Effect of calcium fluoride nanoparticles in prevention of demineralization during orthodontic fixed appliance treatment: a randomized clinical trial.

BACKGROUND: White spot lesions (WSLs) are the most common complications of fixed appliance orthodontic treatment. OBJECTIVES: To evaluate the effectiveness of calcium fluoride nanoparticles-containing orthodontic primer (nCaF2-primer) in preventing the incidence of WSLs during orthodontic treatment. TRIAL DESIGN: Single-centre, double-blinded, split-mouth, randomized clinical trial. METHODS: The sample involved 31 orthodontic patients (≥12 years). Participants were recruited using a simple nonstratified randomization. Data collection, measurements, and analysis were performed blindly. Outcome measures included comparing the effect of nCaF2-primer with control primer (Transbond) regarding the degree of demineralization (DIAGNOdent pen), Streptococcus mutans (S. mutans) bacterial counting [real-time polymerase chain reaction device (PCR)], and WSLs incidence (pre- and post-operative photographs). The measurements were performed before bonding, 1, 3, and 6 months after bonding and after appliance removal. A two-way repeated measure analysis of variance test (for DIAGNOdent pen scores), and Wilcoxon signed-rank test (for the difference between bacterial counting and WSLs incidence) were used (P < 0.05). RESULTS: Thirty-one patients were recruited and randomized (mean age 17.9 ± 2.45 years). For the primary outcome (DIAGNOdent pen scores) and secondary outcome of S. mutans counting: 31 patients (310 teeth for each group) were included in scoring at T1 and T3, and 30 patients (300 teeth) were included at T6. While for the photographic scores, 26 patients were included after bracket bonding. The demineralization scores showed significant differences at all-time intervals within the 6 months after bracket bonding which was more noticeable after the first month. There was a significant difference in bacterial count between the two primer groups at the T1 only. Regarding photographic scores, there were no significant differences in the WSLs incidence between the two primers groups after brackets removal. No harm was detected during treatment, except the usual pain/gingival irritation. CONCLUSIONS: nCaF2-primer effectively decreased demineralization scores within the 6 months after bracket bonding. Moreover, it significantly reduced S. mutans colonization after the first month. However, the tested primer did not have an extra advantage in preventing WSLs development at the clinical level after appliance removal. TRIAL REGISTRATION: The trial was registered with ClinicalTrials.gov on 8 May 2021 (registration number: NCT04994314).

Evaluation of a newly developed calcium fluoride nanoparticles-containing orthodontic primer: An in-vitro study.

OBJECTIVES: Fluoride and calcium ions have the ability to reduce the formation of white spot lesions (WSL) in enamel. This study aimed to develop a novel orthodontic primer that incorporates calcium fluoride nanoparticles (nCaF2) and investigate its cytotoxic and physical properties as this primer could enhance the remineralization process when used with the conventional acid etching technique. MATERIALS AND METHODS: Three groups of the newly introduced primers were prepared by adding and mixing nCaF2 (Nanoshell Company, USA at 5%, 10%, 20% in weight) to Transbond™ XT orthodontic primers (3M-Unitek, Monrovia, USA). X-Ray Diffraction (XRD) was performed to verify and evaluate the phase of the nanopowders. Field Emission Scanning Electron Microscope (FESEM) observation was used to assess the homogeneity of tested primers, and Energy Dispersive X-Ray Spectroscopy (EDS) was performed to analyze elements of the prepared samples. The three primer groups were compared to the control primer (without the addition of nCaF2) in terms of cytotoxic behavior, homogeneity, agglomeration, shear bond strength (SBS), and adhesive remnant index (ARI). RESULTS: nCaF2 primers with all the prepared concentrations revealed good homogeneity with no apparent agglomeration after four months of mixing. Cytotoxicity of the new primers was higher than that of the control primer, but it was within the accepted limits of the ISO standards (70% cell viability). While the SBS and ARI values were comparable with the control primer (p > 0.05). CONCLUSIONS: The newly developed orthodontic primers with different concentrations of nCaF2 (5%, 10%, and 20%) showed a homogenous distribution of nCaF2 within the primers with no apparent agglomeration, acceptable cytotoxic level, adequate SBS, and ARI. Future clinical testing of nCaF2-containing orthodontic primer as a preventive measure for WSLs during fixed orthodontic treatment is suggested.