[Scanning electron microscopy was used to observe dentin morphology in primary and permanent teeth treated by erbium: yttrium-aluminum-garnet laser].

OBJECTIVE

To observe the morphological change of cavities in teeth prepared using the erbium: yttrium-aluminum-garnet (Er:YAG) laser with different parameters.

METHODS

Ten extracted cavity-free molars were divided into control group and experiment group. The control group included 2 permanent teeth and 2 primary teeth. The experiment group was divided into 3 groups according to the different laser parameters. Group 1 included 2 permanent teeth, while group 2 and group 3 included 2 primary teeth respectively. Cavities were prepared using traditional handpieces in the control group or the Er: YAG laser with different parameters in the experiment group (group 1: Er:YAG laser 20 Hz/200 mJ,group 2: Er:YAG laser 10 Hz/300 mJ,group 3: Er:YAG laser 10 Hz/400 mJ) .The samples were made for Scanning Electron Microscopy(SEM) analysis.

RESULTS

The dentin surface of cavities using Er:YAG laser showed no formation of smear layer and open dentinal tubules. Dentin melting was not detected after preparation of groups 1 and 2. There were cracks and micro-fissures in the dentin surface of the primary teeth prepared using Er:YAG laser 10 Hz/400 mJ.

CONCLUSION

Appropriate Er:YAG laser parameters(groups1 and 2) were effective and safe for ablation of hard tissue of primary and permanent teeth. The high power Er: YAG laser 10 Hz/400 mJ would damage the dentin surface when used in primary teeth.