Purpose
This study examined the radiopacity of contemporary luting cements using direct digital radiography under a range of exposure conditions.
Materials and Methods
Disc specimens (N = 80, n = 10 ...per group, ø5 mm × 1 mm) were prepared from 8 resin‐based luting cements (BisCem Clearfil SA Luting, Duolink, Maxcem Elite Multilink Speed, Panavia F 2.0, RelyX Unicem Clicker, V‐link). The specimens were radiographed using a charge‐coupled device sensor along with an 11‐step aluminum step wedge (1.5‐mm incremental steps) and 1‐mm‐thick tooth cut using five tube voltage/exposure time setups (60 kVp, 0.10/0.08 seconds; 70 kVp, 0.10/0.08/0.06 seconds) at 4 mA and 30 cm. The radiopacity of the specimens was compared with that of the aluminum step wedge and human enamel and dentin using NIH ImageJ software (available at http://rsb.info.nih.gov/ij/). A linear regression model for the aluminum step wedge was constructed, and the data were analyzed by ANOVA and Duncan post hoc test.
Results
Maxcem Elite (5.142 to 5.441) showed the highest radiopacity of all materials, followed in order by Multilink Speed (3.731 to 3.396) and V‐link (2.763 to 3.103). The radiopacity of Panavia F 2.0 (2.025 to 2.429), BisCem (1.825 to 2.218), Clearfil SA Luting (1.692 to 2.145), Duolink (1.707 to 1.993), and RelyX Unicem Clicker (1.586 to 1.979) were between enamel (2.117 to 2.330) and dentin (1.302 to 1.685). The radiopacity of 70 kVp conditions was higher than that of the 60 kVp conditions.
Conclusions
The radiopacities of the tested luting materials were greater than those of dentin or aluminum, satisfying the criteria of the International Organization for Standardization, and they differed significantly from each other in the exposure setups.
This study aimed to analyze the characteristics of carotid artery calcification (CAC) in stroke and nonstroke patients using computed tomography angiographic (CTA) and panoramic images.
This is a ...retrospective study on patients who acquired both CTA and panoramic images at the Neurology Department of Kyungpook National University Hospital, Daegu, South Korea, between 2011 and 2016. The patients were divided into stroke (
= 109) and nonstroke (
= 355) groups based on the final diagnosis. CAC was analyzed in each group based on its presence, shape, and severity using the Formula: see text
test. The differences in age and sex between the two groups were examined using a two-sample
-test. A measure of intraobserver reliability was obtained using Cohen's κ index.
CAC was more frequently observed in the stroke group than in the nonstroke group using both CTA (stroke group, 100%; nonstroke group, 23.1%) and panoramic (stroke group, 83.5%; nonstroke group, 16.6%) images. Although scattered CAC shape and mild severity occupied the largest portion in both groups, vessel-outlined CAC was more common in nonstroke patients than in stroke patients. In age and sex analyses, only females patients in their 70 s showed significant differences in CAC shape between the stroke and nonstroke groups.
On both CTA and panoramic images, although CAC is found more frequently in the stroke group, vessel-outlined-shaped CAC in the nonstorke group shows significant differences compared to other shapes.
Glomerular epithelial protein-1 (Glepp1), a R3 subtype family of receptor-type protein tyrosine phosphatases, plays important role in the activation of Src family kinases and regulates cellular ...processes such as cell proliferation, differentiation, and apoptosis. In this study, we firstly examined the functional evaluation of Glepp1 in tooth development and morphogenesis. The precise expression level and developmental function of Glepp1 were examined by RT-qPCR, in situ hybridization, and loss and gain of functional study using a range of in vitro organ cultivation methods. Expression of Glepp1 was detected in the developing tooth germs in cap and bell stage of tooth development. Knocking down Glepp1 at E13 for 2 days showed the altered expression levels of tooth development-related signaling molecules, including Bmps, Dspp, Fgf4, Lef1, and Shh. Moreover, transient knock down of Glepp1 revealed alterations in cellular physiology, examined by the localization patterns of Ki67 and E-cadherin. Similarly, knocking down of Glepp1 showed disrupted enamel rod and interrod formation in 3-week renal transplanted teeth. In addition, due to attrition of odontoblastic layers, the expression signals of Dspp and the localization of NESTIN were almost not detected after knock down of Glepp1; however, their expressions were increased after Glepp1 overexpression. Thus, our results suggested that Glepp1 plays modulating roles during odontogenesis by regulating the expression levels of signaling molecules and cellular events to achieve the proper structural formation of hard tissue matrices in mice molar development.
An osteoma may originate from cartilage or embryonal periosteum. It may occur externally or within the paranasal sinuses. In most cases, a paranasal osteoma is a solitary lesion and is located in a ...single sinus. A double osteoma with maxillary sinusitis is rare. A 54-year-old woman was referred for evaluation and treatment of a right maxillary sinus bony lesion. She complained of headache and foul smell after sneezing since 1 month ago. Panoramic radiography revealed two radiopaque masses in the right maxillary sinus. Cone beam computerized tomography images revealed radiopacities with partially corticated borders attached to the medial wall of the right maxillary sinus, near-complete radiopacification of the right maxillary sinus, and peripheral bony thickening due to chronic sinusitis. On histopathologic examination, the removed radiopaque masses were diagnosed as osteomas.
To investigate dentists' perceptions and attitudes regarding radiation safety in dental practices in Korea.
207 dentists participated in this study. An anonymous survey was conducted regarding the ...following areas: years of practice, characteristics of the radiography equipment, knowledge of diagnostic reference levels, prescription of dental radiographs, use of radiation protection procedures and participation in the radiation safety program. Data were evaluated according to frequency distribution; the χ test; and Fisher's exact test, which was used to investigate statistical significances (p < 0.05) between those with less than 10 years of experience in practice vs those with 10 years of experience or more.
Approximately 83% of the dentists who responded to our survey participated in the radiation safety program, but only 58% were satisfied with it. There were statistically significant differences in the installation of X-ray units, learning pathway of diagnostic reference levels, prescription of dental radiography for new adult patients, use of personnel radiation monitoring systems and participation in the radiation safety program between those with less than 10 years of experience in practice vs those with 10 years of experience or more (p < 0.05).
Dentists with less than 10 years of experience were less attentive to radiation protection procedures. Therefore, taking both the duration of experience of dentists and the installed X-ray equipment into consideration, continuous and efficient education for both dental workers and patients regarding radiation safety and protection is recommended.
The aim of this study was to evaluate in vitro and ex vivo roles of bortezomib, a proteasome inhibitor that binds to the active site of the 26S proteasome, in tertiary dentin formation.
We ...established pulpal access cavity preparation that was treated with or without bortezomib before direct pulp capping with a calcium hydroxide–based material. We also analyzed bone morphogenetic protein (Bmp)- and Wnt-related signaling molecules using quantitative real-time polymerase chain reaction.
In the short-term observation period, the bortezomib-treated pulp specimens showed the period-altered immunolocalization patterns of nestin, CD31, and myeloperoxidase, whereas the control specimens did not. The bortezomib-treated group showed a complete dentin bridge with very few irregular tubules after 42 days. The micro–computed tomographic images showed more apparent dentin bridge structures in the treated specimens than were in the controls. Quantitative real-time polymerase chain reaction analysis showed up-regulated Bmp and Wnt.
These findings revealed that treatment with 1 μmol/L bortezomib induced reparative dentin formation that facilitated the maintenance of the integrity of the remaining pulpal tissue via early vascularization and regulation of Bmp and Wnt signaling.
•Bortezomib facilitates reparative dentin formation through modulated vascularization and inflammatory response.•Molecular mechanisms underlying bortezomib treatment would be related with Bmp and Wnt signaling.•Pulpal access cavity preparation using a mice model system permits us to evaluate a range of drugs for their ability of reparative dentin formation.
Objective: To assess the usefulness of cone beam computed tomography (CBCT) for characterizing electrode insertion and evaluate the influence of electrode insertion status on post-cochlear ...implantation (CI) outcomes.
Design: Twenty-six ears with post-CI CBCT scans were included. The devices were MED-EL Flex28 (n = 21) and Nucleus slim straight (n = 5). The parameters including cochlear duct length (CDL), insertion depth angle (IDA), insertion length of electrode (IL), and cochlear coverage (CC) were analyzed and compared with aided pure-tone threshold (PTA) with implant in free field, and open-set sentence score.
Results: The mean CDL was 36.8 ± 1.4 mm. Electrode array was dislocated into scala tympani in two ears. The mean IL and IDA were 26.5 ± 1.9 mm and 541.4 ± 70.2°. The mean linear CC (IL/CDL, 0.73 ± 0.06) was larger than the mean angular CC (IDA/900, 0.60 ± 0.08). The CBCT parameters showed correlation one another. While the aided pure-tone threshold was correlated with IL and IDA, there were no significant correlations in the open-set sentence score. For the postlingually deaf patients with single electrode (Flex 28), the sentence score had no significant correlation and the aided PTA was positively correlated with IL (R = 0.517, p = .028).
Conclusions: This study validated the CBCT evaluating the electrode array position. The CBCT could be helpful for the preoperative selection of the optimal array and prediction of the CC.
The endoplasmic reticulum (ER) is a site where protein folding and posttranslational modifications occur, but when unfolded or misfolded proteins accumulate in the ER lumen, an unfolded protein ...response (UPR) occurs. A UPR activates ER-stress signalling genes, including inositol-requiring enzyme-1 (Ire1), activating transcription factor 6 (Atf6), and double-stranded RNA-activated protein kinase-like endoplasmic reticulum kinase (Perk), to maintain homeostasis. The involvement of ER stress molecules in metabolic disease and hard tissue matrix formation has been established; however, an understanding of the role of ER-stress signalling molecules in tooth development is lacking. The aims of this study are to define the stage-specific expression patterns of ER stress-related molecules and to elucidate their putative functions in the organogenesis of teeth. This study leverages knowledge of the tissue morphology and expression patterns of a range of signalling molecules during tooth development. RT-qPCR, in situ hybridization, and immunohistochemistry analyses were performed to determine the stage-specific expression patterns of ER-stress-related signalling molecules at important stages of tooth development. RT-qPCR analyses showed that Atf6 and Perk have similar expression levels during all stages of tooth development; however, the expression levels of Ire1 and its downstream target X-box binding protein (Xbp1) increased significantly from the cap to the secretory stage of tooth development. In situ hybridization results revealed that Atf6 and Xbp1 were expressed in cells that form the enamel knot at cap stage and ameloblasts and odontoblasts at secretory stage in stage-specific patterns. In addition, Atf6, Ire1, and Xbp1 expression exhibited distinct localization patterns in secretory odontoblasts and ameloblasts of PN0 molars. Overall, our results strongly suggest that ER-stress molecules are involved in tooth development in response to protein overload that occurs during signaling modulations from enamel knots at cap stage and extracellular matrix secretion at secretory stage.
The alveolar bone process is the thickened ridge of bone that bears the teeth and is known to have dynamic functional interactions with surrounding tissues. However, the detailed morphological ...changes that occur during alveolar bone process development and the underlying molecular mechanisms behind this morphogenesis have not been elucidated. In this study, we examined the detailed morphological changes of the alveolar bone process during mouse development using HE and MTC staining. In addition, we evaluated the precise localization pattern of various signaling molecules involved in blood vessel formation including CD31, α-SMA, VEGF, periostin, and TGF-β. Innervation of the alveolar bone process was examined following injection of the nerve terminal dye AM1-43. The morphological and immunohistochemical data suggested that there is an intimate relationship between alveolar bone process development and blood vessel formation. To more closely examine the role of blood vessels in alveolar bone process formation, we microinjected mice with a clinically available anti-VEGF antibody, bevacizumab, at PN5 and analyzed the effects 5 days later. Compared to the control animals, anti-VEGF treated animals showed a disruption of the integration of bony tissues to form the alveolar bone process structures, which should contain the periodontal ligaments. Based on these data, we conclude that specific morphogenesis of the alveolar bone process is closely associated with blood vessel formation.
A recently introduced direct drill-guiding implant surgery system features minimal tolerance of surgical instruments in the metal sleeve by using shank-modified drills and a sleeve-incorporated ...stereolithographic guide template. The purpose of this study was to evaluate the accuracy of this new guided surgery system in partially edentulous patients using geometric analyses.
For the study, 21 implants were placed in 11 consecutive patients using the direct drill-guiding implant surgery system. The stereolithographic surgical guide was fabricated using cone-beam computed tomography, digital scanning, computer-aided design and computer-assisted manufacturing, and additive manufacturing processes. After surgery, the positional and angular deviations between planned and placed implants were measured at the abutment level using implant-planning software. The Kruskal-Wallis test and Mann-Whitney U test were used to compare the deviations (α=.05).
The mean horizontal deviations were 0.593 mm (SD 0.238) mesiodistally and 0.691 mm (SD 0.344) buccolingually. The mean vertical deviation was 0.925 mm (SD 0.376) occlusogingivally. The vertical deviation was significantly larger than the horizontal deviation (P=.018). The mean angular deviation was 2.024 degrees (SD 0.942) mesiodistally and 2.390 degrees (SD 1.142) buccolingually.
The direct drill-guiding implant surgery system demonstrates high accuracy in placing implants. Use of the drill shank as the guiding component is an effective way for reducing tolerance.
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