Accuracy and clinical fit of milled versus rapid prototyped orthognathic surgical splints.

Three-dimensional (3D) printing has slowly become an integral part of orthognathic surgery. However, there is a lack of studies evaluating accuracy of orthognathic surgical splints fabricated from subtractive milling versus additive 3D printing. The primary aim of this in vitro study was to compare the differences in trueness between milled and 3D-printed splints, while the secondary aim was to compare the differences in clinical fit of these splints. A sample of eight patients was selected, and STL files of the final orthognathic surgical splint were used to fabricate three splints for each of the eight cases. The first splint was fabricated by subtractive milling (SM), whereas the second and third splints were 3D printed with Digital Light Processing (DLP) and Laser Stereolithography (SLA), respectively. Paired superimposition of scans was performed using a reference model. The clinical fit of the splints to the printed models was also assessed. The mean root mean square (RMS) deviations for the SM, SLA, and DLP were 0.11 ± 0.02, 0.16 ± 0.02 and 0.14 ± 0.02 respectively. The post-hoc analysis showed that the SM splints had the highest accuracy (p<0.01). However, DLP splints showed the best clinical fit, followed by SM and SLA. In conclusion, splints fabricated by SM were more accurate than those fabricated by 3D printing, although this difference may not be clinically significant. The site, rather than the magnitude of the errors, may have a greater effect on the clinical usability of splints. In general, SM and DLP splints demonstrated a good clinical fit and were suitable for the fabrication of surgical splints.

Internal fit and marginal adaptation of all-ceramic implant-supported hybrid abutment crowns with custom-milled screw-channels on Titanium-base: in-vitro study.

BACKGROUND: Advancements in digital dentistry helped in custom-milling screw-channels in implant-supported restorations; however, the fit of these restorations is still unclear especially for contemporary computer aided designing/computer aided manufacturing (CAD/CAM) materials. This study aimed to compare the internal and marginal fit of Ultra translucent multilayered zirconia versus lithium disilicate implant-supported hybrid abutment crowns (HACs) constructed with custom-milled screw-channels on Titanium-base. MATERIALS AND METHODS: A total of 24 HACs with custom-milled screw-channels were constructed from lithium disilicate (Group LDS) and Ultra translucent multilayered zirconia (Group UT) using digital workflow (n = 12). The internal and marginal gaps of HACs on their corresponding Titanium-bases were assessed using replica technique and stereomicroscope, respectively. After testing for normality, quantitative data were expressed as mean and standard deviation and compared using independent t-test at a level of significance (P ≤ 0.05). RESULTS: There was no statistically significant difference between Group LDS and Group UT in terms of marginal and internal fit. The internal and marginal gaps in both groups were within the accepted values reported in literature. CONCLUSIONS: UT and LDS HACs with custom-milled screw-channels demonstrated comparable and acceptable internal fit and marginal adaptations to Ti-base, which lied within the range reported in literature.

The effect of two preparation designs on the fracture resistance and marginal adaptation of two types of ceramic crowns using CAD/CAM technology (In vitro study).

BACKGROUND: Recently, prosthodontic approaches involve more conservative procedures that include less invasive finish line preparations that use less ceramic thickness. AIM OF THE STUDY: This in vitro study aimed to evaluate the effect of vertical preparation and modified vertical preparation designs on the marginal adaptation and fracture resistance of two types of ceramic crowns using CAD/CAM technology. MATERIALS AND METHODS: Two typodont maxillary first premolars were embedded in acrylic resin. Forty positive replicas of epoxy resin dies were used that were divided into two groups depending on the preparation design (n = 20); Group V (Vertical): dies with feather edge finish line and Group MV (Modified vertical): dies with feather edge finish line, where a reverse shoulder of 1 mm depth was placed on the buccal surface 1.5 mm from the occlusal surface. Each group was further subdivided into two subgroups according to the type of ceramic material (n = 10): Subgroup Va and subgroup MVa for lithium disilicate (e.max CAD) and subgroup Vb and subgroup MVb for zirconia (zolid ht+). Crown restorations were made with CAD-CAM technology. The marginal adaptation was assessed using a stereomicroscope both prior to cementation and after cementation and aging. Fracture resistance was tested with a universal testing machine, and the data were statistically analyzed. RESULTS: Marginal adaptation showed no significant differences between subgroups before or after cementation and aging. Three-way ANOVA indicated that preparation design (p = 0.516) and material (p = 0.269) had no significant effect, but cementation had a significant effect (p < 0.0001) on the marginal adaptation. According to two-way ANOVA test, Subgroup (MVb) showed the highest result followed by subgroup (Vb) and subgroub (MVa) and the least was subgroub (Va). Fracture modes showed no significant differences among the subgroups (p = 0.982). CONCLUSIONS: Marginal adaptation of lithium disilicate and zirconia crowns remained clinically acceptable regardless of preparation design. While the modified vertical preparation with a reverse shoulder notably enhanced the fracture resistance of both materials, with zirconia demonstrating superior fracture resistance compared to lithium disilicate with average values exceeding premolar biting force.

Impact of body mass index on repeat coronary revascularization rates in patients with LDL-C below 55 mg/dL and LDL-C below 70 mg/dL: a 42-month cohort study in Korea.

Background: Previous studies revealed a linear relationship between body mass index (BMI) and repeat coronary revascularization rate in patients who underwent percutaneous coronary intervention (PCI). However, this relationship has not been demonstrated in Korean patients who meet old and new target low-density lipoprotein cholesterol (LDL-C) levels of Korean dyslipidemia guidelines. Therefore, we conducted this study to find out the effect of BMI on repeat coronary revascularization rate in patients with LDL-C <55 mg/dL and patients with LDL-C <70 mg/dL. Methods: This cohort study was followed for 42 months in Daegu Catholic Medical Center, Korea. We included 429 patients with LDL-C <70 mg/dL 1 year after PCI. We compared repeat revascularization rates using Kaplan-Meier survival curves between the normal weight group (18.5 kg/m2 ≤ BMI < 23 kg/m2) and the pre-obesity and obesity group (23 kg/m2 ≤ BMI) in patients with LDL-C <55 mg/dL and patients with LDL-C <70 mg/dL. Results: During a follow-up period, there was no significant difference in repeat coronary revascularization-free survival between a group with LDL-C <55 mg/dL and a group with LDL-C <70 mg/dL (79.6% vs. 76.2%, P=0.32). In normal weight patients, LDL-C <55 mg/dL group showed higher repeat coronary revascularization-free survival than LDL-C <70 mg/dL group (89.3% vs. 77.1%, P=0.05). There was no significant difference in repeat revascularization-free survival between the normal weight group and the pre-obesity and obesity group in patients with LDL-C <70 mg/dL (77.1% vs. 75.7%, P=0.67). However, the normal weight group showed significantly higher repeat revascularization-free survival compared to the pre-obesity and obesity group in patients with LDL-C <55 mg/dL (89.3% vs. 74.3%, P=0.03). Normal body weight and LDL-C <55 mg/dL [hazard ratio (HR): 0.421, 95% confidence interval (CI): 0.193-0.916, P=0.02] was the only independent predictor for repeat revascularization. Conclusions: In Korean PCI patients with normal body weight whose LDL-C level is less than 70 mg/dL, but more than 55 mg/dL, should be treated with more intensive therapy to lower LDL-C to less than 55 mg/dL. For obese patients who have succeeded in reducing LDL-C below 55 mg/dL, it seems that weight loss should be attempted to a normal body weight level.

Fracture strength of cad-cam milled polyetheretherketone (PEEK) post-cores vs conventional post-cores; an in vitro study.

Background: The aim of this study was to compare the fracture strength and fracture modes of post-cores produced with CAD-CAM from modified polyetheretherketone (PEEK) materials with other custom-produced post-cores. Methods: Sixty human mandibular first premolars with equal root sizes were used. The teeth were divided into six groups (n = 10), and root canal treatment was performed. The teeth were separated from the roots over 2 mm from the cemento-enamel junction. As a result of the decoronation process, a 1 mm wide shoulder line was obtained for all teeth. For the fracture strength test, 10 mm deep post spaces were created on the teeth with a 1.6 mm diameter driller. Post-core groups consisted: everStick® glass fiber post-core (Group GF), zirconia post-core (Group Z), metal (Cr-Co) post-core (Group M), PEEK post-core without filler (Group UP), PEEK post-core with 20% TiO2 Filler (Group TP), and post-core with 20% ceramic filler (Group CP). Following the application of posts to post spaces, copings were created and cemented on the samples. With the universal tester, a force was applied to the long axis of the tooth with a slope of 135°. The mean fracture strength (N) between the groups was statistically evaluated using one-way ANOVA, and pairwise mean differences were detected using post hoc Tukey's HSD test among the groups. Results: According to the results of the statistical analysis, a significant difference was found between the groups in terms of mean fracture resistance (p < 0.05). Group Z (409.34 ± 45.72) was significantly higher than Group UP (286.64 ± 37.79), CP (298.00 ± 72.30), and TP (280.08 ± 67.83). Group M (376.17 ± 73.28) was significantly higher than Group UP (286.64 ± 37.79) and Group TP (280.08 ± 67.83). There were no statistically significant differences between the means of the other groups (p > 0.05). Among all the groups, Group Z exhibited a higher prevalence of repairable failure modes, while the rest of the groups predominantly experienced irreparable failure modes. Conclusion: In our study, zirconia and metal post-core samples showed higher average fracture strength values than PEEK post-cores groups. Repairable failure modes were more common in the zirconia post-cores, whereas the opposite was observed in the other groups. Further experimental and clinical trial studies are needed before PEEK materials can be used as post materials in the clinic.

Prevalence and risk factors associated with coronary artery disease in Iranian patients with peripheral artery disease.

INTRODUCTION: It is well known that peripheral artery disease (PAD) and coronary artery disease (CAD) coexist and therefore, patients diagnosed with PAD have an increased chance of developing concomitant CAD. CAD-related complications could be a leading cause of postoperative mortality in individuals with PAD undergoing vascular surgery. We present a case series of 48 patients who underwent coronary angiography before vascular surgery and an updated review of previous reports to determine the prevalence of concomitant CAD in a convenience sample of Iranian patients. METHODS: This cross-sectional study was performed on 48 patients with confirmed PAD admitted to Imam Ali Hospital, affiliated with the Kermanshah University of Medical Sciences (KUMS), Kermanshah Province, Iran. A vascular surgeon diagnosed PAD based on the patient's symptoms, Doppler ultrasound, and CT angiography (CTA). All patients underwent coronary angiography to determine if they also had CAD. We defined significant CAD as a ≥70% luminal diameter narrowing of a major epicardial artery or a ≥50% narrowing of the left main coronary artery. RESULTS: Of 48 patients, 35 (72.9%) were male, 13 (27.1%) were female, and the mean age was 64.18±12.11 years (range, 30 to 100 years). The incidence of CAD in patients with PVD was 85.42% (41/48). The patients with CAD were more likely to be hypertensive than those without CAD (80.5 vs. 14.3, p-value<0.001). Of 41 patients with CAD, 9 (22.0%) had one-vessel disease, 10 (24.3%) had two-vessel disease, and 22 (53.7%) had three-vessel disease. CONCLUSION: Hypertension was a significant risk factor for CAD. Patients with hypertension and multiple major coronary risk factors scheduled for PVD surgery should be carefully evaluated for concomitant CAD.

The message matters: changes to binary Computer Aided Detection recommendations affect cancer detection in low prevalence search.

Computer Aided Detection (CAD) has been used to help readers find cancers in mammograms. Although these automated systems have been shown to help cancer detection when accurate, the presence of CAD also leads to an over-reliance effect where miss errors and false alarms increase when the CAD system fails. Previous research investigated CAD systems which overlayed salient exogenous cues onto the image to highlight suspicious areas. These salient cues capture attention which may exacerbate the over-reliance effect. Furthermore, overlaying CAD cues directly on the mammogram occludes sections of breast tissue which may disrupt global statistics useful for cancer detection. In this study we investigated whether an over-reliance effect occurred with a binary CAD system, which instead of overlaying a CAD cue onto the mammogram, reported a message alongside the mammogram indicating the possible presence of a cancer. We manipulated the certainty of the message and whether it was presented only to indicate the presence of a cancer, or whether a message was displayed on every mammogram to state whether a cancer was present or absent. The results showed that although an over-reliance effect still occurred with binary CAD systems miss errors were reduced when the CAD message was more definitive and only presented to alert readers of a possible cancer.

Evaluating the accuracy of CEREC intraoral scanners for inlay restorations: impact of adjacent tooth materials.

BACKGROUND: The accuracy of intraoral scanning is critical for computer-aided design/computer-aided manufacturing workflows in dentistry. However, data regarding the scanning accuracy of various adjacent restorative materials and intraoral scanners are lacking. This in vitro study aimed to evaluate the effect of adjacent restorative material type and CEREC's intraoral scanners on the accuracy of intraoral digital impressions for inlay cavities. METHODS: The artificial tooth was prepared with an occlusal cavity depth of 2 mm, a proximal box width at the gingival floor of 1.5 mm, and an equi-gingival margin extended disto-occlusally at the transition line angle on both the lingual and buccal sides for an inlay restoration. The adjacent teeth were veneered with crowns made of gold and zirconia, and an artificial tooth (resin) was utilized as the control group. The inlay cavity and adjacent teeth (Gold, Zirconia, and resin) were scanned 10 times using Chairside Economical Restoration of Esthetic Ceramics (CEREC) Primescan (PS), Omnicam (OC), and Bluecam (BC). A reference scan was obtained using a laboratory scanner (3-shape E3). Scanning was performed according to the manufacturer's instructions, including powder application for the BC group. Standard tesselation language files were analyzed using a three-dimensional analysis software program. Experimental data were analyzed using a two-way analysis of variance and the Tukey's post-hoc comparison test. RESULTS: The restorative materials of the adjacent teeth significantly affected the accuracy of the intraoral digital impressions (p < .05). The zirconia group exhibited the highest trueness deviation, followed by the resin and gold groups, with each demonstrating a statistically significant difference (p < .05). The resin group demonstrated the highest maximum positive deviation and deviation in precision. Gold exhibited the lowest average deviation value for trueness compared with those of the other adjacent restorative materials. Intraoral scanner type significantly influenced the trueness and precision of the scan data (p < .05). The average deviation of trueness according to the intraoral scanner type increased in the following order: BC > PS > OC. The average deviation in precision increased in the following order: PS>OC>BC (p < .05). CONCLUSION: The restorative materials of the adjacent tooth and the type of intraoral scanner affect the accuracy of the intraoral digital impression. The trueness of the digital images of the BC group, obtained by spraying the powder, was comparable to that of the PS group. Among the adjacent restorative materials, zirconia exhibited the lowest trueness. In contrast, PS demonstrated the highest precision among the intraoral scanners, while resin displayed the lowest precision among the adjacent restorative materials.

Advantages of using Genetically Elevated Lipoprotein(a) Levels in Predicting 5-Year Major Adverse Cardiovascular Events Relating to Coronary Artery Disease in Women.

Background: This study aimed to investigate major adverse cardiovascular events (MACE) in patients with coronary artery disease (CAD) over 5 years, in general, and depending on sex, lipoprotein(a) level, and number of kringle IV type 2 (KIV-2) repeats in the Lipoprotein(A) (LPA) gene. Methods: This study comprised 216 patients (120 women and 96 men) hospitalized with a diagnosis of "CAD, unstable angina IIB class". The three-point risk of MACEs was assessed over 5 years: cardiovascular death, non-fatal myocardial infarction, and stroke. The number of KIV-2 repeats in the LPA gene was determined by quantitative real-time polymerase chain reaction (qPCR). Results: The relative risk of MACE in patients with elevated lipoprotein(a) (Lp(a)) was 2.0 (95% CI 1.04-3.87, p < 0.05) for quartile 4 (Q4) ≥ 48 mg/dL versus quartile 1 (Q1) ≤ 6 mg/dL. This was mainly attributable to an increase in men-relative risk (RR) 2.6 (95% CI 1.10-6.16, p < 0.05)-but not in women: RR 1.4 (95% CI 0.50-3.92). Mean lipoprotein(a) levels were inversely correlated with 42.5 and 7.5 for Q1 and Q4 KIV-2 repeat numbers, respectively. The relative risks of MACE for Q1 vs. Q4 KIV-2 repeats were as follows: 3.0 (95% CI 1.48-6.08, p < 0.001) for all patients; 3.0 (95% CI 1.20-6.55, p < 0.01) for men; 3.3 (95% CI 1.02-10.4, p < 0.05) for women. Conclusions: Quantifying kringle IV type 2 repeat copy number in the LPA gene using qPCR more accurately reflects the risk of major adverse cardiovascular events within 5 years in women with coronary artery disease.

Cranioplasty using patient specific implants Polyether ether ketone versus ultra-high molecular weight polyethylene: A prospective study.

This prospective study aimed to compare ultra-high molecular weight polyethylene (UHMWPE) with polyetheretherketone (PEEK) in computer-designed patient-specific implants (PSIs) for cranial defect reconstruction, in terms of complications and aesthetic outcomes. Primary or secondary cranioplasty-eligible patients were included, while patients with active infection or hydrocephalus, or unfit for general anesthesia, were excluded from the study. All the implants were designed and fabricated by the same maxillofacial surgeon using CAD/CAM technology. UHMWPE PSIs were used in group 1 and PEEK PSIs in group 2. Technically, UHMWPE could be milled to a thinner margin thickness than PEEK, which resulted in better handling properties and a smoother end finish. All patients were evaluated over a period of 6 months in terms of overall complications or implant failure as the primary outcome, according to Clavien-Dindo (CVD) grading, and cosmetic satisfaction with the aesthetic results, using a Likert scale, as the secondary outcome. In total, 22 cranioplasty patients were included, with a mean age of 30.8 years (SD = 16.3). Across both groups, 17 patients (77.3%) did not develop postoperative complications. These occurred in three patients in group 1 (CVD grade I, II, and IIIb) (27.3%) and in two patients in group 2 (CVD grade II, IIIa, and IIIb) (18.2%), with no statistical difference (p = 0.6). None of the cases in both groups developed any clinical or radiographic signs of infection, or suffered implant failure. The mean satisfaction score was 4.8 in group 1 and 4.5 in group 2 (SD = 0.6). The difference in satisfaction scores between the two was not statistically significant (p = 0.23). Although UHMWPEE was comparable to PEEK in terms of overall complication rates and cosmesis after craniectomy, UHMWPEE as a material exhibited greater resiliency in technically challenging cases with large, complex/midline-crossing designs, previously fitted meshes, or single-stage resection-reconstruction, allowing better marginal adaptation.

A multicentre study to evaluate the diagnostic performance of a novel CAD software, DecXpert, for radiological diagnosis of tuberculosis in the northern Indian population.

Tuberculosis (TB) is the leading cause of mortality among infectious diseases globally. Effectively managing TB requires early identification of individuals with TB disease. Resource-constrained settings often lack skilled professionals for interpreting chest X-rays (CXRs) used in TB diagnosis. To address this challenge, we developed "DecXpert" a novel Computer-Aided Detection (CAD) software solution based on deep neural networks for early TB diagnosis from CXRs, aiming to detect subtle abnormalities that may be overlooked by human interpretation alone. This study was conducted on the largest cohort size to date, where the performance of a CAD software (DecXpert version 1.4) was validated against the gold standard molecular diagnostic technique, GeneXpert MTB/RIF, analyzing data from 4363 individuals across 12 primary health care centers and one tertiary hospital in North India. DecXpert demonstrated 88% sensitivity (95% CI 0.85-0.93) and 85% specificity (95% CI 0.82-0.91) for active TB detection. Incorporating demographics, DecXpert achieved an area under the curve of 0.91 (95% CI 0.88-0.94), indicating robust diagnostic performance. Our findings establish DecXpert's potential as an accurate, efficient AI solution for early identification of active TB cases. Deployed as a screening tool in resource-limited settings, DecXpert could enable early identification of individuals with TB disease and facilitate effective TB management where skilled radiological interpretation is limited.

3D printed versus milled stabilization splints for the management of bruxism and temporomandibular disorders: study protocol for a randomized prospective single-blinded crossover trial.

BACKGROUND: Nowadays, stabilization splints for the management of bruxism and temporomandibular disorders (TMD) can be produced utilizing a digital workflow comprising a digital impression of the teeth, digital splint design, and computer-aided manufacturing of the splints. The latter is usually a milling process, however, more recently 3D printing gained popularity due to its better cost and time efficiency. It remains unknown whether 3D printed stabilization splints are inferior to milled splints regarding clinical outcomes. METHODS: This clinical trial assesses the non-inferiority of 3D printed occlusal splints compared to milled occlusal splints in a monocentric prospective randomized single-blinded crossover trial with two cohorts. One cohort includes 20 participants with bruxism, the other 20 participants with pain-related TMD, i.e., myalgia, myofascial pain, or arthralgia of the jaw muscles/the temporomandibular joint(s) diagnosed according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Michigan-type stabilization splints are fabricated in a digital workflow by milling or 3D printing using CE-marked materials within their intended purpose. The participants wear a milled and a 3D printed splint in a randomized order for 3 months each, with follow-up visits after 2 weeks and 3 months. Investigated outcome parameters are oral health-related quality of life (OHRQoL) evaluated by the Oral Health Impact Profile (OHIP-G14), participant satisfaction as rated on a visual analog scale, therapeutic efficacy, and technical result of the splints. In this context, therapeutic efficacy means antagonist wear and-in the TMD group-reduction of pain/disability assessed by the Graded Chronic Pain Scale (GCPS v2.0) and clinical assessment following the DC/TMD standard, while technical outcome measures splint fit, wear and fracture rate. DISCUSSION: The trial will provide important information on the clinical outcome of 3D printed stabilization splints in comparison to milled splints and will, therefore, enable an evidence-based decision in favor of or against a manufacturing process. This, in turn, will guarantee for a maximum of the patient's OHRQoL during splint therapy, therapeutic efficacy, and longevity of the splints. TRIAL REGISTRATION: German Clinical Trials Register (DRKS) DRKS00033904. Registered on March 15, 2024.

A Deep Learning Based Intelligent Decision Support System for Automatic Detection of Brain Tumor.

Brain tumor (BT) is an awful disease and one of the foremost causes of death in human beings. BT develops mainly in 2 stages and varies by volume, form, and structure, and can be cured with special clinical procedures such as chemotherapy, radiotherapy, and surgical mediation. With revolutionary advancements in radiomics and research in medical imaging in the past few years, computer-aided diagnostic systems (CAD), especially deep learning, have played a key role in the automatic detection and diagnosing of various diseases and significantly provided accurate decision support systems for medical clinicians. Thus, convolution neural network (CNN) is a commonly utilized methodology developed for detecting various diseases from medical images because it is capable of extracting distinct features from an image under investigation. In this study, a deep learning approach is utilized to extricate distinct features from brain images in order to detect BT. Hence, CNN from scratch and transfer learning models (VGG-16, VGG-19, and LeNet-5) are developed and tested on brain images to build an intelligent decision support system for detecting BT. Since deep learning models require large volumes of data, data augmentation is used to populate the existing dataset synthetically in order to utilize the best fit detecting models. Hyperparameter tuning was conducted to set the optimum parameters for training the models. The achieved results show that VGG models outperformed others with an accuracy rate of 99.24%, average precision of 99%, average recall of 99%, average specificity of 99%, and average f1-score of 99% each. The results of the proposed models compared to the other state-of-the-art models in the literature show better performance of the proposed models in terms of accuracy, sensitivity, specificity, and f1-score. Moreover, comparative analysis shows that the proposed models are reliable in that they can be used for detecting BT as well as helping medical practitioners to diagnose BT.

Modified Surgical Guide for Root Sectioning in the Socket Shield Technique-In Vitro Study.

OBJECTIVE: This in vitro study aimed to evaluate the effectiveness of a printed surgical guide for root sectioning in the socket-shield technique. MATERIALS AND METHODS: A typodont model of the maxilla with augmented filler was used for the upper right central incisor, and CBCT images were obtained. Two types of vertical root sectioning guides were tested: one with a buccal sleeve (Group A, n = 10) and another with a buccal orientation slit (Group B, n = 10). Control group (n = 10) performed freehand cuts on printed models. After crown cutting with diamond burs, root sectioning was conducted using an ultrasonic tip with the guides. Mean and standard deviation were calculated for the remaining root length, width, and volume. Data were analyzed using the Kruskal-Wallis test and Dunn's post hoc test. RESULTS: Statistical analysis showed significant differences in root width between the control group (2.0 mm) and both Groups A (2.655 mm; p < 0.0001) and B (2.460 mm; p < 0.0001). Group B (5.585 mm) also showed a significant difference in root remnant compared with the control (13.880 mm; p < 0.0043). Groups A and B did not differ significantly from each other. CONCLUSIONS: The socket shield technique is safe and effective, this study aimed to add improvements through the introduction of surgical guides, facilitating the root section, which is the critical phase so that the parameters that are requisite for success are achieved in terms of width, length, and volume of the root remnant. Both guided techniques effectively facilitated root sectioning, maintaining satisfactory root thickness and length. CLINICAL SIGNIFICANCE: Sectioning the root is challenging for the correct angulation to remove the palatal portion in the socket shield technique. Therefore, modifying this technique with the use of the presented guides, it is possible to prevent damage to the soft tissues and to plan the surgery with the help of cone beam computed tomography (CBCT) scans to remove the root apex and maintain the root remnant with a thickness greater than 1.5 mm, making the socket-shield technique more predictable.

Study concerning the design and functionality of individual emergency shelters.

The divide between the rich and poor in the European housing market is fast rising. Latest research indicates that Europe is dealing with an increasing number of homeless people. Every city in Europe has them-homeless people compelled to live on street corners, frequently hiding themselves with cardboard. Rain, snow, and temperatures below zero pose a threat to their lives on a daily basis. There are many varied kinds of services that have been discovered, but it is difficult to keep track of everyone and guarantee that they have a warm night's sleep in the winter. The current article suggests accommodation as a workaround until they can receive high-intensity support, a way to keep a single person warm and safe during the winter. The focus is on devising a strategy that not only ensures the warmth and safety of individuals during the harsh winter months but also seeks to industrialize the construction of shelters, ensuring affordability below the cost of winter hospitalization for a homeless person. Crucially, the article introduces an additional layer to this initiative by highlighting the dual purpose of these individual shelters. Beyond being a means to provide respite for the homeless during severe weather, these shelters are envisioned as immediate response units in the event of emergencies such as earthquakes in urban areas. The article explores the potential impact of this multi-layered approach on transforming urban landscapes and fostering resilient communities.

The predictive value of coronary artery calcium score combined with traditional risk factors for obstructive coronary heart disease in young people.

OBJECTIVES: This study attempts to compare the predictive effects of several prediction models on obstructive coronary artery disease (OCAD) in young patients (30-50 years old), with a view to providing a new evaluation tool for the prediction of premature coronary artery disease (PCAD). METHODS: A total of 532 hospitalized patients aged 30-50 were included in the study.All of them underwent coronary computed tomography angiography (CCTA) for suspected symptoms of coronary heart disease.Coronary artery calcium score (CACS) combined with traditional risk factors and pre-test probability models are the prediction models to be compared in this study.The PTP model was selected from the upgraded Diamond-Forrester model (UDFM) and the Duke clinical score (DCS). RESULTS: All patients included in the study were aged 30-50 years. Among them, women accounted for 24.4%, and 355 patients (66.7%) had a CACS of 0. OCAD was diagnosed in 43 patients (8.1%). The CACS combined with traditional risk factors to predict the OCAD area under the curve of receiver operating characteristic (ROC) (AUC = 0.794,p < 0.001) was greater than the PTP models (AUCUDFM=0.6977,p < 0.001;AUCDCS=0.6214,p < 0.001). By calculating the net reclassification index (NRI) and the integrated discrimination index (IDI), the ability to predict the risk of OCAD using the CACS combined with traditional risk factors was improved compared with the PTP models (NRI&IDI > 0,p < 0.05). CONCLUSION: The predictive value of CACS combined with traditional risk factors for OCAD in young patients is better than the PTP models.

Changes in the surface texture of pre-polymerized acrylic resin pediatric crowns following acidulated phosphate fluoride application.

This study aimed to investigate the effect of acidulated phosphate fluoride (APF) application on filler-free polymethyl methacrylate (PMMA)-based resin blocks for computer-aided design/computer-aided manufacturing (CAD-CAM), focusing on their use in pediatric crowns. Three types of PMMA-based blocks for CAD-CAM were evaluated, and a composite resin block for CAD-CAM was used as a control. Statistical analysis (p<0.05) of the data revealed that all PMMA-based blocks showed significantly higher gloss levels than the composite resin blocks. Two PMMA-based blocks also demonstrated significantly lower Ra and Sa values. SEM images showed no irregular changes in the surface properties of the PMMA-based blocks compared to those of the composite resin block. These results are significant in meeting the increasing demand for esthetic restorative treatments in pediatrics, where APF is commonly used for caries prevention. PMMA-based resin blocks for CAD-CAM are an effective alternative to prevent esthetic degradation from gloss reduction and plaque accumulation.

Microstructural and flexural strength of various CAD-CAM lithium disilicate ceramics.

PURPOSE: To analyze the microstructural and mechanical properties of various commercial trademarks of lithium disilicate ceramics for CAD-CAM systems. MATERIALS AND METHODS: Specimens of different lithium disilicate ceramics were obtained and randomized into 5 groups (n = 14): EM: e.max CAD; RT: Rosetta SM; EV: Evolith; PM: Smile-Lithium CAD; and, HS: HaHaSmile. The microstructural analysis was performed by X-ray diffraction (XRD) and scanning electron microscopy (SEM); for flexural strength, the three-point bending flexure test was used. XRD and SEM data were qualitatively evaluated. Data from flexural strength were assessed with one-way ANOVA test (α = 0.05) and Weibull analysis. RESULTS: High peaks corresponding to the lithium metasilicate and lithium disilicate pattern with similar intensities were observed in all ceramics in the XRD analysis. SEM images showed similar patterns of crystalline structure in the EM and RT ceramics, while the other three groups presented different crystal morphologies than the previous ones and were similar to each other. No differences were found in flexural strength among the groups (p = 0.28). CONCLUSIONS: The CAD-CAM lithium disilicate ceramics showed comparable crystalline intensities. The microstructure of the EM and RT ceramics were different from the other groups. Flexural strength was similar among all ceramics.

Influence of CAD-CAM manufacturing methods on the accuracy and mechanical properties of implant-supported prostheses: A systematic review.

PURPOSE: This systematic review aimed to provide comprehensive insights on the accuracy, fit, and mechanical characteristics of implant-supported computer-aided design and computer-aided manufacturing (CAD-CAM) prostheses, with a focus on milled and 3D-printed approaches. METHODS: The research question focused on implant-supported dental prostheses, comparing different manufacturing techniques (conventional, milled, and 3D-printed) to determine the different factors affecting the mechanical properties and fit of the CAD-CAM implant-supported prosthesis. The eligibility criteria encompassed studies involving implant-supported restorations, clear reporting of manufacturing techniques, and English-language publications from the last decade. The search was conducted across three main databases, MEDLINE, Scopus, and Web of Science in September 2023. Publication details, study characteristics, and methodological details of each included study were described. RESULTS: Of the initial 1964 articles, 581 met the inclusion criteria, and 104 studies were included in the final qualitative analysis. The majority of studies were conducted in the United States, Turkey, and Brazil. Fourteen studies evaluated accuracy parameters, while four studies focused on mechanical characteristics. The studies revealed variability in mechanical properties and marginal and internal fit, with fabrication methods impacting the structural integrity and stress distribution of the prostheses. CONCLUSIONS: The findings suggest that digital manufacturing workflows, both milling and 3D printing, yield acceptable properties for implant-supported restorations with minimal variations in fit and accuracy. Notably, 3D printing and hybrid techniques demonstrate advantages in specific aspects like marginal fit and stress distribution. However, the milled prosthesis provided superior results in flexural strength and fracture resistance compared to conventional methods. Further research is needed to confirm these findings in clinical settings.

Effect of cut-out rescanning protocol on the accuracy of digital impressions in convergent implants positioned at varying depths: An in vitro study.

BACKGROUND: This study aimed to assess the effect of the "cut-out rescan" strategy on the accuracy of intraoral digital scans from 25° convergent implants positioned at two distinct depths. MATERIAL AND METHODS: Two customized models were fabricated, each designated to receive two posterior converged implant fixtures: one at a depth of 1 mm and the other at a depth of 4 mm. Initially, the models were scanned as reference casts using a lab scanner. The test group was involved in scanning the 1-mm and 4-mm implant models using an intraoral scanner in the following order: (1) scanning the 1-mm (T1; n = 10) and (2) 4-mm (T4; n = 10) implant groups with scan bodies connected to both fixtures in each model; (3) cut-out rescan (COR) in the 1-mm (COR1; n = 10) and (4) 4-mm (COR4; n = 10) models, leading to 40 digital files in standard tessellation language format. The mean absolute deviation (MAD), in terms of trueness and precision, between the experimental and control scans was assessed through the alignment of their respective datasets using three-dimensional analysis software. Two-way analysis of variance (ANOVA) and Levene's tests were used to analyze the data. RESULTS: The COR4 group exhibited the highest MAD, indicative of both trueness and precision (Mean ±SD: 55.659 ±34.802). In contrast, the T1 group demonstrated the lowest MAD (Mean ±SD: 43.225 ±19.237). However, the ANOVA analysis showed no significant influence of depth (P = 0.506) or type of scan (P = 0.442) on the MAD. Precision also did not differ significantly across groups (P = 0.071). CONCLUSIONS: The cut-out rescan approach demonstrated an accuracy comparable to that of the one-time scan method. CLINICAL SIGNIFICANCE: Digital intraoral scanning provides clinicians with a range of tools to navigate challenging conditions in which conventional methods may prove difficult, such as cases involving angled adjacent implants. In these scenarios, the cut-out rescan tool serves as a valuable resource, aiding clinicians in overcoming the challenges associated with impression-making owing to the convergence of placed implants.