0000000000345174
AUTHOR
R Schulze
Cytotoxicity of Root Canal Filling Materials to Three Different Human Cell Lines
The aim of this study was to investigate the biological compatibility of five root canal sealers (Sealapex, Endion, Super-EBA, Ketac-Endo, and AH Plus) and regular and calcium hydroxide-based gutta-percha in three different human cell lines. Cultures without root canal sealers were used as controls. Cell growth, cell morphology, cell viability, protein content of the cells, and prostaglandin E 2 (PGE 2 ) release were used as parameters to determine the cytotoxicity of the materials. The protein content of the three cell lines—nasal fibroblasts, gingival fibroblasts, and epithelial tumor cells—was significantly reduced (p ≤ 0.001) by all materials tested. Determinations of PGE 2 release show…
The Treatment of Anterior Dental Trauma
Anterior dental trauma is a common injury pattern of the dentoalveolar system in which appropriate first aid is important. When children and adolescents suffer an anterior dental trauma, the challenge is to preserve the tooth in this esthetically important area and minimize subsequent damage. Lack of treatment or improper treatment can lead to a lifelong need for dental care. There are many causes of anterior dental trauma. At the age of one and two years, it is mainly caused by falls when learning to walk. At preschool age, between two and six years, many such injuries are caused by falls resulting from lack of attention when engaging in physical play. The highest incidence of anterior den…
The Image Gently in Dentistry campaign: promotion of responsible use of maxillofacial radiology in dentistry for children
© 2014 Published by Elsevier Inc. The Image Gently in Dentistry campaign to be launched in September 2014 is a specific initiative of the Alliance for Radiation Safety in Pediatric Imaging, supported by organized dentistry and dental education as well as many dental specialty organizations. The objective of the campaign is to change practice by increasing awareness of the opportunities to improve radiation protection when imaging children in dental practices. Six practical steps are provided that underline the principle that one size does not fit all, especially when it comes to using radiography during pediatric dental procedures. When we image children, let us image gently: More is often …
Length of endodontic files measured in digital radiographs with and without noise-suppression filters: an ex-vivo study
The aim of this study is to evaluate if theoretically possible edge shifts induced by noise-suppression filters potentially occur on objects found in digital radiographs. Most manufacturers carry out noise-suppression filtering of their images before they are displayed to the user. It is not usually possible for the user to disrupt the function of the filters. The use of these filters can lead to deletion of small image structures.K-files (ISO size 06, 08, 10 and 15) were placed in the root canals of 6 human teeth located in cadaver jaw segments. File tip positions were measured on original and filtered digital images by three observers. The file position was marked on each filtered image a…
Landmark identification on direct digital versus film-based cephalometric radiographs: A human skull study
The purpose of this study was to investigate differences in landmark identification on vertically scanned, direct digital and conventional (18 x 24 cm) cephalometric radiographs. Eight observers, all orthodontists or postgraduate orthodontic students, recorded 6 landmarks twice on 3 digital and 3 conventional cephalograms obtained from 3 human skulls in a standardized fashion. Digital images were displayed on a 15.1-in TFT monitor in 3:1 mode (20 x 26 cm). Recordings were transferred into standardized coordinate systems and evaluated separately for each coordinate. After correcting for magnification, precision was assessed with Maloney-Rastogi tests, and intraobserver and interobserver repr…
On cone-beam computed tomography artifacts induced by titanium implants
Objectives: To briefly review the mathematical background of beam-hardening artifacts in cone-beam computed tomography (CBCT)-reconstruction and to investigate geometrical properties relevant for these reconstruction errors. By means of simulated and experimental results, beam-hardening effects caused by titanium implants are evaluated. Materials and methods: The geometrical and physical properties of the acquisition process of the projections used for 3D reconstruction are investigated and their effects on the CBCT images in the presence of titanium implants are derived. Beam-hardening effects are computed for a simplified polychromatic situation (three energy subsets of 80 and 110 kV) and…
Dental CBCT equipment and performance issues
Dental cone beam computed tomography (CBCT), also known as digital volumetric tomography was developed in the late 1990s and is now increasingly available in clinical practice. It can provide high resolution cross-sectional images of teeth and the maxillofacial region with applications in all branches of dentistry. As a new imaging modality, there were no established suspension levels at a European level. A literature review, encompassing scientific, professional publications and existing national guidelines was performed in an attempt to develop a set of suspension levels for dental CBCT, using additional expert opinion from the members of the European Academy of dento-maxillo-facial radio…
In vitro carious lesion detection on D-, E-, and F-speed radiographic films
Abstract Objectives To compare the accuracy in detection of interproximal natural carious lesions in vitro between Ultraspeed (D), Ektaspeed Plus (E), and Insight (F) radiographic films. Study design Ten observers indicated on a 5-point scale their confidence in detecting an interproximal lesion in 240 surfaces (120 extracted teeth) with noncavitated carious lesions. Truth was assessed microscopically from hemisections. The areas (Az) beneath receiver operating characteristic (ROC) curves were pairwise compared and used for a 2-way analysis of variance. Results Az values were significantly correlated with observers ( P = .002; Eta = 0.671) and film type ( P = .003; Eta = 0.412). E differe…
Contrast perception in digitized panoramic radiographs compared with their film-based origin
Abstract Objectives. We sought to compare the visual image quality of film-based and digitized panoramic radiographs through use of a hole-containing test wedge. Study Design. An aluminum wedge containing 100 cells, of which 90 were given shallow holes, was exposed in the film-based Orthophos CD panoramic unit. Two radiographs subjectively exhibiting optimum contrast were selected. Films were digitized with a charge-coupled device flatbed scanner at 300 dpi. Films and digitized images were rated cellwise by 2 similar groups of 50 observers each with respect to spot perception. Results. The mean sensitivity was 0.26 ± 0.09 for film and 0.20 ± 0.07 for digitized images (P =.000), with a prono…
Mathematical analysis of projection errors in “paralleling technique” with respect to implant geometry
Abstract: “Standardized” radiographs acquired in paralleling technique serve for monitoring of marginal bone levels around endosseous implants. Under clinical conditions, parallel adjustment of the film to the implant is beset with great difficulties. A mathematical model matching clinical conditions was developed to evaluate projection geometry within an interval of clinically relevant angulations (± 10° from parallel position). Radiographs of two implants (Frialit 2, Friadent AG, Mannheim, Germany; Implant No. 1: ∅ 3.8 mm, length 10 mm; Implant No. 2: ∅ 6.5 mm, length 13 mm) were separately produced per angulation (2° increments) at one focus-object distance (FO=322.9 mm). Implant images …
B-mode versus A-mode ultrasonographic measurements of mucosal thickness in vivo
Abstract Objective: The objective of this study was to compare the measurement accuracy of A-mode and B-mode ultrasonographic assessments of palatal masticatory mucosal thickness in vivo. Study Design: Thickness of palatal masticatory mucosa in the molar region of 50 volunteers was measured once with a B-mode ultrasound device (10 MHz) combined with a standoff for intraoral applications. At identical reading points thickness was also assessed with an A-mode device (5 replicates) and by needle probing for determination of true thickness. Results: On average true thickness ranged between 2.9 and 3.3 mm (95% confidence intervals; median, 3.1 mm). B-mode ultrasonography overestimated truth by 0…