The influence of erbium:yttrium-aluminum-garnet laser ablation with variable pulse width on morphology and microleakage of composite restorations.
The objective of this study was to evaluate the influence of various pulse widths with different energy parameters of erbium:yttrium-aluminum-garnet (Er:YAG) laser (2.94 mum) on the morphology and microleakage of cavities restored with composite resin. Identically sized class V cavities were prepared on the buccal surfaces of 54 bovine teeth by high-speed drill (n = 6, control, group 1) and prepared by Er:YAG laser (Fidelis 320A, Fotona, Slovenia) with irradiation parameters of 350 mJ/ 4 Hz or 400 mJ/2 Hz and pulse width: group 2, very short pulse (VSP); group 3, short pulse (SP); group 4, long pulse (LP); group 5, very long pulse (VLP). All cavities were filled with composite resin (Z-250-3 M), stored at 37 degrees C in distilled water, polished after 24 h, and thermally stressed (700 cycles/5-55 degrees C). The teeth were impermeabilized, immersed in 50% silver nitrate solution for 8 h, sectioned longitudinally, and exposed to Photoflood light for 10 min to reveal the stain. The leakage was evaluated under stereomicroscope by three different examiners, in a double-blind fashion, and scored (0-3). The results were analyzed by Kruskal-Wallis test (P > 0.05) and showed that there was no significant differences between the groups tested. Under scanning electron microscopy (SEM) the morphology of the cavities prepared by laser showed irregular enamel margins and dentin internal walls, and a more conservative pattern than that of conventional cavities. The different power settings and pulse widths of Er:YAG laser in cavity preparation had no influence on microleakage of composite resin restorations.
School of Dentistry and Special Laboratory of Lasers in Dentistry (LELO), Universidade Camilo Castelo Branco (UNICASTELO) and University of São Paulo, School of Dentistry (FOUSP), São Paulo, Brazil. ricardosnavarro@gmail.com
Ricardo Scarparo
RS
Navarro
Sheila
S
Gouw-Soares
Alessandra
A
Cassoni
Patricia
P
Haypek
Denise Maria
DM
Zezell
Carlos
C
de Paula Eduardo
D000818:Animals; D002417:Cattle; D003188:Composite Resins; D003737:Dental Cavity Preparation / Q000379:methods*; D003743:Dental Enamel / Q000528:radiation effects / Q000648:ultrastructure; D003763:Dental Leakage / Q000517:prevention & control; D003793:Dental Restoration, Permanent / Q000379:methods; D003804:Dentin / Q000528:radiation effects / Q000648:ultrastructure; D066298:In Vitro Techniques; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D028022:Low-Level Light Therapy / Q000379:methods*; D008855:Microscopy, Electron, Scanning
D003188:Composite Resins