title: The sustaining effect of three polymers on the release of chlorhexidine from a controlled release drug device for root canal disinfection.
abstract: OBJECTIVE
  The aim of this in vitro study was to evaluate the suitability of using chitosan, poly (lactide-co-glycolide) (PLGA), and polymethyl methacrylate (PMMA) to control the release of chlorhexidine digluconate (CHX) from a prototype of controlled release drug device for root canal disinfection.
  
  
  METHODS
  Four different prototypes with different formulations were prepared. Group A (n = 12): the device (absorbent paper point) was loaded with CHX as control. Group B (n = 12): same as group A, but the device was coated with chitosan (Texan MedTech). In Groups C and D, the device was treated in the same way as group A and then coated 3 times with 5% PMMA (Group C, n = 12, Aldrich), or coated 3 times with 3% PLGA (Group D, n = 12, Sigma). The devices were randomly allocated to experimental groups of 12 each. All the prototypes of controlled release drug device were soaked in 3 mL distilled water. The concentrations of CHX were determined using a UV spectrophotometer. The surface characteristics of each prototype were observed using a scanning electron microscope.
  
  
  RESULTS
  The result showed that release rate of CHX was the greatest in the noncoated group, followed by the chitosan-coated group, the PLGA-coated group, and the PMMA-coated group (P < 0.05). Pores were observed on the surface of the prototypes that were coated with PLGA and PMMA. When the pore size was smaller, the release rate was lower.
  
  
  CONCLUSIONS
  These data indicate that polymer coating can control the release rate of CHX from the prototypes of controlled release drug device.
authors.affiliation: Department and Research, Institute of Dental Biomaterials and Bioengineering, College of Dentistry, Yonsei University, Seoul, South Korea.
authors.forename: Doug-Youn
authors.initials: DY
authors.lastname: Lee
authors.forename: Larz S W
authors.initials: LS
authors.lastname: Spångberg
authors.forename: Young-Bin
authors.initials: YB
authors.lastname: Bok
authors.forename: Chang-Young
authors.initials: CY
authors.lastname: Lee
authors.forename: Kee-Yeon
authors.initials: KY
authors.lastname: Kum
mesh_terms: D000704:Analysis of Variance; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage*; D048271:Chitosan; D002710:Chlorhexidine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D020099:Coated Materials, Biocompatible; D003692:Delayed-Action Preparations; D019344:Lactic Acid; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D019904:Polymethyl Methacrylate; D016062:Porosity; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D013056:Spectrophotometry, Ultraviolet; D013499:Surface Properties
chemical_list: D000891:Anti-Infective Agents, Local; D020099:Coated Materials, Biocompatible; D003692:Delayed-Action Preparations; D011108:Polymers; D012388:Root Canal Irrigants; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D019904:Polymethyl Methacrylate; D048271:Chitosan; C010882:chlorhexidine gluconate; D002710:Chlorhexidine