Group 2 ITI Consensus Report: Prosthodontics and implant dentistry.

OBJECTIVES: Working Group 2 was convened to address topics relevant to prosthodontics and dental implants. Systematic reviews were developed according to focused questions addressing (a) the number of implants required to support fixed full-arch restorations, (b) the influence of intentionally tilted implants compared to axial positioned implants when supporting fixed dental prostheses (FDPs), (c) implant placement and loading protocols, (d) zirconia dental implants, (e) zirconia and metal ceramic implant supported single crowns and (f) zirconia and metal ceramic implant supported FDPs. MATERIALS AND METHODS: Group 2 considered and discussed information gathered in six systematic reviews. Group participants discussed statements developed by the authors and developed consensus. The group developed and found consensus for clinical recommendations based on both the statements and the experience of the group. The consensus statements and clinical recommendations were presented to the plenary (gathering of all conference attendees) and discussed. Final versions were developed after consensus was reached. RESULTS: A total of 27 consensus statements were developed from the systematic reviews. Additionally, the group developed 24 clinical recommendations based on the combined expertise of the participants and the developed consensus statements. CONCLUSIONS: The literature supports the use of various implant numbers to support full-arch fixed prostheses. The use of intentionally tilted dental implants is indicated when appropriate conditions exist. Implant placement and loading protocols should be considered together when planning and treating patients. One-piece zirconia dental implants can be recommended when appropriate clinical conditions exist although two-piece zirconia implants should be used with caution as a result of insufficient data. Clinical performance of zirconia and metal ceramic single implant supported crowns is similar and each demonstrates significant, though different, complications. Zirconia ceramic FDPs are less reliable than metal ceramic. Implant supported monolithic zirconia prostheses may be a future option with more supporting evidence.

In vitro effects of 2-methoxyestradiol-bis-sulphamate on the non-tumorigenic MCF-12A cell line.

A priority in recent anti-cancer drug development has been attaining better side-effect profiles for potential compounds. To produce highly specific cancer therapies it is necessary to understand both the effects of the proposed compound on cancer and on normal cells comprising the rest of the human body. Thus in vitro evaluation of these compounds against non-carcinogenic cell lines is of critical importance. One of the most recent developments in experimental anti-cancer agents is 2-methoxyestradiol-bis-sulphamate (2ME-BM), a sulphamoylated derivative of 2-methoxyestradiol. The aim of this study was to evaluate the in vitro effects of 2ME-BM on cell proliferation, morphology and mechanisms of cell death in the non-carcinogenic MCF-12A breast epithelial cell line. The study revealed changes in proliferative capacity, morphology and cell death induction in response to 2ME-BM exposure (24 h at 0.4 microM). Microscopy showed decreased cell density and cell death-associated morphology (increased apoptotic characteristics), a slight increase in acidic intracellular vesicles and insignificant ultra-structural aberrations. Mitotic indices revealed a G(2)M-phase cell cycle block. This was confirmed by flow cytometry, where an increased fraction of abnormal cells and a decrease in cyclin B1 levels were observed. These results evidently demonstrate that the non-carcinogenic MCF-12A cell line is less susceptible when compared to 2ME-BM-exposed cancer cell lines previously tested. Further in vitro research into the mechanism of this potentially useful compound is warranted.

In vitro effects of Sutherlandia frutescens water extracts on cell numbers, morphology, cell cycle progression and cell death in a tumorigenic and a non-tumorigenic epithelial breast cell line.

Sutherlandia frutescens is a South African herb traditionally used for internal cancers, diabetes, a variety of inflammatory conditions and recently to improve the overall health in cancer and HIV/AIDS patients. The in vitro effects of S. frutescens extracts were evaluated on cell numbers, morphology, cell cycle progression and cell death. Dose-dependent studies (2-10 mg/ml) revealed a decrease in malignant cell numbers when compared to their controls. S. frutescens extracts (10 mg/ml) decreased cell growth in a statistically significantly manner to 26% and 49% (P<0.001) in human breast adenocarcinoma (MCF-7) and human non-tumorigenic epithelial mammary gland cells (MCF-12A) respectively after 72 h of exposure. Cell density was significantly compromised and hypercondensed chromatin, cytoplasmic shrinking, membrane blebbing and apoptotic bodies were more pronounced in the MCF-7 cell line. Both S. frutescens-treated cell lines exhibited and increased tendency for acridine orange staining, suggesting increased lysosomal and/or autophagy activity. Flow cytometry showed an increase in the sub G(1) apoptotic fraction and an S phase arrest in both the 5 mg/ml and 10 mg/ml S. frutescens-treated cells. S. frutescens induced an increase in apoptosis in both cell lines as detected by Annexin V and propidium iodide flow cytometric measurement. At 10 mg/ml, late stages of apoptosis were more prominent in MCF-7 S. frutescens-treated cells when compared to the MCF-12A cells. Transmission electron microscopy revealed hallmarks of increased vacuolarization and hypercondensed chromatin, suggesting autophagic and apoptotic processes. The preliminary study demonstrates that S. frutescens water extracts exert a differential action mechanism in non-tumorigenic MCF-12A cells when compared to tumorigenic MCF-7 cells, warranting future studies on this multi-purpose medicinal plant in southern Africa.