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Background. Porcelain is brittle and in many situations it requires replacement in fractured or chipped restorations. The prospects exist in improving the strength of feldspathic porcelain to widen its applications. This study evaluated the fracture toughness of feldspathic porcelain after incorporation of silver and titanium nanoparticles at varying concentrations (0.5 wt%, 1 wt%, 1.5 wt% and 2 wt%). Methods. Test specimen dimensions were standardized to ASTM C1421–16 standards and a three-point flexure test was carried out to evaluate fracture toughness. A total of 330 samples were fabricated and broadly divided into three groups. Group I (titanium nanoparticles) and group II (silver nanoparticles) were further subdivided into 5 groups (0 wt%, 0.5 wt%, 1 wt%, 1.5 wt% and 2 wt%) for fracture toughness analysis, with each group consisting of 30 samples. Group III contained the superior concentration of both titanium and silver nanoparticles. The fracture toughness (KIC) was calculated using indentation fracture method and microstructure observations were made using scanning electron microscopy. The KIC values were compared and evaluated using one-way ANOVA. Results. Data were analyzed using one-way ANOVA and Tukey’s HSD post hoc test multiple comparisons. The mean values of group I, group II and group III were 1.949 MPa.m1/2, 2.002 MPa.m1/2 and 1.330 MPa.m1/2 , respectively. Conclusion. The results revealed that the samples reinforced with titanium and silver nanoparticles showed significant increases in fracture toughness. The blending of superior concentration of both titanium and silver nanoparticles decreased fracture resistance.

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PURPOSEThis pilot study was to find the influence of complete denture on the brain activity and cognitive function of edentulous patients measured through Electroencephalogram (EEG) signals.MATERIALS AND METHODSThe study recruited 20 patients aged from 50 to 60 years requiring complete dentures with inclusion and exclusion criteria. The brain function and cognitive function were analyzed with a mental state questionnaire and a 15-minute analysis of power spectral density of EEG alpha waves. The analysis included edentulous phase and post denture insertion adaptive phase, each done before and after chewing. The results obtained were statistically evaluated.RESULTSPower Spectral Density (PSD) values increased from edentulous phase to post denture insertion adaption phase. The data were grouped as edentulous phase before chewing (EEG p1-0.0064), edentulous phase after chewing (EEG p2-0.0073), post denture insertion adaptive phase before chewing (EEG p3-0.0077), and post denture insertion adaptive phase after chewing (EEG p4-0.0096). The acquired values were statistically analyzed using paired t-test, which showed statistically significant results (P<.05).CONCLUSIONThis pilot study showed functional improvement in brain function of edentulous patients with complete dentures rehabilitation.

The aim of this study was to investigate the flexural strength of heat cure acrylic resin reinforced with varying concentration copper nanoparticles. The study followed ISO 20795-1-2013 guidelines for estimating the flexural strength. Hundred samples of heat cure acrylic resin of dimension were fabricated. The study had five groups and each group had 20 samples. The samples were grouped as per the concentration of copper (Cu) nanoparticles in acrylic. Three-point bending flexural strength was evaluated with universal testing machine. The load was directed at the midpoint of the sample at a cross-sectional speed of 5 mm/min. The fractured load was recorded and flexural strength was estimated. The data were statistically analyzed with analysis of variance and the post hoc test. The results displayed improved flexural strength in lower Cu concentrations. The increase in flexural strength was observed in 1% (78.38 MPa), 2% (73.08 MPa), and 3% (73.08 MPa) of Cu nanoparticles and it decreased beyond 3% increase in Cu nanoparticles. The tests were statistically insignificant (P <.05). The results concluded that the optimal concentration of Cu nanoparticles to be reinforced with heat cure PMMA is 1 gm. The flexural strength decreased with an increase in concentration of Cu nanoparticles.