ABSTRACT
BACKGROUND: The introduction of Er:YAG laser in dentistry for ablation of hard tissues advocated an alternative method of enamel etching for orthodontics purpose. MATERIALS AND METHODS: 55 extracted human third molars were inserted in acrylic resin blocks and divided into five groups of 11 teeth. Group 1 was treated with 37% orthophosphoric acid for 30 seconds. Group 2 was treated with laser irradiation (Er:YAG Fidelius III, Fotona, Slovenia) at 80 mJ and 4 Hz. Group 3 underwent laser treatment (80 mJ, 4 Hz), followed by 37% orthophosphoric acid for 30 seconds. The teeth in Group 4 were treated with laser at 40 mJ and 10 Hz. The teeth in Group 5 were treated with laser (40 mJ, 10 Hz), followed by 37% orthophosphoric acid for 30 seconds. The adhesive remnant index was determined after debonding. RESULTS: Kruskas-Wallis test showed that location parameters (median and mean) are significantly different between Groups 2 and 4 when compared with control group; on the contrary no significant difference was detected between Groups 3 and 5 with the controls. CONCLUSION: The use of Er:YAG laser alone, as in Groups 2 and 4, showed no significant advantages over phosphoric acid in the bonding procedure for orthodontics brackets.
Subject(s)
Acid Etching, Dental/methods , Dental Enamel/drug effects , Molar/drug effects , Phosphoric Acids/pharmacology , Acrylic Resins , Dental Bonding/methods , Dental Enamel/radiation effects , Humans , Lasers, Solid-State , Molar/radiation effects , Molar/surgery , Orthodontic Brackets , Tensile Strength , Tooth ExtractionABSTRACT
AIM: The aim of this study was to observe dentine and enamel surfaces of deciduous teeth under SEM after cavity preparation with Er:YAG laser using different fluences. The results showed that when using Er:YAG laser for cavity preparation in deciduous teeth, no carbonisation or cracks were observed on the enamel and dentine surfaces using energy output between 150-250 Mj, and frequency 15 Hz. The SEM images of the dentine and enamel surfaces were similar to previous studies on permanent teeth: enamel with a typical "lava flow" appearance as a result of an open core of the prism that has lost its typical hexagonal aspect and the dentine with opened tubules plus a difference in the mineral thickness between peritubular and intertubular. CONCLUSION: The difference between the SEM images of deciduous enamel and dentine when using three different energies (150-200-250 mJ) is not significant in order to recommend the use of one type of output energy. In addition, the SEM images are similar TO those of permanent teeth.
Subject(s)
Dental Enamel/ultrastructure , Dentin/ultrastructure , Laser Therapy , Microscopy, Electron, Scanning/methods , Tooth, Deciduous/ultrastructure , HumansABSTRACT
AIM: The Er:YAG laser has proven to be effective and efficient in dental hard tissue ablation. The Minimally Invasive Dentistry (MID) approach in caries removal is to stop the disease process and to restore lost tooth structure and function, maximizing the health potential of the tooth. One of the most important concepts of the MID is to preserve as much as possible the dental tissue and this approach is even more important in primary dentition where the dimensions of the crown are smaller and the dimension of the pulp chamber is bigger in relationship to the crown. After treating 30 children's teeth (primary molars and first permanent molars) with the Er:YAG laser, we come to conclusion that laser treatment possesses the requirements of Minimal Invasive Dentistry: the possibility to ablate small area of infected layer guarantees maximum conservation of the tooth structure; using the antibacterial property of the Er:YAG laser we can decontaminate the affected layer that retains its remineralising potential; the lack of smear layer after vaporization with laser assures a better retention of the composite resin to the dentine; preparing the enamel surface with laser before etching gives a better marginal seal of the composite restoration.
