A development of antiplaque composite resin by chemically binding Dextranase

1991 Fiscal Year Final Research Report Summary

• Project/Area Number: 02670851
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Conservative dentistry
• Research Institution: Osaka University
• Principal Investigator: YASUNAGA Tetsuya Osaka University, Dentistry Instructer, 歯学部, 助手 (70182342)
• Co-Investigator(Kenkyū-buntansha): KAWAI Keiji Osaka University, Dentistry Assistant Professor, 歯学部附属病院, 講師 (40204664) ; TSUCHITANI Yasuhiko Osaka University, Dentistry Professor, 歯科部, 教授 (40028709)
• Project Period (FY): 1990 – 1991
• Keywords: Dextranase / Antiplaque Activity / Immobilized Enzyme / Water Insoluble Glucan

Research Abstract

The experimental resin was prepared : Bis-GMA 55.3%, TEGDMA 27.6%, polyacrylic acid 16.6%, BPO 0.5%. This resin was polymerized for 24 h at 60ﾟC and 4 h at 100ﾟC. The discs of this resin(10mm in diameter and 1mm thickness)were prepared and stored in 0.1M-potassium phosphate buffer solution(pH6.0). Dextranase was bonded to the disc by the following procedure. One disc and N-ethyl-5-phenylisoxazolium3'-sulfonate(40mg)were stirred for 1 h at 4ﾟC in 10ml of 0.1M-potassium phosphate buffer(pH6.0). Dextranase(40units)were then added, and the reaction mixture stirred for 24 h at 4ﾟC. 0.11 units of dextranase activity was found on a disc.
The effect of dextranase bound resin on the glucosyltransferase of Streptococcus mutans was investigated. Specimens of seven materials were prepared : 1. the dextranase bound experimental resin, the untreated experimental resin, Unifast, Fuji Ionomer TypeII, Photoclearfil Bright, Silux Plus, Palfique Estelite. Water insoluble glucan synthesizd by glucosyltransferase on the specimens were measured. The dextranase bound resin specimen inhibited water insoluble glucan synthesis more strongly than the another specimens. The percent inhibition of water insoluble glucan formation by glucosyltransferase on the dextranase bound resin specimen was about 30% of the untreated resin specimen.
We thus examined the adherent ability of Streptococcus mutans MT6R and glucan production by this organism on the dextranase bound experimental resin. Scaning electron microscope was utilized to make this examination. The dextranase bound experimental resin inhibited the adherence of Streptococcus mutans more strongly than the untreated experimental resin.
From this investigation it was concluded that this dextranase bound experimental resin have antiplaque activity.