2-year survival and cost analysis of occlusoproximal ART restorations using encapsulated glass ionomer cement in primary molars: a randomized controlled trial.

BACKGROUND: The survival of ART restorations can be influenced by the choice of the restorative material. The aim of this randomized non-inferiority controlled trial was to compare the 2-year survival rate and cost analysis of two encapsulated glass ionomer cements (GIC) as occlusoproximal restorative materials in primary molars. METHODS: Children from public schools in Tietê (Brazil), aged 4-8 years with occlusoproximal dentine carious lesions in primary molars were selected and randomly assigned to receive either Equia Forte (EF) or Riva Self Cure (RSC) as restorative materials. Treatment was carried out by two trained final-year dental students in schools following ART premises. Restorations were assessed by a trained and calibrated examiner after 2, 6, 12, 18, and 24 months. The primary outcome was restoration survival after 2 years, analyzed using Kaplan-Meier survival and Cox regression analysis (α = 5%). Professional and materials costs for each group were collected in Brazilian Reais (R$) and converted into US dollars (US$) and analyzed using Monte-Carlo simulation. RESULTS: A total of 152 children (76 per group) were included in the study, and 121 (79%) were evaluated after 2 years. The overall 2-year restoration survival rate was 39% (EF = 45%; RSC = 32%) with no difference between the groups. The baseline and 2-year total cost of restorations using RSC was lower when compared to EF (incremental cost: US$ 6.18). CONCLUSION: After two years of follow-up, Riva Self Cure shows comparable restoration survival rates to Equia Forte, being more cost-effective in the Brazilian perspective. TRIAL REGISTRATION: This randomized clinical trial was registered on ClinicalTrials.Gov - NCT02730000.

The effect of cone beam computerized tomography voxel size and the presence of root filling on the assessment of middle mesial canals in mandibular molar teeth.

INTRODUCTION: The study aims to compare the detection of the middle mesial canal (MMC) in mandibular molar teeth using cone beam computed tomography (CBCT) with different voxel sizes when the mesiobuccal (MB) and mesiolingual (ML) canals have three distinct phases (unpreparation, preparation and obturation and the removal of the obturation and repreparation). METHODS: Two hundred forty-two extracted human mandibular molars were collected and kept in a physiological saline solution prior to use. 0.2-, 0.28- and 0.35-mm voxel sizes CBCT (n = 242) were performed in three phases (Ph): Ph1, no MB and ML canal preparation or obturation; Ph2, after MB and ML canals preparation and obturation; and Ph3, after the removal of the obturation of MB and ML canals and canals repreparation. Images were analyzed using OnDemand3D® software. After the CBCT acquisition in Ph3, all the samples were clarified to visualize the presence of the MMC directly. A blinded, previously calibrated examiner analyzed all the images. RESULTS: The MMC was detected in 15 of the 242 teeth after the clearing technique. The lowest MMC detection rate was observed at 0.35-mm voxel size regardless of the ML and MB canal condition, while the highest was observed at 0.2-mm voxel size (P < 0.05). There is no statistically significant difference between 0.2-mm and 0.28-mm voxel sizes (P > 0.05). In all voxel sizes, the highest rate of detectability of the MMC was seen in Phase 1, while the lowest was in Phase 2. CONCLUSIONS: It may be appropriate to take a 0.20-mm voxel size CBCT image, especially after the removal of root canal filling. CLINICAL RELEVANCE: An appropriate CBCT voxel size and the absence of root canal filling in the root canal system help to detect the missing MMC.

Assessment of the Shaping Ability of R-Motion 30 .04 and 25 .06 in Mesial Canals of Mandibular Molars Based on Automated Computational Measurement.

INTRODUCTION: The aim of this study was to evaluate changes in geometry following root canal preparation using R-Motion instruments with different apical sizes and tapers. METHODS: Fifty-four mesial canals of mandibular molars with single curvature of angles ranging between 20° and 30° were stratified into 3 groups according to their internal anatomy (R-Motion 25/.06, 30/.04, Reciproc Blue) (n = 18 per group). Micro-computed tomography was used to standardize the samples before instrumentation and, after instrumentation, to assess canal transportation, changes in canal volume and centering ability. Canals were irrigated with 17% EDTA and sodium hypochlorite, and the final rinse included subsonic agitation of these solutions. Measurements were analyzed automatically using the Dragonfly software (Come, Montreal, Canada) and were confirmed by a technician and an endodontist, based on a previously validated methodology. The results were analyzed using the Kruskal-Wallis's and Mann-Whitney's tests. The level of statistical significance was set at 5%. RESULTS: Significant differences were found in the coronal third for canal transportation, with Reciproc Blue R25 having greater values compared with both R-Motion instruments (P < .05) and greater changes in volume when compared with R-Motion 30/.04 (P < .05). CONCLUSIONS: R-Motion of apical size and taper 25/.06 and 30/.04 were associated with similar changes in geometry following root canal preparation in curved mesial canals of mandibular molars, whereas Reciproc Blue was associated with greater canal transportation in the coronal root third.

The Assessment of Resin-Based Composite Sealants' Effectiveness in Arresting Non-Cavitated Dentin Carious Lesions (ICDAS 3)-A 12 Month Follow-Up Preliminary Study.

Background and Objectives: The therapeutic management of carious lesions remains a significant focus for researchers, given their persistently high prevalence despite being largely preventable. This study aimed to compare the effectiveness of a composite resin-based sealant material in halting extended non-cavitated dentin carious lesions when used therapeutically versus preventively on caries-free teeth over a period of twelve months. Materials and Methods: out of the 236 children examined, 45 were excluded from the study due to non-compliance with the inclusion criteria. Thus, the study included 191 children aged 10-12 years, and 764 molars in total. Results: among these molars, 171 were caries-free (ICDAS II code 0), forming the Control group, while 180 molars were classified with an ICDAS II score of 3, forming the Study group. All molars were sealed and evaluated at 6- and 12-month follow-up intervals. Both intervals revealed statistically significant differences (p < 0.05) in sealant retention and carious lesion development between sound (ICDAS code 0) and decayed (ICDAS code 3) teeth. Conclusions: the findings did not support the effectiveness of sealants in halting non-cavitated dentin carious lesions classified as ICDAS II with code 3 compared to their preventive application in sound teeth classified as ICDAS II with code 0.

Assessment of the efficiency of dental excavation methods using laser speckle imaging.

This paper introduces a novel application of the laser speckle technique in dentistry, focusing on assessing the efficiency of dental excavation methods used to remove decayed tooth structure. The aim is to evaluate the efficiency of two chemo-mechanical agents and the high-speed drill using the laser speckle technique, which offers objective, non-invasive, and real-time evaluation capabilities. Extracted human primary molars with active occlusal carious lesions were sectioned into three parts, with each part allocated to one of three groups: Group 1 (Brix3000®), Group 2 (Papacarie DUO®), and Group 3 (High-speed drill mechanical caries removal). Caries removal was performed using the designated agent or method for each group. After caries excavation, speckle imaging using a 632.8 nm laser was conducted. Additionally, SEM was used to acquire micro-photographs of the surface morphology of the treated samples. The findings reveal insights into the comparative efficiency of the three dental excavation agents and methods using the laser speckle technique. The speckle parameters extracted from speckle patterns generated by treated teeth provide valuable information for evaluating the performance of the excavation methods. The scanning electron microscopy images also offer detailed visual evidence to support the analysis. This paper demonstrates the potential of the laser speckle technique for assessing the efficiency of dental excavation methods. The objective, non-invasive, and real-time evaluation provided offers advantages over subjective visual assessment and manual measurements.

Cost-effectiveness and cost-benefit analyses of fluoride varnish for caries prevention in Guangxi, China.

OBJECTIVES: The objectives of this study were to evaluate the cost-effectiveness and cost-benefit of fluoride varnish (FV) interventions for preventing caries in the first permanent molars (FPMs) among children in rural areas in Guangxi, China. METHODS: This study constituted a secondary analysis of data from a randomised controlled trial, analysed from a social perspective. A total of 1,335 children aged 6-8 years in remote rural areas of Guangxi were enrolled in this three-year follow-up controlled study. Children in the experimental group (EG) and the control group (CG) received oral health education and were provided with a toothbrush and toothpaste once every six months. Additionally, FV was applied in the EG. A decision tree model was developed, and single-factor and probabilistic sensitivity analyses were conducted. RESULTS: After three years of intervention, the prevalence of caries in the EG was 50.85%, with an average decayed, missing, and filled teeth (DMFT) index score of 1.12, and that in the CG was 59.04%, with a DMFT index score of 1.36. The total cost of caries intervention and postcaries treatment was 42,719.55 USD for the EG and 46,622.13 USD for the CG. The incremental cost-effectiveness ratio (ICER) of the EG was 25.36 USD per caries prevented, and the cost-benefit ratio (CBR) was 1.74 USD benefits per 1 USD cost. The results of the sensitivity analyses showed that the increase in the average DMFT index score was the largest variable affecting the ICER and CBR. CONCLUSIONS: Compared to oral health education alone, a comprehensive intervention combining FV application with oral health education is more cost-effective and beneficial for preventing caries in the FPMs of children living in economically disadvantaged rural areas. These findings could provide a basis for policy-making and clinical choices to improve children's oral health.

Cost-effectiveness of restorative treatments for permanent molars with severe molar incisor hypomineralization: perspectives for the Brazilian public health system.

OBJECTIVES: To undertake a cost-effectiveness analysis of restorative treatments for a first permanent molar with severe molar incisor hypomineralization from the perspective of the Brazilian public system. MATERIALS AND METHODS: Two models were constructed: a one-year decision tree and a ten-year Markov model, each based on a hypothetical cohort of one thousand individuals through Monte Carlo simulation. Eight restorative strategies were evaluated: high viscosity glass ionomer cement (HVGIC); encapsulated GIC; etch and rinse adhesive + composite; self-etch adhesive + composite; preformed stainless steel crown; HVGIC + etch and rinse adhesive + composite; HVGIC + self-etch adhesive + composite, and encapsulated GIC + etch and rinse adhesive + composite. Effectiveness data were sourced from the literature. Micro-costing was applied using 2022 USD market averages with a 5% variation. Incremental cost-effectiveness ratio (ICER), net monetary benefit (%NMB), and the budgetary impact were obtained. RESULTS: Cost-effective treatments included HVGIC (%NMB = 0%/ 0%), encapsulated GIC (%NMB = 19.4%/ 19.7%), and encapsulated GIC + etch and rinse adhesive + composite (%NMB = 23.4%/ 24.5%) at 1 year and 10 years, respectively. The benefit gain of encapsulated GIC + etch and rinse adhesive + composite in relation to encapsulated GIC was small when compared to the cost increase at 1 year (gain of 3.28% and increase of USD 24.26) and 10 years (gain of 4% and increase of USD 15.54). CONCLUSION: Within the horizon and perspective analyzed, the most cost-effective treatment was encapsulated GIC restoration. CLINICAL RELEVANCE: This study can provide information for decision-making.

Fully automated deep learning approach to dental development assessment in panoramic radiographs.

BACKGROUND: Dental development assessment is an important factor in dental age estimation and dental maturity evaluation. This study aimed to develop and evaluate the performance of an automated dental development staging system based on Demirjian's method using deep learning. METHODS: The study included 5133 anonymous panoramic radiographs obtained from the Department of Pediatric Dentistry database at Seoul National University Dental Hospital between 2020 and 2021. The proposed methodology involves a three-step procedure for dental staging: detection, segmentation, and classification. The panoramic data were randomly divided into training and validating sets (8:2), and YOLOv5, U-Net, and EfficientNet were trained and employed for each stage. The models' performance, along with the Grad-CAM analysis of EfficientNet, was evaluated. RESULTS: The mean average precision (mAP) was 0.995 for detection, and the segmentation achieved an accuracy of 0.978. The classification performance showed F1 scores of 69.23, 80.67, 84.97, and 90.81 for the Incisor, Canine, Premolar, and Molar models, respectively. In the Grad-CAM analysis, the classification model focused on the apical portion of the developing tooth, a crucial feature for staging according to Demirjian's method. CONCLUSIONS: These results indicate that the proposed deep learning approach for automated dental staging can serve as a supportive tool for dentists, facilitating rapid and objective dental age estimation and dental maturity evaluation.

Comparing modified USPHS and FDI criteria for the assessment of glass ionomer restorations in primary molars utilising clinical and photographic evaluation.

PURPOSE: To compare the applicability of modified US Public Health Service (USPHS) and FDI criteria for evaluating glass ionomer cement (GIC) restorations in primary posterior teeth through digital image analysis. METHODS: This comparative analytic study was conducted at the Children's Dental Clinic RSKGM FKG UI, involving 40 GIC restorations on lower first primary molars in children aged 4-9 years. After cleaning, the restorations were assessed clinically using modified USPHS and FDI criteria before taking digital images, then the collected images were re-evaluated using both sets of criteria, and the clinical assessment results were compared to the digital image assessment results. RESULTS: Statistical analysis revealed significant differences between the clinical evaluation of GIC restorations in primary teeth and their corresponding digital photographs when using the modified USPHS criteria, and although the use of FDI criteria yielded different results, these differences were not statistically significant. CONCLUSION: The assessment of GIC restorations through digital images aligns more closely with clinical assessments using the FDI criteria compared to the modified USPHS criteria.

Assessment of the trueness of additively manufactured mol3% zirconia crowns at different printing orientations with an industrial and desktop 3D printer compared to subtractive manufacturing.

OBJECTIVES: This study endeavours to investigate the effect of printing orientation on the trueness of additively manufactured molar zirconia crowns. The areal surface roughness and the characteristics of the marginal regions of the crowns were also considered. METHODS: Twelve molar crowns were manufactured at 0°, 45°, and, 90° printing orientations in a Lithoz and AON zirconia printer, respectively. Twelve milled crowns were used as a comparison. Samples were scanned and analysed in metrology software to determine the trueness of the groups. Regions of interest were defined as the margins, intaglio surface and contact points. Areal surface roughness and print layer thickness were further analysed using a confocal laser scanning microscope. RESULTS: The results indicate that there are clear differences between the investigated desktop (AON) and industrial (Lithoz) 3D printer. The 45° Lithoz group is the only sample group showing no significantly different results in trueness for all regions analysed compared to the milled group. Areal surface roughness analysis indicates that the print layers in the marginal regions are within clinically tolerable limits and surface characteristics. CONCLUSIONS: The printing orientation for zirconia crowns is critical to trueness, and differences are evident between different AM apparatuses. Considerations for design and orientation between different apparatuses should therefore be considered when utilising direct additive manufacturing processes. The areal surface roughness of the marginal regions is within acceptable clinical limits for all manufacturing processes and print orientations considered. CLINICAL SIGNIFICANCE: The materials and apparatuses for additive manufacturing of zirconia crowns are now clinically acceptable from the perspective of the trueness of a final crown for critical functional surfaces and areal surface roughness of the marginal regions.

Is the assessment of the mandibular molar danger zone affected by field of view and voxel size in cone beam computed tomography examinations?

OBJECTIVE: To verify if assessment of the danger zone (DZ) in the mesial root of mandibular molars is affected by field of view (FOV) and voxel sizes in cone beam computed tomography (CBCT) scans. STUDY DESIGN: Forty mandibular molars were scanned by micro-computed tomography, creating the reference standard. The teeth were then submitted for CBCT scans with FOVs of 10 × 5.5 cm and 5 × 5.5 cm and voxel sizes of 0.4, 0.2, 0.15, and 0.075 mm3. The smallest dentin thickness in the DZ from the mesiobuccal and mesiolingual canals was measured at 2, 4, and 6 mm apical to the root furcation. Descriptive statistics, paired t-tests, and intraclass correlation coefficients were used for statistical analysis with significance established at P < .05. RESULTS: All CBCT measurements overestimated the DZ dentin thickness (P < .001) compared to the reference standard. The greatest overestimation occurred in the 5 × 5.5 cm FOV with 0.4 mm3 voxels (P = .007). Dentin thickness measured with the 5 × 5.5 cm FOV and 0.075 mm3 voxels was significantly smaller and produced the best ICC value with the reference standard (0.936). CONCLUSIONS: CBCT overestimates the dentin thickness of the DZ regardless of FOV and voxel sizes. The 5 × 5.5 cm FOV showed the best performance with the 0.075 mm3 voxel size, but it performed poorly with 0.4 mm3 voxels.

Measuring Maxillary Posterior Tooth Movement: A Model Assessment using Palatal and Dental Superimposition.

Since the introduction of Invisalign by Align Technology, Inc. in 1999, questions and debates have persisted regarding the precision of Invisalign (clear aligner) therapy, particularly when compared to the use of traditional fixed appliances. This becomes particularly significant in cases involving anteroposterior, vertical, and transverse corrections, where precise comparisons are of paramount importance. To address these inquiries, this study introduces a meticulously devised protocol, placing a primary emphasis on digitally superimposing the movement of maxillary posterior teeth to facilitate accurate analysis. The sample included 25 patients who had completed their first series of Invisalign (clear) aligners. Four maxillary digital models (pre-treatment, post-treatment, ClinCheck-initial, and final models) were digitally superimposed using the palate rugae and dentitions as stable references. A software combination was used for model superimposition and tooth segmentation. Transformation matrices then expressed the differences between the achieved and predicted tooth positions. Thresholds for clinically relevant differences were at ±0.25 mm for linear displacement and ±2° for rotation. Differences were assessed using Hotelling's T-squared tests with Bonferroni correction. The mean differences in rotation (2.036° ± 4.217°) and torque (-2.913° ± 3.263°) were significant statistically and clinically, with p-values of 0.023 and 0.0003 respectively. De-rotation of premolars and torque control for all posterior teeth were less predictable. All mean differences for the linear measurements were statistically and clinically insignificant, except that the first molars seemed slightly (0.256 mm) more intruded than their predicted position. The clear aligner system appears to meet its prediction for most translational tooth movements and mesial-distal tipping in maxillary posterior teeth for non-extraction cases with mild to moderate malocclusions.

Vital root resection with radicular retrograde partial pulpotomy in furcation-involved maxillary molars in patients with periodontitis: Technique description and case series considering clinical and economic aspects.

AIM: Conventional root resection in periodontally compromised furcation-involved maxillary molars requires preceding endodontic treatment and is therefore associated with loss of tooth vitality, higher invasiveness, treatment time and costs, and the risk of endodontic complications. Vital root resection (VRR) could overcome these disadvantages while establishing stable periodontal and endodontic conditions. This case series aimed to introduce the concept of one-stage VRR with radicular retrograde partial pulpotomy (VRRretro). SUMMARY: Seven vital maxillary molars with residual probing pocket depths (PPD) ≥ 6 mm and furcation ≥ class 2 of five patients with stage III/IV periodontitis were treated with VRRretro using mineral trioxide aggregate. Teeth with residual through-and-through furcations were additionally tunnelled. Follow-up up to 2.5 years postoperatively during supportive periodontal care included full periodontal status, percussion and thermal sensitivity testing. Periapical radiographs were obtained to rule out possible periradicular radiolucencies. All seven treated molars were in-situ at an average of 26.84 ± 5.37 months postoperatively and were clinically and radiographically inconspicuous independent of tooth position, the resected root, the need for tunnelling and the restorative status. The mean PPD on the seven treated molars was 4.02 ± 0.85 mm (6-10 mm) preoperatively and 2.62 ± 0.42 mm (3-4 mm) at the last follow-up. Clinical attachment level and bleeding on probing could also be decreased. The teeth showed no mobility over time and furcations class 2 were reduced to class 1 while the tunnelled furcations were accessible with interdental brushes. All molars reacted negatively to percussion and positively to thermal sensitivity testing. KEY LEARNING POINTS: In carefully selected cases considering patient- and tooth-related factors, VRRretro could be a promising treatment option to establish stable periodontal and endodontic conditions in furcation-involved maxillary molars while preserving tooth vitality.

A retrospective longitudinal assessment of artificial intelligence-assisted radiographic prediction of lower third molar eruption.

Prediction of lower third molar eruption is crucial for its timely extraction. Therefore, the primary aim of this study was to investigate the prediction of lower third molar eruption and its uprighting with the assistance of an artificial intelligence (AI) tool. The secondary aim was identifying the incidence of fully erupted lower third molars with hygienic cleansability. In total, 771 patients having two panoramic radiographs were recruited, where the first radiograph was acquired at 8-15 years of age (T1) and the second acquisition was between 16 and 23 years (T2). The predictive model for third molar eruption could not be obtained as few teeth reached full eruption. However, uprighting model at T2 showed that in cases with sufficient retromolar space, an initial angulation of < 32° predicted uprighting. Full eruption was observed for 13.9% of the teeth, and only 1.7% showed hygienic cleansability. The predictions model of third molar uprighting could act as a valuable aid for guiding a clinician with the decision-making process of extracting third molars which fail to erupt in an upright fashion. In addition, a low incidence of fully erupted molars with hygienic cleansability suggest that a clinician might opt for prophylactic extraction.

Clinical and digital assessment of tooth wear.

The aim of this study was to compare the assessment of tooth wear performed on digital models with the one conducted at the clinical examination. Seventy-eight volunteers (29 males and 49 females, age range 20-30 years) with at least 24 teeth, normal oral function, and a neutral transverse relationship were examined. During the clinical examination, dental wear was registered according to the Basic Erosive Wear Examination (BEWE) index. Subsequently, the BEWE index was blindly applied by two examiners on digital models obtained from the volunteers. Data were analyzed using weighted Cohen's kappa coefficient and correlation tests with a confidence interval of 95%. All volunteers showed signs of tooth wear. Anterior teeth showed increased severity of tooth wear than first molars. Early loss of tooth substance could be identified on the digital models, including in areas with challenging direct intraoral visual access. Approximately 50% of the scores based on clinical examination agreed with those based on examination of digital models (k = 0.543, p < 0.01). A moderate, positive correlation was observed between scores registered clinically and on digital models (Spearman's rho = 0.560, p < 0.001). Considering the rather low agreement between the clinical and digital scores, alternatives to using BEWE on digital models are needed.

Tooth Wear Evaluation System 2.0-Evaluation of diagnostic reliability in the assessment of signs and symptoms for tooth wear by non-experts.

BACKGROUND: Tooth wear is a multifactorial condition that manifests through various signs and symptoms. These individual signs and symptoms were described in multiple studies, leading to the inclusion in TWES 2.0 (Tooth Wear Evaluation System 2.0) and the forthcoming DC-TW (Diagnostic Criteria for Tooth Wear). However, a study evaluating their reliability has yet to be conducted. OBJECTIVE: The aim of the study was to examine the reliability in the assessment of 6 signs of pathological tooth wear and 18 clinical signs and symptoms determining aetiology, all of which are included in the TWES 2.0/DC-TW. METHODS: 48 dental students (operators) evaluated patient cases from a patient pool of 14 patients on dental casts and high-resolution intraoral photographs. The agreement between all operators for each sign and symptom was calculated based on ICC (Intraclass Correlation Coefficients). Additionally, the agreement of each operator's evaluation with a predefined sample solution was calculated based on Cohen's kappa. RESULTS: Inter-user agreement ranged from near perfect (0.91) to poor (0.02) for the various pathology signs or aetiology symptoms of tooth wear (mean 0.32). The agreements of the operator's ratings compared to the sample solution resulted in Cohen's kappa from 0.18 to 1 (mean 0.59) for the pathology signs and ranged from 0.02 to 0.51 for the aetiology signs (mean 0.38). CONCLUSIONS: The reliability of the signs and symptoms examined and the ability of individual investigators to correctly identify and assign signs and symptoms varied widely. The current assessment tools for the qualification of tooth wear need further refinement, and examiners need intensive training in tooth wear assessment.

Morphometric Assessment of Alveolar Antral Artery Using Medical Computed Tomography.

This study aimed to investigate the prevalence, diameter, and position of the alveolar antral artery (AAA) in paranasal sinus computed tomography (CT) images and to correlate the location of the AAA with tooth position, the presence of teeth, and residual alveolar bone height (ABH). A retrospective study was conducted at the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital, from November 2016 to October 2021. CT images of 100 maxillary sinuses from 50 patients managed for modified endoscopic sinus surgery and sinus lifting by a single surgeon were selected and obtained from the Infinitt picture archiving and communication system radiology system (Infinitt Healthcare Co., Seoul, Korea). The location of the AAA in the lateral wall of the maxillary sinus was evaluated in correlation with the area of the first and second molars (M1 and M2), the presence of teeth, and the residual ABH. In this study, we found that the intraosseous type is the most common type of AAA. Furthermore, the location and distance of the AAA are significantly affected by tooth position, an edentulous state in the case of the first molar, and residual ABH. Pre-evaluation of the diameter, position, and distance to the AAA using CT images is essential to help prevent hemorrhage. The existence and wide range of the AAA distances based on the tooth position, edentulous state, and residual ABH should be considered even if CT imaging cannot locate the AAA.

Comparative assessment of cleaning efficacy of two exclusive paediatric rotary files in root canals of primary teeth: An in vitro study.

BACKGROUND: Paediatric rotary file systems have recently been developed for primary teeth use. AIM: To study the cleaning efficacies of two paediatric rotary endodontic files, the Prime PedoTM, and the Kedo-SG BlueTM against the standard H files. DESIGN: This in vitro study included 54 freshly extracted primary molars, which were randomised into three groups (n = 18 each) and were prepared using either Kedo-SG BlueTM, Prime PedoTM or hand H files after injecting methylene blue dye into the canals. Pre- and post-operative cone beam computerised tomography (CBCT) was performed to assess change in root canal volumes. Methylene blue dye removal from canals was assessed using stereomicroscopy, and canal cleanliness was examined by scanning electron microscopy (SEM). RESULTS: Both Prime PedoTM and Kedo-SG BlueTM files reduced significantly less dentine when compared with conventional hand filing with Prime PedoTM removing the least amount of dentine. No significant difference was found in median SEM scores among the groups in the cervical, middle and apical thirds of the roots. Stereomicroscopic assessment of root canal cleanliness using dye removal technique shows a statistically significant difference existing between Kedo-SG BlueTM and hand H files groups. CONCLUSION: Prime PedoTM removed the least amount of dentine. Kedo-SG BlueTM performed significantly better than conventional hand filing with H files when the root canal cleanliness was assessed.

Optical impressions assessment for overlay restorations with rubber dam: A clinical trial.

OBJECTIVE: The possibility of making impressions of teeth prepared with a rubber dam in place has been proposed; however, this requires trimming and rescanning the mesh, which has been described as a cause of accuracy loss. This study aims to clinically determine whether overlay restorations obtained from a scan with a rubber dam in place have equivalent marginal fit, contact points, and occlusal fit to the same type of restorations obtained from a scan without a rubber dam. MATERIAL AND METHODS: Thirty patients who underwent overlay restoration of a molar with at least one neighbouring tooth were selected. After tooth preparation, two scans were performed: one without a rubber dam and the other with a rubber dam. Restorations were randomly created from one scan or another. The marginal fit, interproximal contact points, and occlusal fit were evaluated clinically. Two meshes, with and without rubber dams, were also compared. RESULTS: No significant differences were observed in the clinical evaluation of the overlays made of the two meshes. The trueness of the mesh from the impression made with a rubber dam with respect to the mesh without a rubber dam was about 40 µm in the critical areas of the preparation (margins, intaglio, and interproximal contact points). CONCLUSIONS: The results of this study show that under the conditions performed and with the equipment used, there are no significant clinical differences between overlay restorations made from a scan with a rubber dam and those made from a scan without a rubber dam. CLINICAL SIGNIFICANCE: Scanning with a rubber dam in place may be a valid option for certain types of restorations under certain clinical conditions.

Preinterventional Third-Molar Assessment Using Robust Machine Learning.

Machine learning (ML) models, especially deep neural networks, are increasingly being used for the analysis of medical images and as a supporting tool for clinical decision-making. In this study, we propose an artificial intelligence system to facilitate dental decision-making for the removal of mandibular third molars (M3M) based on 2-dimensional orthopantograms and the risk assessment of such a procedure. A total of 4,516 panoramic radiographic images collected at the Center of Dental Medicine at the University of Zurich, Switzerland, were used for training the ML model. After image preparation and preprocessing, a spatially dependent U-Net was employed to detect and retrieve the region of the M3M and inferior alveolar nerve (IAN). Image patches identified to contain a M3M were automatically processed by a deep neural network for the classification of M3M superimposition over the IAN (task 1) and M3M root development (task 2). A control evaluation set of 120 images, collected from a different data source than the training data and labeled by 5 dental practitioners, was leveraged to reliably evaluate model performance. By 10-fold cross-validation, we achieved accuracy values of 0.94 and 0.93 for the M3M-IAN superimposition task and the M3M root development task, respectively, and accuracies of 0.9 and 0.87 when evaluated on the control data set, using a ResNet-101 trained in a semisupervised fashion. Matthew's correlation coefficient values of 0.82 and 0.75 for task 1 and task 2, evaluated on the control data set, indicate robust generalization of our model. Depending on the different label combinations of task 1 and task 2, we propose a diagnostic table that suggests whether additional imaging via 3-dimensional cone beam tomography is advisable. Ultimately, computer-aided decision-making tools benefit clinical practice by enabling efficient and risk-reduced decision-making and by supporting less experienced practitioners before the surgical removal of the M3M.