2) the distance between the mesiobuccal and distobuccal root canal orifice (DM), (3) the distance between the palatal and distobuccal root canal orifice (DP), (4) the angle formed by the mesiobuccal, distobuccal and palatal root canal orifices (∠ PDM). DM, DP and ∠ PDM of the teeth with three or four root canals were analyzed and evaluated.

Results

In total, 763 (93.51%) of 816 maxillary second molars had three or four root canals. The distance between the mesiobuccal and distobuccal orifice was 0.7 to 4.8 mm. 621 (81.39%) of 763 teeth were distributed within 1.5-3.0 mm. The distance between the palatal and distobuccal orifice ranged from 0.8 mm to 6.7 mm; 585 (76.67%) and were distributed within 3.0-5.0 mm. The angle (∠ PDM) ranged from 69. 4º to 174.7º in 708 samples (92.80%), the angle ranged from 90º to 140º.

Conclusions

The position of the distobuccal root canal orifice of the maxillary second molars with 3 or 4 root canals in a Chinese population was complex and variable. Clinicians should have a thorough knowledge of the anatomy of the maxillary second molars.     

Morphologic Micro–Computed Tomography Analysis of Mandibular Premolars with Three Root Canals

Introduction

This study aimed to describe the anatomy of mandibular premolars with type IX canal configuration by using micro–computed tomography.

Methods

Mandibular premolars with radicular grooves (n = 105) were scanned, and 16 teeth with type IX configuration were selected. Number and location of canals, distances between anatomic landmarks, occurrence of apical delta, root canal fusion, and furcation canals, as well as 2-dimensional (area, perimeter, roundness, major and minor diameters) and 3-dimensional (volume, surface area, and structure model index) analysis were performed. Data were statistically compared by using analysis of variance and Kruskal-Wallis tests (α = 0.05).

Results

Overall, specimens had 1 root with a main canal that divided into mesiobuccal, distobuccal, and lingual canals at the furcation level. Mean length of the teeth was 22.9 ± 2.06 mm, and the configuration of the pulp chamber was mostly triangle-shaped. Mean distances from the furcation to the apex and cementoenamel junction were 9.14 ± 2.07 and 5.59 ± 2.19 mm, respectively. Apical delta, root canal fusion, and furcation canals were present in 4, 5, and 10 specimens, respectively. No statistical differences were found in the 2-dimensional and 3-dimensional analyses between root canals (P > .05).

Conclusions

Type IX configuration of the root canal system was found in 16 of 105 mandibular premolars with radicular grooves. Most of the specimens had a triangle-shaped pulp chamber. Within this anatomic configuration, complexities of the root canal systems such as the presence of furcation canals, fusion of canals, oval-shaped canals in the apical third, small orifices at the pulp chamber level, and apical delta were also observed.     

Evaluation of Root and Canal Morphology of Maxillary Permanent First Molars in a North American Population by Cone-beam Computed Tomography

Introduction

The purpose of this study was to evaluate the number of roots and canal morphology of maxillary permanent first molars in a North American population.

Methods

Three hundred seventeen cases with bilateral maxillary first molars were included. All images from cone-beam computed tomography were carefully reviewed by 2 endodontists. Frequency of number of roots, presence of an additional mesiobuccal canal (MB2), and Vertucci canal type for each root were tabulated. Age, gender, and ethnicity differences were calculated with the χ² test. The intra-rater reliability was assessed by using the Cohen kappa statistic.

Results

The fused root rate was 0.9%. The occurrence of 3-rooted maxillary first molars differed between left and right sides (P = .03). MB2 occurrence only showed statistically significant differences among age groups (P = .005). In the mesiobuccal roots, the most common Vertucci classifications of canal types were type IV (2-2, 41.9%), type I (1, 28.3%), and type II (2-1, 26.3%). There was a statistically significant difference in Vertucci classification of canal type among 5 ethnic groups (African American, Asian, Hispanic, Other, and Non-Hispanic white, P < .001).

Conclusions

Cone-beam computed tomography facilitates the identification of root and canal configuration. The information gained about the tooth anatomy and canal morphology before treatment could potentially facilitate root canal therapy.     

A Rare Root Canal Configuration of Bilateral Maxillary First Molar with 7 Root Canals Diagnosed Using Cone-beam Computed Tomographic Scanning: A Case Report

Introduction

The complexity of the root canal system of maxillary molars presents a constant challenge in the diagnosis and treatment of these teeth. This case report describes the importance of a surgical operating microscope and cone-beam computed tomographic (CBCT) imaging.

Methods

Root canal treatment of a left maxillary first molar with 3 roots and 7 canals was successfully performed. Seven canals were identified with the help of a surgical operating microscope and CBCT imaging. CBCT images also confirmed the 3 roots and 7 canals in the right maxillary first molar.

Results

CBCT images confirmed a type IV canal pattern in the distal and palatal root, whereas the mesial root had a type VIII canal pattern.

Conclusions

The use of a surgical operating microscope and CBCT imaging helps the clinician to diagnose unusual anatomy of a tooth and facilitate successful endodontic treatment.     

Morphology of Mandibular First Molars Analyzed by Cone-beam Computed Tomography in a Korean Population: Variations in the Number of Roots and Canals

Introduction

The aim of this study was to determine the root and canal morphology of the mandibular first molars in a Korean population of Mongolian origin by retrospective analysis of a large number of cone-beam computed tomography (CBCT) images.

Methods

A total of 976 subjects with bilateral mandibular first molars were examined by using in vivo CBCT methods. The number and configuration of roots, the number of root canals, and the canal configuration based on Vertucci's classification were determined.

Results

Overall, 25.82% of examined molars had 3 roots, 73.51% had 2 roots, and 0.67% had 1 root. The incidence of fourth canal was 50.36%. A right-sided predominance was noted for extra distal roots (P < .001), whereas a left-sided predominance was observed for extra distal canals (P < .001). No significant sex-related differences were shown for their prevalence. The bilateral prevalence rate was 69.13% for extra distal roots and 78.08% for extra distolingual (DL) canals. In the mesial roots, type IV canal was the most frequent (76.86% for 2-rooted molars and 72.96% for 3-rooted molars). In the distal roots, type l was the most common (66.62% for 2-rooted molars and 99.40%–100% for 3-rooted molars). The incidence of 2 canals in distobuccal roots, first reported in this study, was 0.15%.

Conclusions

Among mandibular first molars, there is a high prevalence of a separate DL root and/or a separate DL canal, and such molars commonly have 4 canals in the Korean population. CBCT is a useful tool for determining root and canal morphology.     

Endodontic management of a maxillary first molar with eight root canal systems evaluated using cone-beam computed tomography scanning: a case report

Introduction

Root canal treatment of maxillary molars presenting with complex root canal configurations can be diagnostically and technically challenging.

Methods

Nonsurgical endodontic therapy of a left maxillary first molar with three roots and eight root canals was successfully performed. This unusual morphology was diagnosed using a dental operating microscope (DOM) and confirmed with the help of cone-beam computed tomography (CBCT) images.

Results

CBCT axial images showed that both the mesiobuccal and distobuccal root contained a Sert and Bayirli type XV canal, whereas the palatal root showed a Vertucci type II canal configuration.

Conclusions

The use of a DOM and CBCT imaging in endodontically challenging cases can facilitate a better understanding of the complex root canal anatomy, which ultimately enables the clinician to explore the root canal system and clean, shape, and obturate it more efficiently.     

The root and root canal anatomy of maxillary molars in a Chinese population

Abstract The purpose of this investigation was to study the prevalence of fused roots, C-shaped roots, C-shaped root canal orifices and C-shaped root canals in the maxillary molars of a Chinese population. A total of 305 first molars and 309 second molars were collected in Taiwan. The teeth were demineralized and placed in methyl salicylate to make them transparent. Root fusion was examined and the pulp chamber floor was checked for C-shaped orifices. Chinese ink was then injected into the root canal system to demonstrate possible C-shaped canals. The maxillary first molars had the palatal root fused with the mesiobuccal root in 0.3% of the cases, and with the distobuccal root in 2.0%. Teeth with C-shaped roots existed in only 0.3% of maxillary first molars, while 6.2% of the maxillary first molars and 40.1% of the maxillary second molars had fused roots. The maxillary second molars had the palatal root fused with the mesiobuccal root in 18.1% and with the distobuccal root in 2.6%; the palatal root was fused with the mesiobuccal and distobuccal root in 8.1% of the material. The maxillary second molars had a C-shaped root in 4.5% and C-shaped root canal orifices with C-shaped root canals in 4.9% of the cases. Fused roots or incompletely separated roots are common in the maxillary second molars amongst Chinese people, while C-shaped roots and root canals in maxillary molars are not frequently seen.     

Root and canal morphology of maxillary first and second permanent molar teeth in a Ugandan population

AIM: To investigate the root and canal morphology of permanent maxillary molar teeth from a Ugandan population. METHODOLOGY: Maxillary first (n = 221) and second molar (n = 221) teeth were collected from patients attending dental clinics in Kampala. Teeth were prepared using a clearing technique: the pulp chambers were accessed and the teeth placed consecutively into 5% sodium hypochlorite, 10% nitric acid, then methyl salicylate. Indian ink was injected into the pulp chambers to demonstrate the canal system. RESULTS: In the first molars, 95.9% of the teeth had separate roots. The mesiobuccal root was fused with the palatal root in 3% of specimens and with the distobuccal root in 0.5% of teeth. In the second molars, 86% of the teeth had separate roots. The mesiobuccal root was fused with the palatal root in 6.3% of specimens and with the distobuccal root in 6.8% of teeth. Apical deltas were more frequent in the mesiobuccal root when compared with distobuccal and palatal roots of both the first and second molars. A type I canal configuration (>75%) was the most frequent in all the roots of both the first and second molars. Canal intercommunications and lateral canals were more frequent in the mesiobuccal root when compared with other roots. CONCLUSIONS: The mesiobuccal root tended to have more variations in the canal system followed by the distobuccal root, whereas the palatal root had the least. The findings in root and canal morphology of this Ugandan population were different from previous studies, which may partly be attributed to racial differences.     

Use of Cone-beam Computed Tomography to Evaluate Root Canal Morphology and Locate Root Canal Orifices of Maxillary Second Premolars in a Chinese Subpopulation

Introduction

The aim of this study was to investigate root canal morphology and locate root canal orifices of maxillary second premolars in a Chinese subpopulation using cone-beam computed tomographic imaging.

Methods

A total of 392 cone-beam computed tomographic images of maxillary second premolars were obtained from 238 patients who required a preoperative assessment for implant surgery or orthodontic treatment. The number of roots and root canals and root canal configuration were investigated and categorized using Vertucci's criteria. The distance between the root canal orifice and the anatomic apex and the distance between root canal orifices in those teeth with 2 root canals were measured and evaluated. The Fisher exact test was used to analyze the correlation between the number of roots and sex.

Results

Among the 392 teeth, 86.5% (n = 339) had 1 root; 45.4% (n = 178) of the teeth had 1 root canal, and 54.3% (n = 213) had 2 root canals that ranged from type II–type V. The majority of teeth with 2 root canals showed a type IV canal configuration (n = 79, 20.2%) followed by type II (n = 64, 16.3%), type III (n = 45, 11.4%), and type V (n = 25, 6.4%). Only 1 tooth had 3 root canals. No significant difference was found between the number of roots and sex (P > .05). Among the 213 teeth with 2 root canals, the most frequent distribution of the distance between the root canal orifice and the anatomic apex was 5–10 mm (n = 157). The distance between the 2 orifices of 189 teeth was 1–4 mm.

Conclusions

The frequency of teeth with 2 root canals was high in maxillary second premolars. The internal morphology of teeth with 2 root canals was variable. This study provided useful information about the root canal morphology of maxillary second premolars in a Chinese subpopulation.     

Root Canal Morphology of South Asian Indian Mandibular Premolar Teeth

Introduction

The purpose of this study was to study the root canal morphology of South Asian Indian mandibular premolars using a tooth clearing technique.

Methods

Two hundred mandibular premolar teeth were collected from different dental schools and clinics in India. After pulp tissue removal and root canal staining with Indian ink, the specimens were decalcified with 5% nitric acid, dehydrated in ethyl alcohol, and subsequently cleared in methyl salicylate.

Results

Of the 200 mandibular premolars, 100 were first premolars and 100 were second premolars. Of the first premolars, 94% had a single root, whereas 6% were 2 rooted. Seventy-six percent had a single canal, 22% had 2 canals, and 2% had 3 canals. Eighty-two percent had a single apical foramen, 16% had 2 foramens, and 2% teeth had 3 apical foramens. Eighty percent of teeth had type I, 6% had type II, 10% had type IV, 2% had type V, and 2% teeth had type IX root canal anatomy. Of the 100 second premolars, 92% had a single root, whereas 8% teeth were 2 rooted and fused. Fifty-eight percent of teeth had a single canal, and 42% had two canals. Eighty-eight percent had a single apical foramen, and 12% had 2 foramens. Sixty-six percent had type I, 30% had type II, and 4% had type V root canal anatomy.

Conclusions

A high prevalence of 2 canals was noted in the first and second premolars. Also, 20% of first premolars and 34% of second premolars had a root canal anatomy other than type I.     

Root canal morphology of permanent three-rooted mandibular first molars: Part III--An odontometric analysis

Introduction

The purpose of this study was to quantitatively analyze the root canal morphology of three-rooted mandibular first molars by micro-computed tomography (micro-CT) scans.

Methods

Twenty three-rooted mandibular first molars were scanned by micro-CT scans. The teeth were reconstructed three-dimensionally by software Mimics 10.01 (Materialise, Leuven, Belgium). The levels of the root apexes and furcations; the diameters; wall thicknesses; and tapers of the mesiobuccal (MB), mesiodistal (ML), distobuccal (DB) and distolingual (DL) canals were determined. The buccolingual/mesiodiatal (BL/MD) diameter ratios (ΔC) and the prevalence of long oval canals (ΔC > 2) at different levels were calculated.

Results

The level of distal furcations was significantly (P < .01) lower than that of MD furcations with an average of 1.09 mm. The buccal and lingual walls were significantly (P < .05) thicker than the mesial and distal for the MB, ML, and DB canals. Among four canals, the DL canal had the smallest mean value of ΔC at each level. The average BL taper was greater than the MD for each canal except the middle portion of the DL canal.

Conclusion

The vertical length, width, BL/MD diameter ratio, wall thickness, and BL taper of the DB canals are on average greater than the DL canals. The MB, ML, and DB canals are more oval, whereas the DL canals are relatively rounder. The geometric data of root canals are useful for endodontic treatment on three-rooted mandibular first molars.     

A Cone-beam Computed Tomographic Study of Root and Canal Morphology of Maxillary First and Second Permanent Molars in a Thai Population

Introduction

Understanding tooth anatomy is crucial for effective endodontic treatment. This study investigated the roots and root canal morphology of maxillary first and second permanent molars in a Thai population using cone-beam computed tomographic (CBCT) imaging.

Correlation of Root Dentin Thickness and Length of Roots in Mesial Roots of Mandibular Molars

Introduction

The purpose of this study was to analyze the relation of tooth length and distal wall thickness of mesial roots in mandibular molars at different locations (ie, 2 mm below the furcation and at the junction between the middle and apical third).

Methods

Forty-five mandibular first molars were taken, and the length of each tooth was measured. Then, specimens were divided into three groups according to their length: group I–long (24.2 mm ± 1.8), group II–medium (21 mm ± 1.5) and group III–short (16.8 mm ± 1.8). mesial root of each marked at two levels - at 2 mm below the furcation as well as at junction of apical and middle third of roots. The minimum thickness of the distal root dentine associated with the buccal and lingual canals of the mesial roots was measured, The distance between the buccal and lingual canals and the depth of concavity in the distal surface of the mesial roots were also measured.

Results

Statistical analysis was performed by using analysis of variance and the Student-Newman-Keuls test. The minimum thickness of the distal wall of the mesiobuccal canal was significantly different (P < .001) between groups 1 (long) and 3 (short).

Conclusions

Distal wall thickness of the mesiobuccal root and distal concavity of the mesial root of mandibular first molars were found to be thinner in longer teeth compared with shorter teeth.     

Apical Root Canal Transportation and Remaining Dentin Thickness Associated with ProTaper Universal with and without PathFile

Introduction

This study aimed to compare, using digital subtraction radiography, apical transportation in mesiobuccal root canals of extracted human maxillary molars instrumented with ProTaper Universal F3 and F4 files (Dentsply Maillefer, Ballaigues, Switzerland) with and without the prior creation of glide paths using the PathFile system and to compare, using cone-beam computed tomographic imaging, remaining dentin thickness (RDT) after complete preparation.

Methods

Forty mesiobuccal roots with curvatures of 20°–35° were used. In group A, glide paths were created with PathFile #1, #2, and #3 to the working length; in group B, no glide paths were used. All canals were instrumented up to F4 to the working length. Digital subtraction radiographic images were obtained in buccolingual and mesiodistal directions. Apical transportation associated with F3 or F4 was calculated based on the difference between the tip of the first and the last instrument analyzed in each group. RDT was calculated based on cone-beam computed tomographic images.

Results

Apical transportation was higher after F4 regardless of the use of the PathFile system. No statistically significant differences between groups A and B were observed in apical transportation after instrumentation with F3 or F4 (P > .05). Group A showed greater RDT values at 2 (buccal and mesial walls, P < .05) and 3 mm (buccal and distal walls, P < .05) from the apex but not at 1 mm.

Conclusions

The use of the PathFile system before root canal preparation with ProTaper Universal F3 and F4 did not influence apical transportation but was associated with greater RDTs at 2 and 3 mm from the apex.     

The Validity of Cone-beam Computed Tomography in Measuring Root Canal Length Using a Gold Standard

Introduction

The distance between a coronal reference point and the major apical foramen is important for working length determination. The aim of this in vitro study was to determine the accuracy of root canal length measurements performed with cone-beam computed tomographic (CBCT) scans using a gold standard.

Methods

A total of 162 teeth (198 root canals) in 16 dry human dentulous mandibles were scanned using a 3DX-Accuitomo CBCT scanner (Morita 3DX; J Morita Mfg Corp, Kyoto, Japan). The root canal length was measured with CBCT data. All teeth were extracted atraumatically and endodontically accessed; the root canal length was measured blindly using a #10 K-file (Dentsply Maillefer, Ballaigues, Switzerland) and served as the gold standard.

Results

The mean absolute difference of the CBCT-based root canal length from the gold standard was 0.46 mm (95% confidence interval, 0.41–0.50 mm). Only in 9 of 198 (4.5%) roots did the difference between the CBCT-based root canal length and the gold standard exceed 1 mm.

Conclusions

CBCT-based root canal length measurements are accurate and reliable when compared with a gold standard.     

Cone-beam Computed Tomographic Scans in Comparison with Periapical Radiographs for Root Canal Length Measurement: An In Situ Study

Introduction

The primary aim of this study was to compare the precision of root canal length determination on cone-beam computed tomographic (CBCT) scans and periapical radiographs (PAs) with the actual root canal length. The secondary aim was to examine the influence of tooth type on root canal length measurements as assessed on CBCT scans and PAs.

Methods

In total, 40 root canals of 33 teeth (molars, premolars, canines, and incisors) out of 5 dentate maxillas of human cadavers were included. Root canal length measurement was performed by a consensus panel (2 examiners) on CBCT scans (3D Accuitomo 170; J Morita, Kyoto, Japan) and digital PAs. After straight-line access opening, a #15 file was fixated in every root canal at the length measured on CBCT scans. All teeth were extracted, and the root canal containing the file was uncovered. Measurements made on images taken with a digital camera (AxioCam; Carl Zeiss, Sliedrecht, The Netherlands) linked to a stereozoom microscope (Stemi SV6, Carl Zeiss) were used as the actual root canal length.

Results

When all roots were examined together, it was not clear which method is better for all types of teeth. For root canals of anterior teeth, there was no significant difference between the 2 methods. For root canals of posterior teeth, CBCT images gave results significantly closer to the actual root canal length in comparison with PAs (t value = −1.96; critical value is 1.74 with a significance level of 0.05).

Conclusions

Root canal length measurements of posterior maxillary teeth were more accurate when assessed by CBCT images than PAs.     

Infection in a Complex Network of Apical Ramifications as the Cause of Persistent Apical Periodontitis: A Case Report

Introduction

This article reports a case of persistent apical periodontitis lesion in a mesiobuccal root of a maxillary molar subjected to single-visit endodontic treatment.

Methods

The treatment protocol followed endodontic standards including using nickel-titanium instruments with working length ending 0.5-mm short of the apex, establishment and maintenance of apical foramen patency, irrigation with 5% NaOCl, smear layer removal, a final rinse with and ultrasonic agitation of chlorhexidine, and filling by the vertical compaction technique. Even so, the lesion in the mesiobuccal root became larger in size after follow-up examination at 1 year 6 months, and periradicular surgery was performed. Radiographic control after 11 months showed that periradicular healing was almost complete. The root apex and the lesion were analyzed histologically and histobacteriologically.

Results

The lesion was diagnosed as a “pocket cyst,” and no bacteria were noted extraradicularly. The cause of continued disease was a heavy bacterial biofilm infection located in an intricate network of apical ramifications. Bacteria were also observed on the walls of one of the mesiobuccal canals packed between the obturation material and the root canal wall.

Conclusions

This case report reinforces the need for treating the infected root canal as a complex system that possesses anatomic intricacies in which bacteria can spread and remain unaffected by treatment procedures.