Anesthetic Efficacy of 1.8 mL and 3.6 mL of 2% Lidocaine with 1:100,000 Epinephrine for Maxillary Infiltrations
Alan Mikesell, DDS, MS, Melissa Drum, DDS, MS, Al Reader, DDS, MS, Mike Beck, DDS, MA
The purpose of this prospective, randomized, single-blinded study was to measure the degree of anesthesia obtained with 1.8 mL and 3.6 mL of 2% lidocaine with 1:100,000 epinephrine in maxillary infiltrations. Ninety-six adult subjects randomly received infiltrations of 1.8 mL and 3.6 mL of the lidocaine solution at two separate appointments, in a crossover design. Thirty-two lateral incisors, 32 first premolars and 32 first molars were studied in this investigation. Anesthetic success (obtaining two consecutive 80 readings with the electric pulp tester) for the two volumes ranged from 97% to 100%. The onset of pulpal anesthesia was not statistically different between the two volumes. For both volumes, the lateral incisors had a higher percentage of anesthesia of short duration than the first premolar and first molar. The 3.6 mL volume provided a statistically longer duration of pulpal anesthesia for the lateral incisor, first premolar, and first molar.
Pitting Corrosion Resistance of Nickel–Titanium Rotary Instruments with Different Surface Treatments in Seventeen Percent Ethylenediaminetetraacetic Acid and Sodium Chloride Solutions
Antonio Bonaccorso, MD, Teresa Roberta Tripi, MD, PhD, Gianni Rondelli, MD, PhD, Guglielmo Guido Condorelli, MD, PhD, Giuseppe Cantatore, MD, PhD, Edgar Schäfer, MD, PhD
This study evaluated the pitting corrosion resistance of nickel-titanium (NiTi) rotary instruments with different surface treatments in 17% ethylenediaminetetraacetic acid (EDTA) and NaCl solutions. Electropolished RaCe instruments were allocated to group A, non-electropolished RaCe instruments to group B, and physical vapor deposition (PVD)–coated Alpha files to group C (10 instruments per group). Electrochemical measurements were carried out by using a potentiostat for galvanic current measurements. On the basis of electrochemical tests, no localized corrosion problems are to be expected in EDTA. In NaCl, pitting potential occurred at higher values for the electropolished and PVD instruments, indicating an increased corrosion resistance. There appears to be a risk of corrosion for NiTi instruments without surface treatments in contact with NaCl. NiTi files with PVD and electropolishing surface treatments showed an increase corrosion resistance.
Characterization of the Apical Papilla and Its Residing Stem Cells from Human Immature Permanent Teeth: A Pilot Study
Wataru Sonoyama, DDS, PhD, Yi Liu, DDS, PhD, Takayoshi Yamaza, DDS, PhD, Rocky S. Tuan, PhD, Songlin Wang, DDS, PhD, Songtao Shi, DDS, PhD, George T.-J. Huang, DDS, MSD, DSc
Mesenchymal stem cells (MSCs) have been isolated from the pulp tissue of permanent teeth (dental pulp stem cells or DPSCs) and deciduous teeth (stem cells from human exfoliated deciduous teeth). We recently discovered another type of MSCs in the apical papilla of human immature permanent teeth termed stem cells from the apical papilla (SCAP). Here, we further characterized the apical papilla tissue and stem cell properties of SCAP using histologic, immunohistochemical, and immunocytofluorescent analyses. We found that the apical papilla is distinctive to the pulp in terms of containing less cellular and vascular components than those in the pulp. Cells in the apical papilla proliferated 2- to 3-fold greater than those in the pulp in organ cultures. Both SCAP and DPSCs were as potent in osteo/dentinogenic differentiation as MSCs from bone marrows, whereas they were weaker in adipogenic potential. The immunophenotype of SCAP is similar to that of DPSCs on the osteo/dentinogenic and growth factor receptor gene profiles. Double-staining experiments showed that STRO-1 coexpressed with dentinogenic markers such as bone sialophosphoprotein, osteocalcin, and growth factors FGFR1 and TGFβRI in cultured SCAP. Additionally, SCAP express a wide variety of neurogenic markers such as nestin and neurofilament M upon stimulation with a neurogenic medium. We conclude that SCAP are similar to DPSCs but a distinct source of potent dental stem/progenitor cells. Their implications in root development and apexogenesis are discussed.
Unevenness of the Apical Constriction in Human Maxillary Central Incisors
David G. Olson, DDS, Steven Roberts, DDS, Anthony P. Joyce, DDS, D. Edward Collins, DMD, James C. McPherson III, PhD
This study examined the incisoapical extent of the apical constriction in 45 human maxillary central incisors. The null hypothesis was that the apical constriction is a flat ring. Our working hypothesis was that the constriction is actually uneven or “skewed” as it traces a path around the circumference of the canal. Teeth were split and imaged with 25× magnification, and the most apical and coronal limits of the apical constriction were identified and measured. Analysis of the data indicates that a majority (>70%) of maxillary central incisors exhibit an unevenness or “skew” of the apical constriction of greater than 100 μm in the incisoapical dimension, with a maximum measured skew of 385 μm. On the basis of the results of this study, a statistically significant (P < .05) variation in the longitudinal position of the apical constriction around its circumference was confirmed in maxillary central incisors.
Mineral Trioxide Aggregate Repair of a Perforating Internal Resorption in a Mandibular Molar
Maarten Meire, DDS, MSc, Roeland De Moor, DDS, PhD, MSc
Internal resorption is a rare condition in permanent teeth that poses difficulties for treatment. The challenge is complicated further if the resorption extends beyond the confines of the root. This article describes treatment of a perforating internal resorption in the mesial root of a second lower molar, with adjacent destruction of the alveolar bone. After cleaning the root canal space and the resorption lacuna by mechanical instrumentation, irrigation, and interim calcium hydroxide dressing, the defect was filled with mineral trioxide aggregate, and the canals were obturated conventionally with gutta percha and epoxy resin sealer. At a 2-year follow-up examination, no clinical abnormalities were found, and complete resolution of the alveolar bone lesion and establishment of a new periodontal ligament were observed.
Eugenol Inhibited the Antimicrobial Functions of Neutrophils
Dai-Chian Chen, DDS, PhD, Ya-Yun Lee, DDS, PhD, Pei-Ying Yeh, DDS, MS, Jung-Chen Lin, MS, Yu-Lin Chen, PhD, Shan-Ling Hung, PhD
Eugenol-containing restorative materials are commonly used for vital pulp therapy. A well-regulated host defense response is pivotal for the success of vital pulp therapy. The present study was to assess the effects of eugenol on the antimicrobial functions of polymorphonuclear leukocytes (neutrophils). Treatment with eugenol (≤1.25 mmol/L) for 30 minutes did not significantly affect the viability of neutrophils. However, preincubation of neutrophils with eugenol (1.25 mmol/L and 2.5 mmol/L) abolished their bactericidal activity against oral pathogens Streptococcus mutans and Actinobacillus actinomycetemcomitans. In addition, through the suppression of the extracellular release of myeloperoxidase and the intracellular production of reactive oxygen species, eugenol at sufficient concentrations impaired the activation of neutrophils by cytochalasin B and fMet-Leu-Phe (CB/fMLP). These results suggested that the antimicrobial functions of neutrophils were interfered by eugenol, and the inhibitory effects of eugenol (≤1.25 mmol/L) were not due to direct killing of neutrophils.
Radiographic Investigation of Frequency and Location of Root Canal Curvatures in Human Mandibular Anterior Incisors In Vitro
Brita Willershausen, DDS, PhD, Adrian Kasaj, DDS, Bernd Röhrig, DDS, Benjamin Briseño Marroquin, DDS, PhD
The aim of the present in vitro study was to evaluate the degree and location of root canal curvatures of mandibular anterior incisors. A total of 396 extracted human permanent anterior incisors (248 central and 148 lateral) were included in this investigation. Exclusion criteria were teeth with extensive carious lesions, restorations, and root canal treatment. The specimens were fixed in a special device and digitally x-rayed (Heliodent MD; Sirona, Benzheim, Germany; Merlin 2.1, Olympus/PerkinElmer, Waltham, MA) with the parallel technique. The distances from the cementoenamel junction (CEJ) to the first curvatures as well as the according angles were recorded. The results were analyzed descriptively, and p values were calculated with the Wilcoxon test. The mean distance between the CEJ and the first curvature of the central anterior incisors was 13.8 mm (standard deviation ± 2.6) and that of the lateral anterior incisors was 12.3 (standard deviation ± 2.5), respectively. A total of 82 (33.1%) central and a total of 118 (79.7%) lateral anterior incisors exhibited curvatures. No statistically significant differences between left and right anterior incisors could be observed regarding the canal curvature locations (p < 0.001) and the angle values (p < 0.04). The results showed a high percentage of mandibular anterior incisors with a mean curvature located 13 mm apically from the CEJ. The findings of this study may enhance the predictability of endodontic treatment and minimize errors during post insertion.
Anesthetic Efficacy of a Repeated Intraosseous Injection Following a Primary Intraosseous Injection
Joanne Jensen, DDS, MS, John Nusstein, DDS, MS, Melissa Drum, DDS, MS, Al Reader, DDS, MS†, Mike Beck, DDS, MA
The purpose of this prospective, randomized, single-blinded study was to determine the anesthetic efficacy of a repeated intraosseous injection given 30 minutes after a primary intraosseous injection. Using a crossover design, 55 subjects randomly received a primary X-tip intraosseous injection (Dentsply Inc, York, PA) of 1.4 mL of 2% lidocaine with epinephrine (using the Wand; Milestone Scientific, Deerfield, IL) and a repeated intraosseous or mock injection at 30 minutes in two appointments. The first molar and adjacent teeth were pulp tested every 2 minutes for a total of 120 minutes. Success was defined as obtaining two consecutive 80 readings with the electric pulp tester. Success of the initial intraosseous injection was 100% for the first molar. The repeated intraosseous injection mimicked the initial intraosseous injection in terms of pulpal anesthesia and statistically provided another 15 minutes of pulpal anesthesia. In conclusion, using the methodology presented, repeating the intraosseous injection 30 minutes after an initial intraosseous injection will provide an additional 15 minutes of pulpal anesthesia.
Immunohistochemical Localization of LIM Mineralization Protein 1 in Pulp–Dentin Complex of Human Teeth with Normal and Pathologic Conditions
Xiaoying Wang, DDS, PhD1, Qi Zhang, DDS, PhD, Zhi Chen, DDS, PhD, Lu Zhang, DDS, PhD
LIM mineralization protein 1 (LMP-1) is an essential positive regulator of osteoblast differentiation and maturation and bone formation. However, the expression and distribution of LMP-1 in human teeth are largely unknown. The aim of this study was to detect the expression of LMP-1 in normal healthy human teeth and human teeth with various pathologic conditions. LMP-1 expression was determined by immunohistochemistry in all of the samples including 12 healthy teeth, 10 teeth with caries, 12 teeth with pulpitis, and 4 teeth with pulp calcification. We found that LMP-1 was expressed primarily in predentin, odontoblasts, and endothelial cells of the blood vessels of healthy teeth. In addition, LMP-1 expression was also found in unmineralized reparative dentin, odontoblast-like cells, and pulp fibroblasts in teeth with caries and pulpitis. Furthermore, we found LMP-1 expression on the surface of the pulp stone or in the residual predentin of teeth with pulp calcification. Our data suggest that LMP-1 plays a role in odontoblast differentiation and dentin matrix mineralization of human teeth with normal and pathologic conditions.
Evaluation of the Interaction between Sodium Hypochlorite and Chlorhexidine Gluconate and its Effect on Root Dentin
Tung B. Bui, DDS, J. Craig Baumgartner, DDS, PhD, John C. Mitchell, PhD
The combination of sodium hypochlorite (NaOCl) and chlorhexidine (CHX) forms a precipitate. The aim of this study was to evaluate the effect of irrigating root canals with a combination of NaOCl and CHX on root dentin and dentinal tubules by using the environmental scanning electron microscope (ESEM) and a computer program (Photoshop CS2). Forty-four extracted single-rooted human teeth were instrumented and irrigated with both NaOCl and CHX to produce a precipitate. Root canal surfaces were analyzed with the ESEM. The amount of remaining debris and number of patent tubules were determined. There were no significant differences in remaining debris between the negative control group and the experimental groups. There were significantly fewer patent tubules in the experimental groups when compared with the negative control group. The NaOCl/CHX precipitate tends to occlude the dentinal tubules. Until this precipitate is studied further, caution should be exercised when irrigating with NaOCl and CHX.
Identification of a C-shaped Canal System in Mandibular Second Molars—Part II: The Effect of Bone Image Superimposition and Intraradicular Contrast Medium on Radiograph Interpretation
Bing Fan, DDS, MSc, PhD, Yuan Gao, DDS, MSc, PhD, Wei Fan, DDS, MSc, PhD, James L. Gutmann, DDS, PhD, FACD, FICD, FADI
The purpose of this study was to investigate the effect of image superimposition from surrounding alveolar bone and intraradicular contrast medium on radiographic interpretation of a C-shaped canal system in mandibular second molars. Thirty mandibular second molars with fused roots were collected and stored in 10% formalin solution. After being scanned by microcomputed tomography and reconstructed, the buccal-lingual radiographs of each tooth were taken with or without intraradicular contrast medium and mandibular bony plates. The number of mesial and distal canals in the coronal-to-middle canal portion and the canal number in the apical 4-mm area were recorded. The buccal-lingual and three-dimensional view of reconstructed canal images were used to evaluate the accuracy of radiograph reading. The results were subjected to the Friedman and chi-square test. The results showed that without intraradicular contrast medium, the bone superimposition could decrease the accuracy of canal recognition significantly (p < 0.001), especially in the apical area. When contrast medium was in canals, the canal reading seemed not to be affected by the bone superimposition (p > 0.05). Based on these findings, the intraradicular contrast medium could increase the accuracy of canal recognition of a C-shaped canal system in mandibular second molars despite the bone image superimposition, especially in the detection of continuous C-shaped canals and the canals in the apical area.
Ameloblastoma Suggesting Large Apical Periodontitis
Luiz Augusto Faitaroni, DDS, Mike Reis Bueno, DDS, MSc, Artur Aburad De Carvalhosa, DDS, MSc, PhD, Karin Astrid Bruehmueller Ale, DDS, Carlos Estrela, DDS, MSc, PhD
This case report describes the endodontic treatment of a large apical periodontitis with well-defined margins adjacent to teeth #22–24. After the initial endodontic treatment, continued expansion of the mandible cortical bone was observed, indicating a need to surgically enucleate the lesion and submit it for histopathologic examination. The microscopic examination indicated a diagnosis of ameloblastoma. Ameloblastoma is a benign epithelial neoplasm of odontogenic origin, and depending on the stage of development, it can mimic a periapical lesion and therefore should be considered in establishing an endodontic differential diagnosis. The definitive diagnosis for some periapical lesions can only be made by a histopathologic examination.
Interleukin-8 Is Increased in Gingival Crevicular Fluid from Patients with Acute Pulpitis
Virginia Karapanou, DMD, MS, Duraisamy Kempuraj, PhD, Theoharis C. Theoharides, PhD, MD
Irreversibly inflamed pulp (IIP) constitutes both a pathophysiologic and a diagnostic challenge. Gingival crevicular fluid (GCF) samples were obtained with Periopaper strips from IIP and adjacent and contralateral teeth for interleukin-8 (CXCL8) and tumor necrosis factor–alpha (TNF-α) measurements. Pain intensity was reported by using a verbal numeric scale (1–10). TNF-α (n = 25) was not detectable in GCF, whereas CXCL8 (n = 17) was significantly greater in IIP (302.1 ± 164.9 pg/mL) compared with adjacent (139 ± 138.58 pg/mL; P = .0072) or contralateral (173.8 ± 166.4 pg/mL; P = .0231) teeth. A subgroup of high pain (>5) patients (n = 7) had CXCL8 IIP levels (323.6 ± 148.4 pg/mL) that were significantly different from the contralateral teeth (P = .0262); however, they did not differ from the adjacent teeth (P = .1649), suggesting that neighboring teeth might also have inflammation. Another group of patients (n = 7) who had received local anesthesia before sampling had very low IIP CXCL8 levels. GCF CXCL8 levels might be a useful measurement for staging patients with acute pulpitis.
The Evaluation of Root Canal Morphology of the Mandibular First Molar in an Indian Population Using Spiral Computed Tomography Scan: An In Vitro Study
Joseph Reuben, BDS, Natanasabapathy Velmurugan, MDS, Deivanayagam Kandaswamy, MDS
In this study, root canal morphology of 125 extracted mandibular first molars from an Indian population was evaluated by using spiral computed tomography (SCT). The results of this study showed that the majority of the teeth samples (84.48%) had the 3 canal (mesiobuccal, mesiolingual, and 1 distal canal) configuration and that the cementoenamel junction coincided with the roof of the pulp chamber in 37.09% of the samples only.
Sealing Ability of a New Polydimethylsiloxane-based Root Canal Filling Material
Ahmet R. Özok, PhD, Lucas W.M. van der Sluis, PhD, Min-Kai Wu, PhD, Paul R. Wesselink, PhD
We tested the null hypothesis that there is no difference in the sealing ability of GuttaFlow, RoekoSeal, and AH26 in root canals. Sixty extracted mandibular premolars were filled with AH26 (lateral compaction), RoekoSeal, or GuttaFlow (modified single-cone). The sealing ability of the root canal fillings was measured weekly (4 weeks) by using a glucose penetration model. Kruskal-Wallis test revealed significant differences in glucose penetration between the experimental groups at weeks 1, 2, 3, and 4. Whereas GuttaFlow showed the highest amount of leakage at all times, AH26 showed the lowest. There was no significant difference between RoekoSeal-filled and AH26-filled root canals throughout the experimental period. AH26 showed better sealing ability in root canals than GuttaFlow.
Cutting Efficiency of Five Different Types of Rotary Nickel–Titanium Instruments
Edgar Schäfer, Prof Dr, Mirjam Oitzinger, DDS
The purpose of this study was to compare the cutting efficiency of the following rotary nickel-titanium instruments: Alpha-File (Komet, Lemgo, Germany), FlexMaster (VDW, Munich, Germany), Mtwo (VDW, Munich, Germany), ProFile (Dentsply Maillefer, Ballaigues, Switzerland), and RaCe (FKG, La-Chaux-de-Fonds, Switzerland). New .06/25 and .04/35 instruments were used; sample size was 12 for each group. Cutting efficiency of all 120 instruments was determined in a rotary working motion by means of a computer-driven testing device. Special plastic samples with a cylindrical canal were used, and the maximum penetration depth of the instruments into the lumen was the criterion for cutting efficiency. Statistical analysis was performed by using analysis of variance and post hoc Student-Newman-Keuls test. Out of all .06/25 instruments, Mtwo and RaCe displayed significantly greater penetration depths than all other instruments, whereas for the other size FlexMaster, Mtwo, and RaCe were significantly superior to all other instruments (p < 0.05). For both sizes, the significantly lowest values were obtained by ProFile (p < 0.05). Under the condition of this study, Mtwo and RaCe displayed the greatest cutting efficiency.
Antimicrobial Effects of Photodynamic Therapy on Patients with Necrotic Pulps and Periapical Lesion
Aguinaldo Silva Garcez, MSc, Silvia Cristina Nuñez, PhD⁎, Michael R. Hamblin, PhD, Martha Simões Ribeiro, PhD
This study analyzed the antimicrobial effect of photodynamic therapy (PDT) in association with endodontic treatment. Twenty patients were selected. Microbiological samples were taken after accessing the canal, endodontic therapy, and PDT. At the end of the first session, the root canal was filled with Ca(OH)2, and after 1 week, a second session of the therapies was performed. Endodontic therapy gave a mean reduction of 1.08 log. The combination with PDT significantly enhanced the reduction (1.83 log, p = 0.00002). The second endodontic session gave a similar diminution to the first (1.14 log), and the second PDT was significantly more effective than the first (p = 0.002). The second total reduction was significantly higher than the second endodontic therapy (p = 0.0000005). The total first + second reduction (3.19 log) was significantly different from the first combination (p = 0.00006). Results suggest that the use of PDT added to endodontic treatment leads to an enhanced decrease of bacterial load and may be an appropriate approach for the treatment of oral infections.
Sealing Properties of Different Obturation Systems Applied over Apically Fractured Rotary Nickel–Titanium Files
Emre Altundasar, DDS, PhD, Cem Sahin, DDS, Bahar Ozcelik, DDS, PhD, Zafer C. Cehreli, DDS, PhD
This study investigated the sealing properties of cold laterally compacted gutta percha and Thermafil applied over different apically fractured rotary nickel-titanium files. Extracted human premolars were prepared by using ProTaper (Dentsply-Maillefer, Ballaigues, Switzerland) or ProFile (Dentsply-Maillefer) systems (n = 40 for each), after which half of the specimens in each subgroup were subjected to instrument separation at the apical level. For each rotary system, roots with and without apically separated instruments (n = 10 for each) were filled with the two obturation systems and the levels of fluid conductance were recorded. In the absence of instrument separation, the leakage of Thermafil (Dentsply Maillefer) was significantly less than that achieved with cold lateral compaction (p < 0.05), whereas Thermafil yielded similar amounts of leakage in roots prepared with the ProTaper and ProFile systems (p < 0.05). Roots with fractured ProTaper instruments displayed significantly less leakage than those filled without ProTaper fragments, regardless of the obturation technique used (p < 0.05). However, intracanal separation of ProFile instruments increased the leakage (p < 0.05), but the obturation method did not influence fluid conduction (p > 0.05). These results reveal the variability of leakage associated with apically fractured ProFile and ProTaper files and different obturation methods used.
Treatment Outcome in Endodontics: The Toronto Study—Phases 3 and 4: Orthograde Retreatment
Cristian de Chevigny, DMD, MSc, Thuan T. Dao, DMD, MSc, PhD, Bettina R. Basrani, DDS, PhD, Vincent Marquis, DMD, MSc, Mahsa Farzaneh, DDS, MSc, Sarah Abitbol, DDS, MSc, Shimon Friedman, DMD
Outcome 4–6 years after retreatment was assessed for Phases 3 and 4 of the Toronto Study. Of 477 teeth retreated, 333 were lost to follow-up, 18 were extracted, and 126 (41% recall, excluding 124 discontinuers) were examined for outcome of healed (periapical index score, ≤2; no signs or symptoms) or diseased. When pooled with Phases 1 and 2, 187 of 229 teeth (82%) were healed. Logistic regression identified significant (P ≤ .05) preoperative outcome predictors: root filling quality (odds ratio [OR], 4.18; confidence interval [CI], 1.72–10.12; healed: inadequate, 88%; adequate, 66%), perforation (OR, 4.01; CI, 1.28–12.62; healed: absent, 87%; present, 56%), and radiolucency (OR, 3.33; CI, 1.19–9.36; healed: absent, 93%; present, 80%). In teeth with radiolucency, outcome predictors were number of treatment sessions (OR, 12.08; CI, 1.84–∞; healed: one, 100%; ≥2, 77%) and previous root filling quality (OR, 7.68; CI, 2.36–26.89; healed: inadequate, 86%; adequate, 50%). Outcome was better in teeth with inadequate previous root filling, without perforation and radiolucency. Suggested significance of number of treatment sessions in teeth with radiolucency requires validation from randomized controlled trials.
Effect of Electropolishing ProFile Nickel–Titanium Rotary Instruments on Cyclic Fatigue Resistance, Torsional Resistance, and Cutting Efficiency
Tung B. Bui, DDS, John C. Mitchell, PhD, J. Craig Baumgartner, DDS, PhD
This study investigated the effect of electropolishing ProFile nickel titanium rotary instruments on torque resistance, fatigue resistance, and cutting efficiency. Size 25/.04 ProFile files (Dentsply Maillefer, Switzerland) that were nonpolished for the control group (n = 15) and electropolished for the experimental group (n = 15) were used for each experiment. Cyclical fatigue was determined by counting rotations until breakage with an applied 30°, 45°, and 60° curve with a 5-mm radius. Torque and angle at failure were measured by rotating clamped files at 2 rpm until breakage. Cutting efficiency was determined by measuring the velocity of file advancement into plastic blocks with 100-g constant force for 5 seconds. Data were analyzed by either an unpaired t test or analysis of variance followed by a Fisher probable least-square difference test. Electropolishing significantly reduced resistance to cyclic fatigue but did not affect torsional resistance. However, electropolishing reduced the angle at failure and amount of unwinding. Electropolishing did not significantly affect cutting efficiency.
Mineral Trioxide Aggregate with or without Calcium Chloride in Pulpotomy
Eduardo Antunes Bortoluzzi, DDS, MS, PhD, Norberto Juárez Broon, DDS, MS, Clovis Monteiro Bramante, DDS, MS, PhD, Alberto Consolaro, DDS, MS, PhD, Roberto Brandão Garcia, DDS, MS, PhD, Ivaldo Gomes de Moraes, DDS, MS, PhD, Norberti Bernadineli, DDS, MS, PhD
The aim of this study was to evaluate the reaction of the pulp tissue against mineral trioxide aggregate (MTA) with or without 10% calcium chloride (CaCl2). Pulpotomies were performed in 4 canines and 8 premolars of two 8-month-old dogs. MTA with or without CaCl2 was applied on the pulp tissue. The animals were killed after 90 days, and the specimens were processed for the microscopic analysis. Pulp tissue response was similar for MTA with and without CaCl2. Pulp vitality was present in all specimens, along with pulp repair with formation of mineralized tissue bridging. The addition of CaCl2 to MTA did not change its biologic properties in formation of mineralized barrier after pulpotomy.
A Mandibular Third Molar with Three Mesial Roots: A Case Report
Gianluca Plotino, DDS
Although its most common configuration is 2 roots and 3 root canals, mandibular molars might have many different combinations. A case of unusual root canal morphology is presented to demonstrate anatomic variations in mandibular molars. Endodontic therapy was performed in a mandibular third molar with 3 separate mesial roots. The appearance of the pulp chamber floor revealed 4 separate canal orifices. Radiographically the 4 root canals ended in their own distinct foramen. Many reports deal with 3 orifices or 3 independent canals in the mesial root, but none described 3 mesial canals in 3 separate mesial roots, indicating a rare anatomic configuration. This report points out the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise might have ended in failure.
Coronal Microleakage of Two Root-end Filling Materials Using a Polymicrobial Marker
Suzana Ferk Luketić, DDS, Ana Malčić, DDS, Silvana Jukić, DDS, PhD, Ivica Anić, DDS, PhD, Sanja Šegović, DDS, PhD, Smilja Kalenić, MDS, PhD
The purpose of this study was to evaluate polymicrobial coronal leakage of mineral trioxide aggregate (MTA) and amalgam. There were 108 single-rooted teeth randomly divided into 3 groups of 32 teeth each and positive and negative control groups of 6 teeth and obturated with gutta percha and either Diaket (3M/ESPE, Seefeld, Germany), AH Plus (Dentsply, De Trey, Konstanz, Germany), or Ketac Endo (3M/ESPE). These groups were further divided into 2 subgroups of 16 teeth in which root ends were resected and obturated with either MTA or zinc-free amalgam. The samples have been incorporated in a dual-chamber leakage model with a polymicrobial marker of five facultative anaerobes on the coronal part. Leakage was observing during a period of 90 days. The least leakage was found in a combination of Diaket and MTA (76.9 ±14.8 days) followed by AH Plus and MTA (66.1 ± 18.7), Diaket and amalgam (60.0 ± 23.1), AH Plus and amalgam (56.9 ± 22.1), and Ketac Endo and MTA (42.1 ± 17.8), whereas the greatest leakage was observed in the Ketac Endo and amalgam group (40.0 ± 17.24). Samples filled with MTA showed significantly better sealing than samples filled with amalgam (p < 0.05).
An In Vitro Evaluation of the Growth of Human Periodontal Ligament Fibroblasts after Exposure to a Methacrylate-based Endodontic Sealer
Erich P. Heitman, DMD, Anthony P. Joyce, DDS, James C. McPherson III, PhD, Steven Roberts, DDS, Augustine Chuang, PhD
The cytotoxicity of Epiphany root canal sealer at various concentrations from 25–800 μg/mL on human periodontal ligament (HPDL) fibroblasts was evaluated at 1, 3, and 7 days. Controls included untreated cells and cells treated with the vehicle for Epiphany suspension. Fibroblast viability was assessed by 2 methods, crystal violet staining in 24-well plates and the fluorescence-based CyQUANT Cell Proliferation Assay in 96-well plates. Significant cytotoxicity against HPDL fibroblast growth by Epiphany was both time- and concentration-dependent. On day 1, 800 μg/mL, the highest concentration of Epiphany, showed significant cytotoxicity (P ≤ .001). By day 7, all concentrations greater than 25 μg/mL showed significant (P ≤ .05) loss of viability. This study demonstrated increased Epiphany cytotoxicity with an increase in concentration or exposure time.