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1.
BMC Med Educ ; 24(1): 282, 2024 Mar 13.
Article in English | MEDLINE | ID: mdl-38481299

ABSTRACT

BACKGROUND: Contemporary undergraduate dental education aims to equip the dental students with clinical competence, empathy, and professionalism to enable them to deliver safe and effective dental care to the communities. The purpose of this study was to assess the self-reported preparedness of final year dental students and interns at three Saudi dental institutions, using the pre-validated Dental Undergraduates Preparedness Assessment Scale (DU-PAS). METHODS: A cross-sectional study design was employed to assess the self-reported preparedness of the participants using the DU-PAS. Following ethics approval, a probability sampling technique was used to recruit undergraduate dental students and interns from three dental institutions in Saudi Arabia. The data was collected online on Google Forms and all participants provided their consent to participate in the study prior to providing their responses to DU-PAS. RESULTS: Responses were received from 397 participants including 171 males and 226 females yielding a response rate of 60.3%. The total mean score of the participants was 81.85 ± 13.11. Although higher scores were reported in males, the interaction between gender and DU-PAS scores were not significant. Interaction between DU-PAS scores and stage of education showed significant effect of the stage of education with interns reporting higher overall scores. The participants reported that they were able to perform most clinical procedures independently. However, low confidence was reported in performing multi-rooted endodontics, fabrication of removable dentures and orthodontic assessment. The participants also expressed their confidence in a wide range of behavioural attributes related to communication, teamworking and professionalism. However, lack of experience was noted in referral for oral cancer, interpreting research, and evaluation of new dental products using an evidence-based approach. CONCLUSION: The study provides useful insights into the self-reported preparedness of undergraduate dental students and interns in three dental institutions. While the overall preparedness of the participants was comparable to their international peers, the findings underscore the need for further enhancements to the teaching and training of undergraduate students particularly in multirooted endodontics, removable prosthodontics and orthodontics.


Subject(s)
Endodontics , Students, Dental , Male , Female , Humans , Self Report , Saudi Arabia , Cross-Sectional Studies , Endodontics/education
2.
Materials (Basel) ; 17(5)2024 Feb 21.
Article in English | MEDLINE | ID: mdl-38473470

ABSTRACT

The surface roughness (Ra) of indirect computer-aided design/computer-aided manufacturing (CAD/CAM)-fabricated dental restorations is crucial for their long-term durability. This study intended to evaluate the Ra of five different types of contemporary indirect CAD/CAM restorative materials with varying compositions that were glazed and finished/polished. A total of 75 specimens, disc-shaped (10 mm × 2 mm), were obtained from five materials (n = 15) (Tetric CAD, IPS e.max CAD, IPS e.max ZirCAD, CELTRA Duo, and Vita Enamic) and fabricated by CAD/CAM. One of the two surfaces for each specimen was subjected to glazing, while the other surface was subjected to finishing/polishing. The Ra of the two surfaces in micrometers (µm) was evaluated using a Profilometer, while the surface topography was examined using a scanning electron microscope. Using SPSS, the Kruskal-Wallis, post hoc Conover, and Mann-Whitney tests were used to statistically evaluate the data. A comparison of the Ra for the finished/polished surfaces of the five test materials showed significant differences (p < 0.0001). Among the finished/polished surfaces, the mean rank values of Vita Enamic were significantly higher than the other four test materials (p < 0.0001). A comparison of the Ra of glazed surfaces among the five study materials revealed significant differences (p < 0.0001). The Ra for the IPS e.max ZirCAD material was significantly higher than the rest of the four materials (p < 0.001). A comparison of the Ra for two types of surface conditioning within each of the five test materials showed a significant difference (p < 0.05). Only for IPS e.max ZirCAD was the Ra of the glazed surface significantly higher than the finished/polished surface (p < 0.0001). Significant variations in the surface roughness (Ra) were exhibited between the finished/polished and glazed surfaces of the five test materials. Hybrid ceramics showed the highest Ra values for the finished/polished surfaces, and zirconia exhibited the highest Ra values among the glazed surfaces among the tested materials. The Ra values of either finished/polished or glazed surfaces of the test materials were within the clinically acceptable range (0.2-0.5 µm), except for the glazed surface of the zirconia ceramics (0.84 µm).

3.
Medicina (Kaunas) ; 59(11)2023 Nov 17.
Article in English | MEDLINE | ID: mdl-38004074

ABSTRACT

Background and Objectives: An understanding of the anatomical complexity of teeth is a significant factor for a successful endodontic treatment outcome. The aim of this study was to explore the frequency and pattern of distribution of radix entomolaris (RE) in mandibular first molars (MFMs) of a Saudi Arabian subpopulation using CBCT scans. Materials and Methods: This study was conducted at dental clinics of Qassim University from February to May 2023 by evaluating CBCT scans that were previously obtained for diagnostic purposes. Scans of Saudi national patients with bilaterally present MFMs and fully formed root apices were included. Conversely, scans with one/or two missing MFMs, MFMs with incomplete root apices, full- or partial-coverage prosthesis, endodontic treatment, and associated radicular resorption were excluded from study. A total of 303 CBCT scans with 606 bilateral MFMs were analyzed by two calibrated evaluators for the presence of, and type according to Song's typolgy of RE. The data were analyzed using SPPS-24. The descriptive variables were documented as frequencies and percentages. The chi-square test was used to determine the association between the prevalence of RE with the gender, jaw side and age group. Both inter-rater and intra-rater agreements were estimated for detecting and classifying RE using Cohen's kappa test. Results: The sample had 63.7% males and 36.3% females. The prevalence of RE was 6.6%, with Song's type III (57.5%) as the most common variant. Absolute agreement was noted between the raters about the presence of RE and very strong agreement was noted for the classification of the RE. Conclusions: RE is an uncommon finding among the mandibular first molars of the Saudi population without any gender and quadrant predilection. The clinicians' knowledge of the presence and Song's type of RE may contribute towards the enhancement of endodontic treatment outcomes.


Subject(s)
Mandible , Tooth Root , Male , Female , Humans , Saudi Arabia/epidemiology , Tooth Root/diagnostic imaging , Mandible/diagnostic imaging , Molar/diagnostic imaging , Cone-Beam Computed Tomography
4.
Medicina (Kaunas) ; 59(10)2023 Oct 16.
Article in English | MEDLINE | ID: mdl-37893558

ABSTRACT

Background and Objectives: Lidocaine Hydrochloride has been the standard choice for local anesthesia in dentistry and Articaine's unique structure and growing popularity make it a viable alternative. Due to contradictory results in prior research and a scarcity of trials conducted in the Pakistani population, this study aims to compare the anesthetic efficacy of Lidocaine with Articaine for inferior alveolar nerve blocks in patients with symptomatic irreversible pulpitis. Materials and Methods: This double-blinded, randomized controlled trial included 152 patients who were selected by consecutive non-probability sampling. The participants included patients who presented with symptomatic irreversible pulpitis in mandibular posterior teeth (molars and premolars) and depicted normal apical tissue radiographically. The patients were equally and randomly divided into two groups. The control group received 2% Lidocaine Hydrochloride injections, and the experiment group received 4% Articaine Hydrochloride injections. Participants scored their pain on the HP-VAS both before and after the administration of anesthesia. A value of 54 mm or less on the scale indicated effective anesthesia. The data obtained were analyzed using SPSS. Chi-square test was applied to analyze data for statistical significance. Results: There was no statistically significant difference in the efficacy of the two anesthetic agents. During access cavity preparation, Lidocaine demonstrated a success rate of 93%, whereas Articaine exhibited a slightly higher success rate of 97%. During initial instrumentation, the success rates for Lidocaine and Articaine were 72% and 71%, respectively. This suggests that both Lidocaine and Articaine were effective in achieving anesthesia during the dental procedure in patients with symptomatic irreversible pulpitis, with Articaine showing a slightly better success rate, although the difference was not statistically significant. Conclusions: The anesthetic efficacy of Articaine is similar to that of lidocaine in subjects with symptomatic irreversible pulpitis. Hence, Articaine can serve as an alternative to Lidocaine for local anesthesia administration in dentistry.


Subject(s)
Anesthesia, Dental , Nerve Block , Pulpitis , Humans , Carticaine/therapeutic use , Lidocaine/therapeutic use , Anesthetics, Local/therapeutic use , Pulpitis/drug therapy , Pulpitis/surgery , Tooth Apex , Nerve Block/methods , Mandibular Nerve , Double-Blind Method
6.
Materials (Basel) ; 16(11)2023 May 26.
Article in English | MEDLINE | ID: mdl-37297113

ABSTRACT

The use of vaping or electronic cigarette devices (ECDs) has recently increased as an alternative to conventional tobacco smoking products. By recording the CIELAB coordinates (L*a*b*) and computing the total color difference (ΔE) values using a spectrophotometer, the effect of ECDs on contemporary aesthetic dental ceramics was investigated in this in-vitro study. A total of seventy-five (N = 75) specimens from five different (n = 15) dental ceramic materials (Pressable ceramics (PEmax); Pressed and layered ceramics (LEmax); Layered zirconia (LZr); Monolithic zirconia (MZr) and Porcelain fused to metal (PFM)) were prepared and exposed to aerosols produced by the ECDs. The color assessment was performed using a spectrophotometer at six time intervals (0 = baseline; 250-puff exposures; 500-puff exposures; 750-puff exposures; 1000-puff exposures; 1250-puff exposures; and 1500-puff exposures). By recording L*a*b* and computing total color difference (ΔE) values, the data were processed. A one-way ANOVA and Tukey procedure for pairwise comparisons were used to assess color differences between tested ceramics (p < 0.05). All test materials demonstrated significant color differences (ΔE) after exposure to vaping (p < 0.05). The LZr group displayed noticeably high ΔE values at all the distinct puff exposure intervals, with the highest ΔE value of (13.67) after 1500 puffs. The lowest (ΔE) values were observed in the PFM group after 250 and 500 puffs (0.85 and 0.97, respectively). With the exception of the group PEmax (p = 0.999), all groups produced readings of "ΔE" that indicated significant differences (p < 0.05) at various degrees of puff exposures. ECDs can noticeably alter the color of the dental ceramics affecting the esthetics of the patients. All the materials tested demonstrated significant color changes (ΔE > 3.33) above the clinically acceptable threshold, except for the PFM and PEmax group (ΔE < 3.33) which showed color stability after exposure to the ECDs.

7.
Polit Stud Rev ; 21(1): 190-209, 2023 Feb.
Article in English | MEDLINE | ID: mdl-37038605

ABSTRACT

Why have some countries been more successful in their COVID-19 vaccine rollouts than others? Despite efforts by governments to vaccinate their adult populations against COVID-19, vaccination rates remain irregularly low in some countries. We suggest that a crucial piece of this puzzle lies in resistance against government directives from the public due to civil liberty protections. Countries with greater protections for civil liberties can be expected to have lower vaccinations administered than countries with fewer protections, as the public enjoys a sense of freedom regarding their private lives. In such countries, de jure constraints on government policies are complemented by the fear of public backlash, even in crises; consequently, beyond structural limitations, governments with high levels of civil liberty protections face an additional hurdle in managing the COVID-19 crisis. Evidence for this hypothesis is presented for 153 countries by combining civil liberty scores with newly available data on COVID-19 vaccinations.

8.
Saudi Dent J ; 34(8): 751-756, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36407754

ABSTRACT

Delivering quality education to students with fair assessment strategies is a key indicator of an excellent educational institution. The present study explored the impact of the COVID-19 pandemic on the academic performance of dental students in terms of the evaluations/grades awarded to them before and during the pandemic. The targeted groups were dental students, studying in the third year of 2018-2019 and 2020-2021 academic years. The sample size included all male and female students who enrolled and completed the following courses: pre-clinical fixed prosthodontics (SDS333), pre-clinical removal prosthodontics (SDS323), clinical operative dentistry-1 (RDS313), and pre-clinical endodontics (RDS323). Evaluations for students who did not complete the requirements were not included in the statistical analysis. Paired sample statistics were used for comparisons between the different groups at p < 0.05. Results revealed statistically significant differences (p ≤ 0.05) for all the course pairs. It was found that students' grades for all the courses during the pandemic year were higher compared to the grades before the pandemic. While female students demonstrated the highest mean difference (6.13) before and during the pandemic year for RDS323, males demonstrated the highest mean difference (8.14) for SDS323. However, both male and female students demonstrated the lowest mean difference (0.25 and 2.03, respectively) for SDS333. The grades were higher during the COVID-19 pandemic. Overall, female students achieved higher grades than male students.

9.
Materials (Basel) ; 15(19)2022 Sep 30.
Article in English | MEDLINE | ID: mdl-36234146

ABSTRACT

(1) Background: An ideal bond strength between endodontic posts and root canal dentin is essential for optimal retention and good prognosis. This study aimed to evaluate the push-out bond strength (PBS) of prefabricated fiber and metal posts, luted with resin cement to natural dentin. (2) Methods: Extracted premolars with similar root dimensions were assigned into two groups of 30 each for the metal and fiber posts. Teeth were mounted in acrylic blocks exposing 2 mm of the coronal root. Teeth were subjected to endodontic treatment and post-space preparations. Two groups were further subdivided into three sub-groups (n = 10) according to the size of the posts (# 4, 5 and 6). Posts were cemented with resin cement. Specimens were sectioned into 4 mm slices and subjected to the PBS test. (3) Results: The mean PBS was similar for the metal and fiber posts bonded with resin cement, showing a statistically significant result. An increase in post size increased the bond strength initially, but a further increase in size did not show any marked difference. A total of 71.66% of tested specimens failed with the adhesive failure mode. (4) Conclusions: Metal posts showed slightly higher retention compared to the fiber posts, although the p-value was similar for both types. An increase in the size of posts showed increased retention. The most common mode of failure was adhesive failure between cement and dentin.

10.
J Ayub Med Coll Abbottabad ; 34(2): 357-359, 2022.
Article in English | MEDLINE | ID: mdl-35576302

ABSTRACT

BACKGROUND: Catatonia is a psychomotor syndrome characterized by numerous clinical features, a few being stupors which is the most common sign, posturing, forced grasping, echopraxia, etc. There have been cases documented in the literature of Catatonia occurring with COVID-19. This article will focus on the complete and brief overview of catatonia observed in patients with COVID-19 infection. METHODS: We outline the evidence of the pathophysiology of COVID-19 in the CNS system, the effect of the virus in inducing catatonia, and its outcome. The literature used in the article is mostly case reports from different parts of the world thus; we have generalized our review taking into consideration multiple factors. RESULTS: In patients with COVID-19, neuropsychiatric manifestations are very commonly appreciated. Catatonia has been documented in many patients along with respiratory symptoms such as fever, shortness of breath, and cough. There are multiple etiologies associated with this presentation which have been discussed in detail in this article. In many patients, there was no history of any psychiatric illness. The timing of presenting with catatonic features was also different for different individuals. CONCLUSIONS: COVID-19 has been believed to contribute to the presentation of catatonia. There is no specific timeline between the onset of symptoms and the presence of COVID-19 infection. However, coronavirus can be responsible in a few ways for inducing catatonia in patients with or without any previous psychiatric illness. Therefore, COVID-19 should be considered as one of the major factors in this complex psychiatric disease, catatonia.


Subject(s)
COVID-19 , Catatonia , COVID-19/complications , Catatonia/diagnosis , Catatonia/etiology , Catatonia/psychology , Humans
11.
Biomed Res Int ; 2022: 1897705, 2022.
Article in English | MEDLINE | ID: mdl-35103235

ABSTRACT

BACKGROUND: You Tube is one of the most commonly used online sources for sharing information and knowledge. Academic topics or clinical data shared on this platform is not peer reviewed or evaluated by subject specialists for accuracy. No study was found in the literature examining the validity of crown preparation videos available at this platform. OBJECTIVE: To evaluate the authenticity of the content and quality of the crown preparation videos uploaded on the YouTube. METHODS: The systematic search for YouTube videos was carried out over a period of one year from January 2020 until February 2021. The keywords or phrases and tags used were crown preparation, PFM crown preparation, all ceramic crown preparation, and dental crown preparation. The videos were shortlisted on the basis of inclusion and exclusion criteria to select educationally useful videos in terms of content and quality. RESULTS: Three subject specialists evaluated the videos on crown preparation three times to shortlist only 12 (11%) educationally useful videos out of 109 relevant videos. These 12 videos met the preset inclusion criteria. CONCLUSION: Although YouTube is the most popular social media platform used as the source of information by the students, the majority of uploaded content lacks authenticity. This study found that crown preparation videos uploaded by the faculty members or subject specialists can be considered as the reliable source.


Subject(s)
Crowns , Social Media , Tooth Preparation, Prosthodontic , Video Recording , Humans
12.
Article in English | MEDLINE | ID: mdl-35010815

ABSTRACT

The aim of this study was to compare patients' satisfaction and quality of life (QoL) when using implant overdentures vs. conventional dentures. The QoL of Saudi patients who were provided mandibular implant-supported overdentures was assessed using a structured questionnaire. Overall satisfaction; ability to speak, eat, and chew food; comfort; esthetics; stability; and satisfaction of general oral health were measured. A total of 48.3% vs. 6.9% were, overall, very satisfied with their implant overdentures and conventional dentures, respectively. A total of 37.9% of the patients were very satisfied regarding speaking with their implant overdentures vs. 17.2% with conventional dentures. Furthermore, 41.4% were very comfortable with their implant overdentures vs. 5.2% were very comfortable using conventional dentures. However, only 15.5% were very satisfied with the esthetics of the conventional dentures compared to 43.1% being satisfied with implant overdentures. Only 1.7% were very satisfied with the stability of conventional dentures vs. 44.8% being satisfied using implant overdentures. About 8.6% of the candidates were very satisfied regarding chewing food with conventional dentures vs. 36.2% being very satisfied using implant overdentures. Approximately 10.3% were very satisfied with their general oral health using conventional dentures compared to 29.3% being very satisfied using implant overdentures. Mandibular implant overdentures had a strong impact on patients' quality of life over conventional complete dentures and should be considered the minimum standard of care provided to completely edentulous patients.


Subject(s)
Denture, Overlay , Quality of Life , Denture, Complete , Humans , Mastication , Patient Satisfaction , Saudi Arabia
13.
Environ Sci Pollut Res Int ; 29(23): 34055-34074, 2022 May.
Article in English | MEDLINE | ID: mdl-35034299

ABSTRACT

Recently, the Japanese government has announced the national objective of turning the economy of Japan carbon-neutral by 2050. This declaration has therefore enhanced the imperativeness of replacing the use of unclean energy with cleaner alternatives so that the carbon-neutrality agenda can be attained in due course. Against this backdrop, this study aims to assess whether enhancing government investments in research and development for developing clean energy can help Japan curb its carbon dioxide emission figures. In addition, the analysis also controls for the environmental effects of clean electricity output, economic growth, international trade, financial globalization, and urbanization on Japan's carbon dioxide emission figures. The cointegration test results confirm long-run relationships between all these variables. Besides, the regression results showed that scaling-up research and development-related investments for clean energy development reduces carbon dioxide emissions only in the long run. Similar emission-inhibiting impacts are also evidenced to be associated with greater output of clean energy-fired electricity. Moreover, it is also observed that higher clean energy development-related investments play a mediating role in amplifying the carbon dioxide emission-reducing effects of clean electricity generation in the long run. In addition, economic growth is seen to dampen environmental quality by triggering higher emissions of carbon dioxide both in the short and long run. Simultaneously, enhancing openness to international trade and greater urbanization is found to boost the carbon dioxide emission figures of Japan. However, an influx of foreign direct investments is not observed to influence carbon dioxide emissions in Japan, neither in the short run nor in the long run. Accordingly, concerning the achievement of carbon neutrality goal by 2050, these findings emphasize the importance of boosting clean energy development-related investments, increasing clean electricity output, greening economic activities, reducing the trade of unclean commodities, adopting environmentally sustainable urbanization policies, and facilitating the influx of clean foreign direct investments within the Japanese economy.


Subject(s)
Carbon Dioxide , Renewable Energy , Commerce , Economic Development , Internationality , Investments
14.
Saudi Dent J ; 33(7): 753-760, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34803330

ABSTRACT

PURPOSE: The objective of this study was to explore the ambience of professionalism related to academic integrity among undergraduate dental students. METHODOLOGY: "Dundee Polyprofessionalism Inventory I: Academic Integrity" was used to collect responses from first-year to fifth-year dental students of the College of Dentistry, King Saud University (Response rate = 78%). The participants' responses (for 34 professionalism lapses) were recorded by using the Dundee Polyprofessionalism Inventory. Statistical analysis included descriptive statistics, Chi-square, and T-tests (P < 0.05). RESULTS: The "Ignore" sanction was not opted for any of the 34 professionalism behaviors, and there was unanimous agreement between the participants in considering all 34 behavior statements to be "wrong". Male and female participants were found to opt for a similar sanction as the median for 16 statements (47%), whereas, for 18 statements (53%), their responses differed with a range of levels 0.5 to 1.5. Preclinical- and clinical-year student responses also showed similarities in their 11 statements (32.3%), and they did differ for 20 statements (58.8%). Interestingly, clinical year respondents were overall on the stricter side of recommending sanctions. CONCLUSIONS: For the majority of the dental students tested, there was a good understanding of the significance of some lapses of professionalism associated with academic integrity. Some of the disclosures in this study were substantially appreciable because none of the students selected "ignore" sanction for any of the survey statements. We found that using the Dundee Polyprofessionalism Inventory for learning and understanding academic professionalism among dental students is useful.

15.
PeerJ Comput Sci ; 7: e722, 2021.
Article in English | MEDLINE | ID: mdl-34805500

ABSTRACT

Fault prediction is a necessity to deliver high-quality software. The absence of training data and mechanism to labeling a cluster faulty or fault-free is a topic of concern in software fault prediction (SFP). Inheritance is an important feature of object-oriented development, and its metrics measure the complexity, depth, and breadth of software. In this paper, we aim to experimentally validate how much inheritance metrics are helpful to classify unlabeled data sets besides conceiving a novel mechanism to label a cluster as faulty or fault-free. We have collected ten public data sets that have inheritance and C&K metrics. Then, these base datasets are further split into two datasets labeled as C&K with inheritance and the C&K dataset for evaluation. K-means clustering is applied, Euclidean formula to compute distances and then label clusters through the average mechanism. Finally, TPR, Recall, Precision, F1 measures, and ROC are computed to measure performance which showed an adequate impact of inheritance metrics in SFP specifically classifying unlabeled datasets and correct classification of instances. The experiment also reveals that the average mechanism is suitable to label clusters in SFP. The quality assurance practitioners can benefit from the utilization of metrics associated with inheritance for labeling datasets and clusters.

16.
Work ; 70(4): 1187-1194, 2021.
Article in English | MEDLINE | ID: mdl-34842205

ABSTRACT

OBJECTIVE: The aim of this study was to investigate the prevalence of metabolic syndrome (MS) among dentists in Riyadh, Saudi Arabia. The study also explored the causes of occupational stress among the participating dentists. MATERIALS & METHODS: The participants included a conveniently selected sample of dentists (N = 126; Males = 65; Females = 61). The participants' anthropometric measurements/blood sample analysis were carried out and they completed a self-administered questionnaire. Data analysis included demographics, gender/age wise comparison using SPSS (p < 0.05). For the diagnosis of MS, updated criteria of the National Cholesterol Education Program was applied. RESULTS: Participants diagnosed with MS were 13 (10.3%), Males = 11(8.7%) and Females = 2(1.5%). Physical activity of 6 (15.8%) with MS was only 0-2 hours/week. 9 (14.5%) participants with MS declared positive family history for MS. The average systolic (117.55±11.33) and diastolic blood pressure (71.9±9.34) of the participants was found to be normal with no gender wise statistical difference. No gender wise statistical differences (p > 0.05) were observed for cholesterol, triglycerides and HDL. However, significant difference (p = 0.00) was found for the fasting glucose level (Males = 5.69±1.49; Females = 4.94±0.42). Overall mean scoring (3.00±1.11) for the stress showed that the participants fall into the average/moderate level of stress category (Males = 3.16±1.02; Females = 2.83±1.08). Almost two third (68.26%) of the participant's responded that they were under some kind of stress. CONCLUSIONS: MS was found to be less frequent among the dentists working in the city of Riyadh. Overall, the dentists were under moderate level of occupational stress, with male dentists being more prone to work related stress.


Subject(s)
Metabolic Syndrome , Occupational Stress , Dentists , Female , Humans , Male , Metabolic Syndrome/epidemiology , Metabolic Syndrome/etiology , Occupational Stress/complications , Occupational Stress/epidemiology , Prevalence , Risk Factors
17.
J Neurodev Disord ; 13(1): 47, 2021 10 13.
Article in English | MEDLINE | ID: mdl-34645383

ABSTRACT

BACKGROUND: Individuals with Fragile X syndrome (FXS) and autism spectrum disorder (ASD) exhibit an array of symptoms, including sociability deficits, increased anxiety, hyperactivity, and sensory hyperexcitability. It is unclear how endocannabinoid (eCB) modulation can be targeted to alleviate neurophysiological abnormalities in FXS as behavioral research reveals benefits to inhibiting cannabinoid (CB) receptor activation and increasing endocannabinoid ligand levels. Here, we hypothesize that enhancement of 2-arachidonoyl-sn-glycerol (2-AG) in Fragile X mental retardation 1 gene knock-out (Fmr1 KO) mice may reduce cortical hyperexcitability and behavioral abnormalities observed in FXS. METHODS: To test whether an increase in 2-AG levels normalized cortical responses in a mouse model of FXS, animals were subjected to electroencephalography (EEG) recording and behavioral assessment following treatment with JZL-184, an irreversible inhibitor of monoacylglycerol lipase (MAGL). Assessment of 2-AG was performed using lipidomic analysis in conjunction with various doses and time points post-administration of JZL-184. Baseline electrocortical activity and evoked responses to sound stimuli were measured using a 30-channel multielectrode array (MEA) in adult male mice before, 4 h, and 1 day post-intraperitoneal injection of JZL-184 or vehicle. Behavior assessment was done using the open field and elevated plus maze 4 h post-treatment. RESULTS: Lipidomic analysis showed that 8 mg/kg JZL-184 significantly increased the levels of 2-AG in the auditory cortex of both Fmr1 KO and WT mice 4 h post-treatment compared to vehicle controls. EEG recordings revealed a reduction in the abnormally enhanced baseline gamma-band power in Fmr1 KO mice and significantly improved evoked synchronization to auditory stimuli in the gamma-band range post-JZL-184 treatment. JZL-184 treatment also ameliorated anxiety-like and hyperactivity phenotypes in Fmr1 KO mice. CONCLUSIONS: Overall, these results indicate that increasing 2-AG levels may serve as a potential therapeutic approach to normalize cortical responses and improve behavioral outcomes in FXS and possibly other ASDs.


Subject(s)
Autism Spectrum Disorder , Fragile X Mental Retardation Protein , Animals , Endocannabinoids , Fragile X Mental Retardation Protein/genetics , Glycerol , Male , Mice , Mice, Knockout
18.
Polymers (Basel) ; 13(20)2021 Oct 16.
Article in English | MEDLINE | ID: mdl-34685335

ABSTRACT

The aim is to compare the use of Cyanoacrylate adhesives (CAA) to the conventional suturing technique in terms of free gingival grafts (FGG) stability and healing in lower anterior and premolar regions. A split mouth design was initiated on 22 participants. Each side (from 2nd premolar to central incisor) was randomized to either the control or test groups. In the control group, sutures were used to stabilize the FGG, while, in the test group, the FGG was stabilized with butyl-cyanoacrylate. Full-periodontal clinical parameters were employed to assess the periodontal health. FGG-related parameters assessed included the keratinized tissue width (KTW), gingival tissue thickness (GTT), FGG shrinkage% and pain using the VAS score. No significant differences in the mean values of the KTW nor FGG shrinkage% across six time points (p < 0.05) were observed, whereas highly significant differences in the mean values of GTT across six time points (F = 3.32; p = 0.008) were observed. The use of CAA in FGG stability and healing is comparable to conventional suturing for soft tissue grafts in terms of success outcomes. With its cost effectiveness, lesser time consumption, post-operative pain and comparable graft stability and dimensions, the use of CAA may be a promising alternative for conventional and microsurgical techniques for the stabilization of FGG in the oral cavity.

19.
Polymers (Basel) ; 13(18)2021 Sep 13.
Article in English | MEDLINE | ID: mdl-34577984

ABSTRACT

Optimal bond strength between the prefabricated post/dowel to the surrounding dentin is essential. The present study aimed to analyze and compare the effect of three different cement film thicknesses on the pull-out bond strength of three different prefabricated post systems. Extracted natural teeth (N = 90) with similar root dimensions were acquired. Teeth were mounted in resin blocks, endodontically treated, sectioned at cemento-enamel junction, divided into three groups (A: Parapost Fiber Lux plus; B: 3M ESPE Relyx fiber post; and C: Parapost XP), and stored. Uniform post spaces were prepared for the groups (A and C: Length = 8 mm, Width = 1.5 mm; B: Length = 8 mm, Width = 1.6 mm). Each group (N = 30) was further subdivided into three subgroups (n = 10) based on the size (4, 5, and 6) of the post and cemented with resin cement (MultiLink-N, Ivoclar Vivadent). After thermocycling, the specimens were subjected to a pull-out test using a universal testing machine, and tensile force was recorded (MPa). Digital microscopic evaluations were performed for modes of failure. ANOVA and Tukey-HSD tests were used for statistics. Significant differences were observed for each tested material (p = 0.000). The lowest and highest bond strength values were recorded for Group C (Titanium post) and Group A (000), respectively. Multiple comparisons showed significance (p < 0.05) among all the groups, except for space 1 and space 2 (p = 0.316) for Group A. Most of the failures occurred within the cement-dentin and post-cement interface (Adhesive failures, 73.5%). An increase in the luting cement film thickness results in the decrease in pull-out bond strength of prefabricated posts luted with resin cement, irrespective of the type/material/shape of the post. The serrated fiber posts showed the highest pull-out bond strength compared to the smooth surfaced fiber posts or serrated metal posts. Increased pull-out bond strengths were observed when appropriate post space was created with the same sized drill as the post size.

20.
Materials (Basel) ; 14(17)2021 Aug 26.
Article in English | MEDLINE | ID: mdl-34500928

ABSTRACT

BACKGROUND: The purpose was to compare the fracture resistance and the mode of failure of different contemporary restorative materials to restore implant supported, cement-retained mandibular molars. METHODS: Two 5 × 10 mm titanium dental implants were mounted in resin blocks and prefabricated titanium and zirconia abutments were connected to each implant. Each implant received forty crowns resembling mandibular first molars. The specimens were divided into four groups (n = 10/group) for each abutment according to the type of material; Group A: porcelain fused to metal crowns; Group B: monolithic zirconia crowns; Group C: zirconia coping with ceramic veneer; Group D: all ceramic lithium disilicate crowns. Specimens were cemented to the abutments, mounted into a universal testing machine, and vertical static load was applied at a speed of 1 mm/min. The test stopped at signs of visual/audible fracture/chipping. Fracture resistance values were analyzed using ANOVA and Tukey's tests (α ≤ 0.05). The modes of failure were visually observed. RESULTS: A statistically significant difference (p < 0.001) of the fracture resistance values among tested groups was found. The group that showed the highest fracture resistance was Group A for both the titanium and the zirconia abutments (3.029 + 0.248 and 2.59 ± 0.39, respectively) while Group D for both abutments (1.134 + 0.289 and 1.68 ± 0.13) exhibited the least resistance. CONCLUSIONS: Fracture resistance and fracture mode varied depending on type of restorative material. For both titanium and zirconia abutments, porcelain fused to metal showed the highest fracture resistance values followed by monolithic zirconia.

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