Application of a new system for classifying tooth, root and canal morphology in the primary dentition

Three-dimensional assessment of root canal morphology of primary dentition using cone beam computed tomography

BACKGROUND

Root canal therapy in primary teeth is exceedingly complex due to the unique internal geometry of the pulp cavity.

AIM

The purpose of this study was to evaluate variations in primary teeth root canal morphology and applicability of the Ahmed et al. (Int Endod J, 50, 2017, 761) alphanumeric system for classifying them.

DESIGN

A retrospective analysis of 2024 primary teeth from an existing CBCT database was performed for assessing variations in root canal morphology. Descriptive statistics and the chi-squared test were used for data analysis.

RESULTS

The maxillary canines exhibited splitting levels of 5.9% (right) and 6.6% (left), and merging levels of 1% (both sides); maxillary lateral incisors showed splitting levels of 2.6% (right) and 0.8% (left), with no merging observed; mandibular second molars had splitting levels of 1.5% (right) and 0.8% (left), with no merging observed; and mandibular lateral incisors exhibited a merging level of 0.9% (right), with no splitting observed.

CONCLUSION

This study provides new insights into the variations in root canal morphology of primary teeth, particularly highlighting the variations found in primary canines. The Ahmed et al. (Int Endod J, 50, 2017, 761) classification system was found to be a useful tool for categorizing these variations.

Influence of the incorporation of small-group practical seminars to a traditional lecture for the understanding of root canal morphology classification systems

INTRODUCTION

This study aimed to assess if the incorporation of small-group practical seminars into a traditional lecture format improved the understanding and learning of the root canal classification systems in undergraduate students.

MATERIALS AND METHODS

A small-group practical seminar was designed for 3rd year undergraduate students. The seminar consisted of the analysis of a guided summary of root canal morphology classifications, a participative discussion of several cases and drawing exercises of several internal anatomies based on the different classifications in templates presenting the external anatomy of different dental groups. Students were inquired about their perspectives on the different classifications and the learning strategies with an anonymous questionnaire. The knowledge acquired was assessed in an exam. The scores obtained were compared using the Mann-Whitney U-test with those obtained in the cohort of the previous year in which only the traditional lecture was delivered.

RESULTS

Students' scores (mean = 7.7; SD = 2.5) were significantly higher (p = .006) than those from the previous cohort (mean = 6.9; SD = 2.3). Most students agreed that Ahmed's classification system was the most complete (98.8%) and intuitive (84%), but also the most difficult to understand (67%). All the students believed that the learning activity helped them understand the new classification system.

CONCLUSION

The incorporation of small-group practical seminars into traditional lecture improved the understanding and learning of root canal configurations in undergraduate students. Students rated the classification system suggested by Ahmed et al. as the most complete and intuitive out of the three systems, but also the most difficult to learn.

Root canal conicity determination of primary second molars using nanotomography: An in vitro study

BACKGROUND

The conicity of the root canals of primary teeth is an important measure for endodontic therapies. However, determining this conicity depends on the methods employed, which requires further investigation.

AIM

The aim of this study was to determine the conicity of the root canals of the upper and lower primary second molars using nanotomography (nCT).

DESIGN

An in vitro study was performed using nine primary second molars, both upper and lower, subjected to nCT. Comparisons between the diameters of root canals were performed between the thirds (cervical-D0, middle-D5, and apical-D7). The conicity (%) was determined for each root canal from cervical to apical. Data were statistically analyzed with a significance level of 5%.

RESULTS

The conicity ranged from 2% to 8% for the upper primary second molars. Significant differences in root canal diameter between the thirds (D0, D5, and D7 points) were observed in the mesio- and distobuccal roots (p < .05), but not in the palatal roots (p > .05). For the lower primary second molars, the conicity ranged from 2% to 17%, as well as significant differences in root canal diameter between the thirds (D0, D5, and D7 points) were observed in all roots (distal, mesiobuccal, and mesiolingual; p < .05).

CONCLUSION

The conicity of the upper primary second molars was different from that of the lower ones, which showed a greater variability.

Three-dimension model of root canal morphology of primary maxillary incisors by micro-computed tomography study

The success of root canal treatment for deciduous teeth depends upon the shape of the root canal, among other factors. Despite this, there are limited reports on the use of high-resolution micro-CT to describe the root canal morphology of primary maxillary incisors. In this study, we aimed to create a three-dimensional (3D) digital model of the root canal morphology of primary maxillary incisors using microcomputed tomography (micro-CT). To provide a reference for the development of restorative posts for the primary maxillary incisors. Primary maxillary central and lateral incisors (n = 10 each) were analysed. Micro-computed tomography was used to conduct 3D analyses of the root canal system of the primary maxillary incisors. The canal volume and surface area of the primary maxillary central incisors were larger than those of the primary maxillary lateral incisors. The structural model index value was significantly lower in central incisors. At the cervical level and the interface between the cervical and middle one-third cross-sectional levels, the root canals of the primary maxillary lateral incisors were significantly rounder. The labio-palatal dimension and the diameters of the central incisors at the four different levels were significantly smaller than the diameter of the mesio-distal dimension. The taper of the central and lateral incisors gradually increased from the apical one-third to the cervical one-third in the labio-palatal dimension. The data obtained from the 3D analysis of maxillary incisors in this study will contribute to the design of root canal posts.

Introduction of "qpdb" teeth numbering system

This manuscript introduces a new method for teeth numbering system. The primary rationale of lunching this system was to solve previous numbering systems' drawbacks. Furthermore, to keep simplicity and ease of reading and inputting data. The outcome of a questionnaire disseminated among 66 personnel showed the confusion existing among currently used tooth numbering systems. The 'qpdb' system divided the oral cavity into four quadrants, each quadrant represented by alphabetical English letter (q, p, d & b). In spite of being a promising system, this new system lacks the real usage and application, and need more future studies to prove its validity.

Estimation of root canal conicity of deciduous canines evaluated by nano-CT

PURPOSE

To estimate the taper of root canals of deciduous maxillary and mandibular canines by nano computed tomography (nano-CT).

METHODS

This in vitro study involved CT scan analysis of nine maxillary and five mandibular primary canines. The images of each tooth were reconstructed using OnDemand3D software. Thereon, diameter and taper analyses were performed on the free FreeCAD 0.18 software for the three-dimensional (3D) computer-aided design model. Statistical analysis was conducted using Stata v14.0 software, adopting a significance level of 5%.

RESULTS

3D image reconstruction was performed, considering the diameters obtained along the entire length of the tooth root, and the conical model was built with a height of 10 mm. The diameters of the maxillary canine at points D0 (0 mm), D5 (5 mm), D7 (7 mm), and D10 (10 mm) were 1.62, 1.07, 0.78, and 0.49 mm, respectively, with a significant difference between the four points (p = 0.0001). Regarding maxillary canine root taper values in the cervical, middle, and apical regions, the values were 12%, 14%, and 10%, respectively. For mandibular canines, the mean diameter values obtained at points D0, D5, D7, and D10 were 1.51, 0.83, 0.64, and 0.45 mm, respectively, with significant differences among the four points (p = 0.005). The inferior canine root tapers in the cervical, middle, and apical regions were 14%, 10%, and 6%, respectively.

CONCLUSION

The detailed knowledge of the root morphology of maxillary and mandibular deciduous canines, as it has been shown in vitro using nano-CT, is critical to achieve accurate and efficient endodontic treatments.

Evaluation of the Antibacterial Efficacy of QMix and AgNP Solutions in Root Canals of Primary Molars: An In-Vitro Study

Purpose

The study aimed to evaluate QMix²ⁱⁿ¹ and silver nanoparticles (AgNPs) solution in eliminating Enterococcus faecalis (E. faecalis) bacteria within root canals of primary molars.

Materials and methods

The study sample consisted of 45 extracted primary molars, which were divided into three groups: Group 1 (control) NaOCl 5.25%, Group 2 (experimental) QMix^{2 in 1}, and Group 3 (experimental) AgNPs 4000 ppm. The root canals were sterilized within an autoclave and then contaminated with E. faecalis bacteria. The root canals were irrigated for five minutes in a quantity of 3 ml using a 31-gauge irrigation needle, and then bacterial smears were taken.

Results

Sodium hypochlorite, AgNPs, and QMix²ⁱⁿ¹ effectively reduced the bacterial count of Enterococcus within root canals of primary molars. There were statistical differences between all groups. QMix²ⁱⁿ¹ solution showed the greatest antibacterial efficacy, then NaOCl solution and AgNPs solution. 

Conclusion

All irrigation solutions used are effective in eliminating E. faecalis. QMix²ⁱⁿ¹ can be considered a good alternative to sodium hypochlorite in irrigation root canals of primary teeth.

An approach of preserving a mandibular primary second molar by a hemisection procedure: A case report with 36-month follow up

Primary teeth play a crucial role in functional, aesthetic and speech tasks. They are also responsible for maintaining the jaw space for successor permanent teeth. Thus, dentists should understand that extraction might be the easiest decision but not always the correct one, especially, in the case of multiple loss of primary molars. On the other hand, endodontic treatments should be accurately diagnosed - necrotic and irreversibly inflamed teeth - and performed with suitable dental tools and materials. Then it is important to provide a good sealing with a suitable final restoration. This case report discusses an approach for preserving a mandibular primary second molar which had a radiographic lesion in the mesial root and the furcation area with multiple loss of primary molars (before eruption of first permanent molar). This treatment was done by performing a root canal treatment (pulpectomy) just for the distal root and a hemisection procedure by extracting the mesial root, followed by applying SSC crown and space maintainer (band and loop). To conclude, this type of treatment should be temporary until the eruption of the first permanent molar and then changed to be a lingual arch appliance. Moreover, hemisection was a suitable alternative approach to extraction over 36 months of following up.

Cone-Beam Computed Tomography (CBTC) Applied to the Study of Root Morphological Characteristics of Deciduous Teeth: An In Vitro Study

Pulp therapy in primary teeth is a challenge for a dentist, therefore, a better understanding of the anatomical characteristics of this tissue is essential to remedy these deficiencies. The aim of this study was to determine the morphological peculiarities of the root canals of extracted deciduous molars by Cone-Beam computed tomography (CBCT). As such, healthy molars without physiological resorption were collected and sanitized. After analyzing descriptive and inferential statistics, the results show that 56% of lower molar roots have a Weine’s type III canal configuration; the upper and lower second molars are significantly larger compared to the first, with a mean of 8.318 (±1.313) mm and 7.757 (±1.286) mm, respectively. Additionally, the palatine canals exhibited greater volume than the others, with a mean of 3.687 mm³. There are multiple discrepancies in the molars that have been studied in other investigations. The presence of a supernumerary root in the mandibular molars, a smaller dimension of the root canals and a more evident apical angulation are more obvious. The discovery of great anatomical versatility in the posterior dental group is an aspect applicable to root therapy.

Are electronic apex locators accurate in determining working length in primary teeth pulpectomies? A systematic review and meta-analysis of clinical studies

BACKGROUND

The lack of a well-defined apical constriction in primary teeth raises concerns regarding the accuracy of electronic apex locators (EALs) for measuring working length.

OBJECTIVES

To evaluate the accuracy of EALs in determining working length in primary teeth pulpectomies.

METHODS

Two reviewers searched ten databases up to September 2021. Clinical studies evaluating the accuracy of the electronic measurement of working length in primary teeth pulpectomies were included. Studies without a comparison group, with samples smaller than ten root canals, and that did not use a multiple frequency EAL were excluded. A meta-analysis was conducted to assess the paired differences in mean lengths between measurements obtained by electronic and comparative methods. In addition, a meta-analysis of proportion was applied according to the level of difference between the measures. The risk of bias and applicability of the studies were assessed using the QUADAS-2 tool. The certainty of evidence was assessed with the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Twenty-nine studies were included in the qualitative analysis and twenty-three in the quantitative analysis. The methods of comparison for the electronic measurement were the radiographic method, radiovisiographic, scanning electron microscopy, and direct visualization. The meta-analysis showed that the electronic measurement tends to be shorter than radiographic measurement, while the other methods showed no difference. The proportion analysis showed a higher pooled proportion of difference values between electronic and comparative measurements within -0.5 to +0.5 mm (69.31%). The certainty of the evidence suggested very low confidence in estimating the outcome.

DISCUSSION

The results of this review denote a good performance of the EALs in determining working length in primary teeth pulpectomies. However, these results are based on clinical studies with low methodological quality and high heterogeneity, which require careful interpretation for clinical practice.

CONCLUSIONS

Although the results suggest acceptable accuracy of EALs in determining working length in primary teeth pulpectomies, the low quality of the included studies and the very low certainty of the evidence require clinicians to interpret these results with caution. More robust evidence is required to support that these devices are accurate for primary teeth.

Root and Root Canal Anatomy of Primary Mandibular Central Incisor, Lateral Incisor, and Canine in Indian Children: A Cone Beam Computed Tomography Study

Background. A thorough knowledge of root and root canal morphology in primary dentition is essential for success of endodontic therapy. This information also finds importance in anthropological research in reconstructing human population history. Lack of studies of root and root canal morphology in mandibular anterior teeth prompted us to the present study. Methods. A total of 109 extracted primary mandibular incisors and canines were collected, out of which 90 teeth were selected for this study and divided into 3 groups: CI, mandibular central incisor; LI, mandibular lateral incisor; C, mandibular canine. All the sample teeth were scanned using cone beam computed tomography (CBCT). Number of roots, number of root canals, length of root, mesiodistal (MD), and buccolingual (BL) width of canal, shape of canal, and presence of accessory canals were assessed. Collected data were statistically compared using one-way ANOVA and chi-square tests. Results. All teeth studied displayed single root with single root canal conforming to type I Vertucci’s classification. Root length of CI was significantly shorter than both LI and C, with no significant difference between LI and C. Straight root canals were more common in CI and LI, whereas curved canals were more common in C. S-shaped canals were seen in a few CI and C. BL canal width was more than MD width in all teeth, C showing significantly larger dimensions than both CI and LI. Conclusion. This study presents root and root canal characteristics of primary mandibular central incisor, lateral incisor, and canine in children from Indian ethnicity.

Comparative Analysis of Root Canal Dentin Removal Capacity of Two NiTi Endodontic Reciprocating Systems for the Root Canal Treatment of Primary Molar Teeth. An In Vitro Study

The objective of the present study was to evaluate and compare the dentin removal capacity of Endogal Kids and Reciproc Blue NiTi alloy endodontic reciprocating systems for root canal treatments in primary second molar teeth via a micro-computed tomography (micro-CT) scan. Materials and Methods: Sixty root canal systems in fifteen primary second molar teeth were chosen and classified into one of the following study groups: A: EK3 Endogal Kids (n = 30) (EDG) and B. R25 Reciproc Blue (n = 30) (RB). Preoperative and postoperative micro-CT scans were uploaded into image processing software to analyze the changes in the volume of root canal dentin using a mathematical algorithm that enabled progressive differentiation between neighboring pixels after defining and segmenting the root canal systems in both micro-CT scans. Volumetric variations in the root canal system and the root canal third were calculated using a t-test for independent samples or a nonparametric Mann–Whitney–Wilcoxon test. Results: Statistically significant differences (p = 0.0066) in dentin removal capacity were found between the EDG (2.89 ± 1.26 mm³) and RB (1.22 ± 0.58 mm³) study groups for the coronal root canal third; however, no statistically significant differences were found for the middle (p = 0.4864) and apical (p = 0.6276) root canal thirds. Conclusions: Endogal and Reciproc Blue NiTi endodontic reciprocating systems showed similar capacity for the removal of root canal dentin, except for the coronal root canal third, in which the Reciproc Blue NiTi endodontic reciprocating system preserved more root canal dentin tissue.

Effectiveness of antimicrobial photodynamic therapy as an adjunct to mechanical instrumentation in reducing counts of Enterococcus faecalis and Candida albicans from C-shaped root canals

BACKGROUND/PURPOSE

The aim was to assess the effectiveness of antimicrobial photodynamic therapy (aPDT) as an adjunct to mechanical instrumentation (MI) in reducing Enterococcus faecalis (E faecalis) and Candida albicans (C albicans) counts from C-shaped root-canals.

METHODS

Teeth with C-shaped canals as identified on cone beam computed tomographic images were included. Following incubation with E faecalis and C albicans, samples were divided into 4 groups a four follows: Group-1: MI with adjunct aPDT; Group-2: aPDT alone; Group-3: MI alone; and Group-4: no treatment. The pulp chambers of these teeth were exposed and coronal pulp was mechanically derided using sterile endodontic excavators. Using flexible files, all canals were debrided up to size #30 K-files with intermittent irrigation with 2.5% sodium hypochlorite irrigation. In Groups 1 and 3, methylene-blue was injected in all canals and aPDT was performed using a 600 nm diode laser. Sample-size estimation was done on data from a pilot investigation and group-comparisons were done using one way analysis of variance and Bonferroni post-hoc adjustment tests. P < .05 was considered statistically significant.

RESULTS

Sixty periodontally hopeless mandibular second molars with C-shaped canals were included. There was a statistically significant reduction CFU/mL of E faecalis (P < .001) and C albicans (P < .001). At post-operative microbial assessments in Group-1. There was no difference CFU/mL of E faecalis and C albicans at post-operative microbial assessments in Groups 2-4.

CONCLUSION

MI with adjunct aPDT is more effective in reducing count of E faecalis and C albicans from C-shaped root canals.

Prevalence of Three-Rooted Deciduous Mandibular Molars in the Children of Northwestern Iran

Introduction

Although primary teeth have a determinative role in development of normal occlusion, few studies about anomalies related to deciduous dentition have been conducted so far. Regarding recent improvements in common knowledge and the importance of maintaining primary teeth until eruption of succedaneous teeth, identifying the morphology of primary teeth and probable variations is of great importance to achieve optimal therapeutic outcome. This study aims to determine the prevalence of three-rooted mandibular primary molars in a population of northwestern Iran.

Materials and Methods

In this descriptive cross-sectional study, periapical radiographs of patients attending private oral and maxillofacial radiology offices in the northwestern region of Iran from 2017 to 2019 were retrospectively reviewed. A total of 300 cases in the 3-10-year age range having bilateral periapical radiographs from mandibular primary molars were screened. First and second primary molars were observed meticulously. Gender, side of the mandible (right or left), symmetry, overall prevalence, and prevalence considering the type of molar (D or E) were recorded and analyzed.

Results

Overall prevalence of three-rooted mandibular primary molars was 9.33% ( 28/300), 92.9% of which were unilateral. The prevalence of teeth showing supernumerary roots among all teeth examined was 2.5% (30/1200). Considering symmetry and gender, the occurrence of these three-rooted primary molars did not differ significantly (respectively, p=0.832 and p=0.541). However, there was a significant relationship between the occurrence of supernumerary roots and left side for three-rooted first molars and right side for three-rooted second molars (p=0.021).

Conclusion

Obtained data show that three-rooted mandibular primary molars in children of northwest region of Iran have a prevalence of approximately 10 % which urges some specific considerations in exodontic and endodontic procedures.

Comparison of two pediatric rotary file systems and hand instrumentation in primary molar: An ex vivo cone-beam computed tomographic study

Background

Pulpal involvement, secondary to dental caries, is not uncommon and is a challenging task for pediatric dentists. Morphological differences in root canal of deciduous teeth increases the complexity of management. The aim of this study was to compare two rotary file systems and hand instrumentation for root canal preparation in regard to canal transportation, centering ability ratio, and dentin thickness using cone-beam computed tomography (CBCT).

Methods

A total of 72 canals from 24 freshly extracted mandibular deciduous second molars were divided into a set of 8 teeth, then prepared using 2 rotary files systems: the Kedo-S pediatric file system (Group A) and Pro AF Baby Gold file system (Group B) were compared to hand instrumentation (Group C). CBCT scans before and after root canal preparation were used to evaluate tested parameters. Instrumentation time for all three techniques was also measured using a chronometer.

Results

Although rotary file systems have shown superior results in root canal preparation as compared to hand instrumentation, no significant differences were observed between all the groups for canal transportation and dentin thickness at all three levels of prepared canals. A comparison of centering ability ratio between all the groups was found to be statistically significant only at the cervical level. A significant difference was observed between hand instrumentation using K-files (117.3 s) and both rotary systems (Kedo-S (81 s) and Pro AF Baby Gold (81.5 s)) in terms of canal preparation time (P < 0.001).

Conclusions

Both tested rotary systems and hand instrumentation demonstrated comparable canal preparation results, with differences that were statistically non-significant in most tested parameters, without shaping errors. However, both the rotary systems were more efficient and faster than hand instrumentation.

Application of a new system for classifying root and canal anatomy in studies involving micro-computed tomography and cone beam computed tomography: Explanation and elaboration

Adequate knowledge and accurate characterization of root and canal anatomy is an essential prerequisite for successful root canal treatment and endodontic surgery. Over the years, an ever-increasing body of knowledge related to root and canal anatomy of the human dentition has accumulated. To correct deficiencies in existing systems, a new coding system for classifying root and canal morphology, accessory canals and anomalies has been introduced. In recent years, micro-computed tomography (micro-CT) and cone beam computed tomography (CBCT) have been used extensively to study the details of root and canal anatomy in extracted teeth and within clinical settings. This review aims to discuss the application of the new coding system in studies using micro-CT and CBCT, provide a detailed guide for appropriate characterization of root and canal anatomy and to discuss several controversial issues that may appear as potential limitations for proper characterization of roots and canals.

Root and Root Canal Morphology Classification Systems

Introduction

While there are many root morphology classification systems with their own distinct advantages, there are many shortcomings that come along with each system.

Objectives

The aim of this review was to compare the various root and root canal morphology classifications, their advantages, limitations, and clinical and research implications. Data Sources and Selection. An extensive literature search was conducted on PubMed and Scopus to identify the published data on root and root canal classification systems published until 1 May 2020 using keywords, root canal classification system, classification systems for root canals, and root morphology. The related literature was reviewed and then summarized. Data Synthesis. Several studies have analysed and detailed root and root canal classifications and further added new subsystems, works of Weine et al. (1969) and Vertucci et al. (1974). Besides, Sert and Bayirli (2004) added supplementary types to Vertucci's classification system. A new classification was most recently introduced by Ahmed et al. (2017) involving the use of codes for tooth numbering, number of roots, and canal configuration.

Conclusions

Weine et al. classified only single-rooted teeth, without considering multirooted teeth and complex configurations. Vertucci's classification included complex configurations, with Sert and Bayirli adding further complex supplemental types. Ahmed et al.'s classification simplifies classifying root and canal morphology while overcoming the limitations of several previous classification systems making it beneficial for implementation in dental schools.

Detection of the internal anatomy of lower anterior teeth using cone-beam computed tomography

Morphology study of root canal systems is essential for a correct diagnosis, therapy and prognosis of root canal treatment. This study aimed to analyse the dental anatomy of the lower anterior teeth, using cone-beam computed tomography (CBCT). Lower anterior teeth were classified in terms of type, number and location of root canals, evaluating the bilaterality of anatomical occurrences and determining whether the gender and age influence the findings. We analysed 749 CBCT of patients attending the School of Dentistry for different reasons. Spearman's correlations and Wilcoxon signed-rank test were used to analyse data (α = 0.05). There was no significant correlation between gender (male and female) and anatomy of the canals 33 (P = 0.162), 32 (P = 0.815), 31 (P = 0.708), 41 (P = 0.422), 42 (P = 0.382) and 43 (P = 0.063). There was a significant correlation between age and anatomy of the canals 33 (P = 0.045), 32 (P = 0.033), 31 (P = 0.022), 41 (P = 0.000), 42 (P = 0.037) and 43 (P = 0.037). There was no significant correlation between gender and patients' age (P = 0.325). There was no anatomical difference between the bilateral pairs (right and left homologous teeth) (P > 0.05). The most common anatomical configuration was single-canal teeth (85.29%), followed by the configuration in which one canal leaves the chamber, divides into two and unite again (12.88%). Anatomy of the lateral incisors and lower canines does not change with the gender of patients. However, as age rises, single canals and the incidence of division into two canals ending in a single foramen also increases.

Flowable Urethane Dimethacrylate-Based Filler for Root Canal Obturation in Primary Molars: A Pilot SEM and microCT Assessment

Pulpectomy in deciduous teeth involves endodontic access opening, root canal debridement and obturation with an appropriate filling material. EndoREZ (ER) is the urethane dimethacrylate-based filler, which can be used for root canal obturation in permanent and primary teeth. This observation aimed to evaluate the behavior of the ER as a filler in root canals of two primary molars after the physiological resorption process using the scanning electron microscopy (SEM) and micro-computed tomography (µCT) in second lower molars after their natural exfoliation. The SEM analysis revealed a non-uniform, porous and lacunary structure of ER, visually similar to the resorbed surface of the dentine. The µCT observations demonstrated the differences in the resorption level of the root and material surfaces. The preliminary observations suggest that ER is resorbed faster than root tissues and can therefore be a suitable material for the root canal filling in primary teeth. However, more investigations are needed to support these preliminary findings.

Root canal conicity estimation of primary maxillary central and lateral incisors-A study by Nano-CT

AIM

The objective of the study was to estimate the conicity of the root canals of maxillary central and lateral incisors by computed nanotomography (Nano-CT).

DESIGN

This in vitro study included nine extracted primary maxillary central incisors and 12 maxillary lateral incisors, which were subjected to Nano-CT analysis. The resulting images of each tooth were reconstructed using the OnDemand3D software, and root canal area, volume, and taper analysis were performed using the free FreeCAD 0.18 software for the 3D computer-aided design (CAD) model. Data were statistically analysed using the Stata v14.0 software, adopting a significance level of 5%.

RESULTS

The results presented the mean value of the diameter and area of the root canal of primary central and lateral incisors. In addition, the taper values for both dental groups between points D0-D5, D5-D7, and D7-D10 were determined. Considering the diameters obtained over the entire length of the root, with a length of 12 mm, a conical model was constructed.

CONCLUSION

Detailed knowledge of root morphology of maxillary central and lateral incisors of primary dentition by means of Nano-CT is important to achieve faster, more accurate, and efficient endodontic treatments.