title: Controlled release of metronidazole from composite poly-ε-caprolactone/alginate (PCL/alginate) rings for dental implants.
abstract: OBJECTIVE
  Dental implants provide support for dental crowns and bridges by serving as abutments for the replacement of missing teeth. To prevent bacterial accumulation and growth at the site of implantation, solutions such as systemic antibiotics and localized delivery of bactericidal agents are often employed. The objective of this study was to demonstrate a novel method of controlled localized delivery of antibacterial agents to an implant site using a biodegradable custom fabricated ring.
  
  
  METHODS
  The study involved incorporating a model antibacterial agent (metronidazole) into custom designed poly-ε-caprolactone/alginate (PCL/alginate) composite rings to produce the intended controlled release profile. The rings can be designed to fit around the body of any root form dental implants of various diameters, shapes and sizes.
  
  
  RESULTS
  In vitro release studies indicate that pure (100%) alginate rings exhibited an expected burst release of metronidazole in the first few hours, whereas Alginate/PCL composite rings produced a medium burst release followed by a sustained release for a period greater than 4 weeks. By varying the PCL/alginate weight ratios, we have shown that we can control the amount of antibacterial agents released to provide the minimal inhibitory concentration (MIC) needed for adequate protection. The fabricated composite rings have achieved a 50% antibacterial agent release profile over the first 48 h and the remaining amount slowly released over the remainder of the study period. The PCL/alginate agent release characteristic fits the Ritger-Peppas model indicating a diffusion-based mechanism during the 30-day study period.
  
  
  CONCLUSIONS
  The developed system demonstrates a controllable drug release profile and the potential for the ring to inhibit bacterial biofilm growth for the prevention of diseases such as peri-implantitis resulting from bacterial infection at the implant site.
authors.affiliation: Bioengineering Center, University of Oklahoma, Norman, OK 73019, USA.
authors.forename: Shih-Feng
authors.initials: SF
authors.lastname: Lan
authors.forename: Timilehin
authors.initials: T
authors.lastname: Kehinde
authors.forename: Xiangming
authors.initials: X
authors.lastname: Zhang
authors.forename: Sharukh
authors.initials: S
authors.lastname: Khajotia
authors.forename: David W
authors.initials: DW
authors.lastname: Schmidtke
authors.forename: Binil
authors.initials: B
authors.lastname: Starly
mesh_terms: D020341:Absorbable Implants; D000464:Alginates / Q000737:chemistry*; D000890:Anti-Infective Agents / Q000008:administration & dosage* / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry; D003692:Delayed-Action Preparations; D015921:Dental Implants; D004058:Diffusion; D016503:Drug Delivery Systems / Q000295:instrumentation; D055119:Elastic Modulus; D004548:Elasticity; D004867:Equipment Design; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006801:Humans; D020100:Hydrogels / Q000737:chemistry; D008795:Metronidazole / Q000008:administration & dosage* / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D011091:Polyesters / Q000737:chemistry*; D013314:Stress, Mechanical; D013997:Time Factors
chemical_list: D000464:Alginates; D000890:Anti-Infective Agents; D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D015921:Dental Implants; D006603:Hexuronic Acids; D020100:Hydrogels; D011091:Polyesters; D008795:Metronidazole; C016240:polycaprolactone; D020723:Glucuronic Acid