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Current haptic devices are usually designed to provide one type of force feedback; however, most VR scenarios require versatile force feedback, which may require the integration of different devices to provide various types of forces. In addition, besides the main haptic effects caused by the forces, multiple types of oscillation may also commonly accompany them, which are crucial for improving VR realism and immersion. Therefore, we simulate versatile force feedback by rendering the corresponding types of oscillation as the effects caused by those forces. We take inertia and impact forces as examples in this paper, and achieve versatility using the proposed device, OsciHead, on a head-mounted display (HMD), instead of integrating different devices. By controlling elastic bands' elasticity and stored power, OsciHead uses two rotatable oscillators on both sides of the HMD, in order to render various multilevel and multidimensional oscillation feedback in 2D translation and 2D rotation directions on a head. In an exploratory study, we explored different scenarios in which multiple types of oscillation could be simulated by OsciHead. We then observed oscillation level distinguishability in two just-noticeable difference (JND) studies, and evaluated the oscillation type recognition rates in a recognition study. Based on the results, we performed a VR study, which verified that the inertia and impact feedback simulated by OsciHead enhances realism and achieves versatility.

There is controversial evidence on the best choice for root-end filling materials in follow-up periods and treatment protocols. The purpose of this study was to evaluate the effectiveness of different root-end filling materials in modern surgical endodontic treatment.A total of 16 studies with a minimum follow-up of 12-months were qualified to be reviewed, involving randomized control trials and observational studies in PubMed, Cochrane library and Scopus until September 1, 2021. The outcome of modern surgical endodontic treatment was assessed based on clinical and radiographic success. Direct comparisons were combined to estimate indirect comparisons, and the estimated effect size was analyzed using the odds ratio (OR). The comparative effectiveness of all materials for target outcomes were shown as P-score.Within this network meta-analysis, mineral trioxide aggregate (MTA) had superior effects among all root-end filling materials at 12-months follow-up. (MTA: OR, 2.03; 95% CI, 0.84-4.91; P-score, 0.86; reference material, gutta-percha). In further sensitivity analyses, MTA, calcium silicate-based root repair material (RRM) and super EBA cement (Super EBA) were associated with significantly higher success rates at 12-months follow-up. (MTA: OR, 5.62; 95% CI, 1.58-19.99; P-score, 0.88; RRM: OR, 5.23; 95% CI, 1.05-25.98; P-score, 0.74; Super EBA: OR, 3.99; 95% CI, 1.06-15.04; P-score, 0.54; reference material, gutta-percha).MTA remains the best choice for root-end filling materials of modern surgical endodontic treatment at the 12-month follow-up. Comparative randomized clinical trials in the long-term follow-up are warranted in future investigations.

The purpose of this study was to assess the prevalence of C-shaped canals in permanent mandibular second molars (SMs) and to determine whether its appearance was associated with the presence of distolingual root (DLR) in permanent mandibular first molars (FMs).Three hundred and eighty patients were qualified for evaluation of their FMs and SMs using cone beam computed tomography. The prevalence, distribution pattern, external root morphology, and the internal root canal anatomy of the examined molars were recorded and analyzed. Furthermore, the association between the root canal configurations of SMs and the appearance of DLR in FMs was also assessed.The prevalence of SMs with C-shaped root canals was 44.7%. The most common root canal configuration type of the one-rooted SMs with C-shaped anatomy was C3 (45.6%), followed by C2 and C1. The frequency of C-shaped canals in SMs was 45.4% in Non-DLR group, 52.8% in unilateral DLR group, and 33.9% in bilateral DLR group, respectively. Moreover, the prevalence of C-shaped root canals in SMs with the presence of bilateral DLRs in FMs was significantly lowered.The association between the presence of DLR in FMs and C-shaped canal configurations in neighboring SMs was surveyed, and the prevalence of C-shaped root canals in SMs with the presence of bilateral DLRs in FMs was found to be significantly lowered.

Introduction In this study, we examined the effect of mineral trioxide aggregate (MTA) on macrophage polarization and the potential involvement of Axl/nuclear factor kappa B (NF-κB) signaling in mediating the effect of MTA. Methods The human monocyte cell line THP-1 was cultured with MTA solution for 1, 2, or 3 days, and the population change of M2 macrophages was analyzed by flow cytometry. Expression of M2 cytokines was examined by enzyme-linked immunosorbent assay. Phagocytosis and angiogenesis-induction ability were also assayed. The involvement of Axl/NF-κB signaling in MTA-treated cells was examined by analyzing phosphorylation status of Axl, Akt, IKKα/β, and IκBα. Specific inhibitors for Axl/Akt/NF-κB signaling were added to MTA-treated THP-1 cells, and their cytokine expression change was examined. Results Flow cytometry analysis showed that MTA treatment increased CD206＋ cells in a time-dependent way. After MTA treatment, the expression of M2-related cytokines was up-regulated. MTA also enhanced phagocytic ability and the ability of THP-1 cells to induce angiogenesis. Treatment of MTA led to activate Axl/Akt/NF-kB signal axis by phosphorylation of Axl, Akt, IKKα/β, IκBα, and p65. In addition, MTA-induced interleukin 10, transforming growth factor beta, and vascular endothelial growth factor expression was suppressed as specific inhibitors were added. Conclusions Our findings indicate that MTA is able to induce macrophage polarization toward the M2 phenotype, with up-regulation of interleukin 10, transforming growth factor beta, and vascular endothelial growth factor, and that Axl/Akt/NF-κB signaling participates in this process. These results provide the cellular and molecular basis of MTA's anti-inflammatory action in clinical applications.

Background/purpose: Inadequacy to locate the second mesiobuccal canal (MB2) canal leads to the highest probability of endodontic failure in permanent maxillary first molars (PMFMs) and still remains a constant challenge for many clinicians. The aim of this study was to characterize the geometrical features between MB2 and other orifices of examined PMFMs using cone-beam computed tomography images. Materials and methods: A total of 108 teeth qualified in the cone-beam computed tomography image archives were enrolled in the present study. The intersecting point (T) was determined as the perpendicular line (h, altitude of triangle) projected from the vertex of the MB2 canal orifice to mesiobuccal canal orifice-palatal canal orifice line (MB1-P). We measured the geometric features of PMFMs with the MB2 canal, including the interorifice distances, area, altitude, and the ratio between the canal orifices. Results: The average interorifice distance was found to be 1.91±0.59 mm for MB1-MB2, 5.73±0.66 mm for MB1-P, and 4.11±0.79 mm for MB2-P, with significant gender difference for MB1-MB2 distance. For the MB1-T distance, a significant difference was found between genders (P=0.02), with males averaging 1.78±0.07 mm, and females 1.48±0.11 mm. For the MB1-P distance, the majorities of both genders were found in the 20–40% cut-off. A portion of the males exhibited a tendency towards the 40–80% cut-off, while females shifted in the reverse direction towards the 0–20% cut-off. Conclusion: In clinical scenarios, these anatomical characteristics of the root canals system could be beneficial to locating the MB2 canal. Keywords: cone-beam computed tomography, maxillary molar, morphology, root canal

Introduction The purpose of this study was to examine the frequency and bilateral consistency of distolingual roots (DLRs) in permanent mandibular first molars (PMFMs) and root canal configurations in PMFPs (permanent mandibular first premolars) and to determine the correlation between the root canal configurations of PMFPs with the appearance of DLRs in PMFMs. Methods A total of 932 cone-beam computed tomographic images of PMFMs and PMFPs were collected from 233 patients. The frequency and bilateral consistency of DLRs in PMFMs along with root canal configurations (root number and canal number) of PMFPs were recorded and evaluated ipsilaterally and contralaterally. Multivariable logistic regression analysis was used to evaluate the correlation between the root canal configurations of PMFPs with the appearance of DLRs in PMFMs. Results The prevalence of PMFMs with DLRs was 24.7%, and the incidence of complicated root canal configurations of PMFPs was 26.6%. The incidence of complicated root canal configurations of PMFPs was 19.6% in the non-DLR group, 37.2% in the unilateral DLR group, and 44.7% in the bilateral DLR group. After adjusting for categoric variables including sex, age, and side, the odds ratios for the frequency of complicated root canal configurations of PMFPs in the unilateral DLR and bilateral DLR groups compared with the non-DLR group were 2.472 (95% confidence interval, 1.434–4.263; P = .001) and 3.392 (95% confidence interval, 1.976–5.823; P Conclusions An increasing and corresponding trend between the presence of DLRs in PMFMs and complicated root canal configurations in PMFPs was noted in Taiwanese individuals. These results suggest that the clinicians should familiarize themselves with the anatomic variants of PMFMs and PMFPs before endodontic treatment.

To identify 100 top-cited articles published in periodontal journals and analyse the research trends by using citation analysis.100 top-cited articles published in periodontal journals were retrieved by searching the database of the ISI Web of Science and Journal Citation reports. For each article, the following principal bibliometric parameters: authorship, geographic and institute origin, manuscript type, study design, scope of study, and citation count of each time period were analysed from 1965 to 2015.The identified 100 top-cited articles were retrieved from five periodontal journals and citation counts were recorded between 262 and 1,693 times. For the institute of origin, the most productive institute, in terms of the number of 100 top-cited articles published, was the University of Gothenburg (Sweden) (n = 19), followed by the Forsyth Dental Center (USA) (n = 15). Most manuscripts were original research (n = 74), and the inflammatory periodontal disease (n = 59) was the most frequent topic studied. Interestingly, the trend of increase average citation reached significance for implantology (β = 26.75, P = 0.003) and systemic interactions (β = 29.83, P = 0.005), but not for inflammatory disease (β = -10.30, P = 0.248) and tissue regeneration (β = 9.04, P = 0.081). By using multivariable linear regression in a generalised linear model, suitable published journal (Journal of Clinical Periodontology), geographic regions (Europe), more intense international collaboration, adequate manuscript type (review article) and study design (systematic review) could be attributed to escalating average citation counts in implantology (all P0.05). However, for systemic interactions, only geographic region and study design were significantly associated with the increasing citation trend.These principal bibliometric characteristics revealed escalated trends in average citation count in implantology throughout time.

The aim of this study was to determine the prevalence of C-shaped canal configurations (CSs) and radicular grooves (RGs) in permanent mandibular first premolars (MPs) and to investigate the relevance of such complexities with the presence of distolingual roots (DLRs) in permanent mandibular first molars (MMs).A total of 800 pairs of MPs and MMs were investigated using a cone-beam computed tomographic system (NewTom 5G; QR srl, Verona, Italy). The frequency and symmetry of DLRs in MMs along with the occurrence of RGs and CSs in examined MPs were evaluated. Multivariable logistic regression analysis was applied to examine the correlation between the CSs of MPs with the appearance of DLRs in MMs.In the examined teeth, 23.0% of MMs had a DLR, whereas 16.6% of MPs had RGs and 12.5% of MPs had C-shaped canals. Although the most common canal configuration in MPs is the single canal (74.1%), the other 25.9% still possess complicated root canals. Of these MPs that have different canal configurations, 54.6% had 2 canals, whereas 44.4% had CSs. Specifically, the CS showed a high prevalence of C3 morphologies at 98.9% followed by C1 at 1.1%. A corresponding and increasing frequency was noted in CSs and RGs of MPs and MMs with DLRs (P .001). After adjusting for related categoric variables, the adjusted odds ratios for CSs of MPs in the bilateral DLR group compared with the non-DLR group was 3.294 (P .001).This study showed an increased appearance of CSs in MPs when DLRs were present in MMs in the Taiwanese population.

Background/purpose Condensing osteitis (CO) is a common lesion of the jaw bone. This study surveyed the occurrence of mandible CO and its distribution in the mandible in a Taiwanese population. Materials and methods Panoramic radiographs and clinical information of 1098 patients at the Dental Department of Tri-Service General Hospital (Taipei, Taiwan) were collected. The patient data were analyzed to determine the CO disease status, patient age distribution, sex, CO location in the mandible, and the status of the affected tooth. Results Seventy-five CO lesions were identified in 63 patients. The prevalence of CO in the mandible was 5.7%. Eight (10.7%) CO cases were associated with teeth that had crowns and/or bridges, 16 (21.3%) CO cases were associated with teeth that had caries or restorations; 22 (29.3%) CO cases were associated with teeth that had received root canal therapy, nine (12%) CO cases were associated with teeth with periodontal diseases, and 20 (26.7%) CO cases were located in the tooth extraction area. The percentage of females and males was 65.3% and 34.7%, respectively. Ten (13.3%) CO cases and 65 (86.7%) CO cases were identified in the premolar and molar area, respectively. The most common site of CO was in the first molar region. Conclusion In our study population, the CO lesion occurs more commonly in female patients who were in their 60s. The mandibular 1 st molar and teeth that had received root canal therapy had the highest association with CO. The CO distribution, as determined from this study, can provide valuable information for future clinical references.

The aim of this study was to assess the prevalence of complicated root canals in permanent mandibular central incisors (PMCIs) and its correlation with the presence of a distolingual root (DLR) in permanent mandibular first molars (PMFMs) using cone-beam computed tomographic imaging in a Taiwanese population.A total of 400 patients (800 pairs of PMCIs and PMFMs) were qualified for further analysis. The prevalence of DLRs in PMFMs along with root canal configurations of PMCIs were assessed at subject and tooth levels. Multivariable logistic regression analysis was used to evaluate the correlation between the root canal configurations of PMCIs with the existence of DLRs in PMFMs.The prevalence of PMFMs with DLRs and complicated root canal configurations in PMCIs was 23.0% and 15.6%, respectively. A significant difference in age (50 years vs ≥50 years) was found for complicated root canal configurations in PMCIs. The most prevalent root canal system in PMCIs was Vertucci type I (84.4%) followed by type III (13.5%). A positive correlation between the presence of DLRs in PMFMs and complicated root canal configurations in PMCIs was noted. After adjusting for categoric variables including sex, age, and side, the odds ratios for the occurrence of complicated root canal configurations of PMCIs in the unilateral DLR group and the bilateral DLR group compared with the non-DLR group were 2.13 and 2.53, respectively.The concurrent appearance of DLRs in PMFMs and complicated root canal morphology in PMCIs is prominent in Taiwanese individuals.

Introduction The aim of this study was to assess the root canal configurations in permanent mandibular lateral incisors (PMLIs) and the correlation between the root canal configurations of PMLIs with the appearance of a distolingual root (DLR) in permanent mandibular first molars (PMFMs) using cone-beam computed tomographic (CBCT) imaging. Methods A total of 1200 CBCT images (300 patients) of PMFMs and PMLIs were investigated. The frequency and distribution of DLRs in PMFMs along with root canal configurations of PMLIs were assessed ipsilaterally and contralaterally. Multivariable logistic regression analysis was used to evaluate the correlation between the root canal configurations of PMLIs with the appearance of a DLR in PMFMs. Results The prevalence of PMFMs with a DLR was 24.3%, and the incidence of complicated root canal configurations in PMLIs was 25.0%. The most prevalent root canal systems of PMLIs were Vertucci types I (75%) and III (23.0%). The incidence of complicated root canal configurations in PMLIs was 19.5% in the non-DLR group (ie, no DLR was found on either side of the PMFMs), 33.3% in the unilateral DLR (Uni-DLR) group (ie, a DLR was found in 1 of the PMFMs [the left or right side] and a DLR was not found on the other PMFM), and 39.8% in the bilateral DLR (Bil-DLR) group (ie, a DLR was found in both the right and left PMFMs). After adjusting for categoric variables including sex, age, and side, the odds ratios for the frequency of complicated root canal configurations of PMLIs in the Uni-DLR and Bil-DLR groups compared with the non-DLR group were 2.12 (P = .003) and 2.707 (P Conclusions The simultaneous appearance of DLRs in PMFMs and complicated root canal configurations in PMLIs is prominent in Taiwanese individuals. Clinicians should be aware of the correlation between the anatomic variants of PMFMs and PMLIs, which are important before endodontic treatment.

In this study, polystyrene/nanographite nanocomposite foams were made by different compounding methods, such as direct compounding, pulverized sonication compounding, and in situ polymerization, to understand the effect of the process variables on the morphology of the nanocomposites and their foam. The foam was made by batch foaming using CO2 as the blowing agent. Various foaming pressures and temperatures were studied. The results indicated that the cell size decreased and the cell morphology was improved with the advanced dispersion of the nanoparticles. Among the three methods, the in situ polymerization method provided the best dispersion and the resulting nanocomposite foam had the finest cell size and the highest cell density. In addition, adding nanoparticles as a nucleating agent can make foams of similar cell size and cell density at a much lower foaming pressure. This result can be explained by the classical nucleation theory. This discovery could open up a newroute to produce microcellular foams at a low foaming pressure. POLYM. ENG. SCI., 53:2061–2072, 2013. © 2013 Society of Plastics Engineers