Only 16.7% of dentures worn by the elderly are properly cleaned. Older dentures tended to be dirtier than newer ones. There was a significant correlation between poor denture hygiene and prevalence of Candida.

The purpose of this study was to measure and compare the colour stability of three porcelain repair materials (Charizma, Clearfil and Silux Plus) with an all-ceramic material following accelerated ageing. Three composites and one ceramic control were subjected to accelerated ageing for a period of 300 h. Initial specimen colour parameters were determined in the Commission International de I'Eclairage Lab (CIELAB) colour order system with a colorimeter. Colour changes were calculated before (DeltaE) and after 300 h of accelerated ageing (DeltaE*). Colour difference data were subjected to one-way analysis of variance (anova) followed by Duncan's test to examine the interaction between material and time interval of ageing. There were no significant difference between DeltaL values of Porcelain-Charizma and Porcelain-Silux Plus. All mean DeltaL* values were negative after 300 h ageing. Porcelain-Silux Plus demonstrated the highest DeltaL* of the investigated groups. There were significant differences between baseline 300-h aged specimens with respect to Deltaa*, Deltaa for either of the investigated materials. For Silux Plus, Deltaa and Deltaa* values were significantly higher than the others. Significant differences were observed between baseline and 300-h values for Deltab and Deltab*. Deltab and Deltab* values were significantly higher for Silux Plus. There were significant differences between baseline and 300-h values of colour difference, DeltaE, DeltaE*. Highest DeltaE* value was obtained using the microfilled composite, Silux Plus. Lowest value of DeltaE was recorded with the hybrid composite, Charizma.

summary  Titanium has become a material of great interest in prosthodontics in recent years because of its excellent biocompatibility, corrosion resistance and desirable physical and mechanical properties. In this study, we determined the influence of dental cements on the passivation of titanium. We developed experimental electrodes that associate titanium and dental cements. Polarization resistance of titanium electrodes has been determined for uncovered metal and electrodes covered with five different dental cements. Coverage with zinc eugenate led to more resistance to corrosion, but fluorinated composite such as glass–ionomer and zinc phosphate coverage increased the corrosion susceptibility.

Various new indirect composite materials have been developed with required advantages. In this study three indirect composite material (Artglass, Belleglass HP, Targis) were tested for flexural strength, fracture toughness, wear resistance and hardness against Filtek P60 and Z‐100. Five specimens of each material were fabricated according to the manufacturer's directions. The flexural strength and fracture toughness was measured using the bending test. The wear test was performed to accelerated wear in a toothbrushing apparatus. Vickers hardness was measured for each of the tested materials. The statistical tests used for flexural strength, fracture toughness, wear and hardness were One‐way ANOVA and Kruskal–Wallis test. The level of statistical significance chosen was p = 0.05. Results of the study showed that Filtek P60 was superior to the other composites in all tests. Significant differences were found among the materials. The differences in flexural strength, fracture toughnes, wear and hardness may have been due to differences in chemistry or method of polymerization of the composites. Copyright © 2003 John Wiley & Sons, Ltd.

The objective of this study was to determine the flexural strength, flexural modulus, Vickers hardness of a packable composite (Surefil), and an ormocer (Definite) in comparison with a microhybrid composite (Z‐100), a microfil composite (Silux Plus) and a polyacid‐modified composite resin (Dyract). Flexural strength and flexural modulus were determined using a three‐point bending device. Microhardness was measured with a Vickers indentor. The specimens of each material were prepared according to manufacturer's instructions. The specimens were stored in artificial saliva at pH 6, all at 37°C. The groups were tested at the beginning of the test, at 3 months and at 6 months. Flexural strength values of Surefil and Definite showed a progressive increase. The highest MPa values were determined for Surefil (134.4 MPa) and the lowest MPa values were obtained for Dyract (59.6 MPa). The highest flexural modulus values were revealed for Surefil (10.000 GPa). Z‐100, Silux Plus and Definite showed a tendency to decline in relation to time for their flexural modulus. GPa values of Silux Plus were stable at 3 and 6 months. Vickers hardness numbers showed that Surefil was the hardest and Dyract was the weakest material. Copyright © 2003 John Wiley & Sons, Ltd.