The service life of a facial prosthesis is about six months as a result of the impairment in its mechanical or physical properties; thus, introducing a new reinforced maxillofacial silicone material can help in fabricating a long service life prosthesis that eliminates the burden for the patients both financially and psychologically. In this study, forty samples were fabricated by adding different concentrations of CaCO 3 -SiO 2 nanoparticles composite to maxillofacial silicone elastomer. These samples were divided into four groups, each one containing ten samples according to the concentration of the fillers (0%, 1%, 2% and 3%). All samples were tested for tear strength and hardness tests. The study results show that CaCO 3 -SiO 2 nanoparticles composite has a significant effect on both conducted tests. It can be concluded that reinforcing the silicone matrix with 2% CaCO 3 -SiO 2 nanoparticles composite can improve the tear strength of the tested silicone and increase its hardness.

Background The application of nanoscale surface modification was found to be useful in the improvement of osseointegration of endosseous dental implants. The fluorapatite (FA)/alumina (Al 2 O 3 ) mixture is recognized for its outstanding bioinertia and can significantly increase the biocompatibility and bioactivity of biomaterials. Objective The aim of the present work was to evaluate the bone response to nano-alumina- and fluorapatite-coated dental implants using rabbit tibiae. Material and Methods The coating was performed using the dip-coating method. Commercially pure titanium screw-type implants were used as a control group. The coated implants were the experimental group. Each group consisted of 12 screws that were surgically implanted in 6 healthy New Zealand rabbits. Histological and histomorphometric evaluations were performed at the bone to implant contact (BIC) interface, bone fraction area occupancy (BAFO) and fibrous tissue at 2 and 6 weeks of healing. Results This analysis showed that the coated implants had more rapid osseointegration than the control group, with a significant difference after 2 and 6 weeks of healing for both groups. The histomorphometric evaluation demonstrated higher values for BIC% and BAFO% and lower values of fibrous tissue in the mixture-coated Ti implants than in the control group. Conclusion The current study suggested that the nano-alumina and fluorapatite mixture coating is a favourable candidate for rapid osseointegration over uncoated implants.

During prosthodontic clinical practice, the most commonly reported type of failure is the debonding of teeth to the denture base. Incompatible surface conditions at the tooth/denture base interface result in a lack of bonding. This study aimed to study the influence of different surface modifications of acrylic teeth and thermocycling on shear bond strength to polycarbonate denture base material. Eighty cylinder-shaped samples were fabricated. The tested samples were divided into 4 groups (n = 20). Group A represents the control group, group B represents the mechanical modification of the tooth, while group C and group D represent the chemical treatment of the tooth with ethyl acetate and bonding agent, respectively. Each group was further subdivided into 2 categories depending on the thermocycling procedure (N = 10). All samples were tested for shear bond strength tests. A computer-controlled universal testing machine performed the shear bond test at a 0.5 mm/min crosshead speed. Three-way ANOVA ( P = 0.05 ) was used for the statistical analysis of the data. Results show that shear bond strength was significantly affected by the surface treatment, whether it is mechanical or chemical ( P ≤ 0.01 ) (B > D > C) compared with a control group (A). However, thermocycling has a nonsignificant decrease in the bond strength values in all experimental groups ( P > 0.05 ) (B > D > C > A). The mechanical treatment by creating retentive holes (B) provides better results than the chemical surface treatment with a bonding agent and ethyl acetate (D and C, respectively). This study concluded that various surface conditioning methods affect the bonding strength of acrylic teeth and polycarbonate denture base material with no effect of thermocycling.