CBCT-based volume of simulated root resorption - influence of FOV and voxel size

An evaluation of root resorption associated with the use of photobiomodulation during orthodontic treatment with clear aligners: a retrospective cohort pilot study

OBJECTIVES

To evaluate the change in tooth root volume using cone-beam computed tomography (CBCT) in a group of patients treated concurrently with clear aligners and an adjunctive photobiomodulation (PBM) device.

MATERIALS AND METHODS

This retrospective cohort pilot study included the records of 32 consecutively treated clear aligner patients (23 female, 9 male) from the private practice of one orthodontist. The PBM group (n = 16) used the device once per day for 5 minutes per arch and was compared with a matched control group (n = 16). A semiautomated segmentation technique was used to obtain tooth volume of anterior teeth from CBCT imaging prior to (T0) and during or immediately following (T1) orthodontic treatment with clear aligners. The change in root volume between time points was assessed.

RESULTS

There was no statistically significant difference between the pre- and posttreatment root volumes of maxillary and mandibular anterior teeth, regardless of which intervention group the patient belonged to (P > .05). There was also no difference in the mean percentage change in root volume between clear aligner patients in this study who were treated with the PBM device compared with a matched control group (P > .05).

CONCLUSIONS

Clear aligner patients in this study who changed their aligners every 3 to 5 days and used adjunctive photobiomodulation therapy did not experience clinically relevant orthodontically induced external root resorption. Due to the small sample size and measurement error in the root segmentation process, the results should be interpreted with caution.

Cone-beam computed tomography in endodontics: from the specific technical considerations of acquisition parameters and interpretation to advanced clinical applications

The implementation of imaging methods that enable sensitive and specific observation of anatomical structures has been a constant in the evolution of endodontic therapy. Cone-beam computed tomography (CBCT) enables 3-dimensional (3D) spatial anatomical navigation in the 3 volumetric planes (sagittal, coronal and axial) which translates into great accuracy for the identification of endodontic pathologies/conditions. CBCT interpretation consists of 2 main components: (i) the generation of specific tasks of the image and (ii) the subsequent interpretation report. A systematic and reproducible method to review CBCT scans can improve the accuracy of the interpretation process, translating into greater precision in terms of diagnosis and planning of endodontic clinical procedures. MEDLINE (PubMed), Web of Science, Google Scholar, Embase and Scopus were searched from inception to March 2023. This narrative review addresses the theoretical concepts, elements of interpretation and applications of the CBCT scan in endodontics. In addition, the contents and rationale for reporting 3D endodontic imaging are discussed.

The effect of optimum, indication-specific imaging fields on the radiation exposure from CBCT examinations of impacted maxillary canines and mandibular third molars

OBJECTIVE

Indication-specific optimum field-of-views (FOVs) have been assessed for CBCT scans of impacted maxillary canines and mandibular third molars, as 40∅ × 35 mm and 35∅ × 35 mm, respectively. The objective was to investigate possible changes in absorbed organs and effective doses, for these two imaging indications, performing CBCT examinations with optimum FOV sizes instead of commonly used FOVs. Additionally, radiation exposure-induced cancer risk was calculated for both imaging indications with optimum FOVs.

METHODS

An adult female head phantom (ATOM 702-D, CIRS, Norfolk, VA, USA) was scanned using Planmeca Viso G7 CBCT-device (Planmeca, Helsinki, Finland). Scanning factors, different FOV sizes, dose-area product (DAP) values and anatomical FOV locations were used for Monte Carlo PCXMC-simulation and ImpactMC software. In the PCXMC- simulation, 10-year-old child and 30-year-old adult phantoms were used to estimating effective and absorbed organ doses.

RESULTS

The effective dose varied from 58 µSv to 284 µSv for impacted maxillary canines, and from 38 µSv to 122 µSv for mandibular third molars, the lowest dose value for each corresponding to optimum FOV. Effective dose reduction between the optimum FOV and the smallest common FOV of 50∅ × 50 mm, maintaining other scanning factors constant, was 33% for impacted maxillary canines, and 45% for mandibular third molars. At all examinations, the highest absorbed organ doses were in salivary glands or in oral mucosa.

CONCLUSIONS

Optimum FOVs, 40∅ × 35 mm for impacted maxillary canine and 35∅ × 35 mm for mandibular third molar, could decrease effective doses received by young patients, and improve radiation safety in these common CBCT imaging procedures.

Present status and future directions: Imaging techniques for the detection of periapical lesions

Diagnosing and treating apical periodontitis (AP) in an attempt to preserve the natural dentition, and to prevent the direct and indirect systemic effects of this condition, is the major goal in endodontics. Considering that AP is frequently asymptomatic, and is most often associated with a lesion in the periapex of the affected tooth, within the maxillary bones, imaging becomes of paramount importance for the diagnosis of the disease. The aim of this narrative review was to investigate the most relevant classic and current literature to describe which are, to date, the diagnostic imaging systems most reliable and advanced to achieve the early and predictable detection of AP, the best measures of the lesions and the disclosure of the different features of the disease. Dental panoramic tomography (DPT) is a classic exam, considered still useful to provide the basic diagnosis of AP in certain districts of the maxillary bones. Periapical radiographs (PRs) represent a valid routine examination, with few, known limitations. Cone-beam computed tomography (CBCT) is the only system that ensures the early and predictable detection of all periapical lesions in the jaws, with the minor risk of false positives. These techniques can be successfully implemented, with ultrasounds (USI) or magnetic resonance (MRI) imaging, exams that do not use ionising radiations. MRI and USI provide information on specific features of the lesions, like the presence and amount of vascular supply, their content and their relationship with the surrounding soft tissues, leading to differential diagnoses. Further, all the three-dimensional systems (CBCT, USI and MRI) allow the volumetric assessment of AP. Pioneering research on artificial intelligence is slowly progressing in the detection of periapical radiolucencies on DPTs, PRs and CBCTs, however, with promising results. Finally, it is established that all imaging techniques have to be associated with a thorough clinical examination and a good degree of calibration of the operator.

Management of internal inflammatory root resorption using injectable platelet-rich fibrin revascularization technique: a clinical study with cone-beam computed tomography evaluation

OBJECTIVES

The current study evaluated clinically and radiographically the management of internal inflammatory root resorption (IIRR) in permanent anterior teeth with or without periapical lesions using injectable platelet-rich fibrin (i-PRF) regenerative approach.

METHODS

Ten systemically healthy patients, with thirteen anterior mature teeth diagnosed with IIRR were selected for the study. At the first visit, the tooth was anesthetized, access cavity opened, root canals were mechanically prepared then medicated with calcium hydroxide and temporarily sealed. After 2-4 weeks, regenerative endodontic procedures were performed by preparing and applying i-PRF inside the canal, then a freshly prepared PRF membrane was placed over it. White mineral trioxide aggregate was placed over the PRF matrix, and the tooth was restored with a glass ionomer cement base and resin composite restoration. The patients were recalled for clinical and radiographic evaluation and follow-up every 3 months for 12 months. Cone-beam computed tomography (CBCT) imaging was performed preoperatively and after 12 months.

RESULTS

Clinical evaluation results showed resolution of signs and symptoms through the follow-up period in all of the cases. Both CBCT imaging readings of IIRR lesions and periapical lesions revealed a volumetric significant difference (p = 0.00) between the preoperative and the 12-month follow-up period.

CONCLUSIONS

Usage of i-PRF could arrest and allow for healing of IIRR in permanent mature teeth and allow for periapical healing with successful clinical results.

CLINICAL RELEVANCE

i-PRF revascularization technique proved to be a successful REP in the treatment of the IIRR, reducing the number of appointments and increasing patient compliance.

Low-dose Multidetector Computed Tomographic and Cone-beam Computed Tomographic Protocols for Volumetric Measurement of Simulated Periapical Lesions

INTRODUCTION

The purpose of this study was to evaluate the accuracy of low-dose multidetector computed tomographic (LD-MDCT) imaging for the volumetric measurement of simulated periapical lesions.

METHODS

Eighteen monoradicular teeth were introduced in bone blocks, and periapical lesions were simulated at the periapical region of each tooth. All teeth were imaged using 4 acquisition protocols: large (dentoalveolar) field of view (FOV) cone-beam computed tomographic (CBCT) imaging (120 kV, 5 mA, and 0.2-mm voxel), small (dental) FOV CBCT imaging (90 kV, 10 mA, and 0.2-mm voxel), standard multidetector computed tomographic imaging (120 kV, 50 mA, and 0.62-mm voxel), and LD-MDCT imaging (120 kV, 10 mA, and 0.62-mm voxel). Tomographic images were evaluated by a single trained and calibrated examiner (intraclass correlation coefficient = 0.991) using ITK-SNAP segmentation software (University of Pennsylvania, Philadelphia, PA). The gold standard was obtained by the impressions of the lesions with regular fluid addition silicone and individual weighing using a precision analytical scale. Data were evaluated by the repeated measures analysis of variance test; the significance level was defined as P < .05.

RESULTS

No statistical differences (P > .05) were found among the groups regardless of the device, milliamperage, FOV, or voxel size.

CONCLUSIONS

LD-MDCT shows performance comparable with other standard reference methods for measuring the volume of periapical lesions and can be a useful and safe protocol in clinical situations in which CBCT imaging is not available, such as in cases of patients admitted to hospitals.

Effect of voxel size on detection of fenestration, dehiscence and furcation defects using cone-beam computed tomography

OBJECTIVES

This study aimed to assess the effect of voxel size on detection of fenestration, dehiscence, and furcation defects using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

This in vitro, experimental study evaluated 4 sheep skulls with both the maxilla and mandible accompanied by the surrounding soft tissue. Fenestration (n = 30), dehiscence (n = 65), and furcation defects (n = 46; 18 grade I, 25 grade II, and 3 grade III) were randomly created by round and needle burs in both jaws, and 40 areas served as control sites. CBCT scans were obtained with 0.300 and 0.150 mm³ voxel sizes and 8 × 11cm² field of view (FOV), and were randomly observed by four observers (two oral and maxillofacial radiologists and two periodontists). The kappa values, sensitivity and specificity were calculated for each voxel size and compared using paired t test.

RESULTS

By an increase in image resolution, diagnostic sensitivity increased while specificity decreased. The kappa values for fenestration (0.602-0.623), and grade III furcation defects (0.903-1.00) were optimal (> 0.6), and almost similar for both voxel sizes. The kappa values for dehiscence, and grades I and II furcation defects were unfavorable (< 0.6) and almost similar for both voxel sizes, except for grade I furcation defects, which had a significant difference in kappa values between the two voxel sizes (0.014 and 0.34).

CONCLUSION

Smaller voxel size had higher sensitivity and lower specificity for detection of all defects except for grade I furcation defects, for which the smaller voxel size had higher sensitivity and higher specificity.

Imaging diagnosis of external root resorption in replanted permanent teeth

The present study aimed to evaluate the performance of cone beam computed tomography (CBCT) and digital periapical radiographs (PR) in diagnosing external root resorption (ERR) in human permanent teeth replanted after traumatic avulsion. The samples comprised 39 permanent maxillary incisors replanted after traumatic avulsion. Digital PR and CBCT images were taken from each tooth and independently examined by 2 calibrated examiners to assess the ERR activity regarding type and extension. The degrees of agreement between both imaging examinations were determined by the mean global agreement index using SPSS software. The two imaging examinations diverged greatly in the diagnosis of the type of ERR since CBCT identified more cases as inflammatory ERR and PR as replacement ERR. A discordance level of 69.2% was observed between the two methods in the diagnosis of the type of ERR when CBCT for mesial and distal (MD) surfaces was considered and 61.5% when CBCT for mesial, distal, buccal and lingual (MD/BL) was considered. Likewise, CBCT and PR differed regarding the ERR index. PR examinations classified most cases as moderate or severe (69.2%), while CBCT examinations classified more cases as mild either in the MD surfaces analysis (41.4%) or in the analysis of the MD-BL surfaces (51.3%). In conclusion, the present results highlight a discrepancy between CBCT and digital PR performance in the diagnosis of different types and extent of ERR in replanted teeth.

Comparison of CBCT with different voxel sizes and intraoral scanner for detection of periodontal defects: an in vitro study

OBJECTIVES

This study aimed to compare the diagnostic accuracy of cone beam CT (CBCT) units with different voxel sizes with the digital intraoral scanning technique in terms of the detection of periodontal defects.

METHODS AND MATERIALS

The study material comprised of 12 dry skulls with maxilla and mandible. Artificial defects were created on teeth separately using burs randomly on dry skulls. In total 46 dehiscences, 10 fenestrations, 17 furcations, 12 wall defects and 13 without periodontal defect were used in the study. Each tooth with and without defects was imaged at various vertical angles using each of the following modalities: a Veraviewepocs 3D R100 CBCT device and a 3D Shape TRIOSㄾ Color P13 Shade Intraoral Scanner.

RESULTS

The κ values for interobserver agreement between observers ranged between 0.29 and 0.86 for the CBCT 10 × 8 cm field of view (FOV) with 0,160 mm3 voxel size; 0.35 and 1 for the CBCT 8 × 8 cm FOV with 0,125 mm3 voxel size; and 0.30 and 1 of intraoral scans. The κ values for detecting defects on anterior teeth were the least, following premolar and molar teeth both CBCT and intraoral scanning.

CONCLUSIONS

Smaller voxel sizes and smaller CBCT FOV has the highest sensitivity and diagnostic accuracy for detecting various periodontal defects among the scanner modalities examined.

ADVANCES IN KNOWLEDGE

Adequate evaluation of the condition of the alveolar bone and periodontal tissues is important for the diagnosis, treatment, and prognosis of periodontal disease. Limited examination methods, such as palpation, inspection, and periodontal probe examination, may provide insufficient information for the diagnosis of periodontal diseases.

Evaluating the effects of orthodontic materials, field of view, and artifact reduction mode on accuracy of CBCT-based caries detection

OBJECTIVES

To investigate the influence of orthodontic materials, field of view (FOV), and artifact reduction (AR) on the assessment of approximal caries using cone beam computed tomography.

MATERIALS AND METHODS

Forty non-cavitated and restoration-free human premolars and molars ranging from sound to various grades of lesions without cavitations were assigned to 13 groups with different combination of fix appliance equipment. CBCT (cone beam computed tomography) (Planmeca ProMax 3D Mid, Helsinki, Finland) images were obtained using combinations of three orthodontic bracket materials and two orthodontic archwire with small and large FOVs and with and without AR activation. Receiver operating characteristic (ROC) analysis was used to calculate the area under the ROC curve (AUC).

RESULTS

Interobserver agreement ranged from 0.44 to 0.92 and intraobserver agreement ranged from 0.50 to 0.99. Teeth lacking orthodontic materials had the highest Az values at 0.84. FOV and AR activation did not significantly affect AUC values (P > 0.05). The AUC data were significantly reduced by the addition of stainless steel wire, NT wire, or a combination of a stainless steel bracket with stainless steel wire (P < 0.05).

CONCLUSIONS

The addition of stainless steel wire, NT wire, or a stainless steel bracket with stainless steel wire combination prevented the diagnosis of non-cavitated interproximal tooth caries by CBCT. With and without AR modes and different FOVs did not influence the diagnosis of interproximal caries lesions with different types of orthodontic equipment.

CLINICAL RELEVANCE

A wide variety of brackets and wire combinations are used in the clinic; however, the extent to which these combinations impact the diagnosis of caries by CBCT as the effects of FOV and AR algorithms are unknown.

Age and sex estimation based on pulp cavity volume using cone beam computed tomography: development and validation of formulas in a Brazilian sample

OBJECTIVES

To develop and validate formulas for age and sex estimation based on the pulp cavity volume of teeth using cone beam CT.

METHODS

The sample was composed of 116 cone beam CT scans from Brazilian individuals of both sexes, ranging in age from 13 to 70 years. A total of 232 teeth (upper central incisors and canines) were evaluated. Two calibrated examiners determined pulp cavity volumes using the ITK-SNAP software. Pearson's correlation test was used to assess the correlation between chronological age and pulp volume. Linear and logistic regression models were developed for age and sex estimation, respectively, and were validated in another sample of 72 teeth.

RESULTS

Pearson's correlation coefficients between age and pulp volume were negative and significant (p < 0.0001) for both teeth (r = -0.8782 for central incisors and r = -0.8738 for canines). The age estimation formulas showed good determination coefficients (adjusted R² = 0.7614 to 0.8367). For sex estimation, when the age was known, the coefficients were also good (adjusted R² = 0.649 to 0.812). However, when the age was unknown, the coefficients of the sex estimation formulas were low (adjusted R² = 0.047 to 0.393). Validation showed high accuracy of age estimation in individuals older than 35 years, as well as high accuracy of sex estimation when the age was known.

CONCLUSIONS

Our formulas provided excellent results and can be applied to the Brazilian population. The best results were observed for age estimation in females and for sex estimation when the age was known.

Evaluation of Threshold Values for Root Canal Filling Voids in Micro-CT and Nano-CT Images

While several materials and techniques have been used to assess the quality of root canal fillings in micro-CT images, the lack of standardization in scanning protocols has produced conflicting results. Hence, the aim of this study was to determine a cutoff voxel size value for the assessment of root canal filling voids in micro-CT and nano-CT images. Twenty freshly extracted mandibular central incisors were used. Root canals were prepared with nickel titanium files to an ISO size 40/0.06 taper and then filled with a single cone (40/0.06 taper) and AH Plus sealer. The teeth were scanned with different voxel sizes with either micro-CT (5.2, 8.1, 11.2, and 16.73 μm) or nano-CT (1.5 and 5.0 μm) equipment. Images were reconstructed and analyzed with the NRecon and CTAn software. Void proportion and void volume were calculated for each tooth in the apical, middle, and coronal thirds of the root canal. Kruskal-Wallis and post hoc Mann-Whitney U tests were performed with a significance level of 5%. In micro-CT images, significantly different results were detected among the tested voxel sizes for void proportion and void volume, whereas no such differences were found in nano-CT images (p > 0.05). Micro-CT images showed higher void numbers over the entire root length, with statistically significant differences between the voxel size of 16.73 μm and the other sizes (p < 0.05). The values of the different nano-CT voxel sizes did not significantly differ from those of the micro-CT (5.2, 8.1, and 11.2 μm), except for the voxel size of 16.73 μm (p < 0.05). All tested voxel sizes enabled the detection of root canal filling voids except for the voxel size of 16.73 μm. Bearing in mind the limitations of this study, it seems that a voxel size of 11.2 μm can be used as a reliable cutoff value for the assessment of root canal filling voids in micro-CT imaging.

Accuracy of linear and volumetric measurements of artificial ERR cavities by using CBCT images obtained at 4 different voxel sizes and measured by using 4 different software: an ex vivo research

OBJECTIVES

To compare the accuracy of linear and volumetric measurements of artificial external root resorption (ERR) cavities by cone beam CT (CBCT) images obtained at four voxel sizes and by using four different software ex vivo.

METHODS

ERR cavities were created on 40 extracted single rooted anterior teeth. Images were obtained by using Planmeca CBCT unit at endo mode (0.075 mm); high-resolution mode (0.1 mm); high-definition mode (0.15 mm) and normal resolution mode (0.2 mm) voxel sizes. Images were analyzed by two observers using four different software (Romexis, 3D Doctor, ITK-SNAP, and OsiriX). (1) Diameter; (2) height; (3) depth; and (4) volume of the ERR were measured. CBCT measurements were then compared with direct physical measurements. ANOVA was used with general linear model analysis. The significance level was set at p < 0.05.

RESULTS

One-way ANOVA general linear model analysis showed no significant difference between or within observers for diameter, height, depth and volume measurements (p > 0.05). We found significant differences for diameter and volume measurements among softwares in terms of mean differences as compared to mean standard direct measurements (p < 0.05). We found statistically significant differences among voxel sizes and software for height measurements (p < 0.05). In addition, we found significant differences for diameter and volume measurements (p < 0.05) suggesting more accurate measurements for the cervical region when compared to apical region.

CONCLUSIONS

Observers using CBCT images obtained at four voxel sizes performed similarly in the quantification of artificial ERR with clinically insignificant distinction between CBCT softwares used.

Diagnostic accuracy of phosphor plate systems and conventional radiography in the detection of simulated internal root resorption

OBJECTIVE

To evaluate the performance of conventional radiography and photostimulable phosphor (PSP) plate in the detection of simulated internal root resorption (IRR) lesions in early stages.

MATERIALS AND METHODS

Twenty single-rooted teeth were X-rayed before and after having a simulated IRR early lesion. Three imaging systems were used: Kodak InSight dental film and two PSPs digital systems, Digora Optime and VistaScan. The digital images were displayed on a 20.1″ LCD monitor using the native software of each system, and the conventional radiographs were evaluated on a masked light box. Two radiologists were asked to indicate the presence or absence of IRR and, after two weeks, all images were re-evaluated. Cohen's kappa coefficient was calculated to assess intra- and interobserver agreement. The three imaging systems were compared using the Kruskal-Wallis test.

RESULTS

For interexaminer agreement, overall kappa values were 0.70, 0.65 and 0.70 for conventional film, Digora Optima and VistaScan, respectively. Both the conventional and digital radiography presented low sensitivity, specificity, accuracy, positive and negative predictive values with no significant difference between imaging systems (p = .0725).

CONCLUSIONS

The performance of conventional and PSP was similar in the detection of simulated IRR lesions in early stages with low accuracy.

Quantitative analysis of the relationship between maxillary incisors and the incisive canal by cone-beam computed tomography in an adult Japanese population

Background

In setting goals for orthodontic treatment, determining the morphologies of the alveolar bone and maxillary incisor root is important for avoiding root resorption, dehiscence, and fenestration. This study aimed to analyze the configurational relationships among maxillary incisors, the alveolar border, and the incisive canal by cone-beam computed tomography (CBCT).

Methods

Cone-beam CT images of 93 orthodontic patients were evaluated for length of the incisive canal (L); angles between the palatal plane and the maxillary alveolar border (θ1), the incisive canal (θ2), and maxillary incisor (θ3); distance from the left maxillary incisor to the incisive canal (D); and cross-sectional areas of the incisive canal (CSAs) at three vertical levels. Comparison of variables between male and female patients was performed with the two-sample t test. Correlations between parameters were examined by Pearson’s correlation analysis and Bonferroni correction for multiple comparisons.

Results

Male patients exhibited significantly greater values of L than female patients. There were significant positive correlations between θ1 and θ2, θ2 and θ3, and θ3 and θ1. While the value of D was the lowest at the oral opening, that of the cross-sectional area of the incisive canal (CSA) was the greatest at the incisal root apex.

Conclusions

This study demonstrated that the incisive canal had large inter-individual variability, and the proximity between the incisive canal and the incisal root could not be precisely predicted by the conventional cephalograms. Therefore, pre-treatment CBCT examination should be recommended when a large amount of maxillary anterior retraction and/or intrusion is planned in orthodontic diagnosis.

Efficacy of Different Cone-beam Computed Tomographic Protocols in the Identification of Mesiobuccal Canals of Maxillary First Molars: A Tomographic and Ex Vivo Study

INTRODUCTION

Complementary methods of anatomic diagnosis, including cone-beam computed tomographic (CBCT) imaging, may be useful in the diagnosis of mesiobuccal (MB) canals of maxillary molars.

METHODS

Thirty-five maxillary first molars were subjected to ex vivo analysis and 4 CBCT protocols: i-CAT Classic (Imaging Sciences International, Hatfield, PA) (ICC group), i-CAT Next Generation (Imaging Sciences International) (ICN group), PreXion 3D (PreXion, San Mateo, CA) (16.8-second acquisition time; PX1 group), and PreXion 3D (33.5-second acquisition time; PX2 group). The images were evaluated by 2 calibrated endodontists who kept records following protocols previously published in the literature. Micro-computed tomographic imaging was used as the control.

RESULTS

The correct identification of anatomic variations of MB roots was 54.3% (n = 19) in the ICC group, 65.7% (n = 23) in the ICN group, and 80.0% (n = 28) in the PX1 and PX2 groups. The probability of agreement between the ICC and the control groups was significantly different from the probability of agreement with the PX1 (P < .05) and PX2 (P < .05) groups. The other groups showed no significant differences compared with the control group. There was no difference in the probability of agreement between the tomographic protocols and the ex vivo results.

CONCLUSIONS

The PX1 and PX2 groups were more effective for the diagnosis of MB canals. PX1 is the most suitable because it results in a shorter radiation time and diagnostic imaging similar to PX2. The single-canal anatomy was the most prevalent in the study.

Interdisciplinary Approach for Management of Iatrogenic Internal Root Resorption: A Case Report

For management of a symptomatic maxillary lateral incisor with dull pain on chewing, suppurative sinus tract, defective metal-ceramic crown and iatrogenic internal root resorption, an interdisciplinary approach was taken. Two-visit nonsurgical treatment with calcium-enriched mixture (CEM) cement, replacement of metal-ceramic crown with all-ceramic crown and corrective periodontal plastic surgery were included in the treatment plan. Six-month and one-year follow-ups revealed complete resolution of signs and symptoms and radiographic healing. This case report highlights the importance of adequate cooling during crown preparation to preserve the pulp vitality and prevent internal resorptive lesions and also the profound sealing ability and biocompatibility of CEM cement.

Comparison of intraoral radiography and cone-beam computed tomography for the detection of periodontal defects: an in vitro study

Background

This study aimed to compare the diagnostic accuracy of cone-beam computed tomography (CBCT) unit with digital intraoral radiography technique for detecting periodontal defects.

Methods

The study material comprised 12 dry skulls with maxilla and mandible. Artificial defects (dehiscence, tunnel, and fenestration) were created on anterior, premolar and molar teeth separately using burs. In total 14 dehiscences, 13 fenestrations, eight tunnel and 16 without periodontal defect were used in the study. These were randomly created on dry skulls. Each teeth with and without defects were images at various vertical angles using each of the following modalities: a Planmeca Promax Cone Beam CT and a Digora photostimulable phosphor plates. Specificity and sensitivity for assessing periodontal defects by each radiographic technique were calculated. Chi-square statistics were used to evaluate differences between modalities. Kappa statistics assessed the agreement between observers. Results were considered significant at P < 0.05.

Results

The kappa values for inter-observer agreement between observers ranged between 0.78 and 0.96 for the CBCT, and 0.43 and 0.72 of intraoral images. The Kappa values for detecting defects on anterior teeth was the least, following premolar and molar teeth both CBCT and intraoral imaging.

Conclusions

CBCT has the highest sensitivity and diagnostic accuracy for detecting various periodontal defects among the radiographic modalities examined.

Comparison of the influence of FOV sizes and different voxel resolutions for the assessment of periodontal defects

OBJECTIVES

This study assessed the influence of different voxel resolutions of two different CBCT units on the in vitro detection of periodontal defects.

METHODS

The study used 12 dry skulls with a maxilla and a mandible. Artificial defects (dehiscence, tunnel, fenestration) were separately created on the anterior, premolar and molar teeth using burrs. A total of 14 dehiscences, 13 fenestrations, 8 tunnels and 16 non-defect controls were used in the study. Images were obtained from two different CBCT units in six voxel sizes (voxel size: 0.080, 0.100, 0.125, 0.150, 0.160 and 0.200 mm3). Kappa coefficients were calculated to assess both intra- and interobserver agreements for each image set.

RESULTS

Overall intraobserver kappa coefficients ranged between 0.978 and 0.973 for the 0.080-mm3 images and between 0.751 and 0.737 for the 0.160-mm3 images, suggesting notably high intraobserver agreement for detecting periodontal defects. CBCT performed significantly better at detecting fenestrations (p<0.05) than tunnel and dehiscence defects. No statistically significant difference was found between the detection of dehiscence and tunnel defects (p>0.05).

CONCLUSIONS

A voxel size of 0.150 mm3 was identified as the cut-off point for overall detection of periodontal defects. CBCT should be considered the most reliable imaging modality for the diagnosis of periodontal defects.