RESUMEN

This study aimed to evaluate the effects of sodium hypochlorite (NaOCl), chlorhexidine (CHX), and the glycolic extract of propolis (GEP) as endodontic irrigants and of calcium hydroxide [Ca(OH)2], CHX, or Ca(OH)2 + CHX as intracanal medications on the capacity of the lipoteichoic acid (LTA) of Enterococcus faecalis in macrophages' proinflammatory cytokines production. Freshly extracted 108 human single-rooted teeth were used in this study. The LTA of E. faecalis was standardized in double-distilled pyrogen-free water (250 µg/mL) and inoculated into the specimens subdivided into nine subgroups (n = 12). Cultures of murine macrophages (RAW 264.7) were treated with 30 µL of each sample collected from root canals and incubated (37 °C, 5% CO2) for 24 h. Lastly, anti-TNF-α, anti-IL-6, anti-IP-10, anti-MIP-1α, anti-G-CSF, and anti-IL-1ß DuoSet kits were used to perform an ELISA assay. Data were analyzed using one-way ANOVA and Tukey test (p ≥ 0.05). It was found that 1% NaOCl was the most effective irrigant in reducing the capacity of LTA in cytokines production, followed by 12% GEP and 2% CHX, respectively. Ca(OH)2 + CHX presented the best results when associated with NaOCl or GEP. Thus, NaOCl or GEP associated with Ca(OH)2 + CHX were effective in reducing the capacity of LTA in different macrophages pro-inflammatory cytokines production.

RESUMEN

AIM: To evaluate the effect of systemic administration of propranolol on the severity of apical periodontitis (AP) in chronically stressed rats. METHODOLOGY: Twenty-four 70-day-old male Wistar rats (Rattus norvegicus, albinus) were distributed into three groups (n = 8): rats with AP without stressful conditions (AP-Control), rats with AP and submitted to a chronic unpredictable stress (CUS) protocol (AP + S) and rats with AP and submitted to a CUS protocol treated with propranolol (AP + S + PRO). Stress procedures were applied daily until the end of the experiment. After 3 weeks of CUS, AP was induced in all groups by exposing the pulpal tissue of mandibular and maxillary first molars to the oral environment. Propranolol treatment was administered orally once a day for the entire period of the experiment. Rats were sacrificed at 42 days, and the blood was collected for stress biomarkers serum dosage by multiplex assay. Mandibles were removed and submitted to microtomography and histopathological analyses. Periapical tissue surrounding the upper first molar was homogenized and subjected to RT-PCR analysis to evaluate the mRNA expression of RANKL, TRAP and OPG. Parametric data were assessed using one-way ANOVA followed by Tukey's test while the nonparametric data were analysed by the Kruskal-Wallis followed by Dunn's test. Significance level was set at 5% (p < .05) for all assessed parameters. RESULTS: Micro-CT revealed statistically significant differences in bone resorption which was greater in the AP + S group (p < .05), but no differences were observed between the Control and AP + S + PRO groups (p > .05). The AP + S + PRO group had a lower intensity and extent of inflammatory infiltrate compared to the AP + S group with smaller areas of bone loss (p < 0.05). The gene expression of RANKL and TRAP was significantly higher in the stressed group AP + S compared to the control group (p < .05), and a significantly higher OPG expression was observed in AP + S + PRO compared to the AP + S group (p < .05). CONCLUSIONS: Oral administration of propranolol had a significant effect on the AP severity in stressed rats, suggesting an anti-inflammatory effect and a protective role on bone resorption of AP in stressed animals. Further research is necessary to fully comprehend the underlying mechanisms.

RESUMEN

Radiotherapy (RT) is a common treatment for head and neck tumors. However, it causes several physical and behavioral side effects, and no study has assessed the emotional effects in rats. Therefore, the present study evaluated the influence of head and neck RT on the behavior and body weight gain in Wistar rats. Fifty-four male Wistar rats were allocated into six groups (n = 9) according to the irradiation dose, which was applied at the first day of the experiment: RT-7.5 (single dose of 7.5 Gy); RT-10 (single dose of 10 Gy); RT-15 (single dose of 15 Gy); RT-30 (single dose of 30 Gy); Control (without RT). The animals were irradiated in the region of the right face, and behavioral tests and weighing were performed on days one, seven, and 28. The open field and Y-maze tests were undertaken to analyze the animal's behavior. The dose of 30 Gy was lethal when applied to the head and neck region. The irradiated animals had less weight gain when compared to the control ones, but there was no statistical difference. In the open field and Y-maze tests, lower mobility of animals in the RT groups was observed both on day seven and at the end of the experiment (day 28) when compared to the control rats (p < 0.05). It was possible to conclude that the different doses of radiation induced depressive behavior in the animals, and that the weight gain tended to be lower in the irradiated groups, however, without statistical difference.

Asunto(s)

Neoplasias de Cabeza y Cuello , Masculino , Ratas , Animales , Ratas Wistar , Relación Dosis-Respuesta en la Radiación , Neoplasias de Cabeza y Cuello/radioterapia , Aumento de Peso

RESUMEN

OBJECTIVES: Assess the efficacy of biomechanical preparation using a reciprocating system followed by final irrigation protocols, then intracanal medication, on reducing endotoxins and cultivable bacteria of infected teeth in irradiated patients. MATERIALS AND METHODS: Twenty-two infected single-rooted canals in patients submitted to head and neck radiotherapy were prepared by reciprocating motion and 2.5% NaOCl. Patients were randomly divided into two groups of 11 patients before the final irrigation protocol: apical positive pressure (APP) or passive ultrasonic activation (PUA). Both groups were treated in two sessions, using Ca(OH)2 as intracanal medication for 14 days. Root canal content sampling was performed after canal access (S1), after biomechanical preparation plus the irrigation protocol (S2), and after intracanal medication (S3). Chromogenic limulus amoebocyte lysate assay measured endotoxin levels (EU/mL), and bacterial load was determined by culture techniques (CFU/mL). RESULTS: Treatment protocols reduced bacterial counts after S2 in both groups (p = 0.01). S3 differed from S1 (p = 0.01), but not from S2 (p = 0.4). Endotoxin levels were reduced in both groups after S2 (P = 0.03) and were lower in S3 than in S2, with significant differences in the APP group (p = 0.03). CONCLUSIONS: Biomechanical preparation using a reciprocating system and 2.5% NaOCl in irradiated teeth, followed by the irrigation protocol (APP or PUA), demonstrated efficacy in reducing endodontic contaminants. Ca(OH)2 as intracanal medication should be performed in irradiated patients with infected root canals. CLINICAL RELEVANCE: This clinical study demonstrated that endodontic treatment in irradiated patients is efficacious at reducing bacterial load and endotoxin levels.

Asunto(s)

Endotoxinas , Periodontitis Periapical , Humanos , Bacterias , Cavidad Pulpar/microbiología , Periodontitis Periapical/microbiología , Irrigantes del Conducto Radicular/uso terapéutico , Preparación del Conducto Radicular/métodos , Hipoclorito de Sodio/uso terapéutico , Resultado del Tratamiento

RESUMEN

The aim of this study was to evaluate in vitro the effect of calcium hydroxide [Ca(OH)2], 2% chlorhexidine gel (CHX) on macrophages (RAW 264.7) to produce pro-inflammatory cytokines and nitric oxide after pretreatment with lipoteichoic acid (LTA) of Enterococcus faecalis. Forty-eight human single-rooted teeth were instrumented with R25.08 (RECIPROC) and sterilized by gamma irradiation. LTA was inoculated in the root canal of each specimen for 96 hours. Specimens were instrumented with 40.06 and 50.05 (RECIPROC) and medicated with: I) Pyrogen-free saline solution (SS); II) 2% CHX gel; III) Ca(OH)2 + SS; or IV) Ca(OH)2 + CHX for 14 days. Three samples (S) were performed of the root canal of each specimen at: S1) immediately after instrumentation; S2) after Ethylenediaminetetraacetic acid (EDTA); S3) after intracanal medication removal. Subsequent quantification of cytokines (IL-1ß, TNF-α, MIP-1α, IP-10, G-CSF and IL-6) by immunosorbent assay (ELISA) and nitric oxide by the Griess method was carried-out. Data were submitted to a normality test and then analyzed with one-way ANOVA and Tukey test with a significance level of 5% using GraphPad Prism 6. Ca(OH)2 + SS and Ca(OH)2 + CHX presented lower levels of TNF-α, TNF-α, IL-6, G-CSF and nitric oxide. Ca(OH)2 + SS was the most effective in reducing MIP-1α. CHX was effective in reducing IL-6 and G-CSF. Therefore, the combined intracanal medication of calcium hydroxide and chlorhexidine is effective in reducing the cytokines TNF-α, IL-1ß, IL-6, G-CSF and nitric oxide.

Asunto(s)

Óxido Nítrico , Factor de Necrosis Tumoral alfa , Humanos , Hidróxido de Calcio/farmacología , Quimiocina CCL3 , Interleucina-6 , Factor Estimulante de Colonias de Granulocitos

RESUMEN

Abstract The aim of this study was to evaluate in vitro the effect of calcium hydroxide [Ca(OH)2], 2% chlorhexidine gel (CHX) on macrophages (RAW 264.7) to produce pro-inflammatory cytokines and nitric oxide after pretreatment with lipoteichoic acid (LTA) of Enterococcus faecalis. Forty-eight human single-rooted teeth were instrumented with R25.08 (RECIPROC) and sterilized by gamma irradiation. LTA was inoculated in the root canal of each specimen for 96 hours. Specimens were instrumented with 40.06 and 50.05 (RECIPROC) and medicated with: I) Pyrogen-free saline solution (SS); II) 2% CHX gel; III) Ca(OH)2 + SS; or IV) Ca(OH)2 + CHX for 14 days. Three samples (S) were performed of the root canal of each specimen at: S1) immediately after instrumentation; S2) after Ethylenediaminetetraacetic acid (EDTA); S3) after intracanal medication removal. Subsequent quantification of cytokines (IL-1β, TNF-α, MIP-1α, IP-10, G-CSF and IL-6) by immunosorbent assay (ELISA) and nitric oxide by the Griess method was carried-out. Data were submitted to a normality test and then analyzed with one-way ANOVA and Tukey test with a significance level of 5% using GraphPad Prism 6. Ca(OH)2 + SS and Ca(OH)2 + CHX presented lower levels of TNF-α, TNF-α, IL-6, G-CSF and nitric oxide. Ca(OH)2 + SS was the most effective in reducing MIP-1α. CHX was effective in reducing IL-6 and G-CSF. Therefore, the combined intracanal medication of calcium hydroxide and chlorhexidine is effective in reducing the cytokines TNF-α, IL-1β, IL-6, G-CSF and nitric oxide.

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Resumo O objetivo deste estudo foi avaliar in vitro o efeito do hidróxido de cálcio [Ca(OH)2], clorexidina gel a 2% (CHX) em macrófagos (RAW 264.7) na produção de citocinas pró-inflamatórias e óxido nítrico após pré-tratamento com ácido lipoteicóico (LTA) de Enterococcus faecalis. Quarenta e oito dentes humanos uniradiculares foram instrumentados com R25.08 (RECIPROC) e esterilizados por irradiação gama. LTA foi inoculado no canal radicular de cada espécime por 96 horas. Os espécimes foram instrumentados com 40.06 e 50.05 (RECIPROC) e medicados com: I) solução salina apirogênica (SS); II) CHX 2%; III) Ca(OH)2 + SS; ou IV) Ca(OH)2 + CHX durante 14 dias. Três amostras (S) foram realizadas do canal radicular de cada espécime em: S1) imediatamente após a instrumentação; S2) após ácido etilenodiaminotetracético (EDTA); S3) após a retirada da medicação intracanal. Foi realizada a quantificação subsequente de citocinas (IL-1β, TNF-α, MIP-1α, IP-10, G-CSF e IL-6) por imunoensaio (ELISA) e de óxido nítrico pelo método de Griess. Os dados foram submetidos a um teste de normalidade e então analisados com ANOVA one-way e teste de Tukey com nível de significância de 5% usando GraphPad Prism 6. Ca(OH)2 + SS e Ca(OH)2 + CHX apresentaram níveis mais baixos de TNF -α, TNF-α, IL-6, G-CSF e óxido nítrico. Ca(OH)2 + SS foi o mais eficaz na redução de MIP-1α. CHX foi eficaz na redução de IL-6 e G-CSF. Sendo assim a associação de hidróxido de cálcio e clorexidina é eficaz na redução das citocinas TNF-α, IL-1β, IL-6, G-CSF e óxido nítrico.

RESUMEN

This study aimed at evaluating volumetrically gaps and voids of calcium-silicate based materials of different generations and handling properties (BC­Endosequence BC RRM-Fast Set Condensable Putty, MTA­ProRoot MTA, and BIO­Biodentine) in simulated furcal perforations in an ex vivo setup by microcomputed tomography (Micro-CT) analysis. Thirty-six extracted human mandibular molars with sound furcation areas were selected. Standardized perforations were created in the furcation area of the pulp chamber using #4 diamond burs. The specimens were randomly assigned to three groups (BC, MTA and BIO; n = 12). Samples were then scanned (SkyScan 1172; Bruker-microCT, Kontich, Belgium), and three-dimensional (3D) images reconstructed. The relative volume of gaps (VG%) and voids (VV%) present on each material was calculated. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey's HSD test (p < 0.05). Mean VG% for BC, MTA, and BIO groups were, respectively, 0.513%, 1.128%, 1.460%, with BC presenting statistically (p < 0.05) fewer gaps formation than the other groups. Mean VV% were, respectively, 0.018%, 0.037%, and 0.065%. The was no statistical difference regarding VV%. There were no gap-free and void-free samples. BC group had the lowest VG% among the groups with a significant statistical difference (p < 0.05).

RESUMEN

INTRODUCTION: This randomized clinical trial aimed to compare the effectiveness of endodontic retreatment of teeth with posttreatment apical periodontitis (PTAP) performed in 1 visit versus 2 visits on the reduction of cultivable bacteria (colony-forming units [CFUs]), lipopolysaccharides (LPSs), lipoteichoic acid (LTA), and the periapical lesion volume (mm3) after 18 months of follow-up. METHODS: Forty patients diagnosed with PTAP were selected and randomly divided into the following 2 groups: 1-visit retreatment and 2-visit retreatment with the placement of calcium hydroxide medication for 14 days. Cone-beam computed tomographic scans were performed at 2 stages: preoperatively and after 18 months of follow-up. Samples were collected before and after root canal procedures. A chromogenic limulus amebocyte lysate assay test was used to quantify endotoxins (EU/mL). LTA levels were measured using the enzyme-linked immunosorbent assay (pg/mL). Culture techniques were used to determine cultivable bacteria by counting the CFU (CFU/mL). The volume of the periapical lesions at the onset of the trial and at the 18-month posttreatment follow-up was obtained by the ITK-SNAP program (Cognitica, Philadelphia, PA). RESULTS: All samples showed baseline values greater than those collected after the retreatment protocol for all investigated parameters. A higher bacterial load and lower LTA level were found in the 2-visit group after the retreatment protocol (P < .05), with no statistical differences between the groups regarding endotoxin levels and periapical lesion volume (mm³) at the 18-month follow-up analyzed by cone-beam computed tomographic imaging (P > .05). CONCLUSIONS: Endodontic retreatment in 1 or 2 visits exhibited equally favorable periapical healing at 18 months, with no statistically significant differences between groups.

Asunto(s)

Estudios de Seguimiento , Humanos , Retratamiento

RESUMEN

This study aimed at evaluating the volume of gaps and voids, and the total porosity percentage of three calcium-silicate-based materials in mandibular molars apicoectomy by Micro-CT analysis. Thirty-three mesial roots of extracted human mandibular molars were instrumented and obturated. The apical 3mm of each root was resected and prepared. Root-end cavities were filled with EndoSequence BC Putty (BC); ProRoot MTA (MTA) and Biodentine (BIO). Samples were scanned using a Micro-CT scanner and the tridimensional images reconstructed. Percentage of gaps (VG%) and of voids (VV%) were obtained. Porosity percentage (Po%) was also assessed. Data were analysed using Student's t-test (P < 0.05). All materials presented gaps and voids. VG% was 2.006 (BC), 1.882 (MTA) and 1.450 (BIO), and VV% was 0.039 (BC), 0.021 (MTA) and 0.024 (BIO) with no statistical difference. Po% were 56.73 (BC), 51.94 (MTA) and 50.45 (BIO), with BC being statistically (P > 0.05) more porous.

Asunto(s)

Compuestos de Aluminio , Materiales de Obturación del Conducto Radicular , Compuestos de Calcio , Humanos , Óxidos , Obturación del Conducto Radicular , Silicatos , Raíz del Diente , Microtomografía por Rayos X

RESUMEN

This study aimed to evaluate sodium hypochlorite (NaOCl), limewater (LW), and Polymyxin B (PMB) as irrigants over MMP-3, MMP-8 and MMP-9. Thirty-three patients with apical periodontitis of single-rooted teeth were treated according to three-experimental groups (n=11): group-1: 2.5% NaOCl was used as irrigant; group-2: 2.5% NaOCl for the first two files and LW: [0.14% Ca(OH)2] for the last two files; group-3: 2.5% NaOCl for the first two files and PMB for the last two files. The association of Ca(OH)2 and CHX was used as an intracanal medication in all groups. Four root canal samplings (S) were collected: S1) immediately after access cavity; S2) after biomechanical preparation; S3) after EDTA application; and S4) after removal of the intracanal medication. After quantification of MMP-3, MMP-8, and MMP-9, the data were analyzed by Friedman and Kruskal-Wallis tests and completed by Dunn test (5%). Regardless the used irrigant, there was no difference in reducing MMP-3 or MMP-8 (P=0,5273, P=0,7048 respectively). However, in reducing MMP-9 (P=0,0246) the NaOCl group was the most effective followed by NaOCl+LW group and NaOCl+PMB group respectively. The intracanal medication [Ca(OH)2 + CHX] with the NaOCl and NaOCl+LW was effective in reducing MMP-8 (P<0,0001, P=0,0025) and MMP-9 (P=0,0007, P=0,0047) respectively, but not for the group of NaOCl+PMB which was not effective in reducing MMP-8 or MMP-9 (P=0,1718, P=0,1953) respectively. NaOCl and NaOCl+LW were effective in reducing MMP-9 levels, and this effectivity could be improved by the use of the intracanal medication [Ca(OH)2 + CHX] in reducing MMP-8 and MMP-9 levels.

Asunto(s)

Periodontitis Periapical , Hipoclorito de Sodio , Clorhexidina , Cavidad Pulpar , Humanos , Metaloproteinasa 3 de la Matriz , Polimixina B , Irrigantes del Conducto Radicular , Preparación del Conducto Radicular

RESUMEN

This study aimed to compare the effect of conventional irrigation (CI) and passive ultrasonic irrigation (PUI) with 17% EDTA and QMiX on the maximum depth and percentage of sealer penetration into the dentinal tubules by confocal laser scanning microscopy (CLSM) and to describe the cleaning of root canal walls by scanning electron microscopy (SEM). Eighty single-rooted human mandibular premolars were instrumented and randomly assigned to four groups (n = 20): EDTA + CI, QMiX + CI, EDTA + PUI, and QMiX + PUI. Ten samples from each group were examined by SEM (2,000×) and the remaining 40 roots were filled with a single gutta-percha cone and AH Plus sealer mixed with 0.1% rhodamine B for analysis by CLSM (10×). Images were assessed at distances of 2 mm (apical), 5 mm (middle), and 8 mm (coronal) from the apex with the Leica Application Suite V4.10 software. The EDTA + PUI and QMiX + PUI protocols presented higher rates of debris/smear layer removal in the apical and middle thirds. The PUI was superior to CI in the maximum depth of sealer penetration at the middle third. The QMiX + PUI group had a higher percentage of sealer penetration at the apical third. The PUI and QMiX protocol improved debris/smear layer removal and tubular dentin sealer penetration.

RESUMEN

OBJECTIVES: To compare the microbial load and composition and to determine the lipopolysaccharides (LPS) and lipoteichoic acid (LTA) concentrations found in primary apical periodontitis (PAP) and post-treatment apical periodontitis (PTAP), correlating these findings with clinical/tomographic features. MATERIAL AND METHODS: Sixty patients with PAP (31) and PTAP (29) were submitted to clinical and tomographic assessment. Samples were collected from each root canal using paper points for microbiological assessment (culture technique and Checkerboard DNA-DNA hybridization) and determination of LPS and LTA levels (limulus amebocyte lysate and enzyme-linked immunosorbent assays, respectively). Data were correlated with clinical/tomographic findings and statistically analyzed using the Mann-Whitney and Pearson correlation tests (α = 5%). RESULTS: A higher number of cultivable bacteria and LPS were found in PAP (p < 0.05). The median number of species per root canal found in PAP and PTAP was 9 and 22, respectively (p < 0.05). LPS was positively correlated with a larger periapical lesion volume (p < .05). LTA levels were similar in both infections and had no correlation with signs and symptoms. In PAP, gram-positive bacteria were correlated with spontaneous pain (p < .05) and exudate (p < .05). Tenderness to percussion and pain on palpation were correlated to the presence of both gram-positive and negative bacteria. In PTAP, a positive correlation was observed between both gram-positive and gram-negative bacteria with exudate and periapical lesion volume (p < .05). CONCLUSIONS: PAP had higher contents of microbial load and LPS compared with PTAP. However, PTAP presented a more diverse microbiota compared with PAP. Higher content of LPS was positively correlated with larger periapical bone destruction, whereas signs and symptoms with specific microorganisms. CLINICAL RELEVANCE: It was verified that PAP and PTAP are polymicrobial infections with predominance of gram-negative bacteria and a more diverse bacterial population found in PTAP. A wide interaction of specific microbial species resulted in different clinical features in both infections.

Asunto(s)

Lipopolisacáridos , Periodontitis Periapical , Antibacterianos , Cavidad Pulpar , Bacterias Gramnegativas , Bacterias Grampositivas , Humanos , Periodontitis Periapical/complicaciones , Periodontitis Periapical/metabolismo , Periodontitis Periapical/microbiología , Ácidos Teicoicos

RESUMEN

BACKGROUND/AIM: In addition to their anti-inflammatory and anti-osteoclastogenesis properties, adrenergic blockers may also have promising anti-resorptive effects that can prevent root resorption when teeth are replanted because of avulsion. The aim of this study was to investigate the effects of phentolamine (Ph) and propranolol (Pr) in gels on the repair process of late replanted rat incisors. A further aim was to evaluate the biocompatibility of both drugs to human periodontal ligament fibroblasts (HPDLFs). MATERIALS AND METHODS: Forty-eight maxillary right incisors were extracted from male Wistar rats, stored in paper napkins for 60 minutes, and randomly allocated to one of eight groups (n = 6). The root canal, root surface, and alveolus were treated with 0.75 µg/mL Ph gel (Ph0.75), 10 µg/mL Ph gel (Ph10), 100 µg/mL Ph gel (Ph100), 2.5 µg/mL Pr gel (Pr2.5), 10 µg/mL Pr gel (Pr10), 100 µg/mL Pr gel (Pr100), or sodium carboxymethylcellulose gel (CMC) before replantation. In the control group (CH), only the root canal was treated with calcium hydroxide paste. Thirty days following surgery, the animals were euthanized, and the right hemimaxilla was removed to perform micro-CT and histomorphometric analysis to determine osteoclastic activity. Ethanolic solutions of Ph10 and Pr10 were selected based on the in vivo study, and the viability of HPDLFs stimulated with lipopolysaccharide was determined by MTT assays. RESULTS: The micro-CT and histomorphometric analysis revealed no significant differences among the treatments (P > .05). The presence of active osteoclasts was significantly decreased in the Ph10 and Pr10 groups (P < .05). Ph10 and Pr10 produced statistically similar cell survival rates compared to the control group (P > .05). CONCLUSIONS: Ph10 and Pr10 significantly decreased osteoclastogenesis in delayed replanted rat teeth and were not cytotoxic toward HPDLFs.

Asunto(s)

Incisivo , Resorción Radicular/prevención & control , Antagonistas Adrenérgicos , Animales , Antiinflamatorios , Masculino , Ratas , Ratas Wistar , Reimplante Dental , Raíz del Diente

RESUMEN

OBJECTIVE: This clinical study sought to evaluate the effectiveness of passive ultrasonic activation (PUA) in eliminating microorganisms in primary endodontic infection (PEI) after instrumentation of root canals using microbiological culture and checkerboard DNA-DNA hybridization. METHODOLOGY: Twenty root canals with PEI and apical periodontitis were selected. The root canals were instrumented and then randomly divided into 2 groups, according to the irrigation method: PUA and conventional needle irrigation (CNI). Microbiological samples were collected before instrumentation (S1), after instrumentation (S2) and after irrigation with 17% EDTA (S3). The samples were subjected to anaerobic culture technique and checkerboard DNA-DNA hybridization analysis. RESULTS: A statistically significant difference was found between CNI (23.56%) and PUA (98.37%) regarding the median percentage values for culturable bacteria reduction (p<0.05). In the initial samples, the most frequently detected species was S. constellatus (50%), and after root canal treatment was E. faecalis (50%). CONCLUSION: Both treatments significantly decreased the number of bacterial species compared with the initial sample. However, no statistical difference in the total microbial load between PUA and CNI groups was detected. The number of cultivable anaerobic bacteria reduced significantly using PUA, and the bacterial composition and number of bacterial species after using either CNI or PUA was similar.

Asunto(s)

Cavidad Pulpar/microbiología , Periodontitis Periapical/terapia , Tratamiento del Conducto Radicular/instrumentación , Terapia por Ultrasonido/instrumentación , Adolescente , Adulto , Análisis de Varianza , Bacterias/aislamiento & purificación , Carga Bacteriana , Recuento de Colonia Microbiana , Tomografía Computarizada de Haz Cónico , Sondas de ADN , Femenino , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Irrigantes del Conducto Radicular/uso terapéutico , Tratamiento del Conducto Radicular/métodos , Hipoclorito de Sodio/uso terapéutico , Irrigación Terapéutica/instrumentación , Irrigación Terapéutica/métodos , Resultado del Tratamiento , Terapia por Ultrasonido/métodos , Adulto Joven

RESUMEN

OBJECTIVE: To investigate the influence of chronic stress and adrenergic blockade in a rat model of apical periodontitis. METHODS: Thirty-two Wistar rats were submitted to an animal model of periapical lesion and randomly divided into 4 groups (n = 8): no stress (NS); stress + saline solution (SS); stress + ß-adrenergic blocker (Sß); stress + α-adrenergic blocker (Sα). The SS, Sß and Sα groups were submitted to an animal model of chronic stress for 28 days and received daily injections of saline solution, propranolol (ß adrenergic blocker) and phentolamine (α adrenergic blocker), respectively. After 28 days the animals were euthanized and the following analyses were carried out: a) serum corticosterone levels through Radioimmunoassay; b) measurement of serum levels of IL-1B, IL-6, IL-10 and IL-17 by enzyme-linked immunosorbent assay (ELISA); c) volume of periapical bone resorption by micro-computed tomography; d) histomorphometric analysis by staining with hematoxylin and eosin; e) expression of ß-AR, α-AR, receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) by immunohistochemistry; f) tartrate-resistant acid phosphatase (TRAP) staining; g) ex-vivo cytokine release followed by the stimulation with LPS in superfusion system, by ELISA. RESULTS: SS group displayed significantly higher corticosterone levels than NS group (non-stressed). Higher IL-1ß serum level was observed in the NS group (p < .05); compared to all stressed groups. Other cytokines were present in similar amounts in the serum of all groups. All groups presented similar periapical lesions. All groups presented moderate inflammatory infiltrate, without statistically significant differences between them. No differences were observed regarding ß-AR, α-AR, Rank-L and OPG expression. The number of TRAP-positive cells was significantly decreased in the groups that received daily injections of adrenergic blockers. The IL-1ß release followed LPS stimulation was significantly suppressed when the superfusion media contained propranolol (p < .05). Perfusion containing phentolamine induced a greater release of IL-10. TGF-ß was significantly suppressed by phentolamine perfusion in the NS group (p < .05). CONCLUSIONS: Chronic stress can significantly change the inflammatory cytokines release. Rank-L/OPG system and periapical lesion volume were not affected following the current method applied. The administration of adrenergic blockers was not able to modulate the inflammatory response but presented effectivity in reducing the number of osteoclasts in the periapical region.

Asunto(s)

Resorción Ósea , Inflamación , Periodontitis Periapical , Receptores Adrenérgicos , Estrés Fisiológico , Adrenérgicos , Animales , Osteoprotegerina , Estrés Oxidativo , Periodontitis Periapical/fisiopatología , Ligando RANK , Ratas , Ratas Wistar , Receptores Adrenérgicos/fisiología , Microtomografía por Rayos X

RESUMEN

Abstract Objective: This clinical study sought to evaluate the effectiveness of passive ultrasonic activation (PUA) in eliminating microorganisms in primary endodontic infection (PEI) after instrumentation of root canals using microbiological culture and checkerboard DNA-DNA hybridization. Methodology: Twenty root canals with PEI and apical periodontitis were selected. The root canals were instrumented and then randomly divided into 2 groups, according to the irrigation method: PUA and conventional needle irrigation (CNI). Microbiological samples were collected before instrumentation (S1), after instrumentation (S2) and after irrigation with 17% EDTA (S3). The samples were subjected to anaerobic culture technique and checkerboard DNA-DNA hybridization analysis. Results: A statistically significant difference was found between CNI (23.56%) and PUA (98.37%) regarding the median percentage values for culturable bacteria reduction (p<0.05). In the initial samples, the most frequently detected species was S. constellatus (50%), and after root canal treatment was E. faecalis (50%). Conclusion: Both treatments significantly decreased the number of bacterial species compared with the initial sample. However, no statistical difference in the total microbial load between PUA and CNI groups was detected. The number of cultivable anaerobic bacteria reduced significantly using PUA, and the bacterial composition and number of bacterial species after using either CNI or PUA was similar.

Asunto(s)

Humanos , Masculino , Femenino , Adolescente , Adulto , Persona de Mediana Edad , Periodontitis Periapical/terapia , Tratamiento del Conducto Radicular/instrumentación , Terapia por Ultrasonido/instrumentación , Cavidad Pulpar/microbiología , Irrigantes del Conducto Radicular/uso terapéutico , Tratamiento del Conducto Radicular/métodos , Hipoclorito de Sodio/uso terapéutico , Bacterias/aislamiento & purificación , Terapia por Ultrasonido/métodos , Recuento de Colonia Microbiana , Sondas de ADN , Modelos Lineales , Análisis de Varianza , Resultado del Tratamiento , Tomografía Computarizada de Haz Cónico , Carga Bacteriana , Irrigación Terapéutica/instrumentación , Irrigación Terapéutica/métodos

RESUMEN

BACKGROUND: Endocrown restorations as a conservative approach to restore endodontically treated teeth still need in vitro investigation under fatigue and made in different materials. This study evaluated the effect of restorative material and restoration thickness on the maximum fracture load of endocrowns subjected to cyclic loading. MATERIAL AND METHODS: Sixty (60) third molar teeth received an endocrown preparation with three different heights of remaining dental tissue (1.5, 3.0 or 4.5 mm). A leucite-based ceramic (LEU) and a lithium disilicate (LD) based ceramic were selected to manufacture the CAD/CAM endocrown restorations, totaling 6 groups (n=10). The specimens were subjected to fatigue loading (200N, 2 x 106 cycles, water) and then to the single load to failure test (1 mm/min crosshead speed). Data were analyzed by using two-way ANOVA and Tukey tests (p< 0.05). RESULTS: All endocrowns survived the fatigue test. The thickness did not influence the restoration's fracture load (p=0.548) instead the restorative material (p=0.003). LD showed higher mean values (1714.43 N)A than LEU (1313.47 N)B. CONCLUSIONS: Endocrowns manufactured with CAD/CAM lithium disilicate blocks showed superior fracture load than the leucite-based blocks after mechanical fatigue. Nevertheless, both materials presented acceptable survival and fracture load as long as the material's minimum thickness and the enamel adhesion are respected. Key words:Endocrown, CAD/CAM, Endodontically treated teeth, Failure load, Minimal intervention dentistry.

RESUMEN

This study evaluated the influence of zirconia surface finishes on the wear of an enamel analogue. 40 zirconia discs were divided into four groups: control (without finish); glazed; polished; polished and glazed. All samples were subjected to wear against steatite antagonists. The specimens underwent roughness, topographic, scanning electron microscopy (SEM) and wettability analyses. Quantitative wear measurements were performed on both steatites and discs. To measure wear of steatites the weight before and after the test and the diameter after the test were used. Profilometer measurements were performed to determine the wear on discs. Roughness, volumetric wear and mass loss were analyzed using the Kruskal-Wallis and Dunn tests (5%), while contact angle values were analyzed with One-way ANOVA and Tukey tests (5%). The polished group had the lowest roughness means, being statistically different from the other groups (p-value=0.0001). The glazed group presented the lowest steatite volumetric wear (p-value=0.0001), but not statistically different from the polished and glazed group, whereas these groups presented the highest zirconia volumetric wear, with statistically different (p-value=0.0002) compared to the others. SEM showed irregularities on the control groups surface, grooves on the polished group, and a homogeneous surface for the glazed group with a few pores. All groups presented contact angles lower than 90 degrees, characterizing hydrophilic surfaces. It can be concluded that just glazed zirconia caused less wear on the antagonist when compared to no finish and polished zirconia.

Asunto(s)

Porcelana Dental , Circonio , Pulido Dental , Ensayo de Materiales , Propiedades de Superficie

RESUMEN

Abstract This study evaluated the influence of zirconia surface finishes on the wear of an enamel analogue. 40 zirconia discs were divided into four groups: control (without finish); glazed; polished; polished and glazed. All samples were subjected to wear against steatite antagonists. The specimens underwent roughness, topographic, scanning electron microscopy (SEM) and wettability analyses. Quantitative wear measurements were performed on both steatites and discs. To measure wear of steatites the weight before and after the test and the diameter after the test were used. Profilometer measurements were performed to determine the wear on discs. Roughness, volumetric wear and mass loss were analyzed using the Kruskal-Wallis and Dunn tests (5%), while contact angle values were analyzed with One-way ANOVA and Tukey tests (5%). The polished group had the lowest roughness means, being statistically different from the other groups (p-value=0.0001). The glazed group presented the lowest steatite volumetric wear (p-value=0.0001), but not statistically different from the polished and glazed group, whereas these groups presented the highest zirconia volumetric wear, with statistically different (p-value=0.0002) compared to the others. SEM showed irregularities on the control groups surface, grooves on the polished group, and a homogeneous surface for the glazed group with a few pores. All groups presented contact angles lower than 90 degrees, characterizing hydrophilic surfaces. It can be concluded that just glazed zirconia caused less wear on the antagonist when compared to no finish and polished zirconia.

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Resumo Este estudo avaliou a influência dos acabamentos superficiais da zircônia no desgaste de um análogo de esmalte. 40 discos de zircônia foram divididos em quatro grupos: controle (sem acabamento); glazeado; polido; polido e glazeado. Todas as amostras foram submetidas ao desgaste contra antagonistas de esteatita. Os espécimes foram submetidos à análise de rugosidade, topografia, microscopia eletrônica de varredura (MEV) e análise de molhabilidade. Medidas quantitativas de desgaste foram realizadas nos antagonistas e nos discos de zircônia. Para medir o desgaste das esteatitas, foi mensurado o peso antes e depois do desgaste e o diâmetro após o teste. A análise de perfilometria mensurou o desgaste dos discos. Rugosidade, desgaste volumétrico e perda de massa foram analisados pelos testes de Kruskal-Wallis e Dunn (5%), enquanto os valores de ângulo de contato foram analisados com os testes One-way ANOVA e Tukey (5%). O grupo polido apresentou as menores médias de rugosidade, sendo estatisticamente diferente dos demais grupos (p-valor=0,0001). O grupo glazeado apresentou o menor desgaste volumétrico do antagonista (p-valor=0,0001), mas não foi estatisticamente diferente do grupo polido e glazeado, enquanto que esses grupos apresentaram o maior desgaste volumétrico da zircônia, com diferença estatisticamente diferente (p-valor=0,0002) em comparação com os outros. MEV mostrou irregularidades na superfície do grupo controle, sulcos no grupo polido e uma superfície homogênea para o grupo glazeado, com poucos poros. Todos os grupos apresentaram ângulos de contato menores que 90 graus, caracterizando superfícies hidrofílicas. Dentro das limitações deste estudo in vitro, é possível concluir que zircônia glazeada causou menos desgaste ao antagonista quando comparada a zircônia sem tratamento ou polida. Além disso, não foi encontrada diferença no desgaste do antagonista para os grupos de zirconia polida e controle.

Asunto(s)

Circonio , Porcelana Dental , Propiedades de Superficie , Ensayo de Materiales , Pulido Dental

RESUMEN

AIMS: The aim of this study was to evaluate the diffusion of hydroxyl ion to the external root surface using different irrigating solutions and intracanal medication with calcium hydroxide. MATERIALS AND METHODS: Sixty bovine tooth roots were randomly divided into six experimental groups (n = 10), according to the irrigating substance used during biomechanical preparation: 12% glycolic propolis extract (PROP); 20% glycolic ginger extract (GENG); 2% sodium hypochlorite with surfactant (NaOClS); 2% chlorhexidine gel (CLX); 2.5% sodium hypochlorite (NaOCl); and physiological saline solution. After filling the root canals with calcium hydroxide paste, pH measurements were taken directly at the external cavities over time intervals of up to 30 days. STATISTICAL ANALYSIS USED: Data were submitted to two-way ANOVA and Tukey's test (P < 0.05). RESULTS: The pH of the external root surface was increased when the surfactant associated with NaOCl was used. However, the pH values were very close for the different groups. Hydroxyl ion diffusion up to the external root surface did not exceed the pH value of 8.5, and in the hollow passage of the canal, the pH was higher than 12. CONCLUSIONS: Hydroxyl ion diffusion of calcium hydroxide paste through the dentinal tubules up to the external root surface allows minimal alkalinization of this surface, and it is greater when using NaOCl with surfactant during biomechanical preparation.

Asunto(s)

Hidróxido de Calcio , Irrigantes del Conducto Radicular , Animales , Bovinos , Hidróxidos , Hipoclorito de Sodio