This study analyzed the effect of prior application of copaiba oil (CO) emulsions as a dentin cleaning substance on microleakage and microtensile adhesive strength. Twenty-five premolars and sixty-four molars were used for microleakage and microtensile assays. For the microleakage assays, specimens with standard class V cavities were divided (n = 5), according to the tested CO emulsions: CO10%X, CO10%Y, and CO10%Z, as well as chlorhexidine 2% (CHX) and distilled water (DW), as positive and negative controls, respectively. Restorations were performed using the Adper Single Bond® and/or Clearfil SE Bond® systems. Cervical, occlusal, distal and mesial sections were assessed for tracer penetration degree at the composite/tooth interface. For the microtensile assay, healthy molars were divided into sixteen groups, in which artificial caries were induced in half of the groups. Dentin surfaces were treated with CO10%X and CO10%Y, CHX and DW. Microtensile bond strength was measured by fixing each sample to the plate of a universal testing machine operated at a speed of 0.5 mm/minute until failure. Dentin treated with CO10%X showed a lower infiltration rate than dentin treated with the other CO emulsions, CHX2% and DW. According to the microtensile assay, both healthy and affected dentin treated with CO10%X and Adper Single Bond® adhesive system presented higher adhesive strength. CO emulsion, used as a dentin biomodifier, interfered positively in microleakage and improved adhesive strength after acid etching in the Adper Single Bond® adhesive system, or before applying the Clearfil SE Bond® self-etching system.

Aim. This study sets out to evaluate the antiproteolytic activity of copaiba oil-based emulsion at the resin/dentin adhesive interface union formed with conventional and self-etching adhesives systems. Methods. At in situ zymography, 30 teeth were sectioned 2 mm below the enamel-dentin junction; a smear layer was standardized and subdivided into four groups. Gelatin conjugated with fluorescein was used and taken to the fluorescence microscope for evaluation. In cytotoxicity, the Trypan Blue method was used at four different time points. The tested groups were (G1) control with distilled water; (G2) 2% chlorhexidine (CLX); (G3) emulsion based on copaiba oil (EC) 10% + X; (G4) 10% EC + Y; and (G5) EC 10% alkaline. The zymographic assay used the same groups described, but in 30 seconds and 10 and 20 minutes. HT1080 cells were incubated and submitted to electrophoresis. The gel was analyzed using ImageJ software. Mann–Whitney and Kruskal–Wallis tests were used in the statistical analysis ( p < 0.05 ). Results. ECs showed higher cell viability in the cytotoxicity test and showed a significant difference in 10 and 20 minutes. In the zymographic assay, alkaline EC reduced 67% of MMP-2 activity and 44% of MMP-9 compared to 2% chlorhexidine. At in situ zymography in qualitative evaluation, all groups tested showed inhibition of activity in metalloproteinases. Conclusion. EC showed activity in the inhibition of metalloproteinases in vitro and in situ, especially the alkaline one. The survey shows the possibility of using ECs, a product from Amazonian biodiversity, as a biomodifier in dentistry.

This study aimed to evaluate in vitro the pharmacological stability of the dentin biomodifiers emulsions based on copaiba oil X, at 0, 3, 6, 9, 12, 18, and 24 months, and copaiba oil Y, at 0, 6, and 12 months. The emulsions were stored in different environments and analyzed through centrifugation, pH, and density tests, as well as their organoleptic and microbiological characters were investigated. Emulsion X did not show phase separation at 0 and 6 months in the freezer and fridge and showed cleavage in all environments after 12 months. The Y emulsion did not exhibit phase separation at 0 and 6 months in the stove, fridge, room temperature protected, and exposed to light. Still, after 18 and 24 months, phase separation occurred in all analyzed environments. The emulsions X and Y did not show contamination at 12 months. In the organoleptic test, the main change observed was color. The emulsion X presented the slightest deviation of pH in the room temperature protected from light, air conditioning, and fridge while the Y emulsion at 6 months presented a smaller variation in the freezer and fridge, and at 12 months, freezer, stove, and air conditioning. Regarding density, emulsion X at 24 months showed a very slight deviation, and emulsion Y remained stable in all environments at 12 months. The emulsions tested showed stability for 12 months, with the best storage environment being the fridge. The analysis at 18 and 24 months reinforced the fridge as an ideal environment for storage.