Abstract Objective This study aimed to evaluate the effects of different toothpastes on the surface wear of enamel, dentin, composite resin (CR), and resin-modified glass ionomer cement (RMGIC), and to perform a topographic analysis of the surfaces, based on representative images generated by atomic force microscopy (AFM) after erosion-abrasion cycles. Methodology One hundred and forty bovine incisors were collected and divided into two groups: 72 enamel and 72 dentin blocks (4×4 mm). Half of the specimens were restored with CR (Filtek Z350 XT) and the other half with RMGIC (Fuji II LC). Then, samples were submitted to a demineralization cycle (5 days, 4×2 min/day, 1% citric acid, pH 3.2) and exposed to three different toothpastes (2×15 s/day): without fluoride (WF, n=12), sodium fluoride-based (NaF, n=12), and stannous fluoride-based (SnF2, n=12). Surface wear, as well as restoration interfaces wear, were investigated by profilometry of the dental substrates and restorative materials. All representative surfaces underwent AFM analysis. Data were analyzed by two-way analysis of variance and Tukey’s tests (α=0.05). Results NaF-based toothpaste caused the greater dentin surface wear (p<0.05). Toothpastes affected only enamel-restoration interfaces. AFM analysis showed precipitate formation in dentinal tubules caused by the use of fluoride toothpastes. Conclusions NaF-based toothpastes had no protective effect on enamel adjacent to CR and RMGIC against erosion-abrasion challenges, nor on dentin adjacent to RMGIC material. SnF2-based toothpastes caused more damage to interfaces between enamel and RMGIC.

AIM: This study evaluated saliva effects on enamel morphology surface after microabrasion technique. METHODS: Enamel blocks (16 mm2) obtained from bovine incisors were divided into 9 groups as follows: one control group (no treatment), four groups with microabrasion treatment using 35% phosphoric acid and pumice (H3PO4+Pum) and other four groups treated with 6.6% hydrochloric acid and silica (HCl+Sil). One group of each treatment was submitted to 4 frames of saliva exposure: without exposure, 1-h exposure, 24-h exposure, and 7-days exposure on in situ regimen. Nineteen volunteers (n=19), considered as statistical blocks, used an intraoral appliance containing the specimens, for 7 days. Enamel roughness (Ra) was tested before and after treatment, and after saliva exposure. Confocal laser scanning microscopy (CLSM) was used to evaluate qualitatively the enamel morphology. RESULTS: All groups exhibited increased Ra after microabrasion. With regards to saliva exposure, the treatment with HCl+Sil presented more susceptibility to the saliva action, but no period of time was efficient in re-establishing this characteristic compared with the control group. CLSM analysis showed reduction of the micro-abrasive damages during the experimental times. CONCLUSIONS: Seven days of saliva exposure were not sufficient for the treated enamel to reach its normal characteristics compared with the control group.

OBJETIVO: o propósito desse estudo foi analisar, por meio de modelos de estudo e paquímetro digital, a proporção largura/altura e o zênite gengival (ZG) em pacientes com agenesia bilateral do incisivo lateral superior após o tratamento. MÉTODOS: a amostra consistiu de 52 voluntários divididos em 3 grupos: GBR (n=18), pacientes com agenesia bilateral tratados com reanatomizações dentárias; GBI (n=10), pacientes com agenesia bilateral tratados com implantes; e GC (n=24), grupo controle. Os dados foram avaliados por meio dos testes de Shapiro-Wilk, Wilcoxon, Kruskal-Wallis, teste t, ANOVA (p<0,05) e correlação de Spearman. RESULTADOS: para a proporção largura/altura dos incisivos laterais, o GBI apresentou menores valores (0,72 direito e esquerdo), quando comparado aos demais. Porém, a comparação intergrupos revelou diferenças estatisticamente significativas para o incisivo lateral direito (GBI x GC) e para o canino (GBR x GC). A avaliação das medianas obtidas para o ZG demonstrou que o GBR foi o mais destoante (0,5 direito e 0,48 esquerdo), e que o GBI (0,95 direito e 0,98 esquerdo) e o GC (0,98 direito e 0,8 esquerdo) apresentaram valores semelhantes, sem diferença estatisticamente significativa (p>0,05). Os valores obtidos para os lados direito e esquerdo foram considerados iguais dentro de cada grupo. CONCLUSÃO: embora não tenham sido encontradas diferenças estatísticas na comparação entre os grupos, pela análise descritiva dos dados, o GBI foi o grupo que apresentou as medidas mais destoantes dos demais em relação à proporção largura/altura, sendo que, para o zênite gengival, a maior diferença observada foi no GBR.

OBJECTIVE: The purpose of this study was to evaluate the width/length ratio and the gingival zenith (GZ), by means of dental casts and digital caliper, in patients with missing maxillary lateral incisors after treatment. METHODS: The sample was composed of 52 subjects divided into 3 groups: BRG (n = 18), patients with bilateral agenesis treated with tooth re-contouring; BIG (n = 10) patients with agenesis treated with implants and CG (n = 24), control group. The data were analyzed using Shapiro-Wilk, Spearman correlation, Wilcoxon, Kruskal-Wallis, t test and ANOVA tests (p < 0.05). RESULTS: For the width/length ratio of the lateral incisors, BIG presented the lowest mean values (0.72 right and left), when compared with other groups. However, comparison between groups presented statistically significant differences for the right lateral incisor (BIG x CG) and for the canine (BRG x CG). GZ data evaluation showed the greatest difference for BRG (0.5 right and 0.48 left). BIG (0.95 right and 0.98 left) and CG (0.98 right and 0.8 left) presented more similar values, nevertheless, without statistical difference (p > 0.05). GZ data for the right and left sides of the smile were not considered statistically different. CONCLUSION: Although no statistical difference was found in the comparison between the groups, analysis of the descriptive values showed that group BIG showed the greatest difference in values with regard to width/length ratio. Regarding gingival zenith, BRG showed the greatest difference.