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G C Sanderink

Publications and source records attributed to G C Sanderink.

At least 19 recordsLinked to original sources
PubMed2001

Organ radiation dose assessment for conventional spiral tomography: a human cadaver study.

The head of a human cadaver was positioned in a Cranex TOME multifunctional unit (Orion Corporation Soredex, Helsinki, Finland) to measure the organ radiation doses after tomographic examinations of the upper and lower edentulous jaw bone. Five consecutive examinations were carried out in the upper and lower anterior jaw regions to cover the entire frontal area, 2 in the upper and lower left premolar regions, and 3 and 4 in the upper and lower left molar regions, respectively. Each examination consisted of 4 slices with a 2 mm slice thickness. Thermoluminescent dosimeter chips were placed in the thyroid gland and bilaterally in the parotid and submandibular glands. Dosimetric measurements were repeated for the different tomographic examinations mentioned above. For spiral tomography in the maxilla, organ doses for both parotid glands were most elevated, while those for the thyroid glands were the lowest. Average doses per examination reached levels of 0.27 mGy for the right (OS) parotid gland with frontal tomography, and 3.89 mGy and 1.67 mGy for the parotid gland at tube-side (TS) for premolar and molar tomography. For the thyroid gland, a minimal dose of < or = 0.004 mGy was noticed for all examinations. For spiral tomography of the frontal area in the mandible, the OS parotid gland received the highest dose (0.77 mGy), while for an analysis of the premolar and molar areas, doses were more elevated for the TS parotid gland (1.22 mGy and 1.72 mGy, respectively). For the TS submandibular gland, organ doses were also raised, with values of 0.39 mGy for frontal, 1.31 mGy for premolar and 1.61 mGy for molar tomography. This study thus indicates that for conventional spiral tomographic examinations in the maxilla and the mandible, radiation doses for the TS submandibular and parotid glands were significantly more elevated than those to the thyroid gland. These values remain however below the organ doses previously reported for spiral CT involving both a full upper or lower jaw.

Aged↗
PubMed2001

Sensitometric and clinical evaluation of a new F-speed dental X-ray film.

OBJECTIVE: To compare the sensitometric properties, diagnostic efficacy and image quality of the InSight (F-speed) and Ektaspeed Plus (E-speed) dental X-ray films (Kodak Eastman Co, Rochester, USA). METHODS: Characteristic curves were constructed, using manual and automatic processing, in order to compare film speed and average gradient. The diagnostic yield was compared by assessment of endodontic file length. Endodontic files, sizes 10 and 15, were placed at the root apex or 1.5 mm short. The exposure time for the InSight films was 20% lower than that of Ektaspeed Plus. Seven dentists rated the position of file tip using a 5-point confidence scale. ROC data were analysed by means of analysis of variance. The null hypothesis was rejected when P<0.05. In order to compare the image quality, 100 pairs of bitewing radiographs of the left (using Ektaspeed Plus) and the right sides (using InSight) of the same patient were made. Four dentists viewed the radiographs and the data were analysed using Kendall's coefficient of concordance. RESULTS: InSight was faster than Ektaspeed Plus. It was an E-speed film when processed in manual conditions and an F-speed film when processed automatically. The films had comparable average gradient. No significant difference was found in the diagnostic yield using the two films (P=0.648). Two observers showed a significant preference for Ektaspeed Plus. CONCLUSIONS: The first results of the new InSight film are promising: the exposure time can be reduced by 20% in comparison with Ektaspeed Plus at no detriment to diagnostic efficacy.

Absorptiometry, Photon↗
PubMed2001

Comparative dose measurements by spiral tomography for preimplant diagnosis: the Scanora machine versus the Cranex Tome radiography unit.

Objective. The purpose of this study was to determine the dose profile of the Cranex Tome radiography unit and compare it with that of the Scanora machine. Study design. The radiation dose delivered by the Cranex Tome radiography unit during the cross-sectional mode was determined. Single tooth gaps in regions 3 (16) and 30 (46) were simulated. Dosimetry was carried out with 2 phantoms, a head and neck phantom and a full-body phantom loaded with 142 thermoluminescent dosimeters (TLD) and 280 TLD, respectively; all locations corresponded to radiosensitive organs or tissues. The recorded local mean organ doses were compared with those measured in another study evaluating the Scanora machine.Results. Generally, dose values from the Cranex Tome radiography unit reached only 50% to 60% of the values measured for the Scanora machine. The effective dose was calculated as 0.061 mSv and 0.04 mSv for tooth regions 3 (16) and 30 (46), respectively. Corresponding values for the Scanora machine were 0.117 mSv and 0.084 mSv.Conclusion. Cross-sectional imaging in the molar region of the upper and the lower jaw can be performed with the Cranex Tome unit, which delivers only approximately half of the dose that the Scanora machine delivers.

Anatomy, Cross-Sectional↗
PubMed2000

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

OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Analysis of Variance↗
PubMed2000

Intraoral detectors. CCD, CMOS, TFT, and other devices.

The first real-time intraoral detectors were introduced in 1997. Since then, charge-coupled device sensors have dramatically improved. The spatial and gray-scale resolution has increased and the dimensions of the sensitive areas are now comparable to those of conventional film. More recently, complementary metal oxide semiconductors were introduced. This technology offers the potential of integration, manufacturability, and low costs. Digital radiographic technology has matured and clinicians should adopt the systems and invest the time and effort to master them.

Costs and Cost Analysis↗
PubMed1999

Sensitometric evaluation of four dental X-ray films using five processing solutions.

OBJECTIVES: To compare the sensitometric properties of four dental films: Ektaspeed Plus and Ultra-speed (Kodak Eastman Co, Rochester, USA) and new and previous Dentus M2 (Agfa-Gevaert, Mortsel, Belgium) in five different processing solutions. METHODS: Characteristic curves were constructed for four dental X-ray films using five different processing solutions. All films were processed manually in three sets of chemicals for manual processing: Agfa (Heraeus Kulzer, Dormagen, Germany), Kodak (Kodak-Pathé, Paris, France) and Demat (Viscopac, Athens, Greece) and two sets of chemicals for automatic processing: Dürr XR and Periomat (Dürr Dental, Bietigheim-Bissingen, Germany). Analysis of variance and regression analysis was performed to examine the factors significantly affecting film density. RESULTS: The new Dentus M2 film had comparable gradient, higher speed and lower base-plus-fog than its predecessor. It had comparable speed with Ektaspeed Plus in chemicals for automatic processing. All films had a higher speed and lower gradient when processed in the chemicals for automatic processing. The highest film speed was achieved using Dürr XR chemicals. CONCLUSIONS: The new Agfa Dentus M2 film is an E-speed film and can be considered an alternative to Ektaspeed Plus: both can be recommended for use in dental practice as they contribute to dose reduction.

Absorptiometry, Photon↗
PubMed1999

Effects of developer exhaustion on the sensitometric properties of four dental films.

OBJECTIVES: To examine the effects of exhaustion of five different processing solutions on the sensitometric properties of four dental X-ray films: Ektaspeed Plus and Ultra-speed (Kodak Eastman Co. Rochester, USA) and new and previous Dentus M2 (Agfa-Gevaert, Mortsel, Belgium). METHODS: An aluminum stepwedge was used to construct characteristic curves for the four films. All films were processed manually using three sets of chemicals for manual processing: Agfa (Heraeus Kulzer, Dormagen, Germany), Kodak (Kodak-Pathé, Paris, France) and Demat (Viscopac, Athens, Greece) and two sets for automatic processing: Dürr XR and Periomat (Dürr Dental, Bietigheim-Bissingen, Germany). Film speed and gradient were evaluated until the chemicals were completely exhausted. An analysis of variance was performed separately for each set of chemicals for manual and automatic processing. RESULTS: Ektaspeed Plus was the fastest film in the manual processing solutions. The new Dentus M2 and Ektaspeed Plus films had similar speed using the chemicals for automatic processing. Ultra-speed had the lowest speed in all solutions, but it had the greatest consistency. Exhaustion of the developer caused a comparable decrease in speed of Ektaspeed Plus and the two Dentus M2 films. In fresh chemistry Agfa was the strongest manual processing solution, but it had the highest exhaustion rate. The Dürr XR chemical was stronger than Periomat over the whole test period. CONCLUSIONS: The combination of film and processing solution is an important factor for achieving constant sensitometric properties. Ektaspeed Plus and the new Dentus M2 film should be used in dental practice, as they require lower exposure and have equivalent or superior properties compared with Ultra-speed.

Analysis of Variance↗
PubMed1999

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

OBJECTIVES: To compare the diagnostic accuracy for the detection of approximal caries of three dental X-ray films using fresh and aged processing chemicals. METHODS: Fifty-six extracted unrestored premolars were radiographed under standardized conditions using the new Dentus M2 (Agfa-Gevaert, Mortsel, Belgium), Ektaspeed Plus and Ultra-speed (Kodak Eastman Co, Rochester, USA) dental films. The films were processed manually using Agfa chemicals (Heraeus Kulzer, Dormagen, Germany). The procedure was repeated once a week until the complete exhaustion of the chemicals (6 weeks). Three independent observers assessed 210 radiographs using the following rating scale: 0 = sound, 1 = enamel lesion; 2 = lesion reaching the ADJ; 3 = dentinal lesion. True caries depth was determined by histological examination (14 sound surfaces, 11 enamel lesions, eight lesions reaching the ADJ and 23 dentinal lesions). 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. RESULTS: No significant differences were found in the diagnostic accuracy between the three films when using chemicals of up to 3 weeks old (P = 0.056). After the third week, Ultra-speed was significantly better than the other two films (P = 0.012). On average caries depth was underestimated. CONCLUSION: A similar level of diagnostic accuracy for approximal caries is achieved when using the three films. Dentus M2 and Ektaspeed Plus are at present the fastest available films and they should therefore be recommended for clinical practice. Agfa chemicals should be renewed every 3 weeks. Fifty per cent reduction in average gradient is indicative of renewing processing chemicals.

Analysis of Variance↗
PubMed1999

The effects of developer age on diagnostic accuracy: a study using assessment of endodontic file length.

OBJECTIVES: To examine the effects of developer age on image quality. METHODS: Endodontic files, size 10 and 15, were placed in upper and lower molars and premolars up to the root apex or 1.5 mm short. A series of radiographs were made with each of three film types: Dentus M2 (Agfa-Gevaert, Mortsel, Belgium), Ektaspeed Plus and Ultra-speed (Kodak Eastman Co, Rochester, USA). The films were processed bi-weekly using the same Agfa chemicals (Heraeus Kulzer, Dormagen, Germany) over a 6-week period. An additional set of Dentus M2 films was processed using Periomat chemicals (Dürr Dental, Bietigheim-Bissingen, Germany). The films were viewed by eight dentists who rated the position of the tip of the file using a 5-point confidence scale. ROC data were analysed by means of analysis of variance. Az value was the dependent variable, whereas observer age group was entered as between subject factor. The null hypothesis was rejected when P<0.05. RESULTS: The diagnostic accuracies of the three films were comparable during the first 4 weeks. In the sixth week Ultra-speed was significantly better than the other two films (P=0.046). The Periomat chemicals showed significantly greater consistency than the Agfa chemicals (P=0.004). Developer exhaustion significantly affected the performance of the older observers (P=0.008), especially when Agfa chemicals and file size 10 were used. CONCLUSION: Agfa chemicals older than 4 weeks significantly affect the assessment of endodontic file length. In earlier stages there are no significant differences between the three films tested. Dentus M2 and Ektaspeed Plus films should be used as they require lower exposures.

Adult↗
PubMed1998

Radiographic evaluation of apical root resorption with 2 different types of edgewise appliances. Results of a randomized clinical trial.

The purpose of this paper was to compare radiographically the prevalence and degree of apical root resorption after treatment with a fully programmed edgewise appliance (FPA) and a partly programmed edgewise appliance (PPA) in a randomized multipractice clinical trial. Two groups of patients with Class II malocclusions were treated orthodontically. The type of treatment was randomly assigned by a computer program. During fixed appliance therapy, one group was treated according to the precepts of the straight wire concept (FPA; n = 32) while the other was treated with conventional full edgewise mechanics (PPA; n = 29). Treatment times were recorded. Radiographs of the maxillary incisors were made before and after active treatment with fixed appliances using the bisecting angle technique. To correct for different projecting angles the pairs of radiographs were digitally reconstructed. The prevalence and degree of root resorption were assessed. The mean treatment time was 1.8 years and 1.6 years for treatment with FPA and PPA, respectively. The mean amount of loss of tooth length was 8.2% for the patients treated with FPA and 7.5% for the patients treated with PPA. No statistically significant differences could be assessed between both groups at the end of active treatment. The mean prevalence of apical root resorption was 75% for the patients treated with FPA and 55% for the patients treated with PPA. Statistical evaluation showed no significant differences. We concluded that the prevalence and degree of root resorption is independent of the appliances as used in this study.

Adolescent↗
PubMed1998

Reduction in size of digital images: does it lead to less detectability or loss of diagnostic information? .

OBJECTIVES: To analyse the effect of reduction in size of digital images on diagnostic outcome. METHODS: A series of 100 Visualix III (Gendex Dental Systems, Milano, Italy; Dentsply, Des Plaines, IL, USA) images was made of size 10 and 15 endodontic files in upper and lower (pre)molars. Three forms of image were created: (a) the original images, (b) reduced to one-half (containing one-quarter of the information of the original, and (c) zoomed-in, half-size images (magnification 2:1; original image size but with only one-quarter of the original information). Seven radiologists were asked to rate the position of the tip of the file, using a five-point confidence scale. ROC data were analysed by means of MANOVA statistics. RESULTS: A significant difference was found between the three image modalities for both size 10 (P < 0.005), and size 15 (P < 0.021) files. CONCLUSIONS: Reduction in size of digital images may cause less detectability as well as loss of diagnostic information.

Computer Peripherals↗
PubMed1998

An evaluation of periapical radiography with a charge-coupled device.

OBJECTIVES: To compare the standards of periapical radiography with a CCD-image receptor with film. METHODS: Three radiography technicians exposed a total of fifty teeth from all areas of the jaws using either size 1 or size 2 film and the Sidexis (Siemens, Bensheim, Germany) direct digital dental radiography system with the appropriate film holders. Image quality was assessed by two dental radiologists for nine individual criteria and overall, on a three-point scale. RESULTS: There was a significant difference between film and sensor exposures (P < 0.014). Six per cent of dental films required retakes compared with 28% with the sensor. CONCLUSION: Periapical radiography with a CCD sensor leads to more errors and thus more retakes than conventional film.

Evaluation Studies as Topic↗
PubMed1998

Effects of calibration and automatic greyscale adjustment on detectability of simulated bone lesions using a storage phosphor system.

OBJECTIVES: To analyse the interaction of calibration, automatic greyscale adjustment and X-ray exposure on the evaluation of simulated bone lesions with the Digora (Orion Corporation Soredex, Helsinki, Finland) storage phosphor system. METHODS: Exposures were made under five conditions based on the exposure time for Ektaspeed Plus film: A-calibration exposure 100%, exposure 100%; B-calibration exposure 100%, exposure 50%; C-calibration exposure 100%, exposure 10%; D-calibration exposure 50%, exposure 50%; E-calibration exposure 10%, exposure 10%. Series of images of artificial bone lesions were created each representing one of the five conditions, with or without automatic greyscale adjustment and including one of two lesion sizes. The series were evaluated by seven expert radiologists. Results were analysed by means of MANOVA statistics. RESULTS: The large lesions were evaluated significantly better than the small lesions (P < 0.011). The two 10% exposure conditions were evaluated significantly worse than the other three (P < 0.029) which had comparable results. Automatic greyscale adjustment had no significant effect (P > 0.253). CONCLUSIONS: The Digora should be calibrated for the highest exposure to be used to optimize the wide latitude. Automatic greyscale adjustment is not useful for the detection of simulated bone lesions.

Bone Diseases↗
PubMed1997

In vivo study of approximal caries depth on storage phosphor plate images compared with dental x-ray film.

The aim of this in vivo study was to compare approximal caries depth on storage phosphor plate images to conventional film. A Soredex Digora imaging plate was placed in a film bite-wing positioner behind a Kodak Ektaspeed Plus film package without lead foil. The effect of scattered radiation on film without lead foil with a storage phosphor plate at the back was studied in a separate in vitro experiment. Compared with film protected by lead foil, the film showed higher density, but comparable contrast. For the in vivo study, clinical bite-wing exposures were made with the setup described above, with exposure settings for Ektaspeed Plus film. A four-point scale was chosen for approximal caries depth: 0 = no caries; 1 = caries in enamel; 2 = caries reaching dentino-enamel junction; 3 = caries into dentin. The bite-wing film images were shown to a panel of four experts. Sixty surfaces were selected for observer performance, based on identical scorings of the experts consensus classification. Next, six dentists evaluated both film and storage phosphor plate images with the same four point scale. Analysis of variance revealed a significant observer and image modality effect without an interaction effect. In conclusion, caries depth on storage phosphor plate images was underestimated compared with film-based images.

Dental Caries↗
PubMed1997

Impact of scale standardization on images of digital radiography systems.

OBJECTIVES: To test the effect of altering image size on diagnostic quality. METHODS: Endodontic files, size 10 and 15 were prepared to full root length and 1.5 mm short, in upper and lower molars and premolars. Digital images of the Sidexis (S) and Visualix/Vixa (V) system were reduced in size to Digora (D) scale, and the D images were enlarged to S scale. ROC analysis was performed and data analysed with MANOVA statistics. RESULTS: Assessment of root canal length with file size 10 was less accurate for the S images reduced in size, compared with the original S images (P < 0.011). All other differences were not significant (P > 0.081). CONCLUSIONS: Relevant diagnostic information may be lost when images are reduced in size. Therefore, for optimal presentation, the smaller images should be enlarged rather than the larger ones reduced.

Analysis of Variance↗
PubMed1997

Estimating distances on direct digital images and conventional radiographs.

Digital images produced by direct sensor systems are much larger than conventional radiographic film images because of monitor resolution and digital image file sizes. This difference in size may introduce difficulties when estimating distances (for example, during endodontic treatment). The aim of this study was to compare observers' estimates of distances on digital images with those of conventional radiographs.

Dental Pulp Cavity↗