Interplay between different manual toothbrushes and brushing loads on erosive tooth wear

Objective: To investigate the effect of different types of manual toothbrushes and brushing loads on the progression of erosive tooth wear (ETW) on enamel.Methods: Bovine enamel specimens (n = 10) were submitted to a 5-day erosive-abrasive cycling model (0.3 % citric acid for 5 min, artificial saliva for 60 min, 4x/day). Toothbrushing was carried out 2x/day for 15 s, according to the toothbrushes tested (ultra-soft (a): Curaprox 5460; ultra-soft (b): Sensodyne Repair & Protect; soft (a): Colgate Slim Soft; soft (b): Oral-B Indicator Plus; medium: Johnson's Professional; hard: Tek) and brushing loads (1.5 N, 3 N). Surface loss (SL, in um) was assessed by optical profilometry on conclusion of the cycling. Some of the toothbrush characteristics were evaluated. Data were statistically analyzed (alpha = 0.05).Results: For the 1.5 N load, the hard brush showed the highest SL value, with statistical significance. The other toothbrushes did not differ significantly, except that ultra-soft (a) caused significantly higher SL than ultra-soft (b). For the 3 N load, hard and soft (a) exhibited the highest SL. Soft (b) and medium had the lowest SL value, with statistical significance. Only soft (a) and ultra-soft (b) showed significant difference between loads, with lower SL for the load of 1.5 N. None of the toothbrush characteristics were significantly correlated with SL.Conclusions: Although different degrees of enamel surface loss were observed with use of the different toothbrushes, no association was found between the toothbrush characteristics and SL. Depending on the toothbrush, the force of brushing was capable of modulating the ETW of enamel. Based on the brushing loads usually applied by healthy individuals, hard brushes are not recommended for use by patients with ETW.Clinical significance: The use of hard bristle brushes is not recommended for use by individuals who exert healthy forces when brushing their teeth. The toothbrush characteristics are of secondary importance in terms of causing enamel loss in ETW.