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Mahrous AA, Liang L, Balaguer JM, Ho JC, Hari K, Grigsby EM, Karapetyan V, Damiani A, Fields DP, Gonzalez-Martinez JA, Gerszten PC, Bennett DJ, Heckman CJ, Pirondini E, Capogrosso M. GABA Increases Sensory Transmission In Monkeys. bioRxiv 2023:2023.12.28.573467. [PMID: 38234767 PMCID: PMC10793394 DOI: 10.1101/2023.12.28.573467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Sensory input flow is central to voluntary movements. For almost a century, GABA was believed to modulate this flow by inhibiting sensory axons in the spinal cord to sculpt neural inputs into skilled motor output. Instead, here we show that GABA can also facilitate sensory transmission in monkeys and consequently increase spinal and cortical neural responses to sensory inputs challenging our understanding of generation and perception of movement.
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Fouda SM, Ellakany P, Gad MM, Bahgat HA, Ayad NM, Ateeq IS, Dehailan LA, Mahrous AA. Fracture Strength of Composite Rest Seats: An In Vitro Comparative Study of Different Composite versus Amalgam Restorations. Materials (Basel) 2023; 16:4830. [PMID: 37445144 DOI: 10.3390/ma16134830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/27/2023] [Accepted: 07/03/2023] [Indexed: 07/15/2023]
Abstract
Occlusal rest provides support for removable partial dentures (RPD). Rest seats are ideally prepared in enamel, but the abutment teeth might be restored or need restorations. This study compared the fracture strength of abutments restored with composite to amalgam restorations after rest seat preparation. Disto-occlusal cavities were prepared in 30 extracted human maxillary premolars. The specimens were allocated in three groups (n = 10) based on the type of restoration. All the specimens were exposed to thermomechanical aging followed by cycling loading. Fracture strength was tested using a universal testing machine, and then, the fracture mode was recorded. The data were analyzed using Kruskal-Wallis test with a significance level set at 0.05. The fracture mode was recorded as catastrophic or non-catastrophic. The fracture strength between all tested groups showed no significant difference. The highest and lowest fracture strength were recorded on amalgam and Tetric N-Ceram groups, respectively. Composite Tetric N-Ceram showed equal distribution of fracture sites on the restorative materials and teeth, it also displayed the highest number of non-catastrophic fractures unlike other groups where the fracture occurred more within the restorations. The fracture strength of composite was comparable to that of amalgam restorations with prepared rest seats.
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Affiliation(s)
- Shaimaa M Fouda
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia
| | - Passent Ellakany
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia
| | - Mohammed M Gad
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia
| | - Hala A Bahgat
- Department of Removable Prosthodontics, College of Dentistry, Al-Ahram Canadian University, 6th of October 3221405, Egypt
| | - Neveen M Ayad
- Department of Restorative Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia
| | - Ijlal Shahrukh Ateeq
- Biomedical Engineering Department, College of Engineering, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia
| | - Laila Al Dehailan
- Department of Restorative Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia
| | - Amr A Mahrous
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia
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Ellakany P, Abualsaud R, Gad MM, Atteya S, El Meligy OA, Qutub OA, Mahrous AA. Knowledge of Saudi dental students and interns towards luting cements and their applications in fixed prosthodontics. BMC Oral Health 2023; 23:337. [PMID: 37254115 DOI: 10.1186/s12903-023-03054-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 05/17/2023] [Indexed: 06/01/2023] Open
Abstract
BACKGROUND Enhancement of students' knowledge is essential in improving their clinical skills and performance. Thus, the curriculum should be prepared to achieve a better outcome. The current study aimed to determine the dental students' and interns' basic knowledge towards dental luting cements and their application in dental practice to improve the theoretical and clinical training sections. MATERIALS AND METHODS A cross-sectional study was conducted among dental students and interns at three Colleges of Dentistry in the Kingdom of Saudi Arabia between September 2019-June 2020. An online questionnaire was used which included demographic data, questions about luting cement usage, cementation techniques, and commonly used cements in dental clinics. Descriptive analysis and chi-square test were used to show the association between level of dental education and the use of dental cements using SPSS software. The significance level was set at 5%. RESULTS The total respondents were 626 dental students/interns of whom 78.8% were undergraduate dental students. Participants who reported undergraduate studies as the source of information were 79.7%. The type of restoration was the main factor in luting cement selection (62.6%). Concerning the isolation technique in cementing laminate veneers, 49.7% used dri-angles, cotton rolls and saliva ejectors. Dual-cure resin cement was the most common cement used in all the mentioned restorations except in pressed porcelain laminate veneers and cement-retained implant-supported restorations. CONCLUSIONS Students' knowledge and practice in managing dental implants and porcelain laminate veneers need to be improved. The selection of a luting agent for a given restoration by students and interns was based on the basic knowledge, available cement, and the type of restoration. Awareness towards the management of short prepared teeth and custom-made cast posts and cores is also limited.
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Affiliation(s)
- Passent Ellakany
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Reem Abualsaud
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Mohammed M Gad
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Sara Atteya
- Department of Pediatric Dentistry and Dental Public Health, Faculty of Dentistry, Alexandria University, Champollion St, Azarita, 21527, Alexandria, Egypt.
| | - Omar A El Meligy
- Department of Pediatric Dentistry and Dental Public Health, Faculty of Dentistry, Alexandria University, Champollion St, Azarita, 21527, Alexandria, Egypt
- Department of Pediatric Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Osama A Qutub
- Department of Oral and Maxillofacial Prosthodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Amr A Mahrous
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
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Mahrous AA, Alhammad A, Alqahtani F, Aljar Y, Alkadi A, Taymour N, Alotaibi A, Akhtar S, Gad MM. The Toothbrushing Effects on Surface Properties and Color Stability of CAD/CAM and Pressable Ceramic Fixed Restorations-An In Vitro Study. Materials (Basel) 2023; 16:2950. [PMID: 37109785 PMCID: PMC10142931 DOI: 10.3390/ma16082950] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/04/2023] [Accepted: 04/05/2023] [Indexed: 06/19/2023]
Abstract
Pressable ceramic restorations have been introduced and investigated, and found comparable to CAD/CAM ceramic in terms of mechanical properties; however, the effect of toothbrushing on the pressable ceramic has not been thoroughly investigated. The objective of the current study was to assess the effect of artificial toothbrushing simulation on the surface roughness, microhardness, and color stability of different ceramic materials. Three lithium disilicate-based ceramics (IPS Emax CAD [EC], IPS Emax Press [EP]; (Ivoclar Vivadent AG), and LiSi Press [LP] (GC Corp, Tokyo, Japan)) were examined. For each ceramic material, eight bar-shaped specimens were prepared and subjected to 10,000 brushing cycles. Surface roughness, microhardness, and color stability (∆E) were measured before and after brushing. Scanning electron microscopy (SEM) was used for surface profile analysis. The results were analyzed using one-way ANOVA, Tukey's post hoc test, and paired sample t-test α = 0.05. The findings revealed a non-significant decrease in the surface roughness of EC, EP, and LP groups (p > 0.05), and both LP and EP have the lowest surface roughness values (0.64 ± 0.13, 0.64 ± 0.08 µm) after brushing, respectively. Toothbrushing showed a decrease in the microhardness of the three groups: EC and LP, p < 0.001; EP, p = 0.012). EP showed the lowest hardness value after brushing (862.45 ± 273.83). No significant changes (∆E) were observed in all groups (p > 0.05); however, the EC group was found to be considerably affected by color changes, in comparison to the EC and LP groups. Toothbrushing had no effect on surface roughness and color stability of all tested materials, but it decreased the microhardness. Material type, surface treatments, and glazing of ceramic materials contributed to the surface changes in the ceramic materials, necessitating further investigations in terms of the toothbrushing effect with different glazing as variables.
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Affiliation(s)
- Amr A. Mahrous
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia; (A.A.M.); (N.T.); (A.A.)
| | - Abdullah Alhammad
- College of Dentistry, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia; (A.A.); (F.A.); (Y.A.)
| | - Faisal Alqahtani
- College of Dentistry, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia; (A.A.); (F.A.); (Y.A.)
| | - Yousif Aljar
- College of Dentistry, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia; (A.A.); (F.A.); (Y.A.)
| | - Ahmed Alkadi
- College of Dentistry, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia; (A.A.); (F.A.); (Y.A.)
| | - Noha Taymour
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia; (A.A.M.); (N.T.); (A.A.)
| | - Abdulkareem Alotaibi
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia; (A.A.M.); (N.T.); (A.A.)
| | - Sultan Akhtar
- Department of Biophysics, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia;
| | - Mohammed M. Gad
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia; (A.A.M.); (N.T.); (A.A.)
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Ellakany P, Fouda SM, Mahrous AA, AlGhamdi MA, Aly NM. Influence of CAD/CAM Milling and 3D-Printing Fabrication Methods on the Mechanical Properties of 3-Unit Interim Fixed Dental Prosthesis after Thermo-Mechanical Aging Process. Polymers (Basel) 2022; 14:polym14194103. [PMID: 36236050 PMCID: PMC9572976 DOI: 10.3390/polym14194103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/16/2022] [Accepted: 09/18/2022] [Indexed: 11/20/2022] Open
Abstract
This study assessed the influence of CAD/CAM milling and 3D-printing fabrication methods on mechanical properties of 3-unit interim fixed dental prosthesis (IFDPs) after thermo-mechanical aging. Forty 3-unit IFDPs were fabricated on a mandibular right second premolar and second molar of a typodont cast. Samples were fabricated from the following materials; auto-polymerized polymethyl methacrylate (conventional resin), CAD/CAM PMMA (milled resin) and two different CAD/CAM 3D-printed composite resins; digital light processing Asiga (DLP AS) and stereolithography NextDent (SLA ND). Mechanical properties were compared between the studied materials using Kruskal−Wallis test, followed by multiple pairwise comparisons using Bonferroni adjusted significance. There was a significant difference in flexural strength and microhardness between the studied materials (p < 0.001), with the highest mean ± SD reported in the milled IFDPs (174.42 ± 3.39, 27.13 ± 0.52), and the lowest in the conventional IFDPs (98.02 ± 6.1, 15.77 ± 0.32). Flexural strengths differed significantly between the conventional IFDPs and all materials except DLP AS. The highest elastic modulus was recorded in the milled group, and the lowest in the SLA ND group (p = 0.02). In conclusion, superior flexural strength, elastic modulus, and hardness were reported for milled IFDPs. SLA ND printed IFDPs showed comparable mechanical properties to milled ones except for the elastic modulus.
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Affiliation(s)
- Passent Ellakany
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 32210, Saudi Arabia
- Correspondence: ; Tel.: +966-547812107
| | - Shaimaa M. Fouda
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 32210, Saudi Arabia
| | - Amr A. Mahrous
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 32210, Saudi Arabia
| | - Maram A. AlGhamdi
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 32210, Saudi Arabia
| | - Nourhan M. Aly
- Department of Pediatric Dentistry and Dental Public Health, Faculty of Dentistry, Alexandria University, Alexandria 21527, Egypt
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Mahrous AA, Ellakany P, Abualsaud R, Al-Thobity AM, Akhtar S, Siddiqui IA, Gad MM. Comparative Study of the Effectiveness of Laboratory-Formulated Polishing Pastes for Two CAD/CAM Ceramic Restorative Materials. J Prosthodont 2021; 31:529-536. [PMID: 34693606 DOI: 10.1111/jopr.13444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/17/2021] [Indexed: 11/27/2022] Open
Abstract
PURPOSE To evaluate the effect of different polishing pastes with different particle sizes on the surface finish of two different CAD/CAM ceramics. MATERIALS AND METHODS A total of 128 specimens were prepared of two CAD/CAM ceramics: lithium disilicate (12.4 × 14.5 × 2 mm) and monolithic zirconia (17.5 × 12.5 × 2.5 mm). They were divided randomly into 8 groups according to surface treatment (n = 8). Group 1 (control) was left as received after crystallization or sintering with no further surface treatment; Group 2 (glazed); Group 3 (positive control), where specimens were polished using standardized surface treatment (medium grit silicon carbide discs, rubber cup and pumice slurry, then rubber cup and toothpaste). For groups 4 to 8, in addition to silicon carbide and pumice slurry polishing, specimens were further polished using a diamond paste (DP), and polishing pastes of microzirconia (MZ), nanosilica (NS), nanodiamond (ND), and nanozirconia (NZ), respectively. Surface roughness (Ra ) was measured using noncontact profilometer. The mean values were compared using ANOVA and Post Hoc Tukey's test (α = 0.05). Specimens' surfaces were studied using a scanning electron microscope (SEM). RESULTS Positive control group and MZ exhibited significant Ra of lithium disilicate compared to control (p ˂ 0.001), glazed (p = 0.001), DPs (p = 0.002), NS (p ˂ 0.001), ND (p ˂ 0.001), and NZ (p = 0.002). In the case of zirconia, positive control showed a significantly higher Ra compared to all other groups (p ˂ 0.001). No statistical difference was found between all other polishing techniques (positive control, glazed, DPs, NS, ND, MZ, and NZ) (p > 0.05). CONCLUSION Polishing with ND, NZ, and NS lab-formulated pastes produced surfaces with comparable smoothness to control and glazed specimens for lithium disilicate and zirconia ceramic materials.
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Affiliation(s)
- Amr A Mahrous
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Passent Ellakany
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Reem Abualsaud
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Ahmad M Al-Thobity
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Sultan Akhtar
- Department of Biophysics, Institute for Research and Medical Consultations, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Intisar A Siddiqui
- Department of Dental Education, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Mohammed M Gad
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
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Ellakany P, Tantawi ME, Mahrous AA, Al-Harbi F. Evaluation of the Accuracy of Digital Impressions Obtained from Intraoral and Extraoral Dental Scanners with Different CAD/CAM Scanning Technologies: An In Vitro Study. J Prosthodont 2021; 31:314-319. [PMID: 34085355 DOI: 10.1111/jopr.13400] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/01/2021] [Indexed: 11/28/2022] Open
Abstract
PURPOSE To compare the accuracy of intraoral and extraoral scanners (IOSs and EOSs) with different scanning technologies. MATERIAL AND METHODS A phantom cast was used to simulate the patient's mouth. Polyether impression was made of the phantom cast and poured to fabricate stone casts. The stone casts were scanned by two IOSs (3shape Trios 3, 3S and Dental Wings, DW) and two EOSs (S600 Arti Zirkonzahn, ZK and Ceramill map 600 Amann Girrbach, AG) to obtain digital casts. Reference teeth (canines, premolar, and molars) dimensions were measured on the digital casts by Geomagic software and compared to measurements of the stone cast done by stereomicroscope. The dimensions were occluso-cervical mesio-distal, and bucco-lingual and their average was calculated. Differences between digital and stereoscopic measurements were assessed using paired t-test. Discrepancies between these measurements were calculated as differences and were compared among the four scanners using ANOVA. RESULTS The differences among the discrepancies of the four scanners were not significant overall (p = 0.969), in premolars (p = 0.932) or molars (p = 0.069) but significant in canines (p = 0.025). The discrepancies of the EOSs were ≤0.01 mm in canines and molars. DW had the greatest discrepancy in canines and molars. CONCLUSIONS The IOSs and EOSs had similar accuracy except in canines where EOSs performed better. The accuracy of scanning is affected by the smoothness and regularity of the teeth surfaces as in case of the canine.
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Affiliation(s)
- Passent Ellakany
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Maha El Tantawi
- Department of Pediatric Dentistry and Dental Public Health, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
| | - Amr A Mahrous
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Fahad Al-Harbi
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
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Gad MM, Abualsaud R, Alqarawi FK, Emam ANM, Khan SQ, Akhtar S, Mahrous AA, Al-Harbi FA. Translucency of nanoparticle-reinforced PMMA denture base material: An in-vitro comparative study. Dent Mater J 2021; 40:972-978. [PMID: 33883327 DOI: 10.4012/dmj.2020-296] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The aim of this study was to assess the translucency of denture base acrylic resin reinforced with zirconium dioxide (ZrO2NPs), silicon dioxide (SiO2NPs), and diamond (DNPs) nanoparticles. A total of 130 heat-polymerized acrylic discs (15×2.5 mm) were fabricated conventionally and divided into control and experimental groups according to nanoparticle type and concentration (0.5, 1, 1.5, and 2.5 wt%). Unmodified acrylic resin specimens served as control. All specimens were thermocycled (5,000 cycles). Translucency was measured using a spectrophotometer. ANOVA and post-hoc Turkeys' test were used for data analysis at α=0.05. The translucency of modified PMMA was significantly lower than control (p<0.05) except 0.5% ZrO2NPs and SiO2NPs (p>0.05) which exhibited the highest translucency values among modified groups. As the NPs concentration increased, the translucency decreased and the lowest value was seen with 2.5% DNPs (1.18±0.10). The addition of ZrO2NPs, SiO2NPs, and DNPs into denture base resin decreased the translucency.
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Affiliation(s)
- Mohammed M Gad
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University
| | - Reem Abualsaud
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University
| | - Firas K Alqarawi
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University
| | - Abdel-Naser M Emam
- Department of Removable Prosthodontics, Faculty of Dental Medicine, Al-Azhar University
| | - Soban Q Khan
- Department of Dental Education, College of Dentistry, Imam Abdulrahman Bin Faisal University
| | - Sultan Akhtar
- Department of Biophysics, Institute for Research and Medical Consultations, Imam Abdulrahman Bin Faisal University
| | - Amr A Mahrous
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University
| | - Fahad A Al-Harbi
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University
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Ellakany P, Mahrous AA, Al Eraky DM, Albarrak A, AlJindan R, Fouda SM. Evaluation of Bacterial Leakage in Platform-Switching Dental Implant with Morse Taper Connection Under Thermocycling and Loading Effects: In Vitro Study. Int J Oral Maxillofac Implants 2021; 36:68-74. [PMID: 33600525 DOI: 10.11607/jomi.8424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE The aim of this study was to test in vitro the bacterial microleakage at the Morse taper implant-abutment connection with switched platform subjected to functional load and thermocycling. MATERIALS AND METHODS A total of 48 Morse taper implant-abutment connections with switched platforms (12 implants per group) were used. The abutments were attached to implants and presented in four groups: group 1, control; group 2, subjected to thermocycling; group 3, subjected to cyclic compressive loading; and group 4, subjected to thermocycling and cyclic compressive loading. All groups were then inoculated in Eppendorf tubes including three types of bacterial suspensions: Enterococcus faecalis, Staphylococcus aureus, and Pseudomonas aeruginosa for 7 and 14 days to detect possibility of bacterial infiltration from outside to the internal chamber of the implant. RESULTS Implants not exposed to cyclic loading and thermocycling (group 1) and those exposed to thermocycling (group 2) exhibited no infiltration of E faecalis, S aureus, and P aeruginosa from outside to the inner chamber of the implant, while infiltration of P aeruginosa was only observed in implants subjected to cyclic loading only (group 3) and those subjected to cyclic loading in conjunction with thermocycling (group 4). CONCLUSION Microbial leakage at the implant-abutment connection is influenced by the applied load alone and in combination with thermocycling; however, E faecalis and S aureus did not leak at the implant-abutment connection even under these circumstances. Only P aeruginosa infiltrated inside the implant-abutment connection, which might be caused by its swarming motility.
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Mahrous AA, El-Tahan AAH, Hafez YH, El-Shora MA, Olafadehan OA, Hamdon H. Effect of date palm (Phoenix dactylifera L.) leaves on productive performance of growing lambs. Trop Anim Health Prod 2021; 53:72. [PMID: 33400015 PMCID: PMC7785545 DOI: 10.1007/s11250-020-02493-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 12/03/2020] [Indexed: 12/03/2022]
Abstract
Eighteen 4-month-old lambs, with a mean live weight (LW) of 19.47 ± 0.20 kg, were used to evaluate the nutritive value of date palm leaves (DPL) ensiled with different additives in a completely randomized design. Lambs were stratified into three groups of 6 lambs each and fed a control diet comprising 60% concentrate feed mixture (CFM) and 40% DPL silage (T1). In other treatments, the DPL silage (DPLS) of the control treatment was replaced with EM1 additive-treated DPLS (T2) or El-Mofeed additive-treated DPLS (T3). Apparent digestibility, total digestible nutrient, digestible crude protein, dry matter intake, daily weight gain (DWG), price of DWG, daily profit, and economics of feed efficiency were higher (P < 0.05) for the additives-treated DPLS relative to the control, with T2 enhancing these parameters compared with T3. With exception of ruminal pH, which was reduced, concentrations of ruminal NH3-N and total volatile fatty acids (VFA) increased 4 h post feeding. However, ruminal NH3-N and total VFA were greater (P < 0.05) for the additives-treated DPLS, with T2 producing higher values than T3. Ruminal pH and feed cost/kg LW gain were lower for T2 relative to other treatments. Blood constituents were within the normal ranges for lambs, though slightly altered by treatments. Whereas serum total protein, albumin, and globulin were affected (P < 0.05) in this rank order, T1 < T3 < T2, other serum parameters were not affected. Relative feed cost and relative daily profit were lower and higher respectively for T2 than for T3. It is concluded that additives-treated DPLS is nutritionally superior to untreated DPLS as a roughage source in total mixed rations fed to growing lambs. However, for improved performance of the lambs and economic benefits, EM1-treated DPLS is recommended.
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Affiliation(s)
- A A Mahrous
- Animal Production Research Institute, Agricultural Research Center, Dokki, Giza, Egypt
| | - A A H El-Tahan
- Animal Production Research Institute, Agricultural Research Center, Dokki, Giza, Egypt
| | - Y H Hafez
- Animal Production Research Institute, Agricultural Research Center, Dokki, Giza, Egypt
| | - M A El-Shora
- Animal Production Research Institute, Agricultural Research Center, Dokki, Giza, Egypt
| | - O A Olafadehan
- Department of Animal Science, University of Abuja, Abuja, P.M.B. 117, Nigeria
| | - H Hamdon
- Department of Animal Production, Faculty of Agriculture, New Valley University, New Valley, Egypt.
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11
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Mahrous AA, Heckman CJ. It takes a circuit to develop a mature motoneuron. J Physiol 2020; 598:5301-5302. [PMID: 32969023 DOI: 10.1113/jp280707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 09/14/2020] [Indexed: 11/08/2022] Open
Affiliation(s)
- Amr A Mahrous
- Department of Physiology, Northwestern University, Chicago, IL, USA
| | - C J Heckman
- Department of Physiology, Northwestern University, Chicago, IL, USA.,Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, IL, USA.,Department of Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, IL, USA
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12
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Mahrous AA, Mousa MH, Elbasiouny SM. The Mechanistic Basis for Successful Spinal Cord Stimulation to Generate Steady Motor Outputs. Front Cell Neurosci 2019; 13:359. [PMID: 31456665 PMCID: PMC6698793 DOI: 10.3389/fncel.2019.00359] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 07/23/2019] [Indexed: 11/29/2022] Open
Abstract
Electrical stimulation of the spinal cord is a promising rehabilitation intervention to restore/augment motor function after spinal cord injury (SCI). Combining sensory feedback with stimulation of remaining motor circuits has been shown to be a prerequisite for the functional improvement of SCI patients. However, little is known about the cellular mechanisms potentially underlying this functional benefit in the injured spinal cord. Here, we combine computer simulations with an isolated whole-tissue adult mouse spinal cord preparation to examine synaptic, cellular, and system potentials measured from single motoneurons and ventral roots. The stimulation protocol included separate and combined activation of the sensory inputs (evoked by dorsal root stimulation) and motor inputs (evoked by stimulation of spinal cord tissue) at different frequencies, intensities, and neuromodulatory states. Our data show that, while sensory inputs exhibit short-term depression in response to a train of stimulation, motor inputs exhibit short-term facilitation. However, the concurrent activation of both inputs elicits a stronger and steadier motor output. This effect is enhanced by the application of pharmacological neuromodulators. Furthermore, sensorimotor excitatory postsynaptic potentials (EPSPs) summate sublinearly (i.e., their combination produces an excitatory potential smaller than the sum of the excitatory potentials they would individually produce). However, ventral root compound action potentials (CoAPs) summate supralinearly generating much higher outputs. Computer simulations revealed that the contrasting summation and disproportionality in plasticity between the excitatory postsynaptic potentials (EPSPs) and CoAPs result from the motoneuronal firing threshold acting as an amplitude-selective filter. Together, these results provide the mechanistic basis for the cellular processes contributing to the generation of steady motor outputs using spinal stimulation. This data has great potential to guide the design of more effective stimulation protocols in SCI patients.
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Affiliation(s)
- Amr A Mahrous
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, United States.,Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Mohamed H Mousa
- Department of Biomedical, Industrial, and Human Factors Engineering, College of Engineering and Computer Science, Wright State University, Dayton, OH, United States
| | - Sherif M Elbasiouny
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, United States.,Department of Biomedical, Industrial, and Human Factors Engineering, College of Engineering and Computer Science, Wright State University, Dayton, OH, United States
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Abstract
The spinal cord contains specialized groups of cells called pattern generators, which are capable of orchestrating rhythmic firing activity in an isolated preparation. Different patterns of activity could be generated in vitro including right-left alternating bursting and bursting in which both sides are synchronized. The cellular and network mechanisms that enable these behaviors are not fully understood. We have recently shown that Ca2+-activated K+ channels (SK channels) control the initiation and amplitude of synchronized bursting in the spinal cord. It is unclear, however, whether SK channels play a similar role in the alternating rhythmic pattern. In the current study, we used a spinal cord preparation from functionally mature mice capable of weight bearing and walking. The present results extend our previous work and show that SK channel inhibition initiates and modulates the amplitude of alternating bursting. We also show that addition of methoxamine, an α1-adrenergic agonist, to a cocktail of serotonin, dopamine, and NMDA evokes robust and consistent alternating bursting throughout the cord.
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Affiliation(s)
- Amr A Mahrous
- a Department of Neuroscience , Cell Biology, and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University , Dayton , Ohio , USA
| | - Sherif M Elbasiouny
- a Department of Neuroscience , Cell Biology, and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University , Dayton , Ohio , USA.,b Department of Biomedical , Industrial, and Human Factors Engineering, College of Engineering and Computer Science, Wright State University , Dayton , Ohio , USA
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14
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Mahrous AA, Elbasiouny SM. SK channel inhibition mediates the initiation and amplitude modulation of synchronized burst firing in the spinal cord. J Neurophysiol 2017; 118:161-175. [PMID: 28356481 DOI: 10.1152/jn.00929.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 03/06/2017] [Accepted: 03/25/2017] [Indexed: 11/22/2022] Open
Abstract
Burst firing in motoneurons represents the basis for generating meaningful movements. Neuromodulators and inhibitory receptor blocker cocktails have been used for years to induce burst firing in vitro; however, the ionic mechanisms in the motoneuron membrane that contribute to burst initiation and amplitude modulation are not fully understood. Small conductance Ca2+-activated potassium (SK) channels regulate excitatory inputs and firing output of motoneurons and interneurons and therefore, are a candidate for mediating bursting behavior. The present study examines the role of SK channels in the generation of synchronized bursting using an in vitro spinal cord preparation from adult mice. Our results show that SK channel inhibition is required for both initiation and amplitude modulation of burst firing. Specifically, administration of the synaptic inhibition blockers strychnine and picrotoxin amplified the spinal circuit excitatory drive but not enough to evoke bursting. However, when SK channels were inhibited using various approaches, the excitatory drive was further amplified, and synchronized bursting was always evoked. Furthermore, graded SK channel inhibition modulated the amplitude of the burst in a dose-dependent manner, which was reversed using SK channel activators. Importantly, modulation of neuronal excitability using multiple approaches failed to mimic the effects of SK modulators, suggesting a specific role for SK channel inhibition in generating bursting. Both NMDA (N-methyl-d-aspartate) and AMPA (α-amino-3-hydroxy-5-methylisoxazole-4-propionate) receptors were found to drive the synchronized bursts. The blocking of gap junctions did not disturb the burst synchrony. These results demonstrate a novel mechanistic role for SK channels in initiating and modulating burst firing of spinal motoneurons.NEW & NOTEWORTHY This study demonstrates that cholinergic inhibition or direct blockade of small conductance Ca2+-activated potassium (SK) channels facilitates burst firing in spinal motoneurons. The data provide a novel mechanistic explanation for synchronized bursting initiation and amplitude modulation through SK channel inhibition. Evidence also shows that synchronized bursting is driven by NMDA (N-methyl-d-aspartate) and AMPA (α-amino-3-hydroxy-5-methylisoxazole-4-propionate) receptors and that gap junctions do not mediate motoneuron synchronization in this behavior.
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Affiliation(s)
- Amr A Mahrous
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, Ohio; and
| | - Sherif M Elbasiouny
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, Ohio; and .,Department of Biomedical, Industrial, and Human Factors Engineering, College of Engineering and Computer Science, Wright State University, Dayton, Ohio
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15
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Al-Harbi FA, Ayad NM, Khan ZA, Mahrous AA, Morgano SM. In vitro shear bond strength of Y-TZP ceramics to different core materials with the use of three primer/resin cement systems. J Prosthet Dent 2016; 115:84-9. [PMID: 26412003 DOI: 10.1016/j.prosdent.2015.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 07/07/2015] [Accepted: 07/14/2015] [Indexed: 11/19/2022]
Affiliation(s)
- Fahad A Al-Harbi
- Associate Professor, Substitutive Dental Sciences Department, University of Dammam, Dammam, Saudi Arabia
| | - Neveen M Ayad
- Associate Professor, Restorative Dental Sciences Department, University of Dammam, Dammam, Saudi Arabia; and Assistant Professor, Dental Biomaterials Department, Mansoura University, Mansoura, Egypt
| | - Zahid A Khan
- Lecturer, Substitutive Dental Sciences Department, University of Dammam, Dammam, Saudi Arabia
| | - Amr A Mahrous
- Professor, Substitutive Dental Sciences Department, University of Dammam, Dammam, Saudi Arabia
| | - Steven M Morgano
- Professor, Rutgers School of Dental Medicine, Rutgers University, Newark, NJ.
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