title: Effect of short-time povidone-iodine application on osteoblast proliferation and differentiation.
abstract: OBJECTIVE
  Povidone-iodine [polyvinylpyrrolidone-iodine complex (PVP-I)] is a broad-spectrum antimicrobial agent, frequently used in dentistry. In this study we investigated the short- and longterm effects on osteoblast number, viability, and function after short exposure to PVP-I with and without additional bone-morphogenetic protein-2 (BMP-2).
  
  
  METHODS
  Confluent osteoblast-like cell line (MC3T3-E1, subclone 24) cultures were exposed to pure PVP-I solution (7.7 mg/ml) and dilutions of 1:10, 1:100 and 1:1000 for 10 seconds and washed with phosphate buffer solution. Cell proliferation and viability was determined by MTT and differentiation status by alkaline phosphatase (ALP) activity 6 days after initial plating. In a separate experiment, long-term cell proliferation, viability and function were assessed 4 weeks after PVP-I treatment by MTT and deposited calcium using an Alizarin-red staining test.
  
  
  RESULTS
  PVP-I decreased ALP activity substantially. Stimulation by BMP-2 recovered ALP activity to near control levels at 1:100 and 1:1000 dilutions of PVP-I. The MTT assay showed reduced proliferation of the preosteoblastic cells for all treatments, irrespective whether BMP-2 was used or not. Only at PVP-I dilutions of 1:1000 proliferation rate was back to normal levels (95.6±2.4 %). No adverse long-term effect of PVP-I on mineralization of the extracellular matrix (Alizarinred) for dilutions higher than 1:100 was observed. Interestingly, undiluted and 1:10 diluted PVP-I even showed a significant increase in mineral deposition, especially in the presence of BMP-2.
  
  
  CONCLUSIONS
  Short-time application of PVP-I in concentrations of 1:10 and higher lead to decreased viability and impaired differentiation. However, surviving cells showed good recovery and mineralization potential.
authors.affiliation: Clinic for Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zürich, Switzerland.
authors.forename: P R
authors.initials: PR
authors.lastname: Schmidlin
authors.forename: T
authors.initials: T
authors.lastname: Imfeld
authors.forename: P
authors.initials: P
authors.lastname: Sahrmann
authors.forename: A
authors.initials: A
authors.lastname: Tchouboukov
authors.forename: F E
authors.initials: FE
authors.lastname: Weber