حسين علي محمد حسين ديوان

Background: Dimensional precision of casts is essential for the quality of fixed prosthesis therapy, with the impression technique being a crucial component affecting this precision. This in vitro study is to evaluate the dimensional precision of casts generated from four varieties of impression materials. Materials and Methods: Utilizing 20 specimens, four types of impression materials were fabricated and subsequently classified into four groups: condensation silicone impression material group (heavy and light body), condensation silicone impression material group (light body only), addition silicone impression material group (heavy and light body), and alginate impression material group. Dimensional stability was evaluated by acquiring imprints of an acrylic mold with three supports that replicate a slightly edentulous arch, which were then filled with stone. The stability was assessed by shooting photos with a Canon digital macro-lens camera, thereafter measuring the distances between the three posts using AutoCAD software (three lines were measured). Results: This study evaluated the dimensional precision of four frequently utilized impression materials in comparison to the primary standard. Dimensional accuracy was evaluated along three measurement lines, revealing substantial deviations from the standard for all materials (p <0:05). Among the investigated materials, addition silicone light & heavy body displayed the highest values (mean perimeter of 155.024mm), which was closest to the control (perimeter of 163.405mm), indicating minimal dimen sional changes and exceptional dimensional stability. Conversely, Condensation silicone light & heavy body showed least values (146.06mm) suggesting the least dimensional accuracy compared to the other three impression materials. Alginate and Conden sation silicone light body showed comparable results when compared with each other (p >0:05) and were statistically better than Condensation silicone light & heavy and lower than addition silicone light & heavy. These findings highlight the significance of material selection for attaining accurate mold dimensions in clinical applications. Conclusion: In summary Although the digital technique may be more dependable and less complicated way to evaluate the qualities of impression materials, addition silicone heavy and light body demonstrated superior dimensional accuracy when compared with the other three impression materials. In contrast, among the four impression materials tested, condensation silicone heavy & light body had the largest dimensional shifts, indicating the lowest degree of dimensional accuracy. Keywords: AutoCAD software; dimensional stability; impression materials

Objec>ves: The quality of removable dentures (acrylic par8al and complete) significantly affects pa8ents’ quality of life, encompassing aspects such as aesthe8cs, func8on and the psychological well-being of individuals by restoring their smile. This study aimed to evaluate pa8ents’ sa8sfac8on with aesthe8cs, support, func8on, and comfort of acrylic removable par8al and complete dentures and their acceptance of the procedure. Materials and Methods: A total of 146 randomly selected par8ally and completely edentulous pa8ents (106 males and 40 females) with ages 30 years or more were included in this study. All par8cipa8ng pa8ents (120 par8ally, 23 completely edentulous and 3 pa8ents having one completely edentulous arch and another one is par8ally edentulous) were informed about the objec8ves of the study to get their acceptance in terms of esthe8c, func8on, reten8on, comfort and some other maJers by answering some ques8ons (a ques8onnaire consists of 17 mul8ple choice ques8ons, using Likert-type scale). Results: There was an acceptable level of pa8ent's sa8sfac8on with their constructed removable dentures, but they were more sa8sfied with their removable par8al denture in comparison to their complete one regarding the reten8on of the upper denture (p=0.007), chewing ability (p=0.025), speech (p=0.005) and comfort (p=0.003). Lower denture reten8on (p=0.062), aesthe8c pa8ent's appearance, (p=0.122), geQng ulcers aRer wearing the denture (p=0.125) and difficul8es during denture construc8on visits (p=0.838) did not show the same differences. Most pa8ents (68.49%) had been wearing dentures for more than a year. Conclusions: This study found generally posi8ve pa8ent experiences with both removable par8al and complete dentures, with higher sa8sfac8on observed among those with par8al dentures, par8cularly regarding reten8on, chewing, speech, and comfort. These findings highlight the benefits of preserving natural teeth and the importance of individualized care, especially during the ini8al adjustment period, to op8mize long-term denture success. Keywords: Dimensional Stability; Complete Dentures; Measuring Tools; Dimensional Accuracy; Micrometer Microscope.

Background: The objective of this research was to explore how the addition of boron nitride (BN) nanoparticles in the concentrations of 1% and 1.5% w/w affect the impact strength and surface roughness of heat-cured poly methyl methacrylate resin (PMMA). Methods: Sixty specimens were made from heat-cured acrylic resin and then divided into control, 1%, and 1.5% w/w BN groups. The impact strength and surface roughness were investigated. One-way ANOVA and Tukey’s post hoc test were used for data analysis. Results: Statistically significant difference is found among the three study groups regarding impact strength (P=0.011) and surface roughness test (P < 0.001). The post hoc test showed significant differences for all multiple comparisons for the surface roughness test (P < 0.001). Yet, multiple comparisons for the impact strength test revealed only a significant difference between the 1.5% BN and control groups (P= 0.005). Conclusion: The addition of boron BN into PMMA improves impact strength with 1.5% concentration; while adversely increase the surface roughness