Biomedical subjects

A Wenzel

Publications and source records attributed to A Wenzel.

At least 37 records · Page 2Linked to original sources

PubMed2003

Bitewing examination with four digital receptors.

OBJECTIVES: To evaluate recording errors and patient discomfort during bitewing examinations using four digital receptors. METHODS: Seventy-eight patients had two bitewings taken on each side of the mouth with the intention of displaying the tooth surfaces from the distal surface of the canine to the distal surface of the most posterior molar, using four digital receptors, two charge-coupled device (CCD) and two photostimulable phosphor (PSP) systems. The patients scored their feelings of discomfort during the examination on a visual analogue scale. Receptor positioning errors in the sagittal plane were determined from the tooth surfaces present on each image and in the vertical plane from the presence of the alveolar bone crest. Cone positioning errors were determined from cone cuts. RESULTS: Canine and premolar surfaces were more often not depicted on the CCD images than on the PSP images (P<0.05). Cone cuts occurred in 19% of DenOptix images, in 9% of Digora images and in one Planmeca image. The bone crest was more often missing in the upper jaw on Planmeca images than on PSP images (P<0.01). In the lower jaw, Trophy images more often missed the bone crest than the other systems (P<0.05). Patients ranked the receptors as follows (with increasing discomfort): DenOptix, Planmeca, Digora and Trophy, with all being significantly different (P<0.05). CONCLUSIONS: It was more difficult to correctly position CCD sensors than PSP plates in the vertical plane, resulting in more images with missing alveolar bone crest. CCD sensors most often did not display the most anterior surfaces in a bitewing examination.

Adolescent↗

PubMed2003

Accuracy of digital and film panoramic radiographs for assessment of position and morphology of mandibular third molars and prevalence of dental anomalies and pathologies.

OBJECTIVES: To compare the accuracy of digital and film panoramic radiographs for determining (1) the position and morphology of mandibular third molars before surgical removal and (2) the prevalence of dental anomalies and pathologies. METHODS: Three hundred and eighty-eight third mandibular molars were available for examination. Position and morphology of third molars observed on film radiographs and on digital panoramic images from five systems (DenOptix, DigiDent, Digora, Dimax2 and Orthophos Plus) were recorded by two observers and were compared with surgeons' findings at the time of the operation (gold standard). One observer further recorded the prevalence of dental anomalies and pathologies on both imaging modalities. RESULTS: Few differences were found between the digital and film-based panoramic systems in the assessment of accuracy of position and morphology of mandibular third molars. The prevalence of dental anomalies and pathologies determined with the two modalities was roughly similar. CONCLUSION: The five digital panoramic systems evaluated in this study were equally as useful for third molar treatment planning and diagnosis of dental anomalies and pathologies as conventional film-based panoramic radiographs.

Adolescent↗

PubMed2003

Image quality of two solid-state and three photostimulable phosphor plate digital panoramic systems, and treatment planning of mandibular third molar removal.

OBJECTIVES: The purpose was to evaluate image quality of two solid-state (charge-coupled device (CCD)) and three photostimulable phosphor (PSP) plate digital panoramic systems, and to assess their utility for treatment planning before mandibular third molar removal. METHODS: 433 patients were randomly allocated to five digital systems: Dimax2 and Orthophos Plus (both CCD systems) and DenOptix, DigiDent and Digora (all PSP systems). Image quality was evaluated in six regions on a 4-point scale by three independent observers. In addition, an oral surgeon evaluated image quality in the mandibular third molar region only as well as the utility of the image for treatment planning before removal of that molar. RESULTS: Images from the DenOptix and DigiDent systems had a significantly lower overall quality than images from the Digora, Dimax2 and Orthophos Plus systems (P < 0.005). The oral surgeon's assessment of image utility resulted in rejection rates of 0% for Orthophos Plus, 2% for Digora, 8% for Dimax2, 12% for DigiDent and 14% for DenOptix images. The rates for the DigiDent and DenOptix images were significantly higher than those for the other systems (P < 0.001), and the rate for Dimax2 was significantly higher than that for Orthophos Plus (P = 0.002). CONCLUSIONS: The quality of DenOptix and DigiDent digital panoramic images was found to be inferior to the quality found in images obtained with the Digora, Dimax2 and Orthophos Plus systems. Images from the Digora and Orthophos Plus systems were regarded to be the most useful for treatment planning before mandibular third molar removal.

Adolescent↗

PubMed2003

Integration of multiple direct digital imaging sources in a picture archiving and communication system (PACS).

OBJECTIVES: The aim of this report was to describe a flexible picture archiving and communication system (PACS) able to handle and communicate digital image data from various radiography systems and other sources. METHODS: The radiographic image is acquired using the vendor's own software. Following image capture, a "request for update" message (appending a record to an Access database) activates our PACS engine, "DigiMerge". Images from sources with no patient-related organizing software, e.g. TWAIN-compatible scanners and digital cameras, are handled by a self-developed program, "MedCom-T". DigiMerge generates and maintains one database based on all manufacturers' databases (software: VixWin 2000, Digora for Windows, Dimaxis Pro, Sidexis, CDR DICOM for Windows, Trophy for Windows). This database contains patient information, image information and image path. The program "DigiView" searches a patient and displays patient and image data from the database generated by DigiMerge. With DigiView, images can be viewed at any workstation in the dental school, but only temporary changes can be made (contrast, brightness, etc.) and no image can be deleted. RESULTS: The PACS is currently installed on 86 workstations. Statistics collected by DigiMerge reveal that approximately 2000 new digital images are recorded each month, half of which are radiographs and the other half are clinical photographs. Statistics collected by DigiView reveal that 500-800 digital images are opened per week. CONCLUSIONS: The self-developed PACS is able to manage images from a range of digital modalities each providing its own image data format.

Computer Systems↗

PubMed2003

Comparison of standard and task-specific enhancement of Digora storage phosphor images for approximal caries diagnosis.

OBJECTIVES: To compare approximal caries detection on Digora storage phosphor images pre-enhanced with the automatic "caries-specific Oslo enhancement procedure" ("Oslo-enhanced" method) and storage phosphor images individually enhanced by observers particularly experienced in digital imaging using standard brightness and contrast functions of the Digora system ("Digora-enhanced" method). METHODS: Seven staff members from four oral radiology departments rated 240 approximal surfaces for caries with regard to lesion depth in the inner and outer half of the enamel and dentine, using a 5-point confidence scale. The observations were validated histologically. A receiver operating characteristic (ROC) analysis and an analysis of variance with three dependent variables (observer confidence, observer signed error and observer absolute error) were performed. RESULTS: The most evident difference between the methods as elucidated by the ROC analysis was the highly significant smaller interobserver and intraobserver variance with the Oslo-enhanced method for all but one observer. The methods were not different with regard to average diagnostic accuracy (A(z) values) as tested with paired t-tests, and there was no correlation between A(z) across methods. The method and lesion main effects, as well as the lesion by method interaction effect, were multivariately significant (P<0.001) in favour of the Oslo-enhanced method. On a univariate level, the method main effect was not significant for the absolute observer error (P=0.330). All other univariate effects were significant (P<0.001). CONCLUSIONS: The accuracy of approximal caries detection with Digora storage phosphor images pre-enhanced and images individually enhanced was similar, but interobserver and intraobserver variability improved with the Oslo-enhanced method. Since image manipulation is not performed with the Oslo-enhanced method, the increased speed of the diagnostic procedure combined with the improved observer variability would probably be even more pronounced for the general dental practitioner.

Analysis of Variance↗

PubMed2002

Guided tissue regeneration in intrabony defects using an experimental bioresorbable polydioxanon (PDS) membrane. A 24-month split-mouth study.

AIM: The comparison of the clinical, radiographic, and microbiological healing results in deep intrabony defects following GTR therapy with two different bioresorbable membranes in a prospective split-mouth design. MATERIAL AND METHODS: 31 pairs of contralateral intrabony defects were randomly treated with either an experimental Polydioxanon (PDS) membrane or a Polylactic acid (PLA) matrix barrier. After 6, 12 and 24 months, healing results were assessed using clinical examinations (REC, PPD, CAL, vertical relative attachment gain V-rAG), quantitative digital subtraction radiography (amount and area of bone density changes), and microbiological analysis. RESULTS: Postoperative membrane exposures occurred in 14 PDS and 2 PLA treated sites. 6, 12 and 24 months p.o., both membranes provided a significant gain in CAL [median values: 6 months (PDS vs. PLA: 3.0 vs. 3.0 mm); 12 and 24 months (PDS vs. PLA: 4.0 vs. 4.0 mm)], which corresponded to a V-rAG of 57.1% (PDS) vs. 62.5% (PLA) after 24 months. PDS and PLA treated sites revealed significant bone density gain 6, 12 and 24 months after surgery. 38.8% (PDS) vs. 41.8% (PLA) of the initial defect areas showed bone density gain. While the gain in bone density was significantly greater in PDS than in PLA sites, neither CAL gain nor the area of bone density changes revealed significant differences. Microbiological culture revealed similar bacterial loads in PDS and PLA sites during the first 12 months. CONCLUSION: This 24-month study indicates that the PDS and PLA membranes can provide similar favorable regeneration results in deep intrabony periodontal defects, although considerably more postoperative membrane exposures have to be expected in PDS treated sites.

Absorbable Implants↗

PubMed2002

Influence of the validation method on diagnostic accuracy for caries. A comparison of six digital and two conventional radiographic systems.

OBJECTIVE: To evaluate the influence of the validation method on the diagnostic accuracy and the relative comparison of eight radiographic systems for caries detection. METHODS: Three hundred and thirty-eight approximal and 145 occlusal surfaces were radiographed under standardised conditions using six CCD-based sensor systems: MPDx (Dental/Medical Diagnostic Systems Inc., Woodland Hills, CA, USA), Dixi (Planmeca, Helsinki, Finland), Sidexis (Sirona, Bensheim, Germany), RVG(old) (Trophy, Paris, France, 1994 model), RVG(new) (Trophy, Paris, France, 2000 model) and Visualix (Gendex, Milan, Italy) and two film systems: Ektaspeed Plus and Insight (Eastman Kodak, Rochester, NY, USA). Four observers examined the radiographs for approximal and occlusal caries using a five-point confidence scale. The presence of caries was validated histologically and radiographically. Diagnostic accuracy was evaluated using ROC curve areas (A(z)). RESULTS: For both approximal and occlusal caries the mean A(z) of the eight radiographic systems was significantly higher using radiographic than histological validation (P<0.001). Using histological validation for approximal caries, Dixi (A(z)=0.71) and Ektaspeed Plus (A(z)=0.7) were not significantly different, but Dixi was significantly more accurate than the other digital systems and the Insight film. Using radiographic validation for approximal caries, Ektaspeed Plus (A(z)=0.87) was significantly more accurate than Dixi (A(z)=0.82). Dixi was significantly more accurate than MPDx (A(z)=0.74), RVG(old) (A(z)=0.77), RVG(new) (A(z)=0.77) and Visualix (A(z)=0.76). Corresponding variations were found for occlusal caries depending on the validation method. Using histological validation, MPDx (A(z)=0.76) was significantly less accurate than Dixi (A(z)=0.81), Sidexis (A(z)=0.8), Ektaspeed Plus (A(z)=0.82) and Insight (A(z)=0.81). Using radiographic validation, MPDx (A(z)=0.83) was also significantly less accurate than RVG(old) (A(z)=0.89) and RVG(new) (A(z)=0.9). CONCLUSION: A(z) obtained from radiographic validation was significantly higher than A(z) obtained from histological validation. Comparison of the diagnostic efficacy for caries of the eight radiographic systems was strongly influenced by the validation method. DOI: 10.1038/sj/dmfr/4600645

Analysis of Variance↗

PubMed2002

Accuracy of caries detection with four storage phosphor systems and E-speed radiographs.

OBJECTIVE: To evaluate the accuracy of caries detection using four intra-oral storage phosphor plate systems exposed with two different exposure times and one film system. METHODS: Under in vitro and standardised conditions 365 approximal and 159 occlusal surfaces were radiographed using four storage phosphor plate systems: DenOptix, Cd-dent, Digora (blue and white plates) and one film system: Ektaspeed Plus. The plates were exposed twice with 10% and 25% of the time needed for the film. Four observers recorded approximal enamel/dentine and occlusal dentine caries using a five-point confidence scale. Caries presence was validated histologically and diagnostic accuracy of the systems by using ROC curve areas (Az). RESULTS: The shorter exposure time for approximal caries, Digora(white)(Az=0.68) and Ekta Plus (Az=0.69) were significantly more accurate than the other systems (Az=0.64-0.65). For occlusal caries using the same exposure time, no significant difference was found between the digital systems (Az=0.76-0.77), which all showed to be significantly less accurate than Ekta Plus (Az=0.81). Using the longer exposure time for approximal caries, no significant difference was found between DenOptix (Az=0.68), Digora(blue) (Az=0.69), Digora(white) (Az=0.69) and Ekta Plus (Az=0.69) which were all significantly more accurate than Cd-dent (Az=0.65). For occlusal caries using the same exposure time, Digora(blue) (Az=0.81) was the most significantly accurate of the digital systems. When approximal caries was the diagnostic task, the longer exposure time resulted in significantly higher accuracy with the DenOptix and Digora(blue) systems but not with the Cd-dent and Digora(white) systems. For occlusal caries, the longer exposure time resulted in a significant improvement only with the Digora(blue) system. CONCLUSION: For approximal caries using the longer exposure time, no significant difference in diagnostic accuracy was found between DenOptix, Digora(blue), Digora(white) and Ekta Plus which were all significantly more accurate than the Cd-dent. For occlusal caries using the longer exposure time, Digora(blue) was found to be the most accurate of the digital systems. The exposure time had an influence on the diagnostic accuracy with the DenOptix and Digora(blue) systems for approximal and with the Digora(blue) system for occlusal caries detection.

Area Under Curve↗

PubMed2002

Electrocardiographic signs of hypertrophy in fabry disease-associated hypertrophic cardiomyopathy.

AIMS: Fabry disease results from deficient activity of the lysosomal enzyme alpha-galactosidase A. Progressive accumulation of the major substrates leads, in both men and women, to progressive hypertrophic cardiomyopathy. We aimed to evaluate the utility of different electrocardiographic (ECG) parameters for assessing the degree and severity of hypertrophic cardiomyopathy in patients with Fabry disease. METHODS: A total of 166 ECGs of 94 hemi- and heterozygous patients with Fabry disease were analysed and compared with echocardiographic-estimated left ventricular mass (LVM). RESULTS: There was a significant (p < 0.0001) correlation between QRS duration (R2 = 0.59), 12-lead amplitude/duration product (R2 = 0.61), Sokolow-Lyon voltage/duration product (R2 = 0.52) and LVM. Analysis of receiver operating characteristics revealed that the 12-lead amplitude/duration product had the highest sensitivity-specificity relationship (p < 0.01 compared with the Cornell index). CONCLUSION: In general, ECG signs of left ventricular hypertrophy correlated well with LVM as revealed by echocardiography. Of the parameters studied, the 12-lead amplitude/duration product was the most successful at describing the severity of cardiac involvement in Fabry disease. These data suggest that ECG parameters have potential for use as a simple and cost-effective means of screening for hypertrophic cardiomyopathy in patients with Fabry disease.

Adolescent↗

PubMed2002

[Improving signal-noise relations of evoked potentials by neural networks].

Single trial evoked potentials recorded in a sleep deprivation experiment were analyzed by means of neural networks. For improving the signal-noise-ratio a neural network classifier was trained to distinguish between the S-class which consists of assumed visually evoked single trial potentials and the N-class which should contain no event related components. The members of S-class and the N-class were averaged separately. We compared the averaged potentials of all single trials with the averaged potentials of the S-class members and we were able to show a significant improvement in the amplitudes and the signal-noise-ratio. We got the result that increasing sleep deprivation corresponds to a significantly decreasing number of members in the S-class. We concluded that sleep deprivation led to a significant number of stimuli which could not be preprocessed.

Artifacts↗

PubMed2002

Light damage susceptibility and RPE65 in rats.

A sequence variation in the pigment epithelial protein RPE65 has been shown to correlate with RPE65 protein levels, rhodopsin regeneration kinetics and light damage susceptibility in different mouse strains. Here, we tested whether such a correlation can also be found in rats. We examined four rat strains for RPE65 protein levels and the Rpe65 gene sequence. In two strains, we additionally determined Rpe65 mRNA levels, rhodopsin regeneration and light damage susceptibility (LDS).RPE65 protein levels were higher in Lewis and Brown Norway rats compared to Wistar and Long Evans. The albino strains Wistar and Lewis were investigated further. Lewis had higher Rpe65 mRNA levels than Wistar. Sequence analysis of the coding region of the Rpe65 cDNA revealed no relevant sequence variations in the two strains. Content and regeneration of rhodopsin were comparable in both strains. However, Wistar rats were more susceptible to light damage than Lewis. We conclude that lower RPE65 protein levels in Wistar may have been caused by decreased gene expression and not by a sequence variation as suggested for mice. In rats, RPE65 may not be a limiting factor for rhodopsin regeneration. Since LDS in rats did not directly correlate with RPE65 protein levels and rhodopsin regeneration, other yet unidentified (genetic) factors may account for the susceptibility differences observed in rats.

Amino Acid Sequence↗

PubMed2002

Genetic programming approach for the optimal selection of combinations of neuronal networks to classify sleep stages by QUISI.

The usefulness of a new way to optimize the cooperation of trained neural networks for automatic one-channel sleep stage analysis using genetic programming and performance evaluation by including the interrater reliability are the focus of our paper. The one-channel sleep classification could be significantly improved by the optimization. The software tool HENNE, with its genetic programming compartment was developed for this purpose. The tool has proved to be useful for searching for optima in difficult goal surfaces. To contribute to the general discussion about the benefit of the automatic one-channel sleep analysis on the basis of the frontal site, we tried to evaluate our results before the background of the interrater variability. Comparing the kappa statistics of different independent studies with our results, we concluded that there are no dramatic differences as a rule and that QUISI is a useful device as a presleep laboratory and ambulatory diagnostic tool.

Humans↗

PubMed2001

Predisposition to vasovagal syncope in subjects with blood/injury phobia.

BACKGROUND: Most subjects with blood/injury phobia experience syncope or presyncope as part of the phobic response. We tested the hypothesis that these subjects have a constitutional autonomic dysregulation that predisposes them to vasovagal syncope during head-up tilt. METHODS AND RESULTS: We studied 11 subjects (9 females, 2 males) who had a history of syncope or presyncope only in response to a blood or injury stimulus and 11 healthy matched controls (10 females, 1 male) without a history of syncope. Blood pressure (BP) and heart rate (HR) were measured during a 15-minute baseline period with subjects in the supine position and then during 45 minutes of head-up tilt to 70 degrees. Measurements at rest did not differ between the blood phobic and control subjects. During tilt, 9 (82%) of the 11 blood phobic subjects experienced presyncope or syncope, leading to termination of the study after 22+/-17 minutes of tilt. Only 1 (9%) of the 11 control subjects experienced presyncope (chi(2)=11.7, P=0.001). Hemodynamic responses to tilt were consistent with a vasovagal mechanism in the blood phobic subjects, with simultaneous decreases in BP and HR during tilt. During tilt, systolic BP fell by 21+/-15 mm Hg (P=0.001), and HR fell by 22+/-25 bpm (P=0.01). By contrast, BP and HR were very stable in the control group. CONCLUSIONS: Subjects with syncope related to blood/injury phobia have an underlying autonomic dysregulation predisposing them to neurally mediated syncope, even in the absence of any blood or injury stimulus. Fainting related to these stimuli may in large part be due to dysfunction in neural circulatory control, which may secondarily lead to the phobia because of repeated syncopal events.

Adult↗

PubMed2001

The Rpe65 Leu450Met variation increases retinal resistance against light-induced degeneration by slowing rhodopsin regeneration.

Excessive light can cause retinal degeneration and may be an environmental cofactor accelerating retinal dystrophies and age-related diseases. In rodent models, the light damage susceptibility (LDS) of the retina is determined genetically. In two mouse strains, with different degrees of LDS, a Leu450Met variation in the pigment epithelial protein RPE65 was shown recently to cosegregate with low LDS. Because light damage is rhodopsin-mediated, and RPE65 is essential for the regeneration of rhodopsin in the visual cycle, we analyzed this variation regarding rhodopsin metabolism and LDS in four mouse strains. We found that, in contrast to previous assertions, LDS does not correlate with the maximal retinal content of rhodopsin present after dark adaptation. Instead, LDS correlated positively with the kinetics of rhodopsin regeneration, which determine rhodopsin availability during light exposure. Light damage occurred after absorption of a threshold dose of photons and thus fast regeneration, as observed in those two strains having Leu at position 450 of RPE65, was correlated with the occurrence of photoreceptor apoptosis after short exposure. In contrast, mice with the Leu450Met variation of Rpe65 regenerated rhodopsin with slow kinetics and showed an increased resistance to light-induced retinal degeneration. In these mice, RPE65 protein levels were reduced by a post-transcriptional mechanism. F(1) hybrid mice, carrying one normal and one variant Rpe65 gene, had intermediate levels of the corresponding protein and showed intermediate rhodopsin regeneration kinetics and an intermediate LDS. Thus, none of the two variants of Rpe65 had a dominant effect.

Amino Acid Substitution↗

PubMed2001

New views on RPE65 deficiency: the rod system is the source of vision in a mouse model of Leber congenital amaurosis.

Leber congenital amaurosis (LCA) is the most serious form of the autosomal recessive childhood-onset retinal dystrophies. Mutations in the gene encoding RPE65, a protein vital for regeneration of the visual pigment rhodopsin in the retinal pigment epithelium, account for 10-15% of LCA cases. Whereas previous studies of RPE65 deficiency in both animal models and patients attributed remaining visual function to cones, we show here that light-evoked retinal responses in fact originate from rods. For this purpose, we selectively impaired either rod or cone function in Rpe65-/- mice by generating double- mutant mice with models of pure cone function (rhodopsin-deficient mice; Rho-/-) and pure rod function (cyclic nucleotide-gated channel alpha3-deficient mice; Cnga3-/-). The electroretinograms (ERGs) of Rpe65-/- and Rpe65-/-Cnga3-/- mice were almost identical, whereas there was no assessable response in Rpe65-/-Rho-/- mice. Thus, we conclude that the rod system is the source of vision in RPE65 deficiency. Furthermore, we found that lack of RPE65 enables rods to mimic cone function by responding under normally cone-isolating lighting conditions. We propose as a mechanism decreased rod sensitivity due to a reduction in rhodopsin content to less than 1%. In general, the dissection of pathophysiological processes in animal models through the introduction of additional, selective mutations is a promising concept in functional genetics.

Animals↗

PubMed2001

AP-1 mediated retinal photoreceptor apoptosis is independent of N-terminal phosphorylation of c-Jun.

Apoptosis is essential for retinal development but it is also a major mode of cell loss in many human retinal dystrophies. High levels of visible light induce retinal apoptosis in mice and rats. This process is dependent on the induction of the transcription factor AP-1, a dimeric complex composed of c-Fos and c-Jun/JunD phosphoproteins. While c-Fos is essential, JunD is dispensable for light-induced photoreceptor apoptosis. Here we show that N-terminal phosphorylation of c-Jun, the other main partner of c-Fos in induced AP-1 complexes is not required for programmed cell death during retinal development in vivo and is also dispensable for photoreceptor apoptosis induced by the exogenous stimuli "excessive light" and N-nitroso-N-methylurea (MNU). Mice expressing a mutant c-Jun protein (JunAA) that cannot be phosphorylated at its N-terminus are apoptosis competent and their retina is not distinguishable from wild-type mice. Accordingly, Jun kinase, responsible for phosphorylation of wild-type c-Jun protein is at best only marginally induced by the apoptotic stimuli "light" and MNU. Complex composition of light-induced AP-1 complexes is similar in wild-type and JunAA mice. This shows that the mutant c-Jun protein can be part of the DNA binding complex AP-1 and demonstrates that induction of the DNA binding activity of AP-1 after light insult does not depend on N-terminal phosphorylation of c-Jun. Our results suggest that transactivation of target genes by phosphorylated c-jun/AP-1 is not required for MNU- or light-induced apoptosis of photoreceptor cells.

Alkylating Agents↗

PubMed2001

Decision criteria and characteristics of Norwegian general dental practitioners selecting digital radiography.

OBJECTIVES: To evaluate Norwegian general dental practitioners' decision criteria and characteristics for choosing digital radiographic equipment. METHODS: A questionnaire was sent to all dental practitioners in Norway (n = 3940). They were categorised on the basis of their responses as either a 'digital radiography' (DR) or 'non-digital radiography' (non-DR) dentist. Demographic, clinical, and electronic technology variables were recorded. Dentists ranked on a six-point scale their reasons for choosing or not choosing digital radiography. Their responses were analysed by logistic regression. RESULTS: Two thousand, one hundred and ninety-nine dentists (56%) replied. Three hundred and nine (14%), (219 men, 86 women and four not stated) had chosen to use digital radiography. The logistic regression analysis revealed that gender, age and years in dentistry were not significant factors in determining their decision, whereas working in a private or group practice was. The number of computers in the practice was the most important of the electronic technology variables. The non-DR dentists strongly agreed that 'digital radiography is too expensive' and were 'satisfied with film'. The DR dentists strongly agreed that the 'use of chemicals can be avoided', 'patient dose is reduced', and 'archiving is facilitated'. CONCLUSION: Working in a private or group practice or using multiple computers were significant factors in choosing digital radiography.

Adult↗

PubMed2001

Experience of Norwegian general dental practitioners with solid state and storage phosphor detectors.

OBJECTIVES: To evaluate the opinions of Norwegian dental practitioners regarding the use of solid state sensor and storage phosphor (SP) detectors for intra-oral radiography. METHODS: A questionnaire received from 2199 dentists 309 (219 male, 86 female, four unknown) confirmed the use of digital radiography in their practices. RESULTS: Sixty-one per cent of dentists used a SP and 35% a sensor system; four (1.3%) used both. Approximately 50% of dentists had experienced technical problems and 33% had needed repairs. Almost all dentists stored their images on the hard disk (>97%) and 81% made a daily back-up. More sensor than SP users found difficulty with the positioning holder. Two-thirds of dentists reported digital image quality was the same or better than film. More Digora (Soredex, Helsinki, Finland) users reported better image quality than Denoptix (Gendex, Milan, Italy) or Digident (Digident, Nesher, Israel) users. Mean reduction in exposure time was 55% (range 2-90%), although 17 dentists stated that no reduction was achieved. Approximately half of the sensor users also used film and 38% of the SP users. Film was used more often for bitewing examination by the sensor users (27%) than by the SP users (4%). Mean time saved by the sensor users was 36 min/day (range 10-120) and by the SP users 25 min/day (range 5-120). CONCLUSIONS: The majority of dentists felt that digital image quality was the same or better than film and exposure and examination times were reduced. However, technical problems and repairs were common.

Compact Disks↗