Cellular differentiation, bioactive and mechanical properties of experimental light-curing pulp protection materials.

OBJECTIVE: Materials for pulp protection should have therapeutic properties in order to stimulate remineralization and pulp reparative processes. The aim of this study was to evaluate the mechanical properties, biocompatibility, cell differentiation and bioactivity of experimental light-curable resin-based materials containing bioactive micro-fillers. METHODS: Four calcium-phosphosilicate micro-fillers were prepared and incorporated into a resin blend: 1) Bioglass 45S5 (BAG); 2) zinc-doped bioglass (BAG-Zn); 3) ßTCP-modified calcium silicate (ß-CS); 4) zinc-doped ß-CS (ß-CS-Zn). These experimental resins were tested for flexural strength (FS) and fracture toughness (FT) after 24h and 30-day storage in simulated body fluid (SBF). Cytotoxicity was evaluated using MTT assay, while bioactivity was evaluated using mineralization and gene expression assays (Runx-2 & ALP). RESULTS: The lowest FS and FT at 24h was attained with ß-CS resin, while all the other tested materials exhibited a decrease in FS after prolonged storage in SBF. ß-CS-Zn maintained a stable FT after 30-day SBF aging. Incorporation of bioactive micro-fillers had no negative effect on the biocompatibility of the experimental materials tested in this study. The inclusion of zinc-doped fillers significantly increased the cellular remineralization potential and expression of the osteogenic genes Runx2 and ALP (p<0.05). SIGNIFICANCE: The innovative materials tested in this study, in particular those containing ß-CS-Zn and BAG-Zn may promote cell differentiation and mineralization. Thus, these materials might represent suitable therapeutic pulp protection materials for minimally invasive and atraumatic restorative treatments.

Effects of bleaching agents containing fluoride and calcium on human enamel.

OBJECTIVE: Since little is known about the effects of carbamide peroxide (CP) containing fluoride (F) or calcium (Ca), this study evaluated the effects of experimental and commercially available bleaching agents, with or without F and Ca, on enamel. METHOD AND MATERIALS: Sound enamel slabs were randomly divided into six groups (n = 10): placebo gel (PLA); Whiteness (WHI-10% CP; FGM); Opalescence F (OPA-10% CP+F; Ultradent); Pola Night F (PN-10% CP+F; SDI); and experimental gels: 10% CP + F (CPF) and 10% CP + Ca (CPCa). The samples were submitted to 6-hour gel applications daily for 14 days and stored in remineralizing solution after treatment. Enamel microhardness measurements were performed at baseline and after bleaching. In addition, the analytical concentrations of F and Ca and the pH of the water used to rinse the bleached surface were analyzed by means of ion-selective electrode, atomic absorption spectroscopy, and pH meter, respectively. RESULTS: Enamel surface microhardness significantly decreased after bleaching with nonenhanced 10% CP (WHI). The chemical analyses suggest F uptake promoted by high-concentrate F bleaching gels (CPF, OPA, and PN) and a F loss with nonenhanced 10% CP bleaching gels (PLA, WHI). CP agent enhanced with Ca (CPCa) also caused Ca enamel uptake. CONCLUSION: Enamel was susceptible to mineral changes during bleaching treatment, but mineral loss was minimized by the addition of F and Ca to bleaching agents.

Reanatomização de incisivos laterais conóides:relato de caso / Reshaping of peg-shaped lateralincisors: case report

A solução de problemas estéticos na Odontologia restauradoratem se tornado um desafio cada vez maior devido ao elevado nível de exigênciados pacientes, que buscam soluções para resgatar a condição de naturalidadedos dentes e sua compatibilidade com o tecido gengival, requisitos básicos daOdontologia estética. Situações que antes passavam despercebidas, hoje são prérequisitospara a aceitação do trabalho restaurador. Neste caso é apresentado orelato da correção estética de incisivos laterais conóides, por meio do empregoda técnica direta, com a utilização de resina composta, para a obtenção de umsorriso harmônico.

To solve esthetic problems in the restorativeDentistry has become a bigger challengeas the requirement level of the patients, theysearch solutions to rescue the natural appearanceof teeth and your compatibility with the gengivaltissue, basic elements for Esthetic Dentistry.Situations left as less important in the past, innowadays must be considered in order to theacceptance of the restorative work. The articledescribes a clinical case of esthetic correction ofpeg-shaped lateral incisors that used to contributeto a disharmonious smile.