主催: The Japanese Society for Dental Materials and Devices
Introduction:
The success of endodontic treatment is negatively influenced by the presence of microorganisms within the root canal system. Chlorhexidine (CHX) is an antimicrobial agent under investigation as an endodontic irrigant. CHX possesses broad-spectrum antibacterial activity, biocompatibility with periodontal tissues. When CHX is used as a root canal irrigant, the antimicrobial effect is short-lived. For the long-term antimicrobial effect, the root canal system must be exposed to CHX for a longer time than that afforded by irrigation. The aim of this study was to evaluate the effect of polymer coating on the sustained release of CHX from the CHX-loaded absorbent point.
Materials and Methods:
Absorbent paper points were loaded with CHX of 20 % (w/v) by immersing and drying method. In PMMA group, the loaded absorbent points were coated 3 times with 10 % PMMA (polymethyl methacrylate) and in PBMA group, those were coated 3 times with 10 % PBMA (poly n-butylmethacrylate). The surfaces of coated absorbent points were observed by Scanning Electron Microscope (SEM). And each coated absorbent point was immersed in distilled water of 1 mL for 1, 2, 4, 8, 16, 24, 48, 72, and 96 hrs. UV absorbance at 256 nm was measured using a UV spectrophotometer to determine the concentration of released CHX.
Results and Discussion:
The result of SEM showed pores on the surface of both PBMA and PMMA groups. The pores of PBMA group were larger than those of PMMA group. Therefore, the release rate of CHX in PBMA group was higher than in PMMA group before 4 hrs. For the PMMA group, CHX was quickly released between 4 hrs and 8 hrs. Nevertheless, both of them showed sustained release of CHX, which continued for 72 hrs.
Conclusions:
The release rate of CHX from the dental absorbent paper point could be controlled by coating it with polymer. It was concluded that the dental absorbent point coated with PBMA was more effective than PMMA.
