In-vitro comparison of fracture resistance of CAD/CAM porcelain restorations for endodontically treated molars.

BACKGROUND: This study evaluates the fracture strength and patterns of feldspathic porcelain restorations made using CAD/CAM technology for lower first molars with extensive crown destruction. The restorations include post-core and full-contour crown, composite resin core and full-contour crown, and endocrown. This research provides insights into effective restorative options to address tooth fracture risk, supporting minimally invasive procedures and CAD/CAM integration in dental practices. METHODS: This study utilized 80 permanent mandibular first molars, which were divided into four groups: Group I (Post-Core-Full-contour crown), Group II (Core- Full-contour crown), Group III (Endocrown), and Group IV (Control). Root canal treatment was performed on all samples except for the control group. Following access cavity preparation, restorations for each tooth were fabricated using the CAD/CAM system and cemented with resin cement. The specimens were embedded in acrylic blocks. After undergoing thermomechanical aging, the samples were subjected to fracture resistance testing using a universal testing machine, which applied force until fracture occurred. The fracture patterns were subsequently analyzed, and the data were statistically evaluated using the Kruskal-Wallis and Chi-Square tests (p < 0.05). RESULTS: A significant difference in fracture values under axial forces was observed (p < 0.05). The control group had the highest fracture strength (1830 ± 277 N), while the Core- full-contour crown group showed the lowest (1532 ± 371 N). Failure types varied significantly among the groups (χ2 = 26.886, df = 9, p = 0.001). The most common failure type was Type-2 (33.75%), characterized by restorable fractures, while Type-3 fractures, unrestorable, were the least common (12.5%). CONCLUSIONS: The findings underscore the significance of technological advancements in CAD/CAM for effectively restoring endodontically treated teeth with extensive crown damage. This study contributes valuable insights, emphasizing the clinical relevance of selecting appropriate restorative options to mitigate the risk of tooth fracture associated with coronal restoration failures.

Fabrication of Zirconia Ceramic Dental Crowns by Digital Light Processing: Effects of the Process on Physical Properties and Microstructure.

Highly dense zirconia ceramic dental crowns were successfully fabricated by a digital light processing (DLP) additive manufacturing technique. The effects of slurry solid content and exposure density on printing accuracy, curing depth, shrinkage rate, and relative density were evaluated. For the slurry with a solid content of 80 wt%, the curing depth achieved 40 µm with minimal overgrowth under an exposure intensity of 16.5 mW/cm2. Solid content and sintering temperature had remarkable effects on physical properties and microstructure. Higher solid content resulted in better structural integrity, higher relative density, and denser microstructure. Compressive strength, Vickers hardness, fracture toughness, and wear resistance significantly increase with lifting solid content, reaching values of 677 MPa, 12.62 GPa, 6.3 MPa·m1/2, and 1.5 mg/min, respectively, for 1500°C sintered zirconia dental crowns printed from a slurry with 80 wt% solid content. DLP is deemed a promising technology for the fabrication of zirconia ceramic dental crowns for tooth repair.

Plain language summary: 5-year results from the CROWN study of lorlatinib vs crizotinib in non-small-cell lung cancer.

WHAT IS THIS STUDY ABOUT?: This is a summary of the results of an ongoing study called CROWN. In the CROWN study, researchers looked at the effects of two medicines called lorlatinib (Lorbrena) and crizotinib (Xalkori) for people with advanced non-small cell lung cancer (NSCLC) who had not been treated yet. Everyone in the study had changes in a gene called anaplastic lymphoma kinase, or ALK, in their cancer cells. The changes in the ALK gene can make cancer grow. This analysis looked at how well lorlatinib and crizotinib worked and their side effects in people with advanced ALK-positive NSCLC after 5 years. WHAT DID THIS STUDY FIND?: After observing people for an average of 5 years, researchers found that more people who took lorlatinib were still alive without their cancer getting worse than the people who took crizotinib. At 5 years, the probability of being alive without their cancer getting worse was 60% in people who took lorlatinib compared with 8% in people who took crizotinib. Fewer people who took lorlatinib had their cancer spread within or to the brain than the people who took crizotinib. In more than half of the people who took lorlatinib, tumors that had spread to the brain did not get worse, and no new tumors spread to the brain after 5 years. In contrast, in about half of the people who took crizotinib, tumors that had spread to the brain got worse or new tumors spread to the brain after 16.4 months. More people who took lorlatinib (115 out of 149, or 77%) had severe or life-threatening side effects than people who took crizotinib (81 out of 142, or 57%). These side effects were like the ones reported in the earlier 3-year analysis. WHAT DO THE FINDINGS OF THE STUDY MEAN?: The 5-year results from the CROWN study showed that more people who took lorlatinib continued to benefit from their treatment than those who took crizotinib. The 5-year benefit of lorlatinib in people with ALK-positive NSCLC has never been seen before.Clinical Trial Registration: NCT03052608 (Phase 3 CROWN study) (ClinicalTrials.gov).

Surgical Extrusion of Three Premolars to Re-establish the Biological Width: Case Series.

AIM: This case series was to describe the use of surgical extrusion for three different cases as a technique to re-establish the biological width in patients with insufficient crown height. BACKGROUND: Surgical extrusion serves as an important means to reestablishing a proper biological width. Such method provides an excellent alternative for the restoration of teeth with insufficient ferrule and ensuring a suitable dental restoration. CASES DESCRIPTIONS: This case series describes the management of three different cases with compromised teeth #25, #35, and #44, respectively. The approach involved the surgical extrusion of the compromised sites from subgingival to supragingival and the splinting of the teeth using a semi-rigid splint. A successful prognosis was observed on follow-up visits. CONCLUSION: This technique is a good alternative for general practitioners because of its easy implementation and time efficiency. In addition, the method requires less equipment and provides for adequate space for the re-establishment of biological width. CLINICAL SIGNIFICANCE: Such technique can re-establish a healthy biological width, the existing occlusion can be maintained without alterations, and it demonstrated the suitability of surgical extrusion technique in such clinical situations. Case selection is equally important. Cases with single-rooted teeth with fractures or caries in proximity to the marginal bone level without vertical root fractures generally provide positive outcomes on providing this treatment. How to cite this article: Boreak N, Al Moaleem MM, Zain AA, et al. Surgical Extrusion of Three Premolars to Re-establish the Biological Width: Case Series. J Contemp Dent Pract 2024;25(6):593-598.

Influence of light-polymerizing units and zirconia on the physical, chemical and biological properties of self-adhesive resin cements.

BACKGROUND: Self-adhesive resin cements (SARCs) are widely used for fixed prostheses, but incomplete cleaning near the gingival margin can cause inflammation. However, the factors influencing cement properties and the biological response of gingival fibroblasts to cement eluates are not well understood. This study examines the impact of two light-polymerizing units (LPUs) on the physical and chemical properties of two SARCs under simulated clinical conditions, as well as the subsequent response of human gingival fibroblasts (hGFs) to these eluates. METHODS: Dental cement discs of SARCs were polymerized using Kerr DemiPlus and 3 M Elipar DeepCure-S LED LPUs with or without a 2-mm thick zirconia screen. Physical properties (microhardness, surface roughness, residual monomers) were evaluated. hGFs' cell viability, wound healing potency, and gene expression were assessed. RESULTS: Both Maxcem and RelyX exhibited reduced microhardness and increased surface roughness when polymerized through zirconia or with DemiPlus LPU. Higher residual monomers (HEMA and GDMA in Maxcem; TEGDMA in RelyX) concentration was observed with DemiPlus and zirconia polymerization. Maxcem polymerized with DemiPlus exhibited lower cell viability, impaired healing, and altered gene expression in hGFs compared to those polymerized with Elipar LPU. Gene expression changes included downregulated NRF2 and HO-1 and upregulated CCR-3. CONCLUSIONS: Light-polymerizing Maxcem through zirconia with DemiPlus LPU compromised SARCs' properties, leading to higher residual monomers and negatively impacting hGFs' viability, healing, and gene expression. Careful material selection and polymerization techniques are crucial to minimize adverse effects on surrounding tissues. CLINICAL SIGNIFICANCE: Clinicians should exercise caution when using LPUs and SARCs, especially when polymerizing through zirconia. This will help optimize the physical and chemical properties of SARCs and minimize potential adverse effects on the surrounding gingival soft tissues.

A feasibility study on the use of an intraoral optical coherence tomography system for scanning the subgingival finish line for the fabrication of zirconia crowns: An evaluation of the marginal and internal fit.

OBJECTIVES: This study aimed to evaluate the marginal and internal fit of zirconia crowns were fabricated using scan data from an intraoral optical coherence tomography (OCT) scanner and an intraoral scanner (IOS) for scanning the subgingival finish line. METHODS: An extracted maxillary left central incisor was prepared for a zirconia crown. The prepared tooth was placed in artificial gingiva, created using silicone with a refractive index similar to that of the tooth, ensuring a subgingival depth of 0.50 to 0.70 mm from the labial finish line. Scanning data were obtained from four types of models as follows. (1) CAD reference model (CRM) excluding the gingiva and scanned using a laboratory scanner. (2) IOS group excluding the gingiva (IOS only, IOSO group). (3) IOS group with scanned attached artificial (IOS with gingiva, IOSG group). (4) OCT post-processed data of the subgingival finish line and IOSG data (OCT group). Zirconia crowns were fabricated based on these data, and their marginal and internal fit were evaluated using the silicone replica technique. Statistical analyses were conducted using one-way and two-way ANOVA (α = 0.05). RESULTS: The OCT group exhibited a significantly smaller marginal gap than the IOSG group (P < 0.05). The marginal fit of the OCT group did not significantly differ from that of the CRM group (P > 0.05). The IOSG group exhibited a significantly larger chamfer gap, while both the IOSG and OCT groups had significantly larger axial gaps. Furthermore, the OCT group showed a significantly larger incisal gap (P < 0.05). CONCLUSIONS: An intraoral OCT system can enhance the fabrication accuracy of zirconia crowns by achieving superior marginal fit for crowns with subgingival finish lines. CLINICAL SIGNIFICANCE: The use of an IOS for subgingival finish lines without gingival displacement cords may result in a suboptimal marginal fit. However, integrating OCT technology can effectively address this issue, leading to improved clinical outcomes.

Arabidopsis F-box proteins D5BF1 and D5BF2 negatively regulate Agrobacterium-mediated transformation and tumorigenesis.

The pathogen Agrobacterium tumefaciens is known for causing crown gall tumours in plants. However, it has also been harnessed as a valuable tool for plant genetic transformation. Apart from the T-DNA, Agrobacterium also delivers at least five virulence proteins into the host plant cells, which are required for an efficient infection. One of these virulence proteins is VirD5. F-box proteins, encoded in the host plant genome or the Ti plasmid, and the ubiquitin/26S proteasome system (UPS) also play an important role in facilitating Agrobacterium infection. Our study identified two Arabidopsis F-box proteins, D5BF1 and D5BF2, that bind VirD5 and facilitate its degradation via the UPS. Additionally, we found that Agrobacterium partially suppresses the expression of D5BF1 and D5BF2. Lastly, stable transformation and tumorigenesis efficiency assays revealed that D5BF1 and D5BF2 negatively regulate the Agrobacterium infection process, showing that the plant F-box proteins and UPS play a role in defending against Agrobacterium infection.

Automated Crack Detection in Monolithic Zirconia Crowns Using Acoustic Emission and Deep Learning Techniques.

Monolithic zirconia (MZ) crowns are widely utilized in dental restorations, particularly for substantial tooth structure loss. Inspection, tactile, and radiographic examinations can be time-consuming and error-prone, which may delay diagnosis. Consequently, an objective, automatic, and reliable process is required for identifying dental crown defects. This study aimed to explore the potential of transforming acoustic emission (AE) signals to continuous wavelet transform (CWT), combined with Conventional Neural Network (CNN) to assist in crack detection. A new CNN image segmentation model, based on multi-class semantic segmentation using Inception-ResNet-v2, was developed. Real-time detection of AE signals under loads, which induce cracking, provided significant insights into crack formation in MZ crowns. Pencil lead breaking (PLB) was used to simulate crack propagation. The CWT and CNN models were used to automate the crack classification process. The Inception-ResNet-v2 architecture with transfer learning categorized the cracks in MZ crowns into five groups: labial, palatal, incisal, left, and right. After 2000 epochs, with a learning rate of 0.0001, the model achieved an accuracy of 99.4667%, demonstrating that deep learning significantly improved the localization of cracks in MZ crowns. This development can potentially aid dentists in clinical decision-making by facilitating the early detection and prevention of crack failures.

The Efficacy of Ozonated Olive Oil in Crown Lengthening Procedures for Anterior Teeth: A Case Report.

Ensuring the health of the gums and supporting structures (periodontium) is crucial during dental restoration procedures to achieve optimal function and appearance of the teeth. Understanding the anatomy, the impact of restorative materials, and their interaction with the periodontium is essential for successful treatment outcomes. Crown lengthening is a surgical procedure that involves the removal of gingiva and bone tissue to expose more of the tooth structure, thereby increasing the visible portion of the tooth (clinical crown height). To protect the wound from mechanical trauma and stability of the surgical site during the healing process, periodontal dressing can be applied after surgery. Ozone therapy has demonstrated its effectiveness in promoting the healing of various types of wounds, including chronic and difficult-to-heal wounds, as an antibacterial agent and in modulating the immune system. Thus, this study aimed to compare, evaluate, and assess the use of periodontal dressing with that of ozonated olive oil after the crown lengthening procedure.

Dimensional changes of the gingival tissues induced by clear aligners and fixed orthodontic appliances: A retrospective study.

OBJECTIVE: The aim of this study was to evaluate gingival tissue adaption induced by orthodontic tooth movement, in terms of clinical crown height (i.e., attachment loss), and thickness of the keratinized gingiva at the margin level. METHODS: Pre- and post-treatment intraoral models/scans of 100 orthodontically treated patients (50 treated with clear aligners and 50 treated with fixed appliance) were acquired. Models were digitally scanned. Each couple of pre- and post-treatment scans were superimposed using the Compare© software (Medit spa, Seoul, Republic of Korea) taking the same reference landmarks in all cases, that were the palatal rugae for the upper arch, and the labial median frenulum for the lower arch. Only teeth that had undergone vestibulo-palatal (or vice versa) movement, greater than 1 mm were included in the analyses. The change from pre-treatment to post-treatment, in the clinical crown height and thickness of the keratinized gingiva at the margin level were digitally measured and compared between the two groups. Statistical analysis included paired t-tests, and unpaired t-tests with significance set at p<0.05. RESULTS: There was a statistically significant change in clinical crown height and gingival thickness in both groups. However, a clinically relevant attachment loss was found only within the fixed appliance group. Whereas, regarding the change in gingival thickness, there was no clinically relevant changes between the two groups. CONCLUSIONS: Orthodontic tooth movement with fixed appliance is associated to a clinically relevant attachment loss. Clear aligners seem to be associated with a more discrete attachment loss than the one observed with fixed appliances. CLINICAL RELEVANCE: Orthodontists should pay attention and monitoring the clinical crown height (i.e., attachment loss) during orthodontic movement, mostly when using fixed appliances.

Comparison of stress distribution around splinted and nonsplinted implants with different crown height space in posterior mandible: A finite element analysis study.

PURPOSE: The purpose of this finite element analysis (FEA) study was to analyze the stress distribution on prosthetic components of splinted and nonsplinted prostheses, bone, and implants with different crown height space (CHS). MATERIALS AND METHODS: Mandibular posterior segment was modeled with no resorption at the second premolar site and various amounts of resorption (0, 3, 6, and 9 mm) at the first molar site. Two adjacent implants (Straumann bone level implants, 4.1 mm×8 mm) were placed; at the second premolar site, the crown height was 8 mm and at the first molar site, the crown height varied (8, 11, 14, and 17 mm), depending on the amount of resorption. Both splinted and nonsplinted crowns were designed. Vertical and oblique loads of 400 N were applied to the crowns. von Mises stress was used to evaluate the stress distribution in the implant complex and maximum principal stress was used to evaluate the stress in the bone. RESULTS: When oblique forces were applied, the highest von Mises stresses were observed for nonsplinted crowns in the 17 mm CHS group. The maximum principal and minimum principal stresses observed in bone under oblique loading increased with increased CHS for nonsplinted restorations. CONCLUSIONS: Crown height affected the amount of stress in bone and implant components. When the crown height difference between two adjacent implants increases, splinting may be crucial.

Effect of Staining, Glazing and Polishing on the Survival Probability of Monolithic Zirconia Crowns.

OBJECTIVE: The purpose of this in vitro study was to evaluate the effect of staining, glazing, and polishing on the survival probability of monolithic crowns manufactured with preshaded stabilized zirconia with 5 mol% of yttrium oxide (5Y-TZP). MATERIALS AND METHODS: Monolithic crowns in the shape of an upper canine (1.5 mm of thickness) were manufactured by CAD/CAM, adhesively cemented on metallic foundation, and divided into 6 groups (n = 21): C (control), S (staining), G (glazing), P (polishing), SG (staining and glazing), and SP (staining and polishing). The survival probability was determined by step-stress accelerated life testing with a load applied to the palatine concavity of the crown. First, the specimens were subjected to a single-load to fracture test (SLF) and next to the fatigue test (5 Hz, thermocycling immersed in water varying 5-55°C), including the light (n = 9), moderate (n = 6), and aggressive (n = 3) loading profiles (load ranged between 20% and 60% of SLF). The survival probability was calculated considering the cycles for failure (CFF) and fatigue failure load (FFL) and illustrated using a Kaplan-Meier graph. The comparison among groups was performed using a Log-Rank test (α = 0.05). RESULTS: The mean value of SLF was 586.7 N. There was no difference among groups in survival probability, considering CFF and FFL. CONCLUSION: Staining, glazing, and polishing can be performed safely without damaging the mechanical behavior of 5Y-TZP monolithic crowns. CLINICAL SIGNIFICANCE: Staining is used to characterize and improve the esthetic of zirconia monolithic crowns. It can be used to reproduce the color gradient in the cervical region of the crown and pigmented grooves. This study showed that staining, glazing, and polishing did not affect the survival probability and the use of finishing procedures (glazing or polishing) after staining did not improve the survival probability of zirconia monolithic crowns.

Elinor Catherine Hamlin (1924-2020): 'The beloved daughter of Ethiopia'.

Elinor Catherine Hamlin (1924-2020) was a world-renowned Australian obstetrician and gynaecologist who dedicated almost her entire adult working life to eradicating obstetric fistula in Ethiopia. Leaving behind a comfortable life in Sydney and later Adelaide, she travelled with her husband Reginald Hamlin (1908-1993) to Addis Ababa in 1959, with the view to working there for three years and helping set up a midwifery school at the Princess Tsehai Memorial Hospital. But the couple ended up spending the rest of their lives in Ethiopia, where they revolutionised maternal healthcare services and standardised best practice measures for fistula patient care. In 1975 they jointly opened the Addis Ababa Fistula Hospital - at that time the only operating specialist fistula hospital in the world - which was destined to become a global centre of excellence in obstetric fistula surgery. Today the hospital carries on Catherine Hamlin's legacy as one of Sydney's most impactful medical graduates on the world stage.

Clinical performance of implant-assisted removable partial dentures using implant surveyed crowns: a systematic review and meta-analysis.

PURPOSE: This study aimed to evaluate the clinical performance of implant-assisted removable partial dentures (IARPD) with surveyed crowns, also known as implant-crown-retained removable partial dentures (ICRPDs). MATERIALS AND METHODS: Electronic searches of MEDLINE/PubMed, the Cochrane Central Register of Controlled Trials, the Web of Science, and the Korea Citation Index were performed according to the established search terms for ICRPD. A literature search was conducted for studies published in English or Korean until September 2023, using the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. RESULTS: A total of 216 journals were searched, and 31 eligible studies were selected based on the inclusion and exclusion criteria. One systematic review included five case reports of ICRPD. Nine retrospective studies evaluated implant survival/success rate, implant failure cases, marginal bone loss, periodontal status, clinical complications, and patient satisfaction. Twenty-one case reports published in Korea showed good prognoses. CONCLUSION: According to the findings of this systematic review, ICRPD has a reasonable survival/success rate, minimal bone loss, and high patient satisfaction.

Survival evaluation of surgical extrusion for the management of complicated crown-root fractured maxillary incisors: A clinical study.

This study aimed to clinically evaluate the survivability of surgically extruded teeth, to assess the success rate and predictable factors pertaining to alterations in both hard and soft tissues adjacent to extruded teeth. A total of 46 complicated crown-root fractured maxillary central and lateral incisors with >75% tooth structure loss relatively due to trauma were included. Preoperative clinical and radiographic variables were recorded. Single operator performed endodontic treatment before surgical extrusion. Patients were recalled for review at 6, 12, 18, 24 and 36 months. Survivability was assessed using Kaplan-Meier survival analysis. With a mean follow-up of 2.8 years, survival rate was 95.7%. Mobility observed in only two cases. The crown-root ratio was favourable (1:2) in all the cases except for five teeth. Only two teeth displayed non-progressive root resorption. Survival of surgically extruded teeth relies on significant predictors like favourability of CRR and implementation of atraumatic extrusion.

From Decay to Delight: A Case Report on Esthetic Rehabilitation in Early Childhood Caries.

Early childhood caries (ECC) continues to be a major global dental health concern for young children. This case report examines a young patient's transformation from decay to delight via comprehensive esthetic treatment. ECC in a four-year-old child resulted in significant dental caries and poor esthetics. In addition to space maintenance and orthodontic examination, essential treatments included dental extractions, stainless steel crowns, and composite restorations. The result showed that the child's smile and self-esteem had been successfully restored, as well as their oral health and function. This case emphasizes the value of early intervention, multidisciplinary teamwork, and individualized treatment plans in the management of early childhood caries and the restoration of pediatric patients' oral health.

Evaluating the Success of Preformed Resin Bonded Composite Strip Crowns for the Primary Central Incisor in Restoring Carious Primary Canine Teeth: A Retrospective Analysis.

Background Restoration of primary canine teeth in pediatric dentistry requires a balance of functional, biological, and esthetic factors. Stainless steel crowns, while effective for posterior restorations, often have patient acceptance issues due to esthetic limitations. Resin-bonded composite strip crowns have gained traction for anterior restorations due to their superior esthetic qualities and repairability. However, their long-term performance in primary canines characterized by unique morphological and functional demands has not been thoroughly evaluated. This study investigates the efficacy of resin-bonded incisor strip crowns in primary canines over three years, assessing their functional durability, biological integrity, and esthetic performance to provide a comprehensive evaluation of their long-term success in this application. Methods This retrospective observational study, conducted from September 2023 to December 2023 at the Department of Pediatric and Preventive Dentistry, Saveetha Dental College and Hospitals, Chennai, Tamil Nadu, India, received ethical approval from the Institutional Human Ethical Committee (IHEC/SDC/PEDO-2103/23/131). Dental records from January 2020 to December 2020 were reviewed by two investigators to identify children aged six years or younger who had undergone pulpectomy in primary canine teeth and were restored with resin-bonded incisor strip crowns. Exclusions included records with missing contact details or post-treatment radiographs. The purpose was to ensure a three-year review period when contacting patients in 2023. Eligible parents were contacted by phone, informed about the study, and invited for a review. Informed consent was obtained in person. Children with exfoliated primary canines and those whose parents did not sign the consent form were excluded. The restored crowns were evaluated using World Dental Federation (FDI) criteria across functional, biological, and esthetic domains by two calibrated examiners. Statistical analysis was conducted using IBM SPSS Statistics for Windows, Version 24 (Released 2016; IBM Corp., Armonk, New York, United States), with categorical variables expressed as n (%), inter-examiner reliability assessed by Cohen's kappa, and chi-square test used for goodness of fit, setting significance at 95%. Results Of the 92 primary canines restored with resin-bonded incisor strip crowns, 60 children were evaluated. The retention rate at the three-year follow-up was 50 (83.3%). Functional evaluation revealed that 48 (80%) of crowns maintained surface texture, 42 (70%) preserved form and contour, and 52 (86.6%) demonstrated acceptable occlusion and wear. Biologically, 55 (91.7%) of the crowns had no secondary caries, and 56 (93.4%) had no dental hard tissue defects at the margin. Esthetically, 48 (80%) of crowns retained surface texture, 46 (76.6%) had a satisfactory color match, and 45 (71.6%) exhibited minimal marginal staining. Statistical analysis confirmed significant results for all functional and esthetic parameters (p < 0.05). Conclusion The technique of placing incisor strip crowns in the place of primary canines can be recommended considering its maintenance of functional, biological, and esthetic properties.

Comparison of Mineral Density of Dental Structures of Ancient Human Skeletons from the Roman Period with Modern-Day Human Dental Structures.

OBJECTIVES: Comparison of maxillary, mandibular, dental crown and root mineral density in human skeletons identified in historical excavations with today's human maxillary, mandibular dental crown and root. METHODS: After the skull images were obtained, four groups were created: maxilla 1, mandible 1 from the old period, maxilla 2 from the images taken from today's patients, and mandible 2 from the images taken from today's patients. Seventeen skeletons were previously classified as young age, middle age, and older age. Among the archive tomography images, 17 images from young (15-35), middle (36-56) and older (57 and over) age images were included in the study. HU value of the desired region was calculated automatically by the device using Region of interest (ROI). RESULTS: In this study, 34 jaws and 68 teeth were evaluated, including 7 mandibles and 10 maxillae from the late Roman period, and 8 mandibles and 9 maxillae from today's people. The average HU value of the crowns of mandibular anterior teeth from the late Roman period was measured as 2406.0. The average HU value of the crowns of maxillary anterior teeth was found to be 3383.8. In the posterior aspect, the average crown HU value measured in the maxilla was found to be higher than that in the mandible. CONCLUSIONS: The finding showed that the density of dental tissues of ancient people, such as enamel and dentin forming the crown, and cementum and dentin forming the root, was significantly higher than today's people.

Digital social responsibility towards digital education of international higher education students' institutions: Digital culture as mediator.

Digital social responsibility (DSR) has emerged as a wise strategic decision for all higher education institutions during the new crown pandemic. This study explores whether the DSR dimensions (social, economic, legal, and environmental) enhance digital education (DE) in universities. Specifically, this paper intends to investigate the impact of digital culture (DC) on these relationships as a mediator variable. By adopting a cross-sectional approach, data are gathered through an online survey among a sample of 181 students from different nationalities in higher education institutions in Chang'an-China. The partial least squares-structural equation modelling has been used to perform the statistical analyses. Results revealed that all DSR dimensions directly and indirectly affect DE. DC also significantly influences students' DE during the new crown pandemic. Furthermore, our findings show that DC mediates the link between the social, economic, and environmental DSR aspects and students' DE. The study suggests Chinese universities review their DSR policies and student DC perspectives, and design social digital responsibility education programs. These measures can predict the success of student DE and provide a competitive edge as social media technology advances.