Cytotoxicity and oxidative stress induced by nickel and titanium ions from dental alloys on cells of gastrointestinal tract.

The aim was to explore the biological effect of nickel (Ni) and titanium (Ti) ions released from dental alloys. NiTi alloy were exposed to 40 mL of artificial saliva (pH = 4.8, t = 37 °C). The dynamics of Ni and Ti ions release during corrosion were recorded on the 3th, 7th and 14th day. Biological effect of Ni and Ti ions released from alloy was explored on cell lines of human tongue CAL 27, liver Hep G2 and colon Caco-2. Neutral Red uptake assay for the estimation of cell viability/cytotoxicity and 2',7'-dichlorofluorescein diacetate fluorimetric assay for reactive oxygen species were used. Cells were exposed to the following concentration of corrosion products: 5.0×, 1.0×, 0.5 and 0.1× during the period of 24, 48 and 72 h. To check the effect of each metal separately, cells were exposed to nickel-chloride and titanium-dioxide of corresponding concentration. The release of Ni is higher than of Ti (15.1-30.4 µg/L for Ni and 9.0-17.3 µg/L for Ti, respectively) and 5× higher concentrations are needed to induce cytotoxic effect. Ni and Ti ions alone do not induce a major cytotoxic effect, but their combination does indicating their synergistic effect. Increase in concentration of Ni and Ti tends to increase cytotoxicity, Ti more than Ni. Cytotoxicity and induction of free radicals are in strong positive linear correlation. Ions released from NiTi alloy during 14 days do not induce significant cytotoxic effect and would not have a clinically important impact. Cytotoxic effect is largely the result of the induction of free radicals.

[Therapeutic efficiency in multisegmental fusions of the lumbar spine]. / Therapeutische Effizienz langstreckiger Fusionen im Bereich der LWS.

AIM: The aim of this study was to evaluate of the efficiency of an internal fixateur used since 1998 in multisegmental spondylodesis of the lumbar spine. METHOD: The prospective study included 105 patients with degenerative changes or instabilities of the lumbar spine, who underwent an anterior and posterior stabilisation of more than two segments. The minimum period of follow-up was more than 6 months. There were several objective scores used for the evaluation of the efficiency (Oswestry score/visual analogue scale [VAS]). In addition, the quality of the new internal implant was assessed concerning the rate of loosening and failure of the implant. This new internal fixateur, produced as a titanium alloy, consists of pedicle screws and longitudinal rods with 5 mm diameter and connection elements. Upon pulling the nut a square stabilised situation is created. Altogether the three-segmental stabilisations predominated (n=77), 23 patients received a four-segmental, four patients a five-segmental stabilisation and one received a stabilisation of six levels, mainly involving the segments L3/4 to L5/S1. Because of severe deformities in 14 cases the pedicle screws were applied by computer-assisted navigation (Navitrak). RESULTS: In 12 patients (11.4%) radiological signs of loosening of the inserted pedicle screws in the vertebra were diagnosed. The radiological analysis resulted in pseudarthrosis of 4 (1.2%) of the 349 amalgamated segments. There were no cases of material failure. The average value of the pain score preoperatively (VAS) was 7.7 (5-10, SA 1.3) and postoperatively 4.6 (1-10, SA 1.8). With regard to the Oswestry disability index the preoperative average value amounted to 51.9% (30-91, SA 11.8) and postoperatively 35% (12-74, SA 11.8). In all 98 (93.3%) patients were satisfied, 7 (6.7%) patients reported a decline of the subjective outcome. CONCLUSION: This system achieved a high degree of patient satisfaction and showed a low rate of pseudarthrosis. Furthermore, it can be inserted for short and long fusions, as well in deformities.

[Epithelioid hemangioma of the popliteal artery]. / Epitheloides Hämangiom der A. poplitea.

We report the case of a 37-year-old patient with an epithelioid haemangioma arising from the third segment of the popliteal artery and the tibio-peroneal trunk. As far as we know this is the first description of this tumour originating in an artery of this order. One year after excision of the tumour mass and vascular reconstruction the patient has recovered and shows no evidence of recurrence. Clinical manifestation and morphological characteristics of this rare lesion are described in this article.