RESUMEN
BACKGROUND: Plenty of studies have already proved the effective usage of epigallocatechin gallate (EGCG) in clinical treatment. However, no current research has focused on the application of EGCG in preventing white spot lesions (WSLs) during orthodontics treatment with fixed appliances. OBJECTIVE: To study the value of EGCG in the prevention of WSLs during orthodontic treatment with fixed appliances. METHODS: In total 50 patients undergoing orthodontic treatment with fixed appliances were carefully screened and enrolled. Split-mouth design was adopted: the right side of teeth received experimental adhesive (1 g/L EGCG + Adper™ Single Bond 2); the left side of teeth acted as control. All the other clinical procedures and materials used were same. The enamel demineralization index (EDI) and the WSLs prevalence of targeted teeth (16, 11, 46, 26, 31, and 36) were detected at 3, 6, and 12 months during the treatment, and the percentage of bracket bonding failure was calculated for each group. The study protocol was implemented in line with the relevant ethical requirements of Liuzhou People’s Hospital. Patients and their guardians were fully informed of the whole trial procedures. RESULTS AND CONCLUSION: In this trial, the percentage of bracket bonding failure was significantly different between the EGCG group and control group (P > 0.05). After 3 months of treatment, the values of WSLs and EDI had no significant difference between the EGCG group and control group (P > 0.05). However, after 6 months and 12 months treatment, the EGCG group manifested significantly lower WSL and EDI values than the control group (P < 0.05). Therefore, addition of the adhesive containing 1 g/L EGCG has a considerable effect in preventing enamel demineralization and the occurrence of WSLs without influencing the enamel bonding strength, and it has a long-time effect which deserves the clinical expansion.
RESUMEN
OBJECTIVE: To evaluate shear bond strength of 3 adhesive systems (Single Bond, TransbondTM MIP and TransbondTM XT) applied on bovine enamel under saliva contamination condition. METHOD: One hundred and twenty enamel surfaces of bovine incisors were divided into 6 groups (n = 20) according to the adhesive system used (TransbondTM XT, TransbondTM MIP and Single Bond) with or without saliva contamination. For each adhesive system, there were two groups defined as no contamination group (NC): 37% H3PO4 conditioning for 30 seconds and two layers of adhesive systems; saliva contamination group (SC): After the first adhesive layer application, the examined areas were contaminated with saliva. Samples were mounted appropriately for testing and stored in deionized water at 37 ºC for 7 days. Samples were then submitted to shear bond strength trials at a speed of 0.5 mm/min. The Adhesive Remnant Index (ARI) was evaluated under stereomicroscopy. Two-way analysis of variance and the Tukey test were used to compare mean values (α = 0.05). RESULTS: Groups XT (NC) = 26.29 ± 7.23; MIP (NC) = 24.47 ± 7.52 and SB (NC) = 32.36 ± 4.14 XT (SC) = 19.59 ± 6.76; MIP (SC) = 18.08 ± 6.39 and SB (SC) = 18.18 ± 7.03 MPa. ARI 0 and 1 were the most prevalent scores in all study groups examined. CONCLUSION: Saliva contamination significantly decreased bond strength of the three adhesive systems examined (p <0.05). However, the comparison of groups with and without saliva contamination did not reveal any significant differences, and, therefore, the three systems may be considered equivalent.