Production of bone mineral material and BMP-2 in osteoblasts cultured on double acid-etched titanium.

BACKGROUND: The study of osteoblasts and their osteogenic functions is essential in order to understand them and their applications in implantology. In this sense, this study try to study BMP-2 production and bone matrix deposition, in addition to other biological variables, in osteoblasts cultured on a rough double acid-etched titanium surface (Osseotite®, Biomet 3i, Palm Beach Garden, Florida, USA) in comparison to a smooth titanium surface (machined) and a control Petri dish. MATERIALS AND METHODS: An in vitro prospective study. NHOst human osteoblasts from the femur were cultured on three different surfaces: Control group: 25-mm methacrylate dish (n = 6); Machined group: titanium discs with machined surface (n = 6) and Experimental group: titanium discs with a double acid-etched nitric and hydrofluoric Osseotite® acid surface (n = 6). A quantification of the mitochondrial membrane potential, and studies of apoptosis, mobility and adhesion, bone productivity (BMP-2) and cellular bone synthesis were carried out after culturing the three groups for forty-eight hours. RESULTS: A statistically significant difference was observed in the production of BMP-2 between the experimental group and the other two groups (22.33% ± 11.06 vs. 13.10% ± 5.51 in the machined group and 3.88% ± 3.43 in the control group). Differences in cellular bone synthesis were also observed between the groups (28.34% ± 14.4% in the experimental group vs. 20.03% ± 6.79 in the machined group and 19.34% ± 15.93% in the control group). CONCLUSIONS: In comparison with machined surfaces, Osseotite® surfaces favor BMP-2 production and bone synthesis as a result of the osteoblasts in contact with it.

Hydrodynamic ultrasonic maxillary sinus lift: review of a new technique and presentation of a clinical case.

OBJECTIVES: Placing implants in the posterior maxillary area has the drawback of working with scarce, poor quality bone in a significant percentage of cases. Numerous advanced surgical techniques have been developed to overcome the difficulties associated with these limitations. Subsequent to reports on the elevation of the maxillary sinus through the lateral approach, there were reports on the use of the crestal approach, which is less aggressive but requires a minimal amount of bone. Furthermore, it is more sensitive to operator technique, as the integrity of the sinus membrane is checked indirectly. The aim of this paper is to review the technical literature on minimally invasive sinus lift and compare the advantages of different techniques with Intralift™, a new technique. STUDY DESIGN: The present study is a review of techniques used to perform minimally invasive sinus lift published in Cochrane, Embase and Medline over the past ten years and the description of the crestal sinus lift technique based on minimally invasive piezosurgery, with the example of a case report. RESULTS: Only eight articles were found on minimally invasive techniques for sinus lift. The main advantage of this new technique, Intralift, is that it does not require a minimum amount of crestal bone (indeed, the smaller the width of the crestal bone, the better this technique is performed). The possibility of damage to the sinus membrane is minimised by using ultrasound based hydrodynamic pressure to lift it, while applying a very non-aggressive crestal approach. CONCLUSIONS: We believe that this technique is an advance in the search for less traumatic and aggressive techniques, which is the hallmark of current surgery.

Mechanical resistance of zirconium implant abutments: a review of the literature.

The increase of aesthetic demands, together with the successful outcome of current implants, has renewed interest in the search for new materials with enough mechanical properties and better aesthetic qualities than the materials customarily used in implanto-prosthetic rehabilitation. Among these materials, zirconium has been used in different types of implants, including prosthetic abutments. The aim of the present review is to analyse current scientific evidence supporting the use of this material for the above mentioned purposes. We carried out the review of the literature published in the last ten years (2000 through 2010) of in vitro trials of dynamic and static loading of zirconium abutments found in the databases of Medline and Cochrane using the key words zirconium abutment, fracture resistance, fracture strength, cyclic loading. Although we have found a wide variability of values among the different studies, abutments show favourable clinical behaviour for the rehabilitation of single implants in the anterior area. Such variability may be explained by the difficulty to simulate daily mastication under in vitro conditions. The clinical evidence, as found in our study, does not recommend the use of implanto-prosthetic zirconium abutments in the molar area.

Prognostic value of flow cytometric DNA analysis in non-small-cell lung cancer: rationale of sequential processing of frozen and paraffin-embedded tissue.

The objective of this study was to determine the prognostic information provided by flow cytometric DNA analysis in non-small-cell lung cancer. Lung samples of 132 consecutive patients submitted to surgery were prospectively processed. When no aneuploid populations were detected in fresh frozen samples, the process continued as a second step in paraffin-embedded tissue, consuming all the tumor available. The influence of ploidy on the postoperative outcome was studied by both a univariate and a multivariate analysis. Aneuploidy was found in 81 patients (61.4%). Fourteen patients showed no aneuploidy in fresh frozen samples; and only after further analysis in paraffin-embedded tissue was abnormal DNA detected. Overall, the 36-month survival was 69% for the diploid group and 24% for the aneuploid group (p = 0.0006). Including subjects submitted to complete tumor removal (stages I, II, and IIIA) in a multivariate analysis adjusted for TNM stage and histologic type, bearers of aneuploid tumors exhibited a higher risk of relapse (hazard ratio 2.65; CI 95% 1.5-4.66;p = 0.004) or death (hazard ratio 2.17; CI 95% 1.08-4.39;p = 0.032) than patients with diploid tumors. DNA ploidy resulted an independent prognostic factor of survival and tumor relapse in completely resected non-small-cell lung cancer. Sequential analysis of fresh and paraffin-embedded samples can help avoid the bias due to intratumoral DNA content heterogeneity. DNA ploidy could be an useful parameter in any future multifactorial analysis of outcome in such tumors.

Long-term performance of porcine heart valve bioprostheses.

To assess the results after long-term implantation of porcine bioprosthetic heart valves, 320 patients with 381 valves were retrospectively reviewed. This group included all patients receiving one such xenograft in the mitral or aortic position (or both) in our institution between June 1974 and December 1976. The patients had a follow-up of 9-11.5 years. Actuarial patient survival rats (hospital mortality excluded) were 85%-90% at 6 years and 68%-79% at 11.5 years. Thromboembolic episodes did not show any significant clustering over the first weeks or months, in fact, they appeared at a constant rate. Actuarial rates of freedom from thromboembolism were greater than 90% for aortic patients at 11.5 years and greater than 80% for mitral and mitroaortic patients at 11.5 years. The linearized rate of anticoagulant-related haemorrhage for the whole group of patients was 0.4 events/100 patient years with a related mortality of 0.2 events/100 patient years. Prosthetic valve endocarditis and paravalvular leak appeared at linearized rates of 0.6 (0.1 of related mortality) and 0.4 (0.1 of related mortality) events/100 patient years. Primary tissue valve failure constituted the most prevalent complication (82 cases) in the long term but did not significantly worsen patient survival. Actuarial rates of freedom from primary tissue failure were 91% +/- 2% at 6, and 40% +/- 14% at 11.5 years for mitral valves, and 95% +/- 4% at 6 and 64% +/- 6% at 11.5 years for aortic valves.(ABSTRACT TRUNCATED AT 250 WORDS)

The behavior of pericardial versus porcine valve xenografts in the growing sheep model.

The comparative long-term behavior of the pericardial versus the porcine bioprostheses is not yet known. The need for long follow-up times to answer this question makes the growing sheep model an attractive alternative, given its ability to induce early valve degeneration. Sixty-three sheep, 12 to 16 weeks old, were operated on and received 39 porcine (11 Xenomedica, 10 Carpentier-Edwards S, nine Hancock I standard, and nine Hancock I T6-treated) and 24 pericardial (14 Mitroflow and 10 Ionescu-Shiley low profile) prostheses of clinical quality in the tricuspid position. Of the 52 operative survivors (32 received porcine valves and 20 received pericardial bioprostheses), six animals (five pericardial and one porcine) were eliminated because of bioprosthetic infection. Late sudden death before the scheduled killing occurred significantly more often (p less than 0.0001) in the pericardial (8/15 or 53%) than in the porcine group (1/31 or 3%). Calcium content of the explanted valves was significantly correlated with time in the pericardial group and the Xenomedica porcine prostheses (p less than 0.05) but not in the Hancock I and Carpentier-Edwards S valves, where it was only marginally significant (0.1 greater than p greater than 0.05). Linear regression analysis of tissue calcium content showed a similar slope for the pericardial group and Xenomedica porcine valves, in comparison with the remaining porcine valves. Comparison between the two lines using covariance analysis demonstrated a statistically significant difference between them, which shows that the pericardial and Xenomedica porcine valves appear to reach higher levels of calcification in a shorter follow-up time than the Hancock I, standard and T6-treated, and the Carpentier-Edwards S valve in this animal model.