Eduardo Luiz Barbin

In vitro evaluation of the thermal alterations on the root surface during preparation with different Ni-Ti rotary instruments

The present study evaluated, in vitro, the temperature alterations on the external root surface during instrumentation with four different rotary systems. A total of 20 extracted human maxillary lateral incisors were instrumented using either the ProFile, MicroMega, Quantec or K3 systems and the thermal alterations on the root surface were recorded by means of three thermocouples attached to the coronal, middle and apical portions of the root. Mean temperature increases no higher than 0.4 degrees C +/- 1.0 degrees C (ProFile system) were recorded, which indicates that these instruments are safe for the surrounding periodontal tissues.

In vitro evaluation of external root temperature changes during Er:YAG laser application with five different fiberoptic tip withdrawl techniques

This study evaluated in vitro the external temperature increase at the three root thirds using five different fiberoptic tip withdrawal techniques in 50 human canines. Er:YAG laser was applied with a 50/28 fiberoptic tip with 250 mJ input, 112 mJ output, 10 Hz, 1 mm from the apical foramen: group 1: each third was irradiated starting at the apex for 1 s on each wall, with the irradiation turned off between thirds; group 2: apical third irradiated without movement for 2 s and tip withdrawn with continuous radiation up to the cervical third; group 3: tip activated at the apex and removed to the canal entrance in a straight line; group 4: tip activated at the apex and removed to the canal entrance with circular movements touching all walls; group 5: tip activated at the apex and removed to the canal entrance with clockwise circular movements for 6 s adn then reinserting and removing with counter-clockwise circular movements for another 6 s, touchgin all walls. Group 1 had significantly lower external temperature (p<0.01). The middle third had the greatest temperature increase (p<0.01). We conclude that the withdrawl techniques caused an increase in external root temperature that would not damage adjacent tissues.

In vitro evaluation of external root temperature changes during Er:YAG laser application with five different fiber optic tip withdrawal techniques

This study evaluated in vitro the external temperature increase at the three root thirds using five different fiber optic tip withdrawal techniques in 50 human canines. Er:YAG laser was applied with a 50/28 fiber optic tip with 250 mJ input, 112 mJ output, 10 Hz, 1 mm from the apical foramen: group 1: each third was irradiated starting at the apex for 1 s on each wall, with the irradiation turned off between thirds; group 2: apical third irradiated without movement for 2 s and tip withdrawn with continuous radiation up to the cervical third; group 3: tip activated at the apex and removed to the canal entrance in a straight line; group 4: tip activated at the apex and removed to the canal entrance with circular movements touching all walls; group 5: tip activated at the apex and removed to the canal entrance with clockwise circular movements for 6 s and then reinserting and removing with counterclockwise circular movements for another 6 s, touching all walls. Group 1 had significantly lower external temperature (p<0.01). The middle third had the greatest temperature increase (p<0.01). We conclude that the withdrawal techniques caused an increase in external root temperature that would not damage adjacent tissues.