Multiple Autoclave Cycles Affect the Surface of Rotary Nickel-Titanium Files: An Atomic Force Microscopy Study
Caroline R.A. Valois, DDS, MsC, PhD, Luciano P. Silva, DDS, PhD, Ricardo B. Azevedo, DDS, MsC, PhD
The purpose of this study was to evaluate the surface of rotary nickel-titanium (Ni-Ti) files after multiple autoclave cycles. Two different types of rotary Ni-Ti (Greater Taper and ProFile) were attached to a glass base. After 1, 5, and 10 autoclave cycles the files were positioned in the atomic force microscope. The analyses were performed on 15 different points. The same files were used as control before any autoclave cycle. The following vertical topographic parameters were measured: arithmetic mean roughness, maximum height, and root mean square. The differences were tested by analysis of variance with Tukey test. All topographic parameters were higher for both Greater Taper and ProFile after 10 cycles compared with the control (P < .05). ProFile also showed higher topographic parameters after 5 cycles compared with the control (P < .05). The results indicated that multiple autoclave cycles increase the depth of surface irregularities located on rotary Ni-Ti files.
Effect of Unintentionally Extruded Calcium Hydroxide Paste Including Barium Sulfate as a Radiopaquing Agent in Treatment of Teeth with Periapical Lesions: Report of a Case
Hasan Orucoglu, DDS, PhD, Funda Kont Cobankara, DDS, PhD
Calcium hydroxide [Ca(OH)2] has been widely used as short- or long-term intracanal antibacterial dressing material after endodontic treatment. In general when used in endodontics, Ca(OH)2 paste is composed of the powder, a vehicle, and a radiopacifier. To provide radiopacity, barium sulfate (BaSO4) powder is usually added to the paste. In this case report, BaSO4:Ca(OH)2 powders (ratio 1:8) and distilled water were mixed and applied as dressing material after root canals of mandibular left canine and premolar teeth with periapical lesions. However, the prepared paste was unintentionally extruded into the periapical lesion during application. The patient was seen 12 and 36 months later, at which point periapical healing was evaluated. At this time, it was observed that the periapical lesion had disappeared, but white radiopaque spots were seen at the place where calcium hydroxide remnants had originally been present. The presented case report reveals that when Ca(OH)2 paste that included BaSO4 was applied as an intracanal dressing and extruded through the periapical lesion associated with pulpless teeth, it had no detrimental effect. However, healing might take longer when Ca(OH)2 paste including BaSO4 is used, so deliberate overextension is not advocated.
A Retrospective Study Comparing Clinical Outcomes after Obturation with Resilon/Epiphany or Gutta-Percha/Kerr Sealer
Taylor P. Cotton, DDS, William G. Schindler, DDS, MS, Scott A. Schwartz, DDS, William R. Watson, DDS, MS, Kenneth M. Hargreaves, DDS, PhD
The purpose of this retrospective study was to evaluate the treatment outcome of root canal systems obturated with gutta-percha and Kerr Pulp Canal Sealer compared with Resilon and Epiphany sealer. One hundred three teeth treated in a private endodontic practice were included in the study. Clinical outcomes (healed versus nonhealed) were assessed by using the Periapical Index determination and clinical evaluation at recall appointments. The magnitude of the association between obturation materials used and outcome measured was evaluated with univariate and multivariate logistic regression analysis. Univariate analysis indicated that pulpal vitality, presence of a preoperative lesion, and length of recall times were statistically significant in predicting the outcome. Logistic regression analysis showed that age, tooth position, and length of recall times were statistically significant in predicting the outcome. Root canal systems obturated with gutta-percha and Kerr Pulp Canal Sealer or Resilon and Epiphany sealer had statistically indistinguishable differences in clinical outcome.
Effect of 2% Chlorhexidine Gel Mixed with Calcium Hydroxide as an Intracanal Medication on Sealing Ability of Permanent Root Canal Filling: A 6-month Follow-up
Evangelos G. Kontakiotis, DDS, PhD, Ioannis N. Tsatsoulis, DDS, Styliani I. Papanakou, DDS, Giorgos N. Tzanetakis, MSc, DDS
The present study was conducted to determine the influence of 2 intracanal medicaments (calcium hydroxide, chlorhexidine gel 2%) when used either alone or combined on the short- and long-term sealing ability of permanent root canal fillings. Ninety human upper central incisors were divided into 4 experimental groups (n=20). All root canals were instrumented in a step-back motion and then treated as follows: group I, root canal dressing with calcium hydroxide for 2 weeks and then obturation with laterally compacted gutta-percha and AH26 sealer; group II, chlorhexidine gel 2% for 2 weeks and obturation as in group I; group III, dressing with a new paste made by mixing calcium hydroxide plus chlorhexidine gel 2% for 2 weeks and obturation as described previously; group IV, immediately obturated with laterally compacted gutta-percha and AH26 sealer. Leakage along root canal fillings was measured using the transport fluid model. Short term measurements were carried out for 3 hours after 24 hours equilibrium establishment. Leakage was measured again at 6 months after the initial measurement. At 3 hours, no significant differences were found among the 4 experimental groups. Long-term measurements showed that also at 6 months no significant differences were observed between the group IV and the other 3 experimental groups. Under the conditions of the present study, it could be supported that none of the medications used seemed to affect negatively neither the short- nor the long-term sealing ability of the tested obturation technique. On the basis of these results and because of its increased antimicrobial action as it is supported in the literature, the new paste made of calcium hydroxide plus chlorhexidine gel 2% can be proposed for use in clinical practice without affecting the sealing ability of root canal obturation.
Fluid Flow Evaluation of Fuji Triage and Gray and White ProRoot Mineral Trioxide Aggregate Intraorifice Barriers
Anthony D. John, DDS, MS, Terry D. Webb, DDS, MS, Glen Imamura, DDS, MS, Gary G. Goodell, DDS, MS, MA
The purpose of this study was to compare coronal leakage in teeth with 2-mm intraorifice barriers of Fuji Triage glass ionomer, gray mineral trioxide aggregate (MTA), and white MTA using a fluid flow model. Forty anterior teeth were decoronated, instrumented, and obturated. Teeth were divided into positive and negative controls and 3 experimental groups receiving 2-mm barriers of Fuji Triage glass ionomer, gray MTA, or white MTA. Fluid movement was tested 3 times for each tooth, and means were calculated. Data were analyzed with one-way analysis of variance and Student-Newman-Keuls (α = .05). Fluid movement means and standard deviations were as follows: Fuji Triage, 0.47 ± 0.45 mm; gray MTA, 0.49 ± 0.44 mm; white MTA, 0.52 ± 0.23 mm; and positive controls, 3.57 ± 1.13 mm. No significant differences were found among the experimental groups. However, positive controls leaked significantly more than all experimental groups at P <.001.
A Comparison Study of Periapical Repair in Dogs' Teeth Using RoekoSeal and AH Plus Root Canal Sealers: A Histopathological Evaluation
Mário Roberto Leonardo, DDS, MS, PhD⁎, Daniel Silva Herzog Flores, DDS, MS, Francisco Wanderley Garcia de Paula e Silva, DDS, MS, Renato de Toledo Leonardo, DDS, MS, PhD, Léa Assed Bezerra da Silva, DDS, MS, PhD
The objective of the study was to evaluate the biocompatibility of RoekoSeal sealer Roeko (Dental Products, Langenau, Germany) with the periapical tissues of dogs and compare it with AH Plus sealer (Dentsply/De Trey, Konstanz, Germany). The pulps of 32 root canals were removed, the apical cementum layer perforated, the biomechanical preparation performed, and the root canals filled by lateral condensation technique. Ninety days after the surgery, the animals were euthanized, the bone with teeth removed, and the samples prepared for histopathological analysis. In group 1 (RoekoSeal Automix), deposition of mineralized tissue was observed, with complete newly mineralized apical formed tissue in 43.8% and partial sealing in 56.2%. In group 2 (AH Plus), in 12.5% there was complete newly mineralized apical formed tissue, in 75% the sealing was partial, and in 12.5% there was no sealing (p < 0.05). There were no differences between the groups in relation to the inflammatory infiltrate; thickness of the periodontal ligament; and the resorption of dentin, cementum or bone (p > 0.05).
Changes in the Homeostatic Mechanism of Dental Pulp with Age: Expression of the Core-binding Factor Alpha-1, Dentin Sialoprotein, Vascular Endothelial Growth Factor, and Heat Shock Protein 27 Messenger RNAs
Kenichi Matsuzaka, DDS, PhD, Takashi Muramatsu, DDS, PhD, Akira Katakura, DDS, PhD, Kazuyuki Ishihara, DDS, PhD, Sadamitsu Hashimoto, DDS, PhD, Masao Yoshinari, PhD, Takayuki Endo, DDS, PhD, Masakazu Tazaki, DDS, PhD, Masuro Shintani, DDS, PhD, Yutaka Sato, DDS, PhD, Takashi Inoue, DDS, PhD
Dental pulp has various characteristics in the pulp chamber, but only a few biological evaluations about the effect of age on dental pulp tissue have been reported. The purpose of this study was to compare dental pulp from young and adult rats to characterize the homeostatic mechanism. Dental pulp cells (DPCs) were obtained from the first molar of rats, weighing 150 g each for the young group and 350 g each for the adult group. The expression of core-binding factor alpha-1 (Cbfa-1), vascular endothelial growth factor (VEGF), or heat shock protein (HSP) 27 messenger RNAs (mRNAs) by cultured pulp cells was determined by using a quantitative real-time PCR system after 3, 7, or 14 days. The expression of Cbfa-1 mRNA in the young group was higher than in the adult group. Expression of VEGF and HSP27 mRNAs in the adult group was higher than in the young group. The self-defense system in young DPCs is undertaken by calcification, but in adult DPCs it is carried out by the expression of self-defense proteins and the regeneration of vessels.
Resistance of a 4-META–Containing, Methacrylate-based Sealer to Dislocation in Root Canals
Matthew S. Lawson, DMD, Bethany Loushine, BS, Sui Mai, DDS, R. Norman Weller, DMD, MS, David H. Pashley, DMD, PhD, Franklin R. Tay, BDSc (Hons), PhD, Robert J. Loushine, DDS
The dislocation resistance of root fillings created with MetaSEAL, a self-adhesive 4-META–containing methacrylate resin-based sealer, was evaluated. Forty-six incisors were cleaned and shaped using NaOCl and EDTA as irrigants. They were filled with gutta-percha/MetaSEAL or gutta-percha/AH Plus sealer using either a single-cone technique or warm vertical compaction (n = 10). The roots were sectioned at the coronal and middle thirds to obtain thin slices, which were subjected to compressive loading to displace the set sealer/filling toward the coronal side of the slice. The remaining six teeth were filled with gutta-percha/MetaSEAL and cryofractured for scanning electron microscopic examination. The push-out strength of AH Plus was significantly higher than MetaSEAL irrespective of filling techniques (p < 0.05). A minimal hybrid layer was seen in radicular dentin, and resin tags were inconsistently identified from canal walls in the MetaSEAL-filled canals. The lower dislocation resistance in MetaSEAL-filled canals challenges the use of a self-adhesive bonding mechanism to create continuous bonds inside root canals.
A Novel Approach in Assessment of Coronal Leakage of Intraorifice Barriers: A Saliva Leakage and Micro-computed Tomographic Evaluation
Parisa Zakizadeh, DDS, MS, Sally J. Marshall, PhD, Charles I. Hoover, PhD, Ove A. Peters, DMD, MS, PhD, W. Craig Noblett, DDS, MS, Stuart A. Gansky, DrPH, Harold E. Goodis, DDS
The efficacy of amalgam, Fuji-Plus, Geristore, and mineral trioxide aggregate (MTA) as intraorifice barriers was compared in a simulated saliva leakage model. Fifty teeth were divided into 4 experimental (n = 10 each) and 2 control groups (n = 5 each). Two millimeters of the materials was placed as intraorifice barriers and brought into contact with human saliva in a coronal reservoir. Bacterial leakage into the apical reservoir was assessed daily for 3 months. Geristore barriers leaked significantly more often (5/10) than Fuji-Plus (0/10, P < .05) at 60 days. The first Fuji-Plus sample leaked after 70 days; after 90 days, 3 (Fuji-Plus), 4 (MTA, amalgam), and 6 (Geristore) samples leaked. There were no significant differences between the experimental groups at that time point.
Three-dimensional gap volumes in the barrier-dentin interface and the porosity of the barrier materials were compared by using micro–computed tomography (μCT). A measurable gap was evident in only 1 specimen with an MTA barrier. MTA was significantly less porous than Fuji-Plus and Geristore (P ≤ .05), whereas amalgam was too radiopaque to allow μCT measurements.
In conclusion, Fuji-Plus might be an effective intraorifice barrier (up to 70 days in vitro), but all 4 materials showed leakage in some specimens at 90 days.
In Vitro Fracture Resistance and Deflection of Pulpless Teeth Restored with Fiber Posts and Prepared for Veneers
Camillo D'Arcangelo, DDS, Francesco De Angelis, DDS, Mirco Vadini, DDS, Simone Zazzeroni, DDS, Christian Ciampoli, DDS, Maurizio D'Amario, DDS
The aim of this in vitro study was to evaluate the influence of endodontic therapy, veneer preparation, and their association on fracture resistance and deflection of pulpless anterior teeth and assess whether restoration with quartz fiber-reinforced post can influence these properties. Seventy-five freshly extracted human maxillary central incisors were selected. Teeth were randomly divided into 4 experimental groups (veneer preparation/endodontic therapy/endodontic therapy and veneer preparation/endodontic therapy, veneer preparation, and fiber post placement) and a control group (n = 15). Specimens were loaded to fracture recording crown deflection under load, and data were statistically analyzed. Veneer preparations and endodontic treatment did not significantly influence fracture resistance of maxillary incisors. On the contrary, preparation for veneer significantly increased the deflection values of the specimens. Fiber post restorations seemed to significantly increase mean maximum load values for specimens prepared for veneers. A fiber-reinforced post restoration can be suggested when endodontic treatment is associated with veneer preparation.
Neuropeptides in Dental Pulp: The Silent Protagonists
Javier Caviedes-Bucheli, DDS, MSc, Hugo Roberto Muñoz, DDS, MSc, María Mercedes Azuero-Holguín, DDS, Esteban Ulate, DDS
Dental pulp is a soft mesenchymal tissue densely innervated by afferent (sensory) fibers, sympathetic fibers, and parasympathetic fibers. This complexity in pulp innervation has motivated numerous investigations regarding how these 3 major neuronal systems regulate pulp physiology and pathology. Most of this research is focused on neuropeptides and their role in regulating pulpal blood flow and the development of neurogenic inflammation. These neuropeptides include substance P, calcitonin gene-related peptide, neurokinin A, neuropeptide Y, and vasoactive intestinal polypeptide among others. The purpose of this article is to review recent advances in neuropeptide research on dental pulp, including their role in pulp physiology, their release in response to common dental procedures, and their plasticity in response to extensive pulp and dentin injuries. Special attention will be given to neuropeptide interactions with pulp and immune cells via receptors, including studies regarding receptor identification, characterization, mechanisms of action, and their effects in the development of neurogenic inflammation leading to pulp necrosis. Their role in the growth and expansion of periapical lesions will also be discussed. Because centrally released neuropeptides are involved in the development of dental pain, the pain mechanisms of the pulpodentin complex and the effectiveness of present and future pharmacologic therapies for the control of dental pain will be reviewed, including receptor antagonists currently under research. Finally, potential clinical therapies will be proposed, particularly aimed to manipulate neuropeptide expression or blocking their receptors, to modulate a variety of biologic mechanisms, which preliminary results have shown optimistic results.
Seven-year Clinical Evaluation of Painful Cracked Teeth Restored with a Direct Composite Restoration
Niek J.M. Opdam, DDS, PhD, Joost J.M. Roeters, DDS, PhD, Bas A.C. Loomans, DDS, PhD, Ewald M. Bronkhorst, MSc, PhD
The purpose of this study was to investigate long-term clinical effectiveness of treating painful cracked teeth with a direct bonded composite resin restoration. The hypothesis tested was that cracked teeth treated with or without cuspal coverage showed the same performance. Forty-one patients attended a dental practice with a painful cracked tooth that was restored with a direct composite resin restoration. Twenty teeth were restored without and 21 with cuspal coverage. After 7 years, 40 teeth could be evaluated. Three teeth without cuspal coverage needed an endodontic treatment, of which 2 failed as a result of fracture. No significant differences were found for tooth or pulp survival. Three more repairable restoration failures were recorded. Mean annual failure rate of restorations without cuspal coverage was 6%; no failures in restorations with cuspal coverage occurred (P = .009). A direct bonded composite resin restoration can be a successful treatment for a cracked tooth.
Extension and Density of Root Fillings and Postoperative Apical Radiolucencies in the Veterans Affairs Dental Longitudinal Study
Yan Zhong, DMD, PhD, Joel Chasen, DMD, Ryan Yamanaka, DDS, Raul Garcia, DMD, MMS, Elizabeth Krall Kaye, PhD, MPH, Jay S. Kaufman, PhD, Jianwen Cai, PhD, Tim Wilcosky, PhD, Martin Trope, DMD, Daniel J. Caplan, DDS, PhD
We evaluated the association between radiographically assessed extension and density of root canal fillings and postoperative apical radiolucencies (ARs) by using data from 288 participants in the Veterans Affairs Dental Longitudinal Study. Study subjects were not Veterans Affairs patients; all received their medical and dental care in the private sector. Generalized estimating equations were used to account for multiple teeth within subjects and to control for covariates of interest. Defective root filling density was associated with increased odds of postoperative AR among teeth with no preoperative AR (odds ratio, 3.0; 95% confidence interval [CI], 1.3–7.1), although preoperative AR was the strongest risk factor for postoperative AR (odds ratio, 29.2; 95% CI, 13.6–63.0 among teeth with ideal density). Compared with well-extended root fillings, neither overextended nor underextended root fillings separately were related to postoperative AR, but when those 2 categories were collapsed into one poorly extended category, poor extension was related to postoperative AR (odds ratio, 1.8; 95% CI, 1.1–3.2).
Influence of Irrigation Regimens on the Adherence of Enterococcus faecalis to Root Canal Dentin
Anil Kishen, BDS, MDS, PhD, Chee-Peng Sum, BDS, MSc, Shibi Mathew, BSc, MSc, Chwee-Teck Lim, PhD
Enterococcus faecalis is frequently associated with post-treatment endodontic infections. Because adherence of bacteria to a substrate is the earliest stage in biofilm formation, eliciting the factors that links adherence of this bacterium to dentin would help in understanding its association with treatment-failed root canals. This investigation aimed to study the effects of endodontic irrigants on the adherence of E. faecalis to dentin. The bacteria adherence assay was conducted by using fluorescence microscopy, and the adhesion force was measured by using atomic force microscopy. There were significant increases in adherence and adhesion force after irrigation of dentin with ethylenediaminetetraacetic acid (EDTA), whereas sodium hypochlorite (NaOCl) reduced it. With the use of chlorhexidine (CHX), the force of adhesion increased, but the adherence assay showed a reduction in the number of adhering bacteria. The irrigation regimen of EDTA, NaOCl, and CHX resulted in the least number of adhering E. faecalis cells. This study highlighted that chemicals that alter the physicochemical properties of dentin will influence the nature of adherence, adhesion force, and subsequent biofilm formation of E. faecalis to dentin.
The Effect of Different Full-coverage Crown Systems on Fracture Resistance and Failure Pattern of Endodontically Treated Maxillary Incisors Restored with and without Glass Fiber Posts
Ziad Salameh, Roberto Sorrentino, Hani F. Ounsi, Walid Sadig, Fadi Atiyeh, Marco Ferrari
The aim of this study was to compare the fracture resistance and failure pattern of endodontically treated maxillary incisors restored using composite resin with or without fiber-reinforced composite (FRC) posts under different types of full-coverage crowns. The null hypothesis tested was that fracture resistance and the failure pattern of these teeth were not affected by the use of FRC posts or by the type of full-coverage crown. One hundred twenty maxillary incisors were endodontically treated and divided into 4 groups of 30 each. Each group was divided into two subgroups: restoration with or without fiber post. PFM crowns were placed in group 1, Empress II crowns in group 2, SR Adoro crowns in group 3, and Cercon crowns in group 4. Fracture tests were performed by loading specimens to fracture. Data were analyzed with two-way analysis of variance (α = 0.05). The type of crown was not a significant factor affecting fracture resistance (p = 0.4), whereas the presence of a post was (p = 0.001). Both the presence of post and the type of crown had a significant influence on the proportion of restorable versus unrestorable fractures. Although prosthodontics textbooks do not generally advocate the placement of fiber posts in endodontically treated incisors, the results of this study indicate that the use of fiber posts in such teeth increases their resistance to fracture and improves the prognosis in case of fracture.
Use of the Microscope in Endodontics: Results of a Questionnaire
Daniel D. Kersten, DDS, Pete Mines, DDS, Mark Sweet, DDS
The purpose of this study was to investigate the frequency and characteristics of operating microscope (OM) utilization among endodontists in the United States. The study also investigated how OM use has changed since a similar study was published nearly a decade ago. A web-based survey regarding OM usage was e-mailed to 2340 active members of the American Association of Endodontists (AAE) in the United States. Data from 1091 questionnaires indicated that 90% of the endodontists surveyed have access to and use the OM in their practice. The frequency of use as a function of years since completing endodontic training was as follows: <10 years, 95%; 10–15 years, 90%; 16–20 years, 82%; >21 years, 78%. Previous studies found that shorter operators needed to adopt a strained position to view mandibular molars. Our results indicated with strong correlation (r = 0.90) that shorter endodontists used the microscope more often than taller endodontists. The OM was used most frequently for root-end inspection, locating canal orifices, and root-end filling, respectively. Of the practitioners who used the OM, 59% used it without limitation, 86% used it equally between the maxillary and mandibular arch, and 84% used it as often as anticipated. The most common limitations to OM use were positional difficulty, limited field of view, and inconvenience, respectfully. The use of the OM by endodontists increased from 52% in 1999 to 90% in 2007.
Effects of Er:YAG Laser Irradiation on Biofilm-forming Bacteria Associated with Endodontic Pathogens In Vitro
Yuichiro Noiri, DDS, PhD, Tetsushi Katsumoto, DDS, PhD, Hiroyuki Azakami, PhD, Shigeyuki Ebisu, DDS, PhD
With the development of dental laser delivery systems that can enter into the root canals, it is possible to use Er:YAG lasers to remove the residual biofilm associated with infected root canals. We examined their effects against biofilms made of Actinomyces naeslundii, Enterococcus faecalis, Lactobacillus casei, Propionibacterium acnes, Fusobacterium nucleatum, Porphyromonas gingivalis, or Prevotella nigrescens in vitro. After Er:YAG laser irradiation with energy densities ranging between 0.38–0.98 J/cm2, the biofilm samples on hydroxyapatite disks were quantitatively and morphologically evaluated. The Er:YAG laser was effective against biofilms of 6 of the bacterial species examined, with the exception of those formed by L. casei. After irradiation, the numbers of viable cells in the biofilms were significantly decreased, whereas atrophic changes in bacterial cells and reductions in biofilm cell density were seen morphologically. Er: YAG lasers might be suitable for clinical application as a suppressive and removal device of biofilms in endodontic treatments.
Evaluation of Cutting Efficiency of Orthograde Ultrasonic Tips by Using a Nonstatic Model
Terence R. Dentkos, DDS, David W. Berzins, PhD
The purpose of this in vitro study was to evaluate the cutting efficiency of 4 orthograde ultrasonic tips and describe a nonstatic cutting model. Forty molars were extracted and decoronated. Each group contained 10 tips. The samples were fixed to a double pan balance that applied a constant vertical force of 40 g to the ultrasonic tips. The ultrasonic handpiece was mounted to a cyclic axial fatigue testing apparatus to generate a 3-mm horizontal movement of the ultrasonic tip during the cutting procedure. Three cutting cycles of 30 seconds were tested for each power setting of 3, 5, and 7. The weight of the samples was measured before and after the 3 cycles. The cutting efficiency was determined by the weight change caused by dentin removal. The Buc-1 ultrasonic tip had a significantly greater cutting efficiency than the other 3 tips at each of the 3 power settings (P < .05).
The Comparison of Gutta-Percha and Resilon Penetration into Lateral Canals with Different Thermoplastic Delivery Systems
Bekir Karabucak, DMD, MS, Aimee Kim, DMD, Vinne Chen, DDS, Mian K. Iqbal, DMD, MS
The aim of this study was to evaluate the ability of Obtura II (Obtura Spartan, Fenton, MO) and Calamus (Densply, Tulsa, OK) to fill artificially created lateral canals in simulated plastic teeth using standard gutta-percha, Flow 150 gutta-percha (Obtura Spartan, Fenton, MO), and Resilon (Resilon Research, LLC, North Branford, CT). Lateral canals were created at 2, 4, 6, 8, 10, and 12 mm from the apex in plastic teeth. The teeth were divided into eight groups. In group 1, teeth were filled with a single increment of Calamus; in group 2, canals were filled with Calamus in three increments. In group 3, Obtura II was used with a single increment of standard gutta-percha, whereas in group 4 Obtura II was used in three increments. Groups 5 and 6 were similarly filled as in the preceding groups. A multiple-comparison analysis of variance test followed by a Tukey post-hoc test were used to compare filling material penetration into the lateral canals and the experimental groups (p < 0.05). The results indicated that the flow of the filling material into lateral canals is a function of the viscoelastic properties of the filling material rather than the mechanical properties of the delivery systems. Our data also suggest that the Resilon filling material flows better into lateral canals when a single backfill technique is used.
Clinical Outcomes of Artificial Root-end Barriers with Mineral Trioxide Aggregate in Teeth with Immature Apices
David T. Holden, DMD, Scott A. Schwartz, DDS, Timothy C. Kirkpatrick, DDS, William G. Schindler, DDS, MS
The purpose of this retrospective study was to evaluate the clinical outcomes of ProRoot mineral trioxide aggregate used as an artificial apical barrier in teeth with immature apices. Twenty teeth from 19 patients were included in this study. A healed diagnosis was based on periapical index scores of 1 or 2 and no clinical signs or symptoms at recall examinations. Eighty-five percent (17/20) of these teeth were healed, and improvements in periapical index scores at recall appointments were shown to be statistically significant (P < .001, Wilcoxon signed-rank test). Chi-square test indicated that age, gender, primary treatment versus retreatment, presence of preoperative lesion, and differences in recall times did not significantly influence healing outcome. Overall, these results indicated that the mineral trioxide aggregate apical barrier technique is a successful method for obturating teeth with immature apices.
Antimicrobial Efficacy of a Polymeric Chlorhexidine Release Device Using In Vitro Model of Enterococcus faecalis Dentinal Tubule Infection
Yoon Lee, DDS, MSD, Seung Hyun Han, MS, PhD, Sang-Hee Hong, DDS, MSD, Jin-Kyung Lee, DDS, Hye Ji, BS, Kee-Yeon Kum, DDS, PhD
This study aimed to assess the antimicrobial efficacy of a novel polymeric chlorhexidine-controlled release device as an intracanal medicament. One hundred cylindrical dentin blocks prepared from human single-rooted teeth were inoculated with Enterococcus faecalis for 3 weeks. The intracanal medicaments tested were calcium hydroxide, a polymeric chlorhexidine-controlled release device (PCRD), a polymeric controlled release device without chlorhexidine (CHx), 0.2% CHx solution, and sterile saline. Dentin samples (at 200-μm and 400-μm depths) were collected from the medicated canal lumens after 1 week of medication with sterile LightSpeed files and placed in growth medium. Bacterial growth was assessed spectrophotometrically by analysis of optical density (OD) after 24 hours of incubation. The OD values at both depths were significantly lower in the PCRD group than in the other experimental groups (P < .001). These results indicate that a PCRD can be an effective intracanal medicament against E. faecalis.
Biologically Based Treatment of Immature Permanent Teeth with Pulpal Necrosis: A Case Series
Il-Young Jung, DDS, MS, Seung-Jong Lee, DDS, MS, Kenneth M. Hargreaves, DDS, PhD
This case series reports the outcomes of 8 patients (ages 9–14 years) who presented with 9 immature permanent teeth with pulpal necrosis and apical periodontitis. During treatment, 5 of the teeth were found to have at least some residual vital tissue remaining in the root canal systems. After NaOCl irrigation and medication with ciprofloxacin, metronidazole, and minocycline, these teeth were sealed with mineral trioxide aggregate and restored. The other group of 4 teeth had no evidence of any residual vital pulp tissue. This second group of teeth was treated with NaOCl irrigation and medicated with ciprofloxacin, metronidazole, and minocycline followed by a revascularization procedure adopted from the trauma literature (bleeding evoked to form an intracanal blood clot). In both groups of patients, there was evidence of satisfactory postoperative clinical outcomes (1–5 years); the patients were asymptomatic, no sinus tracts were evident, apical periodontitis was resolved, and there was radiographic evidence of continuing thickness of dentinal walls, apical closure, or increased root length.