Intrapupal temperature variation during Er,Cr: YSGG enamel irradiation on carries prevention

Abstract

Studies have shown the cariostatic effect of Er,Cr:YSGG (2.78 μm) laser irradiation on human enamel and have suggested its use on caries prevention. However there are still no reports on the intrapulpal temperature increase during enamel irradiation using parameters for caries prevention. The aim of this in vitro study was to evaluate the temperature variation in the pulp chamber during human enamel irradiation with Er,Cr:YSGG laser at different energy densities. Fifteen enamel blocks obtained from third molars (3 x 3 x 3 mm) were randomly assigned to 3 groups (n=5): G1 – Er,Cr:YSGG laser 0.25 W, 20 Hz, 2.84 J/cm2, G2 – Er,Cr:YSGG laser 0.50 W, 20 Hz, 5.68 J/cm2, G3 – Er,Cr:YSGG laser 0.75 W, 20 Hz, 8.52 J/cm2. During enamel irradiation, two thermocouples were fixed in the inner surface of the specimens and a thermal conducting paste was used. One-way ANOVA did not show statistically significant difference among the experimental groups (α=0.05). There was intrapulpal temperature variation ≤0.1°C for all irradiation parameters. In conclusion, under the tested conditions, the use of Er,Cr:YSGG laser with parameters set for caries prevention lead to an acceptable temperature increase in the pulp chamber.

Laser‐assisted pulpotomy in primary teeth: a systematic review

“…Pulpal ablation through successive laser application resulting in pulp stumps free of haemorrhage, might raise hyperaemia of the residual pulp tissue, in turn potentially influencing the treatment outcome. In this context, potential thermal damage may be prevented using copious water irrigation during laser application or by reducing either or both the power emitted, pulse frequency, or total application time . Additional research is needed to determine the appropriate settings for treatment of pulpally involved human teeth.…”

Erbium Lasers for the Prevention of Enamel and Dentin Demineralization: A Literature Review

“…69 The increase of the pulp chamber temperature was evaluated during Er,Cr:YSGG laser irradiation with subablative parameters without water cooling (energy density up to 8.5 J/cm 2 ) in two studies using thermocouples. 29,69 In the first study, the temperature was recorded at a sampling rate of 20 Hz and in the second, the temperature was captured every 2 sec. The results of both studies indicated that intrapulpal temperature increased below the threshold for pulp damages.…”

“…Several studies have already described the effect of laser-induced prevention of demineralization (LIPD) with different wavelengths. [26][27][28][29][30][31] For an effective laser treatment, optimal interactions between the laser light and tissue must occur. The laser interaction with dental hard tissues depends on irradiation parameters such as wavelength, pulsed or continuous emission, pulse duration, energy, frequency, spot size, delivery method, laser beam features, and optical properties of tissue such as the refractive index, scattering coefficient (ls), and absorption coefficient (la).…”

Aderência bacteriana à superfície de esmalte dental irradiado por lasers com parâmetros para prevenção de cárie

“…Os lasers de alta potência apresentam efeitos térmicos que podem promover alterações morfológicas na estrutura dental, como redução da permeabilidade, fusão e ressolidificação, criação de microespaços na estrutura mineral do dente (MORIOKA; TAGOMORI; OHO, 1991;MORIOKA, 1989), bem como alterações químicas que podem estar relacionadas com o aumento da resistência ácida do esmalte (FEATHERSTONE, 2000b;KURODA, 1986;FREITAS et al, 2008;HOSSAIN et al, 1999a;HOSSAIN et al, 1999b), sendo observadas alterações nas características cristalográficas dos cristais de hidroxiapatita, redução do conteúdo de carbonato (CO 3 ), conversão do fosfato (HPO 4 2-) em pirofosfato(P 2 O 7 4-), aumento da concentração de íons hidroxila (OH-), decomposição protéica resultando na redução da solubilidade mineral, ressolidificação, crescimento dos cristais e formação de novos compostos cristalinos (CECCHINI et al, 2005;HSU et al, 1994). Observa-se que à medida que a irradiação com os lasers de alta potência é realizada, alterações físico-químicas acontecem gradualmente com o aumento da temperatura (BEVILACQUA et al, 2008;CASTELLAN et al, 2007;LIU;LIU;STEPHEN, 2006 KURODA, 1986).…”

“…Alguns lasers de alta potência têm apresentado um potencial para prevenção de cárie através de alterações morfológicas e/ou químicas, como os lasers de Er:YAG (2,94 µm) (APEL et al, 2004;APEL et al, 2005;FREITAS et al, 2008;HOSSAIN et al, 2001;HOSSAIN et al, 1999b), Er,Cr:YSGG (2,78 μm) HOSSAIN et al, 1999b), Nd:YAG (1.064 nm) (BOARI; ZEZELL; EDUARDO, 1999) e CO 2 (9.6 e 10.6 μm) KLEIN et al, 2005; (BEVILACQUA et al, 2008). Considerando o fato de o laser de érbio ter sido introduzido na odontologia para preparo do tecido dental mineralizado, a sua utilização para prevenção de cáries requer algumas alterações, como a utilização de densidades de energia sub-ablativas, visto que a intenção não é ablacionar ou provocar fusão do substrato, mas sim a de gerar mudanças químicas (APEL et al, 2005).…”