수분의 양에 따른 두 단계 산부식 접착제의 상변화

Abstract

The objective of this study was to investigate on phase change of two step total etching system by water. Three commercial two-step total etching adhesives-OptiBond Solo Plus (OPB), Single Bond Plus(SB) and Excite(EX) were used. Three adhesives were mixed with 1, 2, 3, 4 and 5 ㎕ distilled water(d/w) respectively. Control group was not mixed with d/w. After mixing(10s) and air-drying(30s), these samples were observed under light microscope(LM) for examination of phase change. 10 consecutive drops of adhesives were deposited on slide glass. Images were captured immediately after deposition with Standard goniometer(ramé-hartinstrumentco.,Netcong,USA). The DROPimage Advanced software(ramé-hartinstrumentco.,Netcong,USA) provided the value of contact angle. The amount of volatile part in adhesives was determined by a precision balance(OHAUS Co., 19A Chapin Road, Pine Brook, NJ 07058 USA). In LM examination, OPB and Ex were observed with phase changes, but SB was not. The contact angles of OPB and Ex were higher than SB. There were no significant differences among these three experimental groups. Due to hydrophobicity of OPB and EX, they showed the phase change in less wet condition. In conclusion, OptiBond Solo Plus and Excite are expected to be more sensitive to over-wet condition in wet bonding technique.