Relationships between Caries Bacteria, Host Responses, and Clinical Signs and Symptoms of Pulpitis
Chin-Lo Hahn, PhD, DDS, Frederick R. Liewehr, DDS, MS
Knowledge of caries bacteria and the inflammatory responses they elicit in the dental pulp is prerequisite to our understanding of the pathogenesis of pulpitis. Recent advances in immunology and neurophysiology can now explain some of the clinical manifestations of pulpitis. The purpose of this review is twofold. The first purpose is to review the literature of the caries microflora, the host immune responses they elicit, and how they do so. The relationship between both proinflammatory and anti-inflammatory cytokines and pulpitis is discussed. The proinflammatory properties of lipoteichoic acid, which is a common virulence factor among Gram-positive bacteria such as those found among the caries bacteria, are reviewed. The second purpose is to review how bacteria and their metabolites, as well as pulpal immune and inflammatory reactions to them, modify the pain sensation in pulpitis.
How Useful Is Root Canal Culturing in Predicting Treatment Outcome?
Chankhrit Sathorn, DClinDent, Peter Parashos, PhD, Harold H. Messer, PhD
Microbial control—fundamental to healing of apical periodontitis—is central to endodontic practice. The effectiveness of antibacterial measures is generally monitored (in clinical research studies) by microbiological root canal sampling (MRS), which is often used as a predictor for healing. This article addresses the question of the extent to which positive or negative cultures at time of obturation are able to predict treatment outcome. To date only one small clinical study has attempted to relate the treatment outcome to intraradicular bacterial status (p = 0.025, Fisher’s exact test): the strength of the association was not great, with a wide confidence interval (odds ratio = 6.8; 95% CI: 1.5 to 32). The extent to which current canal sampling techniques accurately reflect the bacterial status of the canal space must also be taken into account. False positive and negative cultures may adversely affect the performance of MRS. These conditions emphasize how potentially error-prone MRS can be. As currently practiced, intracanal sampling techniques suffer from deficiencies that limit their predictive value. This article in no way questions the role of intracanal bacteria in causing apical periodontitis, nor the central role of bacterial control in endodontic treatment. Rather, it emphasizes the need for more detailed clinical studies of bacterial status and healing, as well as refinement of techniques for microbial sampling of canals.
An Epidemiologic Study of Tooth Retention After Nonsurgical Endodontic Treatment in a Large Population in Taiwan
Shih-Chung Chen, DDS, Ling-Huey Chueh, DDS, MS, Chuhsing Kate Hsiao, PhD, Miao-Yu Tsai, PhD, Shih-Chang Ho, DDS, Chun-Pin Chiang, BDS, DMSc
In this study, tooth retention and untoward events were assessed over a 5-year follow-up period for 1,557,547 teeth receiving nonsurgical root canal treatment (NSRCT) in Taiwan in 1998. We found that 1,446,199 (92.9%) of teeth receiving NSRCT were retained in the oral cavity 5 years after treatment and that a total of 111,348 (7.1%) of the studied teeth were extracted. Untoward events occurred in 159,680 (10.3%) teeth during the 5-year follow-up period. Of this small subpopulation, nonsurgical retreatment was performed for 50,587 teeth (31.7%), apical surgery was performed on 4,502 (2.8%) teeth, and extractions were performed on 104,591 (65.5%) teeth. Approximately 40% of the nonsurgical retreatments and 81% of the apical surgeries occurred in the first follow-up year. However, the yearly incidence of tooth extractions was nearly even within the 5-year study period. We conclude that NSRCT is a valuable dental procedure because of the high rate (92.9%) of tooth retention 5 years after NSRCTs in Taiwan.
Prevalence and Quality of Endodontic Treatment in the Northern Manhattan Elderly
Chia-Yi Chen, DDS, Gunnar Hasselgren, DDS, PhD, Neill Serman, DDS, Mitchell S.V. Elkind, MD, MS, FAAN, Moïse Desvarieux, MD, PhD, Steven P. Engebretson, DMD, MS, MS§
Pulpitis results in significant morbidity among the elderly, particularly in underserved communities. We collected panoramic oral radiographs from 244 (mean age 67) participants of the Northern Manhattan Study, a prospective cohort study of stroke risk in a multiethnic urban population. Radiographs were evaluated for missing teeth, caries, restorations, periodontal bone loss, adequacy of endodontic treatment, and periapical radiolucencies. In the study 206 subjects were dentate (mean 17.1 teeth). 5.1% of teeth had periapical radiolucencies, and 4.8% had been endodontically treated; 37.5% of endodontically treated teeth had periapical radiolucencies. Teeth with restorations, periodontal bone loss, pulpotomy, and inadequate root canal filling had a significantly higher occurrence of periapical radiolucency (p < 0.05). Among all root filled teeth, only 26% were deemed satisfactory. We conclude that apical periodontitis is widely prevalent and the technical standard of root fillings is poor in this cohort. There is a substantial need for improved dental care among the northern Manhattan elderly.
KAI-1 Protein Expression in Odontogenic Cysts
Giovanna Iezzi, DDS, PhD, Adriano Piattelli, MD, DDS, Luciano Artese, MD, Gaia Goteri, MD, Massimiliano Fioroni, DDS, Corrado Rubini, MD
The KAI-1 tumor suppressor gene is widely distributed in normal tissues and its down-regulation may be correlated with the invasive phenotype and metastases in several different epithelial tumors. The aim of the present study was an evaluation of KAI-1 expression in radicular cysts (RC), follicular cysts (FC), orthokeratinized keratocysts (OOKC), and parakeratinized keratocysts (POKC). Eighty-five odontogenic cysts, 28 RC, 22 FC, and 35 OKC (16 OOKC, 19 POKC) were selected. All the POKC were negative and only four of 16 of the OOKC were positive for KAI-1. On the contrary, all RC and FC cases were positive and immunoreactivity for KAI-1 was detected throughout all the layers of the cyst epithelium. The lack of KAI-1 expression in POKC could help to explain the differences in the clinical and pathologic behavior of OKC and, according to what has been reported for epithelial tumors, could be related to the increased aggressive behavior and invasiveness of OKC.
Microscopic Periradicular Surgery: Perioperative Predictors for Postoperative Clinical Outcomes and Quality of Life Assessment
Mian K. Iqbal, BDS, DMD, MS, Samuel I. Kratchman, DDS, Garrett M. Guess, DDS, Bekir Karabucak, DMD, MS, Syngcuk Kim, DDS, PhD
The authors report on data from a self-assessment questionnaire filled out by 199 patients undergoing periradicular microscopic surgery at two private endodontic offices and at graduate endodontic clinics of the University of Pennsylvania. Regression analysis was performed using pain and swelling as dependent variables and age, sex, type of teeth, location, periapical lesion, and remedication as independent variables. Pain and swelling were significantly related to females and younger patients (p < 0.05). The results supported Etodolac as a pre- and postoperative analgesic and use of antibiotics restricted to high-risk patients. Maximum pain and swelling were reported at night and day 1 of the surgery, respectively. Generally, swelling was more often reported than pain. Surgeries in anterior maxilla were related to more pain and swelling. A majority of the patients (67%) rated surgical endodontics more pleasant than expected and found it less painful (46%) or the same (38%) as nonsurgical treatment. The results also point out that patients in general have negative beliefs and limited knowledge about periradicular surgery.
TRPM2 Immunoreactivity Is Increased in Fibroblasts, but not Nerves, of Symptomatic Human Dental Pulp
Kevin C. Rowland, PhD, Courtney B. Kanive, DMD, Jason E. Wells, PhD, John F. Hatton, DMD
Transient receptor potential (TRP) channels function in diverse processes such as acting as second messenger systems, regulating of ionic concentrations, and aiding in thermoception. TRPM2 channels, members of the melastatin subfamily, mediate calcium influx in response to oxidative stress but during pathological states facilitate hyperexcitability and cellular necrosis via calcium excitotoxicity. We hypothesized that TRPM2 channel expression is upregulated in pulpal tissue of symptomatic teeth with signs of irreversible pulpitis. TRPM2 channel expression was significantly increased in pulp from clinically diagnosed symptomatic teeth compared with pulp from asymptomatic teeth. Additionally, increased TRPM2 expression in symptomatic pulp was the result of increased immunoreactivity in fibroblasts, whereas neural expression of TRPM2 was absent. We provide a possible mechanism explaining the association between TRPM2 channel expression with pain and necrosis. We suggest that TRPM2 channel antagonists could be administered in attempts to inhibit the progression of or even reverse pulpal degradation.
Radiopacity Evaluation of New Root Canal Filling Materials by Digitalization of Images
Mário Tanomaru-Filho, PhD, Érica Gouveia Jorge, MSc, Juliane Maria Guerreiro Tanomaru, PhD, Marcelo Gonçalves, PhD
The aim of this study was to evaluate the radiopacity of five root canal filling materials (AH Plus, Intrafill, Roeko Seal, Epiphany, and EndoRez). Following the International Organization of Standardization 6876/2001, five circular specimens (10 × 1 mm) were made from each material. After the material set, radiographs were made using occlusal film and a graduated aluminum step-wedge varying in thickness from 2 to 16 mm. The dental X-ray unit (GE1000) was set at 50 Kvp, 10 mA, 18 pulses/second, and distance of 33.5 cm. The radiographs were digitized, and the radiopacity was compared with the aluminum step-wedge, using WIXWIN-2000 software (Gendex). Data (mm Al) were analyzed using ANOVA and Tukey tests. AH Plus and Epiphany were the most radiopaque materials (9.8 and 8.8 mm Al, respectively), followed by EndoRez (7.2 mm Al). Roeko Seal and Intrafill presented the lowest radiopacity values (5.7 and 6.1 mm Al, respectively). Although the materials evaluated demonstrated different radiopacities, all had values above the minimum recommended by the International Organization of Standardization.
Effects of Diode Laser (810 nm) Irradiation on Root Canal Walls: Thermographic and Morphological Studies
Adriana da Costa Ribeiro, MSc, Gessé Eduardo Calvo Nogueira, PhD†, João Humberto Antoniazzi, PhD, Andreas Moritz, PhD, Denise Maria Zezell, PhD
This study investigated the thermal effects and the morphological changes after diode laser irradiation (810 nm) of root canals. Samples were irradiated at 2.5 W, 1,989 W/cm2 (group 2) and 1.25 W, 10 Hz, 994 W/cm2 (group 3), with group 1 being the control group of nonirradiated samples. The temperature rise was evaluated using an infrared thermographic camera, and the morphological changes were assayed by scanning electron microscopy (SEM). The SEM images revealed closed dentinal tubules, especially at the apical regions when compared with the control samples. The maximum temperature variations at the apical region were analyzed, and the resulting 95% confidence intervals of the medians (Wilcoxon) ranged from 1.6 to 8.6°C (group 2) and from 1.2 to 3.3°C (group 3). The results suggest that the diode laser can be used for endodontic purposes and show that the method is safe for periodontal tissues at the investigated parameters.
Comparison of Removal Times of Thermafil Plastic Obturators Using ProFile Rotary Instruments at Different Rotational Speeds in Moderately Curved Canals
Alexander Royzenblat, DDS, MS, Gary G. Goodell, DDS, MS, MA
The purpose of this study was to compare the time required for removal of small Thermafil plastic carriers in moderately curved MB roots of mandibular molars using the ProFile rotary system at 300 and 1,500 rpm. MB roots of 40 mandibular molars were instrumented and obturated with size 30 Thermafil plastic obturators. Teeth were divided into two groups. In group 1, sizes 55 to 25 ProFile 0.04-taper instruments were used in a crown-down manner at 300 rpm. In group 2, size 25 ProFile 0.04-taper instruments were used at 1,500 rpm. Time of carrier removal and the number of instrument separations were recorded. The Student’s t test demonstrated a significant difference between groups: 4 minutes 12 seconds for group 1 and 1 minute 28 seconds for group 2 (p < 0.001). However, a trend for greater separation of instruments was found with the higher rpm group.
Interfacial Adaptation of Adhesive Materials to Root Canal Dentin
Jorge Perdigão, DMD, MS, PhD⁎, Maria M. Lopes, BS†, George Gomes, DMD‡
Extracted single-rooted maxillary teeth were endodontically treated and filled with gutta-percha/AH-26 (GP), Resilon points/RealSeal (RS), AdheSE DC/Multicore Flow (ADH, self-etch control), or Excite DSC/Multicore Flow (EXC, total-etch control). Specimens were analyzed with electron microscopy using three methods: (a) field emission scanning electron microscopy (FESEM) of the interface; (b) transmission electron microscopy (TEM) of the interface; and (c) FESEM of the material fitting surface. The three adhesive materials (RS, ADH, and EXC) formed a dentin hybrid layer, which nonetheless resulted in interfacial separation. Gaps were more frequent for GP, which did not hybridize dentin. The fitting surfaces exhibited resin tags at all levels for EXC. Tags were less frequent with ADH, especially in the apical third. For RS, resin tags were rare and virtually absent from the apical half, whereas GP did not form tags. Despite the hybridization, a tight seal of the root canal is difficult to achieve because of the complexity and the mechanical challenge of the substrate.
Effect of Surface Treatments on Tensile Bond Strength and on Morphology of Quartz-fiber Posts
Camillo D’Arcangelo, DDS, Maurizio D’Amario, DDS, Gianni Domenico Prosperi, DDS, Marco Cinelli, DDS, Mario Giannoni, MD, DDS, Sergio Caputi, MD, DDS
This study evaluated the effect of three post surface treatments on quartz-fiber post (a) retention and (b) morphology. A control group was not treated. Different treatments were performed for the other posts: silanization; etching by hydrofluoric acid 9.5%; sandblasting with 50 μm Al2O3. Two specimens of each group were submitted to a qualitative scanning electron microscopy (SEM) analysis. Remaining specimens were luted in prepared root canals (n = 10) and retentions were determined using a universal testing machine. Retentive post bond strengths were significantly enhanced with any tested post surface pretreatment. The increase in retentive strength was more remarkable in sandblasted and etched posts. Significant changes of post surfaces were SEM observed after different conditioning treatments.
A Comparison of LightSpeed LS1 and LightSpeed LSX NiTi Rotary Instruments in Apical Transportation and Length Control in Simulated Root Canals
Mian K. Iqbal, BDS, DMD, MS, Brian Banfield, DMD, Amanda Lavorini, DDS, Benedict Bachstein
In a major design change LightSpeed Technologies Inc. has replaced the U-shape blade design with a spade-shape design in LightSpeed LSX root canal rotary instruments. A double-digital radiographic technique was used to compare apical transportation (AT) and length control (LC) between the two instrument designs. Thirty simulated plastic root canals were instrumented by each rotary system. Digital radiography and AutoCAD 2007 were used to determine the central axes of files at 20, 35, 50, and 70 ISO sizes. By superimposition of central axes with a baseline at size 20, the degree of AT was measured at 0, 1, and 3 mm from working length (WL). The distance from file tips to set WL indicated any loss of LC. ANOVA test showed no significant differences between groups with respect to the degree of AT or LC. No instrument separation was noted. The results indicate that newly designed Lightspeed LSX instruments maintain the same effectiveness regarding AT and LC as that of the LightSpeed LS1 instruments.
Sealing Properties of Mineral Trioxide Aggregate Orthograde Apical Plugs and Root Fillings in an In Vitro Apexification Model
Rebecca L. Martin, BS, Francesca Monticelli, DDS, MSc, PhD, William W. Brackett, DDS, MSD, Robert J. Loushine, DDS, Roy A. Rockman, DDS, Marco Ferrari, DDS, PhD, David H. Pashley, DDS, PhD, Franklin R. Tay, BDSc(Hons), PhD
One-visit mineral trioxide aggregate (MTA) apexification is gaining in popularity over the use of calcium hydroxide barriers. This study examined the sealing properties of two MTA apexification procedures using an in vitro apexification model. White MTA was introduced into instrumented single-rooted canals with standardized artificially created open apices to form 3- to 5-mm-thick orthograde apical plugs or complete orthograde fillings of the root segments. The remaining canal spaces in the former group were backfilled with thermoplasticized gutta-percha without a sealer. A Flodec fluid filtration device was used to record fluid flow across filled root canals at 48 hours and after 4 weeks of immersion in phosphate-buffered saline (PBS). Although MTA root fillings exhibited a better seal than MTA apical plugs at 48 hours, seals of these two groups were not significantly different after 4 weeks. Interaction of MTA with PBS may result in apatite deposition that improves the seal of MTA apical plugs with time.
Modes of Failure of ProTaper Nickel–Titanium Rotary Instruments after Clinical Use
Xi Wei, MS, MDS, Junqi Ling, PhD, Jin Jiang, PhD, Xiangya Huang, MS, Lu Liu, MD
This study was to investigate the mode of fracture of ProTaper rotary instruments after clinical use and to compare stereomicroscopy with scanning electron microscopy (SEM) to determine which is the better method for establishing the mode of material failure. In all, 100 fractured ProTaper instruments were examined under stereomicroscope for the presence of plastic deformation along the cutting edge near the fracture site. Fractographic and longitudinal examinations were carried out at high-power magnification with SEM. Stereomicroscopy revealed 88 flexural cases and 12 torsional cases. Fractomicrographs verified 91 flexural cases with fatigue striations and three torsional cases with circular abrasion marks. Six instruments showed characteristics of both flexural and torsional failures. Cracks, microcracks, and pittings were common findings on longitudinal micrographs. Our study demonstrated that inspecting the fractured surface at high-power magnification by SEM is a better method to reveal the mode of NiTi rotary instrument separation.
Impact of Lubricant Parameters on Rotary Instrument Torque and Force
Claudia Boessler, Dr Med Dent, Ove A. Peters, PD, Dr Med Dent, MS, FICD, Matthias Zehnder, Dr Med Dent, PhD
In the current study, the impact of lubricant parameters on simulated root canal instrumentation was investigated. Using size 30 ProFile .06 instruments in milled artificial root canals in human dentin, the effects of sodium hypochlorite (1% NaOCl) and a chelator (18% etidronic acid) in aqueous irrigants on maximum torque, full torsional load, and maximum force values were gauged using a torque testing platform. Furthermore, the impact of the time a chelating lubricant was exposed to dentin as well as its galenic form (aqueous vs. gel-type) on the above outcome variables was evaluated. Aqueous lubricants significantly (p < 0.05, ANOVA, Newman–Keuls) reduced all outcome variables compared to dry conditions. The incorporation of a chelator further reduced these values (p < 0.05), whereas hypochlorite behaved similar to water. The chelator effect was immediate and did not increase with time. An aqueous lubricant was more beneficial than a gel-type counterpart.
A Comparison of Three Ni-Ti Rotary Instruments in Apical Transportation
Homan Hossein Javaheri, DDS, Ghasem Hossein Javaheri, DDS, MSD
The purpose of this study was to compare apical transportation and changes in canal curvature of three nickel-titanium (Ni-Ti) rotary instruments: Hero 642, RaCe, and ProTaper. Mesiobuccal canals of 60 maxillary first molars (with angles of curvature between 25 degrees and 35 degrees) were prepared with a torque-control, low-speed engine. Canals were prepared using the crown-down technique to the size of #30. Using a radiographic platform, reproducible preinstrumentation and postinstrumentation radiographs were taken. A computer analysis allowed magnification and superimposition of the images. The central axes of initial and final instruments were radiographically superimposed to measure transportation at 1 mm from WL. Data were analyzed using repeated-measures ANOVA. A statistically significant difference in apical transportation was found in ProTaper group. The results suggest that ProTaper file system be implemented in combination with other less tapered more flexible systems, like RaCe, in preparing curved canals.
Analysis of Defects in ProTaper Hand-operated Instruments after Clinical Use
Ya Shen, DDS, PhD, Zhuan Bian, DDS, PhD, Gary Shun-pan Cheung, MDS, MSc, PhD, Bin Peng, DDS, PhD
The purpose of this study was to analyze the type and location of defects observed in ProTaper for Hand Use (PHU) instruments after routine clinical use. We analyzed a total of 401 PHUs discarded from an endodontic clinic over a 17-month period. Those failed instruments were examined on the lateral and fractographic surface by scanning electron microscope. Of the 86 PHUs that showed discernible defects, 28 were intact but partially unwound, and 58 were fractured (36 because of shear and 22 from fatigue failure). The primary characteristic of shear failure was the presence of a skewed dimple and/or tear ridge, a typical pattern developed because of a combination of various loads. Nearly 74% of the instruments with defects exhibited shear damage. About three-quarters of the instrument fractures occurred in the apical one-third of the canal, mostly in molars. The results of this study indicated that most PHU instruments fail because of either shear or fatigue.
Comparison of Apical Leakage between Canals Filled with Gutta-Percha/AH-Plus and the Resilon/Epiphany System, When Submitted to Two Filling Techniques
Denusa Moreira Veríssimo⁎, Mônica Sampaio do Vale, MS, PhD†, André Jalles Monteiro, PhD‡
The purpose of this study was to compare the level of apical leakage between canals filled with gutta-percha/AH-Plus (GP) and the Resilon/Epiphany System (RES), when submitted to two filling techniques. Seventy extracted teeth were instrumented and randomly divided into four experimental groups in accordance with the material and techniques used [lateral condensation and Hybrid technique (HT)] and two control groups. After 7 days in an oven (37°C, 100% humidity), the teeth were immersed in India ink and cleared. Leakage was measured by the NIH imageJ program. With respect to the presence of leakage, there was no difference between the filling techniques (p > 0.05), but there was a statistically significant difference when RES was compared with GP (p < 0.05), which leaked more than RES. With RES, leakage was confined to the apical third and HT could be used to thermoplasticize RES with satisfactory results.
Effect of Bismuth Oxide Radioopacifier Content on the Material Properties of an Endodontic Portland Cement–based (MTA-like) System
Kristian S. Coomaraswamy, BDS, Philip J. Lumley, BDS, FDSRCPS, PhD, Michael P. Hofmann, PhD
The effect of bismuth oxide (Bi2O3) radioopacifier addition on the material properties of an endodontic Portland cement–based system were investigated. Increasing Bi2O3 content from 0 to 10 wt % resulted in a deterioration of mechanical strength from 82 to 40 MPa, decreasing gradually on further addition to 29 MPa for 40 wt %. Bi2O3 content increase also gradually increased the relative porosity of the set material from 15 to 31%. Strong linear correlationships were found for increases in relative porosity, dry and strut densities, and Bi2O3 content increase. Material constants, such as critical flaw size, were found to alter drastically with Bi2O3 addition and remained constant with further increase, thus affecting the potential longevity of the endodontic model system. The cement system was also found to be comparable in composition and strength to commercial MTA but had lower porosity because of the better workability of the Portland cement component.
A Comparative Study of Contact Angles of Four Different Root Canal Sealers
Evangelos G. Kontakiotis, DDS, PhD, Giorgos N. Tzanetakis, DDS, Alexios L. Loizides, DDS, MSc
The present in vitro study was conducted with the aim of evaluating and comparing the contact angles of three different types of root canal sealers—Roth 801, AH26, and RSA RoekoSeal—with the contact angle of a newly developed silicone-based root canal filling material (Gutta-Flow) on dentin and gutta-percha surfaces at two different time periods. The contact angles were determined mathematically by measuring software and were calculated from base width and height of the droplet meniscus of each sealer. Under the conditions of this study, Roth 801 and AH26 recorded lower values of contact angles when root dentin surface was used as the substrate. RSA RoekoSeal and Gutta-Flow seem to spread similarly on dentin and gutta-percha surfaces, although the contact angles of these silicone-based sealers were found to be significantly higher than the contact angles of Roth 801 and AH26 sealers. According to these findings, it can be concluded that conventional root canal sealers (Roth 801 and AH26) may passively have the potential for better wettability of dentin and gutta-percha surfaces than that of silicone-based sealers (RSA RoekoSeal and Gutta-Flow). This fact means that Roth 801 and AH26 may have a better spreading capacity under clinical conditions on the root canal walls and gutta-percha surfaces. Application of a sufficient load during lateral or vertical compaction seems to be needed for RSA RoekoSeal and Gutta-Flow to satisfactorily wet gutta-percha and dentin under clinical conditions.
Influence of Fiber-post Translucency on the Degree of Conversion of a Dual-cured Resin Cement
André Luís Faria e Silva, DDS, MS, Vanessa Gallego Arias, DDS, PhD, Luís Eduardo Silva Soares, DDS, PhD, Airton Abrahão Martin, Phys, PhD, Luís Roberto Marcondes Martins, DDS, PhD
This study evaluated the degree of conversion of one dual-cured resin cement when used to lute fiber posts with different translucencies. To measure the degree of conversion, polyvinylsiloxane molds were prepared to simulate root canals. The posts, Aestheti-Post or Light-Post, were cemented in these molds and, after photoactivation, were removed to obtain the resin cement spectrum by FT-Raman spectroscopy. Spectra were acquired at three depths: superficial, medium, and deep. For Light-Post, the resin cement at deep depth showed the lowest degree of conversion and no significant difference in degree of conversion was found between the other depths. For Aestheti-Post, the superficial depth presented a higher degree of conversion values than those in the medium and deep depths, which were not significantly different from each other. Light-Post exhibited a higher degree of conversion than that of Aestheti-Post only at medium depth. Light-Post effectiveness regarding the degree of conversion is dependent on the depth.
In Vitro Leakage Associated with Three Root-filling Techniques in Large and Extremely Large Root Canals
Johannes Mente, DMD, Sabine Werner, DMD, Martin Jean Koch, MD, DMD, PhD, Volkmar Henschel, PhD, Milos Legner, PhD, Hans Joerg Staehle, MD, DMD, PhD, Shimon Friedman, DMD
This study assessed the apical leakage of ultrasonically condensed root fillings in extremely large canals, compared to cold lateral condensation and thermoplastic compaction. Ninety single-rooted teeth were used. In 45 teeth canals were enlarged to size 70 (large). The remaining 45 canals were enlarged to size 140 (extremely large). Each set of teeth was subdivided into three root-filling groups (n = 15): (1) cold lateral condensation (LC); (2) thermoplastic compaction (TC); and (3) ultrasonic lateral condensation (UC). Teeth in all six subgroups were subjected to drawing ink penetration, cleared, and evaluated for linear apical dye leakage. Significantly deeper dye penetration (p < 0.04, Wilcoxon rank-sum test) was observed for LC than for UC. TC did not differ significantly from LC and UC. Dye penetration was significantly deeper (p < 0.0001) in canals enlarged to size 140 than to size 70, independent of root-filling method. Apical leakage associated with ultrasonically condensed root fillings was less than that with cold lateral condensation. It was consistently greater in extremely large canals than that in large ones.
Efficacy of Two Contemporary Single-cone Filling Techniques in Preventing Bacterial Leakage
Francesca Monticelli, DDS, MSc, PhD, Fernanda T. Sadek, DDS, PhD, George S. Schuster, DDS, PhD, Keith R. Volkmann, DMD, PhD, Stephen W. Looney, BS, MS, PhD, Marco Ferrari, DDS, PhD, Manuel Toledano, DDS, PhD, David H. Pashley, DMD, PhD, Franklin R. Tay, BDSc(Hons), PhD
This in vitro study evaluated the sealing efficacy of three root-filling systems/techniques in preventing bacterial leakage. Instrumented single-rooted root segments were filled with (1) warm vertical compaction with gutta-percha/AH Plus; (2) single-cone technique with ActiV GP; and (3) single-cone technique with Gutta-Flow. A dual-chamber leakage model using S. mutans as a microbial marker was used for leakage evaluation. Bacterial penetration was monitored over a 100-day period. Leakage was recorded when turbidity was observed in the lower chamber. Gutta-percha warm vertical compaction exhibited the best seal with bacterial leakage observed in only 16.7% of the specimens between 59 and 100 days. All ActiV GP specimens leaked between 7 and 100 days; 50% of the Gutta-Flow specimens leaked between 22 and 100 days. The two contemporary single-cone techniques did not insure a durable apical seal against bacterial leakage. A warm vertical compaction technique using thermoplasticized gutta-percha and AH Plus sealer appears to be more effective in minimizing bacterial leakage.
Healing of a Fibrous Dysplastic Lesion in a Permanent Molar after Endodontic Therapy
Iris Slutzky-Goldberg, BSc, DMD, Ilana Heling, MSc, DMD
Fibrous dysplasia presents in two forms: monostotic and polyostotic. Both forms are more widespread among children and juveniles and may result in facial asymmetry. Neoplastic bone lesions, localized over the root apices and mimicking periapical pathosis, have been observed. Irregular pulp morphology not previously reported is described in the following case report.
A 14-year-old boy diagnosed with fibrous dysplasia was referred for endodontic treatment as the result of a necrotic pulp in an upper molar. A periapical lesion was diagnosed when the tooth was intact. After complex root canal treatment the periapical lesion healed.
Endodontic Treatment of a Mandibular Second Premolar with Four Canals Using Operating Microscope
Giorgos N. Tzanetakis, DDS, Theodoros A. Lagoudakos, DDS, MSc, Evangelos G. Kontakiotis, DDS, PhD
This clinical article presents and describes the endodontic treatment of a mandibular second premolar exhibiting a total of four separate root canals. This incidence in mandibular second premolars is particularly rare in the international endodontic literature. Only some infrequent cases of mandibular second premolars with four canals have been presented; however, this was done without the use of the operating microscope. The use of magnification is a prerequisite to locate and to confirm the exact number and position of canal orifices and to complete successfully the endodontic treatment. The endodontic treatment of the mandibular second premolar presented in this article was conducted with the aid of the operating microscope and photos of the pulp chamber floor that were taken under different steps of magnification (8×, 12.8×, and 19.1×).
Nonsurgical Endodontic Treatment of Dens Invaginatus in a Mandibular Premolar with Large Periradicular Lesion: A Case Report
Kürşat Er, DDS, PhD, Alper Kuştarcı, DDS†, Ülkü Özan, DDS†, Tamer Taşdemir, DDS, PhD
This case report describes the treatment of a dens invaginatus in a mandibular premolar with large periradicular lesion. A nonsurgical endodontic treatment was performed to tooth #28. During the treatment procedure, calcium hydroxide and a triple antibiotic paste were separately used for intracanal dressing. The apical third of the canal was obturated with mineral trioxide aggregate (MTA), and the remaining canal space was obturated with gutta-percha and AH 26 root canal sealer, using a lateral condensation technique. At follow-up examination after 1 year, the tooth was asymptomatic and radiographically showed repair of the lesion. Healing was achieved without any need for further endodontic surgical intervention.
Marginal Gingiva Discoloration by Gray MTA: A Case Report
Eduardo Antunes Bortoluzzi, MSc, Gustavo Sivieri Araújo, MSc, Juliane Maria Guerreiro Tanomaru, PhD, Mário Tanomaru-Filho, PhD
Perforation of the root canal during insertion of an intracanal post is a complication of endodontic therapy. Mineral trioxide aggregate (MTA) has been successfully used a sealer in these situations. This material has recently been formulated in white color, allowing its application in areas of esthetic concern. This is a clinical case report of a root perforation sealed with gray MTA that resulted in discoloration of the marginal gingiva. Treatment consisted of replacing gray MTA with white MTA with the aid of a dental operating microscope, producing satisfactory esthetic results.