Audit of a 5-year radiographic protocol for assessment of mandibular third molars before surgical intervention.

OBJECTIVES: To perform an audit of a three-step protocol for radiographic examination of mandibular third molars before surgery. METHODS: 1769 teeth underwent surgery. A standardized three-step radiographic protocol was followed: (1) panoramic imaging (PAN), (2) stereoscanography (SCAN) and (3) CBCT. If there was overprojection between the tooth and the canal in PAN, SCAN was performed. If the tooth was determined to be in close contact with the canal in SCAN, CBCT was performed. Close contact between the tooth and the canal was assessed in all images, and patient-reported sensory disturbances from the alveolar inferior nerve were recorded after surgery. The relation between the final radiographic examination and sensory disturbances was determined. Logistic regression analysis tested whether signs for a close contact in PAN/SCAN could predict no bony separation between the tooth and canal in CBCT. RESULTS: 46% of teeth underwent PAN, 31% underwent SCAN and 23% underwent CBCT as the final examination. 21% underwent all three radiographic examinations. 53/76% of teeth with close relation to the canal in PAN/SCAN showed no bony separation in CBCT; if there was close relation in PAN/SCAN, there was 1.6/4.3 times higher probability that no bony separation existed in CBCT. 16 cases of sensory disturbances were recorded: 4 operations were based on PAN, 8 on SCAN and 4 on CBCT. CONCLUSIONS: The radiographic protocol was in general followed. SCAN was superior to PAN in predicting no bony separation between the tooth and the canal in CBCT, and there was no relation between sensory disturbances and radiographic method.

Reproducibility of mandibular third molar assessment comparing two cone beam CT units in a matched pairs design.

The aim of this study was to evaluate the reproducibility of the third molar assessment, comparing five observers and two cone beam CT (CBCT) units. 28 patients, each with two impacted mandibular third molars, were included. Each patient was randomly examined with a Scanora(®) 3D (Soredex, Helsinki, Finland) CBCT unit in one mandibular third molar region and with a Cranex(®) 3D (Soredex) CBCT unit in the other region. Five observers with varying CBCT experience assessed all third molars and recorded the following variables: number and morphology of the roots, relation to the mandibular canal in two directions, shape of the canal and whether there was a direct contact between the roots of the molar and the mandibular canal. The radiographic assessments were compared pairwise among all observers for all variables. Wilcoxon's signed-rank test was used to test the differences in observer accordance percentages among the recorded variables in the images from the two units, and kappa statistics expressed interobserver reproducibility. The mean percentages for observer accordance ranged from 65.4 to 92.9 for Scanora 3D and 60.3 to 94.8 for Cranex 3D. There was no significant difference between the observer accordance in the two CBCT units (p > 0.05), except for assessing root flex in the mesiodistal direction, for which the observer accordance was higher for Scanora 3D (p < 0.05). Kappa values ranged from 0.1 to 1.0 for Scanora 3D and from 0.2 to 0.9 for Cranex 3D. For the variable "direct contact", the interobserver reproducibility was excellent for the two trained radiologists. The two units had almost similar interobserver reproducibility for mandibular third molar assessment. Observer variation existed, and experienced radiologists demonstrated the highest interobserver reproducibility for canal-related variables.

Influence of cone beam CT on treatment plan before surgical intervention of mandibular third molars and impact of radiographic factors on deciding on coronectomy vs surgical removal.

OBJECTIVES: To assess the influence of cone beam CT (CBCT) on treatment plan before surgical intervention of mandibular third molars and to identify radiographic factors with an impact on deciding on coronectomy. METHODS: 186 mandibular third molars with an indication for surgical intervention underwent a radiographic examination with two methods: (1) panoramic imaging in combination with stereo-scanography and (2) CBCT. After the radiographic examination a treatment plan (TP) was established: either surgical removal (Sr) or coronectomy (Co). The first TP was based on the panoramic image and stereo-scanogram, while the second TP was established after CBCT was available. Logistic regression analyses were used to identify factors predisposing for Co after CBCT. RESULTS: Treatment was performed according to the second TP. Agreement between the first and second TP was seen in 164 cases (88%), while the TP changed for 22 teeth (12%) after CBCT. Direct contact between the third molar and the mandibular canal had the highest impact on deciding on Co [odds ratio (OR) = 101.8, p < 0.001]. Direct contact was not a sufficient factor, however; thus, lumen narrowing of the canal (OR = 38.9-147.2, p < 0.001) and canal positioned in a bending or a groove in the root complex (OR = 32.8, p = 0.016) were additional canal-related factors for deciding on Co. CONCLUSION: CBCT influenced the treatment plan for 12%. Direct contact in combination with narrowing of the canal lumen and canal positioned in a bending or a groove in the root complex observed in CBCT images were significant factors for deciding on coronectomy.

Periapical and endodontic status of permanent teeth in patients with hypophosphatemic rickets.

Hypophosphatemic rickets (HR) is a rare hereditary disease in which dental problems in terms of spontaneous periapical infections are frequently reported. Most previous reports have been based on a small number of HR patients and have been published before the disease could be confirmed genetically. The aim of the present study was to describe the periapical and endodontic status of permanent teeth in patients with genetically and/or biochemically confirmed HR. The patients were recruited from a medical study on HR patients. The patients underwent a dental examination including a digital panoramic radiograph, which was scored for endodontically affected teeth (i.e. teeth with periapical radiolucencies and/or endodontically treated teeth). A total of 52 patients (age range: 5·7-74·5 years; 17 males and 35 females) were included. HR patients were characterised by a high number of endodontically affected teeth (mean: 4·2; s.d.: 5·0). The number of affected teeth rose significantly with age (P < 0·01), and no statistically significant gender difference was found. The relative distribution of endodontically affected teeth in the three tooth groups (incisors and canines, premolars, and molars) varied according to age. In the youngest age group, only incisors and canines were affected, while the relative proportion of affected premolars and molars increased with age. Endodontically affected teeth are common in HR patients, and the number of affected teeth increased significantly with age. Hence, the need for endodontic treatment among HR patients is comprehensive.

Effect of monitor display on detection of approximal caries lesions in digital radiographs.

OBJECTIVES: The aim was to compare the accuracy of five flat panel monitors for detection of approximal caries lesions. METHODS: Five flat panel monitors, Mermaid Ventura (15 inch, colour flat panel, 1024 x 768, 32 bit, analogue), Olórin VistaLine (19 inch, colour, 1280 x 1024, 32 bit, digital), Samsung SyncMaster 203B (20 inch, colour, 1024 x 768, 32 bit, analogue), Totoku ME251i (21 inch, greyscale, 1400 x 1024, 32 bit, digital) and Eizo FlexScan MX190 (19 inch, colour, 1280 x 1024, 32 bit, digital), were assessed. 160 approximal surfaces of human teeth were examined with a storage phosphor plate system (Digora FMX, Soredex) and assessed by seven observers for the presence of caries lesions. Microscopy of the teeth served as validation for the presence/absence of a lesion. RESULTS: The sensitivities varied between observers (range 7-25%) but the variation between the monitors was not large. The Samsung monitor obtained a significantly higher sensitivity than the Mermaid and Olórin monitors (P<0.02) and a lower specificity than the Eizo and Totoku monitors (P<0.05). There were no significant differences between any other monitors. The percentage of correct scores was highest for the Eizo monitor and significantly higher than for the Mermaid and Olórin monitors (P<0.03). CONCLUSIONS: There was no clear relationship between the diagnostic accuracy and the resolution or price of the monitor. The Eizo monitor was associated with the overall highest percentage of correct scores. The standard analogue flat panel monitor, Samsung, had higher sensitivity and lower specificity than some of the other monitors, but did not differ in overall accuracy for detection of carious lesions.

Comparison of three radiographic methods for detection of morphological temporomandibular joint changes: panoramic, scanographic and tomographic examination.

OBJECTIVES: To compare the diagnostic accuracy of panoramic, scano- and tomographic examination for the detection of morphological temporomandibular joint (TMJ) changes. METHODS: TMJs in 80 dry human skulls were radiographed using digital panoramic examination, 4x sagittal (lateral) scanography, and sagittal cross-sectional tomography. All images were examined by three independent observers for the presence or absence of flattening, defects and osteophytes in the various joint components. The true presence of the morphological changes was unanimously decided by consensus of three independent observers using naked-eye inspection. The accuracy for detection of the specific changes in each joint component was expressed as sensitivity and specificity values, whereas the accuracy for detection of morphological changes in general in the condyle and in the TMJ in toto was expressed as the number of matching radiographic and "gold standard" scores. RESULTS: Up to 23% and 9% of the three joint components were recorded as non-accessible to examination with panoramic examination and sagittal (lateral) scanography, respectively, whereas all components were accessible to examination with sagittal cross-sectional tomography. The difference was significant between panoramic examination and sagittal cross-sectional tomography (P = 0.018). No significant differences between the three methods for detection of specific morphological changes in the condyles and defects in the articular tubercles and changes in the TMJ in toto were found. CONCLUSION: No differences in accuracies between the methods were found for the detection of morphological TMJ changes. However, with panoramic examination and sagittal (lateral) scanography markedly more joint components were non-accessible to examination than with sagittal cross-sectional tomography, with which all components were accessible.

Cone beam CT and conventional tomography for the detection of morphological temporomandibular joint changes.

OBJECTIVE: To compare the diagnostic accuracy of cone beam CT images with conventional tomographic images for the detection of morphological temporomandibular joint (TMJ) changes. METHODS: 80 dry human skulls were scanned using a NewTom 3G scanner and lateral and frontal reconstructions of the right and the left TMJs were performed. In addition, lateral and frontal cross-sectional tomograms of the skulls' TMJs were obtained in a Cranex Tome unit with Digora storage phosphor plates. Naked-eye inspection of the TMJs performed by three observers served as the gold standard for the true presence of morphological changes. The mandibular fossae were excluded from the study due to few changes in this joint component. The NewTom and the conventional tomographic images were examined by three independent observers using a binary scale for the presence of morphological changes in the condyle (flattening, defects and osteophytes) and the articular tubercle (flattening and defects). The accuracy for the different types of changes in relation to the condyles and the articular tubercles was expressed as sensitivity and specificity values, whereas the diagnostic accuracy for a general assessment including all changes in both joint components was expressed by the sum of cases where the gold standard and the radiographic scores were not identical (absolute difference). Differences between the two radiographic modalities were tested by paired t-test. RESULTS: Detection of the various types of morphological changes in relation to the condyle and the articular tubercle assessed separately resulted in no significant differences between the two radiographic modalities, with the exception of bone defects in the articular tubercle examined on frontal views alone where the specificity with tomography was significantly higher than with cone beam CT. Detection of all morphological changes in relation to both the condyle and the articular tubercle showed a significantly higher accuracy with tomography than with cone beam CT using lateral views alone, but there was no significant difference between the two modalities using frontal views alone and lateral and frontal views in combination. CONCLUSION: In general, no significant differences in diagnostic accuracy for the detection of bone changes in the condyle and in the articular tubercle were found between cone beam CT images and conventional tomograms.

Comparison of diagnostic accuracy of film and digital tomograms for assessment of morphological changes in the TMJ.

OBJECTIVE: To compare diagnostic accuracy of tomograms obtained with film and three digital image receptor modalities for detection of morphological changes in the temporomandibular joint (TMJ). METHODS: Lateral and frontal cross-sectional tomograms of 158 TMJs in 80 dry human skulls were obtained with four X-ray receptors: one conventional film (Agfa-Gevaert), two photostimulable phosphor (PSP) plates: VistaScan and Digora PCT and one charge-coupled device (CCD): ProMax. The film and the PSP plate tomograms were exposed in a Cranex Tome X-ray unit and the CCD tomograms in the ProMax X-ray unit. The tomograms were examined by three observers for the presence of morphological changes in the condyle, the mandibular fossa and the articular tubercle. Naked-eye inspection of the articular surfaces of the TMJs performed by the same three observers served as the gold standard for the true presence of morphological changes. RESULTS: For examination of TMJ changes using lateral and frontal tomograms in combination and lateral tomograms separately, the ProMax modality obtained a significant lower diagnostic accuracy than the other three modalities, between which no significant differences were found. For morphological changes localized to the condyle in which the highest number of changes were present according to the gold standard, the same result was found. CONCLUSION: The ProMax modality was significantly less accurate than the film, VistaScan and Digora PCT modalities for the detection of overall TMJ morphological bone changes as well as condylar bone changes.

Diagnostic accuracy of two software modalities for detection of caries lesions in digital radiographs from four dental systems.

OBJECTIVE: To compare the caries diagnostic accuracy of two software modalities used in the assessment of digital radiographs obtained with four different dental systems, and to evaluate whether the software used for image assessment influenced the mutual comparison of those four dental systems relating to their caries diagnostic accuracy. METHODS: Under in vitro and standardized conditions 122 teeth (with 228 unrestored approximal and 99 occlusal surfaces) were radiographed in blocks of 3 test teeth and 2 non-test teeth using two storage phosphor plate systems: Digora (Soredex, Helsinki, Finland) and DenOptix (Gendex, Dentsply, Milan, Italy) and two charge coupled device (CCD)-based sensor systems: Dixi (Planmeca, Helsinki, Finland) and Sidexis (Sirona, Bensheim, Germany). The images were displayed and examined in two software modalities: their own dedicated software and a general software. Three observers examined all images for the presence of approximal enamel and dentine and occlusal dentine caries lesions using a 5-point confidence scale. The true presence of caries was validated by ground section histology. The diagnostic accuracy of the software modalities was expressed as ROC curve areas (A(z)) and differences between modalities were tested by paired t-test. Comparison of systems was analysed by post hoc t-test. RESULTS: Results of approximal and occlusal surfaces assessed together revealed nearly identical mean A(z) with the two software modalities on images obtained with the Digora (A(z)=0.71) and DenOptix (A(z)=0.72) systems. On Dixi images the mean A(z) was 0.75 using the system's own software and 0.73 using the general software. On Sidexis images the corresponding mean A(z)s were 0.79 and 0.75. None of those differences were significant. CONCLUSION: No significant difference in caries diagnostic accuracy was found between two software modalities used for examination of digital radiographs obtained with four different digital systems, and the software modality did not influence the mutual rank of the four systems relating to their diagnostic accuracy.

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.

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.

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.

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.

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

Approximal caries prevalence in Danish recruits and progression of caries in the late teens: a retrospective radiographic study.

This study aimed to assess radiographically the prevalence and distribution of approximal caries in Danish recruits and to estimate the rate of caries progression during the recruits' late teens. To assess caries progression radiographs taken previously (when leaving the Public Dental Health Care Service, usually at the age of 16-18) were requested. Of 676 recruits previous radiographs (taken 1-7 years earlier) were procured for 640. Approximal surfaces from 7d to 4m in the maxilla and the mandible were assessed for the absence or presence/depth of caries and restorations. Caries progression was expressed by the incidence rate indicating the number of new lesions/number of lesions with progression per 100 years. In the maxilla the average prevalence of enamel and dentine caries was 8.3 and 6.2%, respectively. Overall, 6m had the highest caries experience. In the mandible the average prevalence of enamel and dentine caries was 10.7 and 5.8%, respectively. The highest caries experience was found in 6d. Twenty percent of the recruits had no caries experience in the surfaces under study, 9% had caries experience in 1 surface, 13% in 4-5 surfaces and 25% in more than 10 surfaces. For all surfaces combined, the median incidence rate for the transition from sound to enamel caries was 2.4 surfaces per 100 years, ranging from 0.4 in mandibular 7d to 5.5 in mandibular 6d. The median rate for progression from the enamel to the outer half of the dentine was 9.2 surfaces per 100 years, ranging from 4.4 in mandibular 5m to 18.9 in mandibular 6d. The median incidence rate for progression from the outer to the inner half of the dentine was 2.3 surfaces per 100 years. However, this figure was based on a small number of events and should therefore be interpreted with caution. In conclusion, enamel and dentine caries was found in 9 and 6% of the approximal surfaces in newly called up recruits, and one quarter of the recruits had caries experience in more than 10 approximal surfaces. Generally, the development of new approximal lesions and the progression of enamel caries was a slow process during the late teens.

Behaviour of approximal carious lesions assessed by clinical examination after tooth separation and radiography: a 2.5-year longitudinal study in young adults.

This study aimed to record and monitor over a 2.5-year period the occurrence of cavitation and lesion depth progression in approximal surfaces with radiographic caries at baseline. In total, 66 approximal sites (in 29 students), where at least one of the contacting surfaces had radiographic caries, were selected to take part in the study. A clinical examination undertaken before and after tooth separation in order to assess the presence/absence of cavitation was repeated every sixth month. To monitor lesion progression bite-wing radiographs were taken every sixth month, too. After each series of examinations, surfaces judged to be prone for disease progression were referred to operative caries treatment. In surfaces with radiographic dentinal caries at baseline the cavitation prevalence following tooth separation found at the various recall examinations ranged from 20 to 44%. In surfaces with radiographic enamel caries at baseline this prevalence ranged from 4 to 8% at the various recall examinations. In dentinal lesions found with an intact surface at baseline, the risk of cavitation development during the first 1.5-year period was assessed to be up to 22%. After this period no new cavitations were found in previously intact dentinal lesions. In intact enamel lesions the risk of cavitation formation was found to be 3% during the first 1-year period. After this period no new cavitations developed in previously intact enamel lesions. Three of 7 lesions, which showed radiographic caries progression from the outer one third to the inner two thirds of the dentine during the observation period, had intact surfaces at baseline. On the basis of these results it is recommended to re-examine carefully intact, dentinal lesions by repeated clinical examination after tooth separation and by radiography about 1-1.5 years after baseline.

A two-film versus a four-film bite-wing examination for caries diagnosis in adults.

The aim of this study was to compare the caries diagnostic outcome of a two-film and a four-film routine bite-wing examination undertaken in an adult population. A digital bite-wing examination using two and four films, respectively, was performed in 174 patients. The radiographs from the two examinations were assessed jointly by 2 observers for the number of imaged surfaces in the area from the distal surface of the canine to the distal surface of the third molar and for the detection of carious lesions. Significantly more surfaces were available for examination by the four-film than by the two-film examination. Overlapping surfaces were recorded in 14 and 10%, respectively, of the surfaces imaged by the two-film and four-film set. The prevalence of primary enamel and dentinal caries was 6.8% with the two-film and 5.6% with the four-film method. In 1, 684 surfaces only imaged by the four-film method caries was detected in 20 surfaces. If these extra lesions were added to the number of lesions found by the two-film method the total disease prevalence using the last-mentioned method would increase by 2 per thousand. The majority (92-99%) of all recorded lesions were detected in surfaces located between the occlusal surface of the first premolar and the mesial surface of the third molar. The little additional diagnostic outcome obtained by the use of four instead of two films did not seem to match the extra resources (double patient charge and radiation dose, and extended scan/developing and recording time for the dentist) connected to the four-film method. Thus, it may be recommended that a routine bite-wing examination undertaken in young adults should be performed with only two films: one in each side of the mouth, placed behind the premolars and the first and second molars.

Patient discomfort and cross-infection control in bitewing examination with a storage phosphor plate and a CCD-based sensor.

OBJECTIVES: The aim was to compare a CCD-based sensor and a storage phosphor plate with respect to patient discomfort and the efficacy of a simple cross-infection control procedure in connection with a posterior bitewing examination. METHODS: 130 patients accepted to have one posterior bitewing of the left and right side taken with two digital radiography systems, the Digora phosphor plate and the Trophy RVG XL, CCD-based sensor system. The patients assessed their feeling of discomfort after the examination on a 100-mm. Visual Analogue Scale (VAS). Microbiological samples were taken from the RVG sensor and cord and from the Digora envelope, plate and scanner during examination of 14 patients. The samples were plated and incubated anaerobically, and the colony-forming units counted. RESULTS: Median VAS score for discomfort was 20 min for Digora and 32 min for the RVG sensor (P < 0.001). Median total counts of cultivable bacteria were low (< 20), the majority being catalase-positive, Gram-positive cocci and Gram-positive rods, presumably skin bacteria. Only the samples taken from the enveloped Digora plate and the rubber tube coated RVG sensor immediately after exposure yielded large numbers of oral bacteria. CONCLUSION: The phosphor plate was less unpleasant than the CCD sensor. Cross-contamination posed a minor problem for both systems when a simple, standard hygiene procedure was followed.

Comparison of microscopy and radiography as gold standards in radiographic caries diagnosis.

OBJECTIVES: To compare the effect of the choice of gold standard on the diagnostic outcome of approximal caries detection in original and compressed digital radiographs. METHODS: 116 extracted teeth radiographed with a storage phosphor system constituted the original images. These images were compressed at 1:20 and 1:33 with the JPEG irreversible compression standard. Five radiologists scored the three sets of images for the presence of approximal caries on a five-rank confidence scale. The radiographic scores were validated by stereomicroscopy (the true gold standard). The individual ROC areas for the five observers were used to select the worst (obsworst) and the best (obsbest) performer: Their scores in the original images were used as the second and third 'gold standards' for the remaining observers. Mean ROC areas for the three observers with the three types of images were calculated using these two new 'gold standards'. Differences between the ROC areas when using microscopy, obsworst, and obsbest as the 'gold standard' were compared. RESULTS: The mean ROC areas in the original images were 0.66, 0.74 and 0.91 using the true gold standard and obsbest and obsworst as the 'gold standards' respectively. The difference between the true gold standard and obsworst was statistically significant (P < 0.001). The mean ROC areas using the true gold standard decreased with increasing compression whereas they were constant or increased using obsworst and obsbest as 'gold standards', respectively. CONCLUSIONS: Accuracy in approximal caries diagnosis was significantly higher when an observer was the 'gold standard' than when the true gold standard was obtained by microscopy. Paradoxically, the compressed, degraded images were more accurate than the originals when an observer was the 'gold standard' while they were less accurate with the true gold standard. Thus, results obtained using observers' scores from the radiographs which are being evaluated, as validation for the presence of caries may mislead the clinician.