Journal of Endodontics

Does a Combination of Two Radiographs Increase Accuracy in Detecting Acid-induced Periapical Lesions and Does It Approach the Accuracy of Cone-Beam Computed Tomography Scanning?

Elif Soğur, Hans-Göran Gröndahl, B. Güniz Baksı, Ali Mert — 2011-12-08

Abstract: Introduction: The purpose of this study was to determine whether the use of a combination of 2 images (storage phosphor plates [SPPs] and F-speed films [Eastman Kodak, Rochester, NY]) with a 10° difference in horizontal beam angulation resulted in better detectability of chemically created periapical defects than when only 1 image was used and whether a detectability as good as that achieved by limited cone-beam computed tomography (LCBCT) scanning could be achieved.Methods: Lesions were created by 1, 1.5, and 2 hours of acid application apical to extracted teeth in jaw specimens. After repositioning, teeth were radiographed with Accu-I-Tomo LCBCT, Digora Optime SPP system, and F-speed films. The SPPs and films were exposed at 0° and 10° horizontal angulations. The diagnostic accuracy (Az) was compared using 2-way analysis of variance; pair-wise comparisons were performed using the post hoc t test. Kappa was used to measure interobserver agreement.Results: A combination of 2 exposures with a 10° difference in horizontal angulation caused an increase, although not statistically significant, in the accuracy of both films and SPPs for all acid durations (P > .05) compared with when only 1 exposure was used. The accuracy did not approach that of LCBCT.Conclusions: Using a combination of 2 exposures instead of 1 did not significantly increase the accuracy in detecting acid-induced lesions at the apices of single-rooted premolars. The accuracy of LCBCT was superior.

A Survey of Dental Residents’ Expectations for Regenerative Endodontics

2011-12-09

Abstract: Introduction: The objective was to survey a group of dental residents regarding their expectations for using regenerative endodontic procedures as part of future dental treatments.Methods: After institutional review board approval, the opinions of 32 dentists who were having postgraduate residency training to become specialists in a dental school were surveyed. The survey had 40 questions about professional status, ethical beliefs, judgment, and clinical practice.Results: It was found that 83.9% of dentists had no continuing education or training in stem cells or regenerative endodontic procedures. Results showed that 96.8% of dentists are willing to receive training to be able to provide regenerative endodontic procedures for their patients. Of the total group, 49.1% of dentists already use membranes, scaffolds, or bioactive materials to provide dental treatment. It was determined that 47.3% of dentists agree that the costs of regenerative procedures should be comparable with current treatments. It was also found that 55.1% of dentists were unsure whether regenerative procedures would be successful.Conclusions: Dentists are supportive of using regenerative endodontic procedures in their dental practice, and they are willing to undergo extra training and to buy new technology to provide new procedures. Nevertheless, dentists also need more evidence for the effectiveness and safety of regenerative treatments before they will be recommended for most patients.

The Variability of Electric Pulp Response Threshold in Premolars: A Clinical Study

2011-11-21

Abstract: Introduction: This study was designed to determine the variability of the electric pulp response threshold in premolars and the relationship between the response threshold and age.Methods: Ninety-seven volunteers were recruited, ranging from 20–72 years old. The volunteers were categorized into 6 age groups: group 1, 20–29 years; group 2, 30–39 years; group 3, 40–49 years; group 4, 50–59 years; group 5, 60-69 years; and group 6, 70–79 years. All intact premolars present in each dental arch were tested. Three sites (the tip of the buccal cusp, the center of the middle, and cervical third of the buccal surface) on each tooth crown were tested.Results: In total, 1965 measurements were done. A progressive increase of mean threshold value was observed from groups 1 to 6. The response threshold value showed significant differences among the 6 age groups. The effect of age was more intense in mandibular premolars. In first and second mandibular premolars the cusp tip required the lowest current to evoke a response. In maxillary premolars no significant differences among the sites were found. Also, the mean threshold value of the mandibular premolars was lower than that of the maxillary premolars in subjects of the same age, and the mean threshold value of the first premolars was lower than that of the second premolars. The buccal cusp tip of the first mandibular premolars responded more quickly than any other tested site.Conclusions: Age is related with higher response threshold values. The optimum site for testing the lower premolars is the buccal cusp tip.

Effects of 3-Dimensional Conformal or Intensity-modulated Radiotherapy on Dental Pulp Sensitivity during and after the Treatment of Oral or Oropharyngeal Malignancies

2011-11-16

Abstract: Introduction: Radiation therapy (RT) of malignant tumors in the head and neck area may have damaging effects on surrounding tissues. The aim of this investigation was to evaluate the effects of RT delivered by 3-dimensional conformal radiotherapy (3D-RT) or intensity-modulated radiotherapy (IMRT) on dental pulp sensitivity.Methods: Twenty patients with oral or oropharyngeal cancer receiving RT with 3D-RT or IMRT underwent cold thermal pulp sensitivity testing (PST) of 2 teeth each at 4 time points: before RT (TP1), the beginning of RT with doses between 30 and 35 Gy (TP2), the end of RT with doses between 60 and 70 Gy (TP3), and 4 to 5 months after the start of RT (TP4).Results: All 40 teeth showed positive responses to PST at TP1 (100%) and 9 at TP2 (22.5%; 3/16 [18.8%] for 3D-RT and 6/24 [25.0%] for IMRT). No tooth responded to PST at TP3 and TP4 (0%). A statistically significant difference existed in the number of positive pulp responses between different time points (TP1 through TP4) for all patients receiving RT (P ≤ .05), IMRT (P ≤ .05), and 3D-RT (P ≤ .05). No statistically significant differences in positive sensitivity responses were found between 3D-RT and IMRT at any time point (TP1, TP3, TP4, P = 1.0; TP2, P = .74). A statistically significant correlation existed between the location of the tumor and PST at TP2 for IMRT (P ≤ .05) but not for 3D-RT (P = .14).Conclusions: RT decreased the number of teeth responding to PST after doses greater than 30 to 35 Gy. The type of RT (3D-RT or IMRT) had no influence on the pulp responses to PST after the conclusion of RT.

Endodontic Application of Cone-Beam Computed Tomography in South Korea

Seonah Kim — 2011-10-31

Abstract: Introduction: This study aimed to investigate the incidence of cone-beam computed tomography (CBCT) associated with endodontic procedures during 2009 in South Korea and to retrospectively evaluate information from CBCT with large field of view (FOV), which is popular in South Korea.Methods: The Health Insurance Review and Assessment agency, which reviews all medical and dental expenses covered under the Korean National Health Insurance (NHI) system, was queried for data on the nationwide number of CBCTs associated with some treatment procedures. To compare digital periapical radiography and CBCT retrospectively, 470 roots of 257 root canal–infected teeth were enrolled.Results: In total, 13,209 cases of NHI-covered CBCT were performed in South Korea during 2009, excluding cases for implant restoration and orthodontics. In total, 1253 and 95 CBCT cases were combined with root canal length measuring and apicoectomy, respectively. In a retrospective comparison, CBCT with large FOV provided more information about the presence of apical periodontitis, distortion of cortical bone, and identification of root compared with digital periapical radiography.Conclusions: CBCT with large FOV is useful in nonsurgical endodontic treatment and provides more information compared with digital periapical radiography.

Clustering Behavior in Microbial Communities from Acute Endodontic Infections

2011-12-19

Abstract: Introduction: Acute endodontic infections harbor heterogeneous microbial communities in both the root canal (RC) system and apical tissues. Data comparing the microbial structure and diversity in endodontic infections in related ecosystems, such as RC with necrotic pulp and acute apical abscess (AAA), are scarce in the literature. The aim of this study was to examine the presence of selected endodontic pathogens in paired samples from necrotic RC and AAA using polymerase chain reaction (PCR) followed by the construction of cluster profiles.Methods: Paired samples of RC and AAA exudates were collected from 20 subjects and analyzed by PCR for the presence of selected strict and facultative anaerobic strains. The frequency of species was compared between the RC and the AAA samples. A stringent neighboring clustering algorithm was applied to investigate the existence of similar high-order groups of samples. A dendrogram was constructed to show the arrangement of the sample groups produced by the hierarchical clustering.Results: All samples harbored bacterial DNA. Porphyromonas endodontalis, Prevotella nigrescens, Filifactor alocis, and Tannerela forsythia were frequently detected in both RC and AAA samples. The selected anaerobic species were distributed in diverse small bacteria consortia. The samples of RC and AAA that presented at least one of the targeted microorganisms were grouped in small clusters.Conclusions: Anaerobic species were frequently detected in acute endodontic infections and heterogeneous microbial communities with low clustering behavior were observed in paired samples of RC and AAA.

Effect of Guided Tissue Regeneration on Newly Formed Bone and Cementum in Periapical Tissue Healing after Endodontic Surgery: An In Vivo Study in the Cat

2011-12-07

Abstract: Introduction: The purpose of this study was to evaluate the influence of anorganic bovine bone as a grafted biomaterial on newly formed bone and cementum in periapical regions after surgical endodontic treatment in cats.Methods: After inducing apical periodontitis in 9 cats, root canal and surgical endodontic treatment were performed on 72 roots of first and second maxillary premolars. Bone defects were treated with biomaterial particles + a membrane, biomaterial only, a membrane only, or left unfilled (control). Histomorphometry on nondecalcified sections were performed at 3 and 6 months after surgery. Analysis of variance with repeated measures was used within 2 and 3 subject factors to analyze newly formed bone, cementum, biomaterial conduction, and resorption.Results: At each time period, bone formation was greater at the grafted membrane-protected sites than in the grafted-unprotected sites. At 6 months, the bone area fraction at membrane nongrafted sites was greater than in the grafted-protected sites. The new cementum was significantly greater at 6 months than at 3 months and greater at the grafted membrane-protected sites over the unprotected ones at 6 months. Statistically, the grafted biomaterial, the membrane, and the time contributed significantly to the amount of new bone (P<.05) with no significant interaction. Biomaterial osteoconduction was significantly affected by the time. All 3 variables showed a significant interaction on new cementum.Conclusions: There was significantly more bone formation after surgical endodontic treatment when membrane and bone grafts were used as compared with bone grafts only or unfilled control sites. However, it appears that the key factor to the enhanced tissue regeneration is the membrane and not the grafted biomaterial.

Mineralized Tissue Formation by Bone Morphogenetic Protein-7–transfected Pulp Stem Cells

Xuechao Yang, Siyuan Zhang, Xin Pang, Mingwen Fan — 2011-12-08

Abstract: Introduction: Recombinant human bone morphogenetic protein-7 (BMP-7) is a well-established agent to induce bone and dentin formation. Little is understood until now whether BMP-7 could be used to genetically modify human dental pulp stem cells for tissue engineering applications.Methods: This study was to determine the feasibility of mineralized tissue formation from human dental pulp-derived stem cells (DPSCs) transfected with adenoviral-mediated human BMP-7 gene through in vitro and in vivo evaluations.Results: In vitro results of alkaline phosphatase, calcium content, and real-time polymerase chain reaction showed that BMP-7–transfected cells had the ability to differentiate towards the odontoblast phenotype and produce a calcified extracellular matrix. Transfected cell were seeded onto a porous ceramic scaffold and implanted subcutaneously in mice. Samples were retrieved after 4 and 8 weeks for histology evaluation. The results indicated that only the cultures with BMP-7 gene transfection showed obvious hard-tissue generation.Conclusions: Our data suggest that adenovirus-mediated BMP-7 expression can induce odontogenic differentiation of human DPSCs and show effectively mineralized tissue formation in vivo, which may provide support for gene therapy candidate of BMP-7 in dental tissue engineering.

Expressional Alterations of Fibrillin-1 during Wound Healing of Human Dental Pulp

2011-10-31

Abstract: Introduction: The degradation of fibrillins, the major constituents of microfibrils, is known to facilitate the release of active transforming growth factor-β (TGF-β), a signaling molecule contributing to mineralized tissue barrier formation in exposed dental pulps. To examine the involvement of fibrillins in the barrier formation, we examined the temporospatial expression of (1) genes and proteins of fibrillins and (2) factors possibly associated with fibrillin degradation and cytodifferentiation in exposed human pulps. Human pulp slice cultures were also examined for the role of fibrillins in mineralization.Methods: Clinically healthy pulps were mechanically exposed and capped with mineral trioxide aggregate. After 7 to 42 days, the teeth were processed for immunohistochemical and cytochemical staining of fibrillin-1, fibrillin-2, latent TGF-β-binding protein (LTBP)-1, matrix metalloproteinase-3 (MMP-3), alkaline phosphatase (ALP), and in situ hybridization of fibrillin-1. Pulp tissue slices cultured with β-glycerophosphate were analyzed for fibrillin-1, fibrillin-2, and ALP with the immunohistochemical/cytochemical staining and quantitative reverse-transcriptase polymerase chain reaction.Results: Fibrillin-1-immunoreactivity was seen until 7 days but turned into undetectable since 14 days in the pulpal area just beneath the exposure site. MMP-3-immunoreaction was transiently detected at 14 days. At 42 days when the mineralized barrier was evident, fibrillin-1-immunoreactivity and fibrillin-1 expression remained down-regulated. Fibrillin-2, LTBP-1, and ALP were constantly detected in the fibrillin-1–undetectable area. Pulp slices cultured with β-glycerophosphate showed mineralization with up-regulation of ALP and down-regulation of fibrillin-1.Conclusions: Degradation and down-regulation of fibrillin-1 expression took place during the mineralized tissue barrier formation in exposed pulps in vivo and β-glycerophosphate–induced pulpal mineralization in vitro.

Expression Analysis of Wound Healing Genes in Human Periapical Granulomas of Progressive and Stable Nature

2011-10-31

Abstract: Introduction: Wound healing process involves the activation of extracellular matrix components, remodeling enzymes, cellular adhesion molecules, growth factors, cytokines and chemokines genes. However, the molecular patterns underlying the healing process at the periapical environment remain unclear. Here we hypothesized that endodontic infection might result in an imbalance in the expression of wound healing genes involved in the pathogenesis of periapical lesions. Furthermore, we suggest that differential expression of wound healing markers in active and latent granulomas could account for different clinical outcomes for such lesions.Methods: Study samples consisted of 93 periapical granulomas collected after endodontic surgeries and 24 healthy periodontal ligament tissues collected from premolars extracted for orthodontic purposes as control samples. Of these, 10 periapical granulomas and 5 healthy periapical tissues were used for expression analysis of 84 wound healing genes by using a pathway-specific real-time polymerase chain reaction array. The remaining 83 granulomas and all 24 control specimens were used to validate the obtained array data by real-time polymerase chain reaction. Observed variations in expression of wound healing genes were analyzed according to the classification of periapical granulomas as active/progressive versus inactive/stable (as determined by receptor activator for nuclear factor kappa B ligand/osteoprotegerin expression ratio).Results: We observed a marked increase of 5-fold or greater in SERPINE1, TIMP1, COL1A1, COL5A1, VTN, CTGF, FGF7, TGFB1, TNF, CXCL11, ITGA4, and ITGA5 genes in the periapical granulomas when compared with control samples. SERPINE1, TIMP1, COL1A1, TGFB1, and ITGA4 mRNA expression was significantly higher in inactive compared with active periapical granulomas (P < .001), whereas TNF and CXCL11 mRNA expression was higher in active lesions (P < .001).Conclusions: The identification of novel gene targets that curb the progression status of periapical lesions might contribute to a more accurate diagnosis and lead to treatment modalities more conducive to endodontic success.

Effects of the Antioxidant Agent Tempol on Periapical Lesions in Rats with Doxorubicin-induced Cardiomyopathy

2011-12-22

Abstract: Introduction: Cardiovascular diseases have been associated with increased risk of endodontic complications. This study evaluated the effects of the antioxidant agent tempol on periapical lesions in rats with doxorubicin-induced cardiomyopathy in comparison with control animals.Methods: Forty male Wistar rats were divided into 4 groups: (1) naïve rats orally treated with saline solution (10 mL/kg, during 21 days after periapical lesion induction); (2) naïve rats treated with tempol (30 and 50 mg/kg, during 21 days after periapical lesion induction) by oral pathway; (3) rats with doxorubicin-induced cardiomyopathy treated with saline solution by oral route (10 mL/kg, from day 3 to day 10 after initiating treatment with doxorubicin); and (4) rats with doxorubicin-induced cardiomyopathy orally treated with tempol (30 and 50 mg/kg, from day 3 to day 10 after initiating treatment with doxorubicin). Periapical lesions were induced on the first right mandibular molar tooth. After 21 days of apical periodontitis induction, the animals were killed, and the mandibles were collected for radiographic and histologic analysis.Results: The oral administration of tempol (50 mg/kg) was able to significantly prevent the establishment of periapical lesions in either control animals or rats submitted to the model of doxorubicin-induced cardiomyopathy, according to radiographic and histologic evaluation. Nevertheless, the protective effects of tempol were virtually greater in control animals in comparison with doxorubicin-treated rats, as indicated by histologic inflammatory assessment, which might be related to the increased production of free radicals under cardiomyopathy.Conclusions: We provide novel evidence on the beneficial systemic effects of the antioxidant tempol on apical periodontitis in both control animals and rats with doxorubicin-elicited cardiomyopathy.

Comparison of the Effect of Various Irrigants on Apically Extruded Debris after Root Canal Preparation

Masoud Parirokh, Shahrzad Jalali, Ali Akbar Haghdoost, Paul Vincent Abbott — 2011-12-08

Abstract: Introduction: Several factors can influence the amount of apically extruded debris. The aim was to quantitatively compare the amount of debris extruded apically from root canals when 3 different irrigants were used during canal preparation with rotary instruments.Methods: Ninety-one extracted single-rooted human mandibular premolar teeth with straight root canals were used. The teeth were randomly divided into 1 control group (group 1, n = 4) and 3 experimental groups of 29 teeth each. Hero 642 instruments were used for root canal preparation in all teeth, and 3 different irrigants were used (group 2, 2% chlorhexidine; group 3, 5.25% sodium hypochlorite; group 4, 2.5% sodium hypochlorite). Seven Eppendorf tubes served as a second control group. Debris extruded from the apical foramen during root canal preparation was collected into preweighed Eppendorf tubes. The weight of the dry extruded debris was established by subtracting the preinstrumentation and postinstrumentation weight of the Eppendorf tubes for each group. The data obtained were analyzed by using one-way analysis of variance and Tukey honestly significant difference.Results: Group 3 (sodium hypochlorite 5.25%) had the highest amount of extruded debris, which was significantly different from the other groups (P < .05).Conclusions: The type of irrigant used can affect the amount of apically extruded debris. The 5.25% solution of sodium hypochlorite had the greatest amount of debris.

Dynamic Movement of Intracanal Gas Bubbles during Cleaning and Shaping Procedures: The Effect of Maintaining Apical Patency on Their Presence in the Middle and Cervical Thirds of Human Root Canals—An In Vivo Study

Jorge Vera, Ana Arias, Mónica Romero — 2011-12-08

Abstract: Introduction: The vapor lock effect has been shown to limit the penetration of irrigating solutions into the apical third of root canals both in vivo and in vitro; however, little attention has been given to gas bubbles in the remainder of the root canal system.Methods: Seventy-one human root canals were randomly divided into 4 groups. Apical patency was maintained in 2 groups in both small (PS) (n = 21) and big canals (PB) (n = 15) during shaping and cleaning procedures with a 10 K-file 1 mm beyond working length but not in the other 2 groups: no patency, small canals (NPS) (n = 19) and no patency, big canals (NPB) (n = 16). Irrigation was performed with 1 mL of a solution prepared with a radiopaque contrast medium and sodium hypochlorite 5.25%. Digital images were taken, and a calibrated reader determined the presence or absence of gas bubbles in the middle and cervical thirds of the root canal system.Results: When a patency file was not used, 40% of the root canals presented gas bubbles; when a patency file was used, 25% of the cases exhibited gas bubbles.Conclusions: The presence of gas bubbles in the middle and cervical thirds of the root canal system during cleaning and shaping procedures is a common finding regardless of whether a patency file was used, although maintaining apical patency significantly leads to minimizing the presence of gas bubbles in big canals (P < .05).

Chemical and Ultramorphologic Effects of Ethylenediaminetetraacetic Acid and Sodium Hypochlorite in Young and Old Root Canal Dentin

2011-12-08

Abstract: Objectives: The objectives of this study were to evaluate and compare the time-dependent chemical and ultramorphologic effects of ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) in young and old dentin.Methods: Sixty-four teeth scheduled for extraction were collected from young (<30 years) and old (>60 years) patients. In 48 teeth, the dentin was reduced to a powder state and treated with EDTA or EDTA + NaOCl for 1 and 10 minutes, respectively. X-ray diffraction analysis was used to determine the changes in the composition of dentin through dissolution of hydroxyapatite (HAp). In the remaining teeth (n = 16), the root canals were prepared, bisected, and subjected to the same time-dependent treatment regimens. The changes in the number and area of dentinal tubules were calculated by image analysis. The data were analyzed statistically by paired t test and one-way analysis of variance, followed by Tukey honestly significant difference test at P = .05.Results: In both young and old dentin, EDTA significantly decreased the HAp intensity at 1 and 10 minutes, whereas EDTA + NaOCl only decreased that of old dentin at 10 minutes. Pair-wise comparisons revealed that in old dentin, the reduction in HAp intensity after treatment with EDTA and EDTA + NaOCl was significantly greater at 10 minutes than at 1 minute, whereas in young dentin, a significant decrease was only observed in the EDTA/10-minute subgroup. Compared with their 1-minute counterparts, 10-minute treatment with EDTA + NaOCl significantly increased the tubular diameter and tubular area of old dentin. In young dentin, the tubular area and diameter values were not affected by treatment time (P > .05).Conclusions: In young root dentin, 10-minute treatment with EDTA + NaOCl does not significantly alter the chemical and ultramorphologic structure and thus appears to be unnecessary. In old dentin, extended treatment time with EDTA + NaOCl should be avoided owing to excessive demineralization and erosion. In both types of dentin, EDTA was not effective in complete removal of the smear layer.

The Challenge of C-shaped Canal Systems: A Comparative Study of the Self-Adjusting File and ProTaper

Michael Solomonov, Frank Paqué, Bing Fan, Yuval Eilat, Louis H. Berman — 2011-12-08

Abstract: Introduction: C-shaped canals are anatomic features that present the clinician with both diagnostic and operational challenges. The aim of this study was to compare the efficacy of the Self-Adjusting File (SAF; ReDent, Ra’anana, Israel) in shaping C-shaped canals with that of the rotary ProTaper file system (Dentsply-Maillefer, Ballaigues, Switzerland).Methods: Sixteen mandibular second molars and 4 maxillary second molars with C-shaped canals were obtained, originating from native Chinese population. They were divided into 2 equal groups of 10 teeth each, based on similar canal morphology as presented in preliminary micro–computed tomography–derived images. One group was shaped using the SAF, whereas the other was shaped using the ProTaper file system. Reconstructed micro–computed tomographic images before and after treatment were superimposed over each other, and the percentage of the canal wall unaffected by the procedure was calculated. Comparison of the 2 groups for this parameter was performed using the Student t test.Results: When treated with the SAF, 41% ± 14% of the canal walls remained unaffected by the procedure, whereas 66% ± 6% of the wall area was unaffected when using ProTaper, which was significantly higher than that of the SAF-treated group (P < .001).Conclusions: The SAF was more effective than the ProTaper file system in shaping the walls of C-shaped root canals.

Comparison between the Effect of Plasma and Chemical Treatments on Fiber Post Surface

2011-12-08

Abstract: Introduction: The aim of the present study was to evaluate the fiber post surface after plasma and usual treatments and the adhesion between treated fiber posts and Rely X Unicem resin cement (3M ESPE, St Paul, MN).Methods: Flat fiber posts were divided into 6 groups according to surface treatment: silane, hydrofluoric acid, hydrofluoric acid plus silane, plasma polymerization with argon, ethylenediamine plasma (EDA), and the control group. A goniometer was used to measure the contact angle between the groups with water or resin cement. Scanning electron microscopy and electron dispersive spectroscopy were used to examine the topography and chemical changes in the post surfaces after treatment. Push-out tests were performed using a universal testing machine to evaluate the adhesion strength between treated fiber posts and resin cement.Results: In the contact angle with water, the most hydrophilic surface was observed in samples treated with argon plasma, followed by treatments with silane and hydrofluoric acid plus silane. The hydrophobic characteristic was observed with EDA and hydrofluoric acid. The contact angle with dual resin cement showed lower values with argon and EDA, followed by silane and hydrofluoric acid plus silane. Electron dispersive spectroscopy analyses showed chemical modifications in the surface after different treatments although topographic changes were verified only with EDA plasma compared with the control. Push-out results did not show differences between groups compared with the control, except for EDA plasma treatment.Conclusions: Plasma treatment favored the wettability of the post surface by modifying it chemically. Adhesion improvement was only observed after EDA treatment.

Dentin Bond Strength of Two Mineral Trioxide Aggregate–based and One Epoxy Resin–based Sealers

2011-12-06

Abstract: Introduction: This study aimed at evaluating the bond strength to root dentin of 2 mineral trioxide aggregate (MTA)–based sealers (Endo-CPM sealer and MTA Fillapex) and of 1 epoxy resin–based sealer (AH Plus sealer).Methods: Forty-five extracted human teeth with single roots were prepared by using the step-back technique. Irrigation with 2.5% NaOCl and a final rinse with 17% ethylenediaminetetraacetic acid and distilled water were performed. Canals were filled by using Endo-CPM sealer, MTA Fillapex, or AH Plus sealer by means of the gutta-percha lateral condensation technique. After 7 days, the roots were sectioned perpendicularly to its long axis, and the push-out test was carried out. The data were analyzed by using the Kruskal-Wallis and Dunn post hoc tests.Results: Endo-CPM sealer showed the highest values of bond strength to root dentin (8.265 MPa) (P < .05). The values of push-out test were similar for MTA Fillapex (2.041 MPa) and AH Plus (3.034 MPa).Conclusions: On the basis of the findings presented herein and within the limitations of this study, Endo-CPM sealer presented advantages when a post preparation was required. MTA Fillapex presented acceptable resistance to dislodgement, which was similar to that observed in samples filled with AH Plus sealer.

Experimental Evaluation on the Influence of Autoclave Sterilization on the Cyclic Fatigue of New Nickel-Titanium Rotary Instruments

2011-11-21

Abstract: Introduction: The purpose of this study was to evaluate the effect of autoclave sterilization on cyclic fatigue resistance of rotary endodontic instruments made of traditional and new nickel-titanium (NiTi) alloys.Methods: Four NiTi rotary endodontic instruments of the same size (tip diameter 0.40 mm and constant .04 taper) were selected: K3, Mtwo, Vortex, and K3 XF prototypes. Each group was then divided into 2 subgroups, unsterilized instruments and sterilized instruments. The sterilized instruments were subjected to 10 cycles of autoclave sterilization. Twelve files from each different subgroup were tested for cyclic fatigue resistance. Means and standard deviations of number of cycles to failure (NCF) and fragment length of the fractured tip were calculated for each group, and data were statistically analyzed (P < .05).Results: Comparing the results between unsterilized and sterilized instruments for each type of file, differences were statistically significant (P < .05) only between sterilized and unsterilized K3XF files (762 versus 651 NCF). The other instruments did not show significant differences (P > .05) in the mean NCF as a result of sterilization cycles (K3, 424 versus 439 NCF; Mtwo, 409 versus 419 NCF; Vortex, 454 versus 480 NCF). Comparing the results among the different groups, K3 XF (either sterilized or not) showed a mean NCF significantly higher than all other files (P < .05).Conclusions: Repeated cycles of autoclave sterilization do not seem to influence the mechanical properties of NiTi endodontic instruments except for the K3 XF prototypes of rotary instruments that demonstrated a significant increase of cyclic fatigue resistance.

Efficacy of the Self-Adjusting File System on Cleaning and Shaping Oval Canals: A Microbiological and Microscopic Evaluation

2011-12-07

Abstract: Introduction: The shaping ability of root canal instruments is determined by a complex interrelationship of parameters such as cross-sectional design and the ability to remove debris and the smear layer. The self-adjusting file (SAF) consists of a hollow, flexible instrument in the form of a compressible, thin-walled, pointed cylinder. The aim of this study was to compare the SAF with the ProTaper rotary file system, evaluating debris and smear layer removal and the presence of bacteria by using microbiological and scanning electron microscopy (SEM) evaluation.Methods: Fifty maxillary premolars were inoculated with Enterococcus faecalis for 30 days and then randomly distributed into 2 groups. Group 1 was prepared with ProTaper rotary instruments and irrigated with 30-gauge side-vented needles. Group 2 was prepared by using the SAF system with continuous irrigation. Bacteriologic samples were taken before and after preparation. All samples were then longitudinally split and analyzed under scanning electron microscopy. The scoring was carried out by 3 blinded evaluators.Results: In group 1, 40% of samples had negative cultures with postinstrumentation samples taken with paper points (S2a) and 45% with postinstrumentation dentin samples (S2b). In group 2, 20% of samples had negative cultures with S2a and 15% with S2b. Intragroup analyses evaluating the reduction in the number of colony-forming units (CFUs) from S1 to S2a and S2b demonstrated both preparation techniques were highly effective (P < .01). Further reduction of CFUs was observed when comparing S2a and S2b in group 1 (P < .05), whereas no difference was observed in group 2. Intergroup analysis demonstrated a statistically significant difference of CFUs at S2a and S2b (P < .05). SEM scores were consistent with the microbiology findings.Conclusions: The SAF system does not allow control of the apical enlargement, thus limiting the ability of the irrigants to achieve effective and predictable disinfection.

Dentinal Microcrack Formation during Root Canal Preparations by Different NiTi Rotary Instruments and the Self-Adjusting File

Oguz Yoldas, Sehnaz Yilmaz, Gokhan Atakan, Cihan Kuden, Zeynep Kasan — 2011-12-07

Abstract: Introduction: The purpose of this study was to compare dentinal microcrack formation while using hand files (HFs), 4 brands of nickel-titanium (NiTi) rotary files and the self-adjusting file.Methods: One hundred forty mandibular first molars were selected: 20 teeth were left unprepared and served as control, and the remaining 120 teeth were divided into 6 groups. HFs, HERO Shaper (HS; Micro-Mega, Besancon, France), Revo-S (RS, Micro-Mega), Twisted File (TF; SybronEndo, Orange, CA), ProTaper (PT, Dentsply Maillefer), and SAFs were used to prepare the 2 mesial canals. Roots were then sectioned 3, 6, and 9 mm from the apex, and the cut surface was observed under a microscope and checked for the presence of dentinal microcracks.Results: The control, HF, and SAF groups did not show any microcracks. In roots prepared with the HS, RS, TF, and PT, dentinal microcracks were observed in 60%, 25%, 44%, and 30% of teeth, respectively. There was a significant difference between the control/HF/SAF group and the 4 NiTi rotary instrument groups (P .005).Conclusions: All rotary files created microcracks in the root dentin, whereas the SAF file and hand instrumentation presented with satisfactory results with no dentinal microcracks.

Comparison of In Vivo and In Vitro Readings When Testing the Accuracy of the Root ZX Apex Locator

2011-12-07

Abstract: Introduction: The purpose of the study was to compare the accuracy of the Root ZX electronic apex locator (J Morita Corp, Tokyo, Japan) between an in vivo and an in vitro model.Methods: The working length (WL) was determined electronically for 46 root canals of human teeth with a 15 K-file using both in vitro (n = 23) and in vivo (n = 23) models. The files were fixed at the WL. The apical 4 mm of each canal was trimmed to expose the file tip. The samples were observed under a scanning electron microscope, and the distance from the file tip to the point 0.5 mm coronal to the major foramen (the final WL) was measured. The data were analyzed using the Student t test, and significance was set at P ≤ .05.Results: The statistical analysis revealed no significant differences between the in vivo group and in vitro group with respect to the accuracy of the Root ZX device in determining the final WL. The mean distance from the final WL to the file tip was 0.23 ± 0.39 mm for the in vivo group and 0.29 ± 0.32 mm for the in vitro group. In determining the final WL, the Root ZX was accurate 78.3% of the time to ±0.5 mm and 100% of the time to ±1 mm in the in vivo group, whereas it was accurate 74% of the time to ±0.5 mm and 100% of the time to ±1 mm in the in vitro group.Conclusions: No statistically significant differences were observed between the in vivo group and the in vitro group.

Dentin Moisture Conditions Affect the Adhesion of Root Canal Sealers

2011-11-15

Abstract: Introduction: The purpose of this study was to evaluate the effects of intraradicular moisture conditions on the push-out bond strength of root canal sealers.Methods: Eighty root canals were prepared using rotary instruments and, thereafter, were assigned to 4 groups with respect to the moisture condition tested: (1) ethanol (dry): excess distilled water was removed with paper points followed by dehydration with 95% ethanol, (2) paper points: the canals were blot dried with paper points with the last one appearing dry, (3) moist: the canals were dried with low vacuum by using a Luer adapter for 5 seconds followed by 1 paper point for 1 second, and (4) wet: the canals remained totally flooded. The roots were further divided into 4 subgroups according to the sealer used: (1) AH Plus (Dentsply-Tulsa Dental, Tulsa, OK), (2) iRoot SP (Innovative BioCeramix Inc, Vancouver, Canada), (3) MTA Fillapex (Angelus Indústria de Produtos Odontológicos S/A, Londrina, Brasil), and (4) Epiphany (Pentron Clinical Technologies, Wallingford, CT). Five 1-mm-thick slices were obtained from each root sample (n = 25 slices/group). Bond strengths of the test materials to root canal dentin were measured using a push-out test setup at a cross-head speed of 1 mm/min. The data were analyzed statistically by two-way analysis of variance and Tukey tests at P = .05.Results: Irrespective of the moisture conditions, iRoot SP displayed the highest bond strength to root dentin. Statistical ranking of bond strength values was as follows: iRoot SP > AH Plus > Epiphany ≥ MTA Fillapex. The sealers displayed their highest and lowest bond strengths under moist (3) and wet (4) conditions, respectively.Conclusions: The degree of residual moisture significantly affects the adhesion of root canal sealers to radicular dentin. For the tested sealers, it may be advantageous to leave canals slightly moist before filling.

The Effect of Acidity on Dislodgment Resistance of Mineral Trioxide Aggregate and Bioaggregate in Furcation Perforations: An In Vitro Comparative Study

Ahmed Abdel Rahman Hashem, Suzan Abdul Wanees Amin — 2011-10-31

Abstract: Introduction: The aim of this study was to compare the effect of acidic environment on the dislodgement resistance of mineral trioxide aggregate (MTA) and Bioaggregate (Innovative BioCeramix, Vancouver, Canada) when used as perforation repair materials.Methods: Eighty, human, mandibular molars were used. Perforations were made in the furcation of each molar and enlarged to #4 Pesso drills. After perforation repair, specimens of each material were randomly divided into 4 groups (n = 10) according to storage media and time: group A: phosphate-buffered saline (PBS) (pH = 7.4) for 4 days, group B: acetic acid (pH = 5.4) for 4 days, group C: PBS for 34 days, and group D: acetic acid (pH = 5.4) for 4 days followed by exposure to PBS for 30 days. Dislodgment resistance was then measured using a universal testing machine, and then the specimens were vertically split to examine the perforated dentin wall using scanning electron microscopy.Results: MTA resisted dislodgement more efficiently than BA after 4 days in PBS (P < .05). The dislodgment resistance of MTA was significantly reduced (P < .05) after exposure to acetic acid, whereas BA was not affected (P > .05). There was an increase in the dislodgment resistance with the increase in the storage time to 34 days (P < .01). After 34 days, there was a statistically significant difference among groups; the MTA D group had significantly the highest bond strength, and the BA D group D had the lowest (P < .05).Conclusions: MTA is more influenced by acidic pH than BA. Storage for 30 days in PBS can reverse the affected bond of MTA by the acidic environment.

Dentinal Tubule Infection as the Cause of Recurrent Disease and Late Endodontic Treatment Failure: A Case Report

Adalberto R. Vieira, José F. Siqueira, Domenico Ricucci, Weber S.P. Lopes — 2011-12-05

Abstract: Introduction: This article describes a case of recurrent post-treatment apical periodontitis and late failure after endodontic retreatment performed in a single visit.Methods: The patient presented with a tooth exhibiting inadequate endodontic treatment and a large periradicular lesion that extended laterally to the root. Retreatment was performed in a single visit and involved chemomechanical preparation using 5.25% NaOCl as the irrigant and root canal obturation by Schilder’s vertical compaction technique. A large lateral canal was radiographically revealed after obturation. After 2 years, the lesion was no longer radiographically discernible, a condition that was confirmed 9 years after retreatment procedures. Nonetheless, after 12 years, radiographs revealed recurrent disease. Apical surgery was performed, and the root apex, including the area of the large lateral canal, was resected with care to maintain the lesion attached to it. The biopsy specimen was subjected to histopathologic and histobacteriologic analyses.Results: Longitudinal sections of the apical root specimen revealed a heavy dentinal tubule infection surrounding the area of the lateral canal. Bacteria were not found in any other area of the specimen. No other possible reason for the inflammatory periradicular lesion, such as root fracture, coronal leakage, or foreign-body reaction, was evident.Conclusions: A persistent intraradicular infection caused by bacteria located within dentinal tubules is the most reasonable explanation for resurgence of the apical periodontitis lesion. This case report stresses the importance of attaining proper disinfection of the root canal system for a predictable long-term outcome of the treatment.

Endodontic Management in a Patient with Vitamin D–resistant Rickets

Charalampos Beltes, Evanthia Zachou — 2011-12-12

Abstract: Introduction: Hypophosphatemic vitamin D–resistant rickets (VDRRs) is a metabolic bone disease caused by abnormalities in the vitamin D receptive system or in phosphate and calcium metabolism. This condition occurs in growing skeleton affecting bone and dentin mineralization, resulting in systemic and oral manifestations.Methods: A 15-year-old boy was referred to the private clinic for endodontic treatment in #9. His medical history revealed VDRR disease. The dental findings were multiple periapical lesions in several teeth without obvious reason such as caries or trauma. The radiographic examination showed short roots, enlarged pulp chambers with longer pulp horns, thin dentin and enamel, missing or poorly defined lamina dura, and abnormalities in the cementoenamel junction, all pathognomonic features of the disorder. Conservative endodontic treatment was completed in all teeth with pulp necrosis and rarefactions.Results: A 6-month, 1-year, and 2-year follow-up radiographic examination revealed progressive improvement with bone reconstruction without any clinical symptoms.Conclusions: Early diagnosis, conventional treatment, and continuous radiographic examination are important factors in improving dental alterations in patients with VDRRs.

Successful Local Anesthesia for Restorative Dentistry and Endodontics

Nikita B. Ruparel — 2011-12-12

This book presents practical information that is clinically valuable to any dentist who provides local anesthesia. It caters to a wide audience: students, graduate residents, and practicing clinicians alike. It has numerous user-friendly features including one-liners after each subsection that summarize the take-home message of that topic, flow charts, photographs, data, and illustrations that make understanding each topic easy and convenient. The book’s 7 chapters provide all-inclusive descriptions of topics related to local anesthesia in dentistry.

Associate Registry

2012-02-01

CE Registry

2012-02-01

AAE Foundation Donor Honor Roll

2012-02-01

President's Message

2012-02-01

News

2012-02-01

Editorial Board

2012-02-01

Journal of Endodontics

Does a Combination of Two Radiographs Increase Accuracy in Detecting Acid-induced Periapical Lesions and Does It Approach the Accuracy of Cone-Beam Computed Tomography Scanning?

A Survey of Dental Residents’ Expectations for Regenerative Endodontics

The Variability of Electric Pulp Response Threshold in Premolars: A Clinical Study

Effects of 3-Dimensional Conformal or Intensity-modulated Radiotherapy on Dental Pulp Sensitivity during and after the Treatment of Oral or Oropharyngeal Malignancies

Endodontic Application of Cone-Beam Computed Tomography in South Korea

Clustering Behavior in Microbial Communities from Acute Endodontic Infections

Effect of Guided Tissue Regeneration on Newly Formed Bone and Cementum in Periapical Tissue Healing after Endodontic Surgery: An In Vivo Study in the Cat

Mineralized Tissue Formation by Bone Morphogenetic Protein-7–transfected Pulp Stem Cells

Expressional Alterations of Fibrillin-1 during Wound Healing of Human Dental Pulp

Expression Analysis of Wound Healing Genes in Human Periapical Granulomas of Progressive and Stable Nature

Effects of the Antioxidant Agent Tempol on Periapical Lesions in Rats with Doxorubicin-induced Cardiomyopathy

Comparison of the Effect of Various Irrigants on Apically Extruded Debris after Root Canal Preparation

Dynamic Movement of Intracanal Gas Bubbles during Cleaning and Shaping Procedures: The Effect of Maintaining Apical Patency on Their Presence in the Middle and Cervical Thirds of Human Root Canals—An In Vivo Study

Chemical and Ultramorphologic Effects of Ethylenediaminetetraacetic Acid and Sodium Hypochlorite in Young and Old Root Canal Dentin

The Challenge of C-shaped Canal Systems: A Comparative Study of the Self-Adjusting File and ProTaper

Comparison between the Effect of Plasma and Chemical Treatments on Fiber Post Surface

Dentin Bond Strength of Two Mineral Trioxide Aggregate–based and One Epoxy Resin–based Sealers

Experimental Evaluation on the Influence of Autoclave Sterilization on the Cyclic Fatigue of New Nickel-Titanium Rotary Instruments

Efficacy of the Self-Adjusting File System on Cleaning and Shaping Oval Canals: A Microbiological and Microscopic Evaluation

Dentinal Microcrack Formation during Root Canal Preparations by Different NiTi Rotary Instruments and the Self-Adjusting File

Comparison of In Vivo and In Vitro Readings When Testing the Accuracy of the Root ZX Apex Locator

Dentin Moisture Conditions Affect the Adhesion of Root Canal Sealers

The Effect of Acidity on Dislodgment Resistance of Mineral Trioxide Aggregate and Bioaggregate in Furcation Perforations: An In Vitro Comparative Study

Dentinal Tubule Infection as the Cause of Recurrent Disease and Late Endodontic Treatment Failure: A Case Report

Endodontic Management in a Patient with Vitamin D–resistant Rickets

Successful Local Anesthesia for Restorative Dentistry and Endodontics

Associate Registry

CE Registry

AAE Foundation Donor Honor Roll

President's Message

News

Editorial Board

Table of Contents