Assessment of alveolar bone changes in response to minimally invasive periodontal surgery: A cone-beam computed tomographic evaluation.

Purpose: The aim of this study was to evaluate 3-dimensional cone-beam computed tomography (CBCT) images of alveolar bone changes in patients who underwent minimally invasive periodontal surgery-namely, the pinhole surgical technique (PST). Materials and Methods: Alveolar bone height was measured and compared on CBCT images of 254 teeth from 23 consecutive patients with Miller class I, II, or III recession who had undergone PST. No patient with active periodontal disease was selected for surgery. Two different methods were used to assess the alveolar bone changes postoperatively. In both methods, the distance between the apex of the tooth and the mid-buccal alveolar crestal bone on pre- and post-surgical CBCT studies was measured. Results: An average alveolar bone gain >0.5 mm following PST was identified using CBCT (P=0.05). None of the demographic variables, including sex, age, and time since surgery, had any significant effect on bone gain during follow-up, which ranged from 8 months to 3 years. Conclusion: PST appears to be a promising treatment modality for recession that results in stable clinical outcomes and may lead to some level of resolution on the bone level. More long-term studies must be done to evaluate the impact of this novel technique on bone remodeling and to assess sustained bone levels within a larger study population.

Comparative Evaluation of Artifacts Originated by Four Different Post Materials Using Different CBCT Settings.

The aim of this study was to evaluate whether cone beam computed tomography (CBCT) images in the presence of four different post materials, obtained from different kVps with varying resolutions and varying metal artifact reduction (MAR) algorithms, differed in artifact estimation, and to compare tooth regions in terms of artifact value. MATERIALS AND METHODS: Forty premolar teeth were used in this study. Root canals were treated, and teeth were randomly distributed into four subgroups (n = 10) for the preparation of post materials: titanium, gold (Nordin), quartz fiber (Bisco DT Light), and glass fiber (Rely X). The CBCT images were taken with two different kVps, three different metal artifact reduction (MAR) algorithm options, and two different resolutions. For each protocol, the effective dose was calculated according to the dose area production (DAP) value. The standard analysis of variance technique and the Tukey multiple comparison adjustment method were used to assess interactions among material types, kVp, MAR, and voxel settings. RESULTS: More artifacts were found in the middle third than in the cervical third (p < 0.05). The mean value of artifacts was highest for gold (Nordin), 90 kVp, no MAR, and 100 voxel size. Glass or quartz fiber posts at low resolution, with high MAR and 96 kVp, originated fewer artifacts. Moreover, the use of 90 and 96 kVp with 200 voxel size and high MAR provided the least amount of radiation. CONCLUSION: The best setting for radiographic follow-up of post materials on the Planmeca ProMax is 96 kVp with low resolution and high MAR; this setting produced one of the lowest effective doses. CLINICAL SIGNIFICANCE: This study estimated the best scanning protocol by lowering the effective dose to a minimum level according to the "as low as reasonably achievable" principle, as well as assessing the tooth region and the post material generating the fewest artifacts, in order to prevent image interpretation challenges such as false-positive and false-negative results stemming from the deterioration of the visibility of the root canal due to perforation, fractures, and voids in the root canal region.

Radiological Assessment of Prevalance and Quality of Periapical Status of Endodontic Treatments.

BACKGROUND The aim of this study was to determine the current prevalence and quality of endodontic treatments and investigate the relationship of various factors with posttreatment endodontic disease (PTED) in a Turkish subpopulation. MATERIAL AND METHODS The cone beam computed tomography (CBCT) images of 1069 patients (male, 50.9%; female, 49.1%; mean age, 45.32±13.50 years) were retrospectively analyzed. A total of 20 646 teeth were examined; 1604 had undergone root canal. Periapical status was assessed using a modified CBCT periapical index. The relationship between periapical status and quality of root canal fillings (RCFs) was analyzed statistically using the chi-square test. Multivariate logistic regression was performed to evaluate the effect of individual parameters by adjusting them for other variables. RESULTS A total of 7.8% of all teeth had RCF. The prevalence of poor filling (having at least 1 procedural error) was 54.1%; the prevalence of PTED was 56.8%. The prevalence of PTED was 44.3% in teeth with short RCF, 10.8% with overextended RCF, 35.7% with nonhomogeneous RCF, and 15.5% in teeth with untreated root canals. The rate of RCF teeth with procedural errors associated with PTED was 76.2%. There was no significant difference between sexes in apical periodontitis (P>0.05), which developed more frequently in teeth with procedural errors. CONCLUSIONS The overall prevalence of poor fillings (having at least 1 procedural error) among RCF teeth was high (54.1%) in this subpopulation. There is a substantial need to improve the technical quality of endodontic treatment.

Influence of Cone-Beam Computed Tomography Voxel Sizes in the Detection of Chemically Induced External Root Resorptions.

BACKGROUND External root resorption usually does not present a clinical sign or symptom, and, therefore, diagnosis is mainly based on radiographic examination. Many studies confirmed the advantage and accuracy of cone-beam computed tomography (CBCT) in evaluating root resorptions. We aimed to evaluate the diagnostic accuracy of CBCT images of chemically induced external root resorptions on extracted human teeth taken in different voxel sizes. MATERIAL AND METHODS In this in vitro study, 36 maxillary and 36 mandibular human incisor teeth, extracted owing to periodontal disease, were used. External resorption cavities were created on the buccal and proximal surfaces by using 10% hydrochloric acid with different application periods of 10, 30, and 60 min. Resorption cavities in different depths were induced to simulate different levels of external resorption. CBCT images were taken with Planmeca Promax 3D Max CBCT (Planmeca, Helsinki, Finland) in 4 different voxel sizes: 400, 200, 150, and 100 µm. RESULTS There was no statistically significant difference between interobserver and intraobserver reliability. Higher observer agreement was obtained for 100-µm and 150-µm voxel sizes. For detection of external root resorption defects, interobserver agreement was highest for the 100-µm voxel size and when defects were located on the proximal side of the samples. The highest k values were obtained for samples kept in hydrochloric acid for 60 min. CONCLUSIONS Chemically induced resorption cavities should be used for experimental studies to better imitate clinical conditions. CBCT requirement is still ambiguous for detection of external resorptions, and more experimental and clinical studies are needed.

CBCT image artefacts generated by implants located inside the field of view or in the exomass.

OBJECTIVES: To compare artefacts in cone-beam computed tomography (CBCT) arising from implants of different materials located either inside the field of view (FOV) or in the exomass, and to test different image-acquisition parameters to reduce them. METHODS: CBCT scans of a human mandible prepared with either a titanium, titanium-zirconium, or zirconia implant were acquired with the Planmeca ProMax utilizing FOV sizes of 8 × 5 cm and 4 × 5 cm, which placed the implant inside the FOV (8 × 5 cm) or in the exomass (4 × 5 cm). The scanning parameters considered three conditions of metal artefact reduction (MAR), disabled, low, and high, and 2 kVp levels (80 and 90). The standard deviation (SD) of grey values of regions of interest was obtained. The effects of implant material, implant position, MAR condition, kVp level, and their interactions were evaluated by Analysis of Variance (α = 5%). RESULTS: The zirconia implant produced the highest SD values (more heterogeneous grey values, corresponding to greater artefact expression), followed by titanium-zirconium, and titanium. In general, implants in the exomass produced images with higher SD values than implants inside the FOV. MAR was effective in decreasing SD values, especially from the zirconia implant, only when the implant was inside the FOV. Images with 80 kVp had higher SD values than those with 90 kVp, regardless of the other factors (p < 0.05). CONCLUSIONS: Implants in the exomass lead to greater artefact expression than when they are inside the FOV. Special attention should be paid to scanning parameters that reduce metal-related artefacts, such as MAR activation and increasing kVp. This is especially important with a zirconia implant inside the FOV.

Assessment of the efficiency of a pre- versus post-acquisition metal artifact reduction algorithm in the presence of 3 different dental implant materials using multiple CBCT settings: An in vitro study.

PURPOSE: The aim of this study was to assess artifacts generated in cone-beam computed tomography (CBCT) of 3 types of dental implants using 3 metal artifact reduction (MAR) algorithm conditions (pre-acquisition MAR, postacquisition MAR, and no MAR), and 2 peak kilovoltage (kVp) settings. MATERIALS AND METHODS: Titanium-zirconium, titanium, and zirconium alloy implants were placed in a dry mandible. CBCT images were acquired using 84 and 90 kVp and at normal resolution for all 3 MAR conditions. The images were analyzed using ImageJ software (National Institutes of Health, Bethesda, MD) to calculate the intensity of artifacts for each combination of material and settings. A 3-factor analysis of variance model with up to 3-way interactions was used to determine whether there was a statistically significant difference in the mean intensity of artifacts associated with each factor. RESULTS: The analysis of all 3 MAR conditions showed that using no MAR resulted in substantially more severe artifacts than either of the 2 MAR algorithms for the 3 implant materials; however, there were no significant differences between pre- and post-acquisition MAR. The 90 kVp setting generated less intense artifacts on average than the 84 kVp setting. The titanium-zirconium alloy generated significantly less intense artifacts than zirconium. Titanium generated artifacts at an intermediate level relative to the other 2 implant materials, but was not statistically significantly different from either. CONCLUSION: This in vitro study suggests that artifacts can be minimized by using a titanium-zirconium alloy at the 90 kVp setting, with either MAR setting.

Assessment of signal-to-noise ratio and contrast-to-noise ratio in 3 T magnetic resonance imaging in the presence of zirconium, titanium, and titanium-zirconium alloy implants.

OBJECTIVE: We quantitatively compared the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in T1 weighted imaging (WI) and T2 WI sequences in 3 Tesla (T) magnetic resonance imaging (MRI) using zirconium, titanium (grades 4 and 5), and titanium-zirconium alloy implants to evaluate the effect of implant type and imaging sequence. STUDY DESIGN: MRI was acquired using a 3 T magnet with a 16-channel head coil. Implants of each type were mounted in gel and scanned in axial, coronal, and sagittal planes using fast spin echo sequences in T1 WI (TR = 600, TE = 12 milliseconds) and T2 WI (TR = 3000, TE = 80 milliseconds) sequences. Data were transferred to Synapse 3-D software, and images were measured twice by an oral and maxillofacial radiologist blinded to the type of implants. RESULTS: Zirconium implants resulted in the lowest SNR and CNR values (P < .05). No significant differences were identified between titanium (grades 4 and 5) and titanium-zirconium implants. The T2 WI sequence had a significantly higher SNR and CNR than T1 WI. There was no difference in intraobserver agreement between T1 WI and T2 WI. CONCLUSIONS: CNR and SNR at 3 T MRI are dependent on implant type and imaging sequence. Titanium (grades 4 and 5) and titanium-zirconium implants and the T2 WI sequence produced higher SNR and CNR values.

Estimation of contrast-to-noise ratio in CT and CBCT images with varying scan settings in presence of different implant materials.

OBJECTIVES: To assess the contrast-to-noise ratio (CNR) of four different types of dental implant materials in CT and cone beam CT (CBCT) images with varying scan settings. METHODS: Four different types of implants: zirconium (Zr), titanium (Ti) Grade 4 and 5 and titanium-zirconium (Ti-ZrO2) alloy were placed in a 3% gelatin phantom in a cylindrical plastic container and scanned with two different CT machines (GE Medical systems and Toshiba Medical Systems) and one CBCT machine (I-CAT, Imaging Sciences International) with different voxel sizes of 0.2, 0.25, 0.3 and 0.4 mm. Images were analyzed using ImageJ software with the purpose of estimating the CNR. RESULTS: The CNR obtained from images acquired with CT was lower than the CBCT with all voxel sizes tested. 0.3 and 0.4 mm voxel sizes exhibited the highest CNR (p < 0.05) that gives the best image quality. Among the implant materials tested, titanium Grade 5 has the highest levels of CNR while Zirconium has the lowest (p < 0.05). CONCLUSIONS: The optimum protocol for radiographic follow-up in areas near implants on the I-CAT is low-resolution settings (0.3 and 0.4 mm voxel sizes) which gave the highest CNR thus image quality. In presence of Zr implants, an alternative imaging modality (i.e., MRI) may be considered to avoid low-quality images.

Evaluation of artifacts generated by titanium, zirconium, and titanium-zirconium alloy dental implants on MRI, CT, and CBCT images: A phantom study.

OBJECTIVE: The aim of this study was to assess artifacts generated by zirconium, titanium, and titanium-zirconium alloy implants on magnetic resonance imaging(MRI), computed tomography(CT), and cone beam computed tomography(CBCT) and to correlate the findings to the dose-area product and exposure factors on CT and CBCT. STUDY DESIGN: Three phantoms were built by embedding zirconium, titanium, and titanium-zirconium implants in ultrasound gel. MRI, CT, and CBCT images were acquired by using multiple sequences and settings. For MRI, "artifact" was described as the length of signal void beyond the limits of the implant. For CT and CBCT, "artifact" was calculated by subtracting the gray level of the darkest pixel from the level of the lightest pixel. RESULTS: On MRI, zirconium implants had minor distortion artifacts, whereas titanium and titanium-zirconium implants created extensive artifacts (P < .05). On CT and CBCT, artifacts were less prominent with titanium and titanium-zirconium implants compared with zirconium (P < .05). Titanium grade 5 implants with 0.3 and 0.4 mm3 voxels produced the least severe artifacts. CONCLUSIONS: MRI images were less affected by artifacts from zirconium implants, whereas CT and CBCT images showed less severe artifacts from titanium and titanium-zirconium alloy implants. CT generated greater artifacts compared with CBCT. Larger CBCT voxel sizes reduced the dose-area product and the severity of artifacts.

MRI for Dental Applications.

Imaging of hard and soft tissue of the oral cavity is important for dentistry. However, medical computed tomography, cone beam computed tomography (CBCT), nor MRI enables soft and hard tissue imaging simultaneously. Some MRI sequences were shown to provide fast soft and hard tissue imaging of hydrogen, which increased the interest in dental MRI. Recently, MRI allowed direct visualization of cancellous bone, intraoral mucosa, and dental pulp despite that cortical bone and dental roots are indirectly visualized. MRI seems to be adequate for many indications that CBCT is currently used for: implant treatment and inflammatory diseases of the tooth.

Ultrasound in Dentistry: Toward a Future of Radiation-Free Imaging.

Ultrasonography (US) is a noninvasive, nonionizing, inexpensive, and painless imaging tool proven to be a valuable diagnostic tool in soft tissue assessment that also shows promise for hard tissue evaluation in dentistry. US has been investigated for its capability to identify carious lesions, tooth fractures or cracks, periodontal bony defects, maxillofacial fractures, and more. It has been used as a diagnostic aid in temporomandibular disorders, implant dentistry, and to measure muscle and soft tissue thickness. Unfortunately, the use of US in dentistry is still in its infancy; however, relevant research is promising.

Correlation between the visibility of submandibular fossa and mandibular canal cortication on panoramic radiographs and submandibular fossa depth on CBCT

Background: To identify a correlation between the submandibular fossa (SF) visibility and mandibular canal (MC) cortication on panoramic image and the depth of SF measured on CBCT and also correlation between the depth of SF and vertical and horizontal location of MC on CBCT. Material and Methods: 500 CBCT scans and panoramic radiographs were evaluated. SF depth types were classified as type I (< 2mm); type II (2-3mm) and type III (> 3mm) on CBCT. Visibility of SF and the cortication of MC on panoramic radiographs were compared with the depth of SF on CBCT. Distances between MC and mandibular inferior, buccal and lingual cortices were measured. Results: No statistically significant correlation was found between radiolucent appearances of SF, cortication of MC, and depth of SF. The deepest part of the fossa was in the second molar area followed by third and first molars. Negative weak correlations were found between B-MC, L-MC distances and depth of SF. Conclusions: Visibility of SF and cortication of MC on panoramic radiographs did not correlate with the depth of SF. A marked radiolucent submandibular fossa on panoramic image does not undoubtedly indicate a deep fossa, which emphasizes the importance of 3-D imaging in implant planning (AU)

No disponible

The prominent proteins expressed in healthy gingiva: a pilot exploratory tissue proteomics study.

Gingiva is a unique tissue which protects the underlying periodontal tissues from consistent mechanical and bacterial aggressions. Molecular analysis of gingiva is likely to improve our understanding of the underlying biological processes at work. The aim of this preliminary exploratory study is to analyze the proteomic profile of healthy gingiva and to detect prominently expressed proteins. Gingival tissue samples were obtained from periodontally healthy individuals who underwent surgical crown lengthening procedure. After protein isolation, two dimensional gel electrophoresis (2DE) gels were prepared for each sample and only protein spots common to all gels were selected to eliminate the bias caused by the effect of individuals on proteomic profile. Following the 2DE; in-gel tryptic digestion and MALDI-TOF/TOF steps were performed for protein identifications. Forty-seven proteins were successfully identified. The identified proteins were classified based on their classes, molecular functions and involvements in biological processes and metabolic pathways. Among them, 14-3-3 protein sigma, Protein DJ-1, Alpha-enolase, Triosephosphate isomerase, Superoxide dismutase, Peroxiredoxin-1, Protein S100-A9, Galectin-7, Annexin A2/A4, Carbonic anhydrase 1 and chaperone proteins are worthy of attention. The proteomic profile of the gingiva reflected its highly dynamic characteristics. Despite complexity of the gingival tissue proteome, 2DE was an effective approach in studying the common protein expression profile of the gingiva. Considering the significance of gingiva in the formation of periodontal diseases, it is important to generate a detailed proteome map of gingival tissue to set up a bridge between molecular events and the disease formation. This study established an initial proteome map of the gingival tissue from healthy individuals.

Effectiveness of digital subtraction radiography in detecting artificially created osteophytes and erosions in the temporomandibular joint.

PURPOSE: Erosions and osteophytes are radiographic characteristics that are found in different stages of temporomandibular joint (TMJ) osteoarthritis. This study assessed the effectiveness of digital subtraction radiography (DSR) in diagnosing simulated osteophytes and erosions in the TMJ. MATERIALS AND METHODS: Five intact, dry human skulls were used to assess the effectiveness of DSR in detecting osteophytes. Four cortical bone chips of varying thicknesses (0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm) were placed at the medial, central, and lateral aspects of the condyle anterior surface. Two defects of varying depth (1.0 mm and 1.5 mm) were created on the lateral, central, and medial poles of the condyles of 2 skulls to simulate erosions. Panoramic images of the condyles were acquired before and after artificially creating the changes. Digital subtraction was performed with Emago dental image archiving software. Five observers familiar with the interpretation of TMJ radiographs evaluated the images. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic accuracy of the imaging methods. RESULTS: The area under the ROC curve (Az) value for the overall diagnostic accuracy of DSR in detecting osteophytic changes was 0.931. The Az value for the overall diagnostic accuracy of panoramic imaging was 0.695. The accuracy of DSR in detecting erosive changes was 0.854 and 0.696 for panoramic imaging. DSR was remarkably more accurate than panoramic imaging in detecting simulated osteophytic and erosive changes. CONCLUSION: The accuracy of panoramic imaging in detecting degenerative changes was significantly lower than the accuracy of DSR (P<.05). DSR improved the accuracy of detection using panoramic images.

Temporomandibular disorders and oral parafunction in children living with their parents and children living in institutional protective care: a comparative study.

AIM: This study aimed: (i) to identify and compare the prevalence of temporomandibular disorders (TMDs) and oral parafunctions among children living in child-protection institutions (CLCPI) with children living with their parents (CLWP); (ii) to determine whether or not there is an association between oral parafunctions and TMDs; and (iii) to examine the possible impact of stress on TMDs. STUDY DESIGN: The study was conducted on a total of 385 children who were divided into two groups: the CLCPI group (n = 184); and the CLWP group (control, n = 201). All children 8-18 years of age and living in protective-care facilities in Kocaeli, Turkey, were included in this study in the CLCPI group. The CLWP control group comprised children of the same age as those in the CLCPI group, but those in the CLWP group were living with their families and were randomly selected from one primary school, one elementary school and one high school in Kocaeli, Turkey. Each child in the study completed a questionnaire and underwent a clinical examination. RESULTS: The overall prevalence of TMDs and oral parafunctions were higher in the CLCPI group than in the CLWP group (P < 0.05). The vast majority of participants reported at least one parafunction (CLCPI, n = 97.3%; CLWP, n = 93%). Problems related to family or friends were higher in the CLCPI group, whereas problems related to school lessons were higher in the CLWP group (P < 0.05). In both groups, positive associations were found between signs and symptoms of TMDs, oral parafunctions and stressful life events. CONCLUSION: The prevalence of signs and symptoms of TMDs and oral parafunctions differed significantly between CLCPI and CLWP groups, with children of the CLCPI group found to be significantly more prone to TMDs and oral parafunctions than children of the CLWP group.

Correlation between spheno-occipital synchondrosis, dental age, chronological age and cervical vertebrae maturation in Turkish population: is there a link?

OBJECTIVE: To assess the correlation between third molar mineralization (TMM), spheno-occipital synchondrosis (SOS) fusion, chronologic age and cervical vertebrae maturation (CVM) for skeletal maturation. MATERIALS AND METHODS: Radiographs for 116 patients between 8 and 28 years were evaluated for age determination using mandibular TMM, SOS fusion and CVM. Spearman Correlation and Kappa test analyses were used to assess the relationship between variables and for intraobserver reliability. RESULTS: Strong correlation was found between chronological age and TMM for males (r = .802) and females (r = .842), very strong correlation was found between age and CVM for males (r = .812) and moderate for females (r = .449), it was strong between age and SOS fusion for males (r = .810) and females (r = .643). Correlation between TMM and SOS was found to be strong for males (r = .759) and moderate for females (r = .534), it was strong between TMM and CVM for males (r = .723) and weak for females (r = .371). Very strong correlation was found between CVM and SOS fusion for males (r = .851) and strong correlation for females (r = .618). CONCLUSION: Good correlation was found between the degrees of TMM, fusion of SOS and CVM in young Turkish population.

Contrast-to-noise ratio with different settings in a CBCT machine in presence of different root-end filling materials: an in vitro study.

OBJECTIVES: To compare the contrast-to-noise ratio (CNR) of multiple acquisition settings for four types of retrograde filling materials in CBCT images taken for endodontic surgery follow-up. METHODS: 20 maxillary central incisors were endodontically treated and obturated with 4 different root-end filling materials: amalgam, mineral trioxide aggregate, SuperEBA(™) (Harry J Bosworth Company, Skokie, IL) and Biodentine™ (Septodont, Saint-Maur-des-Faussés, France). Teeth were placed in a skull and scanned, one by one, with the Planmeca ProMax(®) 3D Max (Planmeca, Helsinki, Finland); at different voltages: 66, 76, 84 and 96 kVp; with low, normal and high resolution and high definition (HD); with and without metal artefact reduction (MAR). Images were analyzed using ImageJ software (National Institutes of Health, Bethesda, MD) to calculate the CNR. The dose-area product was registered, and the effective dose calculated. RESULTS: No statistically significant difference was noted between the four materials. 84 and 96 kVp with low resolution and the use of MAR-generated images that have statistically better CNR than 66 and 76 kVp with HD, normal and high resolutions and without MAR. The use of low resolution also generated the smallest value of effective dose. CONCLUSIONS: The best setting for radiographic follow-up in an endodontic surgery with retrograde filling on the Planmeca ProMax is 96 kVp with low resolution and high MAR; this setting produced one of the lowest effective doses.

Radiologic assessment of third molar tooth and spheno-occipital synchondrosis for age estimation: a multiple regression analysis study.

For forensic age estimation, radiographic assessment of third molar mineralization is important between 14 and 21 years which coincides with the legal age in most countries. The spheno-occipital synchondrosis (SOS) is an important growth site during development, and its use for age estimation is beneficial when combined with other markers. In this study, we aimed to develop a regression model to estimate and narrow the age range based on the radiologic assessment of third molar and SOS in a Turkish subpopulation. Panoramic radiographs and cone beam CT scans of 349 subjects (182 males, 167 females) with age between 8 and 25 were evaluated. Four-stage system was used to evaluate the fusion degree of SOS, and Demirjian's eight stages of development for calcification for third molars. The Pearson correlation indicated a strong positive relationship between age and third molar calcification for both sexes (r = 0.850 for females, r = 0.839 for males, P < 0.001) and also between age and SOS fusion for females (r = 0.814), but a moderate relationship was found for males (r = 0.599), P < 0.001). Based on the results obtained, an age determination formula using these scores was established.

Evaluation and Reduction of Artifacts Generated by 4 Different Root-end Filling Materials by Using Multiple Cone-beam Computed Tomography Imaging Settings.

INTRODUCTION: After endodontic surgery, radiographic assessment is the method of choice to monitor bone defect healing. Cone-beam computed tomography scans are useful to check and identify the reasons of failure of surgical intervention or confirm healing; however, the artifact generated by some root-end filling material might compromise this task. The objective of the study was to compare the amount of artifacts generated by 4 root-end filling materials and to test multiple exposure settings used with these materials, when the effective dose generated by each protocol was taken into consideration. METHODS: Twenty central incisors were endodontically treated with retrograde obturation by using amalgam, Biodentine, MTA, and Super-EBA (5 of each). They were placed in a skull with soft tissue simulation and scanned by using the Planmeca Promax Max with different kilovolt peaks (kVp): 66, 76, 84, and 96 with and without the use of metal artifact reduction (MAR) algorithm and with low, normal, and high resolution and high definition. The Dose Area Product was registered, and the effective dose was calculated. RESULTS: Amalgam generated the highest amount of artifacts, whereas MAR and low resolution created fewer artifacts than other settings. The artifacts were also reduced with 96 kVp. The effective dose calculated with low resolution was remarkably lower than other resolutions. CONCLUSIONS: When used as root-end filling material, Biodentine, MTA, and Super-EBA generated fewer artifacts than amalgam. The use of 96 kVp with MAR and low resolution also reduced artifacts on the image and at the same time generated the lowest effective dose.

Clinical and radiological aspects of rhinoliths: report of five cases.

Rhinoliths are calcified masses in the nasal cavity caused by the deposition of nasal, lacrimal, and inflammatory mineral salts by accretion around an endogenous or exogenous nidus. Rhinoliths can be seen as incidental findings on panoramic radiography, although they typically appear blurred due to remaining outside the focus. Therefore, rhinoliths may be difficult to recognize; this difficulty can lead to misdiagnosis. Computed tomography (CT)/cone beam CT (CBCT) scans are generally necessary to define the precise location and to make a differential diagnosis. This article describes radiologic features of five cases of rhinoliths that were detected incidentally on panoramic radiographs. CT or CBCT images were obtained before removing the rhinoliths.