Dimensional Distortion of Four Types of Intracanal Posts on CBCT Scans with Different Fields of View and Resolutions

Objectives This study assessed the dimensional distortion of four types of intracanal posts on cone-beam computed tomography (CBCT) scans with two different fields of view (FOV) in high and standard resolution modes. Methods This in vitro study evaluated 40 extracted single-rooted maxillary central incisors that underwent root canal treatment. The teeth were randomly assigned to 4 groups (n=10) for placement of non-tapered brass, silver, titanium and stainless steel (SS) intracanal posts. The diameter of the posts was measured at two reference points by a digital caliper (gold standard). The teeth underwent CBCT with 8 x 8 and 8 x 12 cm FOV with high and standard resolution modes. The post diameters were measured on axial CBCT images at the same reference points and compared with the gold standard. Data were analyzed by ANOVA, and paired and independent sample t-test. Results Significant differences were noted between the radiographic diameter of the posts and their actual size (P<0.05). Titanium posts (40.25%) showed minimum percentage of dimensional distortion followed by brass (54%), silver (62.5%) and SS (70.17%) posts. High-resolution images with 8 x 8 cm FOV yielded minimum dimensional distortion (40.6%) followed by high-resolution images with 8 x 12 cm FOV (45.75%), standard-resolution images with 8 x 8 cm FOV (68.75%), and standard-resolution images with 8 x 12 cm FOV (72.1%). Conclusion All metal posts showed significant dimensional distortion on CBCT scans, irrespective of the FOV size and resolution mode. SS posts yielded maximum, and titanium posts showed minimum dimensional distortion

Prevalence of idiopathic osteosclerosis on cone beam computed tomography images

Objectives This study was performed to investigate the prevalence of idiopathic osteosclerosis on cone beam computed tomography (CBCT) images of patients.Methods In this descriptive, cross-sectional study, 240 CBCT scans of patients (125 women, 115 men) referred to a private oral and maxillofacial radiology clinic in Tehran in 2013 were selected and evaluated. Presence of idiopathic osteosclerosis and its features including its location in the jaw, its association with teeth, presence or absence of root resorption, number, shape and size of lesions and age and gender of patients were assessed. Descriptive statistics were reported. Chi-square test and independent t-test were used for statistical analysis.Results Idiopathic osteosclerosis was seen on CBCT images of 20 patients (8.33%). The lesion was more frequent in women than men, but the difference was not significant (P = 0.50). Also, the lesion was more common in the mandible than the maxilla (95.6% vs. 4.4%). Most lesions were observed in the molar (56.5%) and premolar (34.7%) areas of the lower jaw. Most lesions did not have any association with teeth (73.9%). More than half of the lesions (56.5%) were round in shape and the rest (43.4%) were irregular. The mean size of the lesions was 5.4 ± 1.8 and 5.7 ± 1.4 mm in the mesiodistal and superior-inferior aspects, respectively.Conclusion The prevalence of idiopathic osteosclerosis of the jaws on CBCT images of an Iranian population was within the range reported by other studies. The lesions were more common in the mandibular molar region with no relation to teeth

Diagnostic Accuracy of Cone Beam Computed Tomography in Identification of Foreign Bodies in the Head and Neck Region

Objectives This study aimed to assess the identification of traumatic foreign bodies in the head and neck region using cone-beam computed tomography (CBCT).Methods In this study, samples (1×1×0.1 cm) were fabricated from 6 different types of materials commonly found in various head and face traumas. These materials included iron, glass, stone, wood, asphalt, and tooth. They were located in 3 different areas, including the tongue, airway, and vestibule of 3 sheep heads. Ten scans were acquired from these materials embedded in different regions. A total of 180 images were analyzed by 2 observers and rated in terms of visual clarity of the foreign body. The results were analyzed by the Kruskal-Wallis test.Results In 100% of images, stone, asphalt, and glass were observed in all 3 areas with high resolution. On the other hand, 100% of images were unclear in all evaluated areas with metal artifacts. Tooth images were found to be excellent in 100% of cases in the muscle and airway regions and 80% of cases in the vestibule region (unclear in 20% of cases). However, wood was not detected in 100% of images from the tongue and vestibule regions. It was not detected on 60% of images from the airway, while it was found on 40% of images with low resolution.Conclusion CBCT detected and located all opaque objects such as iron, glass, stone, asphalt, and tooth. However, it showed limited potential in detecting radiolucent objects such as woo

Evaluation of Posterior Superior Alveolar Canal on Cone Beam Computed Tomography Images

Objectives The posterior superior alveolar artery (PSAA) is one of the branches of the maxillary artery that is located on the lateral wall of the maxillary sinus. The aim of the present study was to evaluate the detectability, position, and diameter of the posterior superior alveolar (PSA) canal and its relationship with the alveolar ridge using cone-beam computed tomography (CBCT).Methods A total of 257 CBCT images were evaluated. The PSA canal location was categorized into three forms of intra-osseous, below the membrane, and on the outer cortex of the lateral sinus wall. The distance between the lower border of the artery and the alveolar crest, the distance between the artery and the medial wall of the sinus, and the diameter of the artery were all measured. The prevalence of sinusitis and mucous retention cyst was also determined. The Chi-square test and independent t-test were used for statistical analysis.Results The most common type of PSA canal was intra-osseous, followed by beneath the mucosal membrane and on the outer cortex of the lateral sinus wall. The lowest distance between the PSA canal and medial sinus wall and ridge crest, and canal diameter were higher in males (P<0.05). In addition, sinus pathologies were significantly more common in males than females (P<0.05).Conclusion The most common type of PSA canal was intra-osseous, and the distances between the lower border of the canal and the alveolar crest and ridge height decreased with aging; thus, it should be considered during implant surgery

Effect of Amperage and Field of View on Detection of Vertical Root Fracture in Teeth with Intracanal Posts

Introduction: This study sought to assess the effects of amperage (mA) and field of view (FOV) on intracanal metal post artifacts and the diagnostic parameters for detection of vertical root fracture (VRF) in teeth with intracanal posts. Methods and Materials: In this diagnostic study, 80 human single-canal teeth were evaluated by cone-beam computed tomography (CBCT). Nickel chrome cast posts were placed into root canals after root canal therapy and canal preparation. In the test group, fracture was induced by an instron machine while no fracture was induced in the control group. Deterministic and probabilistic sensitivity and specificity values at different exposure settings were statistically analyzed using the one-way ANOVA and pairwise comparisons were performed by Tukey’s test. Results: Significant differences were found between the two groups in terms of deterministic (P<0.0001) and probabilistic (P<0.013) sensitivity and deterministic (P<0.037) and probabilistic (P<0.0001) specificity at different FOV and mA combinations. Conclusion: A smaller FOV and lower mA should be preferably used for detection of VRFs in teeth with intracanal posts.Keywords: Amperage; Cone-Beam Computed Tomography; Field of View; Metal Artifact; Vertical Root Fractur

Effect of Metal Artifacts on Detection of Vertical Root Fractures Using Two Cone Beam Computed Tomography Systems

Introduction: Vertical root fracture (VRF) is common in endodontically treated teeth. Conventional and digital radiographies have limitations for detection of VRFs. Cone-beam computed tomography (CBCT) offers greater detection accuracy of VRFs in comparison with conventional radiography. This study compared the effects of metal artifacts on detection of VRFs by using two CBCT systems. Methods and Materials: Eighty extracted premolars were selected and sectioned at the level of the cemento-enamel junction (CEJ). After preparation, root canals were filled with gutta-percha. Subsequently, two thirds of the root fillings were removed for post space preparation and a custom-made post was cemented into each canal. The teeth were randomly divided into two groups (n=40). In the test group, root fracture was created with Instron universal testing machine. The control teeth remained intact. CBCT scans of all teeth were obtained with either New Tom VGI or Soredex Scanora 3D. Three observers analyzed the images for detection of VRF. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for VRF detection and percentage of probable cases were calculated for each imaging system and compared using non-parametric tests considering the non-normal distribution of data. The inter-observer reproducibility was calculated using the weighted kappa coefficient. Results: There were no statistically significant differences in sensitivity, specificity, PPV and NPV between the two CBCT systems. Conclusion: The effect of metal artifacts on VRF detection was not significantly different between the two CBCT systems.Keywords: Cast Post; CBCT; Cone-Beam Computed Tomography; Vertical Root Fractur

Large Rhinolith Mimicking Atypical Odontogenic Pain: Case Report and Brief Review of the Literature

Rhinoliths are rare calcified entities in the nasal fossa, frequently originating around a nidus near the midway point in the inferior meatus, where the passage is the narrowest. They can be clinically asymptomatic and undetected for years. In this study, we present a rare case of large rhinolith mimicking atypical odontogenic pain in a 40-year-old Caucasian female in the left nasal cavity. The lesion was detected in the CBCT and removed uneventfully

A review on workflow and components in digital dentistry

Background and Aims: In recent years, the dentistry workflow has developed considerably. By the introduction of computers and their various applications, the effectiveness and efficiency of treatment has increased enormously. Considering engineering concepts in the workflow, it is necessary for participants to assess different steps and data transferring between various software and hardware devices. This research investigated the interaction between dentists, laboratories and production centers through the required steps for accomplishing treatment by different applications of software and digital hardware devices. Materials and Methods: Review in this article was based on searching Google scholar database considering key words: digital dentistry, workflow, computer aided design and manufacturing, dental CAD/CAM. This search was limited to the English articles published after the year 2000. Conclusion: It is necessary in dentistry to use digital technologies to improve the efficiency of treatments. Thus, the participants in this field must have appropriate knowledge to choose and apply these tools. Moreover, the participant should help providers of digital solutions for better development of software packages and related hardwares.

Digital workflow of producing dental implant surgical guide

Background and Aims: One of the important fields of dentistry is surgery for dental implants. In this field, dentistry has developed considerably in recent years amongst other fields of medicine from the perspective of digital device and software application. Surgical guides help dental surgeon for more precise, confident, easier and shorter surgery. Process of producing these tools are full digital and to somehow complex due to the application of many technical devices, software and protocols. To achieve efficiency, all participants in the workflow must be aware of all steps and data requirements for production of guides. This paper investigates the production process of surgical guide comprehensively, and also, encompass all the steps in process with details. Materials and Methods: This review article was based on searching Google scholar and PupMed databases considering key words: Surgical Guide, Guided surgery, digital dentistry, dental CAD/CAM, Additive manufacturing. More than 90% of the references were in English language and published after year 2010. Conclusion: Today dentistry uses many digital solutions for dairy workflow and most of these solutions are developed by engineers in various fields of knowledge. Thus, this information is essential for dentists, surgeon, clinician and laboratory technician, etc. for better collaboration and participation. Amongst, advances in surgery of dental implant have been highly significant and patients benefit from better treatment and less inconvenience. In addition, dentists do surgery more precise and easier because of considering all conditions before of surgery. Thus, it is substantial inform of all steps of production process