Sealing Capacity of Different Materials used as Cervical Barrier during Internal Walking Bleaching Technique

Objectives: This study evaluated the sealing ability of different temporary restorative materials used as a barrier in the passage of oxygen generated during internal bleaching technique mediated by different time intervals. Material and methods: 30 bovine teeth stored in thymol solution 0.1%, were prepared, sealed and randomly assigned into 3 groups (n = 10), in accordance with the sealing material: Riva Self Cure (RIV), Bioplic (BIO), and Coltosol (COL). The teeth were submitted to bleaching using walking bleach technique (Whiteness perborate), then were fixed with composite (Filtek Z350 XT, 3M ESPE) in a number 7 orthodontic wire and adopted in a plastic container so that only 2mm below the amelocementary junction would stay submerged in distilled water. The samples were analyzed by an oximeter (Digimed) for measuring oxygen release after 7, 14, 21 and 28 days, always maintaining samples stored in a laboratory incubator at 37oC. The data was submitted to 2-way ANOVA and Turkey test (p = 0.05). Results: Both material (p = 0.0154) and time (p <0.000) had an effect on the result of oxygen level. Over all Bioplic showed the highest and Riva the lowest ability, while Coltosol presented intermediate results. All materials showed lower levels of oxygen release within the first 7 days. From 14 to 28 days, there was no statistically significant increase in the release of oxygen. Conclusion: All materials seemed to present the best sealing performance within the first 7 days. The highest ability of sealing capacity was shown by Bioplic.