Dentifrices, Surface Roughness and Depth Loss of Restorative Materials

Objectives: Toothbrush abrasion may cause significant roughness, and depth loss, in tooth structure and restorations, over time. Dentifrice use can either enhance or limit the degree of surface roughness on tooth structure and restorative materials. This study’s purpose was to compare surface roughness (Ra), and depth loss (DL) caused from brushing with dentifrice on dentin and composites.
Methods: Sixteen samples per composite resin consisting of ACTIVA™ BioACTIVE-RESTORATIVE™ (AB) and Esthet-X HD (EX), along with sixteen dentin samples, were embedded in acrylic resin and polished. Samples were randomly grouped (n=8/2gp), according to dentifrice, Myntsmile (MS) or Crest Pro-Health (CPH). Samples were brushed in a thoroughly mixed solution containing 60ml DI water and 37.5mg dentifrice at 1.5Hz and 350g force for 10,000x with rotation every 2,500x to ensure uniform brushing. Pre- and post-brushing measurements were made with contact profilometer for Ra and DL data. Ra and DL data were compared independently using a two-way ANOVA SNK with P<0.05 for significance.
Results: MS and CPH caused significantly less Ra on AB and EX compared to dentin (P<0.001). Ra caused by MyntSmile was not different between AB and EX. However, for CPH the Ra for EX was significantly greater than AB (P<0.001).
MS and CPH caused significantly less DL on AB and EX compared to dentin (P<0.001). There was no statistical difference between AB and EX (P=0.959) for MS. CPH caused more DL on EX than AB (P=0.006).
Conclusions: MyntSmile caused statistically less surface roughness and less loss than Crest Pro-Health in all samples. Activa and Esthet-X resisted both surface roughness and loss better than dentin. Activa was statistically better than Esthet-X at resisting both surface roughness and loss from Crest Pro-Health, being the more abrasive dentifrice. Clinically, these results may be less severe as the experimental brushing technique simulated an aggressive challenge.