The properties and performance of a new low-monomer cement were examined in this prospective randomized, controlled RSA study. 5-year data have already been published, showing no statistically significant differences compared to controls. In the present paper we present the 10-year results.
44 patients were originally randomized to receive total hip replacement with a Lubinus SPII titanium-aluminum-vanadium stem cemented either with the new Cemex Rx bone cement or with control bone cement, Palacos R. Patients were examined using RSA, Harris hip score, and conventional radiographs.
At 10 years, 33 hips could be evaluated clinically and 30 hips could be evaluated with RSA (16 Cemex and 14 Palacos). 9 patients had died and 4 patients were too old or infirm to be investigated. Except for 1 hip that was revised for infection after less than 5 years, no further hips were revised before the 10-year follow-up. There were no statistically significant clinical differences between the groups. The Cemex cement had magnitudes of migration similar to or sometimes lower than those of Palacos cement. In both groups, most hips showed extensive radiolucent lines, probably due to the use of titanium alloy stems.
At 10 years, the Cemex bone cement tested performed just as well as the control (Palacos bone cement).
OBJECTIVE: For long-term stability the adhering interfaces of an implant-retained supraconstruction of titanium/carbon-graphite fiber-reinforced (CGFR) polymer/opaquer layer/denture base polymer/denture teeth must function as a unity. The aim was to evaluate adhesion of CGFR polymer to a titanium surface or CGFR polymer to two different opaquer layers/with two denture base polymers. MATERIALS AND METHODS: Titanium plates were surface-treated and silanized and combined with a bolt of CGFR polymer or denture base polymer (Probase Hot). Heat-polymerized plates of CGFR polymer (47 wt% fiber) based on poly(methyl methacrylate) and a copolymer matrix were treated with an opaquer (Sinfony or Ropak) before a denture base polymer bolt was attached (Probase Hot or Lucitone 199). All specimens were heat-polymerized, water saturated (200 days) and thermally cycled (5000 cycles, 5/55 degrees C) before shear bond testing. RESULTS: Silicatized titanium surfaces gave higher bond strength to CGFR polymer (16.2+/-2.34 and 18.6+/-1.32) MPa and cohesive fracture than a sandblasted surface (5.9+/-2.11) MPa where the fracture was adhesive. The opaquer Sinfony gave higher adhesion values and mainly cohesive fractures than the opaquer Ropak. Different surface treatments (roughened or polished) of the CGFR polymer had no effect on bond strength. SIGNIFICANCE: The fracture surfaces of silicatized titanium/CGFR polymer/opaquer layer (Sinfony)/denture base polymers were mainly cohesive. A combination of these materials in an implant-retained supraconstruction is promising for in vivo evaluation.
The aim of the present study was testing the hypothesis that the adoption of nickel-titanium rotary instrumentation (NTRI) will improve the technical quality of root-fillings. The investigation was carried out within a mandatory continuing education program (CEP) for general dental practitioners (GDPs). The study was conducted amongst GDPs employed by the Public Dental Health Service in the County of Stockholm. Identical questionnaires were distributed before the CEP (Pre-Q) and 9 to 12 months after the course (Post-Q). The CEP consisted of two parts: lectures and hands-on training. From each GDP, radiographs of two cases completed before the course and two cases treated 9-12 months after the course were randomly selected. Primarily molars were selected for evaluation. The radiographs were individually evaluated by two endodontists. Teeth treated before and after training were presented in random order. Adoption rate of NTRI increased from 35% to 75%. Cases from 124 GDPs were included in the final analysis. The rate of good quality root-fillings increased from 27% to 49% (p
An electromechanical drill with titanium barrels was used to recover a 63.7 m long firn core from Devon Island Ice Cap, Nunavut, Canada, representing 155 years of precipitation. The core was processed and analysed at the Geological Survey of Canada by following strict clean procedures for measurements of Pb and Cd at concentrations at or below the pg g(-1) level. This paper describes the effectiveness of the titanium drill with respect to contamination during ice core retrieval and evaluates sample-processing procedures in laboratories. The results demonstrate that: (1) ice cores retrieved with this titanium drill are of excellent quality with metal contamination one to four orders of magnitude less than those retrieved with conventional drills; (2) the core cleaning and sampling protocols used were effective, contamination-free, and adequate for analysis of the metals (Pb and Cd) at low pg g(-1) levels; and (3) results from 489 firn core samples analysed in this study are comparable with published data from other sites in the Arctic, Greenland and the Antarctic.
The Norwegian Armed Forces' shooting ranges contain contamination by metals such as lead (Pb) and copper (Cu) and are often used as grazing pastures for livestock. To determine whether the sheep were at risk from grazing at a shooting range in Nord-Trøndelag (the Leksdalen shooting field), a study was conducted wherein the aim was to determine the amount of soil the sheep were eating, the accumulation of Cu and Pb in the livers of lambs grazing on the shooting ranges, and the accumulation of Pb and Cu in the grass. The grazing behavior of the sheep was mapped using GPS tracking and wildlife cameras. Soil, grass, feces, and liver samples were collected. All the samples were analyzed for Pb, Cu, and molybdenum (Mo), and soil and feces were also analyzed for titanium (Ti). Mean concentrations in grass, soil, feces, and liver was 41-7189, 1.3-29, 4-5, and 0.3 mg/kg Pb, respectively, and 42-580, 4.2-11.9, 19-23, and 273 mg/kg Cu, respectively. The soil ingestion rate was calculated using Ti in feces and soil. From these results, the theoretical dose of Cu and Pb ingested by grazing sheep was calculated. The soil ingestion rate was found to be 0.1-0.4%, significantly lower than the soil ingestion rate of 5-30% usually used for sheep. Little or no accumulation of Cu and Pb in the grass was found. There was no difference between the metal concentrations in the washed and unwashed grass. According to the calculated dose, the sheep were at little or no risk of acute or chronic Pb and Cu poisoning from grazing on the Leksdalen shooting range. The analysis of liver samples showed that lambs grazing on the shooting range did not have higher levels of Cu or Pb than lambs grazing elsewhere. None of the lambs had concentrations of Cu or Pb in their livers indicating poisoning.
Nickel titanium shape memory metal alloy Nitinol (NiTi) has been used in dental wares and in gastrointestinal surgery. Nitinol is a promising implant material in orthopedics, but its biocompatibility, especially in long-term implantation is not confirmed yet. We studied Nitinol's effect on a cell culture model. Comparisons to stainless steel, pure titanium and pure nickel were performed. The effects of Nitinol on cell death rate, the apoptosis rate and the formation of local contacts were studied on rat osteosarcoma cell line ROS-17 in 48-h cultures. The cell death rate was assessed with combined calcein-ethidium-homodimer labelling. The amount of dead cells 1000 cells were as follows: four in the NiTi, 21 in the Stst, 4.8 in the Ti and 51 in the Ni group. In the NiTi and Ti groups, the number of dead cells was significantly lower (p
The results of treatment of the first 12 Danish patients with the Brånemark titanium implant system and the bone-anchored hearing aid (BAHA) are reported. All implants were osseointegrated, judged by 99mTC-scintigraphy, X-ray examination and clinical examination. Skin reactions were few, transient and short lasting. The patients experienced the BAHA to be superior to both conventional BC hearing aids and AC hearing aids in practically all respects. Speech discrimination scores in quiet and in noise were similar for the 3 types of hearing aids.
Osseointegration, the direct contact between an implant surface and bone tissue, plays a critical role in interfacial stability and implant success. Analysis of interfacial zones at the micro- and nano-levels is essential to determine the extent of osseointegration. In this paper, a series of state-of-the-art microscopy techniques are used on laser-modified implants retrieved from humans. Partially laser-modified implants were retrieved after two and a half months' healing and processed for light and electron microscopy. Light microscopy showed osseointegration, with bone tissue growing both towards and away from the implant surface. Transmission electron microscopy revealed an intimate contact between mineralized bone and the laser-modified surface, including bone growth into the nano-structured oxide. This novel observation was verified by three-dimensional Z-contrast electron tomography, enabling visualization of an apatite layer, with different crystal direction compared with the apatite in the bone tissue, encompassing the nano-structured oxide. In conclusion, the present study demonstrates the nano-scale osseointegration and bonding between apatite and surface-textured titanium oxide. These observations provide novel data in human specimens on the ultrastructure of the titanium-bone interface.