Abstract
The flow ratio of unpolymerized resin monomer, the thickness of the air inhibited layer and the temperature change during the polymerization process for both the auto-activated and photo-activated fissure sealants were measured. Also, several methods for removing unpolymerized resin monomer remaining of the acid etched enamel surface were evaluated.
The following results were obtained.
1. The flow ratio of unpolymerized resin monomer for the photo-activated sealants showed a significantly lower ratio than that of the auto-activated sealants.
2. The thickness of the air inhibited layer of the photo-activated sealants was significantly thinner than that of the auto-activated sealants.
3. Unpolymerized resin monomer remaining on the acid etched enamel surface was able to be removed by either acetone irrigation and scrrubing with a rotating brush, but not by water irrigation.
4. The micro structure of the acid etched enamel was preserved after removal of the unpolymerized resin monomer by means of acetone irrigation, but it was destroyed with brush scrubbing. Conclusion
1. From the standpoint of clinical utilization, the usage of photo-activated sealant is recommended.
2. The insufficiently sealed portion at pits and fissures could be supplemented by adding newly prepared resin after water irrigation and air blast dehydration.
3. When fluoride application is planed for the acid etched enamel surface where it has been covered by unpolymerized resin monomer, it is recommended that removal of resin monomer by means of a rotating brush should be prepared before the application.