Microinvasive esthetic approach for deep enamel white spot lesion.

The white spot lesion on the dental enamel is an optical alteration that compromises the esthetics of smile. It can be caused by many factors, among them, defects in mineralization and formation of tooth enamel. Resin infiltrants are agents that penetrate, by capillarity, through the pores of the demineralized or hypomineralized enamel, altering the refractive index (RI) of the tooth structure and totally or partially masking the appearance of the white spot. The aim of this work was to report the use of resin infiltration to minimize the visualization of white spot lesion, present in an upper central incisor, as a microinvasive approach for the esthetic treatment of deep enamel hypomineralization. A 20-year-old female patient sought care with the esthetic complaint of extensive white spot lesion on the buccal face of her upper right central incisor. The diagnosis established was a deep white stain associated with the incisor molar hypomineralization syndrome, and the treatment of choice for the resolution of the case was the application of the Icon® resin infiltrant (DMG, Hamburg, Germany). To reach the body of the lesion, three cycles of acid erosion, using 15% HCl, were necessary to obtain a satisfactory aspect of masking the white lesion. A camouflage effect of the deep white spot lesion was achieved with the use of the resin infiltration, without the need of additional and irreversible wear of the dental structure.

Comparação do efeito de diferentes protocolos de polimento na rugosidade superficial de restaurações de resina composta / Comparison of the effect of different polishing protocols on surface rugosity of composite resin restorations

Objetivo: o objetivo do presente estudo foi comparar a influência de diferentes protocolos de polimento sobre a rugosidade superficial de uma resina composta nanoparticulada. Metodologia: foram confeccionados 30 corpos de prova (1,5 mm espessura e 6 mm diâmetro), divididos em 3 grupos (n=10), de acordo com o tipo de polimento realizado: 1. Grupo controle; 2. Borrachas abrasivas em 3 granulações (grossa, média, fina); 3 Borracha abrasiva de granulação única. Todos os grupos receberam acabamento com lixa d'água, simulando uma ponta diamantada fina, sendo que o grupo controle não recebeu o polimento com borracha, após esse acabamento. Após o polimento dos grupos 2 e 3, a rugosidade superficial de cada corpo de prova, dos três grupos, foi avaliada em 3 medidas, através de rugosímetro, sendo calculada a média aritmética dos 3 valores picos e vales. A análise estatística inferencial foi feita por meio da ANOVA a 1-critério e teste de Tukey, para comparações múltiplas, com nível de significância de 5%. Resultados: observaram-se maiores valores de rugosidade no grupo controle (3,31µm), seguido do polimento de 1 passo (1,53µm) e 3 passos (0,48µm). Conclusão: diante disso, observa-se alta rugosidade superficial no acabamento com pontas diamantadas, simulado pelo grupo controle, e sua redução após o polimento. Entretanto, apenas o sistema de 3 passos foi capaz de produzir uma lisura superficial clinicamente aceitável.

Aim: the aim of the present study was to compare the influence of different polishing protocols on the surface roughness of a nanoparticulate composite resin. Methodology: Thirty specimens (1.5 mm thickness and 6 mm diameter) were made and divided into 3 groups (n = 10), according to the type of polishing performed: 1. Control group; 2. 3 grit abrasive rubs (thick, medium, thin); 3 Single grain abrasive rubber. All groups were finished with sandpaper, simulating a fine diamond tip, and the control group did not receive rubber polishing after this finish. After groups 2 and 3 polishing, the surface roughness of each specimen of the three groups were evaluated in 3 measurements by means of roughness, and the arithmetic mean of the 3 peaks and valleys (Ra) values were calculated. Inferential statistical analysis was performed using one-way ANOVA and Tukey test for multiple comparisons, with a significance level of 5%. Results: higher roughness values were observed in the control group (3.31µm), followed by 1-step (1.53µm) and 3-step (0.48µm) polishing. Conclusion: therefore, it is noticed a high surface roughness in the diamond-tipped finish, simulated by the control group, which was reduced after polishing. However, only the 3-step system was able to produce a clinically acceptable surface smoothness.

Effect of surface protection on the permeability of eroded dentin.

CONTEXT: Eroded dentin might present the opening of dentinal tubules, increasing permeability, and consequently dentinal hypersensitivity. AIMS: This study evaluated the permeability of dentin surfaces exposed to different levels of erosion and methods of surface protection. MATERIALS AND METHODS: Dentine samples (3 mm × 3 mm × 1 mm) were prepared from bovine incisors (n = 90) and divided into three groups according to the method of controlling erosive challenge: Negative control, topical fluoride application, and glass ionomer sealant. Subsequently, they were randomly divided into three subgroups according to the exposure of simulated gastric acid solution (Demineralization - DES) (5% HCl, pH = 2.2), and remineralization (RE); negative control, 9 and 18 cycles DES-RE. The dentin permeability was measured by assessing the hydraulic conductance (µl/min.cmH2O.cm2). Statistical analysis was performed by two-way ANOVA and Tukey's test. RESULTS AND CONCLUSIONS: Greater permeability was observed after 18 erosive cycles, followed by exposure to 9 cycles and negative control (P < 0.0001). The application of glass ionomer sealant resulted in a major reduction of the hydraulic conductivity, regardless of the erosive challenge. Control groups and topical fluoride application showed similar results. In conclusion, the severity of erosive challenge contributed to the increase of dentin permeability. Besides, the glass ionomer sealant was the only protection agent that promoted significant effects in dentin permeability.