PIP IMPLANTS--CURRENT KNOWLEDGE AND LITERATURE REVIEW.

Non-compliance with the production process and use of non-certified materials du- ring production of PIP implants opened an extensive debate regarding regulation and control mechanisms during their production, but the question of health safety of breast implants in general was also reopened. Production of breast implants is subject to various control mechanisms in each country and it is necessary to unify and coordinate such mechanisms. PIP implants were on the market for more than 15 years and in this period the production process and used materials were being changed purposely and without control, which resulted in production of implants with poor quality capsule filled with non-certified silicon gel. There were around 600,000 of these erroneous implants produced. Despite demonstrable harmfulness of the PIP implants, the current studies were not able to reliably confirm health hazard of these implants. Financial costs together with the inability to demonstrate health risk of PIP implants is the reason why the question to widely replace these implants was not solved and each state has a different opinion on this issue.

Effect of dentin desensitizing procedures on methyl methacrylate diffusion through dentin.

BACKGROUND: Acrylic and bisacryl resins are widely used both during the temporization phase as well as for provisional restorations and the effect of external agents on dentin sensitivity can be reduced by the obliteration of the tubules. OBJECTIVE: The purpose of this study was to evaluate diffusion of methyl methacrylate monomer through dentin by high performance liquid chromatography (HPLC) after three different desensitizing procedures during the fabrication of two different provisional crown materials. MATERIALS AND METHODS: Forty extracted restoration and caries free human premolar teeth were used in this study. Thermoplastic vacuum formed material was used as a matrix to fabricate provisional restorations for each tooth before crown preparation. Teeth were prepared for a metal supported ceramic crown with 1 mm shoulder margins and then crown parts were separated from cementoenamel junction with a carborundum disk perpendicular to the long axis of the teeth. To the cementoenamel junction of each tooth a polypropylene chamber was attached that contains 1.5 cm 3 of deionized distilled water. Prepared teeth were divided into four groups ( n = 10) including control, desensitizing agent (DA) application, neodymium-doped yttrium aluminum garnet (Nd: YAG) laser irradiation (LI), and LI after DA application groups. After application of DA (except control) each group were divided into two subgroups for fabrication of provisional restorations ( n = 5). Two autopolymerizing provisional materials (Imident (Imicryl) and Systemp C and B (Ivoclar, vivadent)) were used to fabricate provisional restorations using the strips. Water elutes were analyzed by HPLC at 10 min and 24 h. RESULTS: The monomer diffusion values varied statistically according to desensitizing procedures, provisional resin systems, and the time periods. Monomer diffusion through dentin surfaces desensitized with Nd: YAG LI after DA application was the lowest. CONCLUSIONS: Nd: YAG LI in association with DA application is an effective combination to eliminate monomer diffusion through dentin to pulpal chamber.