Influence of various polishing methods on pulp temperature : an in vitro study.

OBJECTIVE

After orthodontic debonding, adhesive removal can lead to rises in pulp temperature, causing histological changes or pulp necrosis. The objective of this study was to measure increases in pulp temperature during adhesive removal using different instruments and various cooling procedures.

MATERIALS AND METHODS

A thermoelement was introduced into the pulp chamber of 10 human incisors. The teeth were immersed in a 36°C water bath up to the cementoenamel junction. Two carbide burs, one polishing disk and two rubber points were used for polishing. All measurements were taken over a 10 s period by a single investigator, under slight pressure and with constant motion. Three cooling procedures were examined: no cooling, air cooling and water cooling. Pulp temperatures were measured before polishing and after 10 s of polishing.

RESULTS

Without cooling, the two rubber points revealed clinically relevant temperature increases of 6.1°C and 12.4°C. Cooling with air and with water reduced pulp temperature in conjunction with all polishing methods. Air cooling was most efficient, except in combination with the polishing disk.

CONCLUSION

Under these study conditions, carbide burs and polishing disks can be used safely and without risk to the pulp, even without cooling. On the other hand, rubber points cause a marked increase in pulp temperature when used without cooling.