Antifungal and physical characteristics of modified denture base acrylic incorporated with silver nanoparticlesObjective: This study evaluated the antifungal and physical characteristics of denture base acrylic combined with silver nanoparticles. Materials and methods: Polymerized denture acrylic disc specimens containing 0 (control), 1.0, 5.0, 10.0, 20.0 and 30.0 wt% of silver nanoparticles were placed on separate culture plate dish and 100 ìL samples of yeast suspension of Candida albicans strain were inoculated on each specimens and incubated at 37°C, for 24 h. The antifungal effects were evaluated as a number of viable cells in retrieved fungal suspension. To characterize physical aspects, specimens were tested for elution of silver cation (Ag + ) at 24 h and 30th day, thermal analysis (TG/DTA), scanning electron microscope and energy dispersed X-ray analysis (SEM/EDX) and color stability. Results: Significant reduced CFU was exhibited at 20.0 and 30.0 wt% of silver nanoparticles incorporated (p < 0.01) and Ag + elution from specimens (maximum 0.356 ± 0.11 mg/L) contributed little to the antifungal activity considering MIC of Ag + in this study (3.0 mg/L). The successful synthesis of modified denture acrylic containing silver nanoparticles was accessed by TG/DTA and EDX analysis. Conclusion: The modified denture base acrylic combined with silver nanoparticles displayed antifungal properties and acted like latent antifungal material itself with low-releasing Ag + , however, the improvement of poor color stability was still required.

Three-dimensional (3D) printing technologies have been widely used to manufacture crowns and frameworks for fixed dental prostheses. This systematic review and meta-analysis aimed to assess the reliability of the marginal fit of 3D-printed cobalt-chromium-based fixed dental prostheses in comparison to conventional casting methods. Articles published until 25 June 2020, reporting the marginal fit of fixed prostheses fabricated with metal 3D printing, were searched using electronic literature databases. After the screening and quality assessment, 21 eligible peer-reviewed articles were selected. Meta-analysis revealed that the marginal gap of the prostheses manufactured using 3D printing was significantly smaller compared to that manufactured using casting methods (standard mean difference (95% CI): −0.92 (−1.45, −0.38); Z = −3.37; p = 0.0008). The estimated difference between the single and multi-unit types did not differ significantly (p = 0.3573). In the subgroup analysis for the measurement methods, the tendency of marginal discrepancy between the 3D printing and casting groups was significantly different between articles that used direct observation and those that used the silicone replica technique (p < 0.001). Metal 3D printing technologies appear reliable as an alternative to casting methods in terms of the fit of the fixed dental prostheses. In order to analyze the factors influencing manufacturing and confirm the results of this review, further controlled laboratory and clinical studies are required.

The purpose of this study was to evaluate the shear bond strength (SBS) of two different resin cements (Panavia F 2.0 (Kuraray Medical Inc, Okayama, Japan) and Variolink N (Ivoclar Vivadent AG, Schaan, Liechtenstein)) to 112 zirconia specimens with airborne-particle abrasion and 20%, 30%, or 40% hydrofluoric acid (HF) for 1 or 2 h. A total of eight specimens were used to observe the phase transformation after surface treatments. Six specimens were treated only with HF etching and the average surface roughness (Ra) was analyzed. A one-way ANOVA test was applied for SBS and the effect of HF concentration on Ra. An independent t-test was performed for the comparison of Panavia F 2.0 and Variolink N, and the influence of the HF application time on Ra. A higher HF solution increased SBS and Ra. HF etching produced a lower rate of monoclinic phase transformation. Panavia F 2.0 showed a higher SBS than Variolink N.

The fibula free flap offers several advantages in mandibular reconstruction, including an optimal length and bone quality for dental implantation; therefore, the use of this flap has become a method of choice for mandibular reconstruction. Although the development of computer-assisted surgical planning has increased the accuracy of mandibular reconstruction, some unexpected outcomes still occur in clinical settings. The patient in this report underwent mandibular reconstruction with the fibula free flap because of mandibular resection resulting from an ameloblastoma. However, unexpected movement of the grafted fibula bone had been observed, and we could not achieve a proper occlusal relationship even with implant-supported prosthesis. To resolve this problem, we corrected the position of previously grafted fibula and implants by using orthognathic surgery: sagittal split osteotomy on body and angle area and vertical osteotomy on the mandibular symphysis. After the orthognathic surgery at the previously reconstructed mandible with fibula free flap, a favorable and stable occlusal relationship could be achieved. The result demonstrated that the sagittal split osteotomy at the previous fibula free flap site can be successfully carried out to establish the proper occlusion.

PURPOSEThis study aimed to evaluate the marginal discrepancy of full-arch frameworks in implant-supported prostheses fabricated using pre-sintered soft alloy (PSA).MATERIALS AND METHODSFull-arch metal frameworks were fabricated on the edentulous implant model using casting alloy (CA), fully-sintered hard alloy (FHA), and PSA (n = 4 in each group). To evaluate the misfit of the framework to the abutments, the absolute marginal discrepancy (AMD) values of the frameworks were measured in cross-sectional images that had been drawn as part of the triple-scan protocol. The AMD values were compared among the tested alloy groups using the Kruskal-Wallis test, with a post hoc Mann-Whitney U test (α=.05).RESULTSThe FHA and PSA groups showed lower marginal discrepancies than the CA group (P<.001). However, the FHA group did not differ significantly from the PSA group.CONCLUSIONSoft alloy milling is comparable to hard alloy milling, and it is more precise than casting in terms of the marginal fit of implant-supported, full-arch prostheses.