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The present study aims to compare the accuracy of metal sleeve-free 3D-printed computer-assisted implant surgical guides (MSF group) (n = 10) with metal sleeve-incorporated 3D-printed computer-assisted implant surgical guides (MSI group) (n = 10). Implants of diameter 4.0 mm and 5.0 mm were placed in the left second premolars and bilateral first molars, respectively, using a fully guided system. Closed-form sleeves were used in teeth on the left and open-form sleeves on the right. The weight differences of the surgical guides before and after implant placement, and angular deviations before and after implant placement were measured. Weight differences were compared with Student’s t-tests and angular deviations with Mann–Whitney tests. Cross-sectional views of the insert parts were observed with a scanning electron microscope. Preoperative and postoperative weight differences between the two groups were not statistically significant (p = 0.821). In terms of angular deviations, those along the mesiodistal direction for the left second premolars were significantly lower in the MSF group (p = 0.006). However, those along the mesiodistal direction for the bilateral molars and those along the buccolingual direction for all teeth were not significantly different (p > 0.05). 3D-printed implant surgical guides without metal sleeve inserts enable accurate implant placement without exhausting the guide holes, rendering them feasible for fully guided implant placement.

Background This study aimed to evaluate the trueness of implant placement with fully guided (FG) implant placement protocol versus partial-guided (PG) protocol. Methods The study recruited 16 fully edentulous patients with adequate maxillary bone volume. Each patient received six implants; three were planned for each side of the maxilla to support a full-arch implant-supported fixed prosthesis 3 (FP3). Patients were randomly assigned to one of two intervention groups: Group 1 (PG group), drilling was done using a surgical guide, but implant placement was done without the guide. In group 2 (FG group), both drilling and implant placement were done through the surgical guide. The spatial relationship (entry, apex, and angle deviation) between planned and placed implants was evaluated using pre- and postoperative CBCT data. Results The FG approach resulted in statistically significantly higher overall trueness in entry, apex, and angle deviation across multiple implant sites, with a statistically significant difference of 0.030, 0.013, and 0.036, respectively, though differences at individual implant sites were not consistently significant. Conclusion This trial supported the fully guided implant placement protocol for enhancing the trueness of implant positioning in the rehabilitation of edentulous maxillary arches. Clinicians should weigh the benefits of this increased trueness against practical considerations. Trial registration The current study was registered at ClinicalTrials.gov (NCT06542562) on August 5, 2024.

The accuracy of implant placement with a fully guided digital template can be influenced by many factors, such as arch difference, alveolar bone density, timing of implant placement and open flap. The purpose of this article was to evaluate the factors presumptively affecting the accuracy of implant placement assisted by the fully guided template in the anterior zone. In 40 patients with missing anterior teeth, a total of 52 implants were placed with tooth-borne, fully guided templates after CBCT evaluation, in West China Hospital of Stomatology, Sichuan University. After overlapping the pre-and post-operative DICOM data, measurements were taken in the dental implant planning software (Nobel Clinician®) to calculate linear and angular deviations between virtual placement plan and actual implant placement. Grouping was categorized according to three factors that possibly have an influence on accuracy: arch type (maxilla/mandible), timing of implant placement (immediate/delayed), surgical technique (open flap/flapless). The data was analyzed with independent sample t-test (p < 0.05). The results showed that the apical, coronal, depth and angular mean deviations of implant positions in anterior zone were 1.13 ± 0.39 mm, 0.86 ± 0.33 mm, 0.41 ± 0.66 mm, 3.32 ± 1.65° with the fully guided templates. The accuracy at apex level, coronal level and the angulation were similar between the maxilla and mandible, and the magnitude of all four deviations between immediate and delayed implantation, open flap and flapless technique were small. No statistically significant difference was observed (p > 0.05). Whereas there was significant difference in depth deviation between maxilla and mandible (p < 0.05). Conclusively, the implant site, alveolar bone density, timing of implant placement and surgical techniques merely compromise the implant placement accuracy under the assistance of a fully guided template.

An increase in the number of implants placed has led to a corresponding increase in the number of complications reported. The complications can vary from restorative complications due to poor placement to damage to collateral structures such as nerves and adjacent teeth. A large majority of these complications can be avoided if the implant has been placed accurately in the optimal position. Therefore, the aim of this in vitro pilot study was to investigate the effect of freehand (FH) and fully guided (FG) surgery on the accuracy of implants placed in close proximity to vital structures such as the inferior alveolar nerve (IAN). Cone-beam computed tomography (CBCT) and intraoral scans of six patients who have had previous dental implants in the posterior mandible were used in this study. The ideal implant position was planned. FG surgical guides were manufactured for each case. In this study, the three-dimensional 3D printed resin models of each of the cases were produced and the implants placed using FG and FH methods on the respective models. The outcome variables of the study, angular deviations were calculated and the distance to the IAN was measured. The mean deviations for the planned position observed were 1.10 mm coronally, 1.88 mm apically with up to 6.3 degrees’ angular deviation for FH surgery. For FG surgical technique the mean deviation was found to be at 0.35 mm coronally, 0.43 mm apically with 0.78 degrees angularly respectively. The maximum deviation from the planned position for the apex of the implant to the IAN was 2.55 mm using FH and 0.63 mm FG. This bench study, within its limitations, demonstrated surgically acceptable accuracy for both FH and FG techniques that would allow safe placement of implants to vital structures such as the IAN when a safety zone of 3 mm is allowed. Nevertheless, a better margin of error was observed for FG surgery with respect to the angular deviation and controlling the distance of the implant to the IAN using R2 Gate® system.

Purpose To evaluate early versus conventional loading in immediate implants for molars. This study aims to answer the following PICO (Patient, Intervention, Comparison, and Outcome) question: In patients over 18 years of age, does early loading of immediately placed implants in molar areas result in a similar implant survival rate and marginal bone loss as conventional loading? Methods Twenty-seven patients (15 women and 12 men) received a total of 30 implants immediately after molar extraction. The surgical treatment protocol entailed atraumatic tooth extraction without flap elevation. Non-invasive quantitative analyses were used to assess implant stability. After an uneventful healing period, the 30 implants were restored with screw-retained monolithic zirconia prosthesis, half of which after 6 weeks (G1) and the other half after 3 months (G2). Results Regarding the survival rate, the Kaplan–Meier and log-rank test showed that there was no statistically significant difference between both groups ( p  = 1). Implant stability quotient at the prosthetic phase of both groups (6 weeks in G1 and 3 months in G2) revealed no statistically significant difference (G1 RFA74.4 (SD 5.54) − DCA 79.07 (SD 5.75))/G2 RFA 73.67 (SD 5.7), − DCA78.93 (SD 4.48). Conclusions Early loading of immediately placed implants in molar sites is considered a predictable treatment modality provided that ideal implant position and adequate insertion torque are achieved.

ABSTRACT A geometric approach is presented that allows in‐office planning with linear and angle corrections and surgical guide fabrication, simplifying the process when treating a fully edentulous arch.

This paper investigates the design of an attitude autopilot for a dual-channel controlled spinning glide-guided projectile (SGGP), addressing model uncertainties and external disturbances. Based on fixed-time stable theory, a disturbance observer with integral sliding mode and adaptive techniques is proposed to mitigate total disturbance effects, irrespective of initial conditions. By introducing an error integral signal, the dynamics of the SGGP are transformed into two separate second-order fully actuated systems. Subsequently, employing the high-order fully actuated approach and a parametric approach, the nonlinear dynamics of the SGGP are recast into a constant linear closed-loop system, ensuring that the projectile's attitude asymptotically tracks the given goal with the desired eigenstructure. Under the proposed composite control framework, the ultimately uniformly bounded stability of the closed-loop system is rigorously demonstrated via the Lyapunov method. Validation of the effectiveness of the proposed attitude autopilot design is provided through extensive numerical simulations.

The axial loading in rockbolts changes due to stress redistribution and rheology in the country rock mass. Such a change may lead to debonding at rockbolt to grout interface or rupture of the rockbolt. In this study, based on laboratory experiments, ultrasonic guided wave propagation in fully grouted rockbolt under different pull-out loads was investigated in order to examine the resultant debonding of rockbolt. The signals obtained from the ultrasonic monitoring during the pull-out test were processed using wavelet multi-scale analysis and frequency spectrum analysis, the signal amplitude and the amplitude ratio ( Q ) of low frequency to high frequency were defined to quantify the debonding of rockbolt. In addition to the laboratory test, numerical simulation on the effect of the embedment lengths on ultrasonic guided wave propagation in rockbolt was conducted by using a damage-based model, and the debonding between rockbolt and cement mortar was numerically examined. It was confirmed that the ultrasonic guided wave propagation in rockbolt was very sensitive to the debonding because of pull-out load, therefore, the critical bond length could be calculated based on the propagation of guided wave in the grouted rockbolt. In time domain, the signal amplitude in rockbolt increased with pull-out load from 0 to 100 kN until the completely debonding, thus quantifying the debonding under the different pull-out loads. In the frequency domain, as the Q value increased, the debonding length of rockbolt decreased exponentially. The numerical results confirmed that the guided wave propagation in the fully grouted rockbolt was effective in detecting and quantifying the debonding of rockbolt under pull-out load.

Mobile health (mHealth) apps offer unique opportunities to support self-care and behavior change, but poor user engagement limits their effectiveness. This is particularly true for fully automated mHealth apps without any human support. Human support in mHealth apps is associated with better engagement but at the cost of reduced scalability. This work aimed to (1) describe the theory-informed development of a fully automated relaxation and mindfulness app to reduce distress in people with cancer (CanRelax app 2.0), (2) describe engagement with the app on multiple levels within a fully automated randomized controlled trial over 10 weeks, and (3) examine whether engagement was related to user characteristics. The CanRelax app 2.0 was developed in iterative processes involving input from people with cancer and relevant experts. The app includes evidence-based relaxation exercises, personalized weekly coaching sessions with a rule-based conversational agent, 39 self-enactable behavior change techniques, a self-monitoring dashboard with gamification elements, highly tailored reminder notifications, an educational video clip, and personalized in-app letters. For the larger study, German-speaking adults diagnosed with cancer within the last 5 years were recruited via the web in Switzerland, Austria, and Germany. Engagement was analyzed in a sample of 100 study participants with multiple measures on a micro level (completed coaching sessions, relaxation exercises practiced with the app, and feedback on the app) and a macro level (relaxation exercises practiced without the app and self-efficacy toward self-set weekly relaxation goals). In week 10, a total of 62% (62/100) of the participants were actively using the CanRelax app 2.0. No associations were identified between engagement and level of distress at baseline, sex assigned at birth, educational attainment, or age. At the micro level, 71.88% (3520/4897) of all relaxation exercises and 714 coaching sessions were completed in the app, and all participants who provided feedback (52/100, 52%) expressed positive app experiences. At the macro level, 28.12% (1377/4897) of relaxation exercises were completed without the app, and participants' self-efficacy remained stable at a high level. At the same time, participants raised their weekly relaxation goals, which indicates a potential relative increase in self-efficacy. The CanRelax app 2.0 achieved promising engagement even though it provided no human support. Fully automated social components might have compensated for the lack of human involvement and should be investigated further. More than one-quarter (1377/4897, 28.12%) of all relaxation exercises were practiced without the app, highlighting the importance of assessing engagement on multiple levels.

Background/Objectives: Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) using a fully covered self-expandable metal stent (FCSEMS) is an alternative to endoscopic retrograde cholangiopancreatography for biliary drainage; however, FCSEMSs may cause intrahepatic bile duct (IHD) obstruction and cholangitis. In this study, we developed an FCSEMS with multiple self-made side holes at its tip and evaluated its safety and efficacy. Methods: This retrospective study included 100 patients who underwent EUS-HGS with FCSEMS placement between April 2022 and October 2023. Fifty patients received a conventional FCSEMS, and 50 received an FCSEMS with multiple self-made side holes. Technical and clinical success, residual contrast in the IHD, recurrent biliary obstruction (RBO), and adverse events (AEs) were then evaluated. The clinical success rates were 98% and 90% for the side hole and conventional FCEMS groups, respectively. The amount of residual contrast in the IHD was lower in the side hole group (0% vs. 12%, p = 0.027). RBO incidence was significantly lower in the side hole group (8% vs. 30%, p < 0.001), with migration as the primary cause in the conventional group. Early AEs, including segmental cholangitis, occurred only in the conventional group. During reintervention, all stents were safely removed. Conclusions: The FCSEMSs with multiple side holes reduced IHD occlusion and cholangitis, improving biliary drainage and safety. Further studies are needed to confirm these findings.