Papers by Ana Flávia Barbosa
Australian Endodontic Journal
This study assessed the influence of pH variation on the volumetric change of EndoSequence BC Sea... more This study assessed the influence of pH variation on the volumetric change of EndoSequence BC Sealer compared to AH Plus Jet. Eighteen single‐rooted teeth were uniformly prepared and filled with one of the sealers. After 24‐h storing, samples were scanned in a micro‐CT device. Then, roots were immersed in 20 ml phosphate‐buffered saline (PBS) with pH of 5, 7 or 12 at 37°C for 7 and 30 days and rescanned. Statistical analysis was performed using Shapiro–Wilk's test, one‐way ANOVA and Tukey's or Student's t‐tests (p < 0.05). Differences between sealers were observed only at neutral pH and after 30 days of acidic pH exposure, with a higher loss of EndoSequence (p < 0.05). After 7 days, alkaline pH reduced and increased the volumetric loss of EndoSequence and AH Plus, respectively, compared to neutral pH (p < 0.05). It can be concluded that the pH directly influenced the volumetric change of both tested root canal sealers in different ways.
Brazilian Oral Research
Accumulated hard tissue debris (AHTD) in root canal irregularities may negatively impact adequate... more Accumulated hard tissue debris (AHTD) in root canal irregularities may negatively impact adequate root canal disinfection. In light of this, the efficacy of passive ultrasonic irrigation (PUI) to reduce AHTD has been largely studied in in vitro studies, which have adopted different analytic methods of varying accuracy to determine the extent of AHTD more correctly. Therefore, the aim of this study was to compare how well PUI and non-activated irrigation (NAI) systems perform in reducing AHTD during final irrigation protocols, based exclusively on studies whose analyses used microCT scanning. A systematic search of the studies published up to April 2020 was performed using MeSH terms and free terms, in the following databases: PubMed, Scopus, Web of Science, BVS (Lilacs and BBO) and Embase. The inclusion criteria consisted of laboratory studies that evaluated the amount of AHTD, and compared PUI with NAI protocols using microCT analysis. The risk of bias in the selected studies was assessed critically by two reviewers. A meta-analysis was performed using the RevMan software program (P<0.05), and included studies providing the standardized mean difference (SMD), using a fixed effect model, and adopting a confidence interval of 95%. In all, 3495 studies were identified, three of which met the inclusion criteria. All three were considered as having a low risk of bias. The meta-analysis comparing the ability of PUI and NAI protocols to remove hard tissue debris showed a higher percentage of AHTD reduction (P<0.01) for PUI, with a confidence interval of 1.41 [0.79, 2.02]. The heterogeneity among the studies was 82% (I 2). Considering the limitations of the present study, this systematic review and meta-analysis showed that PUI was more effective than NAI in removing hard tissue debris, based exclusively on studies that used microCT scanning to provide a more precise analysis of the two techniques used. The findings presented in the present study reinforce the concept that PUI can increase residue removal and improve the cleanliness of the root canal in endodontic treatments.
Australian Endodontic Journal
This study assessed the pulp tissue dissolution from isthmus of a two‐rooted maxillary premolar u... more This study assessed the pulp tissue dissolution from isthmus of a two‐rooted maxillary premolar using different final irrigation protocols. After root canal preparation, the surface of the tooth was reduced to an extent that the isthmus could be observed, and 1 mg of pulp tissue was introduced into the isthmus which was covered with a glass slide. Following six groups were tested: syringe and needle; subsonic activation; sonic activation; ultrasonic activation; heating followed by sonic activation; and heating followed by ultrasonic activation. Before and after each experiment a photograph of the isthmus was taken at 30× to register the area of the pulp tissue. Statistical analysis was performed with Kruskal–Wallis and Mann–Whitney tests (P < 0.05). Syringe and needle group showed the lower value of pulp tissue dissolution followed by subsonic irrigation procedures. Pulp tissue dissolution was significantly higher when heating was followed by sonic or ultrasonic activation.
Australian Endodontic Journal
The aim of this study was to evaluate the effect of glycolic acid (GA) and EDTA on dentin mechani... more The aim of this study was to evaluate the effect of glycolic acid (GA) and EDTA on dentin mechanical properties. For the cohesive strength, flexural strength and fracture strength tests, the hourglass of root dentin, dentin sticks and roots standardised to 1 mm thickness were used respectively. ANOVA and Tukey tests were used for statistical analysis (P < 0.05). The results showed that EDTA and GA 17% reduced the cohesive strength values when compared to distilled water (control; P = 0.0022 and P = 0.0016 respectively), whereas the values for GA 10% group were similar to those of the control group (P = 0.093). No statistically significant difference was found among the groups for the flexural strength test (P = 0.1974). Fracture strength test showed that EDTA and GA 17% were statistically similar to each other (P = 0.7694) and statistically inferior to GA 10% (P = 0.0007 and P = 0.0004 respectively). It was concluded that 10% GA showed fewer negative effects on dentin mechanical properties.
Australian Endodontic Journal, 2021
This study evaluated the penetration of the irrigant subject to activation after performing retro... more This study evaluated the penetration of the irrigant subject to activation after performing retro-preparation in endodontic microsurgery. Forty mandibular premolars were prepared and filled. Subsequently, 1 mm from the root apex was cut using a multi-blade bur and the retro-preparation was performed. In group 1, the retro-cavity was cleaned with 2 mL of saline and then with 2 mL of 5.25% NaOCl gel mixed with 0.1% Rhodamine B. In group 2, the retro-cavity was cleaned with 2 mL of saline, 17% EDTA gel was activated ultrasonically for 30 s and 5.25% NaOCl gel was mixed with 0.1% Rhodamine B and activated for 30 s. After 7 days, the roots were cut at 1mm from the apex and the slices were evaluated with confocal laser scanning microscopy. The samples of group 2 showed statistically better results. The activation protocol proposed resulted in enhanced irrigant penetration when compared to the traditional.
International Endodontic Journal, 2021
AimTo evaluate the influence of traditional and conservative access cavity preparations on the re... more AimTo evaluate the influence of traditional and conservative access cavity preparations on the remaining dentine thickness in the coronal third of mesial canals of extracted mandibular molars prepared with reciprocating instruments using micro‐computed tomography as the analytical tool.MethodologySeventy extracted mandibular molars were scanned at a pixel size of 19 μm. From this initial sample, 20 teeth were selected, pair‐matched and distributed into two groups (n = 10) according to the access cavity preparation: traditional (TradAC) or conservative (ConsAC). The root canals were sequentially enlarged with Reciproc Blue R25 (size 25, 0.08v taper) and R40 (size 40, 0.06v taper) instruments. A new scan was performed and the postoperative stacks were coregistered with their respective preoperative datasets. A colour‐coded cross sections of the roots were created and used to identify and measure the smallest dentine thickness related to both MB and ML canals at 1.0‐mm intervals from t...
Microscopy Research and Technique, 2021
A root‐end filling material is required to fill the root‐end cavity without gaps or voids, to pre... more A root‐end filling material is required to fill the root‐end cavity without gaps or voids, to prevent root canal reinfection and to provide periapical healing. Thus, this study evaluated the volume of marginal gaps and voids of three root‐end filling materials using microcomputed tomography (micro‐CT). Thirty maxillary incisors were prepared and filled with gutta‐percha and endodontic sealer. The specimens were scanned using micro‐CT and distributed into three groups (n = 10): White MTA, MTA Repair HP, and Bio‐C Repair. The root tips were resected at 90° to the longitudinal axis and the cavity (3 mm depth) was prepared with an ultrasonic tip. The materials were handled, and the cavities were filled. The specimens were rescanned and the percentual volume of gaps and voids were analyzed. The data were analyzed using Kruskal–Wallis and Dunn tests (p < .05). No statistical difference was found in the percentage of gaps among the tested materials (p > .05). White MTA presented less voids than Bio‐C and MTA Repair HP (p < .05). The materials presented a similar percentual volume of gaps and White MTA presented less voids than other tested materials.
Restorative Dentistry & Endodontics, 2021
Objectives: To evaluate the fracture incidence of Reciproc R25 instruments (VDW) used during non-... more Objectives: To evaluate the fracture incidence of Reciproc R25 instruments (VDW) used during non-surgical root canal retreatments performed by students in a postgraduate endodontic program. Materials and Methods: From the analysis of clinical record cards and periapical radiographs of root canal retreatments performed by postgraduate students using the Reciproc R25, a total of 1,016 teeth (2,544 root canals) were selected. The instruments were discarded after a single use. The general incidence of instrument fractures and its frequency was analyzed considering the group of teeth and the root thirds where the fractures occurred. Statistical analysis was performed using the χ 2 test (p < 0.01). Results: Seven instruments were separated during the procedures. The percentage of fracture in relation to the number of instrumented canals was 0.27% and 0.68% in relation to the number of instrumented teeth. Four fractures occurred in maxillary molars, 1 in a mandibular molar, 1 in a mandibular premolar and 1 in a maxillary incisor. A greater number of fractures was observed in molars when compared with the number of fractures observed in the other dental groups (p < 0.01). Considering all of the instrument fractures, 71.43% were located in the apical third and 28.57% in the middle third (p < 0.01). One instrument fragment was removed, one bypassed, while in 5 cases, the instrument fragment remained inside the root canal. Conclusions: The use of Reciproc R25 instruments in root canal retreatments carried out by postgraduate students was associated with a low incidence of fractures.
Dental Materials, 2021
OBJECTIVE The aim of this study was to evaluate the influence of the incorporation of chlorhexidi... more OBJECTIVE The aim of this study was to evaluate the influence of the incorporation of chlorhexidine-hexametaphosphate nanoparticles (CHX-HMP NPs) on antibacterial, cytotoxic and physicochemical properties of AH Plus (AH), MTA Fillapex (MTA) and Pulp Canal Sealer (PCS). METHODS The NPs were synthesized and characterized by Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), zeta potential, Atomic Force Microscopy (AFM) and Energy-Dispersive X-ray Spectroscopy (EDS). The incorporation was made by weight, 2% and 5% of NPs. The antimicrobial activity, cytotoxicity, flow, radiopacity, setting time, solubility and pH were evaluated. The statistical analysis was performed by two-way analysis of variance test and Tukey post hoc test (P < 0.05). RESULTS SEM analysis showed the tendency for CHX-HMP NPs to cluster, the effective mean diameter measured by DLS: 169.39 nm and the zeta potential: -10.18 mV. The NPs were individually measured by AFM: 22.99-52.75 nm. EDS analysis identified the presence of C, N, O, Na, P, Cl. After incorporation: The Direct Contact Test showed an increase in the antimicrobial action of AH, PCS and MTA; the sealers showed a decrease in flow and at 24 h of immersion also an increase in solubility, but did not affect the radiopacity of the samples; AH setting time increased and MTA did not reach setting under any of the conditions tested. All samples showed a decrease in pH value as the immersion time progressed. SIGNIFICANCE The incorporation of NPs can improve the antimicrobial performance of endodontic sealers without impairing other biological and physicochemical properties.
A clencia, para o filósofo moderno, herdeiro do !luminismo, era vista como algo auto-referente, o... more A clencia, para o filósofo moderno, herdeiro do !luminismo, era vista como algo auto-referente, ou seja, existia e se renovava incessantemente com base em si mesma. Em outras palavras, era vista como atividade "nobre", "desinteressada", sem finalidade preestabelecida, sendo que sua função primordial era romper com o mundo das "trevas" mundo do senso comum e das crenças tradicionais, . , contribuindo assim para o desenvolvimento moral e espiritual da nação.
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Papers by Ana Flávia Barbosa