Effect of Water and Chlorhexidine with Different Pressures of Oral Irrigation Device on the Surface Roughness and Topography of Giomer

Abstract Objective: To evaluate the effect of different pressures of an oral irrigation device (OID) and the irrigation solution type on the surface roughness of the giomer restorative material. Material and Methods: In this in vitro study, disk-shaped giomer samples were fabricated and assigned to 5 groups (n=23): Group 1, storage in distilled water (control); Group 2, OID #7 pressure/ water; Group 3, OID #10 pressure/ water; Group 4, OID #7 pressure/ 0.05% CHX; Group 5, OID #10 pressure/ 0.05% CHX. The samples' treatment simulated a one-year application of OID. Surface roughness (Ra) and topography of the giomer were evaluated using profilometry and scanning electron microscopy. The data were analyzed with Paired t-test, Tukey, and ANOVA tests (α=0.05). Results: The Ra of the samples increased significantly after treatment with OID (p<0.001). The roughness increase in groups with a pressure of 10 was higher than those with a pressure of 7 (p<0.001). The effect of pressure on surface changes was significant (p<0.001). However, the solution type and the cumulative effect of these two factors were insignificant (p=0.08 and p=0.43, respectively). Conclusion: Oral irrigation device with both solutions significantly increased the surface roughness and topographic changes of the giomer. The severity of these changes was related to the device's pressure.

QMix® irrigant reduces lipopolysacharide (LPS) levels in an in vitro model

AbstractThe presence of endotoxin inside the root canal has been associated with periapical inflammation, bone resorption and symptomatic conditions.Objectives To determine, in vitro, the effect of QMix® and other three root canal irrigants in reducing the endotoxin content in root canals.Material and Methods Root canals of single-rooted teeth were prepared. Samples were detoxified with Co-60 irradiation and inoculated with E. coli LPS (24 h, at 37°C). After that period, samples were divided into 4 groups, according to the irrigation solution tested: QMix®, 17% EDTA, 2% chlorhexidine solution (CHX), and 3% sodium hypochlorite (NaOCl). LPS quantification was determined by Limulus Amebocyte Lysate (LAL) assay. The initial counting of endotoxins for all samples, and the determination of LPS levels in non-contaminated teeth and in contaminated teeth exposed only to non-pyrogenic water, were used as controls.Results QMix® reduced LPS levels, with a median value of 1.11 endotoxins units (EU)/mL (p<0.001). NaOCl (25.50 EU/mL), chlorhexidine (44.10 EU/mL) and positive control group (26.80 EU/mL) samples had similar results. Higher levels were found with EDTA (176.00 EU/mL) when compared to positive control (p<0.001). There was no significant difference among EDTA, NaOCl and CHX groups. Negative control group (0.005 EU/mL) had statistically significant lower levels of endotoxins when compared to all test groups (p<0.001).Conclusion QMix® decreased LPS levels when compared to the other groups (p<0.001). 3% NaOCl, 2% CHX and 17% EDTA were not able to significantly reduce the root canal endotoxins load.

Controle químico da placa. Estudo comparativo entre a clorhexidina e a alexidine. (Revisäo bibliográfica) / Chemical control of plaque. Comparative study between chlorhexidine and alexidine. (Bibliographic review)

O objetivo desse trabalho foi analisar, via literatura, as dificuldades existentes em relaçäo controle mecanico da placa bacteriana dental; estudar as possibilidades da utilizaçäo do controle químico da placa. Considerando que entre os agentes "anti-placa" mais promissores, se encontram as bisbiguanidas - clorhexidina e alexidina - nesse trabalho foram estudados tanto os aspectos positivos como os negativos de ambas. Säo discutidos os pontos comuns e aqueles que as distinguem