Clinical decision-making and importance of the AAE/AAOMR position statement for CBCT examination in endodontic cases

Construction and evaluation of an AI-based CBCT resolution optimization technique for extracted teeth

INTRODUCTION

In dental clinical practice, cone-beam computed tomography (CBCT) is commonly used to assist practitioners to recognize the complex morphology of root canal systems. But due to its resolution limitations, certain small anatomical structures still cannot be accurately recognized on CBCT. The purpose of this study was to perform image super-resolution (SR) processing on CBCT images of extracted human teeth with the help of a deep learning model, and to compare the differences among CBCT, SRCT, and micro-computed tomography (Micro-CT) images through three-dimensional reconstruction.

METHODS

The deep learning model （Basicvsr++） was selected and modified. The dataset consisted of 171 extracted teeth that met inclusion criteria, with 40 maxillary first molars as training set and 40 maxillary first molars as well as 91 teeth from other tooth positions as external test set. The corresponding CBCT, SRCT, and Micro-CT images of each tooth in test sets were reconstructed using Mimics Research 17.0, and the root canal recognition rates in the three groups were recorded. The following parameters were measured: volume of hard tissue(V1), volume of pulp chamber and root canal system(V2), length of visible root canals under orifice(VL-X, where X represents the specific root canal), intersection angle between coronal axis of canal and long axis of tooth(∠X, where X represents the specific root canal). Data were statistically analyzed between CBCT and SRCT images using paired sample t-test and Wilcoxon test analysis, with the measurement from Micro-CT images as the gold standard.

RESULTS

Images from all tested teeth were successfully processed with super-resolution program. In 4-canal maxillary first molar, identification of MB2 was 72% (18/25) in CBCT group, 92% (23/25) in SRCT group, and 100% (25/25) in Micro-CT group. The difference of hard tissue volume between SRCT and Micro-CT was significantly smaller than that between CBCT and Micro-CT in all tested teeth except 4-canal mandibular first molar (P < 0.05). Similar results were obtained in volume of pulp chamber and root canal system in all tested teeth (P < 0.05). As for length of visible root canals under orifice, the difference between SRCT and Micro-CT was significantly smaller than that between CBCT and Micro-CT (P < 0.05) in most root canals.

CONCLUSIONS

The deep learning model developed in this study helps to optimize the root canal morphology of extracted teeth in CBCT. And it may be helpful for the identification of MB2 in the maxillary first molar.

Applying the American Association of Endodontists and American Academy of Oral and Maxillofacial Radiology guidelines for cone-beam computed tomography prescription: Impact on endodontic clinical decisions

BACKGROUND

The American Association of Endodontists (AAE) and the American Academy of Oral and Maxillofacial Radiology (AAOMR) developed guidelines for the prescription of cone-beam computed tomographic (CBCT) imaging. The impact of appropriately prescribed CBCT imaging on endodontic diagnosis and treatment (Tx) decisions was examined.

METHODS

The clinical databases at the School of Dentistry at the University of California, Los Angeles, Los Angeles, California, were queried to identify patients referred for CBCT imaging from the postgraduate endodontic clinic over a consecutive 36-month period. Primary and secondary indications for CBCT imaging were recorded. Pre-CBCT uncertainty in diagnosis, Tx of the teeth in question, and post-CBCT changes to the diagnosis and Tx plan were recorded.

RESULTS

CBCT imaging was prescribed for 12% of patients. A total of 442 scans were prescribed to evaluate 526 teeth. Molars accounted for 51% of teeth examined. Overall, CBCT effected a change in periapical diagnosis (21%) and in the Tx plan (69%). The 5 most frequent primary indications for CBCT imaging were, in order, AAE-AAOMR recommendations 7, 9, 2, 12, and 6. The impact of these recommendations on Tx decisions varied from 48% through 93%.

CONCLUSIONS

This study validates the use of the AAE-AAOMR guidelines for prescribing CBCT imaging for endodontic evaluations. CBCT imaging contributed predominantly to Tx decisions rather than diagnostic determinations.

PRACTICAL IMPLICATIONS

This study validates AAE-AAOMR case selection guidelines for CBCT imaging and shows a positive impact of prescription imaging on endodontic decision making.

Morphometric relationships in mesio-buccal roots of maxillary first molars in Saudi subpopulation: A CBCT study

This CBCT-based study analysed morphometric relationships in Mesio-Buccal (MB) roots of maxillary first molars (MFM). 133 MFM with two MB canals were assessed and classified using Vertucci's classification. MB roots' length and MB1-MB2 canals inter-orifice distances (IOD) were noted. The data were analysed using SPSS software. The most frequently present canal was type IV (59.4%) followed by type II (40.6%). Mean MB roots' length for canals exhibiting type IV was 9.26 ± 0.21 mm and of those exhibiting type II was 12.8 ± 0.42 mm. Statistically significant relationship was found between MB root length and canal type. Mean IOD for type II and type IV canals was 2.4 ± 0.47 and 3.8 ± 0.21 mm, respectively. Statistically significant relationship was found between IOD and canal type. Length of MB root and IOD had a significant association with canal type present in MFM. This knowledge can enhance clinicians' understanding of canal morphology which can increase predictability and success rate of endodontic treatment.

Concurrency of additional canals in mandibular incisors and second mesiobuccal canal in maxillary first molars: A cone-beam computed tomography investigation

This study investigated the concurrency of additional canals in mandibular incisors and the second mesiobuccal canal in maxillary first molars among the Chinese population. In total, 8644 cone-beam computed tomography images from 8644 patients with bilateral mandibular incisors and maxillary first molars were examined. The data were analysed using Chi-square test, binary logistic regression analysis and receiver operating characteristic curve. Among the patients with additional canals in mandibular central and lateral incisors, 96.2% and 95.5% of them had second mesiobuccal canal in maxillary first molars, respectively. Additional canals of mandibular incisors and second mesiobuccal canal in maxillary first molars exhibited a concurrent relationship. The prevalence of second mesiobuccal canal in maxillary first molars increased with the number of mandibular incisors with additional canals. Moreover, when there was at least one mandibular incisor with additional canals, the presence of the second mesiobuccal canal in maxillary first molars could be highly expected.

Endodontic Orthograde Retreatments: Challenges and Solutions

Endodontic orthograde retreatments are considered one of the possible treatment options in case of post-treatment diseases considering the promising results present in the literature. Despite this, a plethora of articles have been published on this topic, and drawing conclusions could be challenging. For this reason, this review aims to summarize the crucial points on each aspect of non-surgical endodontic retreatments, discussing and comparing the current protocols, techniques, materials, and indications. Taking into consideration data from the literature, in terms of diagnosis, CBCT should be considered the first choice, since it can thoroughly affect the diagnosis and treatment plan. Regarding the procedural phases, some conclusions can be drawn: when present, coronal restoration materials such as crowns, partial prostheses, post, and core should be removed; the use of magnification devices, ultrasonic instruments, and an in-depth interpretation of radiographic images with both 2D and 3D images are strongly recommended during the orifice location; additional protocols such as irrigants activation, ultrasonic cleaning, and rotary or reciprocating instrumentation of treated canals are strongly recommended for filling materials removal and to achieve a high-quality chemo-mechanical disinfection; perforations should be treated as soon as possible, and the material of choice to treat them is the MTA or other calcium-silicate-based repair materials; the presence of ledges does not intrinsically reduce the success rate of RCRts if properly managed; in case of instrument fragments, their removal should be considered as the first treatment option, however many variables should be considered to select the proper technique or consider the option of bypassing.

Cone-beam computed tomographic reconstructions in the evaluation of maxillary impacted canines

Purpose

Prior to cone-beam computed tomography (CBCT), orthodontic competence included radiological interpretation. Nevertheless, maxillary impacted canines (MICs), because of their position and adjacent complex anatomy, have been challenging to interpret, particularly with regard to root resorption. Although CBCT cross-sectional reconstructions of MICs yielded clearer insights into its diagnosis and treatment planning, the value of simultaneously using 2 different cross-sectional or multiplanar reconstructions of the CBCT datasets - orthogonal and curved/panoramic multiplanar reconstructions - has hitherto not been considered.

Materials and Methods

Both orthogonal and curved/panoramic multiplanar reconstruction series of 5 screenshots were each reconstructed from the 5 cm × 5 cm CBCT datasets of 15 separate MICs. Fifteen credentialled and experienced orthodontist volunteers reviewed 2 separate PowerPoints of 15 randomized series each, 1 week apart. Their review considered 6 factors that could affect treatment: the position and level of the MIC, the presence or absence of root resorption, ankylosis, cysts, and dilaceration.

Results

All 15 orthodontists were statistically similar regarding overall years of experience and of CBCT use. Although either reconstruction alone allowed the orthodontists to determine whether ankylosis and, to a lesser extent, most of the other features were present or absent in the MIC, reviewing both reconstructions together was necessary to determine whether root resorption was present or absent in the adjacent tooth.

Conclusion

Reviewing both orthogonal and curved/panoramic multiplanar reconstructions was necessary to evaluate the presence or absence of root resorption in the teeth adjacent to MICs and that of many other features.

Effect of field of view and voxel size on CBCT-based accuracy of dynamic navigation in endodontic microsurgery: an in vitro study

INTRODUCTION

This study aimed to evaluate the influence of field of view (FOV) and voxel size on the accuracy of dynamic navigation (DN)-assisted endodontic microsurgery (EMS).

METHODS

Nine sets of maxillary and mandibular three-dimensional-printed jaw models composed of 180 teeth were divided into nine groups with different FOVs (80 × 80 mm, 60 × 60 mm, and 40 × 40 mm) and voxel sizes (0.3, 0.16, and 0.08 mm). The endodontic DN system was used to plan and execute the EMS. The accuracy of the DN-EMS was represented by the platform deviation, end deviation, angular deviation, resection angle, and resection length deviation. Statistical analyses were performed using SPSS 24.0, and the significance level was set at p < 0.05.

RESULTS

The average platform, end, angular, resection angle, and resection length deviation were 0.69 ± 0.31 mm, 0.93 ± 0.44 mm, 3.47 ± 1.80°, 2.35 ± 1.76°, and 0.41 ± 0.29 mm, respectively. No statistically significant differences in accuracy were observed between the nine FOV and voxel size groups.

CONCLUSION

FOV and voxel size did not appear to play an important role in the accuracy of DN-EMS. Considering the image quality and radiation dose, it is reasonable to select a limited FOV (such as 40 × 40 mm and 60 × 60 mm) to cover only the registration device, involved teeth, and periapical lesion. The voxel size should be selected according to the required resolution and CBCT units.

CBCT in contemporary endodontics

Cone-beam computed tomography (CBCT) is a three-dimensional imaging modality which can aid endodontic diagnosis and treatment planning. While there are guidelines available describing the indications, there are divergent philosophies on when this technology should be applied in clinical practice. This paper reviews the applications of CBCT including the clinical relevance of parameters which can be assessed, highlights the limitations of this technology, and provides guidance on how to maximise its clinical utility.

Image quality for visualization of cracks and fine endodontic structures using 10 CBCT devices with various scanning protocols and artefact conditions

The aim of this study was to evaluate CBCT exposure protocols and CBCT devices in terms of image quality for the detection of cracks and fine endodontic structures using 3 conditions of metallic artifacts. An anthropomorphic phantom containing teeth with cracks, isthmus, narrow canal, and apical delta was scanned using ten CBCT devices. A reference industrial CT image was used to detect and measure all structures. Three conditions were created: (1) metal-free, (2) 'endo' and (3) 'implant' with metallic objects placed next to the teeth of interest. For each condition, three protocols were selected: medium field of view (FOV) standard resolution, small FOV standard and high resolution. The results showed that only small FOV high-resolution metal-free images from two devices (A and H) were appropriate to visualize cracks. For fine structure identification, the best result was observed for small FOV high resolution. However, the visualization significantly worsened in the presence of metallic artefacts. The ability of CBCT images for visualizing cracks is restricted to certain CBCT devices. Once metallic artefacts are present, crack detection becomes unlikely. Overall, small FOV high-resolution protocols may allow detection of fine endodontic structures as long as there are no high-dense objects in the region of interest.

Influence of cone beam computed tomography on endodontic treatment planning: A systematic review

OBJECTIVES

The aim of this systematic review was to evaluate how treatment plans changed when cone beam computed tomography (CBCT) imaging was used in endodontic treatment decision-making.

DATA

Studies examining changes in clinicians' treatment plans with and without the use of CBCT were included. Risk of bias assessment was completed using a modification of the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool.

SOURCES

A systematic search was performed in PubMed, Embase, Scopus, Cochrane databases from inception to 14 September 2021.

STUDY SELECTION

The initial search identified 3379 titles and abstracts; 20 articles fulfilled inclusion and exclusion criteria for full text review. An additional three articles were identified through citation searching. Sixteen studies met inclusion and exclusion criteria for data extraction and analysis. Fifteen studies reported changes in treatment plan with CBCT imaging. Five studies reported changes in 45 - 66.7% of the cases but did not mention specific treatment options. Of the 11 remaining studies, 10 studies reported changes in 24.3 - 56% of cases and changes in treatment options, while one study reported no significant change in treatment plan after CBCT imaging was introduced. With CBCT imaging, clinicians were more likely to prescribe further intervention that included endodontic treatment and extractions.

CONCLUSION

Although the current evidence was heterogeneous, it was clear that CBCT offered more information than periapical radiography. This influenced endodontic treatment decision-making and in more complex cases, led to further intervention including non-surgical and surgical endodontic treatment and extractions.

CLINICAL SIGNIFICANCE

Additional information from CBCT imaging influenced endodontic treatment decision-making in the following situations: high difficulty cases, diagnosis of symptomatic teeth after failed root canal treatment, evaluation of periapical healing, pre-surgical treatment planning, and management of traumatised immature teeth and external cervical resorption.

Influence of Cone-beam Computed Tomography in clinical decision-making among different specialists in External Cervical Resorption lesions: a before-after study

INTRODUCTION

Inadequate management of external cervical resorption (ECR) lesions may impact the treatment outcome. This study aimed to ascertain the influence of cone-beam computed tomography (CBCT) in clinical decision-making choices in cases of ECR among dentistry specialists (endodontics, prosthodontics, oral surgery, periodontics orthodontics, and general dentistry). A secondary objective was to evaluate the self-reported level of difficulty in choosing a treatment plan before and after viewing the CBCT images.

METHODS

Sixty examiners from different specialties were chosen to evaluate 12 cases of ECR lesions. Each case included clinical photographs, digital periapical (PA) radiographs, and a small-volume CBCT scan. In the first assessment, the examiners were given all the relevant information of each case, except the CBCT scan. Each examiner was asked to select 1 of the proposed treatment options and assess the difficulty of decision making. Four weeks later, the examiners randomly reviewed the same 12 cases with additional information from the CBCT data.

RESULTS

After the CBCT evaluation, the clinicians changed their treatment plan in 72.2% of the cases (P < .05). The self-reported level of difficulty in choosing a treatment changed in all groups after evaluating the CBCT scans (P< .05). After viewing the CBCT scan, the extraction option increased significantly in all groups (P < .05).

CONCLUSIONS

CBCT scan had a significant impact on clinical decision-making in cases of ECR evaluated by different specialists.

"New Normal" Radiology

COVID-19, the most recent and globally impactful zoonotic viral pandemic in the last 20 years, has now entered its third year. As the global dental profession returns to providing as full a range of services as possible, in addition to embedding the new infection-control processes that were developed for this pandemic, it should also take full advantage of digital conventional radiology (intraoral, extraoral, and panoramic radiography) and cone-beam computed tomography. Regardless of vaccinations, new or yet-to-manifest variants, and testing, some dentists may be working in communities where the asymptomatic but potentially infectious patient poses a real risk. This needs to be met with not only the whole COVID-19 panoply the dentist is already too familiar with but also the need to minimise aerosol generation production by dental radiography. A flowchart and a table that compares the attributes of the above modalities are included.

Is the quality of root canal filling obtained by cone-beam computed tomography associated with periapical lesions? A systematic review and meta-analysis

AIM

To evaluate the influence of root canal filling quality on periapical lesion status using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

The bibliographic search was conducted in electronic databases of PubMed, Embase, Scopus, and Web of Science without restrictions related to the year of publication and language. Inclusion criteria were prospective or retrospective cohort studies that followed periapical pathosis for, at least, 1 year. Three reviewers independently evaluated the eligibility for inclusion, extracted data, and assessed the risk of bias. The quality of the studies was based on the Newcastle-Ottawa Scale. This meta-analysis was performed to evaluate the quality of treatment by the homogeneity and apical extension of the filling.

RESULTS

Of the 1179 studies initially recovered, six cohort studies were included, out of which four were considered with a low risk of bias. The results showed that the absence of gaps in the filling reduced the chance of unhealed periapical lesions by 2.39 times (RR = 2.39; 95% CI: 1.62-3.53; p < 0.00001; I² = 55%). An apical filling extension of 0-2 mm below the apex also contributed significantly to the absence of unhealed periapical lesions (RR = 1.49; 95% CI: 1.15-1.94; p = 0.003; I² = 2%).

CONCLUSION

The homogeneity and apical extension of the filling influenced the presence of unhealed periapical lesions in endodontically treated teeth evaluated using CBCT.

CLINICAL RELEVANCE

Apical extension of the filling ranging between 0 and 2 mm short of the apical foramen and the homogeneity of the filling without gaps are directly related to the success rate of root canal treatment.

Delaying Intraoral Radiographs during the COVID-19 Pandemic: A Conundrum

Background

The COVID-19 pandemic has made dentists very assiduous about cross-infection during dental treatment, thereby delaying dental radiographs for treatment. However, patients needing dental emergency treatment in the ongoing pandemic require relevant intra/extraoral dental radiography for adequate diagnosis and treatment planning.

Methods

This article is aimed at adding to the hot debate: Is delay for intraoral radiographs justified or a possible proxy? As a narrative review, it provides an insight into the reasons for delaying intra-oral dental radiographs during in the pandemic and options of the nontraditional radiographic techniques available until the pandemic subsides. Discussion and Conclusion. Cross-contamination concerns through respiratory droplets grow while using intraoral film holders that stimulate gag reflex, coughing, saliva secretion, and if proper disinfection protocols are not applied. Since the patients' acquiring emergency dental treatment cannot be neglected, the return-to-work guidelines by the health regulatory bodies urge to prioritize extraoral radiographic imaging techniques to curb the infection, offering the best diagnostic efficacy. The dental professionals can consider cone-beam computed tomography (CBCT) scans and sectional dental panoramic radiographs (SDPRs), followed by a risk assessment for COVID-19, a safer modality in reducing cross-contamination and assuring an innocuous environment for both patient and coworkers.

Mesiobuccal and Palatal Interorifice Distance May Predict the Presence of the Second Mesiobuccal Canal in Maxillary Second Molars with Fused Roots

INTRODUCTION

The aim of this study was to evaluate if the configuration of canal orifices can predict the presence of a second mesiobuccal canal (MB2) in maxillary second molars with fused roots.

METHODS

Maxillary second molars with fused roots (N = 150) were scanned in a micro-computed tomographic device (pixel size = 9 μm) and evaluated regarding the root fusion type and the incidence of the MB2 canal. The centers of the canal orifices were connected, and the angles formed by the intersection of these lines as well as their distances were measured and statistically compared (1-way analysis of variance). Specimens were then assigned to 2 groups according to the presence (n = 65) or absence (n = 50) of the MB2 canal and compared regarding the angles and interorifice distances using the Welch t test. A binary logistic regression model estimated the association between the interorifice distance, the fusion type, and the presence of the MB2 canal, whereas receiver operating characteristic curve analysis was performed to evaluate the diagnostic abilities of significant variables. The significance level was set at 5%.

RESULTS

The most common fusion types were 1 and 6, and MB2 canal incidence was 47.3%. No statistical difference was observed in the angles or interorifice distances among teeth with different fusion types (P > .05). Distances from the mesiobuccal (MB) to the distobuccal and palatal (P) canal orifices as well as the MB and P angles were significantly higher in the presence of an MB2 canal (P < .05). A binary logistic regression model revealed that MB-distobuccal and MB-P distances were significant in the presence of an MB2 canal (P < .05). Receiver operating characteristic analysis indicated that MB-P distance had acceptable diagnostic accuracy for the prediction of MB2 canal presence. Sensitivity (specificity) calculated from the MB-P distances of 4.0, 4.5, and 5.0 mm were 89.2% (36.5%), 76.9% (58.4%), and 44.4% (71.4%), respectively.

CONCLUSIONS

MB-P interorifice distance is a strong predictor of the presence of the MB2 canal in maxillary second molars with fused roots.