Comparison of complementary metal oxide semiconductor and charge-coupled device intraoral X-ray detectors using subjective image quality

Artificial Intelligence through Wireless Sensors Applied in Restorative Dentistry: A Systematic Review

The integration of wireless sensors with artificial intelligence could represent a transformative approach in restorative dentistry, offering a sophisticated means to enhance diagnostic precision, treatment planning, and patient outcomes. This systematic review was conducted to pinpoint and assess the efficacy of wireless sensors in restorative dentistry. The search methodology followed the guidelines outlined by PRISMA and involved the utilization of prominent scientific databases. Following the final phase of evaluating eligibility, the systematic review included six papers. Five experiments were conducted in vitro, while one was a randomized clinical trial. The investigations focused on wireless sensors for cavity diagnosis, toothbrush forces, facial mask applications, and physiological parameter detection from dental implants. All wireless sensors demonstrated efficacy in achieving the objectives established by each study and showed the validity, accuracy, and reproducibility of this device. The investigations examined in this systematic review illustrate the potential of wireless sensors in restorative dentistry, especially in the areas of caries detection, dental implant systems, face masks, and power brushes. These technologies hold promise for enhancing patient outcomes and alleviating the workload of dental practitioners.

Performance of Oral Cavity Sensors: A Systematic Review

Technological advancements are enabling new applications within biomedical engineering. As a connection point between the outer environment and the human system, the oral cavity offers unique opportunities for sensing technologies. This paper systematically reviews the performance of measurement systems tested in the human oral cavity. Performance was defined by metrics related to accuracy and agreement estimation. A comprehensive search identifying human studies that reported on the accuracy or agreement of intraoral sensors found 85 research papers. Most of the literature (62%) was in dentistry, followed by neurology (21%), and physical medicine and rehabilitation (12%). The remaining papers were on internal medicine, obstetrics, and aerospace medicine. Most of the studies applied force or pressure sensors (32%), while optical and image sensors were applied most widely across fields. The main challenges for future adoption include the lack of large human trials, the maturity of emerging technologies (e.g., biochemical sensors), and the absence of standardization of evaluation in specific fields. New research should aim to employ robust performance metrics to evaluate their systems and incorporate real-world evidence as part of the evaluation process. Oral cavity sensors offer the potential for applications in healthcare and wellbeing, but for many technologies, more research is needed.

Characteristics of radiographic images acquired with CdTe, CCD and CMOS detectors in skull radiography

Purpose

The purpose of this study was to evaluate the image quality, diagnostic efficacy, and radiation dose associated with the use of a cadmium telluride (CdTe) detector, compared to charge-coupled device (CCD) and complementary metal oxide semiconductor (CMOS) detectors.

Materials and Methods

Lateral cephalographs of a phantom (type 1) composed of synthetic polymer filled with water and another phantom (type 2) composed of human skull macerated with polymer coating were obtained with CdTe, CCD, and CMOS detectors. Dosimeters placed on the type 2 phantom were used to measure radiation. Noise levels from each image were also measured. McNamara cephalometric analysis was conducted, the dentoskeletal configurations were assessed, and a subjective evaluation of image quality was conducted. Parametric data were compared via 1-way analysis of variance with the Tukey post-hoc test, with a significance level of 5%. Subjective image quality and dentoskeletal configuration were described qualitatively.

Results

A statistically significant difference was found among the images obtained with the 3 detectors (P<0.05), with the lowest noise level observed among the images obtained with the CdTe detector and a higher subjective preference demonstrated for those images. For the cephalometric analyses, no significant difference (P>0.05) was observed, and perfect agreement was seen with regard to the classifications obtained from the images acquired using the 3 detectors. The radiation dose associated with the CMOS detector was higher than the doses associated with the CCD (P<0.05) and CdTe detectors (P<0.05).

Conclusion

Considering the evaluated parameters, the CdTe detector is recommended for use in clinical practice.

Comparison of 2- and 3-dimensional radiologic evaluation of secondary alveolar bone grafting of clefts: a systematic review

OBJECTIVE

Secondary alveolar bone grafting (SABG) has become the principal means of treating alveolar cleft defects. We reviewed the literature on 2-dimensional (2-D) and 3-dimensional (3-D) radiographic evaluation of SABG in patients with cleft lip and alveolus (CLA) and those with cleft lip and palate (CLP), with a focus on outcomes.

STUDY DESIGN

We searched several electronic databases to the end of 2018. The inclusion criteria were nonsyndromic CLA or CLP treated with SABG at an optimal age and evaluation performed no earlier than 3 months postoperatively. Study quality was evaluated by using the Methodological Index for Non-Randomized Studies and the Cochrane Collaboration tool.

RESULTS

We identified 282 articles from 3 databases. Full texts of 102 articles were analyzed, and finally 11 articles were included for qualitative analysis. 2-D and 3-D radiographic evaluations were performed in each study. Traditional 2-D radiographic imaging tended to overestimate success; bone resorption in the labiopalatal direction was inaccurate in 2-D views. Most articles were observational in nature and of moderate methodologic quality.

CONCLUSIONS

2-D evaluation tended to overestimate SABG outcomes; 3-D evaluation was more precise and reliable than 2-D radiography. A gold standard 3-D evaluation protocol is required for quantitative comparisons in the future.

Effect of different exposure times on caries detection and pixel value in a wireless digital system

Objectives

: The aim of this study was to assess, using the CDR Wireless®, the effect of different exposure times on caries detection and pixel intensity values.

Materials and Methods

Forty teeth were x-rayed using a Schick CDR Wireless sensor at eight different exposure times - 0.06, 0.10, 0.13, 0.16, 0.20, 0.25, 0.30, and 0.32 s. Four observers evaluated the images for presence of carious lesions scoring proximal surfaces of each tooth on a 5-point scale. Scores were compared to histological sections of the teeth. Accuracy was evaluated by means of ROC curve analysis. Radiographs of an aluminum step wedge were obtained using the same eight exposure times. Pixel intensity measurements were obtained, and mean pixel values were statistically analyzed using linear regression.

Results

The Az for each exposure time varied from 0.53 to 0.62. Two-way analysis of variance and Tukey test demonstrated that the exposure time of 0.25 s presented the best result and was significantly higher than 0.30 s and 0.35 s. In regard to mean pixel values, two different behaviors were observed, and the exposure time of 0.20 s presented mean pixel values in both phases.

Conclusion

The performance of the exposure times from 0.06 s to 0.25 s was satisfactory for proximal caries detection, and 0.25 s is the best as indicated for this finality.

Clinical Relevance

Considering that a reduction of exposure time represents a reduction of patient exposure dose, and this reduction cannot neglect image quality, the behavior of any digital system must be carefully evaluated.

A comparative study on image quality of two digital intraoral sensors

OBJECTIVES

The aims of this study were to evaluate the subjective image quality and reliability of two digital sensors. In addition, the image quality of the two sensors evaluated by specialists and general dentists were compared.

METHODS

30 intraoral bitewings from five patients were included in the study, 15 were exposed with a Dixi sensor (CCD-based) and 15 with a ProSensor (CMOS-based) using modified parallel technique. Three radiologists and three general dentists evaluated the images in pair. A five-point scale was used to register the image quality. Visual grading characteristics (VGC) analysis was performed to compare the image quality and the observer agreement was assessed in terms of intra class correlation co-efficient.

RESULTS

No statistically significant difference was found on image quality between the sensors. The average scores of the observer agreement were moderate with an average of 0.66 and an interval of 0.30 to 0.87, suggesting that there was a large variation on preference of image quality. However, there was a statistically significant difference in terms of the area under the VGC- curves between the specialist group and the general dentist group ( p = 0.043), in which the specialist group tended to favor the ProSensor.

CONCLUSIONS

Subjective image quality of the two intraoral sensors were comparable when evaluated by both general and oral radiologists. However, the radiologists seemed to prefer the ProSensor to the Dixi as compared to general dentists. Inter- observer conformance showed a large variation on the preference of the image quality.

Diagnostic Accuracy of Charge-coupled Device Sensor and Photostimulable Phosphor Plate Receptor in the Detection of External Root Resorption In Vitro

Background and aims. Early diagnosis of external root resorption is important for accurate treatment. The purpose of this study was to compare the efficacy of a charge-coupled device (CCD) sensor and a photostimulable phosphor (PSP) plate receptor in the diagnosis of artificial external root resorption.

Materials and methods. In this diagnostic in-vitro study, 40 maxillary incisors were mounted in a segment of dry bone and preliminary radiographs were obtained using CCD and PSP sensors. Artificial resorption cavities were produced on the middle-third in half of the samples and on the cervical-third in the other half on the buccal root surfaces. Radiographs were repeated and images were evaluated. Data were statistically analyzed using chi-square and diagnostic tests.

Results. There were no significant differences between the two sensors in the sensitivity (p=0.08 and 0.06) and specificity (p=0.13) for the diagnosis of resorption in both root areas. The overall accuracy of CCD was higher than PSP sensor; however, the difference was not statistically significance (p>0.05).

Conclusion. CCD and PSP sensors chosen for the present study produced similar results in diagnosing simulated external root resorption.

A comparative study of different radiographic methods for detecting occlusal caries lesions

OBJECTIVES

The aim of this in vitro study was to compare the diagnostic accuracy of different radiographic imaging modalities in detecting occlusal caries lesions.

MATERIALS AND METHODS

Under standardized conditions, 125 extracted human permanent molar teeth with sound or occlusal caries lesions were radiographed using a conventional film system (F-speed), a direct digital imaging system (complementary metal oxide semiconductor sensor), an indirect digital imaging system (photostimulable phosphor plate) and a cone beam computed tomography system (CBCT). Two observers scored the resultant images for the presence or absence of caries. Then, the teeth were histologically prepared and a definite diagnosis was determined by stereomicroscopic assessment. The area under the receiver operating characteristic curve (Az), sensitivity, specificity and accuracy of each imaging modality were calculated, as well as the intra- and interexaminer reproducibility.

RESULTS

For both thresholds, interexaminer agreement were higher for CBCT. For intraexaminer agreement, observers had different scores for both thresholds, but the scores were generally higher for CBCT. Similar Az values were achieved with all imaging methods at a diagnostic D1 threshold. The Az values of the CBCT system were found to be statistically higher than those of the other imaging modalities at a diagnostic D3 threshold (p > 0.05); no significant differences were found among the other imaging modalities. All radiographic methods showed similar sensitivities, specificities and accuracy in detecting D1 threshold. The CBCT system showed higher sensitivity and accuracy in detecting dentine lesions.

CONCLUSIONS

Within the limitations of this study, CBCT exhibited better performance in detecting deep occlusal caries lesions than the other radiographic systems.

Evaluation of image quality parameters of representative intraoral digital radiographic systems

OBJECTIVE

The aim of this study was to compare imaging properties of 20 intraoral digital systems objectively.

STUDY DESIGN

Using a direct current x-ray source and a radiographic phantom, a series of radiographs was made from the lowest exposure time until the sensor saturated. Images were captured and stored. Incident exposures were measured using a radiation meter. Gray scale, spatial resolution, and contrast/detail detectability were evaluated. Presence of 7 distinct steps spanning the gray levels from 0 to 255 was used to define the exposure latitude. An "optimal" exposure, the lowest exposure where maximum spatial resolution and contrast/detail detectability were achieved, was determined.

RESULTS

The systems varied greatly in latitude, "optimal" exposure, and image quality. This may not be readily apparent to the naked eye or when clinical images are compared.

CONCLUSIONS

Objective assessment of image quality with a quality assurance tool makes it possible to evaluate and compare the various intraoral digital systems.

The Effects on Absorbed Dose Distribution in Intraoral X-ray Imaging When Using Tube Voltages of 60 and 70 kV for Bitewing Imaging

Objectives

Efforts are made in radiographic examinations to obtain the best image quality with the lowest possible absorbed dose to the patient. In dental radiography, the absorbed dose to patients is very low, but exposures are relatively frequent. It has been suggested that frequent low-dose exposures can pose a risk for development of future cancer. It has previously been reported that there was no significant difference in the diagnostic accuracy of approximal carious lesions in radiographs obtained using tube voltages of 60 and 70 kV. The aim of this study was, therefore, to evaluate the patient dose resulting from exposures at these tube voltages to obtain intraoral bitewing radiographs.

Material and Methods

The absorbed dose distributions resulting from two bitewing exposures were measured at tube voltages of 60 and 70 kV using Gafchromic^® film and an anatomical head phantom. The dose was measured in the occlusal plane, and ± 50 mm cranially and caudally to evaluate the amount of scattered radiation. The same entrance dose to the phantom was used. The absorbed dose was expressed as the ratio of the maximal doses, the mean doses and the integral doses at tube voltages of 70 and 60 kV.

Results

The patient receives approximately 40 - 50% higher (mean and integral) absorbed dose when a tube voltage of 70 kV is used.

Conclusions

The results of this study clearly indicate that 60 kV should be used for dental intraoral radiographic examinations for approximal caries detection.

The effects of image acquisition control of digital X-ray system on radiodensity quantification

Objectives

Aluminum step wedge (ASW) equivalent radiodensity (eRD) has been used to quantify restorative material's radiodensity. The aim of this study was to evaluate the effects of image acquisition control (IAC) of a digital X-ray system on the radiodensity quantification under different exposure time settings.

Materials and Methods

Three 1-mm thick restorative material samples with various opacities were prepared. Samples were radiographed alongside an ASW using one of three digital radiographic modes (linear mapping (L), nonlinear mapping (N), and nonlinear mapping and automatic exposure control activated (E)) under 3 exposure time settings (underexposure, normal-exposure, and overexposure). The ASW eRD of restorative materials, attenuation coefficients and contrasts of ASW, and the correlation coefficient of linear relationship between logarithms of gray-scale value and thicknesses of ASW were compared under 9 conditions.

Results

The ASW eRD measurements of restorative materials by three digital radiographic modes were statistically different (p = 0.049) but clinically similar. The relationship between logarithms of background corrected grey scale value and thickness of ASW was highly linear but attenuation coefficients and contrasts varied significantly among 3 radiographic modes. Varying exposure times did not affect ASW eRD significantly.

Conclusions

Even though different digital radiographic modes induced large variation on attenuation of coefficient and contrast of ASW, E mode improved diagnostic quality of the image significantly under the under-exposure condition by improving contrasts, while maintaining ASW eRDs of restorative materials similar. Under the condition of this study, underexposure time may be acceptable clinically with digital X-ray system using automatic gain control that reduces radiation exposure for patient.

Oral and dental imaging equipment and techniques for small animals

In the diagnosis and treatment of oral and dental diseases in dogs and cats, digital intraoral radiography offers many advantages over the use of standard dental radiographic film, including rapid image generation, easier exposure correction, enhancement, and paperless storage. Digital image receptors can be divided into 2 main types, direct digital systems using charged coupled devices and complementary metal oxide semiconductor sensors, and indirect digital systems using phosphor plates with a computerized scanner. Each system is paired with a computer software system to allow handling, visualization, enhancement, sharing, and archiving of the images.

Effect of ambient light level at the monitor surface on digital radiographic evaluation of approximal carious lesions: an in vitro study

OBJECTIVES

This study investigated how ambient light affects the diagnostic accuracy of dental carious lesions on monitors used in dental practice. Specifically, the aim was to evaluate whether a monitor hood for blocking excess ambient light increases practitioners' ability to accurately diagnose carious lesions on digital radiographs under bright ambient light conditions.

METHODS

7 observers evaluated approximal carious lesions on standardized digital radiographs of 100 teeth under 3 ambient light conditions: bright light (> 1000 lx) and dim light (<50 lx) with no monitor hood; and bright light with a hooded monitor. Receiver operating characteristic curves were plotted for all observations. The criterion standard was a histological examination of the teeth. A paired t-test compared the effects of the three lighting conditions. The level of significance was set to p <0.05. Weighted kappa statistics estimated intraobserver agreement.

RESULTS

The diagnostic accuracy for dentine lesions was significantly higher in ambient light<50&hairsp ;lx than on monitors with and without a hood in ambient light>1000 lx. For all observers, diagnostic accuracy of dentine lesions under bright light was higher on a hooded monitor than on a monitor without a hood, but this difference was not significant. Intraobserver agreement varied from moderate to good.

CONCLUSION

Diagnostic accuracy of those carious lesions that reached into the dentine was significantly higher in ambient light<50 lx than in ambient light>1000 lx. A hooded monitor in bright light was not as effective as a monitor without a hood in dim light.

Diagnostic accuracy of different imaging modalities in detection of proximal caries

OBJECTIVE

The purpose of this study was to assess the in vitro diagnostic ability of visual inspection, film, charge-coupled device (CCD) sensor, photostimulable phosphor (PSP) sensor and cone beam CT in the detection of proximal caries in posterior teeth compared with the histological gold standard.

METHODS

Visual inspection, film, CCD, PSP and cone beam CT images were used to detect proximal caries in the mesial and distal surfaces of 138 teeth (276 surfaces). Visual inspection and evaluation of all intraoral digital and conventional radiographs and cone beam CT images were performed twice by three oral radiologists. Weighted kappa coefficients were calculated to assess intra- and interobserver agreement for each image set, and scores were compared with the histological gold standard using receiver operating characteristic (ROC) analysis to evaluate diagnostic ability.

RESULTS

Intraobserver kappa coefficients calculated for each observer for each method of detecting caries ranged from 0.739 to 0.928. Strong interobserver agreement ranging from 0.631 to 0.811 was found for all detection methods. The highest Az values for all three observers were obtained with the cone beam CT images; however, differences between detection methods were not statistically significant (P > 0.05).

CONCLUSION

Visual inspection, film, CCD, PSP plates and cone beam CT performed similarly in the detection of proximal caries.

Gray Value Differences to Dentin of Root Posts Radiographed with Digital Intraoral Systems and Conventional X-ray Films

Digital radiographs often provide significantly higher gray value differences between root posts and root dentin than conventional x-ray films.

Modern dental imaging: a review of the current technology and clinical applications in dental practice

A review of modern imaging techniques commonly used in dental practice and their clinical applications is presented. The current dental examinations consist of intraoral imaging with digital indirect and direct receptors, while extraoral imaging is divided into traditional tomographic/panoramic imaging and the more recently introduced cone beam computed tomography. Applications, limitations and current trends of these dental "in-office" radiographic techniques are discussed.

Use of cone-beam computed tomography to identify root canal systems in vitro

This study investigated the use of cone-beam computed tomography (CBCT) as a diagnostic tool for identifying root canal systems (RCSs) when compared with images obtained by using charged coupled device (CCD) and photostimulable phosphor plate (PSP) digital radiography in vitro. Seventy-two extracted teeth were exposed with CCD, PSP, and CBCT radiography. Specimens included 24 maxillary molars, mandibular premolars, and mandibular incisors each. Tooth-type selections were based on the greater possibility of multiple RCSs. Three board-certified endodontists evaluated CCD and PSP images to determine the number of RCSs. CBCT images were used to establish "ground truth" for the comparisons and were evaluated by a board-certified oral and maxillofacial radiologist who determined the number of RCSs. Descriptive statistical analysis revealed that the endodontists consistently agreed among themselves. When compared with CBCT evaluation, the endodontists, on average, failed to identify 1 or more RCSs in 41% of the teeth with CCD and 40% of the time with PSP. CBCT evaluations identified an average of 3.58 RCSs per maxillary molar, 1.21 per mandibular premolar, and 1.5 per mandibular incisor. Evaluation of CCD images demonstrated an average number of 1.0 RCSs per mandibular incisor, 1.0 per mandibular first premolar, and 3.1 per maxillary molar. Evaluation of PSP images demonstrated an average number of 1.3 RCSs per mandibular incisor, 1.1 per mandibular first premolar, and 3.0 per maxillary molar. In summary, endodontist evaluators with either CCD or PSP methods failed to identify at least 1 RCS in approximately 4 of 10 teeth, which can result in a less optimal healing outcome if a missed RCS is left uninstrumented and unobturated.

Comparison of conventional film with different digital and digitally filtered images in the detection of simulated internal resorption cavities--an ex vivo study in human cadaver jaws

OBJECTIVE

To determine observers' ability to detect experimentally induced simulated internal resorption cavities using conventional film, digital images and digitally filtered images.

STUDY DESIGN

In the coronal plane, 11 single-rooted teeth with radiographically visible pulps were split in half. Four artificial internal resorptions were simulated in each tooth at the coronal, cervical, mid-root, and apical locations of the buccal/labial wall. Conventional and digital radiographs were taken from 3 different views in 4 steps. Three observers examined conventional, digital, and digitally filtered images for the presence of resorption cavities. Data were statistically analyzed using analysis of variance. Pair-wise comparison between receptors, location, and size were made by Tukey post hoc test.

RESULTS

One digital system produced a significantly lower proportion of correct readings, with no significant difference between other imaging types (P < .001). In the apical region, internal resorption was the most difficult to detect. The cervical region had the highest proportion of correct readings (P < .001). False-positive readings were higher in the apical and mid-root locations (P < .001). Defect size increased detection ability. Interaction was significant between receptor and size and between size and location (P < .001).

CONCLUSIONS

All systems, except PSP, produced similar results in detecting simulated internal resorption.

Diagnostic validity (or acuity) of 2D CCD versus 3D CBCT-images for assessing periodontal breakdown

OBJECTIVE

The objective of this study was to compare 2-dimensional intraoral digital images with 3-dimensional cone beam CT (CBCT) in assessment of periodontal bone levels and defects.

METHODS

Thirty periodontal bone defects of 2 adult human skulls (with soft tissue or substitute) were evaluated by using intraoral digital radiography and CBCT. Digital radiographs were made with a size #2 CCD sensor and a 60-kV DC x-ray unit, with 0.28, 0.42, or 0.56 mAs as respective exposure settings. For CBCT, jawbone images were obtained at 120 kV and 23.87 mAs. Periodontal bone levels and defects on both imaging modalities were assessed and compared to the gold standard. Delineation of lamina dura, crater defect, furcation involvements, contrast, and bone quality were also analyzed.

RESULTS

Linear measurement deviations of periodontal bone levels from the gold standard ranged from 0.19 to 1.66 mm for intraoral radiography versus 0.13 to 1.67 mm for CBCT. Accuracy was not significantly different between both imaging modalities (P = .161). Intraoral radiography scored significantly better for contrast, bone quality, and delineation of lamina dura, but CBCT was superior for assessing crater defects and furcation involvements (P = .018).

CONCLUSIONS

CBCT images allowed comparable measurements of periodontal bone levels and defects as intraoral radiography. CBCT images demonstrated more potential in the morphological description of periodontal bone defects, while the digital radiography provided more bone details. These findings may offer perspectives for further studies on periodontal diagnostics, prognostics, and presurgical planning with CBCT.

Digital and Advanced Imaging in Endodontics: A Review

This review provides an overview of digital radiography as it exists, including advanced imaging such as computed tomography (CT), cone beam volumetric imaging, and micro-CT as relevant to the practice of endodontics. An evidence-based approach to adoption of different imaging technologies is included to assist the practitioner with the selection process of imaging modalities. Commonly used imaging terminology is introduced, as well as the advantages and disadvantages of image processing. New image reconstruction techniques have been introduced that provide information three-dimensionally to the clinician for routine endodontic and surgical treatment planning. The age of three-dimensional imaging and image processing is here. Limitations and advantages of newly introduced imaging modalities are discussed briefly.

Filmless imaging

BACKGROUND

As use of digital radiography becomes more common, many dentists are wondering if and how they can replace conventional film-based imaging with a digital system. This article briefly describes the different technologies used for digital radiography in dentistry. The article provides general practitioners with a broad overview of the benefits and limitations of digital radiography to help them understand the role the technology can play in their practices.

OVERVIEW

The two technologies now available are solid-state systems and phosphor plate systems. Each has its strong points, and the choice of which to use depends on the type of dental practice. Image processing improves the diagnostic quality of the radiographic information. Advanced image-processing techniques, such as subtraction radiography, are available for specialized clinics.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Digital radiography no longer is an experimental modality. It is a reliable and versatile technology that expands the diagnostic and image-sharing possibilities of radiography in dentistry. Optimization of brightness and contrast, task-specific image processing and sensor-independent archiving are important advantages that digital radiography has over conventional film-based imaging.