| Objective:This test chose four polish means, evaluated the RBS, recorded the time and observed enamel pattern. Finally finding an optimum means which damaged enamel least, time-consuming shortest and got the strongest RBS.Materials and Methods:We choose the metal standard straight wire brackets with etching base, gluma acid etching, and adhesive resin of orthodontic non-tone-based chemical curing adhesive mixing, artificial saliva, universal force measure, and SEM(Scanning Electron Microscope). Four tooth polishing means were dia-bur at high speed, silicon particles at low speed, bondage removing pliers and ultrasonic-sandblasting. One hundred and fifty young extracted maxillary first premolars were randomly distributed among four experimental groups and one control. Then each group was divided into two secondary groups (group A and group B). All groups A were brought to evaluate the RBS or SBS and all groups B were brought to observe the enamel pattern. We bonded the brackets according to the adhesive illuminate. After 24 hours we measured SBS of control group A. Others were debonded by bracket removing pliers, polished the enamel and recorded the time consuming, bonded the new brackets again. Then measured the RBS, observed enamel pattern by SEM, and scored ARI and ESI. Finally doing the statistical treatment by SPSS 13.0, using one-way ANOVA and LSD to analyze significant differences between SBS and RBS, and analyze the effects of different means for tooth surface polishing on brackets' RBS. Sum of ranks were used to determine ARI and ESI scores. Result:(1) The average of SBS of brackets is 14.72Pa, and the average of RBS respectively is 18.32Pa(dia-bur),14.73Pa(silicon particles),16.05Pa(bondage removing pliers) and 17.11Pa(ultrasonic-sandblasting). The data of group of dia-bur, bondage removing pliers and ultrasonic-sandblasting greater than control group obviously, and differences has statistically significance (P≤0.05). We were not observed statistically significant differences (P>0.05) between the group of control and silicon particles. (2) Ordering time-consuming on polishing teeth was that dia-bur (6.42s)<bondage removing pliers (32.59s)<ultrasonic-sandblasting (46.55s)< silicon particles (58.35s), and the differences between every two groups has statistically significance (P≤0.05). (3) ESI scores of dia-bur were greatest (28 points), and the silicon particle was lowest (10 points). Statistically significant differences (P≤0.05) between this and the other group were observed. (4) ARI scores was ordered growing that dia-bur (23 points)< ultrasonic-sandblasting (24 points)< silicon particles (29 points)<bondage removing pliers (34 points). Among these, significant differences (P≤0.05) between bondage removing pliers and dia-bur, ultrasonic-sandblasting were observed. (5) The morphologies of enamel after polishing by SEM were significant differences.Conclusion:(1) The effect of secondary shear bond strength is optimal, meeting the clinical needs. (2) Using dia-bur to polish remnant resin, the efficiency is highest while easily damage the enamel; using silicon particles can protect enamel while the efficiency is lowest; using ultrasonic-sandblasting can broke enamel more or less and using bondage removing pliers is not good enough, still seeing resin residue. So we can use these together in the clinical practice in according with the thickness and quality of resin. |
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