Abstract Introduction The purpose of this study was to evaluate coronal tooth discoloration of ProRoot MTA (Dentsply Tulsa Dental, Johnson City, TN), white ProRoot MTA, EndoSequence Root Repair ...Material (Brasseler USA, Savannah, GA), MTA Angelus (Angelus Solucoes Odontologicas, Londrina, Brazil), and Biodentine (Septodont, Saint Maur des Fosses, France) when used in an ex vivo pulpotomy model. Methods Freshly extracted mandibular third molars were collected and stored in 1% chloramine-T solution. Teeth were randomly assigned into 6 groups ( n = 15) and stored individually in phosphate buffered saline at 37°C in 100% humidity. A standardized endodontic access was made in 5 groups. A 3-mm-thick increment of reparative material was placed on the pulpal floor, covered by glass ionomer, and the access opening restored with composite. Color (Commission Internationale de l'eclairage L*a*b*) was recorded with the Vita Easy Shade spectrophotometer (VITA Zahnfabrik, Bad Säckingen, Germany) on the midbuccal surface at baseline; after access preparation; after material placement; and then after 1, 7, 30, and 60 days. Changes in Commission Internationale de l'eclairage L*a*b* were measured for each experimental group and compared with ProRoot MTA (positive control) and no treatment (negative control) using the following equation: ΔE = (Li − L0*2 + ai − a0*2 + bi − b0*2 )1/2 . The mean results were analyzed within each group and between groups using the Friedman 2-way analysis post hoc test ( P < .05). Results There were no significant differences between white ProRoot MTA, MTA Angelus, and the positive control group. EndoSequence Root Repair Material and Biodentine produced significantly less discoloration than white ProRoot MTA, MTA Angelus, and ProRoot MTA. Conclusions Under the conditions of this study, EndoSequence and Biodentine had significantly less discoloration compared with white ProRoot MTA, MTA Angelus, and ProRoot MTA. The potential for discoloration may or may not correlate when materials are used clinically.
Abstract Introduction The purpose of this in vitro study was to compare the biocompatibility of a novel formulation of a silicone-based endodontic sealer GuttaFlow 2 (GF2; Coltène/Whaledent, ...Langenau, Germany) with the original (GFO) and fast-set (GFF) formulations of GuttaFlow and with an epoxy resin sealer, AHPlus Jet (AH+J; Dentsply, York, PA). Methods Sealers were set into 3 × 5.5 mm discs. Cell culture media was used to extract leachable products at 24 hours and 1, 2, and 4 weeks. Primary human periodontal ligament fibroblasts were incubated with sealer elutes for 24 hours and evaluated using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay and the calcein AM assay. Cell attachment was evaluated on set sealer that was either rinsed or unrinsed with cell media for 1 week. Statistical analysis was performed using the Student t test. Results Both calcein and 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assays revealed that periodontal ligament cell viability was reduced on AH+J at 1, 2, and 4 weeks compared with all GuttaFlow sealers. There were no differences in cell viability between the GuttaFlow samples, and all displayed high rates of cell survival at all time periods. After 2 hours, cell attachment to the rinsed GFO and GFF samples exceeded the control, and at 24 hours cell attachment on all GuttaFlow samples exceeded the control. AH+J sealers supported significantly less cell attachment when compared with all GuttaFlow sealers. Cell attachment to set sealers showed better cell attachment when rinsed compared with unrinsed. Conclusions GuttaFlow sealers were more biocompatible than AHJ in vitro. The novel GF2 displayed comparable biocompatibility with GFF and GFO.
Abstract Introduction Recent nickel-titanium manufacturing processes have resulted in an alloy that remains in a twinned martensitic phase at operating temperature. This alloy has been shown to have ...increased flexibility with added tolerance to cyclic and torsional fatigue. The aim of this study was to assess the effect of repeated simulated clinical use and sterilization on cutting efficiency and flexibility of Hyflex CM rotary files. Methods Cutting efficiency was determined by measuring the load required to maintain a constant feed rate while instrumenting simulated canals. Flexibility was determined by using a 3-point bending test. Files were autoclaved after each use according to the manufacturer's recommendations. Files were tested through 10 simulated clinical uses. For cutting efficiency, mean data were analyzed by using multiple factor analysis of variance and the Dunnett post hoc test ( P < .05). For flexibility, mean data were analyzed by using Levene's Test of Equality of Error and a general linear model ( P < .05). Results No statistically significant decrease in cutting efficiency was noted in groups 2, 5, 6, and 7. A statistically significant decrease in cutting efficiency was noted in groups 3, 4, 8, 9, and 10. No statistically significant decrease in flexibility was noted in groups 2, 3, and 7. A statistically significant decrease in flexibility was noted in groups 4, 5, 6, 8, 9, 10, and 11. Conclusions Repeated simulated clinical use and sterilization showed no effect on cutting efficiency through 1 use and no effect on flexibility through 2 uses.
Abstract Introduction This study compared images displayed on 1 desktop monitor, 1 laptop monitor, and 2 tablets for the detection of contrast and working length interpretation, with a null ...hypothesis of no differences between the devices. Methods Three aluminum blocks, with milled circles of varying depth, were radiographed at various exposure levels to create 45 images of varying radiographic density. Six observers viewed the images on 4 devices: Lenovo M92z desktop (Lenovo, Beijing, China), Lenovo Z580 laptop (Lenovo), iPad 3 (Apple, Cupertino, CA), and iPad mini (Apple). Observers recorded the number of circles detected for each image, and a perceptibility curve was used to compare the devices. Additionally, 42 extracted teeth were imaged with working length files affixed at various levels (short, flush, and long) relative to the anatomic apex. Observers measured the distance from file tip to tooth apex on each device. The absolute mean measurement error was calculated for each image. Analysis of variance tests compared the devices. Observers repeated their sessions 1 month later to evaluate intraobserver reliability as measured with weighted kappa tests. Interclass correlation coefficients compared interobserver reliability. Results There was no significant difference in perceptibility detection between the Lenovo M92z desktop, iPad 3, and iPad mini. However, on average, all 3 were significantly better than the Lenovo Z580 laptop ( P values ≤.015). No significant difference in the mean absolute error was noted for working length measurements among the 4 viewing devices ( P = .3509). Conclusions Although all 4 viewing devices seemed comparable with regard to working length evaluation, the laptop computer screen had lower overall ability to perceive contrast differences.
Abstract Introduction Recent innovative manufacturing techniques have produced nickel-titanium (NiTi) rotary instruments with reports of superior properties compared with standard NiTi files. These ...include Profile Vortex made from M-Wire (PV), Twisted Files (TF), and 10 Series files made from CM Wire (CM). Sterilization is recommended before use and is repeated if files are reused and/or carried forward between cases. The purpose for this study was to compare the effects of multiple autoclaving cycles on the torsional load resistance of these 3 new rotary endodontic files. Methods PV, TF, and CM files (n = 100; size 25/.04) were divided into 5 groups (n = 20). Files were steam autoclaved for 1, 2, 3, and 7 sterilization cycles. A control group was not subjected to autoclaving. Files were tested in a torsiometer in general accordance with ISO 3630-1 standards. Torsional load and degrees of rotation to failure were recorded. Mean data were analyzed by using Kruskal-Wallace/Dunn post hoc tests ( P < .05). Results Autoclave cycles had no significant overall effect on file performance for any of the instrument systems tested. PV and CM displayed significantly greater resistance to torsional load than TF ( P < .001) but were not different from each other ( P > .05). Angular deflection values for TF and CM were significantly higher than for PV ( P < .001), with TF demonstrating greater rotational distortion than CM ( P < .05). Conclusions Under the conditions of this study, repeated steam autoclaving did not affect torsional resistance for unused files of the systems evaluated. In addition, CM Wire files might have a combined advantage of greater torsional strength and high deformation before failure.
This study was designed to compare a warm gutta-percha obturation technique, Thermafil Plus (Tulsa Dental, Tulsa OK), with lateral condensation for the ability to adapt gutta-percha to the walls of a ...root canal system. An extracted sectioned and mounted maxillary central incisor had canal irregularities created and was subsequently subjected to multiple obturations using both techniques. Length of fill, replication to working length, number of artificial depressions replicated, quality of replications, number of voids, and general appearance of obturation were all evaluated using standardized criteria. Data evaluation consisted of a one-way analysis of variance on the same type defects between obturation groups followed by a Scheffé post-hoc test. A statistically significant difference was found between the groups in each category of evaluation. Gutta-percha using Thermafil was better able to flow into lateral spaces, had fewer voids, and replicated the surface of the root better. It also, however, was extruded out the apical foramen more than in the lateral condensation group.
Dens evaginatus (DE) is an uncommon dental anomaly, having been well documented since 1925. It occurs primarily in people of Asian descent and is exhibited by protrusion of a tubercle from occlusal ...surfaces of posterior teeth, and lingual surfaces of anterior teeth. Tubercles have an enamel layer covering a dentin core containing a thin extension of pulp. These cusp-like protrusions are susceptible to pulp exposure from wear or fracture because of malocclusion, leading to pulpal complications soon after eruption. Endodontic intervention of permanent teeth with immature roots is unpredic for inflamed pulps, and leaves a tooth with compromised root structure when treating necrotic pulps. Efforts to ensure root maturity have involved preventive or prophylactic treatment with varying degrees of pulp invasiveness. Treatment options have changed as technology and materials have improved. The goal is to review the literature and pathophysiology regarding DE, and present a new comprehensive treatment regimen, including a truly prophylactic approach without pulpal invasiveness. A case study of a mestizo with DE is documented. Treatment of four affected mandibular premolars exhibiting three distinct diagnostic categories will illustrate various aspects of the treatment protocol presented, and tooth morphology of the anomaly is shown to aid clinical recognition.
Endocyn, a pH-neutral solution of hypochlorous acid and hypochlorite has been developed for use as an endodontic irrigant. The purpose of this study was to evaluate the effect of Endocyn on human ...periodontal ligament (PDL) fibroblasts, rat osteosarcoma cells (UMR-106), and stem cells of the apical papilla (SCAP) compared with other commonly used endodontic irrigants.
To determine cytotoxicity, cells were exposed to various concentrations of Endocyn, 6% sodium hypochlorite (NaOCl), 17% EDTA, and 2% chlorhexidine for 10 minutes, 1 hour, or 24 hours. Cell survival was measured fluorescently using calcein AM. Endocyn also was tested for its ability to inhibit SCAP proliferation and alkaline phosphatase activity. Finally, SCAP transcript expression was examined via reverse-transcriptase polymerase chain reaction.
Endocyn was no more toxic to PDL and UMR cells than water for up to 24 hours. Endocyn concentrations of 50% were toxic to SCAP after 1 hour of exposure. Endocyn concentrations of >20% inhibited SCAP proliferation, whereas concentrations of ≥10% inhibited alkaline phosphatase activity. Exposure of SCAP to 10% Endocyn for 3 days did not alter most transcript expression, but did significantly reduce the expression of alkaline phosphatase, fibromodulin, and osteomodulin.
Endocyn was significantly less cytotoxic to PDL, UMR-106, and SCAP cells compared with other commonly used endodontic irrigants. High concentrations of Endocyn did inhibit some transcript expression and alkaline phosphatase activity, indicating a potential reduction in the osteogenic potential of stems cells exposed to Endocyn.
•Most endodontic irrigants are cytotoxic to stem cells of the apical papilla.•Endocyn is much less cytotoxic to stem cells of the apical papilla.•High concentrations of Endocyn may suppress mineralized tissue formation.
Bioceramic materials have shown biologic and physical properties favorable for regenerative treatment. A key to treatment success is an adequate restoration to prevent microleakage; however, research ...is limited regarding the bond strength between restorative and bioceramic materials used in regenerative procedures. This study compared the bond strength between 4 bioceramic materials and a dual-cure composite resin.
Eighty wells in Teflon (ePlastics, San Diego, CA) blocks were filled with bioceramic materials representing 4 groups: White ProRoot mineral trioxide aggregate (MTA) (Dentsply Tulsa Dental, Tulsa, OK), Biodentine (Septodont, Saint Maur des Fosses, France), EndoSequence Root Repair Material Fast Set Putty (Brasseler USA, Savannah, GA), and NeoMTA (Avalon Biomed Inc, Houston, TX). After allowing samples to set according to the manufacturers’ instructions, exposed surfaces of the bioceramic materials were prepared using ClearFil SE Bond (Kuraray America, Inc., New York, NY) followed by restoration with ClearFil DC Core Plus (Kuraray America, Inc.). To test shear bond strength, each block was secured in a universal testing machine, and the crosshead was advanced at 0.5 mm/min until fracture. Newton peak force was recorded and megapascals calculated followed by data comparison.
The mean shear bond strengths between ClearFil DC Core Plus and the bioceramic materials were as follows: White ProRoot MTA, 7.96 MPa; Biodentine, 9.18 MPa; EndoSequence Root Repair Material Fast Set Putty, 4.47 MPa; and NeoMTA, 5.72 MPa. White ProRoot MTA and Biodentine were statistically similar, with a higher stress bond strength than NeoMTA, which had a statistically greater bond strength than EndoSequence Root Repair Material. All these values were lower than typical bond strengths shown for dentin–composite resin bonding.
The choice of which bioceramic material to use in regenerative procedures should be based on factors other than the bond between that material and the overlying coronal resin restoration.
Limited field cone-beam computed tomography (CBCT) imaging has become a modality frequently used by endodontists to evaluate the teeth and surrounding tissues of their patients. Accurate image ...interpretation is vital to obtain needed treatment information as well as to discern coincidental findings that could be present. The goal of this study was to determine the accuracy of CBCT volume interpretation when performed by endodontists and endodontic residents.
Eighteen deidentified limited field CBCT scans were obtained and evaluated by an oral and maxillofacial radiologist and an endodontist experienced in reading CBCT images. Their collective findings were combined as the “gold standard” of interpretation for this investigation. Using standard CBCT software, 4 practicing endodontists and 5 second-year endodontic residents evaluated each scan and recorded any notable findings and whether or not each scan warranted referral to a radiology specialist. Their interpretations were then compared with the gold standard to determine accuracy and any significant differences among the groups.
The overall accuracy was 58.3% for endodontists and 64.3% for residents. Paired t tests showed no statistically significant differences in accuracy between the 2 groups for findings in teeth or in bone, but residents were significantly better for maxillary sinus findings. Endodontists agreed with the gold standard 38.9% of the time and residents 49.8% of the time on necessity of referral. The Cohen kappa coefficient showed moderate agreement between the groups.
Endodontists and residents had similar accuracy in CBCT scan evaluation. More training and experience are warranted for both groups in order to maximize image assessment accuracy.
•The ability of practicing endodontists and endodontic residents to accurately interpret limited field of view 3-dimensional images was evaluated.•Both groups showed approximately 60% accuracy overall, whereas residents were significantly more accurate for findings located in the maxillary sinus.
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