The sustaining effect of three polymers on the release of chlorhexidine from a controlled release drug device for root canal disinfection

Abstract

ABSTRACT Ⅰ. Introduction Complete debridement and thorough disinfection ofinfected root canals are considered mandatory for thesuccess of root canal treatment 1) . However, canalpreparation and irrigation are not always effective ineliminating total microflora from the root canal sys-tem 1-3) . Traditionally, calcium hydroxide has provento be an excellent intracanal medicament for infectedroot canals 4,5) . However, it is known to be less effec-tive against the therapy-resistant flora such likeEnterococcus facecalis, Actinomycesand Candidathat are frequently isolated in persistent root canals 6) .This is because of dilution of calcium hydroxide astime passes or dentin buffering effects 7) . Therefore,alternative medicaments should be explored thatwould maximize microbial eradication when used asintracanal disinfection. Intracanal disinfection of infected root canal is one of important treatment procedure. This in vitrostudyaimed to evaluate whether the surface polymers of controlled release drug (CRD) can effectively control therelease rate of chlorhexidine for root canal disinfection. Four CRD prototypes were prepared: Group A(n=12); The core device (absorbent paper point) was loaded with 40% CHX solution as control. Group B(n=12); same as group A, but the device was coated with chitosa n. Group C (n=12); same as group Aand then coated three times with 5% PMMA. Group D (n=12); same as group A and then coated threetimes with 3% PLGA. All CRD prototypes were soaked in 3 mL dist illed water for experimental periodsand the concentrations of released CHX from each CRD prototype were determined using a UV spectropho-tometer. Results showed that release rate of CHX were the greatest in the non-coated group (controlgroup), followed by the chitosan-coated group, the PLGA-coated group, and the PMMA-coated group (P <0.05). This data indicate that surface polymers can control the release rate of CHX from the CRD proto-types.