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This report describes the restoration of the healed single implant in the posterior region by using a lithium disilicate crown supported by an Acuris abutment. The restored implants were placed in the premolar and molar region of both the mandible and the maxilla by using a 1-stage approach. The definitive Acuris abutment was placed after an implant healing period of at least 3 months. Definitive impressions were made at least 3 months after surgery. The precrystallized lithium disilicate crown was adapted to a laboratory abutment and evaluated. The crown was then crystallized, finished, colored, and cemented to the definitive abutment by using an adhesive resin cement. The definitive restoration engaged the abutment without the use of screws or cement. A single healed implant can be successfully restored by using a lithium disilicate restoration supported by an Acuris abutment.

Control of heat dissipation and transmission to the peri-implant area during intra-oral welding is very important to limit potential damage to the surrounding tissue. The aim of this in vitro study was to assess, by means of thermal infrared imaging, the tissue temperature peaks associated with the thermal propagation pathway through the implants, the abutments and the walls of the slot of the scaffold, generated during the welding process, in three different implant systems. An in vitro polyurethane mandible model was prepared with a 7.0 mm v-shape slot. Effects on the maximum temperature by a single welding procedure were studied using different power supplies and abutments. A total of 36 welding procedures were tested on three different implant systems. The lowest peak temperature along the walls of the 7.0 mm v-shaped groove (31.6 ± 2 °C) was assessed in the specimens irrigated with sterile saline solution. The highest peak temperature (42.8 ± 2 °C) was assessed in the samples with a contemporaneous power overflow and premature pincers removal. The results of our study suggest that the procedures used until now appear to be effective to avoid thermal bone injuries. The peak tissue temperature of the in vitro model did not surpass the threshold limits above which tissue injury could occur.

Nanoparticles (NPs) are materials with one dimension in the range of 1-100 nm. The toxicity of NPs remains widely unknown and still poses concerns, due to the peculiar characteristics of materials in the nano-size range. We analyze the toxicity of seven NPs ((Fe2O3, Fe3O4, Sb2O3, Au, TiO2, Co, and Ag) on primary cultures of human hematopoietic progenitor cells from the bone marrow of healthy donors with CFU assays, and show that antimony oxide (Sb2O3) NPs and cobalt (Co) NPs have a toxic effect, while the other NPs have no effect at the tested concentrations (5, 25 and 100 microg/ml). While Co NPs suspension is toxic to both erythroid and granulocytic-monocytic precursors, Sb2O3 NPs at 5 microg/ml are specifically toxic to erythroid colony development, suggesting a highly selective type of toxicity. With liquid culture assays we show that Sb2O3 NPs impair the proliferation of erythroid progenitors, while no toxic effect is observed when Sb2O3 NPs are added during erythroid differentiation. CFU assays and liquid culture assays on seven human cell lines of hematopoietic origin (K562, HL-60, CEM, CEM-R, Thp-1, Jurkat, and Molt-4) show that, contrary to what observed on primary cultures of bone marrow progenitors, Sb2O3 NPs have no toxic effect on proliferation of any of the cell lines, raising concerns about the use of immortalized cell lines for nanotoxicology tests.