Er: YAG laser radiation: contact versus non-contact enamel ablation and sonic-activated bulk composite placement: microleakage evaluation
Abstract
Our study aims to analyze the bond after the Er: YAG laser-radiation-prepared cavity was filled with a new kind of bulk-filled composite material. The laser radiation acted in a contact and non-contact mode.
The setting for contact ablation was as follows: energy 250 mJ/pulse with a pulse repetition rate 15 Hz, giving an average power of 3.75 W. For non-contact ablation these values were 600 mJ/pulse, 6 Hz, and 3.6 W.
Scanning ablation was provided in non-contact mode (1440 pulses/cavity) and the parameters were: energy 300 mJ/pulse, repetition rate 1 Hz, and mean power 0.3 W. Three types of laser cavities were filled with sonic activated composite resin.
Four longitudinal sections were prepared after immersion in 5% methylene blue for 24 h. Microleakage was assessed quantitatively by the degree of dye penetration; the data were analyzed by the Fisher exact test with the level of significance set at p < 0.05.
Contact and non-contact laser treatments prepared similar cavities (5167.31 versus 5356.31 mu m). Defocusing of non-contact therapy has a direct influence on the presence of dye penetration microleakage (481.19 versus 611.94 mu m).
The non-contact scan is a more effective method for laser ablation (8508.05 mu m). For that reason the dye penetration (microleakage) is higher (1458.65 mu m).
These results are statistically significant.