Cone-beam Computed Tomography Software Research Articles

Incidental Findings Following Dental Implant Procedures in the Mandible: A New Post-Processing CBCT Software Analysis.

Background/Objectives: The aim of this study was to evaluate incidental findings in the mandible after the placement of dental implants using a new cone-beam computed tomography (CBCT) software. Methods: The initial sample consisted of 2872 CBCT scans of patients of both sexes. The parameters evaluated in this study were the location of the implants in the mandible, implant length, anatomical relationship of the implant with the mandibular canal, presence or absence of damage to the adjacent teeth, presence or absence of implant fractures, and presence or absence of bone support. Fisher's exact test was performed to compare the variables. The significance level was set at p = 0.05. Results: Out of 2872 CBCT scans, 214 images of patients with an average age of 44.5 years were included. The most frequent location of the implants was the posterior region (93.5%), with 54% of the implants having a length between 9 and 14 mm. It was found that 92% of the implants were positioned above the mandibular canal. Damage to adjacent teeth was observed, with no correlation with the implant positioning (p = 1.000). In 100% of cases of implants in the anterior region, there was bone support. Fracture was observed in 1.7% of implants with a length between 9 and 14 mm. Conclusions: The installation of implants in the mandible occurs more frequently in the posterior region, with a high presence of bone support and a low incidence of damage to adjacent teeth, anatomical structures, and fractures.

Efficacy of the Sausage Technique in Rebuilding the Crestal Buccal Bone Thickness: A Retrospective Analysis.

The goal was to evaluate the efficacy of the sausage technique in reconstructing the crestal buccal bone thickness, focusing on the distribution shape of the regenerated volume. Ten implants were placed in five patients with Cawood-Howell class IV defects. A cone beam computed tomography (CBCT) was executed at T0 (before surgery). Guided bone regeneration (GBR) with the sausage technique utilized a resorbable collagen membrane, made of a 50% autologous bone and a 50% anorganic bovine bone matrix (ABBM) mixture. After 6 months, a CBCT (T1) was performed before implant placement. Using CBCT software, a plane parallel to the implant axis intersected perpendicular planes every 1.5 mm from the crest level. T0 and T1 CBCT sections were analyzed, yielding 140 measurements. Statistical analysis via SPSS revealed a significant increase in thickness (average 2.82 ± 1.79 mm). Maximum gains occurred at 4.5 mm from the coronal crest line (3.8 ± 1.51 mm). The GBR sausage technique was effective with minimal post-operative complications, yielding the biggest gain at the mid-ridge sagittal area. Within the analysis limitations, it can be assumed that the sausage technique is effective for horizontal GBR in the maxilla, but a lesser volume might be achieved at the crestal level because it seems to follow a bowed regeneration shape.

Three-Dimensional Measurement of Obturation Quality of Bioceramic Materials in Filling Artificial Internal Root Resorption Cavities Using Different Obturation Techniques: An In Vitro Comparative Study

IntroductionPathologic conditions such as internal root resorption (IRR) may complicate root canal filling. This study aimed to evaluate and compare the obturation quality by measuring the percentage of obturation volume (POV) in root canals with artificial IRR obturated with different materials and techniques using cone beam computed tomography (CBCT). MethodsForty single canal extracted mandibular premolars were decoronated to standardize their length to 14 mm. Following instrumentation, the roots were cut horizontally, and artificial IRR cavities were made at the level of 7 mm from the apex. The root halves were joined using cyanoacrylate adhesive. The samples were randomly assigned to 4 groups (n = 10), and the canals were filled as follows: single-cone technique (SC), bulk-fill Bio-C Sealer (BF), and Bio-C Repair for the coronal and middle third (BCR) + cold lateral condensation technique (CLC) for the apical third and continuous wave compaction technique (CWC). The pre- and postobturation volumes and the POV were measured in the total canal and for the apical, middle, and coronal thirds separately using CBCT and Mimics Medical software. The results were analyzed statistically using one-way ANOVA and Tukey HSD test, and statistical significance was set at P < .05. ResultsBF group resulted in significantly lower total, coronal, middle and apical POV values compared to SC, BCR + CLC, and CWC groups (P < .05), respectively. Also, at the apical third, the BCR + CLC group showed significantly lower POV than the SC and CWC groups (P < .05), respectively. The intra-group comparison showed that BF and BCR + CLC groups had a significantly lower POV in the apical third compared to the middle third (P < .05). Conversely, the CWC group had a significantly higher apical POV than the middle third (P < .05). ConclusionsThe maximum POV was obtained using the CWC technique, Bio-C Repair, and SC technique with Bio-C Sealer, making their application in IRR more preferable than the BF Bio-C Sealer.

Comparison of infrazygomatic crest bone screw position using a postero-anterior cephalogram versus cone-beam computed tomography: a cross sectional study

Abstract Background The position of infrazygomatic crest bone screws is an important consideration in determining the success of orthodontic treatment. The aim of this study was to compare the position of infrazygomatic crest (IZC) bone screws in relation to skeletal and dental parameters using postero-anterior (PA) cephalograms and cone beam computed tomography (CBCT). Methods A CBCT scan and a PA cephalogram were taken of 19 patients (8 males; 11 females) after IZC bone screw placement. Each CBCT image was reconstructed and oriented using the CS 3D CBCT software (Carestream Dental LLC, Atlanta, USA) and was subsequently analysed. The landmarks were traced on the PA cephalogram. The angulation of the IZC bone screw was measured with respect to three skeletal and two dental landmarks and compared between the two imaging modalities. A paired t-test was applied to compare the means of different variables between the PA cephalogram and CBCT scan. Results The results showed no statistically significant difference between the two imaging modalities with respect to four landmarks, i.e., the inter-jugale plane, the mid sagittal plane, the zygomatic arch and the perpendicular long axis to the 1st molar but a small statistically significant difference was seen with respect to measurements from the facial surface of the 1st molar (P ≤ 0.05). Conclusion The angulation and position of an IZC bone screw are consistent between the two imaging modalities. A PA cephalogram may be used as a substitute for a CBCT scan to reduce the radiation exposure to patients.

Accuracy of Cone-Beam Computed Tomography Software in Predicting the Size of Impacted Canine: A Preliminary Study.

To compare and analyze the precision, accuracy, and reliability of commonly used cone-beam computed tomography (CBCT) software in predicting the mesiodistal diameter of impacted canines. This study was conducted on 11 patients (six males and five females, mean age: 17.5±5.5 years) with either unilateral or bilateral impacted canines in the maxilla or mandible. DICOM data sets of the patients obtained from CBCT scans were then loaded and visualized with four selected CBCT software to measure the widest mesiodistal diameter of the impacted teeth. Physical measurements using a digital vernier caliper, kept as a control, were also made on the extracted teeth and orthodontically erupted teeth. The collected data underwent statistical analysis, and the statistical significance level was set at p<0.05. The Bland-Altman analysis was performed to quantify the agreement between different software to the digital caliper, showing a narrow difference for all plots. Kruskal-Wallis ANOVA test followed by a post hoc test was performed to determine whether there was any difference in measuring the mesiodistal diameter of the impacted canine among the five methods, and tend no statistically significant difference was found among the five methods. Intraclass correlation (ICC) was performed, and measurements made with all CBCT software yielded an ICC greater than 0.95, indicating high reliability of the selected software. All the evaluated CBCT imaging software exhibited a high degree of reliability, and accuracy in precise measurement of the mesiodistal diameter of an impacted tooth.

Evaluation of interorifice distance in permanent mandibular first molar with middle mesial canal in Bengaluru city, Karnataka: A cone-beam computed tomography study

Aim: Analysis of interorifice distance (IOD) between mesiobuccal and mesiolingual canals in the presence of middle mesial canal (MMC) variants in mandibular first permanent molar (MFPM) in an Indian subpopulation. To categorically assess the prevalence of MMC variants considering variation in factors of age and gender. Methods: Analysis of preoperative cone-beam computed tomography (CBCT) images was performed on 256 MFPM. MMCs were classified as fin, confluent, or independent as per the classification given by Pomeranz et al. (1981). Orthogonal slices from pulpal floor to 4 mm below were used to measure mean IOD using the CBCT software tool. Data were subjected to descriptive statistics. The Chi-square test was used for further analysis. Results: The prevalence of independent MMC was 4.7% (n = 12), confluent 14.6% (n = 37), and fin 8.7% (n = 22). The mean IOD measured for fin variant was 3.12 ± 0.512 mm, 3.31 ± 0.402 mm for confluence variant, 3.72 ± 0.493 mm for independent MMC, and 3.36 mm ± 0.579 for two-canal variant. Significant association (P = 0.001) was observed between age, gender, and overall detection of MMC, wherein the presence of fin (8.6%) and confluent (12.9%) configurations was higher (P = 0.003) in individuals ≤40 years. There was increased IOD in females (17.9%) than males (10.3%), for confluent, independent, and two-canal configuration (P = 0.04; =0.01, =0.001). Decreased IOD was observed in individuals >40 years for two-canal configurations (P = 0.05). Conclusion: Preoperative CBCT assessment of MFPM aids in the detection of MMC. According to the results of this study, individuals aged ≤40 years have shown higher prevalence of fin and confluent variants. Increased IOD was seen in females for confluent, independent, and two-canal configurations. Decreased IOD was seen in individuals aged >40 years having two-canal configuration. Thus, root canal complexities vary with age and gender, and should be taken into consideration before endodontic treatment.

An evaluation of cone beam computed tomography in verifying the level of collapse in obstructive sleep apnea patients

ABSTRACT Objective To assess the accuracy of cone beam computed tomography (CBCT) in verifying the level of collapse in obstructive sleep apnea (OSA) patients. Methods A prospective analysis of 30 patients with confirmed OSA was selected. Drug-induced sleep endoscopy (DISE) was performed for all cases to determine the level of collapse clinically. Two groups of patients were imaged with CBCT, one at end of expiration and the other at end of inspiration. Virtual endoscopy was performed on CBCT software. The level of collapse was recorded from both groups and compared to DISE findings. Results No statistical difference was discovered in the level of collapse observed from DISE or CBCT in most cases. Virtual endoscopy was found to have no role in determining collapse at tongue and lateral wall levels. Conclusion Using CBCT helped predict the air blockage level in patients with sleep apnea, which helps in surgical treatment planning measures.

Mandibular Teeth as Predictors in Forensic Age Estimation: A Cone-Beam Computed Tomography-Based Pulp Volume Regression Study.

Age estimation is integral to science of forensic odontology and plays an important role in human identification. Pulp volume estimation using cone-beam computed tomography (CBCT) to derive age can be very useful as it is noninvasive and can be applied on individuals of all ages. The study aimed to estimate the chronological age-based pulp and tooth volume (PTV) ratios in adults from Uttar Pradesh, India, using CBCT and voxel counting dental software. Thirty-six CBCT scans were allocated into three Groups, I, II, and III (12 in each group) randomly to study the pulp volume of lateral incisor, canine, and first premolar, respectively. PTV was calculated by image segmentation method using Xelis Dental software. A correlation between chronological age with PTV was established using derived regression equations. All the data were subjected to statistical analysis using Statistical Package for Social Sciences version 16.0. Estimated age and standard error were determined. Standard errors of estimates were 11.24 years (LI), 7.78 years (C), 9.89 years (PM) group, lowest being for canines. The estimated age was compared with the chronological age. The difference between the chronological age and the estimated age by the derived equation for the present study was statistically nonsignificant (P = 1.00). The results of the study show the feasibility of calculation of PTV ratios on CBCT to estimate the age for the set population with canine as the best predictor of age for the present study population.

Root canal length estimated by cone-beam computed tomography at different slice thicknesses, dedicated endodontic software, or measured by an electronic apex locator

The aim of the present study was to evaluate the agreements between the root canal length estimations using cone-beam computed tomography (CBCT) at different slice thicknesses, dedicated software, or an electronic apex locator (EAL) and the actual lengths (AL). In total, 111 extracted human molars with 302 root canals were chosen. Teeth were scanned using a CBCT device at a voxel size of 0.075 mm. Root canal lengths were estimated using CBCT software at different slice thicknesses (0.6, 1.2, and 2.4 mm) and dedicated software for proposed or operator lengths. The endodontic access cavities were created, and root canal lengths were estimated with an EAL for electronic length (EL) and a ruler for AL. Data were tested using paired t-tests and Bland–Altman plots to detect the differences between the methods in length estimation at a significance of 0.05. The accuracy in the range of ± 0.5 mm was 100% for the EAL. There was an agreement between the EL and CBCT at a slice thickness of 1.2 mm (p = 0.349). CBCT at the smallest slice thickness estimation was not the best modality in agreement with the AL. The EAL was an accurate and reliable method for root canal length measurement.

Evaluation in the danger zone of mandibular molars after root canal preparation using novel CBCT software.

This study measured the thickness of cementum/dentin in the danger zone of the mandibular molars after root canal preparation using novel cone-beam computed tomography (CBCT) software. Eighty-four teeth were distributed into four groups: ProTaper Next, BioRace, Reciproc Blue, and WaveOne Gold. E-Vol DX® CBCT software was used to measure initial and final remaining cementum-dentin thicknesses after root canal preparation of the mesial root of mandibular molars at 1 and 3 mm from the furcation. The Kolmogorov-Smirnov test was used to test variable symmetry. The variables were described as mean and standard deviations, compared among the groups using analysis of variance (ANOVA), and within the groups using the Student t test. A generalized estimating equation model was used to compare the variation before and after root canal preparation. The level of significance was set at 5%. Differences between mean initial and final thicknesses of the mesiobuccal (MB) and mesiolingual (ML) canals were not statistically significant. The mean initial thickness was 3 mm (0.900 mm ± 0.191), considering that a mean lower than 1 mm (1.035 mm ± 0.184) indicates the danger zone. Although cementum/dentin is thinner at 3 mm from the furcation (0.715±0.186) after root canal preparation, the greatest amount of dentin removed was found at 1 mm (0.734 ± 0.191). The cementum-dentin remaining after preparation was thicker than 0.715 mm in root canals prepared using #35 (WaveOne Gold®) and #40 (ProTaper Next®, BioRace® and Reciproc Blue®) instruments. This confirms the safety of canal preparation in the danger zone using these systems.

Comparison of mandibular buccal shelf bone characteristics between two facial types using cone beam computed tomography.

Mandibular buccal shelf (MBS) offers good quality and quantity of bone for orthodontic bone screw (OBS) insertion. Despite several reports of treated patients, there are numerous variables in selecting the exact placement site for OBS placement in the MBS. There are also anatomical variations in this area which must be considered. This study aims to measure and compare the MBS bone characteristics for OBS placement using cone beam computed tomography (CBCT) between two different facial types. Eighty CBCT samples were collected (40 samples of group A horizontal growers and 40 of group B vertical growers). Each CBCT image was reconstructed and oriented with CS 3D CBCT software. The cortical bone thickness, the slope of the MBS, and buccolingual inclination of mandibular second molar were measured and analysed. Cortical bone thickness among horizontal growers was 5.23 ± 0.58 mm and among vertical growers was 4.85 ± 0.37 mm. The slope of MBS among horizontal growers was 60.83 ± 6.15 degrees and among vertical growers was 66.75 ± 6.27 degrees. In both the parameters there was a statistically significant difference between the groups. There was no significant difference between the groups for the buccolingual inclination of 2nd molar. Increased cortical bone thickness and the flatter slope of MBS at the 2nd molar region allows for easier placement of OBS in horizontal growers than in vertical growers.

A single-center detection of adult patients with advanced periodontal disease using surgical assessment and cone-beam computed tomography

Context: One of the major limitations of conventional radiological procedures is the presence of considerable overlapping and lack of clear, three-dimensional information. Cone-beam computed tomography (CBCT) has emerged as an effective imaging modality in such situations offering high-quality images and lower radiation exposure to patients. Aim: The aim of the present study was to assess the role of CBCT in the detection of intra-bony defects in patients with advanced periodontal disease. Settings and Design: The present study was designed as a prospective, observational study wherein patients aged between 35–55 years with advanced periodontal disease who were indicated for periodontal treatment in form of periodontal surgeries were selected from the outpatient department (OPD) based on defined inclusion and exclusion criteria. Materials and Methods: Sixty patients with chronic periodontitis with 12 teeth each including 6 anterior and 6 posterior teeth were selected for making measurements pre- and peri-operatively while bone defects were measured first with the help of CBCT software installed in an individualized system devised to be used for storing and analyzing CBCT images and then, during surgical intervention using standardized UNC-15 periodontal probe and compared. Statistical Analysis Used: Statistical analysis was performed using SPSS version 18.0 (SPSS Inc., Chicago, IL, USA). The measurements obtained with the help of CBCT software installed in the personalized system and those obtained on surgical exploration were compared in each anterior and posterior tooth with the help of paired-sample t-test while Pearson's correlation(r) was used to test the correlation between the observed values. The level of statistical significance was set at P < 0.05. Results: The results were found to be highly significant both in terms of statistical (P-value) and clinical (r) significance for various sites in the anterior and posterior teeth in all instances. Conclusions: From the observations made from the present study, it could be concluded that CBCT provided highly precise assessment of bone topography equivalent to the judgment obtained during surgical exposure at the sites of interest preoperatively, which helped in assessing the exact type and depth of defect present and helped in optimizing surgical treatment planning.

Impact of cone-beam computed tomography with automated feeder detection software on the survival outcome of patients with hepatocellular carcinoma during treatment with conventional transarterial chemoembolization

BackgroundInoperable hepatocellular carcinoma (HCC) is treated by conventional transarterial chemoembolization (cTACE) using cone-beam computed tomography (CBCT) or digital subtraction angiography (DSA). We compared patient survival outcomes between CBCT-cTACE with automated tumor-feeder detection (AFD) software and DSA-cTACE alone in inoperable HCC patients.MethodsWe reviewed the data of 337 HCC patients treated by CBCT-cTACE or DSA-cTACE between January 2015 and December 2019. Treatment response, progression-free survival (PFS), overall survival (OS), and complications between the CBCT-cTACE and DSA-cTACE groups were compared. Univariate and multivariate logistic regression analyses examined the potential prognostic factors affecting survival after chemoembolization.ResultsTumor response rates in complete response, partial response, and stable disease at 1 month were 67%, 28%, and 4% in the CBCT-cTACE group and 22%, 48%, and 9% in the DSA-cTACE group, respectively. OS rates of patients in the CBCT-cTACE versus DSA-cTACE groups were 87% versus 54%, 44% versus 15%, and 34% versus 7% at 1, 3, and 5 years, respectively. The CBCT-cTACE group had significantly improved PFS (p < 0.001) and OS (p < 0.001). Multivariate analysis showed that CBCT with AFD software was an independent factor associated with longer OS (hazard ratio, 0.38; p < 0.001).ConclusionsCompared with conventional DSA, combining selective cTACE with CBCT and AFD software leads to better tumor response and prolongs OS in patients with inoperable HCC.

Method to Identify Accessory Root Canals using a New CBCT Software.

This study describes a methodology to identify accessory root canals using the e-Vol DX software in CBCT scans. Accessory root canals are strategic shelters for microorganisms present in root canal infections. The identification of these small canals in periapical radiographic exams has limitations, besides being markedly limited accessibility to the action of endodontic instruments and to the antimicrobial agents. A significant number of accessory canals have sufficient diameters to be visible on cone-beam computed tomography (CBCT) images of high spatial resolution. Therefore, it may go unnoticed or even confused when there is no specific training for this type of diagnosis. The methodology consists in establishing thin slices (0.1mm or smaller) obtained from coronal, sagittal and axial slices. The method consists of the following steps: during navigation along the long axis of a root canal when finding a possible hypodense line of main root canal in a tomographic section (axial, sagittal or coronal), the navigation software lines of the multiplanar reconstruction (MPR) must be adjusted so that they are parallel and perpendicular to the hypodense line (parallax correction). Then, after judiciously adjusted, the accessory canal image will invariably appear as a line on one of the MPR tomographic slices, another line on another slice, and a dot on the third slice. The three sections of the MPR present images with the "line-line-dot" sequence. In this way, it is possible to identify an accessory root canal and also visualize it in volumetric reconstruction in a specific filter. The application of this method is easy to employed and may benefit the diagnosis when you want to visualize accessory root canals and distinguish it from root fracture line.

BUCCAL BONE THICKNESS IN RETROMOLAR AREA IN RELATION TO BONE GRAFTING PRIOR TO DENTAL IMPLANTS. A CONE BEAM COMPUTED TOMOGRAPHY STUDY

Objective: To investigate the buccal bone thickness lateral to Inferior alveolar nerve at mandibular retromolar area using cone beam computed tomography (CBCT) scans. Materials and Methods: CBCT records of patients attending department of oral and maxillofacial surgery, University College of Dentistry, University College of Lahore from January 2018 till April 2020 were included in the present study. CBCT software was used to generate slices of 10mm in width starting from the cementoenamel junction (CEJ) on the distal side of the lower second molar in the panoramic view. The sagittal cross section at this point was used to measure the shortest distance from inferior alveolar nerve (IAN) to the outer cortical plate of mandible on both sides of mandible. t- test was used compare the mean bone thickness. Results: There was no significant difference in mean bone thickness between the right and left side of mandible in both the genders (P&gt;0.05). However, mean bone thickness varied significantly on right (P=0.012) and left side (P=0.019) of mandible between males and females. Conclusion: Retromolar area is a convenient source of autogenous bone as there is adequate thickness of bone in males and female however, care should be taken in females when retromolar area is chosen as a donor site. The role of CBCT in preoperative planning is crucial in determining the exact dimensions of the buccal bone thickness.

Longitudinal Study of Dental Implants in HIV-Positive Patients.

This study compared the clinical outcome of dental implants and their implant-supported restorations over a 3-year period involving patients both positive and negative for the human immunodeficiency virus. Twenty patients testing positive for the human immunodeficiency virus were recruited for this study. Twenty-one negative control patients were also selected, for a total of forty one patients. Diagnostic impressions were collected and cone beam computed tomography images were obtained. Implant size and positioning were planned using cone beam computed tomography software. Two stage or single surgery was performed as determined by the surgeon (periodontist). After a 6-month healing period, definitive impressions were fabricated using polyvinyl siloxane impression material. Implant stability quotient values were obtained at the time of surgery and placement of the restoration. Screw-retained custom titanium abutments were designed, milled, and placed with 25 N·cm torque using a calibrated torque controller. Porcelain fused-to-metal complete coverage restorations were then cemented with elastomeric resin implant cement. Implants and restorations were assessed at 6-month intervals over a period of 3 years for stability, peri-implant health, and patient satisfaction. Over the 3-year period, 25 of 42 implants placed in the negative control group were assessed, and 17 of 27 implants placed in the positive control group were evaluated. The overall patient retention rate was 77%. At the 3-year follow up, restorations examined were fully functional and causing no pain. Overall implant retention within the positive group was 96%. Implant retention within the negative control group was 100%. No differences were noted between groups for bone loss based on statistical tests. Within the limitations of this clinical investigation, the presence of human immunodeficiency virus per se was not a contraindication to dental treatment with implant-supported restorations.

A Critical Review of the Differential Diagnosis of Root Fracture Line in CBCT scans.

The objective of this critical review of literature is to discuss relevant clinical factors associated with root fractures (RF) visualized by using a new CBCT software. RF constitutes a common occurrence and a challenge in clinical practice, in which the diagnosis becomes essential for the definition of rapid and precise decision-making. The characterization of RF may involve different aspects, such as orientation of the fracture line (horizontal, vertical, oblique), root position of the fracture (cervical, middle, apical third), fracture's coronal-radicular position (coronary, coronal-radicular, radicular), continuity of the fracture (crack, incomplete fracture, complete), bone extension of the fracture (supraosseous, bone level, infraosseous fracture). Imaging examinations have been routinely used to aid in the RF diagnosis. Even with high-resolution cone-beam computed tomography (CBCT) scans, many doubts often remain about the diagnostic outcome. Many interferences in the analysis of image quality to determine the diagnosis are identified, such as the sharpness, the noise, light and dark artifacts, among others. The professional's knowledge is essential for identifying the different patterns of fracture lines and their repercussions on adjacent bone tissues, as well as for the analysis of artifacts that may hide or show similarities to fracture lines. Fractures lines and root fractures that may be associated with phantom conditions that mimic fractures should be carefully analyzed. CBCT is the exam indicated to identify a root fracture. It is also added to the success of the diagnosis that the professional has scientific knowledge, training and mastery of advanced CBCT software.

Blooming artifact reduction using different cone-beam computed tomography software to analyze endodontically treated teeth with intracanal posts.

The appearance of high-density root obturating materials, such as gutta-percha and intracanal posts, on cone-beam computed tomography (CBCT) scans is substantially different from that seen in the specimen. This study evaluated the effectiveness of different CBCT software in the reduction of blooming artifacts when examining teeth with intracanal posts. The sample included 42 human single-rooted teeth with two types of posts: G1 - low-fusion alloy posts; G2 - gold alloy posts. CBCT scans were obtained using two scanners, PreXion 3D Elite® and Carestream 9000C 3D®. First, the posts were measured using a digital micrometer (standard reference, control). Post diameters were determined using the Blooming Artifact Reduction (BAR) tool of the e-Vol DX software and of the PreXion3D Image Analysis System. Statistical data were evaluated using the van Der Waerden nonparametric analysis of variance and, after that, normalized data were analyzed using the Tukey test. The level of significance was set at α=5%. There were no significant differences (p>0.05) between the diameters of intracanal posts on the CT scans when the e-Vol DX was used, or when these results were compared with those obtained using a micrometer. There were significant differences in post diameters determined using the PreXion3D Image Analysis System when compared with the e-Vol DX and the micrometer values (p<0.05). The use of the e-Vol DX BAR filter eliminated blooming artifacts. There were no dimensional changes in the CBCT images of the low-fusion and gold alloy intracanal posts using the e-Vol DX BAR filter.

Implications of Virtual CBCT-Based Immediate Implant Planning for Maxillary and Mandibular First Molars.

The purpose of his study was to investigate the projected ridge-implant dimensions derived from virtual superimposition of implants on intact first molars mimicking immediate implantation in the mandible (Md1) and maxilla (Mx1) using cone-beam computed tomography (CBCT). The CBCT records of 41 patients (19 males and 22 females) with Md1 or Mx1 were collected. Ten-millimeter-long cylindrical implants with different diameters were virtually positioned at prosthetically ideal angles into interradicular septum using CBCT software. Radiographic alveolar ridge height (ARH), alveolar ridge width (ARW), gap distance, and vertical distance from the implant platform to the alveolar crest were measured. Twenty Mx1s (48.8%) and 21 Md1s (51.2%) were included. The mean ARH values were 7.13 ± 4.32 and 15.64 ± 1.80 mm for Mx1 and Md1, respectively; 87.8% of mesiobuccal sites had gap distance of >2 mm when 6-mm-diameter implants were used. Increasing implant diameter from 6 to 9 mm decreased the percentage of sites with ARW > 2 mm from 80.5% to 41.5% buccally and from 86.4% to 26.8% lingually. The mean vertical distance from the implant platform to the alveolar crest was 1.41 ± 1.09 mm buccally and 1.11 ± 1.10 mm lingually. Immediate implant placement of first molars, especially in the maxilla, requires stringent presurgical evaluation. Implants no wider than 6 mm placed into the interradicular septum may meet acceptable running room and alveolar plate thickness criteria if the jumping distance is grafted. Further clinical trials are needed to confirm these findings in this virtual study.

ACCURACY OF LINEAR MEASUREMENTS OF THIN CORTICAL BONE ON EXPERIMENTAL SURGICAL DEFECTS IN CBCT IMAGES WITH DIFFERENT EXPOSURE PROTOCOLS: AN IN VITRO STUDY

<h3>BACKGROUND</h3> Diagnostic imaging is mandatory for the assessment of osseous defects in the jaws. Traditional imaging has offered much over the decades in the evaluation of these defects but is limited because of its 2D nature. The introduction of cone beam computed tomography (CBCT), a 3D radiographic technique with interactivity, high resolution, and high accuracy, has provided solutions in the evaluation of such lesions <h3>OBJECTIVE(S)</h3> The purpose of this in vitro investigation was to evaluate the accuracy of representation of experimental surgical defects with CBCT using different exposure parameters. Moreover, the study aims to assess the effect of different exposure protocols on the accuracy of representation of experimental surgical defects. <h3>STUDY DESIGN</h3> Surgical defects were prepared in 8 pig jaw mandibular segments. The thickness of the cortical bone around the defects was measured in predetermined areas using the measurement tools of the CBCT software. In total, 48 locations were measured for bone thickness. The pig jaw specimens were imaged with 6 different exposure protocols created by altering voxel size, kilovoltage peak, and milliamperage. The measurements were made by 2 experienced examiners using the original scanner software. The evaluation of the surgical defects was completed in 4 rating sessions; a fifth rating session was included for intraobserver reliability assessment. <h3>RESULTS</h3> There were statistically significant differences in the estimation of cortical bone thickness around experimental surgical defects in certain sites among the variable exposure protocols; however, the differences were too small to be clinically important. The intra- and interobserver reliability values were very high, confirming the diagnostic value of CBCT in different exposure settings. <h3>DISCUSSION/CONCLUSIONS</h3> The accuracy of lineal cortical bone measurements with CBCT was high, even in lower dose protocols, a finding that is in line with the ALADA (as low as diagnostically acceptable) concept.