Morpho-structural aspects of Er:YAG-prepared class V cavities

• Published in: Journal of clinical laser medicine & surgery Vol. 22; no. 2; p. 119
• Main Authors: Curti, Manlio, Rocca, Jean-Paul, Bertrand, Marie-France, Nammour, Samir
• Format: Journal Article
• Language: English
• Published: United States 01.04.2004
• Subjects: Dental Cavity Preparation - methods; Dental Enamel - pathology; Dentin - pathology; Humans; In Vitro Techniques; Laser Therapy; Molar, Third - pathology
• ISSN: 1044-5471
• DOI: 10.1089/104454704774076172

The aim of this study was to evaluate the ability of an Er:YAG laser (2960nm) to prepare class V cavities as compared with rotary instruments. Twenty-six freshly extracted human molars were selected and randomly distributed in two groups. Non standardized class V cavities were prepared using (group 1) a diamond bur for enamel, plus a tungsten bur for dentin with water irrigation and (group 2) an Er:YAG laser (output parameters, enamel: 1000 mJ, 12Hz, dentin: 500 mJ, 20Hz) with a continuous flow of water. The SEM examination revealed characteristic micro-irregularities of the lased samples as compared with the conventional prepared cavities: group 1, the walls of the cavities were slightly curved and a smear layer plus muds covered peripheric walls as well as the depth of the cavity; rare dentinal tubules were opened; linear and circular surface irregularities were observed on the dentin; and group 2, the walls of the cavities were irregular, jagged; photo-ablation creates a real cleavage of hydroxyapatite prisms with respect to the enamel prism pathway; an homogeneous dentin with opened dentinal tubules covered the depth of the cavities; intertubular dentin is selectively more ablated than Er-YAG the peritubular dentin. Jagged outline as well as opened dentinal tubules are the main characteristics of the Er-YAG prepared class V cavities. Further investigations (ulstrastructural, histochemical properties of the lased dentin, resistance to traction of bonded resins) should be conducted.