Limited cone-beam CT and intraoral radiography for the diagnosis of periapical pathology

Comparative assessment of periapical radiography and CBCT imaging for radiodiagnostics in the posterior maxilla

Close proximity of the maxillary roots and the sinus floor makes a dental disease a probable cause of maxillary sinusitis. The aim of this study was to evaluate the ability of periapical radiography and cone beam computed tomography in defining the topographic relationship of maxillary teeth to the sinus floor and detecting apical periodontitis and other odontogenic causes of the maxillary sinusitis. Out of 145 dental records from subjects (mean age 52 years, range 20-75 years; 89 females) referred to the Oral Imaging Centre, KU Leuven, periapical and CBCT images of the posterior maxilla were selected for further analysis. Anatomical relationship of maxillary teeth to the sinus floor, apical periodontitis and other etiological causes of soft tissue thickening were assessed with both imaging modalities. The results of this study demonstrated that periapical radiographs are not adequate in observing the anatomical relationship between maxillary molars and the sinus floor. CBCT showed an intimate relationship of 1st and 2nd molar with the maxillary sinus in 50 and 45% of the cases, respectively. Periapical radiography could only spot approximately 40% of apical periodontitis on posterior maxillary teeth and 3% of all apical infections extending to the sinus, seen on CBCT.

A comparative investigation of cone-beam computed tomography and periapical radiography in the diagnosis of a healthy periapex

INTRODUCTION

This research aimed to compare the appearance of healthy periapical tissues on cone-beam computed tomography (CBCT) with periapical radiography and to measure the periodontal ligament (PDL) space on CBCT for teeth with healthy and necrotic pulps.

METHODS

Patient records from specialist endodontic practices were examined for teeth that had a high-resolution (0.08-mm voxel) and small field-of-view CBCT scan, a periapical radiograph, and clinical pulp tests (CO2 and electric pulp testing). The periapical regions of the CBCT scans and radiographs were scored individually by 2 calibrated, blinded examiners by using a modified CBCT-periapical index (CBCT-PAI) for both and represented as CBCT-PAI and PAI, respectively. The Fisher exact and χ(2) statistics tested the relationships between CBCT-PAI, PAI, and pulp status.

RESULTS

Of 200 teeth included in the study, 166 showed clinical signs of pulpal health, and the CBCT-PAI score was greater than the PAI in 72% (119 of 166), with a vital pulp likely to have a radiographic PDL space widening of 0-1 mm (P < .001). Although 2 healthy teeth showed radiolucencies 2-4 mm on CBCT scan when the periapical radiograph showed none, a PDL space of greater than 1-2 mm was indicative of a necrotic pulp (P < .001).

CONCLUSIONS

Teeth with necrotic pulps were more likely to have PDL widening, but the PDL space of a healthy tooth demonstrated significant variation when examined by CBCT. The radiographic interpretation of health and disease on CBCT must be further investigated before usage in outcome or epidemiologic investigations. This research questions the traditional radiographic interpretation of the PDL space.

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.

Discuss the impact technological advances in equipment and materials have made on the delivery and outcome of endodontic treatment

Recent advances in endodontic equipment and materials have considerably changed the manner in which endodontic treatment is delivered. Specific technological advances, including nickel-titanium instruments, ultrasonic instruments and the dental operating microscope have been associated with increased efficiency and efficacy of treatment and simplification of delivery. The effects of most of these changes have been tested via in vitro studies and case reports. Ongoing studies should constantly investigate what effects technological advances might have on the outcome of endodontic treatment.

Periapical lucency around the tooth: radiologic evaluation and differential diagnosis

Periapical lucencies are often seen incidentally at head and neck imaging studies performed for indications not related to the teeth. These lesions are, however, occasionally manifestations of diseases that have a wide range of effects and may at times represent the source of symptoms that prompted the study. The vast majority of periapical lucencies are the result of apical periodontal or pulpal disease. If found in an advanced state or left untreated, disease related to the tooth may spread to adjacent tissues, including the sinuses, orbits, deep fascial spaces of the neck, and intracranial structures, and result in a significant increase in patient morbidity and mortality. Although the majority of periapical lucencies seen on radiographs and computed tomographic images occur secondary to apical periodontal or pulpal disease, not all lucencies near the tooth root are due to infection. Lucency near the tooth root may be seen in the setting of other diseases of odontogenic and non-odontogenic origin, including neoplasms. Although imaging findings for these lesions can include periapical lucent components, awareness of the varied secondary imaging features can aid the radiologist in developing an accurate differential diagnosis. Familiarity with the imaging features and differential diagnoses of diseases or conditions that cause lucency around the tooth root results in appropriate referral and prompt diagnosis, management, and treatment, and can prevent unnecessary additional imaging or intervention. In addition, early recognition and appropriate treatment of infectious processes will result in improved clinical outcomes and a decrease in morbidity and mortality.

Comparative diagnostic yield of cone beam CT reconstruction using various software programs on the detection of vertical root fractures

OBJECTIVES

To evaluate the effect on diagnostic yield in the detection of experimentally induced vertical root fractures on cone beam CT images using four dental software program.

METHODS

190 single-rooted extracted human teeth were divided into three groups according to the pulp canal status: unrestored (UR), filled with gutta-percha (GP) and restored with a metallic custom post (Post). One-half of the sample of each group was artificially fractured and the segments repositioned. All teeth were scanned on a cone beam CT device at 0.2 mm nominal voxel resolution (i-CAT Platinum; Imaging Sciences International, Hatfield, PA). The data were exported as digital imaging and communications in medicine files and imported into Dolphin Imaging & Management Solutions, v. 11.5 (Patterson Dental Supply Inc., St Paul, MN), InVivoDental, v. 5.0 (Anatomage Inc., San Jose, CA) and Kodak Dental Imaging Software 3D module, v. 2.1.11 (Carestream Health Inc., Rochester, NY) software. Cross-sectional images in the acquisition (using Xoran CAT™, v. 3.0.34 software; Xoran Technologies, Ann Arbor, MI) and additional software were presented to three calibrated oral radiologists who rated the presence or absence of root fracture on a five-point scale. Receiver operating characteristic analysis was performed, and treatment comparisons compared by analysis of variance and pairwise comparisons were performed using Tukey's test at an a priori value of α < 0.05%.

RESULTS

All dental software performed equally at detecting fractures. Fractures were significantly more difficult to detect when posts were present.

CONCLUSIONS

The diagnosis of root fracture is software-independent. The presence of an intracanal metallic post significantly decreases the detection of artificially created root fractures.

Spiral computed tomographic evaluation and endodontic management of a maxillary canine with two canals

Aberrations in the root canal system can pose a considerable challenge to the endodontist during root canal treatment. These anatomical variations are more commonly seen in maxillary molars and mandibular teeth, but only a few cases have been reported with alteration in the internal canal anatomy of maxillary canine. The present report describes the diagnosis of bilateral occurrence of two root canals in maxillary canines with single root and the endodontic management of the right maxillary canine with the aid of spiral computed tomography (CT). The CT images revealed the presence of Vertucci's type-III canal configuration in the right maxillary canine. The same canal pattern was found in the contra-lateral canine, which was absolutely healthy; and also all the mandibular anterior teeth and first premolars showed bifid canal pattern.

Association between periapical lesions and maxillary sinus mucosal thickening: a retrospective cone-beam computed tomographic study

INTRODUCTION

Odontogenic infections are a common cause of maxillary sinusitis. This study aimed to evaluate the relationship between teeth with periapical lesions or periodontal disease and sinus mucosal thickening using cone-beam computed tomography (CBCT) imaging.

METHODS

CBCT scans of 243 patients (485 sinuses) were evaluated retrospectively for the presence of periapical lesions and/or periodontal disease in posterior maxillary teeth and associated sinus mucosal thickening. Thickening >2 mm was considered pathological and was categorized by degree (2-5 mm, 5-10 mm, and >10 mm) and type (flat or polypoid). Descriptive, bivariate, and multivariate statistical analyses were performed.

RESULTS

Mucosal thickening >2 mm was observed in 147 (60.5%) patients and 211 (44.6%) sinuses and was mostly of a "flat" type. Bivariate analysis revealed significant associations between mucosal thickening >2 mm and sex (males), age (>60 years), and teeth with periapical lesions and periodontal disease (P ≤ .027). Multivariate regression analysis identified only sex (males, odds ratio = 1.98, P = .004) and teeth with periapical lesions (odds ratio = 9.75, P < .001) to be associated with mucosal thickening >2 mm.

CONCLUSIONS

Sinus mucosal thickening is a common radiographic finding, which is more likely to be observed in males (2×) and in relation to teeth with periapical lesions (9.75×).

An ex vivo comparison of digital radiography and cone-beam and micro computed tomography in the detection of the number of canals in the mesiobuccal roots of maxillary molars

INTRODUCTION

The purpose of this study was to compare digital periapical and cone-beam computed tomography (CBCT) images to determine the number of canals in the mesiobuccal root of maxillary molars and to compare these counts with micro computed tomography (μCT), which was also used to determine canal configuration.

METHODS

Digital periapical (RVG 6100), CBCT (9000 3D), and μCT images (the reference standard) were obtained of 18 hemi-maxillas. With periapical and CBCT images, 2 endodontists independently counted the number of canals in each molar and repeated the counts 2 weeks later. Teeth were extracted and scanned with μCT, and 2 additional endodontists, by consensus, determined the number and configuration of canals. The Friedman test was used to test for differences.

RESULTS

In mesiobuccal roots, 2 canals were present in 100% of maxillary first molars (13 of 13) and 57% of second molars (8 of 14), and 69% (9 of 13) and 100% (8 of 8) of these exited as 2 or more foramina. There was no difference in canal counts for original and repeat reads by the 2 observers with periapical (P = .06) and with CBCT (P = .88) and no difference when CBCT counts were compared with μCT counts (P = .52); however, when periapical counts were compared with μCT counts, there was a significant difference (P = .04).

CONCLUSIONS

For cadaver maxillary molars, μCT canal counts were significantly different from digital periapical radiograph counts but not different from Carestream9000 3D CBCT counts.

In-depth morphological study of mesiobuccal root canal systems in maxillary first molars: review

A common failure in endodontic treatment of the permanent maxillary first molars is likely to be caused by an inability to locate, clean, and obturate the second mesiobuccal (MB) canals. Because of the importance of knowledge on these additional canals, there have been numerous studies which investigated the maxillary first molar MB root canal morphology using in vivo and laboratory methods. In this article, the protocols, advantages and disadvantages of various methodologies for in-depth study of maxillary first molar MB root canal morphology were discussed. Furthermore, newly identified configuration types for the establishment of new classification system were suggested based on two image reformatting techniques of micro-computed tomography, which can be useful as a further 'Gold Standard' method for in-depth morphological study of complex root canal systems.

A preliminary study to determine the diagnostic reference level using dose-area product for limited-area cone beam CT

OBJECTIVES

The aim of this study was to measure the dose-area product (DAP) of limited-area cone beam CT (CBCT) units used by dental offices, and to evaluate the rationale of the DAP with an aid of optically stimulated luminescence (OSL) dosemeter in measuring radiation dose.

METHOD

The DAPs of 21 CBCT units used in the dental offices of Tokyo and the surrounding areas from five different manufacturers were measured using OSL nanoDot dosemeter. An assembly of OSL dosemeters with an X-ray film was exposed by CBCT units at exposure parameters commonly used in each dental office. DAP values were then calculated as expressed in mGy cm(2).

RESULTS

DAP values ranged from 126.7 mGy cm(2) to 1476.9 mGy cm(2), depending on the units used.

CONCLUSION

OSL dosemeter coupled with film can be utilized for a large-scale study to measure DAP. The DAP values for individual CBCT units depend not only on the field of view, but also on the exposure parameters adapted by the dental offices.

The detection of periapical pathosis using digital periapical radiography and cone beam computed tomography - part 2: a 1-year post-treatment follow-up

AIM

Part 2 of this clinical study aims to compare the radiographic change in periapical status of individual roots determined using digital periapical radiographs versus cone beam computed tomography (CBCT) 1year after primary root canal treatment and to determine the radiological outcome of treatment for each tooth.

METHODOLOGY

Periapical radiographs and CBCT scans of 123 teeth in 99 patients assessed 1year after completion of primary root canal treatment by a single operator were compared with their respective pre-treatment (diagnostic) periapical radiographs and CBCT scans. The presence or absence as well as the increase or decrease in size of existing periapical radiolucency was assessed by a consensus panel consisting of two calibrated examiners. The panel viewed the images under standardized conditions. Paired comparison of the outcome diagnosis of individual roots and teeth was performed using generalized McNemar's or Stuart-Maxwell test of symmetry analysis.

RESULTS

The 'healed' rate (absence of periapical radiolucency) for all roots combined was 92.7% using periapical radiographs and 73.9% for CBCT (P<0.001). This rate increased to 97.2% and 89.4%, respectively, when the 'healing' group (reduced size of periapical radiolucency) was included (P<0.001). A statistically significant difference in outcome diagnosis of single roots was observed between DPA and CBCT in single-rooted teeth and the buccal or mesio-buccal roots of multi-rooted teeth (P<0.05). Analysis by tooth revealed that the 'healed' rate (absence of periapical radiolucency) was 87% using periapical radiographs and 62.5% using CBCT (P<0.001). This increased to 95.1% and 84.7%, respectively, when the 'healing' group (reduced size of periapical radiolucency) was included (P<0.002). Outcome diagnosis of teeth showed a statistically significant difference between systems (P<0.001). Reconstructed CBCT images revealed more failures (17.6%) in teeth with no pre-operative periapical radiolucencies compared with periapical radiographs (1.3%) (P=0.031). In teeth with existing pre-operative periapical radiolucencies, reconstructed CBCT images also showed more failures (13.9%) compared with periapical radiographs (10.4%).

CONCLUSION

Diagnosis using CBCT revealed a lower healed and healing rate for primary root canal treatment than periapical radiographs, particularly in roots of molars. There was a 14 times increase in failure rate when teeth with no pre-operative periapical radiolucencies were assessed with CBCT compared with periapical radiographs at 1year.

Lateral radiographic technique: an alternative approach for anterior teeth

AIM

To describe the lateral radiographic technique, its use and indication.

BACKGROUND

The clinician's difficulty in performing the correct diagnosis for some endodontic situations sometimes leads to a compromised treatment of some teeth. Considering this, an alternative radiographic technique for anterior teeth (lateral radiographic technique - LRT) may be used to help endodontic diagnosis.

TECHNIQUE

This technique use a periapical radiographic film or sensor that is placed vertically in the anterior portion of maxilla or mandible and with the beam passing perpendicular to the radiographic film its possible to evaluate the possibility of a fenestration on the buccal cortical bone plate; differentiate overextension and overfilling; indentify root fractures; confirm the presence and location of an instrument in the root canal system; and assess the treatment of root perforations.

CONCLUSION

LRT is an easy and cheap technique that can be used to help in anterior teeth diagnosis.

CLINICAL SIGNIFICANCE

Considering that LRT is easy to perform and available at low cost, it could be utilized more by clinicians in the dental office in order to quickly assist in diagnosis. As a complimentary radiographic examination for anterior teeth, it could become a useful supplement to aid the clinical practice.

Detection of Procedural Errors with Stainless Steel and NiTi Instruments by Undergraduate Students Using Conventional Radiograph and Cone Beam Computed Tomography

INTRODUCTION

This study investigated procedural errors made during root canal preparation using stainless steel and nickel-titanium (NiTi) instruments by undergraduate students, using two diagnostic imaging methods.

MATERIALS AND METHODS

Sixty human molars were divided into three groups (n=20; group 1: K-Flexofile, group 2: K3, and group 3: BioRace). The root canals were filled with gutta-percha and AH Plus. Periapical radiographs and cone beam computed tomography (CBCT) images were obtained to detect procedural errors made by undergraduate students during root canal preparation. Two examiners evaluated the presence or absence of fractured instruments, perforations and canal transportations. The agreement between observers was assessed using the kappa coefficient. The Kolmogorov-Smirnov, Fisher exact, ANOVA and Tukey tests were used for statistical analysis. The level of significance was set at 5%.

RESULTS

There were no significant differences in detecting procedural errors between two- and three-dimensional diagnostic imaging methods. There were no significant differences in procedural errors between stainless steel and NiTi instruments. Mean preparation time was recorded in minutes, and results were significantly different between the three groups. NiTi instruments had the lowest mean preparation time.

CONCLUSION

Both periapical radiographs and CBCT identified procedural errors, however, three-dimensional images offered more diagnostic resources. The frequency of procedural errors was low for any of the endodontic instruments despite being used by inexperienced operators.

Evaluate root and canal morphology of primary mandibular second molars in Chinese individuals by using cone-beam computed tomography

BACKGROUND/PURPOSE

More detailed knowledge of root and canal morphology is important in order to improve the success in the endodontics of primary teeth. The purpose of this study was to evaluate the root and canal morphology of primary mandibular second molars (PMSMs) in a Chinese population using cone-beam computed tomography (CBCT).

METHODS

CBCT images, which had been obtained previously in the West China Hospital of Stomatology at Sichuan University, Chengdu, China between May 2009 and December 2011, were screened retrospectively. Finally, 283 individuals-207 male and 76 female with a mean age of 7.2 years (range 3-10 years)-and 487 PMSMs with clear images of root and canal morphology were enrolled. The number of roots and morphology of canals were recorded. The patient's gender, and the symmetry and frequency of three roots in PMSMs were analyzed.

RESULTS

The majority of PMSMs had two (72.28%) or three roots (27.52%). The symmetrical incidence of three-root PMSMs in this Chinese population was 50.65%. There is no difference between genders in the prevalence of an extra root and the incidence of symmetry (p > 0.05). Of the individuals enrolled, 25.26% of PMSMs had three canals and 73.31% had four canals. The root canal systems of the PMSMs in the present study were categorized into seven variants.

CONCLUSION

This study indicated that three-rooted PMSMs occur frequently in the Chinese population. There was no difference between the two genders on incidence and symmetry. The majority of PMSMs have three to four canals and the diversity of the root canal variants should be considered when performing clinical procedures. CBCT is a good option for studying the root and canal morphology of primary teeth.

Pixel intensity and fractal dimension of periapical lesions visually indiscernible in radiographs

INTRODUCTION

The purpose of the study was to analyze pixel intensity (PI) and fractal dimension (FD) values in radiographs of chemically created but visually undetectable periapical lesions.

METHODS

Artificial lesions were created by applying 70% perchloric acid to the sockets of left and right first premolars in 12 cadaver mandibles. For preparation of relatively small lesions, the acid was applied for 30 and 60 minutes. Before and after each acid application, radiographs were taken (60 kVp, 7 mA, and 1.5 mm Al equivalent filtration for 0.12 second) with storage phosphor plates. An optical bench was used to standardize projection geometry. Image plates were scanned immediately after exposure, and the acquired images were saved uncompressed in TIF format. Six observers evaluated the images by using a 5-grade scale, and the images scored as "definitely absent" by all observers were used for the calculations of PI and FD. Box-counting FDs and differences in mean PI were computed for regions of interest at the apical areas of each premolar. Repeated-measures analysis of variance, Tukey test, and Pearson correlation coefficient test were used for statistical analysis.

RESULTS

A significant difference was found in FD values after both acid application periods (P < .05), whereas a difference in PI was detected only in images obtained after 60-minute acid application (P < .05). There was a negative correlation between FD and PI values (-0.754, P < .05).

CONCLUSIONS

Calculation of FD can be a tool for the early detection of periapical lesions given the presence of baseline radiographs.

Effect of root canal filling materials on dimensions of cone-beam computed tomography images

Objective

To evaluate the discrepancy of root canal filling (RCF) measurements obtained from original root specimens and cone-beam computed tomography (CBCT) images.

Material and Methods

Seventy-two human maxillary anterior teeth were prepared up to an ISO #50 K-File 1 mm short of the apical foramen. Thus, the teeth were randomly divided into 8 groups, according to the root canal filling material: Sealapex^®, Sealapex^®+gutta-percha points, Sealer 26^®, Sealer 26^®+gutta-percha points, AH PlusTM, AH PlusTM+gutta-percha points, Grossman Sealer, and Grossman Sealer+gutta-percha points. After root canal preparation and RCF, CBCT scans were acquired and the specimens were sectioned in axial, sagittal and coronal planes. The RCF measurements were obtained in different planes and thicknesses to determine the discrepancy between the original root specimens (using a digital caliper) and the CBCT images (using the scanner's proprietary software). One-way analysis of variance and Tukey tests were used for statistical analyses. The significance level was set at α=5%.

Results

Measurements of the different endodontic filling materials were 9% to 100% greater on the CBCT images than on the original root specimens. Greater RCF dimensions were found when only sealers were used, with statistically significant difference among the groups.

Conclusions

RCF dimensions were greater on CBCT images than on the original root specimens, especially when only sealer was used.

Occurrence of maxillary sinus abnormalities detected by cone beam CT in asymptomatic patients

Background

Although cone beam computed tomography (CBCT) images of the maxillofacial region allow the inspection of the entire volume of the maxillary sinus (MS), identifying anatomic variations and abnormalities in the image volume, this is frequently neglected by oral radiologists when interpreting images of areas at a distance from the dentoalveolar region, such as the full anatomical aspect of the MS. The aim of this study was to investigate maxillary sinus abnormalities in asymptomatic patients by using CBCT.

Methods

1113 CBCT were evaluated by two examiners and identification of abnormalities, the presence of periapical lesions and proximity to the lower sinus wall were recorded. Data were analyzed using descriptive statistics, chi-square tests and Kappa statistics.

Results

Abnormalities were diagnosed in 68.2% of cases (kappa = 0.83). There was a significant difference between genders (p < 0.001) and there was no difference in age groups. Mucosal thickening was the most prevalent abnormality (66%), followed by retention cysts (10.1%) and opacification (7.8%). No association was observed between the proximity of periapical lesions and the presence and type of inflammatory abnormalities (p = 0.124).

Conclusions

Abnormalities in maxillary sinus emphasizes how important it is for the dentomaxillofacial radiologist to undertake an interpretation of the whole volume of CBCT images.

Application of cone beam volumetric tomography in endodontics

In a 2008 article on cone beam volumetric tomography (CBVT) and dentoalveolar applications, Tyndall and Rathore wrote: 'It is in the area of endodontic applications that the literature has proved most fruitful to date.' This statement is even truer today than in 2008. A review of the literature has demonstrated that, in many cases, CBVT is more efficacious than traditional forms of 2-D imaging. Endodontic applications of CBVT include the diagnosis of periapical lesions due to pulpal inflammation, identification and localization of internal and external resorption, the detection of vertical root fractures, the visualization of accessory canals, and elucidation of the causes of non-healing endodontically treated teeth. Prior to 2008, most published articles on CBVT applications in endodontics were either case reports or in vitro studies. Since that time more well designed clinically related scholarly activity has been published. This article attempts to survey the field of CBVT applications in endodontics and provide the readers with an overview of what has been found. The authors hope that this knowledge will form a foundation for appropriate clinical decision making with specific reference to selection criteria for the endodontic applications of CBVT.

Prevalence of apical periodontitis detected in cone beam CT images of a Brazilian subpopulation

OBJECTIVES

The aim of this study was to determine the prevalence of apical periodontitis (AP) detected in cone beam CT (CBCT) images from a database.

METHODS

CBCT images of 300 Brazilian patients were assessed. AP images were measured in three dimensions. Age, gender, number and location of total teeth in each patient were considered. AP location was considered according to tooth groups. The extent of AP was determined by the largest diameter in any of the three dimensions. Percentages and the χ(2) test were used for statistical analysis.

RESULTS

AP was found in 51.4% of the patients and in 3.4% of the teeth. Higher prevalence of AP was found in 60- to 69-year-olds (73.1%) and in mandibular molars (5.9%) (p < 0.05). Inadequate endodontic treatment presented higher prevalence of AP (78.1%).

CONCLUSIONS

AP can be frequently found in CBCT examinations. The presence of AP has a significant association with patients' age, and tooth type and condition. CBCT databases are useful for cross-sectional studies about AP prevalence in a population.

Comparison of cone beam CT device and field of view for the detection of simulated periapical bone lesions

OBJECTIVE

We aimed to assess the diagnostic accuracy of different cone beam CTs (CBCTs) and the influence of field of view (FOV) in diagnosing simulated periapical lesions.

METHODS

6 formalin-fixed lateral mandibular specimens from pigs were used for creating 20 standardized periapical bone defects. 18 roots were selected for the control group. Three CBCT devices [Accuitomo 3D® (Morita, Kyoto, Japan), NewTom 3G (Quantitative Radiology, Verona, Italy) and Scanora® (Soredex, Tuusula, Finland)] and three FOVs (NewTom 3G® FOV 6, 9 and 12 inches) were used to scan the mandible. Five observers assessed the images, using a five-point probability scale for the presence of lesions. Specificity, sensitivity and areas under the receiver operating characteristic (ROC) curves were calculated.

RESULTS

Sensitivity ranged from 72% to 80%. Specificity ranged from 60% to 77%. A difference in scoring between Scanora and the other two devices existed only in the control group. ROC analysis for different FOVs showed a decreased sensitivity with an increasing FOV, but this difference was not significant.

CONCLUSION

the control group, there was a difference between the CBCT devices regarding their specificity. FOV size did not show any difference in diagnostic performance. In cases in which conventional radiographic methods in combination with clinical evaluation are not sufficient, CBCT may be the method of choice to assess periapical pathology. CBCT examinations should be complementary to a clinical examination and FOV adaptation can be utilized to keep the dose to the patient as low as possible.

Digital method for quantification of circumferential periodontal bone level using cone beam CT

OBJECTIVES

The objective of this study is to develop a new approach for radiographically measuring circumferential periodontal bone level using cone beam CT (CBCT) data. Accuracy and precision were assessed using direct probe measurements on a human skull as a reference.

MATERIALS AND METHODS

Digital quantification of circumferential periodontal bone levels was conducted considering bone level measurements, infrabony crater, and furcation detection. For this purpose, a human bony cadaver skull with a restoration free dentition was used, showing periodontal bony defects of teeth 15-17,25-27,35-37,45-47 (FDI classification). Image datasets were acquired using a Promax 3D CBCT device (Planmeca Oy, Helsinki, Finland) at 80 kV and 8 mA, 160 μm voxel size. Circumferential radiographic measurements between cemento-enamel junction and the alveolar crest for the mesial, central, and distal bone levels on the oral and vestibular sides of the examined teeth were carried out based on a prototype of specifically developed software. The measurements were performed by an expert panel of three independent, calibrated, and blinded observers. Manual probe measurements of the periodontal bone loss served as reference standard.

RESULTS

The adopted software allowed the quantification of periodontal bone loss at all examined teeth. Overall deviation between radiographic and manual measurements of the observers ranged between 0.36 and 0.69 mm; hereby, 83 % of all results were <0.5 mm. Comparing overall accuracy between the ten turns of radiological measurements, accuracy for all observers ranged from 0.29 to 0.46 mm. The present study design showed a 100 % detection of furcation involvement for radiographic evaluation.

CONCLUSIONS

The adoption of a special measurement procedure in terms of a 3D coordinate system, which is placed through and perpendicular to the long axis of the tooth, allows consistent measurement positions of the mesial, central, and distal bone levels both for the oral and vestibular sides of the alveolar crest. In this way, reliable and reproducible quantification of circumferential periodontal bone loss using CBCT data with standardized resolution of 160 μm can be performed in all three dimensions.

CLINICAL RELEVANCE

This new approach of radiographically assessing circumferential periodontal bone level using CBCT data shows a first promising attempt of accurate detection of periodontal bony defects. Yet, possible negative impact of further clinical parameters in terms of artifact occurrence will have to be furthermore carefully investigated.

Radiological diagnosis of periapical bone tissue lesions in endodontics: a systematic review

This systematic review evaluates the diagnostic accuracy of radiographic methods employed to indicate presence/absence and changes over time of periapical bone lesions. Also investigated were the leads radiographic images may give about the nature of the process and the condition of the pulp in nonendodontically treated teeth. Electronic literature search included the databases PubMed, Embase and CENTRAL from January 1950 to June 2011. All languages were accepted provided there was an abstract in English. The MeSH terms were 'Cone beam computed tomography (CBCT)', 'Radiography, panoramic', 'Periapical diseases', 'Dental pulp diseases', 'Sensitivity and specificity', 'receiver operating characteristics (ROC) curve', 'Cadaver', 'Endodontics' and 'Radiography dental'. Two reviewers independently assessed abstracts and full text articles. An article was read in full text if at least one of the two reviewers considered an abstract to be potentially relevant. Altogether, 181 articles were read in full text. The GRADE approach was used to assess the quality of evidence of each radiographic method based on studies of high or moderate quality. Twenty-six studies fulfilled criteria set for inclusion. None was of high quality; 11 were of moderate quality. There is insufficient evidence that the digital intraoral radiographic technique is diagnostically as accurate as the conventional film technique. The same applies to CBCT. No conclusions can be drawn regarding the accuracy of radiological examination in identifying various forms of periapical bone tissue changes or about the pulpal condition.

Comparison of cone-beam and conventional multislice computed tomography for image-guided dental implant planning

OBJECTIVES

To compare the accuracy of cone-beam CT (CBCT) and multislice CT (MSCT) with regard to its use in image-guided dental implant surgery in a prospective model based study.

MATERIAL AND METHODS

Ten photopolymer-acrylate mandibula models, each with four precise metal reference markers, were scanned with MSCT and CBCT. The six reference distances between the markers were measured by a three-axis milling machine first. The distances were then measured by (1) navigation with the Medtronic StealthStation® TREON™ image-guided surgery system, (2) with the Medtronic planning-tool and (3) on the PC with the Mimics® software. Mean values were calculated for all three methods for CBCT and MSCT and were compared for statistical significance.

RESULTS

Of all measurements, 83% of the arithmetic mean values were within the ±0.5 mm range (MSCT 88% and CBCT 78%) and 17% within the ±1.0 mm range (MSCT 12% and CBCT 22%). The absolute difference of the arithmetic mean values showed no statistically significant difference between MSCT and CBCT. The difference of the overall mean values to the reference was 0.43 mm for MSCT and 0.46 mm for CBCT.

CONCLUSIONS

The data of our study prove that the application of CBCT for the indicated purpose yielded good results comparable to those of MSCT. All three measuring methods were feasible and accuracy was statistically not different between the data acquired by MSCT and CBCT within the setting of this study.

A suggested technique for the application of the cone beam computed tomography periapical index

OBJECTIVES

Cone beam CT (CBCT) produces undistorted three-dimensional (3D) images of the maxillofacial region with a radiation dosage lower than conventional CT. The periapical index score (PAI) is commonly used to follow up the lesions in the bone using periapical radiographs. Recently, a new PAI based on CBCT was introduced (CBCT-PAI). The aim of this technical report is to present a modified reproducible method to assess the CBCT-PAI.

METHODS

CBCT was used to evaluate a periapical bone lesion observed in the area of tooth number 13 before treatment and 2 years after treatment. The modified CBCT-PAI was applied to both the examinations to measure the lesion. The dimensional analysis of the lesion was performed in each plane, assessing three fixed and reproducible dimensions: mesiodistal (M-D), buccolingual (B-L) and coronoapical (C-A). The images were evaluated by three mutually independent examiners. Data were collected and reported in a chart. The results were compared with each other and with the PAI score from the periapical radiographs.

RESULTS

The three observers reported the same measurements of the lesion for each plane. The CBCT-PAI follow-up showed a reduction of the size of the lesion (5D vs 4D) but also an increase in the erosion of the buccal cortical plate. The comparison of CBCT-PAI with classic PAI showed the first method to be more precise.

CONCLUSIONS

This technical report shows how the CBCT-PAI can be applied to the CBCT exam of a periapical lesion in a reproducible way.

Volumetric difference evaluation of registered three-dimensional pre-operative and post-operative CT dental data

OBJECTIVE

The purpose of this study is to propose a complete methodology for automatically registering three-dimensional (3D) pre-operative and post-operative CT scan dental volumes as well as to provide a toolset for quantifying and evaluating their volumetric differences.

METHODS

The proposed methodology was applied to cone beam CT (CBCT) data from 20 patients in order to assess the volume of augmented bone in the alveolar region. In each case, the pre-operative and post-operative data were registered using a 3D affine-based scheme. The performance of the 3D registration algorithm was evaluated by measuring the average distance between the edges of the registered sets. The differences between the registered sets were assessed through 3D subtraction radiography. The volume of the differences was finally evaluated by defining regions of interest in each slice of the subtracted 3D data and by combining all respective slices to model the desired volume of interest. The effectiveness of the algorithm was verified by applying it to several reference standard-shaped objects with known volumes.

RESULTS

Satisfactory alignment was achieved as a low average offset of 1.483 ± 1.558 mm was recorded between the edges of the registered sets. Moreover, the estimated volumes closely matched the volumes of the reference objects used for verification, as the recorded volume differences were less than 0.4 mm(3) in all cases.

CONCLUSION

The proposed method allows for automatic registration of 3D CBCT data sets and the volumetric assessment of their differences in particular areas of interest. The proposed approach provides accurate volumetric measurements in three dimensions, requiring minimal user interaction.

The association between complete absence of post-treatment periapical lesion and quality of root canal filling

AIM

The technical quality of a root canal treatment is clinically judged by the apical extension and homogeneity of the filling material imaged by periapical radiographs (PA). The aim of this experiment was to evaluate the association between the technical quality of the root canal filling and treatment outcome.

MATERIALS AND METHODS

In 234 teeth (268 roots) that underwent root-canal treatment, the quality of the root canal filling as well as the outcome of the treatment were assessed with both PA and cone-beam computed tomography (CBCT) 2 years after treatment. Satisfactory root filling on PA was defined as 0-2 mm within the radiographic apex without voids; on CBCT scans, the apical end of the canal replaced the radiographic apex. The outcome predictors were analyzed using multivariate logistic regression.

RESULTS

At recall, periapical radiolucent areas were absent in 198 (74%) roots on PA and 164 (61%) roots on CBCT scans. The presence of preoperative periapical radiolucency and the quality of root filling and coronal restoration were identified by both PA and CBCT as outcome predictors (p < 0.01). Complete absence of post-treatment periapical radiolucency was observed in CBCT scans in 81% and 49% of satisfactory and unsatisfactory root fillings, respectively, as compared to 87% and 61% revealed by PA.

CONCLUSION

Satisfactory root fillings were associated with a favorable outcome, confirmed by both PA and CBCT.

CLINICAL RELEVANCE

The outcome of root canal treatment is improved once the filling is 0-2 mm from the apex, and no voids could be detected. Technical skills and performance of root canal filling procedures should be emphasized, and suitable methods should be developed in order to achieve more compacted filling materials without voids and at the correct length.