Erbium laser ineffective for removing smear layers from mesial roots of mandibular first molars

One hundred (100) mandibular first molars were selected. Ninety-six (96) mesial roots were assigned to two experimental groups according to the laser wavelength applied: I. Er, Cr: YSGG and II. erbium-doped yttrium aluminium garnet laser system. Four samples were used as the control group. Samples of each group were distributed into two subgroups (A and B), following specific irrigation protocol. Each subgroup was divided into four subcategories according to the applied power laser. Each subcategory consisted of six samples. Teeth were observed under scanning electron microscope. The results were statistically analyzed with Kruskal–Wallis and Mann–Whitney test (SPSS statistics software).

The Results of the study are:

No statistically significant difference was observed between experimental groups I and II. However, a statistically significant difference was found among subgroups IA and IB and IIA and IIB. In every root third, groups IIA and IIB had better outcomes but it was not statistically significant. There was no statistically significant difference between the subcategories of Group I (IA1-4 and IB1-4) and Group II (IIA1-4 and IIB1-4).

Thus, the researchers concluded that the erbium laser with tested parameters did not completely remove the smear layer from the root canals. Chelating factors can contribute to the laser mechanism of smear layer removal from the apical part of narrow and curved root canals.

Reference:

Evrykleia Kourti, Ourania, Papadopoulou-Pantelidou, Kosmas Tolidis, Christos Angelopoulos, Dimitris Strakas. Laser applications in smear layer removal from posterior root canals: A comparative study. 2022.Volume25.Issue3. https://www.jcd.org.in/article.asp?issn=0972-0707;year=2022;volume=25;issue=3;spage=283;epage=287;aulast=Kourti;type=0