Effect of sodium hypochlorite and edta irrigation, individually and in alternation, on dentin microhardness at the furcation area of mandibular molars

The aim of this study was to evaluate the effect of irrigation regimens on dentin microhardness at the furcation area of mandibular molars, using sodium hypochlorite and ethylenediaminetetraacetic acid (EDTA), individually and in alternation. The occlusal surface and the roots of 20 non-carious extracted human permanent mandibular molars were cut transversally and discarded. The tooth blocks were embedded in acrylic resin and randomly assigned to 4 groups (n=5) according to the irrigating regimens: 1% NaOCl solution, 17% EDTA solution, 1% NaOCl and 17% EDTA and distilled water (control). Knoop microhardness of dentin at the furcation area was evaluated. Data were analyzed using one-way ANOVA and Tukey's multiple comparison tests (&#945;=0.05). The results of this study indicated that all irrigation solutions, except for distilled water (control), decreased dentin microhardness. EDTA did not show a significant difference with NaOCl/EDTA (p&gt;0.05), but showed a significant difference with NaOCl (p<0.01). EDTA and NaOCl/EDTA showed a maximum decrease in microhardness. The 17% EDTA solution, either alone or in combination with 1% NaOCl reduced significantly dentin microhardness at the furcation area of mandibular molars

Chitosan: effect of a new chelating agent on the microhardness of root dentin

The effect of solutions of 0.2% chitosan, 15% EDTA and 10% citric acid on the microhardness of root dentin was evaluated comparatively in this study. Thirteen sound human maxillary central incisors were selected and decoronated at the cementoenamel junction. Ten roots were set into rapid polymerization acrylic resin and the root/resin block was fitted to the cutting machine to obtain slices from the cervical third. The first slice was discarded and the second slice was divided into four quadrants. Each quadrant was used to construct a sample, so that 4 specimens were obtained from each root slice, being one for each chelating solution to be tested: 15% EDTA, 10% citric acid, 0.2% chitosan and distilled water (control). The specimens were exposed to 50 &#956;L of the solution for 5 min, and then washed in distilled water. A microhardness tester (Knoop hardness) with a 10 g load was used for 15 s. Data were analyzed statistically by one-way ANOVA and Tukey-Kramer test (&#945;=0.05). The other 3 roots had the canals instrumented and irrigated at the end of the biomechanical preparation with the test solutions, and then examined by scanning electron microscopy (SEM) for qualitative analysis. All solutions reduced the microhardness of root dentin in a way that was statistically similar to each other (p>0.05) but significantly different from the control (p>0.05). The SEM micrographs showed that the three solutions removed smear layer from the middle third of the root canal. In conclusion, 0.2% chitosan, 15% EDTA and 10% citric acid showed similar effects in reducing dentin microhardness

Comparative effects of final canal irrigation with chitosan and EDTA

Chitosan is a natural, biocompatible chelating substance with potential for dental use. This study compared the effects of final canal irrigation with chitosan and EDTA on dentin microhardness, sealer dentin tubules penetration capacity, and push-out strength. Methodology: Fifty canine roots were distributed according to the final irrigation protocol (n=10): G1- 15% EDTA with conventional irrigation; G2- 15% EDTA with Endovac; G3- 0.2% chitosan with conventional irrigation; G4- 0.2% chitosan with Endovac; and G5- without irrigation. Specimens were obturated (AH Plus) and sectioned in 3 slices per root third. The first slice was used for microhardness and sealer penetration assessments under a laser confocal microscope. The second was utilized in a push-out strength test. The third slice was discarded. Data were analyzed using 2-way ANOVA and Tukey's post hoc test (α&lt;0.05). Failure mode was determined at x40 magnification. Results: Microhardness reduction was more significant in groups G2 and G4 (p&lt;0.05). Sealer penetration through dentin was significantly greater in group G2 (p&lt;0.05). There was no significant difference between groups G1, G3, and G4 (p&gt;0.05). In general, all experimental groups presented similar bond resistance (p&gt;0.05) that significantly differed from the control (p&lt;0.001). Mixed type failures were predominant. Conclusions: In general, 0.2% chitosan and 15% EDTA solutions act in a similar manner with regard to the variables studied. The use of Endovac potentiates the effect of these solutions

Time-dependent effects of chitosan on dentin structures

Complete debridement with smear layer removal are essential measures for achieving a successful outcome of root canal treatment. The aim of this study was to evaluate the effects of chitosan at different concentrations on the removal of the smear layer and on dentin structure after 3 and 5 min of application. Twelve recently extracted maxillary canine teeth were instrumented using the crown-down technique and irrigated with 1% sodium hypochlorite. The specimens were distributed according to the time and concentration of the final irrigating solution: G1: 0.1% chitosan for 3 min; G2: 0.2% chitosan for 3 min; G3: 0.37% chitosan for 3 min; G4: 0.1% chitosan for 5 min; G5: 0.2% chitosan for 5 min; G6: 0.37% chitosan for 5 min. All samples were prepared for SEM analysis. G1 exhibited removal of the smear layer, but not the smear plugs. G2 showed visible and open tubules with slight erosion of the peritubular dentin. Cleaning in G3 was similar to that in G2, however, the erosive effect was greater. There was expansion of the diameter of the tubules in G4; and in G5 and G6, there was severe erosion with deterioration of dentin surface. In conclusion, 0.2% chitosan for 3 min appeared to be efficient for removing the smear layer, causing little erosion of dentin

Database Survey of Anti-Inflammatory Plants in South America: A Review

Inflammation is a complex event linked to tissue damage whether by bacteria, physical trauma, chemical, heat or any other phenomenon. This physiological response is coordinated largely by a variety of chemical mediators that are released from the epithelium, the immunocytes and nerves of the lamina propria. However, if the factor that triggers the inflammation persists, the inflammation can become relentless, leading to an intensification of the lesion. The present work is a literature survey of plant extracts from the South American continent that have been reported to show anti-inflammatory activity. This review refers to 63 bacterial families of which the following stood out: Asteraceae, Fabaceae, Euphorbiaceae, Apocynaceae and Celastraceae, with their countries, parts used, types of extract used, model bioassays, organisms tested and their activity

Microcephaly epidemic related to the Zika virus and living conditions in Recife, Northeast Brazil.

BACKGROUND: Starting in August 2015, there was an increase in the number of cases of neonatal microcephaly in Northeast Brazil. These findings were identified as being an epidemic of microcephaly related to Zika virus (ZIKV) infection. The present study aims to analyse the spatial distribution of microcephaly cases in Recife (2015-2016), which is in Northeast Brazil, and its association with the living conditions in this city. METHODS: This was an ecological study that used data from reported cases of microcephaly from the State Health Department of Pernambuco (August 2015 to July 2016). The basic spatial unit of analysis was the 94 districts of Recife. The case definition of microcephaly was: neonates with a head circumference of less than the cut-off point of -2 standard deviations below the mean value from the established Fenton growth curve. As an indicator of the living conditions of the 94 districts, the percentage of heads of households with an income of less than twice the minimum wage was calculated. The districts were classified into four homogeneous strata using the K-means clustering algorithm. We plotted the locations of each microcephaly case over a layer of living conditions. RESULTS: During the study period, 347 microcephaly cases were reported, of which 142 (40.9%) fulfilled the definition of a microcephaly case. Stratification of the 94 districts resulted in the identification of four strata. The highest stratum in relation to the living conditions presented the lowest prevalence rate of microcephaly, and the overall difference between this rate and the rates of the other strata was statistically significant. The results of the Kruskal-Wallis test demonstrated that there was a strong association between a higher prevalence of microcephaly and poor living conditions. After the first 6 months of the study period, there were no microcephaly cases recorded within the population living in the richest socio-economic strata. CONCLUSION: This study showed that those residing in areas with precarious living conditions had a higher prevalence of microcephaly compared with populations with better living conditions

Influence of periodontal therapy on C-reactive protein level: a systematic review and meta-analysis

The influence of oral infections, especially periodontal disease, on systemic diseases has been extensively discussed in the literature. Because periodontal disease is a persistent infection, it promotes an inflammatory response. C-reactive protein is a marker for inflammatory reactions that is frequently studied, since elevated levels of this protein are related to coronary events. OBJECTIVE: The aim of this study was to investigate the effect of periodontal therapy on reducing the serum levels of C-reactive protein, by means of a systematic review of the literature and meta-analysis. MATERIAL AND METHODS: A systematic review of the English-language literature was conducted in the PUBMED-MEDLINE database, using the key words "periodontal disease", "C-reactive protein", "periodontal therapy" and "periodontal treatment", in accordance with the terms for Medical Subject Headings (MeSH), to evaluate the effect of periodontal therapy on C-reactive protein levels. A qualitative analysis of studies of randomized clinical trial design was performed using CONSORT, with subsequent meta-analysis. RESULTS: The literature search initially retrieved 46 potentially relevant studies available in the databases. From these, in accordance with the inclusion criteria, only 11 were selected, of which only 4 fulfilled the criteria of randomized clinical trial design. According to CONSORT, the studies evaluated generally presented good quality with regard to the criteria analyzed. Through meta-analysis, the reduction in mean levels of C-reactive protein (-0.231; p=0.000) after introducing periodontal treatment was estimated. The result was statistically significant, without evidence of heterogeneity between the studies (p=0.311). CONCLUSIONS: The findings indicated that non-surgical periodontal treatment had a positive effect with regard to reduction of the serum levels of C-reactive protein