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Quality Aspects of Digital Radiography in General Dental Practice
Malmö högskola, Faculty of Odontology (OD).ORCID iD: 0000-0001-9885-0019
2007 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [sv]

POPULÄRVETENSKAPLIG SAMMANFATTNINGDet övergripande syftet med denna avhandling var att klargöra hur digital röntgenteknik används hos allmäntandläkaren och framför allt har syftet varit att undersöka kvaliteten hos röntgenbilderna och hur den skulle kunna förbättras. I det första arbetet studerades digitala röntgenbilder som var inskickade i samband med förhandsprövningar till Försäkringskassan. Dessa var signifikant sämre när det gällde bildkvalitet än röntgenbilder tagna med film. Då riktades uppmärksamheten på vad som kunde vara problemet och en enkät skickades ut till samtliga tandläkare i Skåne som enligt ett brev hade svarat att man arbetade med digital röntgenteknik (n=139). De viktigaste fynden i enkäten var att ca 30 % av tandläkarna hade problem med den digitala detektorn och programmen. 20 % hade problem med datorerna. Enbart 40 % av tandläkarna gjorde någon form av kvalitetskontroll. Som en följd av enkätsvaren från tandläkarna besöktes 19 slumpmässigt utvalda tandläkare som arbetade med digital röntgenteknik, inom både folktandvården och privattandvården. Där fann vi att bakgrundsbelysningen hade stor betydelse för möjligheten att urskilja lågkontrastobjekt vilket är likvärdigt med kariesskador. Dessutom visade det sig att monitorn har stor betydelse för bildkvaliteten. Det finns möjlighet att ställa in monitorn med hänsyn till parametrarna kontrast och ljusstyrka. Dessa visade sig vara mycket viktiga när det gäller att optimera det digitala systemet. Dagens bildbehandlingsprogram har många möjligheter till justering av bilder. Tandläkarna ändrade, om något, ljus och kontrast. Det fanns många och stora variationer mellan de besökta klinikerna när det gällde bildkvalitet och hur man arbetade med digital röntgenteknik.I det sista arbetet undersöktes hur stor betydelse en riktigt inställd monitor och belysningen har när man diagnostiserar karies. Studien gjordes med hjälp av extraherade tänder som röntgenundersöktes och granskades av sju tandläkare. Fynden visade att bakgrundbelysningen i rummet har stor betydelse för möjligheten att diagnostisera kariesskador. Diagnostiken blev bättre när granskningen skedde i dämpad belysning och när monitorns ljusstyrka och kontrast var rätt justerad. Sammanfattningsvis så gäller det att säkerställa bildkvaliteten på digitala röntgenbilder. Det krävs en omfattande utbildning när man ska börja arbeta med en helt ny teknik. Det måste finnas utrymme för en inkörningsperiod och en vilja till att lära sig den nya tekniken. Den digitala röntgentekniken påverkas av många fler faktorer än traditionell filmteknik när gäller den slutliga röntgenbildens kvalitet.

Abstract [en]

ABSTRACTThe number of dentists who have converted from conventional film radiography to digital radiography continues to grow. A digital system has numerous advantages, but there are also many new aspects to consider. The overall aim of this thesis was to study how digital radiography was used in general dental practices. The specific aims were to study how different factors affected image quality.To determine whether there were any differences in image quality between conventional film radiographs and digital radiographs, 4863 images (540 cases) were evaluated. The cases had been sent to the Swedish Dental Insurance Office for prior treatment approval. The image quality of digital radiographs was found to be significantly lower than that of film radiographs. This result led to a questionnaire study of dentists experienced in digital radiography. In 2003, a questionnaire was sent to the 139 general practice dentists who worked with digital radiography in Skåne, Sweden; the response rate was 94%. Many general practice dentists had experienced several problems (65%), and less than half of the digital systems (40%) underwent some kind of quality control. One of the weaker links in the technical chain of digital radiography appeared to be the monitor. A field study to 19 dentists at their clinics found that the brightness and contrast settings of the monitors had to be adjusted to obtain the subjectively best image quality. The ambient light in the evaluation room was also found to affect the diagnostic outcome of low-contrast patterns in radiographs.To evaluate the effects of ambient light and technical adjustments of the monitor, a study using standardised set-ups was designed. Seven observers evaluated radiographs of 100 extracted human teeth for approximal caries under five different combinations of brightness and contrast settings on two different occasions with high and low ambient light levels in the evaluation room. The ability to diagnose carious lesions was found to be significantly better in a room with lower ambient light and on a monitor with well-adjusted brightness and contrast values than in a room with bright light and on an unadjusted monitor.In conclusion, many problems with dental digital radiography were identified. Knowledge of digital techniques and how to optimise each link in the system to maintain high radiographic quality at all times must be improved.

Place, publisher, year, edition, pages
Malmö University , 2007. , p. 91
Series
Swedish Dental Journal : Supplement, ISSN 0348-6672 ; 184
Keywords [en]
Digital radiography
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
URN: urn:nbn:se:mau:diva-7748Local ID: 4693ISBN: 91-7104-291-1 (print)OAI: oai:DiVA.org:mau-7748DiVA, id: diva2:1404689
Note

Paper IV in dissertation as manuscript

Available from: 2020-02-28 Created: 2020-02-28 Last updated: 2024-03-14Bibliographically approved
List of papers
1. Image Quality of Digital and Film Radiographs in Applications Sent to the Dental Insurance Office in Sweden for Treatment Approval
Open this publication in new window or tab >>Image Quality of Digital and Film Radiographs in Applications Sent to the Dental Insurance Office in Sweden for Treatment Approval
2004 (English)In: Swedish Dental Journal, ISSN 0347-9994, Vol. 28, no 2, p. 77-84Article in journal (Other academic)
Abstract [en]

In July 2002, a new dental insurance program was introduced in Sweden. For all patients over 65 years, prior approval for all prosthetic work would need to be obtained from the Dental Insurance Office. From October to December 2002, 540 cases were randomly selected for evaluation from the 14,624 applications that had been sent from throughout Sweden to the Dental Insurance Office in Lund. Our aims were to appraise the quality of the radiographic examinations and to compare the quality of the digital with the film (X-ray film) radiographs. The radiographic examinations were evaluated as a whole in relation to the proposed treatment and in detail using specific criteria such as density, contrast, unsharpness, angulation, and receptor position error. The quality variables were evaluated as acceptable or unacceptable. A total of 4,687 intra-oral and 206 panoramic radiographs were evaluated. Thirteen per cent of the intra-oral radiographs and 9% of the panoramic radiographs were taken with a digital technique. Most of the digital radiographs—-70% of the intra-oral and 61% of the panoramic radiographs-—were submitted on microdisk. Twentyeight per cent of the intra-oral digital radiographs, however, were submitted on paper. The radiographic quality in 150 cases (28%) were found to be unacceptable for assessment of the proposed treatment. The most common error-—both in digital and X-ray film radiographs-—was in receptor position. Significantly more errors were found in the intra-oral digital radiographs compared to the radiographs taken with X-ray film. Most of the errors in the digital radiographs were detected in the paper copies. In conclusion, it is possible to improve the radiographic quality in applications for treatment approval, and the dentists had more difficulties with the digital technique than with X-ray film.

National Category
Dentistry
Identifiers
urn:nbn:se:mau:diva-15419 (URN)3045 (Local ID)3045 (Archive number)3045 (OAI)
Available from: 2020-03-30 Created: 2020-03-30 Last updated: 2024-03-14Bibliographically approved
2. Dental digital radiography: a survey of quality aspects
Open this publication in new window or tab >>Dental digital radiography: a survey of quality aspects
2005 (English)In: Swedish Dental Journal, ISSN 0347-9994, Vol. 29, no 2, p. 81-87Article in journal (Refereed)
Abstract [en]

The aim was to evaluate the experiences of Swedish general dental practitioners (GDPs) with digital radiography and their opinion on the same, particularly regarding quality issues. A letter was sent to all GDPs in private care in Region Skåne, Sweden, asking whether they used digital radiography (n=513). The response rate was 79%. The number of private GDPs who replied that they used digital radiography was 106. The Public Dental Service in Region Skåne listed 33 GDPs who worked with digital radiography. Based on these answers, a questionnaire was sent to the GDPs working with digital radiography (n=139). The questionnaire comprised 27 questions about the dentists, the system of intra-oral digital radiography, and the GDPs’ experiences of and opinions on issues regarding image quality and quality control. The response rate to the questionnaire was 94%. Almost all, 92%, worked with charge-coupled device (CCD) and complementary metal oxide semiconductor (CMOS) sensors. Most GDPs were satisfied with their digital radiographic system. The majority (65%) experienced problems. Detector failure and trouble with the software were common. The GDPs wrote that they used lower exposure times in digital radiography than traditional film radiography. The estimated reduction in exposure time was said to be between 51% and 75%. Thirtyfive per cent continued to use film parallel with digital radiography. The answers indicated that less than half of the equipment (40%) underwent quality control. Quality controls, when conducted, were undertaken once or twice a year, mainly by technicians from the companies that had sold the digital equipment. Based on the results of the questionnaire, there seems to be a need to improve the maintenance and the quality of digital radiography. It is also important that the GDPs become more aware of the problems that can occur when a new technique is introduced and that they develop the skills to handle these problems.

National Category
Dentistry
Identifiers
urn:nbn:se:mau:diva-5877 (URN)3030 (Local ID)3030 (Archive number)3030 (OAI)
Available from: 2020-02-28 Created: 2020-02-28 Last updated: 2024-03-14Bibliographically approved
3. Digital radiography in general dental practice. A field study
Open this publication in new window or tab >>Digital radiography in general dental practice. A field study
2007 (English)In: Dento-Maxillo-Facial Radiology, ISSN 0250-832X, E-ISSN 1476-542X, Vol. 36, no 5, p. 249-255Article in journal (Refereed)
Abstract [en]

Abstract Objectives: The aim of this study was to conduct a field study to survey the performance of digital radiography and how it was used by dentists in general dental practice. Methods: Nineteen general dental practitioners were visited at their clinics. Ambient light (illuminance) was measured in the rooms where the monitors were placed. Different technical display parameters were noted. Test images and two phantoms—one low-contrast phantom and one line-pair resolution phantom—were used to evaluate the digital system. How the dentists used the enhancement program was investigated by noting which functions were used. Results: Average illuminance in the operating room was 668 lux (range 190–1250 lux). On radiographs of the low-contrast phantom taken at the clinic, the ability to observe the holes decreased as illuminance increased. On average, the “light percentage” initially set on the monitor had to be decreased by 17% and contrast by 10% to optimise the display of the test images. The general dental practitioners used the enhancement programs most often to alter brightness and contrast to obtain the subjectively best image. Large differences between the clinics were noted. Conclusion: Knowledge of how to handle digital equipment in general dental practice should be improved. A calibrated monitor of good quality should be a given priority, as should proper ambient light conditions. There is a need to develop standardised quality controls for digital dental radiography. Key-words: display monitor, enhancement program, digital radiography, quality

Keywords
Digital radiography
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:mau:diva-15872 (URN)10.1259/dmfr/95125494 (DOI)000248510400001 ()17586850 (PubMedID)2-s2.0-34547665116 (Scopus ID)4694 (Local ID)4694 (Archive number)4694 (OAI)
Available from: 2020-03-30 Created: 2020-03-30 Last updated: 2024-03-14Bibliographically approved
4. Effect of ambient light and monitor brightness and contrast settings on the detection of approximal caries in digital radiographs: an in vitro study
Open this publication in new window or tab >>Effect of ambient light and monitor brightness and contrast settings on the detection of approximal caries in digital radiographs: an in vitro study
2008 (English)In: Dento-Maxillo-Facial Radiology, ISSN 0250-832X, E-ISSN 1476-542X, Vol. 37, no 7, p. 380-384Article in journal (Refereed)
Abstract [en]

Objectives: The aim of this study was to investigate how brightness and contrast settings of the display monitor and ambient light level (illuminance) in the viewing room affect the clinician's ability to diagnose carious lesions in digital radiographs. Methods: Standardized radiographs were taken of 100 extracted teeth. Seven observers evaluated the images for approximal carious lesions twice, once under 50 lux and once under 1000 lux room illumination. Monitor brightness and contrast were varied ±50% and ±6%, respectively, to mimic the normal limits of monitor adjustment by an inexperienced user and one optimal setting. This was done by adjusting radiograph brightness and contrast by ±25%. Thus, five radiographs of each tooth were evaluated. Receiver operating characteristic (ROC) analyses were performed. Histological examinations of the teeth served as the criterion standard. A paired t-test was used to evaluate whether differences in the areas under the ROC curves were significant and kappa was used to evaluate intraobserver agreement. Results: When a monitor with optimal brightness and contrast settings was used to detect approximal carious lesions, ambient light levels less than 50 lux were significantly better than levels above 1000 lux (dentin and enamel lesions, P < 0.01; dentin lesions, P < 0.02). Increasing the contrast setting of the monitor by 6% did not change these results; 50 lux was still significantly better than 1000 lux (enamel lesions, P < 0.01; dentin and enamel lesions, P < 0.02) for evaluating radiographs. Intraobserver agreement differed from fair to good. Conclusions: Reducing ambient light to less than 50 lux significantly increased the accuracy of diagnosing approximal carious lesions on a monitor with an optimal brightness setting and an optimal or slightly higher than optimal contrast setting.

National Category
Dentistry
Identifiers
urn:nbn:se:mau:diva-15834 (URN)10.1259/dmfr/26038913 (DOI)000260169800003 ()18812599 (PubMedID)2-s2.0-54849409500 (Scopus ID)6769 (Local ID)6769 (Archive number)6769 (OAI)
Available from: 2020-03-30 Created: 2020-03-30 Last updated: 2024-03-14Bibliographically approved

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