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Dental fluorosis (dental fluorosis) clinical symptoms as the enamel appears on chalk color to brown patches, severe cases may be complicated by the enamel of substantive defect, affecting the patient's facial appearance. Commonly veneer is an ideal repair method to improve dental fluorosis color, it will repair material covering, directly or indirectly, on the surface of the teeth using bonding technology. However, due to the special structure of fluorosis enamel bonding effect is less than normal teeth which could easily lead to the shedding of veneer. Studies have shown that air abrasion (air-abrasion) technology is applicable in the present composite resin bonding repair, the treated enamel or dentin bonding with composite resin to form a more effective, has been used for caries removal, cavity preparation, repair composite materials. In this study, by shear experiments and experimental observation of microleakage air abrasion improve the bonding effect than the combined fluorine etching pretreatment of dental enamel and resin bonding agent (compositeresin cement) abrasive jet and This is the basis of confirmed air abrasion technology can be applied to the tooth surface pretreatment before dental fluorosis clinical veneer. The first part of the air abrasion mottled enamel on porcelain - enamel bond strength of purpose: in vitro evaluation of air abrasion method, etching on both pretreatment mottled enamel combined them with a ceramic block bonding strength impact. Methods: Dean's classification standard, 30 moderate lesions of dental fluorosis, were randomly divided into three groups A, B, C, mottled enamel in vitro simple etching, simple jet mill, jet mill plus acid etching, then bonding ceramic block, measured shear strength data results using ANOVA test was used for statistical analysis. Was observed under stereomicroscope bonding damage, and the shape after the enamel surface treatment was observed by scanning electron microscopy (scanningelectron microscopy, SEM) of the three groups A, B, C are used. Results: ① group B, the enamel shear strength of pure air abrasion group (11.75 ± 2.26) MPa A group that enamel shear strength of conventional etching groups (15.25 ± 2.82) MPa significantly between the two difference (P <0.05); ② Group C jet mill plus etching groups the enamel shear strength (18.77 ± 3.90) MPa, and the A group that is also a significant difference (P <0.05) between conventional etching groups. Conclusion: air abrasion and etching pretreatment mottled enamel Relay improve fluorosis tooth surface with all-ceramic restorations sticky. The second part of the jet mill processing mottled enamel on the teeth - Resin - porcelain bonding interface microleakage research purposes: In vitro evaluation of air abrasion, acid etching and a combination of the two treatment mottled enamel on the tooth - resin - porcelain sticky access the interface between microleakage. Methods: According to the Dean's classification criteria, select the first premolar extraction of 18 dental fluorosis orthodontic patients for the study were randomly divided into three groups, A, B, C (n = 6), three groups of isolated fluorosis teeth the enamel were simple etching, simply spray grinding mill plus acid etching and then spray resin adhesives for bonding ceramic blocks, all samples for a total of 500 of the hot and cold cycle, placed soaked in 1% methylene blue solution staining 24 hours. The sample along the long axis of the tooth vertical incision, observed and photographed 40 times under a stereomicroscope, measurement software to measure of teeth - resin interface and porcelain - resin interface dyes penetrate the deepest point to the bonding edge the distance as the measured values ??of microleakage variance test was used for statistical analysis. Result: pure air abrasion group dental - resin interface microleakage measured value (1.39 ± 0.33) mm, compared with conventional acid etching group (0.98 ± 0.30) mm, between the two there is a significant difference (P < 0.05); abrasive jet etching groups teeth - resin interface microleakage measured value (0.48 ± 0.24) mm, compared with conventional etching groups showed significant differences (P <0.05). Three sets of porcelain - resin interface microleakage values ??were (0.69 ± 0.40) mm, (0.81 ± 0.50) mm, (0.73 ± 0.74) mm, does not have a significant difference. Conclusion: The air abrasion plus acid etching pretreatment mottled enamel microleakage reduce mottled enamel and resin bonding agent interface, enhanced adhesion between mottled enamel bonding agent.
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