Bitewing Radiographs Research Articles

The value of bitewing radiographs in the management of carious primary molars - the impact on treatment planning.

Introduction Bitewing radiographs (BWs) with visual examination (VE) are critical for the early detection of caries in primary molars. However, their influence on treatment planning is not extensively studied. Given they involve exposure to ionising radiation, it is essential to understand their impact on treatment decisions.Aim To explore the impact of BWs in the management of carious primary molars.Design Cross-sectional study.Materials and methods A total of 30 children (mean age 6.2 years) referred for caries management in a dental hospital setting were recruited. One of six paediatric dental specialists performed VEs and scored pre-BW treatment needs (TN) for each primary molar, followed by reviewing the BWs, re-scoring TN and recording their opinion on treatment modality. Data were assessed using descriptive analyses. Five treatment planning descriptors detailing the reasons for change were identified.Results In total, 240 primary molars were examined. BWs resulted in an overall change in treatment plan for 24/30 (80.0%) children, with the majority (20/30; 66.7%) becoming more invasive. General anaesthesia was the commonest proposed modality (13/30; 43.3%) children), followed by inhalation sedation (10/30; 33.3%) and local anaesthesia (6/30; 20.0%), with only one child (3.3%) in the 'no analgesia' modality.Conclusion BWs play an important role in treatment planning carious primary molars.

Automatic caries detection in bitewing radiographs: part I-deep learning.

The aim of this work was to assemble alarge annotated dataset of bitewing radiographs and to use convolutional neural networks to automate the detection of dental caries in bitewing radiographs with human-level performance. A dataset of 3989 bitewing radiographs was created, and 7257 carious lesions were annotated using minimal bounding boxes. The dataset was then divided into 3 parts for the training (70%), validation (15%), and testing (15%) of multiple object detection convolutional neural networks (CNN). The tested CNN architectures included YOLOv5, Faster R-CNN, RetinaNet, and EfficientDet. To further improve the detection performance, model ensembling was used, and nested predictions were removed during post-processing. The models were compared in terms of the [Formula: see text] score and average precision (AP) with various thresholds of the intersection over union (IoU). The twelve tested architectures had [Formula: see text] scores of 0.72-0.76. Their performance was improved by ensembling which increased the [Formula: see text] score to 0.79-0.80. The best-performing ensemble detected caries with the precision of 0.83, recall of 0.77, [Formula: see text], and AP of 0.86 at IoU=0.5. Small carious lesions were predicted with slightly lower accuracy (AP 0.82) than medium or large lesions (AP 0.88). The trained ensemble of object detection CNNs detected caries with satisfactory accuracy and performed at least as well as experienced dentists (see companion paper, Part II). The performance on small lesions was likely limited by inconsistencies in the training dataset. Caries can be automatically detected using convolutional neural networks. However, detecting incipient carious lesions remains challenging.

Proximal Caries Detection Using Short-Wave Infrared Transillumination at Wavelengths of 1050, 1200 and 1300 nm in Permanent Posterior Human Teeth.

This in vitro study aimed to investigate the diagnostic potential of short-wave infrared transillumination (SWIRT) at 1050, 1200 and 1300 nm for the detection of proximal caries in molars and premolars. It was compared to the diagnostic performance of bitewing radiography (BWR) and micro-computed tomography (µCT) as the reference standard. 250 sound or decayed proximal surfaces of permanent posterior extracted teeth were examined using (1) SWIRT at 1050, 1200 and 1300 nm with two camera systems of different resolutions, (2) BWR and (3) µCT. Thresholds were defined for both test methods and the reference standard for caries in general, enamel caries and dentin caries. All images were assessed by two examiners twice, at an interval of two weeks. SWIRT at wavelengths of 1050, 1200 and 1300 nm achieved sensitivity values more than 2.5 times higher than BWR (enamel caries 3.2-4.4 times; dentin caries 3.25-4.25 times) for the detection of proximal caries. Sensitivity values of SWIRT improved with the higher wavelength. No significant difference was found in diagnostic quality between the two camera systems. SWIRT at 1300 nm imaged proximal enamel caries with the highest accuracy, while the physical optimum for transillumination in dentin was located at a lower wavelength (<1000 nm).

The Use of Extra-oral Bitewing Radiographs for Treatment Planning in Paediatric Patients

The extra-oral bitewing is becoming increasingly popular among clinicians to help overcome some of the challenges posed when taking intra-oral radiographs for paediatric patients. When combined with clinical examination, this radiographic view provides important diagnostic information in the management of caries in the posterior dentition. In this article, the use of extra-oral bitewings will be explored. The introduction of a decision tree provides the dental practitioner working in either a primary or secondary care setting, a pathway to assist with deciding the optimal radiographic prescription. CPD/Clinical Relevance: Extra-oral bitewings can be a useful radiographic tool for dental caries diagnosis in the mixed dentition.

Prediction of pulp exposure before caries excavation using artificial intelligence: Deep learning-based image data versus standard dental radiographs

ObjectivesThe objective was to examine the effect of giving Artificial Intelligence (AI)-based radiographic information versus standard radiographic and clinical information to dental students on their pulp exposure prediction ability. Methods292 preoperative bitewing radiographs from patients previously treated were used. A multi-path neural network was implemented. The first path was a convolutional neural network (CNN) based on ResNet-50 architecture. The second path was a neural network trained on the distance between the pulp and lesion extracted from X-ray segmentations. Both paths merged and were followed by fully connected layers that predicted the probability of pulp exposure. A trial concerning the prediction of pulp exposure based on radiographic input and information on age and pain was conducted, involving 25 dental students. The data displayed was divided into 4 groups (G): GX-ray, GX-ray+clinical data, GX-ray+AI, GX-ray+clinical data+AI. ResultsThe results showed that AI surpassed the performance of students in all groups with an F1-score of 0.71 (P < 0.001). The students’ F1-score in GX-ray+AI and GX-ray+clinical data+AI with model prediction (0.61 and 0.61 respectively) was slightly higher than the F1-score in GX-ray and GX-ray+clinical data (0.58 and 0.59 respectively) with a borderline statistical significance of P = 0.054. ConclusionsAlthough the AI model had much better performance than all groups, the participants when given AI prediction, benefited only ‘slightly’. AI technology seems promising, but more explainable AI predictions along with a 'learning curve' are warranted.

Use of Digital Diagnostic Aids for Initial Caries Detection: A Review.

The advance in digital diagnostic technologies has significantly facilitated the detection of dental caries. Despite the increase in clinically available digital diagnostic aids for dental caries, there is yet to be a comprehensive summary of all available technology. This review aims to provide an overview of digital diagnostic aids for the clinical detection of dental caries, particularly those at an initial stage. Currently available digital diagnostic aids for caries detection can be classified into four categories according to the initial source of energy, including radiation-based aids, light-based aids, ultrasound-based aids, and electric-based aids. Radiation-based aids use ionizing radiation, normally X-ray, to produce images of dental structures. Radiation-based aids encompass digital bitewing radiography and cone beam computed tomography. Light-based aids employ light or laser to induce signals for the detection of the changes in the carious dental hard tissue. Common light-based aids include digital transillumination and light/laser-induced fluorescence. Ultrasound-based aids detect the signal of ultrasound waves to assess the acoustic impedance of the carious teeth. The ultrasound caries detector is an available ultrasound-based aid. Electric-based aids assess the changes in the electric current conductance or impedance of the teeth with caries. Available electric-based aids include electrical conductance measurement and alternating current impedance spectroscopy. Except for these clinically available digital diagnostic aids, many digital diagnostic aids for caries detection are still under development with promising results in laboratory settings.

Performance of the caries diagnosis feature of intraoral scanners and near-infrared imaging technology-A narrative review.

To describe and discuss the benefits and drawbacks of various dental caries diagnostic techniques, including the use of intraoral scanners for caries diagnosis based on near-infrared imaging (NIR) technology. A MEDLINE search from 1980-2023 focused on dental caries diagnostic techniques, emphasizing intraoral scanners using NIR technology. Alternative caries detection methods were also evaluated for their advantages and limitations, enabling a comparison with NIR. The review included traditional caries tools, the latest detection methods, and NIR's role in intraoral scanners, drawing from case reports and both in vivo and in vitro studies. Keywords like "caries detection," "intraoral scanners," and "Near Infrared Imaging (NIRI)" guided the search. After screening titles and abstracts for relevance, full texts with valuable insights were thoroughly analyzed. The data was grouped into three: traditional diagnostics, advanced digital methods, and intraoral scanner-based detection. This comprehensive narrative review described and discussed the current state of dental caries diagnostic methods, given the insufficient number of clinical investigations suitable for a systematic review. Traditional caries diagnosis techniques have shown variable accuracy dependent on a dentist's experience and the potential over-removal of healthy tooth structures. Intraoral scanners have emerged as a novel caries detection method, because of their integration of NIR technology. Various studies have confirmed the efficacy of NIR in detecting interproximal caries and in the early diagnosis of non-cavitated caries. Specifically, intraoral scanners have demonstrated promising results, proving comparable to established diagnostic methods like bitewing radiography. Nevertheless, while the integration of NIR into intraoral scanners seems promising, the technology still faces challenges, notably its accuracy in detecting secondary and subgingival cavities. However, with anticipated integrations of AI, NIR in intraoral scanners could revolutionize early caries detection. Intraoral scanners with NIR technology offer non-destructive imaging, real-time lesion visuals, and enhanced patient communication. Although comparable to bitewing radiography in some studies, a universally accepted diagnostic tool is lacking. Future research should compare them with existing methods, focusing on clinical outcomes, cost-effectiveness, and patient acceptance.

Assessment of the Correlation Between Systemic Conditions and Pulp Canal Calcification: A Case-Control Study.

Pulp canal calcification is a dental condition that is characterized by the deposition of mineralized tissue within the dental pulp space. While it is primarily a local phenomenon, recent studies have suggested a potential link between pulp calcification and systemic diseases. This study aimed to determine the correlation between certain systemic diseases, medications, and the presence of pulp canal calcification. Second, it aimed to estimate the prevalence of pulp calcification in the smoker population. A pair-matched case-control observational study was conducted from June 2022 to June 2023 at the Faculty of Dentistry, King Abdulaziz University. Digital periapical and bitewing radiographs were used for case-based sampling. Patients were categorized into two study groups: the cases group (n=100), consisting of patients with pulp canal calcification including either pulp stone, pulp canal obliteration, or both. Whereasthe control group (n=100), consisted of patients without pulp canal calcification.Detailed medical histories were obtained to identify the presence of systemic diseases. Additionally, systemic medications and smoking status were documented. The participants were divided into two groups; cases (n=100), diagnosed with teeth calcifications and confirmed by radiographic examination, and controls (n=100), showing no evidence of teeth calcifications. Among the patients in the calcification group, 26% had a history of systemic disease compared to 17% in the control non-calcification group with no significant difference between both groups. No correlation between certain medications and pulp canal calcification. Smoking did not demonstrate a statistically significant association with teeth calcifications (p > 0.05). Pulp calcification on routine radiographic examination could indicate an underlying unnoticed systemic disorderthat demands accurate referral and subsequent therapy.

Caries detection and characterization in pediatric patients using iTero 5D near-infrared technology

Near-infrared imaging (NIRI) has been proposed as an alternative to radiographs and uses nonionizing radiation in the near-infrared spectrum to differentially scatter light off tooth surfaces and generate images allowing interproximal caries detection. The new iTero 5D Element Scanner (Align Technology, Santa Clara, Calif) has integrated NIRI capture and viewing technology but has not been specifically studied in a pediatric population. Therefore, this study aimed to assess clinicians' abilities to detect and characterize caries in pediatric patients using this instrument. Bitewing (BW) radiographs and an intraoral scan were captured on 17 pediatric patients (344 surfaces were analyzed). Data were randomized and graded by 5 calibrated clinicians individually with 2 different rounds of grading. The reliability of lesion characterization (ie, grade) among examiners was poor to fair in both systems, whereas the reliability of caries detection was moderate. Both systems had a high specificity and low sensitivity. The reliability of the characterization of the combined dataset was moderate to substantial, whereas, for detection, it was substantial. When using either BW or NIRI analysis, reliability is relatively poor, and clinicians are more likely to correctly identify a healthy tooth surface when compared with a carious surface. There is a small difference in error rate between BW and NIRI systems that is not likely to be clinically significant. When NIRI and BW data are combined, clinician agreement for both lesion characterization and detection increases significantly.

Radiation doses in extraoral bitewing radiography compared with intraoral bitewing and panoramic radiography

We compared the effective dose (E) and thyroid equivalent dose of 2 extraoral bitewing (EOBW) units and compared E with their respective panoramic (PAN) modes and with intraoral bitewing radiography (IOBW). Child and adult anthropomorphic phantoms with dosimeters were used to evaluate Orthophos SL, Rayscan α+, and 1 intraoral unit using rectangular and circular collimation. Extraoral bitewing thyroid equivalent dose was assessed without and with thyroid shielding. Child and adult E values of EOBW were lower with Orthophos (3.6 and 8.6 μSv) than with Rayscan (28.1 and 30.2 μSv). For IOBW, E was lower with rectangular vs circular collimation for child (7.0 vs 11.8 μSv) and adult (4.6 vs 14.2 μSv). E values of EOBW were lower than PAN for Orthophos. The IOBW E was lower than Rayscan EOBW for child (≤11.8 vs 28.1 μSv) and adult (≤14.2 vs 30.2 μSv). Adult E for rectangular IOBW (4.6 μSv) was lower than EOBW with Orthophos (8.6 μSv) and Rayscan (30.2 μSv). Thyroid shielding reduced EOBW thyroid equivalent dose with Rayscan in the adult from 190.7 to 89.0 μSv. Orthophos provides significantly lower EOBW E than Rayscan, thus EOBW recommendations must be unit specific. For children, Orthophos EOBW could be an alternative to IOBW, for which rectangular collimation is recommended. Thyroid shielding reduced adult Rayscan equivalent dose but added imaging artifacts.

Real-Time Caries Detection of Bitewing Radiographs Using a Mobile Phone and an Artificial Neural Network: A Pilot Study

This pilot study aimed to implement and assess the performance of an experimental artificial intelligence (AI) mobile phone app in the real-time detection of caries lesions on bitewing radiographs (BWRs) with the use of a back-facing mobile phone video camera. The author trained an EfficientDet-Lite1 artificial neural network using 190 radiographic images from the Internet. The trained model was deployed on a Google Pixel 6 mobile phone and used to detect caries on ten additional Internet BWRs. The sensitivity/precision/F1 scores ranged from 0.675/0.692/0.684 to 0.575/0.719/0.639 for the aggregate handheld detection of caries in static BWRs versus the stationary scanning of caries in a moving video of BWRs, respectively. Averaging the aggregate results, the AI app detected—in real time—62.5% of caries lesions on ten BWRs with a precision of 70.6% using the back-facing mobile phone video camera. When combined with the AI app’s relative ease of use and speed and the potential for global accessibility, this proof-of-concept study could quite literally place AI’s vast potential for improving patient care in dentists’ hands.

Enhancing Caries Detection in Bitewing Radiographs Using YOLOv7.

The study aimed to evaluate the impact of image size, area of detection (IoU) thresholds and confidence thresholds on the performance of the YOLO models in the detection of dental caries in bitewing radiographs. A total of 2575 bitewing radiographs were annotated with seven classes according to the ICCMS™ radiographic scoring system. YOLOv3 and YOLOv7 modelswere employed with different configurations, and their performances were evaluated based on precision, recall, F1-score and mean average precision (mAP). Results showed that YOLOv7 with 640 × 640pixel images exhibitedsignificantly superior performance compared to YOLOv3 in terms of precision (0.557 vs. 0.268), F1-score (0.555 vs. 0.375) and mAP (0.562 vs. 0.458), while the recall was significantly lower (0.552 vs. 0.697). The following experiment found that the overall mAPs did not significantly differ between 640 × 640 pixel and 1280 × 1280 pixelimages, for YOLOv7 with an IoU of 50% and a confidence threshold of 0.001 (p = 0.866). The last experiment revealed that the precision significantly increased from 0.570 to 0.593 for YOLOv7 with an IoU of 75% and a confidence threshold of 0.5, but the mean-recall significantly decreased and led to lower mAPs in both IoUs. In conclusion, YOLOv7 outperformed YOLOv3 in caries detection and increasing the image size did not enhance the model's performance. Elevating the IoU from 50% to 75% and confidence threshold from 0.001 to 0.5 led to a reduction of the model's performance, while simultaneously improving precision and reducing recall (minimizing false positives and negatives) for carious lesiondetection in bitewing radiographs.

Clinical evaluation of zirconia crowns cemented with two different resin cements: A retrospective study.

Self-adhesive resin cement has been used extensively with zirconia crowns. Several in vitro studies showed that adhesive resin cementation may increase zirconia crowns' retention and their fatigue resistance. This retrospective study aimed to evaluate the clinical performance, survival and success rates and complications encountered with zirconia crowns cemented with two different self-adhesive resin cements. A total of 112 patients who received 176 monolithic zirconia crowns were evaluated. Crowns were cemented with RelyX Unicem 2 (n = 74) and Panavia SA (n = 102) self-adhesive resin cements. Clinical assessments of the crowns and supporting periodontal structures were performed following the modified California Dental Association (CDA) criteria. Intraoral photographs and periapical and bitewing radiographs were obtained for further assessment by two evaluators. Descriptive statistics, McNemar, t-test, log rank (Mantel-Cox) tests and Kaplan-Meier survival analyses were performed (a = .05). The 5-year survival and success rates were 100% and 96.4%, respectively. The complications encountered were recurrent caries (2.2%) and the need for endodontic treatment (0.5%). No technical complications, such as fracture or loss of retention, were observed. The type of cement and patient-related factors did not influence the survival and success rates of the crowns. Survival rate of zirconia crowns cemented with two different self-adhesive resin cements was 100% after 5 years.

Remineralizing potential of the biomimetic P11-4 self-assembling peptide on noncavitated caries lesions: A retrospective cohort study evaluating semistandardized before-and-after radiographs

BackgroundSelf-assembling peptide (SAP) P11-4 was introduced to treat initial caries lesions by means of guiding hydroxyapatite regeneration within the lesion. The objective of this study was to assess its effectiveness in a practical clinical setting. MethodsCaries lesions in permanent teeth treated with monomeric and polymeric SAP P11-4 from May 2015 through October 2020 were retrospectively analyzed at lesion and child levels by means of bite-wing radiography for changes in stage and cavitation and restoration. ResultsTwo hundred and nineteen children aged 10 through 19 years with a total of 405 proximal lesions in posterior teeth were followed from 0.4 through 5.5 years (median, 7 months; interquartile range, 6-19 months). Regression occurred in 37% of stage RA1 (radiolucency in the outer one-half of enamel) (95% CI, 31% to 44%), 38% of stage RA2 (radiolucency in the inner one-half of enamel plus or minus the enamel–dentin junction) (95% CI, 30% to 45%), and 40% of stage RA3 (radiolucency limited to the outer one-third of dentin) (95% CI, 16% to 68%) lesions. The proportion of lesions with no cavitation was 0.96 (95% CI, 0.94 to 0.98) after 1 year and 0.91 (95% CI, 0.88 to 0.95) after 2 years. ConclusionsReal-world clinical data indicate that SAP P11-4 can lead to recovery and a healthier tooth stage. Practical ImplicationsSAP P11-4 is a safe treatment for initial caries lesions in permanent teeth that remineralizes in the deepest zone of the lesion and can be introduced easily into routine dental practice.

Clinical validation of near-infrared imaging for early detection of proximal caries in primary molars

ObjectivesThe aim of this study was to validate the near-infrared imaging (NIRI) in comparison with visual inspection (VI) for early detection of proximal caries in primary molars. MethodsVI and intraoral scans were performed on 126 patients aged 3–12 years with at least one non-cavitied and non-restored proximal tooth surface, who were scheduled for bite wing radiography (BWR) as part of their standard care. Teeth with signs of proximal cavities, restorations or residual caries were excluded in this study. BWR, a gold standard to diagnose proximal caries in primary molars, was used to validate the findings of NIRI and VI. The accuracy, sensitivity, specificity and the area under the curve (AUC) of NIRI and VI were calculated. ResultsThe accuracy, sensitivity and specificity of NIRI were 82.89%, 74.10% and 90.97%, while those of VI were 71.64%, 43.88% and 97.14%, respectively. NIRI showed higher accuracy and sensitivity, and lower specificity (P < 0.001). The AUC of NIRI was higher than that of VI (0.826 vs 0.706; P < 0.05). ConclusionsNIRI showed higher sensitivity and lower specificity compared with VI when detecting proximal caries in primary molars. Therefore, it is recommended to use NIRI in combination with BWR to improve the detection rate of proximal caries in primary molars. Clinical significanceIn children, there is a high incidence of proximal caries in primary molars, which require high technical sensitivity for detection. NIRI shows high sensitivity in detecting proximal caries, which may improve their detection rate in primary molars.The clinical trial registration number: ChiCTR2300070916

Underlying Dentin Shadows (ICDAS 4) in Occlusal Surface of Permanent Teeth Have Low Progression Rate after 1–2 Years

The aim of this prospective cohort study was to assess the radiographic progression of underlying dentin shadows (UDS) on the occlusal surfaces of permanent posterior teeth of adolescents and young adults over 1–2 years and to identify possible risk factors. A total of 149 UDS lesions (from 101 individuals) were included at baseline. Each participant had to present at least one UDS to be considered eligible for the study. Data collection included the application of a questionnaire, clinical examination, and bilateral bitewing radiographs, performed at baseline and after 1–2 years. The association between possible predictors and UDS progression (defined radiographically as an increase in the radiographic score from baseline to follow-up) was assessed using Weibull regression models. Hazard ratios (HRs) and their 95% confidence intervals (CIs) were estimated. A total of 81 individuals (mean age: 24.0, standard deviation: 8.03) were reexamined after 1–2 years (742 occlusal surfaces, of which 118 were UDS). The overall progression rate was 8.6% after 1–2 years, being 12.6% for UDS without baseline radiolucency and 20% for UDS with baseline radiolucency. The risk analysis showed that UDS without radiolucency at baseline had a similar likelihood of progression (adjusted HR = 1.71, 95% CI = 0.68–4.32, p = 0.26) while UDS with radiolucency at baseline were more likely to progress (adjusted HR = 2.96, 95% CI = 1.06–8.26, p = 0.04) than the reference category (sound occlusal surfaces without radiolucency). These estimates were adjusted for caries prevalence, tooth type, and arch. This study showed low progression rates of UDS after 1–2 years. The presence of radiolucency at baseline was found to predict UDS progression.

Selective Removal to Soft Dentine versus Full Pulpotomy for Management of Proximal Deep Carious Lesions: A Randomized Controlled Non-Inferiority Trial

The management of the deep carious lesion with reversible pulpitis is a dilemma for the dentist. The current study compared selective removal to soft dentine (SRSD) and full pulpotomy (FP) for treating proximal deep carious lesions in teeth with reversible pulpitis. Visual-tactile examination and bitewing radiographs were used to determine the depth of carious lesion, and American Association of Endodontists recommendations were used to formulate pulp diagnosis. Sixty mandibular molar teeth from healthy patients between the ages of 16–35 years and a diagnosis of proximal deep carious lesion with reversible pulpitis were included. Teeth were randomly allocated to two study groups. SRSD group (n = 30): soft dentine was preserved over the pulpal aspect. A hard-setting calcium hydroxide cement liner and resin-modified glass ionomer cement base were applied over the remaining soft carious dentine. FP group (n = 30): complete caries removal followed by mineral trioxide aggregate FP was performed. The teeth in both groups were restored with composite resin restoration. The established criteria for outcome assessment of SRSD and pulpotomy were used. Accordingly, only asymptomatic teeth with no radiological evidence of periapical rarefaction were considered successful at the 12-month follow-up. Two-sample t test, Pearson χ² test/Fisher’s exact test, and percentage agreement were used for statistical evaluation. According to the per-protocol analysis, the success rate of both SRSD and FP treatment was 95.45% and 95.65%, respectively, and the actual difference between the two treatments was 1% (95% CI: [−10, 9]). The data suggests that both treatments (SRSD and FP) appear to have a good success rate (>95%) when used to manage permanent mandibular molar teeth with proximal deep carious lesion and reversible pulpitis. As SRSD is a noninvasive procedure, it should be favored over FP in these instances.

Computed vs. film-based radiographs' contour artifacts influence diagnosis of secondary caries

To test local grey-scale changes on dental bitewing radiographs near filling margins for image acquisition. Forty approximal preparations in caries-free amalgam filled teeth and bitewing radiographs were acquired under standardized conditions applying four techniques. Film-based analog radiographs were digitized using flat-bed scanner (FDR). Phosphor-plate computed radiographs (PCR) were directly acquired by scanning VistaScan imaging plates. Image quality was tested using Preset Filter (PF) or manually applied IntraOral Fine Filter (IF) to enhance digital images. Local changes from digital imaging processing were assessed by comparing the margin-near (MN) and margin-far (MF) zone by a multivariate repeated measurements analysis. All images were acquired with 8-bit depth (256 shades). Dentine was displayed in 79 shades for FDR and 54 shades for PCR. PF or IF locally modify bitewing radiographs by darkening marginal dentine by 8 or 29 shades, respectively. The sharpest display of the margin (shades per pixel) from dentine to filling was found for IF (26.2), followed by FDR (23.2), PF (15.3) and PCR (8.3). Computed radiography with phosphor plates generate more homogeneous images compared to flatbed-digitized film-based radiographs. The filling margin was sharpest represented with the IF filter at the detriment of an artificial darkening of the dentine near the margin of the filling. Contour artifacts by filters have the potential to confound diagnosis of secondary caries. Algorithms and filters for sensor data processing, causing local changes above 2% of the dynamic range by non-continuous mathematical functions, should only be applied with caution, manually when diagnosing and reversibly.

Artificial Intelligence Techniques for Automatic Detection of Peri-implant Marginal Bone Remodeling in Intraoral Radiographs

Peri-implantitis can cause marginal bone remodeling around implants. The aim is to develop an automatic image processing approach based on two artificial intelligence (AI) techniques in intraoral (periapical and bitewing) radiographs to assist dentists in determining bone loss. The first is a deep learning (DL) object-detector (YOLOv3) to roughly identify (no exact localization is required) two objects: prosthesis (crown) and implant (screw). The second is an image understanding-based (IU) process to fine-tune lines on screw edges and to identify significant points (intensity bone changes, intersections between screw and crown). Distances between these points are used to compute bone loss. A total of 2920 radiographs were used for training (50%) and testing (50%) the DL process. The mAP@0.5 metric is used for performance evaluation of DL considering periapical/bitewing and screws/crowns in upper and lower jaws, with scores ranging from 0.537 to 0.898 (sufficient because DL only needs an approximation). The IU performance is assessed with 50% of the testing radiographs through the t test statistical method, obtaining p values of 0.0106 (line fitting) and 0.0213 (significant point detection). The IU performance is satisfactory, as these values are in accordance with the statistical average/standard deviation in pixels for line fitting (2.75/1.01) and for significant point detection (2.63/1.28) according to the expert criteria of dentists, who establish the ground-truth lines and significant points. In conclusion, AI methods have good prospects for automatic bone loss detection in intraoral radiographs to assist dental specialists in diagnosing peri-implantitis.

Prevalence of peri-implantitis after alveolar ridge preservation at periodontitis and nonperiodontitis extraction sites: A retrospective cohort study.

Periodontitis is the main indication for dental extraction and often leads to peri-implantitis (PI). Alveolar ridge preservation (ARP) is an effective means of preserving ridge dimensions after extraction. However, whether PI prevalence is lower after ARP for extraction after periodontitis remains unclear. This study investigated PI after ARP in patients with periodontitis. This study explored the 138 dental implants of 113 patients. The reasons for extraction were categorized as periodontitis or nonperiodontitis. All implants were placed at sites treated using ARP. PI was diagnosed on the basis of radiographic bone loss of ≥3 mm, as determined through comparison of standardized bitewing radiographs obtained immediately after insertion with those obtained after at least 6 months. Chi-square and two-sample t testing and generalized estimating equations (GEE) logistic regression model were employed to identify risk factors for PI. Statistical significance was indicated by p < 0.05. The overall PI prevalence was 24.6% (n = 34). The GEE univariate logistic regression demonstrated that implant sites and implant types were significantly associated with PI (premolar vs. molar: crude odds ratios [OR] = 5.27, 95% confidence intervals [CI] = 2.15-12.87, p = 0.0003; bone level vs. tissue level: crude OR = 5.08, 95% CI = 2.10-12.24; p = 0.003, respectively). After adjustment for confounding factors, the risks of PI were significantly associated with implant sites (premolar vs. molar: adjusted OR [AOR] = 4.62, 95% CI = 1.74-12.24; p = 0.002) and implant types (bone level vs. tissue level: AOR = 6.46, 95% CI = 1.67-25.02; p = 0.007). The reason for dental extraction-that is, periodontitis or nonperiodontitis-was not significantly associated with PI. ARP reduces the incidence of periodontitis-related PI at extraction sites. To address the limitations of our study, consistent and prospective randomized controlled trials are warranted.