Dental Film Research Articles

Effects of viewing conditions on the detection of contrast details on intraoral radiographs

To quantify the effects of changes in the viewing environment on the detectability of diagnostic information on intraoral radiographs. Radiographs of a dental Burger’s phantom were taken using two kinds of dental film at 60, 70, and 80 kV each. Radiographs with optical densities of 0.5, 1.0, 1.5, 2.0, and 2.5 were taken using each type of film. An observer test was performed using a viewbox with an illumination of 10 000 lx under three conditions: (1) in a lit room without viewbox masking (not blocking the light around the radiograph); (2) in a lit room with viewbox masking (blocking the light around the radiograph); and (3) in a darkened room with viewbox masking (blocking the light around the radiograph). Optical densities of 0.5–1.0, 0.5–1.5, and 0.5–2.0 (or 0.5–2.5) were defined as underexposure, optimal exposure, and overexposure, respectively. The following results were obtained: (1) irrespective of the viewing conditions, the detectability was lowest on underexposed radiographs, while the detectability on optimally exposed and overexposed radiographs was 2.5–3.5 times higher; (2) masking the viewbox in a lit room increased the detectability on underexposed, optimally exposed, and overexposed radiographs by 8%, 14%, and 25%–47%, respectively, compared with that in the unmasked condition; and (3) with masking of the viewbox in a darkened room, the detectability on underexposed radiographs remained unchanged, while the detectability on optimally and overexposed radiographs increased by 8% and 24%–54%, respectively, compared with that in the unmasked condition in a lit room. The detectability was higher on radiographs of regions of interest taken with an optical density of at least 1.0.

Resolution of digitized intraoral dental films

Letter to the EditorResolution of digitized intraoral dental filmsJohn B Ludlow and André MolJohn B LudlowDepartment of Diagnostic Sciences and General Dentistry University of North Carolina School of Dentistry Chapel Hill, NC 27599-7450 USASearch for more papers by this author and André MolDepartment of Diagnostic Sciences and General Dentistry University of North Carolina School of Dentistry Chapel Hill, NC 27599-7450 USASearch for more papers by this authorPublished Online:28 Jan 2014https://doi.org/10.1259/dmfr/36572583SectionsPDF/EPUBFull Text ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail About"Resolution of digitized intraoral dental films." Dentomaxillofacial Radiology, 33(3), p. 208

Angioedema without urticaria in 929 patients: Description and proposal for a diagnostic approach

Rationale Angioedema without major urticaria flares is poorly characterized and few data exist on the underlying etiopathogenetic mechanisms. Here we report our experience on this condition and propose a diagnostic-therapeutic approach. Methods 929 consecutive patients were examined at our outpatient clinic for recurrent angioedema without urticaria between 1993 and 2002. Known causes of angioedema were identified by clinical history with detailed information about personal and familial allergies, relationship of angioedema to potential causative agents, complete physical examination, routine laboratory tests (blood cell count, protein electrophoresis, erythrosedimentation rate, stool for ova and parasites, pharyngeal and urine cultures, sinus and dental film, anti-tissue autoantibodies, rheumatoid factor), complement parameters (C1 inhibitor, C4, C1q). Further testing was done when pertinent. When all was negative, response to H1-antihistamine was considered. Results According to our testing angioedema were classified as follow: related to external agents (drugs, insect stings, food) 209 (22.5%) (85 of them were related to treatment with an ACE-inhibitor); associated to autoimmune diseases or infections 77 (8.2%); hereditary C1 inhibitor deficiency 183 (19.6%); acquired C1 inhibitor deficiency 14 (1.5%); idiopathic histaminergic 253 (27.2%), idiopathic non histaminergic 40 (4%). 153 patients (16.4%) dropped out from the study and could not be classified. Conclusions Based on the frequency of the different diagnosis we propose the following progression of testing: 1. anamnestic identification of causative agents, 2. testing for complement abnormalities, 3. H1 antagonist treatment, 4. complete diagnostic workup.

An In Vitro Evaluation of the Diagnostic Quality Ultra-Speed Versus Insight Intraoral Dental Film

Twelve sets of FMS (full mouth survey) radiographs were taken by California licensed radiology technicians. Ten of the sets of FMS radiographs were taken using Ultra-Speed "D" film on the left side of the patient and Insight "F" speed film on the right side of the patient. The remaining two sets of films were taken using Insight Film on both sides of the patient to act as a control. Ten faculty members of the Diagnostic Department were asked to evaluate the twelve sets of FMS radiographs and report whether they had a preference for the right side, left side, or no preference. Criteria for preference were diagnostic ability and clarity of the films. The results of the study showed a preference for the right side (65.7%), which was imaged with Insight Film, compared to the left side (34.3%), which was imaged with Ultra-Speed Film.

Intra-oral and extra-oral digital imaging:: an overview of factors relevant to detector design

Since the introduction of the first intraoral detector system 15 years ago, major improvements have been achieved. Initially, fibre optic coupling was used between the entrance phosphor and the small CCD sensor, later sensors became available for direct exposure. Also the dimensions of the active area were increased to comply with the size of analogue dental films and the thickness of the sensor was decreased. Intraoral films are flexible, CCD-type sensors however, are stiff and therefore much more difficult to position in the mouth of the patient. The resolution of modern intraoral sensors is comparable or even higher than that of film, but with increasing resolution, noise is becoming a problem in some diagnostic tasks.Both imaging phosphor plates and CCD-based systems are also used in extra oral imaging. The procedures in phosphor plate technology are quite comparable to those of conventional film. As the width of CCD sensors is limited, a slit imaging technique is used in panoramic imaging and still images. Tomography, a radiographic method to display layers within an object is not possible with the present CCD sensors.

Digital tomosynthesis-experiences with a new imaging device for the dental field.

Based on the principles of classic film tomography, a new digital X-ray device for dental sites was developed and clinically evaluated. The tomosynthesis process produces several slices from a finite number of radiographs taken from different projection angles, obtaining a three-dimensional image of the jaws and teeth. During evaluation of an industrial prototype, a total of 52 tomosynthesis data sets were made covering different anatomic areas. Of those, 32 sets were assessed by ten radiologically experienced dentists. Anatomic regions not shown on conventional intraoral dental films were displayed due to the extraoral sensor. Diagnostic images of high value were mainly achieved within the scope of lateral views and transverse views in the frontal region. Even small structures such as the periodontal ligament could be shown in several planes, resulting in superposition-free representation. The elimination of metal artefacts caused by dental restorations was facilitated. However, improvements can be made in definition and resolution. Views in the sagittal plane and incomplete blurring of the contralateral jaw are difficulties that remain. The tomosynthesis process combined with a planned 3D representation is likely to be well suited for dental radiology. The use of such a device could be much less expensive than computed tomography (CT). Furthermore, it offers higher spatial resolution, exposes patients to less radiation, and could be easily used in daily practice, even chairside.

Intrapulpal temperature changes during root surface irradiation with an 809-nm GaAlAs laser.

The aim of this study was to explore, in vitro, whether the irradiation of human root surfaces with a diode laser might induce nonphysiologic intrapulpal temperature elevations and, therefore, jeopardize pulp vitality. The pulps were removed from human maxillary and mandibular incisors extracted for periodontal reasons. The root canals were enlarged to an apical size #60 file. The teeth were radiographed with standard dental films and a millimeter grid to determine root thickness. The thickness of dentin between the root surface and the pulp in the irradiation areas was 1, 2, and 3 mm. To determine intrapulpal temperature changes during laser irradiation, 0.5-mm K-type thermocouples were inserted. An 809 nm GaAlAs laser with a 400-micron optical fiber was used. The power output varied between 0.5 and 2.5 W in the continuous-wave mode (0 Hz). Irradiation was continued for up to 120 seconds. Temperature elevations between 0.5 and 32.0 degrees C were registered in an energy- and time-dependent manner. Dentin thickness had a significant effect on intrapulpal temperature changes (Mann Whitney U test, P <.05), with a thinner dentin layer resulting in higher temperature elevations. Diode-laser irradiation may jeopardize pulp vitality. It must be recommended to limit power output to 0.5 W and the time of irradiation to 10 seconds when lasing the root surfaces of lower incisors and first maxillary premolars. With other teeth, a power output of 1.0 W and an exposure time of 10 seconds must not be exceeded to ensure a safe clinical application.

The canal system of mandibular incisors

The purpose of this study is to identificate root canal system including ideal access placement, root curvature, canal configuration, incidence of isthmus in mandibular incisors for success of endodontic treatment. 200 mandibular incisors were selected. The ideal access placement was determimed as follows. The teeth there radiographed from mesiodistal and buccolingual views using intraoral dental film. The image was divided into coronal, middle and apical third using the proximal film. Straight line access was determined by measuring the faciolingual canal width and placing points at midway point between the buccal and lingual wall at the junction of the middle and apical third and at the juntion of coronal and middle third of the root canal. A line was drawn connecting these two points extending through the crown of the tooth. The point at which the line crossed the external crown surface was recorded as facial, incisal, lingual. Degree of root curvature was determined by Schneider Protractor Method. Both section method and clearing method were used in this study. By section method, 100 mandibular incisors were embedded in clear resin and transeverse serial sectioned at 0.5, 1.0, 2.0, 3.0, 4.0, 5.0mm level from root apex. The resected surfaces were stained by methylene blue and examined under 40 magnification with a stereomicroscope. By clearing method, 100 mandibular incisors were cleared in methysalicylate after decalcification with 10% nitric acid and evaluated under 18 magnification with a stereomicroscope. The results were as follows ; 1. 29% had the center of the plotted straight-line access facial to incisal edge, whereas 71% had straight-line access at the incisal edge. When incisal wear classified as extensive, the straight-line access was plotted on the incisal edge 95.5%. When incisal wear classified as slight/none, the straight-line access was plotted on the facial 65.9%. 2. Degree of curvature of main canal was straight or almost straight, and only 10% in buccolingual direction had a degree of curvature greater than 20 degrees and 5.5% in mesiodistal direction had. 3. In section method, canal configuration analysis showed that 51% of the specimen classified as type I, 27% as type II, 12% as type III, 10% as type IV. For theses setions with two canals, the incidence of an isthmus was 36.7%, 64.3%, 79.2%, 96.3%, 97.4%, 97.6% at each level and highest in 3~5mm sections. 4. In clearing method, canal configuration analysis showed that 74% of the specimen classified as type I, 11% as type II, 6% as type III, 9% as type IV. These results suggested that traditional access from lingual should be moved as far toward the incisal as possible to locate and debride the lingual canal and root canal system should be cleaned, shaped completely and obturated three dimensionally for successful endodontic treatment.

Potential Risk for Lead Exposure in Dental Offices

In December 2000, the Washington State Health Department discovered white powder that was found to be lead oxide in boxes used to store dental intraoral radiograph film. The Washington State Health Department alerted state health departments throughout the United States. Subsequently, the Wisconsin Division of Public Health (WDPH) conducted an investigation of dental offices in the state. This report summarizes the investigation, which indicated that similar storage boxes are used in Wisconsin. The findings indicate that patients are at risk for exposure to a substantial amount of lead during a dental radiograph procedure if the office stores dental film in these boxes.

Prevalence of odontoclastic resorptive lesions in a population of clinically healthy cats.

The prevalence of odontoclastic resorptive lesions (ORLs) was determined in a clinically healthy cat population (228 cats) using both clinical (oral examination) and radiographic (full-mouth series with intraorally positioned dental film) methods. The overall prevalence rate was 29 per cent (mean age of the cat population 4.9 years). The mandibular third premolars (307, 407) were the most commonly affected tooth and the pattern of ORL development was symmetrical in most cats. The risk of having ORLs was found to increase with increasing age and cats with clinically and radiographically missing teeth were more likely to have the condition. Neutering, gender, age at neutering or mean whole mouth gingivitis index did not affect the prevalence of ORLs.

Sensitometric comparison of speed group E and F dental radiographic films

Sensitometric comparison of speed group E and F dental radiographic films

Sensitometric evaluation of a new F-speed dental radiographic film

Sensitometric evaluation of a new F-speed dental radiographic film

Comparação entre filmes radiográficos e o sistema digital Digora, no diagnóstico de lesões de cárie dentinária em superfície proximal de molares decíduos

O estudo comparou o desempenho diagnóstico dos filmes Agfa M2 e Ektaspeed Plus e do sistema digital Digora. A amostra foi composta por 37 molares decíduos, radiografados em 50, 70 e 90 kV. As imagens de 41 superfícies proximais foram avaliadas sob condições padronizadas. Cinco recursos de edição de imagem (0,5 X, 1 X, 2 X, "Negativo" e 3D), disponíveis no software do sistema digital, foram utilizados. Após a secção dos dentes e a validação em estereomicroscopia (40 X), calculou-se a sensibilidade, especificidade, acurácia e kappa não-ponderado dos métodos. O filme Ektaspeed Plus, exposto a 50 kV, diferenciou-se devido aos valores expressos para sensibilidade, acurácia e kappa não-ponderado. A especificidade dos filmes revelou valores comparáveis. Com a utilização do sistema digital Digora, a taxa de diagnósticos positivo-verdadeiros alcançou maior valor ao ser utilizado o recurso de imagem "Negativo". A imagem comprimida (0,5 X) foi, majoritariamente, a mais específica. As acurácias médias do sistema digital Digora resultaram em valores aproximados. Ao ser utilizada a estatística kappa, não houve distinção entre os recursos de imagem obtidos com o software. O método digital foi mais sensível que os filmes, porém, estes foram mais específicos. A acurácia média do sistema digital suplantou a dos filmes. Excetuando-se o Ektaspeed Plus, em 50 kV, os filmes não alcançaram os valores de kappa demonstrados pelo sistema digital Digora. Cohen’s kappa revelou boa concordância intra-examinador (0,758). Devido aos resultados observados, o sistema digital demonstrou-se comparável ao método radiográfico convencional, no diagnóstico de lesões de cárie dentinária em superfícies proximais de molares decíduos.

Radiographic detection of approximal caries: a comparison of dental films and digital imaging systems

Radiographic detection of approximal caries: a comparison of dental films and digital imaging systems

Radiographic detection of approximal caries: a comparison of dental films and digital imaging systems

To compare the diagnostic accuracy for the detection of approximal caries of two dental X-ray films, two CCD-based digital systems and two storage phosphor (SP) digital systems. Fifty-six surfaces in 56 extracted unrestored premolars were radiographed under standardised conditions using two E-speed dental film, Ektaspeed Plus (Eastman Kodak Co, Rochester, NY, USA) and Dentus M2 Comfort (Agfa-Gevaert, Mortsel, Belgium), two CCD systems, Sidexis (Sirona, Bensheim, Germany) and Visualix (Gendex, Milan, Italy) and two SP systems, Digora (Soredex, Helsinki, Finland) and DenOptix (Gendex, Milano, Italy). The images were assessed by eight observers (four radiologists and four general practitioners). True caries depth was determined by histological examination. True caries depth was subtracted from the values given by the observers and an analysis of variance was performed. The null hypothesis was rejected when P < 0.05. No significant differences were found in diagnostic accuracy with the two dental films and the Sidexis and Digora systems. The depth of the lesion significantly affected observer performance. Caries depth was underestimated. Radiologists performed significantly better than general practitioners whatever the recording system. The diagnostic accuracy of digital systems is comparable with that of dental films. The ability of dentists to recognise caries correctly is the main factor contributing to variation in radiographic diagnosis and not the imaging modality.

DIGITAL IMAGING FOR DENTAL CARIES

Laboratory studies show that digital intraoral radiography systems are as accurate as dental film for the detection of caries when a good-quality image is obtained, although more re-takes might be necessary because of positioning errors with the digital systems, particularly the charge-coupled device sensors. The phosphor plate is more comfortable for the patient than nondigital systems, and the dose can be further reduced with the storage phosphors. Cross-contamination does not pose a problem with digital systems if simple hygiene procedures are observed.

Digitisation and display of intra-oral films.

To determine the optimal parameters for the digitisation and display of intra-oral radiographs. Six intra-oral radiographs (EP size 2 dental film, Eastman Kodak Co., Rochester, NY, USA) were digitised using an Arcus II image scanner (Agfa-Gevaert N. V., Mortsel, Belgium). Each film was digitised at 8 bits, with and without a film mask, using three scanner resolutions (200, 400 and 600 p.p.i.), resulting in six versions of each radiograph. Seven experienced observers were asked to evaluate the quality of the resulting images as they were displayed on a Nokia 445Xi monitor (Nokia Display Products, Helsinki, Finland). Monitor settings were varied by changing the colour palette and screen resolution. Digital images of masked films had a statistically significant (t-test with alpha 2 tail < or = 0.05) higher quality than those scanned without a mask. The best image quality was obtained at a resolution of 400 p.p.i. Display options were optimum with 256 colours and a screen size of 1152 x 864 pixels. Better results were obtained when intra-oral radiographs were digitised with a mask at a resolution of 200 or 400 p.p.i. and displayed using 256 colours and the largest screen size possible. Further studies are needed to extend these results to other makes and models of scanner and monitor.

Conventional dental radiography and future prospectives

Until recently, conventional dental radiology was performed by dentists and orofacial surgeons. Due to the rapid development of radiological technique, the demand of radiological advice is increasing. The radiologists see more and more dental patients in their daily routine. The aim of this article is to give an overview on established dental radiology and a glimpse into the future. Conventional dental radiology and digital radiography are presently in use. Intraoral technique comprises dental films, bite-wing views and occlusal radiographs. Panoramic views and cephalometric radiographs are done with extraoral technique. Digital radiography lacks all processes in behalf of film development. It leads to dose reduction and enables image manipulation.

Modified Intraoral Film Holders for Postmortem Identification

To date there have not been any commercial dental X-ray film holders marketed to accommodate the special needs of forensic odontologists. Modification of standard Rinn XCP film holders by the investigators produced self-supporting film holders that do not require the active participation from the examinee. The modified film holders greatly simplify the operator's technique of exposing dental radiographs on cadavers.

The effect of developer age on the detection of approximal caries using three dental films

The effect of developer age on the detection of approximal caries using three dental films