Search Results (472)

Background and Clinical Significance: Traumatic dental injuries, particularly complicated crown fractures of permanent incisors, are common in adolescents, with maxillary central incisors most frequently affected due to their prominent position. These injuries, often resulting from sports or accidents, require prompt management to prevent complications such as pulp necrosis or infection, which can compromise long-term prognosis. Fragment reattachment offers a conservative, esthetically favorable approach when the fractured segment is intact, with outcomes comparable to composite restorations. This case report underscores the importance of timely intervention and advanced restorative techniques in pediatric dentistry. Case Presentation: A 16-year-old male presented with a complicated crown fracture of the upper left central incisor sustained during a soccer game. The fracture extended subgingivally with pulp exposure. The patient preserved the fragment in saline. Treatment involved fragment reattachment using a dentin bonding agent and flowable composite resin, followed by single-visit root canal therapy due to delayed presentation (48 h). A glass fiber post was placed to reinforce the restoration due to significant coronal loss. Three years of follow-up visits (1, 3, 6, 12, 24, and 36 months) revealed no clinical or radiographic complications, with the tooth remaining asymptomatic and functional. Conclusions: This case underscores the effectiveness of fragment reattachment when combined with meticulous technique and long-term monitoring. Full article

The aim of this study was to compare the forces and moments exerted by thermoformed aligners (TFMs) and direct printed aligners (DPAs) on the maxillary left central incisor (21) and adjacent teeth (11, 22) during lingual bodily movement of tooth 21. Methods: An in vitro setup was used to quantify forces and moments on three incisors, which were segmented and fixed onto multi-axis force/moment transducers. TFM were fabricated using 0.76 mm-thick single-layer PET-G foils (ATMOS; American Orthodontics, Sheboygan, WI, USA) and multi-layer TPU foils (Zendura FLX; Bay Materials LLC, Fremont, CA, USA). DPAs were fabricated using TC-85 photopolymer resin (Graphy Inc., Seoul, Republic of Korea). Tooth 21 was planned for bodily displacement by 0.25 mm and 0.50 mm, and six force and moment components were measured on it and the adjacent teeth. Results: TC-85 generated lower forces and moments with fewer unintended forces and moments on the three teeth. TC-85 exerted 0.99 N and 1.53 N of mean lingual force on tooth 21 for 0.25 mm and 0.50 mm activations, respectively; ATMOS produced 3.82 N and 7.70 N, and Zendura FLX produced 3.00 N and 8.23 N of mean lingual force for the same activations, respectively. Bodily movement could not be achieved. Conclusions: The force systems generated by clear aligners are complex and unpredictable. DPA using TC-85 produced lower, more physiological force levels with fewer side effects, which may increase the predictability of tooth movement and enhance treatment outcome. The force levels generated by TFM were considered excessive and not physiologically compatible. Full article

Background: Osteodysplastic syndromes comprise a very diverse group of clinically and genetically heterogeneous disorders characterized by defects in bone and connective tissue development, as well as in bone density. Here, we report the case of a 48-year-old female with a complex medical history characterized by bone dysplasia, hyperostosis, and partial tooth agenesis. Methods: Genetic testing was performed using WES analysis and Sanger sequencing. Molecular modeling analysis and dynamics simulation explored the impact of detected pathogenic variants. Results: The genetic analysis detected multiple pathogenic variants in genes CREB3L1, SLCO2A1, SFRP4, LRP5, and LRP6, each of which has been associated with rare osteodysplastic syndromes. The patient was homozygous for the same rare alleles associated with three of the identified autosomal recessive disorders osteogenesis imperfecta type XVI, primary hypertrophic osteoarthropathy, and metaphyseal dysplasia Pyle type. She also had a variant linked to autosomal dominant endosteal hyperostosis and a variant previously associated with increased risk of osteoporosis and bone fractures. Two of the detected variants are predicted to cause abnormal splicing, while molecular modeling and dynamics simulations analysis suggest that the other three variants probably confer altered local secondary structure and flexibility that may have functionally devastating consequences. Conclusions: Our case highlights the rare coexistence of multiple osteodysplastic syndromes in a single patient that may complicate differential diagnosis. Furthermore, this case emphasizes the necessity for early genetic investigation of such complex cases with overlying phenotypic traits, followed by genetic counseling, facilitating orchestration of clinical interventions and allowing prevention and/or prompt management of manifestations. Full article

In precision cotton seeding, the toothed-disk precision seeder often experiences issues with missed seeding and multiple seeding. To promptly detect and address these abnormal seeding conditions, this study develops a modular photoelectric sensing monitoring system. Initially, the monitoring time window is divided using the capacitance sensing signal between two seed drop ports. Concurrently, a photoelectric monitoring circuit is designed to convert the time when seeds block the sensor into a level signal. Subsequently, threshold segmentation is performed on the time when seeds block the photoelectric path under different seeding states. The proposed spatiotemporal joint counting algorithm identifies, in real time, the threshold type of the photoelectric sensor’s output signal within the current monitoring time window, enabling the differentiation of seeding states and the recording of data. Additionally, an STM32 micro-controller serves as the core of the signal acquisition circuit, sending collected data to the PC terminal via serial port communication. The graphical display interface, designed with LVGL (Light and Versatile Graphics Library), updates the seeding monitoring information in real time. Compared to photoelectric monitoring algorithms that detect seed pickup at the seed metering disc, the monitoring node in this study is positioned posteriorly within the seed guide chamber. Consequently, the differentiation between single seeding and multiple seeding is achieved with greater accuracy by the spatiotemporal joint counting algorithm, thereby enhancing the monitoring precision of the system. Field test results indicate that the system’s average accuracy for single-seeding monitoring is 97.30%, for missed-seeding monitoring is 96.48%, and for multiple-seeding monitoring is 96.47%. The average probability of system misjudgment is 3.25%. These outcomes suggest that the proposed modular photoelectric sensing monitoring system can meet the monitoring requirements of precision cotton seeding at various seeding speeds. Full article

This paper investigates the dependencies between the design parameters of the armature (stator) winding of a high-speed PMSM machine and the electrical losses in its windings resulting from eddy currents. In addition, the factors accounting for the occurrence of parasitic circulating currents, whose presence in the phase windings is associated with the design specificity, are analyzed. Quantitative analysis is carried out by the application of a newly developed mathematical model for the calculation of fundamental and additional losses in a multi-turn coil enclosed in the slots of a ferromagnetic core. The analysis takes into account the actual design of the slot and the conductor, the variable arrangement of individual conductors in the slot, the core saturation and the presence of the excitation field—to represent the main factors that affect the process of additional losses in the slot of the electric machine. The verification of the mathematical model developed in this study was carried out by comparing the distribution of power losses in the slot section of the coil, consisting of several elementary conductors connected in parallel and located in a rectangular open slot, with an identical distribution derived on the basis of an analytical method from the classical circuit theory. For the purpose of confirming the results and conclusions derived from simulation studies, a number of physical experiments were carried out, consisting in determining the power losses in multi-turn coils of different designs. Recommendations have been developed to minimize additional losses by optimizing the arrangement of conductors within the slot, selecting the appropriate cross-sectional size of a single conductor and the saturation level of the tooth zone. Full article

Tooth wear is a growing oral health concern with implications for function, esthetics, and psychological well-being, ultimately affecting oral health-related quality of life (OHRQoL). While clinical indices assess tooth wear severity, they fail to capture patient-reported outcomes (PROs) and patient-reported outcome measures (PROMs). This narrative review aims to identify and synthesize the use of PROs and PROMs used in adults with tooth wear and to map their assessed domains against the Wilson and Cleary model of health outcomes, highlighting gaps and guiding the development of condition-specific instruments. A comprehensive search of the literature was conducted across PubMed, MEDLINE, and Embase. Studies involving PROMs in adults with tooth wear were included. Extracted data encompassed psychometric properties and domains assessed. PROMs such as the OHIP, OES, OIDP, and QMFQ have been frequently used, focusing on functional limitation, esthetic perception, and psychological distress. However, no single instrument comprehensively addresses all relevant domains of the Wilson and Cleary model. Moreover, variation in tools and constructs limits comparability across studies and clinical settings. Existing PROMs capture only partial aspects of the patient experience related to tooth wear. When mapping these instruments to a validated theoretical model, significant gaps become evident, especially in terms of general health perceptions and overall quality of life metrics. To improve the evaluation and management of tooth wear in clinical settings, it is essential to create a condition-specific PROM based on a solid conceptual framework. Full article

Background: Digital dental photography is increasingly essential for documentation and smile design. This study aimed to compare the linear measurement accuracy of various smartphones and a Digital Single-Lens Reflex (DSLR) camera against digital models obtained by intraoral and desktop scanners. Methods: Tooth height and width from six different casts were measured and compared using images acquired with a Canon EOS 250D DSLR, six smartphone models (iPhone 13, iPhone 15, Samsung Galaxy S22 Ultra, Samsung Galaxy S23 Ultra, Samsung Galaxy S24, and Vivo T2), and digital scans obtained from the Helios 500 intraoral scanner and the Ceramill Map 600 desktop scanner. All image measurements were performed using ImageJ software (National Institutes of Health, Bethesda, MD, USA), and statistical analysis was conducted using one-way analysis of variance (ANOVA) with Tukey’s post hoc test (α = 0.05). Results: The results showed no significant differences in measurements across most imaging methods (p > 0.05), except for the Vivo T2, which showed a significant deviation (p < 0.05). The other smartphones produced measurements comparable to those of the DSLR, even at distances as close as 16 cm. Conclusions: These findings preliminary support the clinical use of smartphones for accurate dental documentation and two-dimensional smile design, including the posterior areas, and challenge the previously recommended 24 cm minimum distance for mobile dental photography (MDP). This provides clinicians with a simplified and accessible alternative for high-accuracy dental imaging, advancing the everyday use of MDP in clinical practice. Full article

Background: In modern dentistry, alveolar socket preservation after tooth extraction plays a critical role in maintaining the alveolar ridge for future dental implants. This retrospective clinical study evaluated bone-level changes 15 years after immediate implant placement, coupled with alveolar ridge preservation. Methods: Fifty non-smoking patients aged 25 to 75 (30 males and 20 females) who underwent single-implant rehabilitation in both anterior and posterior regions of the upper and lower jaws were included. The study examined bone levels and implant survival over time, using standardized intraoral radiographs at 1, 5, and 15 years post-loading. Implants were placed immediately after atraumatic extraction, and the residual gap was grafted with bovine hydroxyapatite and covered with a collagen membrane. The primary outcome was bone-level stability, while secondary outcomes included implant failure. No temporary crowns or removable dentures were provided during healing. Radiographs were digitized for detailed analysis. Results: The results for 50 patients with immediate implant placement showed that bone-resorption levels were significantly higher in the upper jaw than in the lower jaw. Conclusions: Posterior implants exhibited greater bone loss than anterior implants, particularly at 1 year and 15 years, while no implant failures occurred. Full article

Background/Objectives: Smile esthetics are a crucial aspect of facial attractiveness, playing a central role in social interactions. Dental students’ perception of smiling esthetics may evolve as they progress through their education and clinical exposure. This study aimed to investigate the influence of educational level on dental students’ perception of altered smile esthetics. Methods: A cross-sectional study was conducted among 410 undergraduate dental students across five academic years at the National and Kapodistrian University of Athens. Participants evaluated 22 digitally altered smile images, including single and combined esthetic discrepancies, using a visual analog scale (VAS). Perceived attractiveness scores were analyzed in relation to academic year, gender, and specific types of smile alterations. Results: The perception of smile attractiveness varied significantly across academic years for certain esthetic discrepancies, including central incisor length mismatch, midline diastema, and open gingival embrasures (p < 0.05). Clinical-year students (years 4–5) demonstrated a more critical assessment compared to preclinical students. Female students exhibited greater sensitivity to specific discrepancies, including fluorosis and reduced tooth lightness. The combination of a midline diastema, a gummy smile, and reduced lightness received the lowest attractiveness scores across all groups. Conclusions: The perception of altered smile esthetics among undergraduate dental students evolves throughout their education, although this progression does not follow a linear trajectory. Dental education appears to influence the perception of specific smile esthetic discrepancies, reflecting a selective influence on features. Clinical training appears to be a critical parameter of dental education, influencing the perception of smiling esthetics. Full article

Background/Objectives: Dental implants represent a viable solution for replacing missing teeth; however, multiple disconnections and reconnections of intermediate abutments contribute to the apical displacement of the peri-implant connective tissue barrier, resulting in additional marginal bone loss. To the best of our knowledge, no definitive customized abutments currently exist that are specifically designed according to the morphology of the tooth to be replaced and its position within the dental arch, allowing for digital planning within the prosthetic implant design and insertion during the surgical procedure without subsequent disconnection. Methods: The First Biological Respect (FR) technique, described in this case report, enables the digital planning not only of the implant but also of the patented FR customized-shaped, definitive abutment and associated FR prosthetic components. The FR technique was applied to a case involving an immediate post-extraction implant in position 12. Results: With the limitations of a case report, the application of the FR protocol demonstrated stable crestal bone levels at the 1-year follow-up. Additionally, soft tissue volume was maintained at 6 months, reflecting the accuracy of the customized prosthetic components in supporting, guiding, and protecting peri-implant soft tissues. At the 1-year follow-up, an increase in soft tissue volume was observed, likely attributable to tissue maturation and the further customization of the definitive prosthetic elements. Conclusions: The FR technique represents a viable therapeutic alternative that, through its patented, fully customized components, allows for the digital planning of the implant, as well as the customized definitive abutment, coping, provisional, and final prosthetic framework. This facilitates a single-stage surgical and prosthetic approach. By eliminating the need for repeated abutment disconnections, this method supports the long-term stability of both hard and soft peri-implant tissues while also reducing overall treatment time for both clinician and patient. Further studies involving larger patient cohorts are necessary to validate this protocol. Full article

Aim: This in vitro study aimed to evaluate the adhesive performance of zirconia and lithium disilicate Maryland cantilever restorations on prepared and non-prepared anterior abutment teeth. While conventional clinical protocols involve abutment tooth preparation, no-preparation (no-prep) restorations have emerged as a viable, minimally invasive alternative. This study compared the adhesion fracture resistance (N) of zirconia restorations on non-prepared enamel surfaces with those on prepared surfaces exposing the dentin. Additionally, the zirconia restorations were compared with lithium disilicate Maryland cantilever restorations, a more common yet costly alternative. Materials and Methods: Forty extracted anterior teeth were allocated into four groups based on preparation type (prepared vs. non-prepared) and material (zirconia vs. lithium disilicate). Each group received cantilevered single-unit FPDs fabricated via CAD/CAM and adhesively cemented using Variolink^® Esthetic DC. Standardized loading was applied using a universal testing machine, and the fracture resistance was recorded. Results: The fracture resistance ranged from 190 to 447 N in the zirconia groups and from 219 to 412 N in the lithium disilicate groups. When comparing all the zirconia versus all the lithium disilicate ceramic restorations, regardless of tooth preparation, no statistically significant difference was found (p = 0.752). However, the non-prepared restorations exhibited significantly higher fracture resistance than their prepared counterparts (p = 0.004 for zirconia; p = 0.012 for lithium disilicate ceramic). All the failures were attributed to tooth fracture, except one zirconia restoration, with no debonding observed. Conclusions: Both zirconia and lithium disilicate Maryland cantilever restorations demonstrated reliable adhesive performance when bonded using appropriate surface conditioning and adhesive protocols. Interestingly, the non-prepared designs exhibited higher fracture resistance than the prepared abutments, highlighting their potential advantage in minimally invasive restorative dentistry. Zirconia Maryland bridges, in particular, represent a cost-effective and mechanically resilient option for anterior single-tooth replacement. Full article

Background: Tooth loss significantly impacts the quality of life for adults. Inferior alveolar nerve (IAN) repositioning has garnered interest as a treatment for facilitating dental implant placement in the severely atrophic posterior mandible. However, there remains a need for standardization and classification of these techniques to improve outcomes. This study aims to propose a new clinical classification system for IAN repositioning procedures based on anatomical and procedural parameters. Methods: This study retrospectively analyzed preoperative radiographic records and surgical procedure documents over a 15-year period (2008–2023) for patients who underwent implant placement combined with IAN repositioning in the posterior atrophic mandible. Cases were classified into four categories according to bone availability, nerve location, and type of surgical intervention. Results: The study analyzed 142 edentulous posterior mandibles in 105 patients (77 women, 28 men; age range: 20–75). The cases were divided into four categories: Category 1 (58 patients, 78 sites), treated with one surgery; Category 2 (15 patients, 15 sites), treated in two stages; Category 3 (20 patients, 25 sites); and Category 4 (12 patients, 24 sites), with Categories 3 and 4 treated in a single surgery. Across all 132 sites, 411 dental implants were placed and restored with implant-supported fixed prostheses. Conclusions: This proposed classification provides a structured systematic framework for assessing and planning IAN repositioning procedures. It facilitates better diagnosis, treatment planning, and prediction of surgical stages in patients needing IAN repositioning for dental implant placement. Full article

Objectives: To introduce a novel method for apical lesion sampling using a protected paper point device and to evaluate its effectiveness and robustness during the sampling process in vitro. Methods: A prototype for apical sample collection was developed as an adaptation of the Micro-Apical Placement System—the device features a highly tapered screw head with a thin, hollow, stainless-steel tube and an internal wire piston. Standardized 5 mm paper points (ISO 10; PD Dental, Switzerland) served as carrier material. The prototype was tested using 30 × 3D-printed, single-rooted tooth models inoculated using two bacterial strains (Staphylococcus epidermidis and Escherichia coli) to simulate apical and intraradicular bacterial infections, respectively. The sampling process involved collecting and analyzing samples at specific timepoints, focusing on the presence or absence of E. coli contamination. Following sample collection, cultural detection of bacterial presence was performed by incubating the samples on agar plates to confirm the presence of E. coli. Samples were collected as follows: S0 (sterility control of the prototype), P0 (sterility control of the tooth model), P1 (apical sample collected with the CAPS (controlled apical sampling) device, and P2 (contamination control sample to check for the presence of E. coli inside the root canal). Results: Handling of the CAPS prototype was straightforward and reproducible. No loss of paper points or complications were observed during sample collection. All sterility samples (P0, S0) were negative for tested microorganisms, confirming the sterility of the setup. P2 samples confirmed the presence of E. coli in the root canal in all trials. The P1 samples were free from contamination in 86.67% of trials. Conclusions: The CAPS method for apical sampling demonstrated advances in the successful and precise sample collection of apically located S. epidermidis and will be a useful tool for endodontic microbiological analysis. Its user-friendly design and consistent performance highlight its potential for clinical application, contributing to more accurate microbial diagnostics and later patient-specific therapeutic approaches in endodontic treatments. Full article

Objectives: The aim of this study is to investigate how Adaptive Torque Control motion influences the shaping efficiency of Neolix EDMax (Neolix SAS, Évron, France) and its ability to reach working length with or without a pre-existing glide path. Methods: A total of 90 endo training blocks with an S-shape curvature were divided into three groups based on the kinematics and preparation phase: the control group, where the Neolix EDMax (Neolix SAS, Évron, France) was used for shaping after a glide path was established; the no glide path group, where the Neolix EDMax (Neolix SAS, Évron, France) was used for shaping without a glide path; and the Adaptive Torque Control group, where the Neolix EDMax (Neolix SAS, Évron, France) was used for shaping without a glide path but in an Adaptive Torque Control motion. The time for shaping, the instrument passes, and the ability to reach working length were recorded and analyzed using a one-way Anova and Tukey’s HSD post hoc test. Results: Establishing a glide path helped the shaping file to reach working length faster and in fewer passes when compared with the no glide path group, but the Adaptive Torque Control group was able to perform even better than the control group despite not having a pre-established glide path. Conclusions: The Adaptive Torque Control motion on continuous rotation instruments does impact their performance. Combining the efficiency of continuous rotation and the safety of reciprocation, this type of motion had a significant effect on the ability to shape the simulated root canal even in the presence of a double curvature and without a pre-established glide path. Full article

Background: Bone resorption following tooth loss poses significant challenges for dental implant success. Guided bone regeneration (GBR) techniques, particularly in vertically deficient ridges, often require complex procedures and soft tissue management. This case report introduces a modified occlusive barrier with a window, combined with tricalcium phosphate, to address these challenges. Methods: A 26-year-old female with significant bone loss in the mandibular anterior region underwent GBR using a digitally designed titanium occlusive barrier. The barrier was fabricated using CAD/CAM technology and secured with screws. A blood clot mixed with tricalcium phosphate was used to promote bone regeneration. Postoperative care included regular irrigation, de-epithelialization, and follow-up over six months. Implant placement and histological analysis were performed to evaluate outcomes. Case Presentation: The patient achieved 8.8 mm of vertical and 7.6 mm of horizontal bone regeneration. Histological analysis confirmed the presence of mature, mineralized bone, and keratinized gingiva. The implant was successfully placed, and a fixed prosthesis was restored after four months, with stable results at a three-year follow-up. Conclusion: This technique demonstrates effective bone and soft tissue regeneration in a single procedure, eliminating the need for autologous bone grafts and secondary surgeries. The use of a digitally designed occlusive barrier offers precision, reduces morbidity, and simplifies the surgical process, suggesting a promising advancement in GBR. Further studies are needed to validate these findings. Full article