do Carmo SS, N espoli FFP, Bachmann L, Miranda CES, Castro-Raucci LMS, Oliveira IR, Raucci-Neto W. Influence of early mineral deposits of silicate-and aluminate-based cements on push-out bond strength to root dentine. International Endodontic Journal, 51, 92-101, 2018. Aim To evaluate mineral trioxide aggregate (MTA), Biodentine and several formulations of calcium aluminate cements (CACb) in terms of their ability to release calcium ions (Ca 2+ ) and form apatite-like precipitates after short-term immersion in phosphate-buffered saline (PBS) and its influence on the bond strength to the root-end cavity. Methodology Ten samples of MTA, Biodentine, CACb and calcium-enriched aluminate cement (CACb+) were placed in contact with PBS or deionized water for 14 days. The cement surfaces were analysed using SEM, EDS-X and FTIR. Eighty standardized root-end cavities filled with the cements (ten samples of each cement) were immersed in PBS or deionized water for 14 days, and the bond strengths were measured. Data from the push-out test were analysed using two-way ANOVA and Tukey's tests (a = 0.05).Results A gradual decrease was observed in Ca 2+ concentrations and pH of all solutions. FTIR bands of different phases of hydroxyapatite were identified. Crystalline formation was observed on the surface of all cements after immersion in PBS. No significant difference was observed in the bond strength of the test materials (P > 0.05); however, all cements without contact with the solution revealed significantly lower bond strength values than those in contact with the solution (P < 0.05). Conclusion MTA, Biodentine, CACb e CACb+ were associated with precipitation of crystals after being in contact with PBS for 14 days, indicated by different phases of hydroxyapatite crystalline formation, which also increased dislodgment resistance of the material from root-end cavities. The CACb+ had similar bond strengths and precipitation of crystals to existing materials.

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CAC+ supported the acquisition of the osteogenic cell phenotype in vitro, rendering this novel material a potential alternative to MTA in endodontic procedures. Further in vivo studies are needed to verify if the beneficial in vitro effects of CAC+ on osteoblastic cells correspond to an increase and/or acceleration of bone repair in the periapical region.

Dental caries is still the most prevalent chronic disease affecting human populations. Among the preventive treatments performed, it has been reported that laser irradiation combined with topical fluoride can induce an even greater increase in enamel caries resistance. The aim of this study was to evaluate the Nd:YAG laser, with or without fluoride, in occlusal caries prevention of the primary dentition. A double-blind split-mouth study design was used. Fifty-two children with high caries risk (7.6 ± 1.4 years) were selected and received the following: G1--the first molar was a negative control, and the second received a resin sealant; G2--the first molar was a negative control, and the second received laser irradiation (50 mJ, 10 Hz, 0.5 W); G3--the first molar received only acidulate phosphate fluoride (APF), and the second received APF + laser; G4--fisrt molar received only fluoride varnish, and the second received fluoride varnish + laser. Patients were followed up to 12 months to evaluate the presence of white-spot lesions and/or caries cavities by three calibrated observers. Thirty-five patients completed the study. Significant differences were found between the treatment and control groups (p < 0.05). The laser-alone and resin sealant resulted in statistically lower caries formation than the negative control group (p < 0.05). Nd:YAG laser irradiation in primary teeth effectively prevented occlusal caries in pits and fissures when used alone with lower energy over a 1-year period.