Tooth enamel properties and morphology after microabrasion: an in situ study

Effects of microabrasion association to at-home bleaching on hydrogen peroxide penetration and color change

PURPOSE

This study aimed to quantify the penetration of hydrogen peroxide (HP) inside the pulp cavity and color change with two different concentrations of HP to at-home bleaching associated or not with enamel microabrasion (MA).

METHODS

Forty healthy premolars were randomly divided in four groups (n = 10): only HP4%, MA + HP4%, only HP10%, MA + HP10%. The concentration (μg/ml) of HP was assessed using UV-Vis spectrophotometry. The color change (ΔEab , ΔE00 and WID ) was evaluated before and one-week after bleaching. Data were evaluated for a two-way ANOVA and the Tukey's test (α = 0.05).

RESULTS

The application of MA increased the amounts of HP inside the pulp chamber when compared to without MA, as well as PH10% when compared to PH4% (p < 0.0001). PH10% showed higher WID when compared to PH4%. No significant difference was observed when ΔEab , and ΔE00 were used.

CONCLUSIONS

The enamel MA before at-home bleaching promotes greater penetration of HP, although this procedure did not significantly affect the color change.

CLINICAL SIGNIFICANCE

Since greater penetration of HP into the pulp chamber was detected when home bleaching was applied immediately after MA, the clinician should not apply home bleaching gels in the same session when MA was performed.

Resolution of a fluorosis case through the association of minimally invasive techniques

Color changes may interfere with smile balance and they represent a clinical challenge to dentists. Dental fluorosis originates from intrinsic factors and it is a disorder of enamel formation during the phase of teeth development, resulting in the change of enamel color. This clinical case report aimed to present the resolution of a case of dental fluorosis through the association of minimally invasive techniques, namely microabrasion and tooth bleaching. A 27-year-old male patient sought the dental clinic of the School of Dentistry of Piracicaba (FOP - UNICAMP, Brazil) presenting striped and symmetrical white stains and generalized chromogenic biofilm. After anamnesis and clinical examination, the patient was diagnosed with fluorosis stains. Initially, adequacy of the oral environment was performed with prophylaxis and supragingival scraping. Then, the enamel microabrasion technique was performed with 6% hydrochloric acid associated with silicon carbide (Whiteness RM - FGM) and supervised at-home bleaching was performed with 16% carbamide peroxide (Whiteness Simple 16% - FGM). In conclusion, the treatment performed reestablished the aesthetics and harmony of smile color with minimally invasive procedures without causing tooth sensitivity.

Power bleaching enhances resin infiltration masking effect of dental fluorosis. A randomized clinical trial

OBJECTIVES

Patients with moderate dental fluorosis often feel esthetically compromised. Aim of this RCT was to evaluate the objectively and self-assessed masking effect of resin infiltration alone or in combination with in-office bleaching on dental fluorosis in adults.

METHODS

Twenty-seven patients (9 male, 18 female, 24.81 ± 3.7 yrs) with 410 fluorotic teeth (TF 1-4) were randomly assigned to a treatment (BLI) or control group (NBLI). Patients underwent in-office bleaching (25% H₂O₂) in the BLI or a placebo bleaching (ACP gel) in the NBLI group followed by resin infiltration after two weeks. Standardized digital photographs were obtained at baseline; after bleaching; before and after resin infiltration and after 1, 3, and 6 months. Color differences (ΔE) between sound and fluorotic areas were calculated and patient satisfaction was evaluated using a VAS (1-10).

RESULTS

Statistical analysis revealed significant differences in the mean ΔE values 6 months after resin infiltration between the BLI (ΔE = 1.41) and the NBLI group (ΔE = 4.33) (p = 0.024). VAS values increased after resin infiltration (p < 0.05) in both groups. After 3 months patients in the BLI group had higher VAS values than in the NBLI group (p = 0.029).

CONCLUSIONS

Findings of this study suggest that resin infiltration alone can effectively mask mild to moderate dental fluorosis in young adults. In-office bleaching with 25% H₂O₂ before resin infiltration provides significantly better masking effects.

CLINICAL SIGNIFICANCE

Resin infiltration is a safe and efficient treatment option for masking fluorotic opacities. A priori in-office bleaching with 25% H₂O₂ enhances the masking effect. This controlled clinical trial is registered in the German Clinical Trials Register #DRKS00010465.