Details

Autor(en) / Beteiligte

• de Souza-Zaroni, W. C.
• Freitas, A. C. P.
• Hanashiro, F. S.
• Steiner-Oliveira, C.
• Nobre-dos-Santos, M.
• Youssef, M. N.

Titel

Caries resistance of lased human root surface with 10.6 μm CO2 laser-thermal, morphological, and microhardness analysis

Ist Teil von

• Laser physics, 2010-02, Vol.20 (2), p.537-543

Ort / Verlag

Dordrecht: SP MAIK Nauka/Interperiodica

Erscheinungsjahr

2010

Beschreibungen/Notizen

• Although the cariostatic effects of CO 2 laser on enamel have been shown, its effects on root surface demineralization remains uncertain. The objectives of this in vitro research was to establish safe parameters for a pulsed 10.6 μm CO 2 laser and to evaluate its effect on morphological features of the root surface, as well as on the reduction of root demineralization. Ninety-five human root surfaces were randomly divided into five groups: G1-No treatment (control); G2—2.5 J/cm 2 ; G3—4.0 J/cm 2 ; G4—5.0 J/cm 2 ; and G5—6.0 J/cm 2 . Intrapulpal temperature was evaluated during root surface irradiation by a thermocouple and morphological changes were evaluated by SEM. After the surface treatment, the specimens were submitted to a 7-day pH-cycling model. Subsequently, the cross-sectional Knoop microhardness values were measured. For all irradiated groups, intrapulpal temperature changes were less than 1.5°C. Scanning electron microscopy images indicated that fluences as low as 4.0 J/cm 2 were sufficient to induce morphological changes in the root surface. Additionally, for fluences reaching or exceeding 4.0 J/cm 2 , laser-induced inhibitory effects on root surface demineralization were observed. It was concluded that laser energy density in the range of 4.0 to 6.0 J/cm 2 could be applied to a dental root to reduce demineralization of this surface without compromising pulp vitality.