W.T. FELIPPE

Federal University of Santa Catarina, Nossa Senhora do Destêrro, Santa Catarina, Brazil

Are you W.T. FELIPPE?

Claim your profile

Publications (54)87.16 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Introduction: Disruption of the matrix of endodontic biofilms will aid in their removal from a root canal. Therefore, the aim of this study was to investigate the efficacy of EDTA and a modified salt solution (MSS) to detach bacteria from biofilms. Methods: Forty-eight-hour-old Enterococcus faecalis biofilms were grown on glass coverslips and then treated for 1 hour by immersion in 17% EDTA or MSS. Phosphate-buffered saline served as a negative control. Then, residual biofilm cells on the substrate and the detached cells in the supernatant were collected. Viability was verified by the colony-forming unit (CFU) counting method. Propidium monoazide (PMA) treatment in conjunction with quantitative polymerase chain reaction (qPCR) was also performed to detect the presence of E. faecalis 16S ribonucleic RNA genes. Data were analyzed using 1-way analysis of variance and Tukey or Kruskal-Wallis and Dunn tests. The Pearson R test evaluated the correlation between results from CFU and PMA (α = 5%). Results: qPCR showed that EDTA detached 99% of biofilm cells, and MSS detached 94% of biofilm cells (both P < .001). In contrast to EDTA, MSS was highly antimicrobial. The treatment promoted an ample log 7 reduction of the attached cells (P < .001), and almost no live cells were detected in the supernatant (P < .001). Positive correlations between CFU and qPCR with PMA were observed (r = 0.959 and r = 0.729). Conclusions: EDTA detached cells in biofilms with a minor antimicrobial effect. Besides a great antimicrobial effect, MSS also detached biofilm cells. These dispersals of biofilms give insights into new endodontic biofilm removal strategies.
    Full-text · Article · Dec 2015 · Journal of endodontics
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Aim: To evaluate nanoparticulate calcium carbonate (NPCC) using transmission electron microscopy and the effects of NPCC addition to MTA in regards to the setting time, dimensional change, compressive strength, solubility and pH. Methodology: The experimental groups were G1 (MTA), G2 (MTA with 5% NPCC) and G3 (MTA with 10% NPCC). The tests followed ISO and ADA standards. The specimens in the dimensional change and compressive strength tests were measured immediately after setting, after 24 hours, and after 30 days. In the solubility test, rings filled with cement were weighed after setting and after 30 days. The pH was measured after 24 hours and 30 days. The data were analyzed with the ANOVA, Tukey's and Kruskal-Wallis tests (α=5%). Results: The setting time was reduced (p<0.05) in samples from G2 and G3 compared to G1. After 24 hours, the dimensional change was similar among the groups, and after 30 days, G2 showed less alteration than G1 and G3. There was a difference in the compressive strength (p<0.001) after 24 hours and 30 days (G1>G2>G3). The solubility test revealed a difference among the groups when the specimens were hydrated: G2>G1>G3 and dehydrated: G3>G2>G1. The pH of the groups was similar at 24 hours with higher values in each group after 30 days (p<0.05), and G2 and G3 had similar mean pH values but both were higher than G1. Conclusions: Nanoparticulate calcium carbonate had a cubic morphology with few impurities. The addition of nanoparticulate calcium carbonate to the MTA accelerated the setting time, decreased compressive strength, and after 30 days, resulted in lower dimensional change (G2), higher solubility and a higher pH. This article is protected by copyright. All rights reserved.
    Full-text · Article · Dec 2015 · International Endodontic Journal
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Florid cemento-osseous dysplasia (FCOD) belongs to the group of fibro-osseous lesions in which normal bone is replaced by fibrous connective tissue and calcified cementum tissue of the avascular type. Among the various types of fibro-osseous lesions, FCOD is 1 of the most commonly encountered diseases in clinical practice and may involve 3 or 4 of the quadrants. FCOD is located in the periapical regions of teeth, and the lesions are predominantly radiolucent (osteolytic phase), become mixed over time (cementoblast phase), and ultimately become radiopaque (osteogenic phase) with a thin radiolucent peripheral halo. The characteristics of FCOD in the initial stages are similar to those of periapical lesions of inflammatory origin, which may lead to misdiagnosis. A 38-year-old woman sought dental care because of complaints of pain on the right side of her face. A clinical examination revealed no marked alterations; a panoramic radiograph was therefore requested and revealed the presence of radiolucent lesions associated with the periapical regions of some of the lower teeth. Thus, the professional referred the patient for endodontic treatment of the associated teeth with the justification that the lesions were of endodontic origin. However, the endodontist found that the teeth responded positively to a sensitivity test. The initial diagnosis could have resulted in unnecessary root canal treatment, but after careful clinical, radiographic, and tomographic assessments by different professionals, FCOD was diagnosed, conservatively treated, and regularly monitored. It is important that dentists have a basic knowledge of the various injuries that affect the jaw bones to prevent errors in diagnosis and treatment and to promote oral health.
    Full-text · Article · Sep 2015 · Journal of endodontics
  • Josiane de Almeida · Andrea L Pimenta · Wilson T Felippe
    [Show abstract] [Hide abstract]
    ABSTRACT: This study evaluated the influence of the exposure of mineral trioxide aggregate (MTA) - with and without calcium chloride (CaCl2) -to phosphate-buffered saline (PBS) on apical microleakage. Sixty root segments were divided into 4 experimental groups (n=15). Apical cavities were filled with MTA with or without CaCl2, and the root canals dressed with a moistened cotton pellet or PBS: 1) MTA/cotton pellet; 2) MTA/PBS; 3) MTA+ 10%CaCl2/cotton pellet; 4) MTA+10%CaCl2/PBS. After 2 months, E. faecalis penetration was analyzed along the apical plugs. Samples were observed weekly for 70 days, and leakage was detected by turbidity of the medium in contact with the root segment. Teeth in the control groups (n=2) were either made completely impermeable or kept without an apical plug. The Kaplan-Meier method was used to analyze survival and the Logrank test was used to compare the survival curves (p<0.05). All specimens in the positive control group showed evidence of leakage within 24h, while none in the negative control group showed leakage up to 70 days. There was no statistically significant difference among the experimental groups (p=0.102). The use of PBS as intracanal dressing may improve MTA sealing ability, but cannot prevent bacterial leakage. The addition of CaCl2 to the MTA did not improve MTA sealing ability.
    No preview · Article · Sep 2015 · Acta odontológica latinoamericana: AOL
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Regenerative endodontic treatment is a new and promising approach to manage immature teeth with necrotic pulps and apical periodontitis. The use of scaffolds is essential to treatment success, but many materials are difficult to acquire and have a high cost. This study assessed tissue repair in immature dog teeth with necrotic pulps and apical periodontitis after using a gelatin-based scaffold (Gelfoam; Pharmacia & Upjohn Co, Kalamazoo, MI). Apical periodontitis was induced in 20 immature dog teeth. After disinfection with triple antibiotic paste for 2 weeks, canals were irrigated, dried, and filled with a blood clot alone (10 teeth) or combined with Gelfoam (10 teeth). Another 10 teeth were used as negative controls (no intervention). After 7 months, the dogs were euthanized. Histologic sections were stained with hematoxylin-eosin and analyzed in relation to tissue repair. Categoric data were analyzed using the Fisher exact test (P < .05), numeric data (histomorphometric analysis), and the Mann-Whitney U test. Histologic analysis revealed a higher percentage of roots with new cementumlike mineralized tissue and connective tissue inside the canal in the blood clot + Gelfoam group (P < .001). Histomorphometric analysis showed a higher area of mineralized tissue in the same group (P = .029). Apical extension of root and inflammation were similar between the experimental groups. The new tissue formed onto canal walls and in the root canal space showed characteristics of cementum and periodontal ligament, respectively. The use of a gelatin-based scaffold (Gelfoam) combined with a blood clot improved repair in immature dog teeth with apical periodontitis subjected to regenerative endodontic treatment. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
    Full-text · Article · Aug 2015 · Journal of endodontics
  • [Show abstract] [Hide abstract]
    ABSTRACT: The objective of this study was to use pulse oximetry to measure oxygen saturation in permanent maxillary central incisors with normal pulp in 2 different age groups: children/adolescents and adults. Blood oxygen saturation levels were measured using a pulse oximeter in 110 maxillary central incisors of 57 individuals, in 1 of 2 possible age bands, as follows: 28 children/adolescents (7-13 years old) and 29 adults (22-36 years old). The following factors were also analyzed: (1) heart rate (beats/min); (2) oxygen saturation rate measured at the patient's index finger, also using a pulse oximeter; (3) tooth crown dimensions; and (4) the time taken by the oximeter to provide a reading. The mean oxygen saturation level in normal central incisors was higher among children/adolescents (84.35%) than adults (77.88%, P = .003). Oxygen saturation rates measured at the patients' fingers were not correlated with saturation obtained at the teeth (r = 0.10). There was no correlation between oxygen saturation readings and tooth dimensions (buccal surface area), heart rate, or oximeter reading time (P > .05). Oxygen saturation values measured in maxillary central incisors using a pulse oximeter revealed differences between children/adolescents and adults, showing that children/adolescents have higher oxygen saturation levels. There was no correlation between oxygen saturation levels in patients' fingers and values from their teeth or between oxygen saturation readings from central incisors and tooth dimensions (buccal surface), heart rate, or oximeter reading time. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
    No preview · Article · Jun 2015 · Journal of endodontics
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Aim: To analyze the influence of exposure and time of exposure to phosphate buffered saline (PBS) on the push-out bond strength (BS) of Biodentine to dentine. Methods: Eighty 2-mm-thick dentin discs were obtained from transversal sections of human teeth roots. The space of the canal was enlarged using #2-#5 Gates-Glidden burs to obtain 1.3-mm-diameter standardized cavities. The discs were immersed in 17% EDTA followed by 1% NaOCl and dried. The spaces of the canals were filled with Biodentine and the samples were divided into 2 groups (n=40) according to the storage: G1: exposure to moistened cotton pellet; G2: exposure to PBS. After 30 min, 1, 3 and 28 days, 10 samples of each group were subjected to the push-out test. Data were analyzed using ANOVA and Tukey test (p < 0.05). Results: The specimens exposed to PBS had lower BS (p < 0.05), except for the 1-day period (p = 0.6017). In specimens of Group 1 the BS increased up to 3 days (p < 0.05). In specimens in Group 2, the BS increased from 30 min to 1 day (p < 0.0001) and remained stable up to 3 days (p = 0.9876). At 28 days, a significant decrease was observed in the BS values of both groups (p < 0.05). Conclusions: The exposure of Biodentine to PBS led to lower BS values. In general, the BS increased gradually up to 3 days and reduced at 28 days.
    Full-text · Article · Jun 2015 · Brazilian Journal of Oral Sciences
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The objective of this study was to evaluate the efficacy of passive ultrasonic irrigation (PUI) with 17% EDTA and 1% NaOCl solutions on smear layer removal. Root canal preparations of 32 human teeth were performed with the ProTaper system. Next, they were longitudinally fractured to permit quantitation of smear layer creation from the cervical, middle, and apical thirds of the roots by using scanning electron microscopy. After reassembling the fractured tooth halves, they were divided into 4 groups according to different final irrigation protocols: group1, EDTA + NaOCl; group 2, EDTA with PUI + NaOCl; group 3, EDTA + NaOCl with PUI; and group 4, EDTA + NaOCl, both with PUI. After irrigation, the tooth halves were separated to permit imaging the same areas by scanning electron microscopy, and a percentage of opened dentinal tubules in irrigated areas as a percent of the total area was obtained. The results were submitted to Kruskal-Wallis, analysis of variance, and Bonferroni tests (α = 0.05). The cervical third of the samples from all groups showed higher percentage of smear layer removal and open dentinal tubule areas, followed by the middle and apical thirds. Among the irrigation groups, there were statistically significant differences in cervical third between group 2 and group 4 samples, with the highest and lowest percentage of smear layer removal, respectively. PUI by using 1% NaOCl and ultrasonic tip placed within 1 mm of the apical foramen did not show higher efficacy in smear layer removal compared with conventional irrigation. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
    Full-text · Article · May 2015 · Journal of endodontics
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This study evaluated the bond strength (BS) and the adhesive interface of four endodontic sealers to root canal dentine, before, and after immersion in phosphate buffered saline (PBS) to simulate an in vivo environment. Eighty roots were instrumented using ProTaper rotatory files, under irrigation with 17% EDTA and 1% NaOCl. Posteriorly were divided into four groups (n = 20) according to the sealer used: Endofill, AH Plus, Sealapex, and MTA Fillapex. Each group was divided into two subgroups (n = 10) and stored at 37°C immersed in water for 7 days and in PBS for 60 days. From each subgroup, 1 mm thick sections were obtained. One section of each region (coronal, middle, and apical) was submitted to the push-out test and failures were observed. Twelve sections of each subgroup (four from each region) were evaluated under SEM. Three-way ANOVA evaluation for BS showed significant differences between groups and regions (P < 0.0001), but not between subgroups (P > 0.05). AH Plus had significantly higher BS than the others sealers, regardless of the analyzed subgroup (Tukey's test, P < 0.5). The most common failures were adhesive to dentine and cohesive of the sealer. The SEM evaluation (Kruskal–Wallis, Mann–Whitney) showed homogeneous adhesive interface formed and sealer tags in all groups with significant statistical differences with AH Plus, regardless of PBS immersion. AH Plus was superior to the other sealers for both BS and quality of interface formation. Immersion in PBS did not interfere on BS or adhesive interface of the sealers tested. Microsc. Res. Tech., 2014. © 2014 Wiley Periodicals, Inc.
    Full-text · Article · Dec 2014 · Microscopy Research and Technique
  • [Show abstract] [Hide abstract]
    ABSTRACT: Introduction In individuals with periodontal disease, dental pulp status should be determined before a treatment plan is made. Pulse oximeters are promising diagnostic tools to evaluate pulp vascularization. This study used pulse oximetry to determine the level of oxygen saturation in dental pulp of intact permanent teeth with periodontal attachment loss (PAL) and gingival recession (GR) and to evaluate the correlation between periodontal disease and level of oxygen saturation in the pulp. Methods This study included 67 anterior teeth of 35 patients; all teeth showed intact crowns, PAL, a periodontal pocket (PP), and GR. The teeth underwent periodontal examination, cold and electric pulp testing, and pulse oximetry measurements. The Pearson correlation coefficient and a linear regression coefficient were calculated to evaluate the degree of correlation between periodontal disease markers (PAL, PP, and GR) and the level of oxygen saturation in dental pulp. These tests also evaluated possible associations between oxygen saturation and cold and electric pulp testing. Results PAL, PP, and GR had negative correlations with oxygen saturation in dental pulp. Conversely, no statistically significant association was found between oxygen saturation in dental pulp and the response to electric sensibility testing. Conclusions Oxygen saturation was lower in the pulp of permanent teeth with PAL, PP, and GR, indicating that periodontal disease correlates with the level of oxygen saturation in the pulp.
    No preview · Article · Oct 2014 · Journal of Endodontics
  • [Show abstract] [Hide abstract]
    ABSTRACT: Introduction Pulse oximetry is a noninvasive method for assessing vascular health based on oxygen saturation level. The method has recently also been used to assess dental pulp vitality, but a median oxygen saturation level suggestive of normal pulp physiology has not been determined. The objective of this study was to make a critical analysis of the published research to establish the median oxygen saturation for the diagnosis of normal dental pulps in maxillary anterior permanent teeth using pulse oximetry. Methods Studies reporting on the use of pulse oximeters to determine oxygen saturation in dental pulps were retrieved using the MEDLINE, Scientific Electronic Library Online, and Cochrane Central Register of Controlled Trials databases plus a manual search of relevant references cited by selected articles. Different combinations of the terms “oximetry,” “oximeter,” “pulp,” “dental,” and “dentistry” were used in the search. Statistical analysis was performed for each group of teeth (central incisors, lateral incisors, and canines) using R statistical software (US EPA ORD NHEERL, Corvallis, OR) and a random effects model (P < .0001) with an I2 of 99%. Results Of the 295 articles found, only 6 met the inclusion criteria (472 teeth). Of these, the number of articles included in each analysis (according to tooth group) was as follows: all 6 studies (288 teeth) for central incisors at a median oxygen saturation of 87.73%, 3 studies (90 teeth) for lateral incisors at a median oxygen saturation of 87.24%, and 4 studies (94 teeth) for canines at a median oxygen saturation of 87.26%. Conclusions The median oxygen saturation in normal dental pulps of permanent central incisors, lateral incisors, and canines was higher than 87%.
    No preview · Article · Aug 2014 · Journal of Endodontics
  • Source

    Full-text · Dataset · Dec 2013
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: AimTo evaluate connective tissue reactions to iRoot SP (Innovative Bioceramics, Vancouver, BC, Canada), mineral trioxide aggregate (MTA) Fillapex (FLPX) (Angelus Soluções Odontológicas, Londrina, Brazil), DiaRoot Bioaggregate (DiaDent Group International, Burnaby, BC, Canada) and white MTA (Angelus, Londrina, Brazil) in Wistar rats. MethodologyA total of 128 dentine tubes filled with the materials and 32 empty tubes (control) were implanted into 32 rats. After 7, 15, 30 and 90 days (n = 8 per period), the animals were euthanized, and the tissues were processed for histological evaluation using haematoxylin-eosin (H&E) and Von Kossa (VK) staining. Observations were made for cellular inflammatory components and the presence of multinucleated giant cells (MNGC), macrophages and tissue necrosis. Data were analysed by Fisher's exact and Kruskal–Wallis tests (P < 0.05). ResultsIn all experimental periods, MTA FLPX and iRoot SP scored higher than the other groups for the variable macrophages (P < 0.05). After 30- and 90-day experimental periods, MTA FLPX scored higher than the other groups for the variable MNGC (P < 0.05). After 90 days, the only group that exhibited samples with severe inflammatory response was MTA FLPX. VK positivity was observed in areas of necrosis in all groups, except in the control group. Conclusions The materials were considered biologically acceptable except MTA FLPX, which remained toxic to subcutaneous tissue even after 90 days.
    Full-text · Article · Nov 2013 · International Endodontic Journal
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to evaluate the influence of exposure of the mineral trioxide aggregate (MTA) - with and without calcium chloride (CaCl2) - to phosphate-buffered saline (PBS) on the apical microleakage using a glucose leakage system. Sixty root segments were randomly divided into 4 experimental groups (n=15). After resecting the apical segments and enlarging the canals with Gates-Glidden drills, the apical cavities were filled with MTA with or without CaCl2 and the root canals were dressed with a moistened cotton pellet or PBS, as follows: 1) MTA/cotton pellet; 2) MTA/PBS; 3) MTA+10%CaCl2/cotton pellet; 4) MTA+10%CaCl2/PBS. All root segments were introduced in floral foams moistened with PBS. After 2 months, all root segments were prepared to evaluate the glucose leakage along the apical plugs. The amount of glucose leakage was measured following an enzymatic reaction and quantified by a spectrophotometer. Four roots were used as controls. The data were analyzed using Kruskal-Wallis and Mann-Whitney tests (p<0.05). There were no differences between groups 1 and 2 (p>0.05), and 3 and 4 (p>0.05). The addition of CaCl2 to the MTA significantly decreased its sealing ability (p<0.05). The interaction with PBS did not improve the MTA sealing ability. The addition of CaCl2 to the MTA negatively influenced the apical seal.
    Full-text · Article · Aug 2013 · Journal of applied oral science: revista FOB
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To analyse the influence of exposure of mineral trioxide aggregate (MTA) with and without calcium chloride (CaCl2 ) to phosphate-buffered saline (PBS) on the push-out bond strength, over different experimental periods. One hundred and twenty dentine discs with standardized cavities were filled with MTA with and without 10% CaCl2 . The specimens were randomly divided as follows (n = 30): (G1) MTA in contact with a moistened cotton pellet, (G2) MTA immersed in PBS, (G3) MTA + CaCl2 in contact with a moistened cotton pellet and (G4) MTA + CaCl2 immersed in PBS. The samples were stored for 3, 28 and 60 days. The bond strengths were measured with the Instron Testing machine. Data were analysed using the three-way anova and Tukey test (P < 0.05). In general, the samples of MTA with and without CaCl2 , exposed to PBS, had higher bond strength values in all study periods (P < 0.05). Analysis of the influence of addition of CaCl2 to MTA (G1 × G3) evidenced significant differences in bond strength in the different periods (P < 0.05). The exposure of MTA to PBS positively influenced the push-out bond strength, whereas the addition of CaCl2 had a negative influence.
    Full-text · Article · Jul 2013 · International Endodontic Journal
  • [Show abstract] [Hide abstract]
    ABSTRACT: Many articles demonstrated that Passive Ultrassonic Irrigation (PUI) improves the cleaning and the smear layer removal. However no article has yet shown if the PUI influences on hydroxil ions (OH-) diffusion on dentin. Objective: The aim of this study was to evaluate the PUI effect on OH- diffusion arising from calcium hydroxide paste among root dentin. Methods: 50 humans teeth were endodontically prepared. The cement layer was removed and the root surface was washed with EDTA and NaOCl. The cementoenamel junction and the apical portion of each root was covered. 4 different protocols for final irrigation were employed (n=10): G1 - final irrigation with EDTA + NaOCl, G2 - final irrigation with EDTA + PUI + NaOCl, G3 – final irrigation with EDTA + NaOCl + PUI and G4 – final irrigation with EDTA + NaOCl both with PUI activation. 5 teeth received only distilled water as final solution (G5) and other five were irrigated with distilled water + PUI (G6) working was control groups. The root canal was then dried and filled with CH. The specimens were individually kept in plastic vials containing distilled water (10mL) with a known pH. After 7, 15, and 21 days the pH from the specimens distilled water was verified. This values were recorded and compared by using ANOVA and Tukey’s test was used to individuals comparisons (α=0.05). Results: No statistically significant difference was observed between the groups (p=0.1224). But it was observed among the different periods (p<0.0001). In the 15 and 21 days period was more OH- diffusion when compared to the 7 days analysis. Conclusion: PUI did not influence on OH- diffusion among radicular dentin. When CH is employed as an intracanal medication it is necessary at least 15 days for the paste to promote a proper alcalinization of the dentin.
    No preview · Conference Paper · Mar 2013
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: : The aim of this ex vivo study was to evaluate the effects of NaOCl and EDTA solutions, prior to root canal dressing with calcium hydroxide, on compressive strength of root dentin. Method: Forty-eight roots with single and straight canals were used. The endodontic treatment was conducted by the crown-down technique, and canals were irrigated with 2 ml of 0,9 % NaCl between each file or drill. Further, specimens were randomly divided into four groups (n = 12), according to the irrigating solution used: group 1 (control), 0.9% NaCl; group 2, 1% NaOCl; group 3, 17% EDTA; group 4, 1% NaOCl and 17% EDTA. The total time of irrigation in each group was 40 min, and every 10 min the tested solution was renewed. In group 4, the time was equally divided (alternating solutions every 10 min). Further, each root canal was dry and filled with calcium hydroxide paste. After X-rays to confirm the completion, each canal was sealed and stored at 37º C for 30 days. After this period, the roots were cut 1 mm below the cement-enamel junction and 6 mm apically from this cut, in order to obtain 6 mm-length cylinders. The compressive strength test was conducted in an Instron machine with a crosshead speed of 1mm/min. Result: The data recorded at fracture (MPa) were analyzed by ANOVA and Tukey test (α = 5%) and it was found that there was statistically significant difference between group 2, irrigated with NaOCl, and group 4, irrigated with EDTA and NaOCl. Group 2 had a mean compressive strength superior to that of Group 4. Conclusion: The root canal irrigation with 17% EDTA followed by 1% NaOCl promote a significant reduction of root dentin resistance observed after 30 days of calcium hydroxide dressing.
    No preview · Conference Paper · Mar 2013
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: To evaluate ex vivo the effects of immersion in phosphate buffer solution (PBS) in bond strength (BS) and adhesive interface formation between endodontic sealers and root canal dentin. Methods: Eighty 16-mm long roots had their canals submitted to biomechanical preparation. After the final irrigation with EDTA and NaOCl, the canals were randomly divided into four groups (n = 20) according to the sealer used in obturation: Endofill (G1), AH Plus (G2), Sealapex (G3) and MTA Fillapex (G4). Half of the specimens of each group was tested after 07 days of immersion in water (Period A) and the other half after 60 days in PBS (period B). Two cross-sections of 1 mm thickness for each region (coronal, middle and apical) of the root were obtained. One slice per region was used to push-out test and the other one was prepared for interface analysis in scanning electron microscopy (SEM). Results: Three-way analysis of variance (α = 0.05) indicated statistically significant difference among the groups and the regions (p <0.0001), but not among periods. AH Plus (G1) had higher BS than the other sealers, regardless of the period analyzed (p <0.5). Adhesive failures were more commonly observed in the G1 Group (Endofill), and cohesive failures in the other groups. SEM analysis showed In both periods A and B, homogeneous adhesive interface and the presence of many tags when the AH Plus sealer was used. After 60 days of immersion in PBS it was observed greater depth of sealer penetration into dentinal tubules,only when Sealapex and MTA Fillapex were used. Conclusion: The immersion in PBS did not increase the bond strength to dentin of the tested sealers, although after this period the SEM analysis showed more homogeneous adhesive interface.
    No preview · Conference Paper · Jun 2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: Mineral Trioxide Aggregate (MTA) has as radiopacifier bismuth oxide (Bi2O3), which has received criticism for not taking part of the material setting and for make it more porous. Portland cement has similar composition and lower price as compared to MTA and because of that, Portland cement has replaced MTA in many researches. This study aimed to evaluate the solubility and the disintegration of Portland cement with different concentrations of Bi2O3 (0, 10, 15, 20 e 30%). Method: Twelve teflon rings with 4 mm thickness and a 12 mm diameter were filled with cement. After setting, the samples were weighed (initial hidrated weight = PH0) and after 24 h in a dissecator, the samples were again weighed (initial dehydrated weight = PD0). Then the samples were divided and immersed in deionized water for 7 and 30 days. After those periods, the same procedures were performed and new weights were obtained (PH7d, PD7d, PH30d e PD30d). The solubility and disintegration of the cements was measured by the loss of mass identified by the weight of each sample, expressed as percentage of weight lost when compared to the original weight. For statistical analysis it was employed the two-way ANOVA test, in each period, and the Tukey HSD to indicate the significant differences (α=5%). It was not observed disintegration of the cements. Result: There was a difference between the groups in the 7 days analysis (hidrated and dehydrated) and between the periods for pure Portland cement when weighed dehydrated (p<0,05). Conclusion: Although there was statistical difference in the solubility of the groups at 7 days, all showed the same behavior after 30 days of storage in water.
    No preview · Conference Paper · Jun 2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: The aim of this study was to evaluate the coronal leakage in root canals filled with gutta-percha and AH Plus and MTA FILLAPEX. Method: After accessing, measuring and cleaning of the 36 single-rooted premolars root canals, the instrumentation was performed with the ProTaper system, until to instrument F4 under irrigation with 1%. sodium hypochlorite solution Thirty teeth were randomly divided in two experimental groups (n = 15) according to the sealer used: G1: MTA FILLAPEX and G2: AH Plus. After obturation, with ProTaper F4 cones, the teeth were kept at 37 °C for 07 days. Six teeth were used as positive control group (n = 3) and negative control group (n = 3). The infiltration test was realized with dye ink under a pressure of 60 kPa for 8 min. After diaphanization, the dye penetration was evaluated by root thirds. Result: There was infiltration of 8 and 7 samples of G1 and G2, respectively. In any sample of the G2, the dye reached the apical third, being restricted to the cervical and middle thirds. In four samples of G1, the dye was visualized in the apical third. Evaluating the total infiltration, the χ² test and Fisher's exact test revealed no significant difference between groups 1 and 2. When the dye penetration was evaluated by thirds, the proportions test showed that, for the apical third, G12 were significantly different (p = 0.0317). Conclusion: It was concluded that the two sealers allowed, similarly, the dye leakage in the cervical and middle thirds of the root. When considering infiltration to the apical third, the MTA FILLAPEX showed a lower quality of sealing.
    No preview · Conference Paper · Jun 2012