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Objective@#To investigate the effect of denture stomatitis of selective laser melting (SLM) titanium alloy for removable partial denture frameworks.@*Methods @#Twenty patients with dentition defects in our hospital were divided into two groups according to the different methods of creating a removable partial denture framework: the SLM group and casting group. The success rate, placement rate, masticatory efficiency and incidence of denture stomatitis were compared. Experimental data were analyzed with SPSS20.0.@*Results @# The success rate of the SLM framework group was 100.00%, which was higher than that of the casting group (90.00%) (P ＜ 0.01). The rate of framework placement in the SLM group was slightly lower than that in the casting group (P ＜ 0.05). The masticatory efficiency of the SLM group was higher than that of the casting group (0.783 ± 0.030 vs. 0.699 ± 0.037, P ＜ 0.001). The incidence of denture stomatitis (10.00%) in the SLM group was significantly lower than that in the casting group (30.00%) (P ＜ 0.001). @*Conclusion @#SLM is superior to the traditional casting method in mastication efficiency and reducing the incidence of denture stomatitis. This method can meet the clinical requirements, but the accuracy of the long-term stent needs to be improved.
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Objective@#To investigate the physical properties of Ti-6Al-4V clasps generated by selective laser melting (SLM) with different construction directions and to compare these clasps with cast clasps, which could provide a basis for fabricating SLM clasps with high precision and excellent mechanical properties. @*Methods@# Ti-6Al-4V clasps were fabricated by SLM at 0 degrees (SLM0 group), 45 degrees (SLM45 group) and 90 degrees (SLM90 group) (n = 12). Twelve clasps were cast by the casting method as the control group. Meanwhile, four metal abutments were cast randomly as the abutments of the four groups. X-ray was used to detect cracks in the clasps of each group. The roughness of the clasps was measured by confocal microscopy, the fitness tests between clasps and abutment were processed by stereomicroscopy, and the microstructure of clasps in each group was observed under a metallographic microscope to evaluate the physical properties.@*Results @# There were 0-8 visible cracks in the casting group but no obvious defects in the SLM groups. The maximum surface roughness was observed in the cast group (18.102 ± 3.762) μm, while the minimum roughness was observed in the SLM90 group (5.942 ± 1.486) μm (P < 0.05). There was no statistically significant difference in surface roughness between the SLM0 group [(8.711 ± 2.378) μm] and the SLM45 group [(8.513 ± 1.161) μm]. Fitness was worst in the casting group [(68.445 ± 14.876) μm] and best in the SLM90 group [(33.417 ± 5.880) μm] (P < 0.05). There was no statistically significant difference in fitness between the SLM0 group [(52.917 ± 12.102) μm] and the SLM45 group [(50.889 ± 7.011) μm]. In addition, the growth direction of the β grains was roughly parallel to the build direction, and acicular α grains were present between β grains. SLM was composed of fine grains, while the cast group had large grains.@* Conclusions@# Specimens generated by SLM had finer grains than cast specimens. In addition, SLM90 clasps had the highest fitness and the lowest surface roughness.
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Objective @#To investigate the clinical efficacy of prosthesis retained by metal clasp and flexible clasp in the repair of type Ⅴ maxillary defects after tumor resection. @*Methods@#23 maxillary tumor surgical patients were selected in this study and restored with maxillofacial prosthesis. Total 24 prosthesis combined with metal clasp and flexible dentures were followed up for half a year to 2 years. @*Results @#After the application of prosthesis, better maxillofacial appearances are presented in all of the patients, Watian drinking water tests are improved to grade Ⅰ or Ⅱ from grade Ⅳ or Ⅴ in 21 patients, there was significant difference (P < 0.05); Soft diet can be masticated on affected side in 15 patients; The mean speech intelligibility score with and without prosthesis were (83.2 ± 7.3)% and (36.6 ± 5.6)%, there was significant difference (P < 0.05); Favorable hygienic situations of oral cavity and prosthesis are maintained in 18 patients.@*Conclusion @#Prosthesis combined with metal clasp and flexible denture performed favorable clinical efficacy and contributed to improve the living quality and mental health after tumor resection.