Yasser Almhimeed - Academia.edu (original) (raw)
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Papers by Yasser Almhimeed
Zeitschrift für Medizinische Physik, 2020
Objective: To investigate the effect of two light-curing systems; quartz tungsten-halogen (QTH) a... more Objective: To investigate the effect of two light-curing systems; quartz tungsten-halogen (QTH) and light-emitting diode (LED), and irradiation time on interfacial gap formation of dental composite resin restorations bonded with an adhesive resin using optical coherence tomography (OCT). Materials and Methods: Forty cavities were prepared in extracted human molar teeth and divided into four groups (n = 10) based on the type of light curing system QTH (LITEX 680A) and LED (Demi Plus) and curing duration (10 s or 40 s). A single-step self-etching dental adhesive (Tetric ® N-Bond; Ivoclar Vivadent AG, Schaan, FL, Liechtenstein) was applied and polymerized with QTH for 10 s (QTH-10), or for 40 s (QTH-40). Similarly, the adhesive in LED-10 and LED-40 groups was polymerized with an LED for 10 s or 40 s, respectively. Then, all specimens were restored with Filtek TM Z350 XT flowable composite (3 M ESPE AG, St. Paul, MN, USA) and immersed in ammoniacal silver-nitrate contrasting solution. Cross-sectional images were recorded at every 250 m using cross-polarization OCT system (CP-OCT; IVS-300, Santec, Komaki, Aichi, Japan). Image analysis to quantify the percentage of gap at resin-dentin interface was performed using a custom plugin for ImageJ software. Results: Data analysis using one-way ANOVA showed a significant difference in mean gap percentage between the four test groups (p < 0.0001). Mean gap percentage values were 75.8%, 53.2%, 9.9% and 5.6%. The highest for LED-10 followed by LED-40 (p < 0.05). QTH-40 revealed a slightly better adaptation compared with QTH-10, but the difference between them was not significant (p < 0.05). Conclusion: CP-OCT with a contrast agent is a useful non-invasive imaging tool for dental composite resin materials. QTH showed better results than LED under the experimental conditions. When using an LED light-curing unit, prolonged irradiation improved interfacial adaptation of dental composite bonded with a self-etching adhesive.
International Journal Of Community Medicine And Public Health
Micro-endodontics has emerged as a critical component in endodontics, revolutionizing the managem... more Micro-endodontics has emerged as a critical component in endodontics, revolutionizing the management of complex root canal anatomy. It utilizes magnification devices, such as dental operating microscopes or loupes, to enhance visualization and identify intricate anatomical details. Micro-endodontics encompasses advanced techniques and technologies that are utilized alongside the principles of conventional endodontics. While both approaches share common goals of cleaning, disinfection, and obturation of the root canal system, micro-endodontics specifically focuses on managing complex root canal anatomy by utilizing specialized tools and techniques to enhance visualization, instrumentation, disinfection, and obturation. Ultrasonic instruments aid in negotiating challenging canal configurations and removing obstructions. Nickel-titanium rotary instruments offer flexibility and durability for efficient cleaning and shaping. Advanced irrigation techniques, such as ultrasonics and laser-a...
Zeitschrift für Medizinische Physik, 2020
Objective: To investigate the effect of two light-curing systems; quartz tungsten-halogen (QTH) a... more Objective: To investigate the effect of two light-curing systems; quartz tungsten-halogen (QTH) and light-emitting diode (LED), and irradiation time on interfacial gap formation of dental composite resin restorations bonded with an adhesive resin using optical coherence tomography (OCT). Materials and Methods: Forty cavities were prepared in extracted human molar teeth and divided into four groups (n = 10) based on the type of light curing system QTH (LITEX 680A) and LED (Demi Plus) and curing duration (10 s or 40 s). A single-step self-etching dental adhesive (Tetric ® N-Bond; Ivoclar Vivadent AG, Schaan, FL, Liechtenstein) was applied and polymerized with QTH for 10 s (QTH-10), or for 40 s (QTH-40). Similarly, the adhesive in LED-10 and LED-40 groups was polymerized with an LED for 10 s or 40 s, respectively. Then, all specimens were restored with Filtek TM Z350 XT flowable composite (3 M ESPE AG, St. Paul, MN, USA) and immersed in ammoniacal silver-nitrate contrasting solution. Cross-sectional images were recorded at every 250 m using cross-polarization OCT system (CP-OCT; IVS-300, Santec, Komaki, Aichi, Japan). Image analysis to quantify the percentage of gap at resin-dentin interface was performed using a custom plugin for ImageJ software. Results: Data analysis using one-way ANOVA showed a significant difference in mean gap percentage between the four test groups (p < 0.0001). Mean gap percentage values were 75.8%, 53.2%, 9.9% and 5.6%. The highest for LED-10 followed by LED-40 (p < 0.05). QTH-40 revealed a slightly better adaptation compared with QTH-10, but the difference between them was not significant (p < 0.05). Conclusion: CP-OCT with a contrast agent is a useful non-invasive imaging tool for dental composite resin materials. QTH showed better results than LED under the experimental conditions. When using an LED light-curing unit, prolonged irradiation improved interfacial adaptation of dental composite bonded with a self-etching adhesive.
International Journal Of Community Medicine And Public Health
Micro-endodontics has emerged as a critical component in endodontics, revolutionizing the managem... more Micro-endodontics has emerged as a critical component in endodontics, revolutionizing the management of complex root canal anatomy. It utilizes magnification devices, such as dental operating microscopes or loupes, to enhance visualization and identify intricate anatomical details. Micro-endodontics encompasses advanced techniques and technologies that are utilized alongside the principles of conventional endodontics. While both approaches share common goals of cleaning, disinfection, and obturation of the root canal system, micro-endodontics specifically focuses on managing complex root canal anatomy by utilizing specialized tools and techniques to enhance visualization, instrumentation, disinfection, and obturation. Ultrasonic instruments aid in negotiating challenging canal configurations and removing obstructions. Nickel-titanium rotary instruments offer flexibility and durability for efficient cleaning and shaping. Advanced irrigation techniques, such as ultrasonics and laser-a...