TEMPERATURE INCREASE DURING REMOVAL OF INCISAL EXTENSIONS ON RESIN-BONDED CASTINGS

To assist seating or relocation of resin-bonded retainers on abutments , extensions of the cast framework can be incorporated and removed aft er cementation. There has been apprehension concerning the heat create d during the grinding of these extensions, particularly if there is a substantial bulk of metal. This study recorded the elevation of temper ature when cast incisal extensions were removed by grinding after ceme ntation. A total of 20 retainers were waxed for 0.3mm thickness, cast in a nickel-chrome alloy, and bonded in-vitro to an acid-etched natura l tooth with composite resin cement. The temperature of the coronal de ntin was measured while the tag was ground with a high-speed dental ha ndpiece. The maximum temperature and mean temperature elevations that exceeded the resting temperature were recorded. A significant temperat ure rise was apparent when complete incisal wrapover framework extensi ons were reduced compared with the removal of fingerlike locating exte nsions. in conclusion, care should be exercised when the locating exte nsions of resin-bonded retainers are removed with highspeed dental han dpieces.