Selected Endodontic Pathogens in the Apical Third of Infected Root Canals: A Molecular Investigation
José F. Siqueira, Jr., DDS, MSc, PhD, Isabela N. Rôças, DDS, MSc, Flávio R. F. Alves, DDS, and Kátia R. N. Santos, BS, MSc, PhD
Antibacterial Efficacy of Calcium Hydroxide and Chlorhexidine Gluconate Irrigants at 37°C and 46°C
Chris Evanov, DDS, Frederick Liewehr, DDS, MS, Thomas B. Buxton, PhD, and Anthony P. Joyce, DDS
Effect of the Wicking Behavior of Multifilament Sutures
T. R. Grigg, DMD, F. R. Liewehr, DDS, MS, W. R. Patton, DDS, MS, T. B. Buxton, PhD, and J. C. McPherson, PhD
Evaluation of the Incidence of Transportation after Placement and Removal of Calcium Hydroxide
Fernando Goldberg, DDS, PhD, Denise Alfie, DDS, PhD, and Marcela Roitman, DDS
Presence OF CXCR3-Positive Cells and IFN-Ч–Producing Cells in Human Periapical
Granulomas
Hiroaki Kabashima, DDS, PhD, Masahiro Yoneda, DDS, PhD, Hiroyoshi Nakamuta, DDS, PhD, Kengo Nagata, DDS, PhD, Ryoko Isobe, DDS, Noriko Motooka, DDS, and Katsumasa Maeda, DDS, PhD
Treatment Outcome in Endodontics: The Toronto study. Phases I and II: Orthograde Retreatment
Mahsa Farzaneh, DDS, MSc, Sarah Abitbol, DDS, MSc, and Shimon Friedman, DMD
Accuracy of the TCM Endo III Torque-Control Motor for Nickel-Titanium Rotary Instruments
Ghassan Yared, DDS, MSc, and Gajanan K. Kulkarni, DDS, MSc, PhD
Sealing Ability of One-Up Bond and MTA With and Without a Secondary Seal as Furcation Perforation Repair Materials
Ike Hardy, DMD, Frederick R. Liewehr, DDS, MS, Anthony P. Joyce, DDS, Kelli Agee, BS, and David H. Pashley, DMD, PhD
Unusual Anatomy of Permanent Maxillary Molars
João Vicente Baroni Barbizam, DDS, MSc, Rodrigo Gonçalves Ribeiro, DDS, MSc, and Mário Tanomaru Filho, DDS, PhD
Apical Microleakage of Root-End Cavities Prepared by CO2 Laser
Emin Esen, DDS, PhD, Oguz Yoldas, DDS, PhD, Mehmet Kürkçü, DDS, PhD, M. Cem Doğan, DDS, PhD, and Gülşah Seydaoğlu, MD, PhD
Combined Therapy in the Treatment of Dens Invaginatus: Case Report
Pedro Ortiz, DDS, Rebeca Weisleder, DDS, and Yolanda Villareal de Justus, DDS
Treatment of a Maxillary Molar in a Patient Presenting With Florid Cemento-Osseous Dysplasia: A Case Report
Matthew B. Tonioli, DDS, William G. Schindler, DDS, MS
Selected Endodontic Pathogens in the Apical Third of Infected Root Canals: A Molecular Investigation
José F. Siqueira, Jr., DDS, MSc, PhD, Isabela N. Rôças, DDS, MSc, Flávio R. F. Alves, DDS, and Kátia R. N. Santos, BS, MSc, PhD
Bacteria located at the apical portion of the root canals are conceivably in a strategic position to induce damage to the periradicular tissues and resulting inflammatory diseases. This study sought to investigate the prevalence of 11 selected putative endodontic pathogens in the apical third of infected root canals associated with periradicular lesions. The apical root portion of 23 extracted teeth with carious pulpal exposures and attached periradicular lesions was sectioned, and the root canals were sampled for microbiological investigation. DNA was extracted from the samples and analyzed for the presence of 11 bacterial species using a nested polymerase chain reaction assay. The results showed that Pseuramibacter alactolyticus occurred in 10 cases (44%), Treponema denticola in 6 (26%), Fusobacterium nucleatum in 6 (26%), Porphyromonas endodontalis in 4 (17%), Filifactor alocis in 2 (9%), Dialister pneumosintes in 1 (4%), Porphyromonas gingivalis in 1 (4%), and Tannerella forsythensis in 1 (4%). No sample yielded Prevotella intermedia, Prevotella nigrescens, or Campylobacter rectus. Of the samples examined, 17 were positive for at least 1 of the target species. Occurrence of these bacterial species in the apical third of infected root canals suggests that they can be involved in causation of periradicular lesions.
Antibacterial Efficacy of Calcium Hydroxide and Chlorhexidine Gluconate Irrigants at 37°C and 46°C
Chris Evanov, DDS, Frederick Liewehr, DDS, MS, Thomas B. Buxton, PhD, and Anthony P. Joyce, DDS
This study investigated the ability of two endodontic irrigants to eliminate Enterococcus faecalis from dentinal tubules, and whether their antimicrobial action was enhanced by heat. The lumens of disks prepared from extracted bovine roots were infected with E. faecalis and incubated for 72 h. Specimens were then filled with saline, 10% calcium hydroxide (Ca(OH)2), or 0.12% chlorhexidine gluconate (CHX) at 24°C or 46°C and incubated at 37°C or 46°C. The samples were then pulverized and plated to quantify residual bacteria. No statistical difference (p > 0.05) in bacterial growth was seen between the two saline groups, or between the two medication groups at a given temperature. CHX and Ca(OH)2 at either temperature produced significantly less growth than either saline group, and CHX or Ca(OH)2 at 46°C produced significantly less growth than either group at 37°C. Heat enhanced the antibacterial action of both experimental irrigants against E. faecalis, but heating saline produced no increase in bactericidal effect.
Effect of the Wicking Behavior of Multifilament Sutures
T. R. Grigg, DMD, F. R. Liewehr, DDS, MS, W. R. Patton, DDS, MS, T. B. Buxton, PhD, and J. C. McPherson, PhD
The purpose of this study was to compare the wicking propensity of multifilament sutures. Dexon II, Vicryl, and black silk suture (BSS) were dipped in saline or soaked for 48 h, then suspended on a microscope slide. Fluorescein isothiocyanate-dextran (FITC-D) was placed at the suture mid points, and its movement was observed using fluorescence microscopy. The experiment was repeated, replacing the FITC-D with mixture of S. salivarius and saline, incubating the suture specimens in culture medium, and evaluating microbial growth. Dipped sutures showed FITC-D movement in the Dexon II group only. All 48-h soaked sutures demonstrated FITC-D movement with significant (p < 0.005) differences in mean times: BSS 179 ± 42 s; Vicryl 120 ± 26 s; and Dexon II 32 ± 2 s. Dexon II suture demonstrated wicking of S. salivarius, whereas Vicryl and BSS did not (p < 0.05). These results suggest that BSS and Vicryl sutures do not wick as readily as Dexon II does.
Evaluation of the Incidence of Transportation after Placement and Removal of Calcium Hydroxide
Fernando Goldberg, DDS, PhD, Denise Alfie, DDS, PhD, and Marcela Roitman, DDS
The purpose of this in vitro study was to evaluate the incidence of apical transportation after the placement and removal of Ca(OH)2 in straight and curved root canals. Twenty maxillary central incisors (group A) and 20 mesiobuccal canals from mandibular molars (group B) were instrumented at the working length to a #45 file and #30 file, respectively. Postinstrumentation radiographs were taken with the corresponding final file inserted into the canal to the working length. Afterward, the root canals were filled with a Ca(OH)2 paste using Lentulo spirals, and the teeth incubated for 7 days. The Ca(OH)2 paste was then removed up to the working length using a #45 file for group A and a precurved #30 file for group B. Final radiographs were taken with the file inserted into the canal to the working length. Postinstrumentation and final radiographs were superimposed to evaluate the incidence of transportation. As expected, in group A (straight canals) no transportation was detected, whereas in group B (curved canals) 9 of 20 canals showed apical transportation (95% confidence interval, 23.1–68.5% transportation). Statistically significant differences were observed between groups A and B (p < 0.05).
Presence OF CXCR3-Positive Cells and IFN-Ч–Producing Cells in Human Periapical
Granulomas
Hiroaki Kabashima, DDS, PhD, Masahiro Yoneda, DDS, PhD, Hiroyoshi Nakamuta, DDS, PhD, Kengo Nagata, DDS, PhD, Ryoko Isobe, DDS, Noriko Motooka, DDS, and Katsumasa Maeda, DDS, PhD
In an attempt to understand further the balance between the types of helper T (Th) cells in human apical periodontitis, we examined the difference in the expression of the chemokine receptor and cytokine in samples obtained from human subjects by means of immunohistochemical methods. Chemokine receptor CXCR3-positive cells and IFN-Ч– producing cells were found to be present in human periapical granulomas, whereas chemokine receptor CCR3-positive cells and IL-4–producing cells could not be detected. By contrast, no factor expression was observed in a clinically healthy periodontal ligament serving as a negative control. Our findings suggest that Th1 cells may play an important role in the pathological process of local inflammation such as apical periodontitis.
Treatment Outcome in Endodontics: The Toronto study. Phases I and II: Orthograde Retreatment
Mahsa Farzaneh, DDS, MSc, Sarah Abitbol, DDS, MSc, and Shimon Friedman, DMD
The 4- to 6-year outcome of orthograde retreatment was assessed for Phases I and II of the Toronto Study. In total, 523 teeth in 444 patients were retreated. With 395 teeth lost to follow-up and 25 extracted, 103 teeth (34% recall) were examined by two independent, blinded, calibrated examiners for outcome: “healed” (absence of apical periodontitis, signs, or symptoms) or “diseased” (presence of apical periodontitis, signs, or symptoms). The “healed” rate (81%) differed significantly for preoperative apical periodontitis (absent, 97%; present, 78%) and perforation (absent, 89%; present, 42%). Logistic regression revealed an increased risk of disease for preoperative perforation and adequate root filling quality, and postoperative lack of definitive restoration (odds ratios = 26.5, 6.6, and 14.0, respectively). Without perforation, inadequate intraoperative root filling length was also identified (odds ratio = 6.8). This study suggested that apical periodontitis, although a strong predictor, was secondary to preoperative perforation and root filling quality, and to postoperative restoration, in predicting the outcome of retreatment.
Accuracy of the TCM Endo III Torque-Control Motor for Nickel-Titanium Rotary Instruments
Ghassan Yared, DDS, MSc, and Gajanan K. Kulkarni, DDS, MSc, PhD
The purpose of this study was to determine the torque output and examine the accuracy of five TCM Endo III torque control motors. A handpiece was attached to the motor and gripped with a vise. A 0.07 taper Orifice Shaper, size 50, was inserted in the handpiece. The instrument tip was clamped in a chuck connected to a torque sensor. Four torque settings were evaluated at 350 rpm. Ten tests were performed at each torque setting. A new instrument was used for each test. The means of the torque values generated by the motors at the different torque levels were analyzed using analysis of variance and post-hoc pairwise comparisons with the Bonferroni test. The actual torque values were significantly higher than the torque preset on the motor (p < 0.0001) and did not differ significantly among the motors (p > 0.05). The actual torque deviated from the preset torque. The usefulness of these motors is questionable.
Sealing Ability of One-Up Bond and MTA With and Without a Secondary Seal as Furcation Perforation Repair Materials
Ike Hardy, DMD, Frederick R. Liewehr, DDS, MS, Anthony P. Joyce, DDS, Kelli Agee, BS, and David H. Pashley, DMD, PhD
This study investigated the ability of One-Up Bond alone and mineral trioxide aggregate (MTA), with and without a secondary seal of One-Up Bond or Super-EBA to seal saucer-shaped perforation defects in human molars. Cusps were removed, roots were amputated, and endodontic therapy completed on 40 extracted teeth. A cylindrical hole was made in each tooth from the furcation area to the chamber, into which a section of steel tubing was cemented. Intracoronal saucer-shaped defects were created over the perforation. The teeth were restored with MTA, One-Up Bond, or MTA with a secondary seal of One-Up Bond or SuperEBA. The integrity of the seal was evaluated by fluid filtration. MTA alone leaked significantly more than One-Up Bond or MTA with either secondary seal at 24 h. At 1 month, MTA, MTA plus One-Up Bond, and One-Up Bond alone were equivalent.
Unusual Anatomy of Permanent Maxillary Molars
João Vicente Baroni Barbizam, DDS, MSc, Rodrigo Gonçalves Ribeiro, DDS, MSc, and Mário Tanomaru Filho, DDS, PhD
The purpose of this study was to show anatomical variations in permanent maxillary molars. Two clinical cases of four-rooted maxillary molars and a macroscopic study of an extracted tooth, showing a five-rooted maxillary molar, are presented.
Apical Microleakage of Root-End Cavities Prepared by CO2 Laser
Emin Esen, DDS, PhD, Oguz Yoldas, DDS, PhD, Mehmet Kürkçü, DDS, PhD, M. Cem Doğan, DDS, PhD, and Gülşah Seydaoğlu, MD, PhD
This in vitro study in extracted human teeth was designed to compare the degree of dye penetration of root-end cavities prepared by CO2 laser, ultrasonic retrotip, or rotary instrument. Eighty two human anterior teeth were prepared and obturated with laterally condensed gutta-percha and sealer. Root-end resection was performed at 90 degrees, 3 mm from apex. Root-end cavities were prepared by CO2 laser beam, ultrasonic retrotips, or bur and were filled with amalgam. The teeth were isolated and immersed in basic fuchsin at 36°C for 48 hours. The roots were split longitudinally and examined by a stereomicroscope. Leakage was quantified by linear measurement of dye penetration with the aid of image-analyzing software. Apical leakage in the CO2 laser group was significantly less than in the ultrasonic retrotip and bur groups. The difference between the ultrasonic and bur groups was insignificant. Based on the results of this in vitro study, application of CO2 laser for root-end cavity preparation appears to decrease the apical leakage.
Combined Therapy in the Treatment of Dens Invaginatus: Case Report
Pedro Ortiz, DDS, Rebeca Weisleder, DDS, and Yolanda Villareal de Justus, DDS
Dens invaginatus is an anomaly that has numerous complex forms. Whenever endodontic therapy involving such a tooth becomes necessary, the clinician must be aware of the various treatments available for proper care. We present a case report of a maxillary lateral incisor having the anomaly in which both nonsurgical and surgical treatment was performed.
Treatment of a Maxillary Molar in a Patient Presenting With Florid Cemento-Osseous Dysplasia: A Case Report
Matthew B. Tonioli, DDS, William G. Schindler, DDS, MS
A case report of a 49-year-old black woman with florid cemento-osseous dysplasia is presented. Endodontic treatment of a maxillary first molar and a general review of florid cemento-osseous dysplasia are presented. Treatment considerations including diagnosis, difficulty in radiographic interpretation, working length determination, and postoperative concerns are discussed.