Comparison of Micro-Leakage around Temporary Restorative Materials Placed in Complex Endodontic Access Cavities: An In-Vitro Study

Objective: To compare mean micro-leakage around 3 types of temporary restorative materials in-vitro, when placed adjacent to permanent restorations (amalgam) in complex endodontic access cavities.STUDY Design: Randomized controlled trial.PLACE AND DURATION OF STUDY: Dental Clinics, Dental Laboratory and Research Laboratory at The Aga Khan University Hospital, Karachi, from January to June 2014.METHODOLOGY: After random allocation of 60 teeth into 3 experimental groups, each group had conventional class II cavities prepared and amalgam placed. After 14 days, endodontic access cavities were made in these teeth, followed by placement of Cavit, IRM and CLIP(depth of 4 mm each). After thermo-cycling and immersion in 0.5% methylene blue dye, the teeth were sectioned mesio-distally and observed under stereoscopic microscope (magnification x4) along 2 interfaces \u27a\u27 and \u27b\u27 (tooth-temporary restoration and temporary restoration-primary restoration), respectively. Depth of dye penetration was measured in millimeters.Results: IRM was leakiest at interface \u27a\u27, cavit had highest dye penetration at interface \u27b\u27, while CLIP exhibited least micro-leakage at \u27a\u27 and \u27b\u27. The mean dye penetration for Cavit was 0.80 ± 0.23 mm at \u27a\u27, and 2.24 ± 0.48 mm at \u27b\u27. For IRM, it was 1.82 ± 0.09 mm at \u27a\u27, and 0.44 ± 0.13 mm at \u27b\u27. For CLIP, the mean dye penetration was 0.43 ± 0.05 mm at \u27a\u27, and 0.32 ± 0.12 mm at \u27b\u27. The difference in dye penetration observed between the 3 groups at both interfaces was statistically significant.CONCLUSION: In a complex access cavity made adjacent to a pre-existing amalgam restoration, CLIP exhibits the least micro-leakage, followed by IRM and Cavit

Conservative management of invasive cervical resorption: a case Report

Abstract Invasive cervical resorption is a condition that affects the root surface area below the epithelial attachment. Multiple treatment modalities are advocated, involving exposure of the invasive defect, removal of the granulation tissue and sealing with various restorative materials. This report demonstrates conservative treatment of a patient presenting with peri-apical periodontitis in upper right central and lateral incisors, along with Class II invasive resorption defect cervically on the mesial aspect of the central incisor, as a result of trauma. As the patient was not willing for any surgical intervention, only ortho-grade root canal treatment was carried out in both teeth, with Calcium hydroxide as intra-canal medicament. At three year follow-up, the patient remains asymptomatic demonstrating radiographic evidence of infilling of defect with bone-like tissue. Within the limitations of this report, it was seen that this conservative method for halting the progression of invasive cervical resorption could be under taken in patients who are un-willing for surgical intervention or in whom surgery is contra-indicate

Efficient 2D Graph SLAM for Sparse Sensing

Simultaneous localization and mapping (SLAM) plays a vital role in mapping unknown spaces and aiding autonomous navigation. Virtually all state-of-the-art solutions today for 2D SLAM are designed for dense and accurate sensors such as laser range-finders (LiDARs). However, these sensors are not suitable for resource-limited nano robots, which become increasingly capable and ubiquitous nowadays, and these robots tend to mount economical and low-power sensors that can only provide sparse and noisy measurements. This introduces a challenging problem called SLAM with sparse sensing. This work addresses the problem by adopting the form of the state-of-the-art graph-based SLAM pipeline with a novel frontend and an improvement for loop closing in the backend, both of which are designed to work with sparse and uncertain range data. Experiments show that the maps constructed by our algorithm have superior quality compared to prior works on sparse sensing. Furthermore, our method is capable of running in real-time on a modern PC with an average processing time of 1/100th the input interval time.Comment: Accepted for 2022 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS

NearPM: A Near-Data Processing System for Storage-Class Applications

Persistent Memory (PM) technologies enable program recovery to a consistent state in a case of failure. To ensure this crash-consistent behavior, programs need to enforce persist ordering by employing mechanisms, such as logging and checkpointing, which introduce additional data movement. The emerging near-data processing (NDP) architec-tures can effectively reduce this data movement overhead. In this work we propose NearPM, a near data processor that supports accelerable primitives in crash consistent programs. Using these primitives NearPM accelerate commonly used crash consistency mechanisms logging, checkpointing, and shadow-paging. NearPM further reduces the synchronization overheads between the NDP and the CPU to guarantee persistent ordering by moving ordering handling near memory. We ensures a correct persist ordering between CPU and NDP devices, as well as among multiple NDP devices with Partitioned Persist Ordering (PPO). We prototype NearPM on an FPGA platform.1 NearPM executes data-intensive operations in crash consistency mechanisms with correct ordering guarantees while the rest of the program runs on the CPU. We evaluate nine PM workloads, where each work load supports three crash consistency mechanisms -logging, checkpointing, and shadow paging. Overall, NearPM achieves 4.3-9.8X speedup in the NDP-offloaded operations and 1.22-1.35X speedup in end-to-end execution

Bibliometric study on the literature related to dental research and education published in Journal of Pakistan Medical Association

Objective: To analyse characteristics of literature related to dental research and education published in a single medical journal, The Journal of Pakistan Medical Association.Method: The bibliometric study was conducted at the Sindh Institute of Oral Health Sciences, Jinnah Sindh Medical University from March till May 2020, and comprised electronic and hand search of scientific literature relevant to dentistry published in the Journal of Pakistan Medical Association from the first issue published in 1953 till March 2020. The selected articles were analysed for year of publication, field of study, type of article, institute and country of first author, number of authors and citation count. Keyword mapping was also carried out. Data was analysed using SPSS 19.Results: Of the 159 articles identified, 117(73.6%) were contributed from Pakistan. The most common specialties were Oral and Maxillofacial Surgery and Epidemiology with 20(12.6%) articles each, followed by Operative Dentistry and Endodontics 19(11.9%). Majority of articles were Original / Research 87(54.7%). The highest number of articles were published in 2019 26(16.35%). The Aga Khan University, contributed the most publications 30(18.9%), followed by Dow University of Health Sciences, 11(6.9%). Majority of the articles were contributed by three authors 48(38.4%). The top cited article was found to have 113 citations, followed by articles with 103 and 91 citations.Conclusions: The contribution of scientific papers related to dentistry and dental education in the Journal of Pakistan Medical Association was significant. With growth of dentistry as a discipline along with a parallel increase in the publication of dental research papers, it is imperative that a dedicated indexed journal for dental research be commenced