• Logo
  • SBMUJournals

Morphological Changes of Human Dentin after Erbium- Doped Yttrium Aluminum Garnet (Er:YAG) and Carbon Dioxide (CO2) Laser Irradiation and Acid-etch Technique: An Scanning Electron Microscopic (SEM) Evaluation

Sima Shahabi, Nasim Chiniforush, Nasrin Juybanpoor




INTRODUCTION: The aim of this study was to investigate the morphological changes of human dentin after Erbium-Doped Yttrium Aluminum Garnet (Er:YAG), Carbon Dioxide (CO2) laser-irradiation and acid-etching by means of scanning electron microscopic (SEM)

METHODS: 9 extracted human third molars were used in this study. The teeth were divided in three groups: first group, CO2 laser with power of 1.5 w and frequency of 80 Hz; second group, Er:YAG laser with output power of 1.5 W frequency of 10 Hz, very short pulse withwater and air spray was applied; and third group, samples were prepared by acid-etching 37% for 15 sec and rinsed with air-water spray for 20 sec. Then, the samples were prepared for SEM examination.

RESULTS: Melting and cracks can be observed in CO2 laser but in Er:YAG laser cleaned ablated surfaces and exposed dentinal tubules, without smear layer was seen.

CONCLUSION: It can be concluded that Er:YAG laser can be an alternative technique for surface treatment and can be considered as safe as the conventional methods. But CO2 laser has some thermal side effects which make this device unsuitable for this purpose. 


CO2 laser; Er:YAG lasers; morphological changes; SEM.


Walsh LJ . The current status of laser applications in dentistry. Aust Dent J 2003; 48: 146-55.

Goldman L, Gray JA, Goldman J, Goldman B, Meyer R. Effect of laser beam impacts on teeth Dentistry. J Am Dent Assoc 1965; 70: 601-6.

Dederich DN, Bushick RD. Lasers in dentistry. J Am Dent Assoc 2004; 135: 204-12.

Parker S. Surgical lasers and hard dental tissues. Br Dent J 2007; 202:445-54.

Nokhbatolfoghahaie H, Chiniforush N, Shahabi S, Monzavi A. SEM evaluation of tooth surface irradiated by different parameters of Er:YAG laser. J Lasers Med Sci; 2012;3(2):51-5

Shahabi S, Chiniforush N, Bahramian H, Monzavi A, Baghalian A, Kharazifard MJ. The effect of erbium family laser on tensile bond strength of composite to dentin in comparison with conventional method. Lasers in medical science; 2012 Apr 11. [Epub ahead of print].

Hibst R. Laser for Caries Removal and Cavity Preparation: State of the Art and Future Directions J Oral Laser Applications 2002; 203-12.

Lin S, Caputo AA, Eversole LR, Rizoiu L. Topographical characteristics and shear bond strength of tooth surfaces cut with a laser-powered hydrokinetic system. J of Prosthet Dent 1999; 82:451-5.

Ekworapoj P, Sidhu SK, McCabe JF. Effect of different power parameters of Er,Cr:YSGG laser on human dentine. Laser Med Sci 2007; 22:175-82.

Shahabi S, Chiniforoush N, Fekrazad R, Fatemi SM. Comparison of tensile bond strength of composite to dentine in conventional or laser prepared-cavities (Er;Cr:YSGG). J Oral Laser Applications 2010, 10:107- 10.

Schien MT, Bocangel JS, Nogueira GE, Schien PA. SEM evaluation of the interaction pattern between dentin and resin after cavity preparation using Er:YAG laser. J Dent 2003;31:127-35.

Pick RM. Using lasers in clinical dental practice. J Am Dent Assoc 1993; 124: 37-47.

Ramos ACB, Esteves-Oliveira M, Arana-Chavez VE, de Paula Eduardo C. Adhesives bonded to erbium:yttriumaluminum- garnet laser-irradiated dentin: transmission electron microscopy, scanning electron microscopy and tensile bond strength analysis. Lasers Med Sci 2008; 25: 181-9. DOI 10.1007/s10103-008-0600-0.

Botta SB, da Ana PA, Zezell DM, Powers JM, Matos AB. Adhesion after erbium, chromium: yttrium-scandiumgallium-garnet laser application at three different irradiation conditions. Laser Med Sci 2009; 24(1):67-73.

Freiberg RJ, Cozean CD. Pulsed erbium laser ablation of hard dental tissue: the effects of atomized water spray versus water surface film. Proc SPIE 2002; 4610: 74-84.

Oelgiesser D, Blasbalg J, Ben-Amar A. Cavity preparation by Er:YAG laser on pulpal temperature rise. Am J Dent 2003; 16:96-8.

Ceballos L, Toledano M, Osorio R, Tay FR, Marshal GW. Bonding to Er:YAG laser-treated dentin. J Dent Res 2002; 81: 119-22.

Freitas PM, Navarro RS, Barros JA, Eduardo CP. The use of Er:YAG laser for cavity preparation: An SEM evaluation. Microsc Res Tech 2007; 70: 803-8.

Zach L, Cohen C. Pulp response to externally applied heat. Oral Surg Oral Med Oral Pathol.1965;19:515-30.

Marracini TM, Bachmann L, Widgor HA, Walsh JT, Stabholtz, Zezell DM. Morphological evaluation of enamel and dentin irradiated with 9.6 μm and 2.94 μm Er:YAG lasers. Laser Phys 2005; 11:551-5.

Steiner-Oliveira C, Rodrigues LKA, Soares LES, Martin AA, Zezell DM, Nobre-dos-Santos M. Chemical, morphological and thermal effects of 10.6 μm CO2 laser on the inhibition of enamel demineralization. Dent Mater J 2006;25(3):455-62.

Nomelini SMB, Gabriel AES, Marchesan MA, Sousa- Neto MD, Silva-Sousa YTC. Ultrastructural analysis of radicular dentine surface submitted to CO2 laser at different parameters. Microsc Research Tech 2009; 72:737-43.

Piccione PJ. Dental laser safety. Dent Clin North Am 2004; 48: 795-807.

DOI: https://doi.org/10.22037/jlms.v4i1.3585