Effect of Condensation Pressure on Microleakage of Mineral Trioxide Aggregate

Objective: The aim of this study was to assess the effect of condensation pressure on microleakage of mineral trioxide aggregate (MTA). Methods: This in vitro experimental study was conducted on 55 sound single-rooted straight-canal extracted human teeth. The teeth were sectioned at the cementoenamel junction (CEJ) and at 3 mm above the root apex. The roots were mounted in putty. Samples were then divided into three experimental groups (n=15) and positive and negative control groups (n=5). After filing of the root canals to file #50, white ProRoot MTA paste was prepared according to the manufacturer’s instruction and applied to the canals using condensation pressure of 0.44, 3.22 and 8.88 Mpa in groups one to three, respectively. After a 48-hour setting time, each root was connected to the fluid filtration system to measure microleakage. The mean microleakage rate of the groups was calculated and compared using one-way ANOVA and least significant difference test.Results: The mean microleakage with condensation pressure of 0.44, 3.22 and 8.88 MPa was 1.70×10-4, 1.17×10-4  and 0.48×10-4 µL/minute, respectively. One-way ANOVA showed that the mean microleakage rate was significantly different among the groups (P<0.05). The lowest microleakage was observed in condensation pressure of 8.88 MPa.Conclusion: Within the limitations of this study, the results showed that increase in condensation pressure decreased the rate of microleakage

The Effect of Canal Preparation with Four Different Rotary Systems on Formation of Dentinal Cracks: An In Vitro Evaluation

Introduction: Endodontic rotary systems may result in dentinal cracks. They may propagate to vertical root fracture that compromises the outcome of endodontic treatment. This study aimed to compare Neolix and Reciproc (single-file systems), Mtwo and ProTaper (conventional rotary systems) in terms of dentinal crack formation in root canal walls. Methods and Materials: This in vitro study was conducted on 110 extracted human single-rooted teeth. The teeth were randomly divided into four experimental groups (n=25) for root canal preparation with Neolix, Reciproc, Mtwo and ProTaper systems and two control groups (n=5). The first control group underwent root canal instrumentation with hand files while the second control group received no preparation and was only irrigated. After instrumentation, root canals were horizontally sectioned at 3, 6 and 9 mm from the apex and inspected under a stereomicroscope under 12× magnification for detection of cracks. The data were analyzed using chi-square, GEE test and Bonferroni tests (P<0.05). Results: No crack was found in the control groups. All rotary systems caused dentinal cracks. ProTaper, Reciproc, Mtwo and Neolix caused cracks in 92%, 80%, 68% and 48% of samples. ProTaper caused significantly more cracks than Neolix and Mtwo (P<0.05). No significant differences were noted between other groups (P>0.05). Conclusion: All rotary systems cause dentinal cracks and it is significantly different in apical, middle and coronal third of the root. Neolix appears to be a suitable alternative to other rotary systems since use of this single-file system saves time and cost and minimizes trauma to dentinal walls.Keywords: Dentinal Crack; Endodontics; Root Canal Preparation; Rotary Syste

Ethnoveterinary study of medicinal plants in Mehrabad village, Shahrbabak city, Kerman Province, Iran

Background & Aim: The Mehrabad village people in Shahrbabak and Province Kerman, Southeast Iran, have used medicinal plants and traditional remedies for ethnoveterinary practices, such as treating domestic animals during livestock breeding, since ancient times. Experimental: This study aimed to identify the plants used in their conventional ethnoveterinary methods and to propose suggestions for future conservation and sustainable use of this knowledge between 2019 and 2020. Data were collected from the local Buyi people through semi-structured interviews. Results: A total of 36 plant species, belonging to 25 families, used in ethnoveterinary practices by the Mehrabad people. During the survey, it was observed that the most prevalent families concerning the number of species were Apiaceae (13.51%), Followed by Papilionaceae (10.81%) followed by Chenopodiaceae, Lamiaceae, Liliaceae, Rosaceae, and Solanaceae (5.40% each), and the remaining families (2.70%) species. Sources and habits of medicinal plant types of growth that were herbs (60.97%), shrubs (24.39%), and trees (14.63%). Leaves (23.80%) were the most widely used plant parts for ethnoveterinary medicine, followed by Seeds (19.05), Aerial parts (19.05), and Fruits (16.66). Oral administration was the most common (70.45. %), followed by cutaneous (topical) administration (13.63%), chewing (9.09%), and smoking (6.81%). Older farmers had more excellent EVM knowledge than those who were younger. Recommended applications/industries: The information obtained in this study may help in the use and discovery of new drugs and further studies are needed to prevent the extinction of traditional veterinary knowledge (ethnoveterinary). Oral administration was the most common (42.76%), followed by cutaneous (topical) administration (36.18%)

Comparison of the root canal debridement ability of two single file systems with a conventional multiple rotary system in long oval-shaped root canals : in vitro study

This study sought to compare the root canal debridement ability of Neolix, Reciproc and ProTaper rotary systems in long oval-shaped root canals. Eighty five extracted single-rooted human teeth with long oval-shaped single root canals were selected and divided into three experimental groups(n=25) and one control group (n= 10). Root canals were filled with Vitapex radiopaque contrast medium and prepared with Neolix, Reciproc or ProTaper systems. The control group only received irrigation. Digital radiographs were obtained at baseline and postoperatively and subjected to digital subtraction. The percentage of reduction in contrast medium was quantified at 0-5 mm and 5-10 mm distances from the apex. The data were analyzed using one-way ANOVA and t-test. The mean percentage of the contrast medium removed was not significantly different in the 0-5mm segment among the three groups (P=0.6). In the 5-10mm segment a significant difference was found in this regard among the ProTaper and Reciproc groups (P=0.02) and the highest mean percentage of contrast medium was removed by ProTaper. But, difference between ProTaper and Neolix as well as Neolix and Reciproc was not significant. In Neolix (P=0.024) and Reciproc (P=0.002) systems, the mean percentage of the contrast medium removed from the 0-5mm segment was significantly greater than that in 5-10mm segment; however, this difference was not significant in ProTaper group (P=0.069). Neolix single-file system may be a suitable alternative to ProTaper multiple-file system in debridement of long oval shaped canals

Reconfigurable fully constrained cable-driven parallel mechanism for avoiding collision between cables with human

Productivity can be increased by manipulators tracking the desired trajectory with some constraints. Humans as moving obstacles in a shared workspace are one of the most challenging problems for cable-driven parallel mechanisms (CDPMs) that are considered in this research. One of the essential primary issues in CDPM is collision avoidance among cables and humans in the shared workspace. This paper presents a model and simulation of a reconfigurable, fully constrained CDPM enabling detection and avoidance of cable–human collision. In this method, unlike conventional CDPMs where the attachment points are fixed, the attachment points on the rails can be moved (up and down on their rails), and then the geometric configuration is adapted. Karush–Kuhn–Tucker method is proposed, which focuses on estimating the shortest distance among moving obstacles (human limbs) and all cables. When cable and limbs are close to colliding, the new idea of reconfiguration is presented by moving the cable’s attachment point on the rail to increase the distance between the cables and human limbs while they are both moving. Also, the trajectory of the end effector remains unchanged. Some simulation results of reconfiguration theory as a new approach are shown for the eight-cable-driven parallel manipulator, including the workspace boundary variation. The proposed method could find a collision-free predefined path, according to the simulation results

Cone-beam computed tomography assessment of the root canal morphology of primary molars

Abstract Background This study aimed to assess the root canal morphology of primary molars using cone-beam computed tomography (CBCT). Methods This cross-sectional study evaluated 60 maxillary and mandibular primary first and second molars on CBCT scans of patients retrieved from the archives of Hamadan School of Dentistry between 2018–2020. The teeth were evaluated regarding the number of roots and canals, canal type according to the Vertucci’s classification, and root surface concavities. Data were analyzed descriptively and by independent t-test. Results The most frequent number of canals and roots in the maxillary right and left first molars was 3 canals (60%) and 3 roots (80%). These values were 4 canals (80%) and 5 canals (50%) with 3 roots in the maxillary right and left second molars, respectively, 4 canals (100%) and 2 roots (50%), and 3 canals (60%) and 2 roots (50%) in mandibular right and left first molars, respectively, and 4 canals (92.3%) and 3 roots (61.5%) in mandibular right and left second molars. Vertucci’s type IV was the most common canal type in mesial and distal canals, type I was the most common in mesiobuccal, mesiolingual, distobuccal, and distolingual, and types I and II were the most common in the palatal canal. The maximum and minimum concavities were noted in the buccal (26.7%) and mesial (8.3%) surfaces, respectively. Conclusions A wide variation exists in the number of roots and canals of maxillary and mandibular primary molars, which calls for further attention in treatment of such teeth

Mannas, unique products of a dynamic insect-plant interaction: Biodiversity, conservation and ethnopharmacological considerations

Biodiversity keeping increases the flexibility, interaction and adaptation of different ecosystems with the environment which benefits all organisms, including humans. This diversity can be maintained through different paths including co-evolution between insects and plants. One of these unique interactions leads to the production of “Mannas” in Iran, which have biological and ethno-medicinal importance.Considering the crises of biodiversity and the rapid extinction of species, in this research, we aimed to review the latest scientific findings about mannas and their biological, medicinal and bio perspective considerations.Until August 2023, all English publications in Web of Science, Science Direct, PubMed, Google Scholar and Scopus, as well as Persian databases such as Magiran, Iranmedex, Medlib, SID were surveyed using various search terms such as manna, angabin, sweet secretions and plant-insect interference. Articles that studied manna production from plants or provided a comprehensive description of host plants and manna producing insects were included in the study.In total, out of more than 180 reviewed articles, 113 articles met the inclusion criteria and 7 known mannas (Bidkhesht, Gaz-e-Alafi, Gaz-e-Khansār, Gaz-e-Shahdād, Shirkhesht, Shekartigāl, and Taranjebin) have been explained here.This review deals with different aspects of special interactions between insects and plants that lead to the production of manna and presents different uses of manna from medicinal, ethnobotanical, health, conservation and bio perspective points of view. In addition, the changes in the population of manna-breeding insects and host plants are taken into consideration and influencing factors including loss of their growth conditions and climatic conditions, animal breeding in the region, inappropriate exploitation methods and host preference phenomenon which increase the risk of destruction of these natural products have been given. These mannas cannot be produced in any way, and maintaining their production conditions requires environmental care and providing necessary training

Effect of Low-Level Laser Therapy on Differentiation and Proliferation of Human Dental Pulp Stem Cells: A Systematic Review: Effect of LLLT on pulp stem cells

Introduction: Considering the positive impact of laser treatment on the proliferation of certain cell types, we opted to perform a systematic review aimed at evaluating the effects of laser therapy and photobiomodulation on the proliferation and differentiation of human dental pulp stem cells (hDPSCs).Methods: We included all research studies examining the impact of laser therapy on hDPSCs, without limitations on publication dates or article languages. The major international databases, including PubMed, ISI Web of Science, and Scopus, were searched from inception to April 2022 by the relevant keywords.Results: In total, 1886 studies were identified in the initial search from the mentioned databases and other sources. Finally, 17 relevant studies were included in the present systematic review after removing duplicates and non-relevant articles. The results indicated the useful effect of low-level laser therapy (LLLT) on the hDPSCs.Conclusion: The findings of this systematic review indicate the useful role of LLLT in cell therapy, proliferation, and differentiation associated with hDPSCs

The effect of low-dose aspirin on aspirin triggered lipoxin, interleukin 1 beta, and prostaglandin E2 levels in periapical fluid: a double-blind randomized clinical trial

Abstract Background The role of pro-resolving mediators in inflammation is a new concern in research. The effect of low-dose aspirin on production of a special kind of these mediators named aspirin triggered lipoxin (ATL) has been studied on different tissues. This randomized clinical trial evaluated the effect of low-dose aspirin on ATL and pro-inflammatory mediators’ level in periapical fluid of necrotic teeth with large lesions. Methods Twenty-four patients with necrotic pulp and periapical lesion were randomly assigned to low-dose aspirin and placebo groups. In the first appointment, canals were shaped up to F3 size and #40 K-file and cleaned with 10 milliliters 2.5% sodium hypochlorite and 17% Ethylenediaminetetraacetic acid. Periapical fluid was sampled by a paper cone. The tooth was temporized without any intracanal medication. Tablets were administered for 7 days, then the teeth were re-opened and the sampling were repeated. Interleukin-1 beta (IL-1β), prostaglandin E2 (PGE2) and ATL were analyzed by enzyme-linked immunosorbent assay. Data were analyzed with paired t-test using SPSS statistical software, version 21 (α = 0.05). Results A significant reduction in PGE2 and IL-1β was noted in the aspirin-treated group while an increase in ATL was observed (P  0.05). Conclusion Low-dose aspirin can influence the inflammatory process by reducing pro-inflammatory mediators such as PGE2 and IL-1β, as well as increasing the pro-resolving mediators such as ATL. Trial registration IRCT20191211045702N1

Effect of Nd:YAG and Diode Lasers on Apical Seal of Root Canals Filled with AH Plus and Mineral Trioxide Aggregate-Based Sealers

Objectives: Laser irradiation, as an adjunct to root canal preparation, may increase the success rate of endodontic treatments. This study aimed to assess the effect of neodymium-doped yttrium aluminum garnet (Nd:YAG) and diode lasers on the apical seal of the root canals filled with AH Plus® and mineral trioxide aggregate (MTA)-based sealers. Materials and Methods: This in-vitro experimental study was conducted on 96 single-rooted, single-canal extracted human teeth with closed apices. The root canals were prepared by using ProTaper® rotary instruments and were randomly divided into six groups (n=16): 940-nm diode laser and AH Plus® sealer (group 1), Nd:YAG laser and AH Plus® sealer (group 2), AH Plus® sealer (group 3), 940-nm diode laser and MTA-based sealer (group 4), Nd:YAG laser and MTA-based sealer (group 5), MTA-based sealer (group 6), as well as positive and negative control groups. A bacterial leakage model was used for microleakage assessment. Qualitative assessment was done by using a scanning electron microscope (SEM). Data were analyzed by two-way analysis of variance (ANOVA) at the significance level of 0.05. Results: There were statistically significant differences between the experimental and control groups (P=0.002). The laser-treated groups showed a lower apical microleakage compared to the non-laser-treated groups, although the difference was not statistically significant (P>0.05). No significant differences were noted between the two lasers in terms of the apical microleakage, irrespective of the type of sealer (P>0.05). Conclusions: Laser irradiation, as an adjunct to root canal preparation, has no significant effect on the level of apical microleakage