Influence of nanoparticulated chitosan on the biomodification of eroded dentin: clinical and photographic longitudinal analysis of restorations

Longitudinal analyses of composite resin restoration on erosive lesions

Aim: To evaluate the influence of the biomodification of erosive lesions with a chitosan nanoformulation containing green tea (NanoCsQ) on the clinical performance of a composite resin. Methods: The study was performed in a split-mouth, randomized and double-blinded model with 20 patients with 40 erosive lesions. The patient’s teeth were randomized into two groups (n=20) according to the surface treatment: 1) Without biomodification (control), and 2) Biomodification with NanoCsQ solution (experimental). The lesions were restored with adhesive (Tetric N-bond, Ivoclar) and composite resin (IPS Empress Direct, Ivoclar). The restorations were polished and 7 days (baseline), 6 months, and 12 months later were evaluated according to the United States Public Health Service (USPHS) modified criteria, using clinical exam and photographics. Data were analyzed by Friedman’s and Wilcoxon signed-rank tests. Results: No significant differences were found between the control and experimental groups (p=0.423), and also among the follow-up periods (baseline, six months, and 12 months) (p=0.50). Regarding the retention criteria, 90% of the restoration had an alpha score in the control group. Only 10% of the restorations without biomodification (control) had a score charlie at the 12-month follow-up. None of the patients reported post-operatory sensitivity. Conclusion: The NanoCsQ solution did not negatively affect the performance of the composite resin restorations after 12 months.

Biomineralization induced by chitosan and collagen-based materials with fluoride for dentin coverage: Chemical and morphological analysis

The prevention and treatment of erosive tooth wear are becoming increasingly important due to its increasing prevalence. The use of natural solutions to modify dental surfaces has become an area of research. Organic materials such as chitosan and hydrolyzed collagen may be a promising option to treat dentin. This in vitro study aimed to evaluate the influence of chitosan or hydrolyzed collagen, alone or combined with acidulated phosphate fluoride (APF) gel, on the composition and morphology of dentin after erosion. Bovine dentin samples were prepared (n = 84) and treated with artificial saliva (AS, negative control); APF gel (F, positive control); chitosan solution (Chi); hydrolyzed collagen solution (Col); fluoride/chitosan composition (F_Chi); and fluoride/hydrolyzed collagen composition (F_Col). Erosive cycles (six cycles of immersion in orange juice for 1 min, followed by immersion in AS for 1 hr) were performed. The materials were characterized by their morphology, composition, and particle size distribution. Micro-energy dispersive X-ray fluorescence spectroscopy and scanning electron were used to evaluate the dentin's inorganic chemical composition and morphology. The F_Col and F groups had a reduction in calcium loss by 17 and 26%, respectively (p < .001). Both of these groups still had a covering layer of agglomerates at the dentin surface after the erosive cycles. The fluoridated chitosan or collagen solutions improved the dentin resistance to erosion as a novel hybrid-fluoride-based material approach to provide surface protection from erosion.