RESUMO
INTRODUCTION: Conventional endodontic treatment includes instrumentation of the canals in most cases to size #25/.06 or larger, which changes the original canal wall anatomy. In recent years, energy-driven equipment, such as photon-induced photoacoustic streaming (Fotona LLC, Dallas, TX) and a multisonic GentleWave system (Sonendo Inc, Laguna Hills, CA), have been introduced to facilitate cleaning of minimally instrumented canals or even uninstrumented canals. The purpose of this study was to examine root canal wall anatomy in premolar teeth cleaned by a noninstrumentation method after #10 K-file patency examination. METHODS: Twenty-four freshly extracted human premolars were accessed, and patency was established by a #10 K-file. Seventeen teeth were treated by the GentleWave system using 3% sodium hypochlorite, and 7 untreated teeth served as negative controls. The dentin surface in the coronal, middle, and apical thirds of the root canal was examined by scanning electron microscopy after tooth splitting. The canal wall structures were assessed using a predefined scale of 4 parameters: calcospherites, surface irregularities, dentinal tubule openings, and tissue debris. RESULTS: A clean surface of mineralized dentin was exposed with no organic tissue remnants or debris left in the root canal system, including the isthmus areas between the 2 canals. The uninstrumented root canals showed an irregular dentin structure in many areas, including previously unreported fingerlike projections. The isthmus areas had no or only a few dentinal tubule openings. The dentin structures were well preserved in the test group, whereas in the untreated control teeth tissue debris covered most of the dentin surface. CONCLUSIONS: Root canal wall dentin in premolars cleaned with a noninstrumentation method showed a wide structural variety, especially in the middle and apical region. No organic tissue remnants or dentin debris were detected.
Assuntos
Dente Pré-Molar/ultraestrutura , Cavidade Pulpar/ultraestrutura , Dentina/ultraestrutura , Humanos , Microscopia Eletrônica de Varredura , Preparo de Canal Radicular , Ápice Dentário/ultraestruturaRESUMO
INTRODUCTION: The aim of this study was to evaluate, under scanning electronic microscopy, the morphological aspect of apical foramen after root canal instrumentation with rotary and reciprocating kinematics at 2 different working length determinations. METHODOLOGY: Sixty mesiobuccal roots of mandibular and maxillary molars presenting with curvature ranging from 30 to 65° were used in this study. The roots were initially scanned with a scanning electronic microscope under ×50 magnification. Roots were divided into 2 different groups (n = 30): group 1 instrumented with rotary kinematics, and group 2 instrumented with reciprocating kinematics. Both groups were instrumented at 2 different working lengths: at the apex and 1 mm beyond the apex. The roots were scanned after the instrumentation at the apex and again after further instrumentation 1 mm beyond the apex. The photomicrographs obtained were assigned to 3 independent evaluators for foraminal deformation assessment through comparison with baseline images. Evaluators were masked with regard to the kinematics and working length used. The Pearson correlation test and Kruskal-Wallis test (method of Dunn) were used for statistical analysis (P < .05). RESULTS: The Pearson Correlation test showed good agreement among evaluators. Foraminal deformation was observed in instrumentation at the apex and 1 mm beyond the apex with both kinematics (P < .05). CONCLUSIONS: Within the limitations of this study, it can be concluded that root canal instrumentation at the apex or 1 mm beyond the apex promoted deformation of the major foramen, regardless of the kinematics.
Assuntos
Preparo de Canal Radicular/métodos , Ápice Dentário/ultraestrutura , Fenômenos Biomecânicos , Humanos , Microscopia Eletrônica de Varredura , Preparo de Canal Radicular/instrumentaçãoRESUMO
The purpose of the study presented here was to compare the influence of root canal taper on the efficacy of irrigants and chelating agents in smear layer removal. Eighty mesial roots of molar teeth were selected and prepared with rotary instruments. In group A, file 30/0.02 and in group B, file 30/0.4 were placed at working length and the smear layer was removed. In groups C and D, root canal preparation was the same as in groups A and B, respectively, except that the smear layer was not removed. The amount of the smear layer was quantified using a scanning electron microscope. Greater smear layer was detected in the apical portion of each group, whereas no significant difference was detected between groups in other portions. No statistical difference was found between canals with different tapers.
Assuntos
Quelantes/uso terapêutico , Irrigantes do Canal Radicular/uso terapêutico , Preparo de Canal Radicular/métodos , Camada de Esfregaço/tratamento farmacológico , Cavidade Pulpar/efeitos dos fármacos , Cavidade Pulpar/ultraestrutura , Ácido Edético/uso terapêutico , Desenho de Equipamento , Humanos , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Distribuição Aleatória , Preparo de Canal Radicular/instrumentação , Camada de Esfregaço/patologia , Hipoclorito de Sódio/uso terapêutico , Propriedades de Superfície , Ápice Dentário/efeitos dos fármacos , Ápice Dentário/ultraestruturaRESUMO
INTRODUCTION: The aim of this study was to determine the efficiency of 4 irrigation systems in eliminating bacteria in root canals, particularly in dentinal tubules. METHODS: Roots of human teeth were prepared to 25/04, autoclaved, and inoculated with Enterococcus faecalis for 3 weeks. Canals were then disinfected by (1) standard needle irrigation, (2) sonically agitating with EndoActivator, (3) XP Endo finisher, or (4) erbium:yttrium aluminum garnet laser (PIPS) (15 roots/group). The bacterial reduction in the canal was determined by MTT assays. For measuring live versus dead bacteria in the dentinal tubules (4 teeth/group), teeth were split open and stained with LIVE/DEAD BackLight. Coronal, middle, and apical thirds of the canal dentin were scanned by using a confocal laser scanning microscope (CLSM) to determine the ratio of dead/total bacteria in the dentinal tubules at various depths. RESULTS: All 4 irrigation protocols significantly eliminated bacteria in the canal, ranging from 89.6% to 98.2% reduction (P < .001). XP Endo had the greatest bacterial reduction compared with other 3 techniques (P < .05). CLSM analysis showed that XP Endo had the highest level of dead bacteria in the coronal, middle, and apical segments at 50-µm depth. On the other hand, PIPS had the greatest bacterial killing efficiency at the 150-µm depth in all 3 root segments. CONCLUSIONS: XP Endo appears to be more efficient than other 3 techniques in disinfecting the main canal space and up to 50 µm deep into the dentinal tubules. PIPS appears to be most effective in killing the bacteria deep in the dentinal tubules.
Assuntos
Bactérias/efeitos dos fármacos , Dentina/efeitos dos fármacos , Dentina/diagnóstico por imagem , Dentina/microbiologia , Microscopia Confocal/métodos , Irrigantes do Canal Radicular/farmacologia , Bactérias/crescimento & desenvolvimento , Carga Bacteriana , Técnicas Bacteriológicas , Dente Pré-Molar/diagnóstico por imagem , Dente Pré-Molar/efeitos dos fármacos , Dente Pré-Molar/microbiologia , Cavidade Pulpar/microbiologia , Cavidade Pulpar/ultraestrutura , Dentina/ultraestrutura , Desinfecção/métodos , Ácido Edético/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/crescimento & desenvolvimento , Humanos , Lasers de Estado Sólido/uso terapêutico , Mandíbula , Teste de Materiais , Viabilidade Microbiana/efeitos dos fármacos , Dente Molar/diagnóstico por imagem , Dente Molar/efeitos dos fármacos , Dente Molar/microbiologia , Irrigantes do Canal Radicular/administração & dosagem , Preparo de Canal Radicular/métodos , Hipoclorito de Sódio/administração & dosagem , Hipoclorito de Sódio/farmacologia , Sonicação/métodos , Ápice Dentário/diagnóstico por imagem , Ápice Dentário/efeitos dos fármacos , Ápice Dentário/microbiologia , Ápice Dentário/ultraestruturaRESUMO
INTRODUCTION: This study evaluated the integrity of calcium silicate sealer-based fillings made with hygro-expandable cones (HEC) that are commercially known as CPoint or Smartpoint. METHODS: Fourteen human canines were prepared according to a standardized, conventional endodontic treatment protocol and filled with the HEC/calcium silicate sealer. Three-dimensional imaging was performed with laboratory micro-computed tomography (µCT) at its highest resolution and was compared with synchrotron phase contrast-enhanced µCT (PCE-CT) scans of the treatment extending 1-7 mm from the apex. Conventional destructive optical microscopy validated observations by comparison with virtual slices in the tomographic data. RESULTS: Conventional laboratory µCT at 10-µm resolution did not reveal the existing voids and defects within the root canal fillings. PCE-CT revealed elongated interfacial delamination localized mainly at the HEC-sealer interface forming extended through-and-through gaps along the root canal filling. CONCLUSIONS: Endodontic studies that use conventional laboratory µCT may underestimate thin defects and delamination within root canal fillings made with HEC because of limited resolution and contrast of laboratory-based broad-spectrum low intensity x-ray sources. These limitations favor use of high-brilliance, monochromatic synchrotron-based PCE-CT to reveal the important micrometer details within large (millimeter sized) samples. PCE-CT revealed the existence of a range of significant structural defects in recently placed HEC fillings, confirmed by optical microscopy after physical sectioning. Substantial delamination spanning 20%-40% of the circumferential interface as well as other structural defects were identified within root canal fillings made of HEC and calcium silicate sealer.
Assuntos
Materiais Restauradores do Canal Radicular/química , Síncrotrons/instrumentação , Água/química , Microtomografia por Raio-X/instrumentação , Microtomografia por Raio-X/métodos , Anatomia Transversal , Compostos de Cálcio , Dente Canino/diagnóstico por imagem , Dentina/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional/instrumentação , Imageamento Tridimensional/métodos , Irrigantes do Canal Radicular , Obturação do Canal Radicular/métodos , Preparo de Canal Radicular/instrumentação , Silicatos/química , Ápice Dentário/diagnóstico por imagem , Ápice Dentário/ultraestruturaRESUMO
AIM: The present SEM study was undertaken to evaluate the effect of root canal instrumentation using both manual and rotary files in the root canals of primary anterior teeth. STUDY DESIGN: Thirty freshly extracted primary maxillary incisors were divided into 3 groups of 10 teeth each. In Group I, root canals were instrumented with rotary NiTi files; in Group II, the root canals were instrumented using manual NiTi K files and; in Group III, manual instrumentation was done with stainless steel K files. Longitudinal sections were prepared and processed for observation under SEM at the coronal, middle and apical thirds. Scoring of smear layer was done according to Hulsmann and the data obtained was subjected to statistical analysis. RESULTS: Rotary files cleaned the coronal and middle thirds of root canals more effectively. Statistically there was no significant difference between the groups. Lowest score of 2.6 in the apical third of root canals was seen with hand NiTi files. CONCLUSION: Rotary instrumentation was as effective as manual instrumentation in removal of smear layer in the root canals of primary anterior teeth.
Assuntos
Cavidade Pulpar/ultraestrutura , Preparo de Canal Radicular/instrumentação , Camada de Esfregaço/ultraestrutura , Dente Decíduo/ultraestrutura , Ligas Dentárias/química , Desenho de Equipamento , Humanos , Incisivo/ultraestrutura , Teste de Materiais , Microscopia Eletrônica de Varredura , Níquel/química , Distribuição Aleatória , Rotação , Aço Inoxidável/química , Titânio/química , Ápice Dentário/ultraestruturaRESUMO
INTRODUCTION: The objective of this ex vivo study was to compare the efficacy of passive ultrasonic irrigation (PUI) versus a new activation system using reciprocating motion (EasyClean [EC]; Easy Equipamentos Odontológicos, Belo Horizonte, Brazil) to remove debris from the root canal walls at 6 predetermined apical levels using environmental scanning electron microscopy. METHODS: Mesiobuccal root canals of 10 mandibular molars were prepared with a 30/.05 final instrument. The specimens were embedded in flasks containing heavy body silicone, cleaved longitudinally, and 6 round indentations were made into the apical region of the buccal half at 1-mm intervals. The same specimens were used to prepare a blank control group (no debris), a negative control group (completely covered by debris), and 2 experimental groups: PUI and irrigation with reciprocating activation. Standardized images of the indentations were obtained under environmental scanning electron microscopy and assessed by 2 examiners. The amount of debris was then classified using a 4-category scoring system. The kappa test was applied to determine interexaminer agreement, whereas the Kruskal-Wallis, Dunn, and Friedman tests were used to compare scores. RESULTS: The EC group had results statistically similar to those of the blank control group for all 6 root levels examined. The PUI group had results statistically similar to those of the negative control group for the 3 most apical levels and similar to those of the blank control group for the 3 most cervical levels. CONCLUSIONS: Activating the irrigant with a reciprocating system (EC) promoted more effective debris removal from the more apical regions of the root canal when compared with PUI.
Assuntos
Microscopia Eletrônica de Varredura/métodos , Irrigantes do Canal Radicular/química , Preparo de Canal Radicular/métodos , Irrigação Terapêutica/métodos , Terapia por Ultrassom/métodos , Desbridamento/métodos , Cavidade Pulpar/ultraestrutura , Dentina/ultraestrutura , Humanos , Preparo de Canal Radicular/instrumentação , Tratamento do Canal Radicular/instrumentação , Tratamento do Canal Radicular/métodos , Hipoclorito de Sódio/química , Ápice Dentário/ultraestrutura , Terapia por Ultrassom/instrumentaçãoRESUMO
This study was designed to examine the morphological features of the resected root apices obtained from endodontic microsurgery using a scanning electron microscope (SEM) as well as their anatomical effect on the clinical outcome of the surgical treatment. One-hundred-six resected root apices from 91 patients/surgeries were obtained by endodontic microsurgery, and fixed immediately for storage. The resected apices were prepared for SEM to examine their morphological features, such as the number and size of the apical foramina. The patients were periodically checked up at least 1 year and the clinical outcome of the microsurgery was judged as a success or failure according to the Molven's criteria. The SEM findings and the clinical outcome of apical surgery were evaluated to see any potential correlation between them. The SEM examination revealed that 60.4% of specimens had more than two portals of exit on the resected root apices and the size of the major foramen was at least 386 micrometer and 334 micrometer from maxillary and mandibular molar, respectively. With a recall rate of 72.9%, 91.9% of the surgical cases were decided to have successful outcomes. Based on this SEM study, a relatively high frequency of multiple portals of exit was existed and the sizes of major foramina were bigger than that were reported in previous reports. The clinical outcomes of endodontic microsurgery were not correlated with the anatomical features of resected apical root apices. SCANNING 38:455-461, 2016. © 2016 Wiley Periodicals, Inc.
Assuntos
Endodontia , Microscopia Eletrônica de Varredura/métodos , Microcirurgia , Ápice Dentário/ultraestrutura , Raiz Dentária/ultraestrutura , Humanos , Ápice Dentário/cirurgiaRESUMO
PURPOSE: Achieving optimal moisture inside the root canal is a challenge during bonding of fiberglass posts. This study evaluated the effect of different moisture patterns on the push-out bond strength (PBS) and nanoleakage (NL) of fiber posts bonded to the root canal of two simplified etch-and-rinse adhesives. MATERIALS AND METHODS: The roots of 72 human premolars were endodontically prepared and divided into 6 groups according to the combination of the main factors: adhesive (Ambar and Adper Single Bond 2) and moisture (dry, wet, and overwet). The posts were cemented and after 1 week, the roots were cross sectioned into 6 disks. Two disks each were obtained from the cervical, middle, and apical thirds, and the PBS test was carried out (0.5 mm/min; n = 8). The NL was evaluated by scanning electron microscopy after the immersion of specimens in 50% silver nitrate (n = 4). The failure pattern was examined on all debonded specimens. Data were analyzed by three-way repeated measures ANOVA and Tukey's test (5%). RESULTS: For both adhesives, higher PBS values and lower NL were observed in the wet groups, and lower PBS and higher NL in the dry group. In general, the overwet condition showed intermediate results. CONCLUSIONS: The root dentin walls should be left slightly moist before performing fiber post cementation procedures.
Assuntos
Cimentação/métodos , Materiais Dentários/química , Cavidade Pulpar/ultraestrutura , Dentina/ultraestrutura , Vidro/química , Técnica para Retentor Intrarradicular/instrumentação , Colagem Dentária , Cimentos Dentários/química , Corrosão Dentária/métodos , Infiltração Dentária/classificação , Adesivos Dentinários/química , Dessecação , Humanos , Teste de Materiais , Metacrilatos/química , Microscopia Eletrônica de Varredura , Distribuição Aleatória , Coloração pela Prata , Estresse Mecânico , Propriedades de Superfície , Fatores de Tempo , Ápice Dentário/ultraestrutura , Dente não Vital/patologia , Água/químicaRESUMO
AIM: The aim of this study was to evaluate the effect of chlorhexidine and ethanol application on the push-out bond strength and bond durability of fiber posts cemented with an etch-and-rinse adhesive system/resin cement to intraradicular dentin. MATERIALS AND METHODS: Fifty-four bovine roots were shaped for the cementation of a fiberglass post and received the application of 37% phosphoric acid. They were then randomly divided into three groups, according to the type of dentin treatment (n = 18) performed: no treatment (control group), 100% ethanol, or 2% chlorhexidine. Next, the adhesive system (Adper Scotch Bond Multipurpose Plus, 3M ESPE) was applied to the dentin, according to the manufacturer's instructions. Glass fiber posts were cemented with dual resin cement (Rely X ARC, 3M ESPE). After 48 hours, the specimens were serially sectioned for push-out test analysis, providing two slices from each root third (cervical, medium and apical), one of which was tested immediately and the other stored in distilled water for 180 days. The data were analyzed with three-way analysis of variance (ANOVA) for repeated measures and Tukey's test at a 5% significance level. RESULTS: Intraradicular treatment with chlorhexidine yielded the highest bond strength means, followed by ethanol treatment. The control group presented the lowest bond strength means. Water storage exerted no effect on bond strength values. CONCLUSION: Both chlorhexidine and ethanol improved push-out bond strength to intraradicular dentin, with the former providing the best results, regardless of the storage time. CLINICAL SIGNIFICANCE: The application of 2% chlorhexidine or 100% ethanol may be an important step that can be taken to enhance bond strength of fiber posts to intraradicular dentin, when dual resin cements are used.
Assuntos
Clorexidina/química , Colagem Dentária , Cavidade Pulpar/ultraestrutura , Dentina/ultraestrutura , Etanol/química , Técnica para Retentor Intrarradicular/instrumentação , Irrigantes do Canal Radicular/química , Condicionamento Ácido do Dente/métodos , Animais , Bis-Fenol A-Glicidil Metacrilato/química , Bovinos , Cimentação/métodos , Materiais Dentários/química , Adesivos Dentinários/química , Vidro/química , Teste de Materiais , Ácidos Fosfóricos/química , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Distribuição Aleatória , Cimentos de Resina/química , Estresse Mecânico , Fatores de Tempo , Ápice Dentário/ultraestrutura , Água/químicaRESUMO
PURPOSE: To evaluate the effect of different radiant exposure values delivered to two simplified etch-and-rinse adhesive systems on push-out bond strength (PBS) of fiber posts to root canal, as well as nanoleakage (NL) and in situ degree of conversion (DC) within the hybrid layer. MATERIALS AND METHODS: The roots of human premolars were endodontically prepared and divided into 6 groups according to the combination of the main factors adhesive/resin cement (2 commercial brands) and radiant exposure (4, 16, 48, and 288 J/cm2). The posts were cemented and the PBS tested at 0.5 mm/min (n = 7). The NL (n = 3) was evaluated using SEM after immersion of specimens in 50% silver nitrate. Micro-Raman spectroscopy was performed to determine the in situ DC (n = 2). Data were analyzed by three-way repeated measures ANOVA and Tukey's post-hoc test (5%). RESULTS: PBS (MPa) showed a significant difference only for the middle third when an increase in radiant exposure from 4 to 16 J/cm2 or higher was used (p < 0.05). The NL (%) decreased significantly with increasing radiant exposure from 48 to 288 J/cm2 in the middle and apical thirds when compared to lower radiant exposure (p < 0.05). The radiant exposure of 288 J/cm2 significantly increased the DC (%) in the middle and apical thirds, compared the other radiant exposure values (p < 0.05). CONCLUSION: The increase in radiant exposure delivered to the cervical third of root canals during post cementation improved the adhesive performance of simplified etch-and-rinse adhesive systems in the apical and middle thirds.
Assuntos
Cavidade Pulpar/ultraestrutura , Cura Luminosa de Adesivos Dentários/métodos , Técnica para Retentor Intrarradicular/instrumentação , Doses de Radiação , Cimentos de Resina/efeitos da radiação , Dente Pré-Molar/ultraestrutura , Bis-Fenol A-Glicidil Metacrilato/química , Cimentação/métodos , Infiltração Dentária/classificação , Humanos , Teste de Materiais , Metacrilatos/química , Microscopia Eletrônica de Varredura , Polietilenoglicóis/química , Polimerização , Ácidos Polimetacrílicos/química , Poliuretanos/química , Cimentos de Resina/química , Coloração pela Prata , Análise Espectral Raman , Estresse Mecânico , Propriedades de Superfície , Ápice Dentário/ultraestruturaRESUMO
PURPOSE: The purpose of this study was to evaluate the effect of self-adhesive and self-etching resin cements on the bond strength of nonmetallic posts in different root regions. MATERIALS AND METHODS: Sixty single-rooted human teeth were decoronated, endodontically treated, post-space prepared, and divided into six groups. Glass-fiber (GF) posts (Exacto, Angelus) and fiber-reinforced composite (FRC) posts (EverStick, StickTeck) were cemented with self-adhesive resin cement (Breeze) (SA) (Pentral Clinical) and self-etching resin cement (Panavia-F) (SE) (Kuraray). Six 1-mm-thick rods were obtained from the cervical (C), middle (M), and apical (A) regions of the roots. The specimens were then subjected to microtensile testing in a special machine (BISCO; Schaumburg, IL, USA) at a crosshead speed of 0.5 mm/min. Microtensile bond strength data were analyzed with two-way ANOVA and Tukey's tests. RESULTS: Means (and SD) of the MPa were: GF/SA/C: 14.32 (2.84), GF/SA/M: 10.69 (2.72), GF/SA/A: 6.77 (2.17), GF/SE/C: 11.56 (4.13), GF/SE/M: 6.49 (2.54), GF/SE/A: 3.60 (1.29), FRC/SA/C: 16.89 (2.66), FRC/SA/M: 13.18 (2.19), FRC/SA/A: 8.45 (1.77), FRC/SE/C: 13.69 (3.26), FRC/SE/M: 9.58 (2.23), FRC/SE/A: 5.62 (2.12). The difference among the regions was statistically significant for all groups (p < 0.05). The self-adhesive resin cement showed better results than the self-etching resin cement when compared to each post (p < 0.05). No statistically significant differences in bond strengths of the resin cements when comparable to each post (p > 0.05). CONCLUSION: The bond strength values were significantly affected by the resin cement and the highest values were found for self-adhesive resin cement.
Assuntos
Colagem Dentária/métodos , Cavidade Pulpar/ultraestrutura , Técnica para Retentor Intrarradicular/instrumentação , Cimentos de Resina/química , Cimentação/métodos , Resinas Compostas/química , Materiais Dentários/química , Análise do Estresse Dentário/instrumentação , Vidro/química , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Distribuição Aleatória , Preparo de Canal Radicular/métodos , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração , Ápice Dentário/ultraestrutura , Colo do Dente/ultraestrutura , Dente não Vital/patologiaRESUMO
PURPOSE: To evaluate the effect of the insertion technique for resin cement and mechanical cycling on the bond strength between fiber posts and root dentin. MATERIALS AND METHODS: Sixty-four single-rooted bovine teeth were endodontically prepared to receive glass-fiber posts. The insertion of cement into the root canal was performed using one of the following techniques: POS, insertion with the post; LEN, the use of a lentulo-type drill; EXP, insertion with a straight-tip explorer; or CEN, the use of a Centrix syringe. Half of the specimens were mechanically cycled. All specimens were sectioned into slices of 1.8 mm for the push-out test and 0.5 mm for analysis of the cement layer quality. RESULTS: The insertion technique affected the interaction between factors (bond strength and mechanical cycling; p < 0.0001). Insertion of the Centrix syringe after mechanical cycling showed the highest bond values (13.6 ± 3.2 MPa). Group-to-group comparisons for baseline and cycled conditions indicated that mechanical cycling significantly influenced the bond strength (p < 0.0001) of the POS and CEN groups. The quality of the cement layer did not differ between the techniques when evaluated in the middle (p = 0.0612) and cervical (p = 0.1119) regions, but did differ in the apical region (p = 0.0097), where the CEN group had better layer quality for the two conditions tested (baseline and cycled). CONCLUSION: The use of the Centrix syringe improved the homogeneity of the cement layer, reducing the defects in the layer and increasing adhesive strength values to dentin, even after mechanical cycling.
Assuntos
Colagem Dentária , Cavidade Pulpar/ultraestrutura , Dentina/ultraestrutura , Técnica para Retentor Intrarradicular/instrumentação , Cimentos de Resina/química , Animais , Bis-Fenol A-Glicidil Metacrilato/química , Bovinos , Resinas Compostas/química , Análise do Estresse Dentário/instrumentação , Vidro/química , Teste de Materiais , Metacrilatos/química , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Distribuição Aleatória , Estresse Mecânico , Propriedades de Superfície , Seringas , Temperatura , Fatores de Tempo , Ápice Dentário/ultraestrutura , Dente não Vital/patologia , Água/químicaRESUMO
The aim of this study was to evaluate the effect of chlorine dioxide and various other more common irrigation solutions on the microhardness and surface roughness of root canal dentin. Fifty human maxillary central incisors were sectioned longitudinally and treated for 1 minute with 5 ml of the following aqueous solutions (v/v%): Group 1: 13.8% chlorine dioxide, Group 2: 17% ethylene diamine tetraacetic acid (EDTA). Group 3: 7% maleic acid, Group 4: 2.5% sodium hypochlorite (5 ml/min), Group 5: Saline (control). Specimens were subjected to microhardness and surface roughness testing. Chlorine dioxide and sodium hypochlorite reduced the microhardness more than other test agents. The highest surface roughness was produced with maleic acid. Chlorine dioxide should be used cautiously during chemomechanical preparation of the root canal system in order to prevent untoward damage to the teeth.
Assuntos
Compostos Clorados/farmacologia , Cavidade Pulpar/efeitos dos fármacos , Dentina/efeitos dos fármacos , Óxidos/farmacologia , Irrigantes do Canal Radicular/farmacologia , Cavidade Pulpar/ultraestrutura , Dentina/ultraestrutura , Ácido Edético/farmacologia , Dureza , Humanos , Maleatos/farmacologia , Teste de Materiais , Microscopia de Força Atômica , Cloreto de Sódio , Hipoclorito de Sódio/farmacologia , Ápice Dentário/efeitos dos fármacos , Ápice Dentário/ultraestruturaRESUMO
STATEMENT OF PROBLEM: The mechanical properties of the adhesive materials used in intraradicular treatments could vary according to the interaction between the restorative material and dentin substrate. An evaluation of these properties is essential to determine the success of the luting procedures performed on glass-fiber posts. PURPOSE: The purpose of this study was to evaluate the mechanical properties of dentin adhesives, resin cements, and the dentin that underlies the bonding interface in different thirds of intraradicular dentin. MATERIAL AND METHODS: Forty extracted, single-rooted human teeth were used in this study. After the endodontic treatment of the post spaces, the teeth were divided into 5 groups (n=8): Adper Single Bond 2 + RelyX ARC, Excite DSC + RelyX ARC, Adper SE Plus + RelyX ARC, RelyX Unicem, and Set. The hardness and elastic modulus values were measured at the adhesive interface in different thirds of the radicular dentin by using an ultramicrohardness tester. The data were subjected to 2-way ANOVA and the Fisher protected least significant difference test (α=.05). RESULTS: In the underlying dentin, the highest Martens hardness values were found in the apical region for all groups; the exceptions were the groups with the self-etching adhesive. In the adhesive layer, the highest Martens hardness values were obtained for the Adper SE Plus + RelyX ARC group; further, no statistical differences were found among the different regions for this group. RelyX ARC had the lowest Martens hardness and elastic modulus values in the apical regions when used with Adper Single Bond 2 and Adper SE Plus. No differences were found in the Martens hardness and elastic modulus values for the self-adhesive resin cement in the regions investigated. CONCLUSION: The mechanical properties of adhesive materials and the underlying dentin are influenced by the interaction between the two as well as by the depth of the analyzed intraradicular area.
Assuntos
Colagem Dentária , Cavidade Pulpar/ultraestrutura , Adesivos Dentinários/química , Dentina/ultraestrutura , Bis-Fenol A-Glicidil Metacrilato/química , Cimentos Dentários/química , Materiais Dentários/química , Módulo de Elasticidade , Vidro/química , Dureza , Humanos , Teste de Materiais , Metacrilatos/química , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Técnica para Retentor Intrarradicular/instrumentação , Cimentos de Resina/química , Preparo de Canal Radicular/métodos , Estresse Mecânico , Ápice Dentário/ultraestruturaRESUMO
AIMS: Comparative evaluation of cleaning efficacy of smear layer removal by different irrigating solutions such as 2.5% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) with 2.5% NaOCl, 10% citric acid with 2.5% NaOCl and 1% tetracycline Hydrochloride (HCl) with 2.5% NaOCl for smear layer removal in the apical third of root canal. SETTINGS AND DESIGN: In vitro material science study. MATERIALS AND METHODS: Seventy-five single rooted permanent maxillary central incisor teeth were subjected to standardized root canal instrumentation (crown down technique). The teeth were randomly divided into five groups with 15 teeth in each groups: (1) Normal saline (n = 15) (2) 2.5% NaOCl (n = 15) (3) 17% EDTA + 2.5% NaOCl (n = 15) (4) 10% citric acid + 2.5% NaOCl (n = 15) (5) 1.0% tetracycline HCL + 2.5% NaOCl (n = 15). After final irrigation, the teeth were prepared for scanning electron microscope analysis to evaluate the cleaning of apical third of radicular dentine to determine the presence or absence of smear layer. STATISTICAL ANALYSIS USED: The results were analyzed by nonparametric statistical analysis techniques. Kruskal-Wallis test, Mann-Whitney test and Chi-square tests were carried out. RESULTS: There was no significant statistical difference in the efficacy of smear layer removal when 2.5% NaOCl was compared with 17% EDTA with 2.5% NaOCl, 10% citric acid with 2.5% NaOCl and 1% tetracycline HCl with 2.5% NaOCl in apical third of root canals. CONCLUSIONS: The present study suggests that irrigating agents, citric acid and tetracycline HCl can be used as an alternative to EDTA for the removal of smear layer in endodontics.
Assuntos
Cavidade Pulpar/efeitos dos fármacos , Irrigantes do Canal Radicular/farmacologia , Camada de Esfregaço/ultraestrutura , Ácido Cítrico/farmacologia , Cavidade Pulpar/ultraestrutura , Dentina/efeitos dos fármacos , Dentina/ultraestrutura , Ácido Edético/uso terapêutico , Humanos , Incisivo/efeitos dos fármacos , Incisivo/ultraestrutura , Teste de Materiais , Microscopia Eletrônica de Varredura , Distribuição Aleatória , Preparo de Canal Radicular/instrumentação , Preparo de Canal Radicular/métodos , Hipoclorito de Sódio/farmacologia , Tetraciclina/farmacologia , Ápice Dentário/efeitos dos fármacos , Ápice Dentário/ultraestruturaRESUMO
OBJECTIVE: To evaluate morphological changes of the apical surface after root canal preparation with 1 mm beyond the apical foramen using ProTaper Universal (PTU) files, K3 files and Twisted files (TF), respectively. METHODS: Seventy teeth with a centered apical foramen and 70 teeth with a deviated apical foramen were included as group A and group B respectively. In each group, 20 teeth were randomly assigned for root canal preparation with PTU, K3 and TF files, respectively; the remaining 10 teeth were used as the control group without any preparation. The apical foramens were examined with scanning electronic microscopy. The foramen integrity damage (FID) and dentin defects (DDs) were noted and compared between different groups. RESULTS: FID and DD were significantly less in Group A. DDs was not found in the control group. Preparation with PTU, K3, and TF files caused FID in 6.67%, 10%, and 3.33% of teeth in the group A, and in 20%, 26.67%, and 10% in Group B, respectively. Preparation with PTU, K3, and TF files caused DD in 6.67%, 6.67%, and 3.33% of teeth in Group A, and in 23.33%, 26.67%, and 6.67% in Group B, respectively. PTU and K3 files produced more DDS than TF files. However, no significant difference was found between groups using PTU and K3 files. CONCLUSION: Rotary instrumentation caused less damage on the apical surface in foramencentered root canals than foramen-deviated root canals when working beyond the canal length. TF files had a tendency to produce less DDS compared with PTU or K3 files during over-instrumented root canals.
Assuntos
Ligas Dentárias/química , Cavidade Pulpar/ultraestrutura , Níquel/química , Preparo de Canal Radicular/instrumentação , Titânio/química , Ápice Dentário/ultraestrutura , Cavidade Pulpar/lesões , Dentina/lesões , Dentina/ultraestrutura , Desenho de Equipamento , Humanos , Incisivo/ultraestrutura , Maxila , Microscopia Eletrônica de Varredura , Preparo de Canal Radicular/métodos , Rotação , Ápice Dentário/lesões , TorqueRESUMO
This study aimed to evaluate, by scanning electron microscopy (SEM), the cleaning of canal walls with moderate curvature subjected to biomechanical preparation with different final diameters using apical negative pressure irrigation. Thirty-two mesiobuccal roots of molars were divided into 4 groups (n=8) according to the instrument's final diameter: GI: 30.02, GII: 35.02, GIII: 40.02 and GIV: 45.02. Irrigating procedure was performed at each change of instrument with 1% NaOCl using the Endovac system. Final irrigation was conducted with 17% EDTA for 5 min. The SEM photomicrographs were evaluated under 35× and 1000× magnification, by three calibrated examiners, in a double-blind design. Data were submitted to Kruskal-Wallis and Dunn's post hoc tests (α=0.05). Canals instrumented with 30.02 and 35.02 final diameters showed more debris, statistically different from the other groups (p<0.05). Comparing each root canal third, for the cervical and apical portions no statistically significant difference (p>0.05) was found among the four groups. Regarding the presence of smear layer, canals with 30.02 final diameter showed the highest scores, statistically different from the 45.02 group (p<0.05) and similar to the 35.02 and the 40.02 groups (p>0.05). Although none of the studied diameters completely removed debris and smear layer, it may be concluded that instrumentation with higher final diameters was more effective in cleaning the root canals with moderate curvature.
Assuntos
Cavidade Pulpar/ultraestrutura , Preparo de Canal Radicular/métodos , Camada de Esfregaço/ultraestrutura , Irrigação Terapêutica/métodos , Ápice Dentário/ultraestrutura , Método Duplo-Cego , Ácido Edético/administração & dosagem , Humanos , Microscopia Eletrônica de Varredura , Pressão , Irrigantes do Canal Radicular/administração & dosagem , Preparo de Canal Radicular/instrumentação , Hipoclorito de Sódio/administração & dosagem , Irrigação Terapêutica/instrumentação , Colo do Dente/ultraestrutura , VácuoRESUMO
Achieving apical foramen patency through surgical maneuvers during the biomechanical preparation of root canals is a goal sought by several schools. The aim of this study was to evaluate the deformation of the foramen as a result of using stainless steel hand files and nickeltitanium rotary instruments for achieving patency. Forty recently extracted dental roots with single canals were calibrated to a length of 18 mm and mounted on acrylic blocks to enable study maneuvers. Each foramen was observed and mapped using SEM (Phillips high vacuum) at x 100, using Golden Ratio software (Softonic). Endodontic surgical preparation was subsequently performed on all samples to 1 mm from the foramen using the Protaper rotary system up to instrument F3. The samples were then divided into two groups of twenty for apical patency maneuvers: Group A (manual patency) on which stainless steel Flexofile (MailleferSuiza) hand files gauge .10 were used, and Group B (rotary patency) on which NiTi Pathfile (DentsplyMailleferSuiza) rotary instruments gauge .13 at 150 rpm, were used. The foramina were examined again using SEM, measured, mapped and compared with the previous images. A scale was established to evaluate the observations. Results were analyzed using the Mann Whitney test, which showed no significant difference between groups (p=0.110). It is concluded that under the conditions of this study, surgical apical patency maneuvers using stainless steel manual files or nickel titanium rotary instruments produced different degrees of foramen deformation, with no significant difference between methods.
Assuntos
Cavidade Pulpar/anatomia & histologia , Preparo de Canal Radicular/instrumentação , Ápice Dentário/anatomia & histologia , Ligas Dentárias/química , Cavidade Pulpar/ultraestrutura , Ácido Edético/análogos & derivados , Ácido Edético/uso terapêutico , Desenho de Equipamento , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Níquel/química , Distribuição Aleatória , Irrigantes do Canal Radicular/uso terapêutico , Rotação , Hipoclorito de Sódio/uso terapêutico , Aço Inoxidável/química , Titânio/química , Ápice Dentário/ultraestruturaRESUMO
INTRODUCTION: The aim of this in vitro study was to compare the effectiveness of saline, 2.5% sodium hypochlorite, and 2% chlorhexidine, with or without passive ultrasonic irrigation (PUI), in debris removal from simulated canal irregularities within prepared root canals. METHODS: Ninety bovine lateral incisors were randomly divided into 3 main groups (n = 30) based on the irrigant and prepared with hand files attached to an oscillating handpiece (NSK, Tokyo, Japan) up to a size #80 K-file. Next, the teeth were split longitudinally, and a standardized groove was prepared into the apical third and filled with dentin debris. After the halves were reassembled, they were placed in a muffle. Each main group was randomly subdivided into 2 groups (n = 14) and was treated with different final irrigation protocols. In the sodium hypochlorite/PUI, chlorhexidine/PUI, and saline/PUI groups, the solution was ultrasonically activated 3 times for 20 seconds. In the remaining groups, PUI was not performed. Specimens were scored for debris removal and analyzed under a scanning electron microscope. RESULTS: An association was observed between the score of debris removal and protocols using PUI (P < .05). No association was observed between the scores of debris removal and the irrigants (P = .87). CONCLUSIONS: Final irrigation protocols that used PUI were more effective in removing debris from simulated canal irregularities into the apical third than those that did not use it.