Comparison between two methods for resin removing after bracket debonding

Structural and Color Alterations of Teeth following Orthodontic Debonding: A Systematic Review

AIM

The objective of this study was to explore the effects of fixed orthodontic appliances on enamel structure by assessing microfractures, surface roughness, and alterations in color.

METHODS

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A systematic search of online databases was conducted using the keywords 'enamel' AND 'orthodontic debonding'. Eligibility criteria included both in vivo and ex vivo clinical trials conducted on human teeth.

RESULTS AND DISCUSSION

A total of 14 relevant papers were analyzed. Various instruments and techniques were utilized across different studies to assess surface roughness, color change, and surface fractures.

CONCLUSIONS

The findings of this study suggest that ceramic brackets may lead to an increase in enamel fractures, particularly during bracket removal. The surface roughness of enamel exhibits variability depending on the adhesive substance and polishing methods used post-removal. Fixed orthodontic appliances could induce changes in enamel color, which may be alleviated by the use of nano-hydroxyapatite or specific polishing techniques. Further research is necessary to identify effective strategies for managing these color changes and improving the overall outcomes of fixed orthodontic treatment.

Do fluorescent agents alter the mechanical strength of orthodontic adhesives? An in vitro and clinical study

Background

Fluorescent agents are added to orthodontic adhesives with the aim of making them visible under ultraviolet (UV) light, which ensures the complete, safe removal of remnants after orthodontic treatment. However, it is necessary to evaluate if the mechanical strength of these materials is maintained. Therefore, this study evaluated whether the addition of fluorescent agents influences the shear bond strength and clinical performance of a UV light-sensitive adhesive system.

Methods

This study consisted of two stages: (1) In vitro phase: 40 human teeth were selected, divided at random into 2 groups (n = 20), according to the adhesive system used: UV group—adhesive with fluorescent agent, and control group—conventional adhesive. A shear bond strength test was performed using a DL 2000 universal testing machine, at a speed of 0.5 mm/min. The accessories were removed and an evaluation of the Adhesive Remnant Index (ARI) was carried out. (2) Clinical phase: 8 patients were selected and had their appliances bonded using the split-mouth design (160 teeth) with the same tested adhesive systems (UV, n = 80; control, n = 80). The patients were monitored for bonding failure for a period of 24 months. Statistical analysis was performed using the Independent t test, chi-squared tests, and Mann-Whitney test, at a level of significance of 5% and confidence interval of 95%.

Results

Regarding the in vitro phase, the shear bond strength test yielded similar results in the two groups (p > 0.05) and the ARI showed statistically significant differences between the groups with a score of 1 being the most frequent ARI for both groups (70%). In addition, there was no clinical difference in terms of bonding failure between the groups (p > 0.05).

Conclusion

The addition of fluorescent elements does not alter the mechanical strength and performance of the orthodontic adhesive and represents a viable alternative for clinical application.

Efficiency of different protocols for enamel clean-up after bracket debonding: an in vitro study

Objective:

This study aimed to assess the efficiency of six protocols for cleaning-up tooth enamel after bracket debonding.

Methods:

A total of 60 premolars were divided into six groups, according to the tools used for clean-up: 12-blade bur at low speed (G12L), 12-blade bur at high speed (G12H), 30-blade bur at low speed (G30L), DU10CO ORTHO polisher (GDU), Renew System (GR) and Diagloss polisher (GD). Mean roughness (Ra) and mean roughness depth (Rz) of enamel surface were analyzed with a profilometer. Paired t-test was used to assess Ra and Rz before and after enamel clean-up. ANOVA/Tukey tests were used for intergroup comparison. The duration of removal procedures was recorded. The association between time and variation in enamel roughness (∆Ra, ∆Rz) were evaluated by Pearson's correlation test. Enamel topography was assessed by scanning electron microscopy (SEM).

Results:

In Groups G12L and G12H, original enamel roughness did not change significantly. In Groups G30L, GDU, GR and GD, a smoother surface (p < 0.05) was found after clean-up. In Groups G30L and GD, the protocols used were more time-consuming than those used in the other groups. Negative and moderate correlation was observed between time and (∆Ra, ∆Rz); Ra and (∆Ra, ∆Rz); Rz (r = - 0.445, r = - 0.475, p < 0.01).

Conclusion:

All enamel clean-up protocols were efficient because they did not result in increased surface roughness. The longer the time spent performing the protocol, the lower the surface roughness.

Comparison of enamel discoloration associated with bonding with three different orthodontic adhesives and cleaning-up with four different procedures

OBJECTIVE

The aim of this study was to compare whether there was any difference in the enamel discoloration after staining when three orthodontic adhesives and four enamel clean-up methods were tested.

MATERIALS AND METHODS

Three types of orthodontic adhesives were used: chemically cured resin, light-cured resin and resin-modified glass-ionomer cement. A total of 120 human extracted premolars were included. 10 teeth of each orthodontic adhesive were randomly cleaned-up with one of four different procedures and stained in coffee for seven days: (1) carbide bur (TC); (2) carbide bur; Sof-Lex polishers (TC+SL); (3) carbide bur and one gloss polishers (TC+OG); and (4) carbide bur and PoGo polishers (TC+PG). Color measurements were made with Crystaleye dental spectrophotometer at baseline and after storage in a coffee solution one week. Two-way ANOVA and Bonferroni tests were used for statistical analyses (P<0.05).

RESULTS

The color change values of the adhesive materials in the TC groups were the greatest. The lowest ΔE* values were obtained from the TC+SL groups. However, there were no significant difference between the TC+SL and TC+PG groups (P>0.05). The resin-modified glass-ionomer cement groups showed the lowest color differences and chemically cured resin groups showed the highest ΔE* values among all the orthodontic adhesives (P<0.05).

CONCLUSION

The color change of enamel surface was affected by the type of adhesive materials and cleanup procedures.