Occurrence of Actinomyces in Infections of Endodontic Origin
Xia and Baumgartner
Patterns of Endodontic Care for a WashingtonStatePopulation
Hull, Robertson, Steiner and del Aguila
Removal of Organic Debris from Bovine Dentin Shavings
Kamburis, Barker, Barfield and Eleazer
The Effect of Passive Ultrasonic Activation of 2% Chlorhexidine or 5.25% Sodium Hypochlorite Irrigant on Residual Antimicrobial Activity in Root Canals
Diener Weber, McClanahan, Miller, Diener-West and Johnson
Effectiveness of Selected Materials Against Enterococcus faecalis: Part 3. The Antibacterial Effect of Calcium Hydroxide and Chlorhexidine on Enterococcus faecalis
Lin, Mickel and Chogle
Analysis of Mechanical Preparations in Extracted Teeth Using ProTaper Rotary Instruments: Value of the Safety Quotient
Blum, Machtou, Ruddle and Micallef
Effect of MTAD of Enterococcus faecalis-Contaminated Root Canals of Extracted Human Teeth
Shabahang and Torabinejad
Comparison of Two Techniques for Removing Fiber Posts
Gesi, Magnolfi, Goracci and Ferrari
Cytotoxicity Testing of Endodontic Sealers: A New Method
Camps and About
Comparison of Apical Transportation in Four Ni-Ti Rotary Instrumentation Techniques
Iqbal, Maggiore, Suh, Edwards, Kang and Kim
Reliability of the Dye Penetration Studies
Camps and Pashley
Adhesion of Endodontic Sealers: Scanning Electron Microscopy and Energy Dispersive Spectroscopy
Saleh, Ruyter, Nat., Philos., Haapasalo and Ørstavik
Adhesion of Human Fibroblasts to Root-End-Filling Materials
Camp, Jeansonne and Lallier
Toothache of Nonodontogenic Origin: A Case Report
Mascia, Brown and Friedman
Occurrence of Actinomyces in Infections of Endodontic Origin
Tian Xia, DDS, and J. Craig Baumgartner, DDS, PhD
Species of Actinomyces have been associated with endodontic treatment that failed to heal. In this study polymerase chain reaction was used with a pair of universal primers for Actinomyces and species-specific primers to evaluate the contents of infected root canals and aspirates from abscesses or cellulitis for the presence of Actinomyces israelii, A. naeslundii, and A. viscosus. DNA was extracted from 131 clinical samples. DNA from 2 of the original 131 samples was not available for polymerase chain reaction with the universal primer for Actinomyces and A. naeslundii. DNA reacting with the universal primer for Actinomyces was detected in 72 of 129 (55.8%) clinical samples. Of those 41or 51 (80.4%)were from infected root canals, 22 of 48 (45.8%)were from abscesses, and 9 of 30 (30%) were associated with cellulites. A. viscosus was detected in 42 of 131 (32.1%) clinical samples. Of those 31 of 52 (59.6%) were from infected root canals, 6 of 43 (14%) were from abscesses, and 5 of 36 (13.9%) were associated with cellulites. A. israelii was detected in 31 of 131 (23.7%) clinical samples. Of those 14 of 52 (26.9%) were from infected root canals, 11 of 43 (25.6%) were from abscesses, and 6 of 36 (16.7%) were associated with cellulites. A. naeslundii was detected in 11 of 131 (8.5%) clinical samples. Of those 7 of 51 (13.7%) were from infected root canals, 2 of 48 (4.2%) were from abscesses, and 2 of 30 (6.7%) were associated with cellulites.
Patterns of Endodontic Care for a WashingtonStatePopulation
Troy E. Hull, DDS, MSD, Paul B. Robertson, DDS, MS, James C. Steiner, DDS, MSD, and Michael A. del Aguila, PhD
Endodontic care, provided by 3,402 dental offices, was assessed from claims data maintained by the Washington Dental Service for 1999. Approximately 5.7 million dental procedures were provided to 880,317 patients by 2,796 general practitioners, 105 endodontists, and 494 other specialists. Of all dental services, 63, 321 (1%) were endodontic procedures involving 52, 911 (6%) patients. General dentists, endodontists, and other specialists performed 64.7%, 33.7%, and 1.6% of endodontic procedures, the majority of which were root canal therapy. The most frequent tooth types treated by root canal thereapy were mandibular first molars (17.0%), maxillary first molars (15.2%), mandibular second molars (11.8%), maxillary second bicuspids (10.3%), maxillary second molars (9.1%), maxillary central and lateral incisors (8.8%), and mandibular second bicuspids (8.0%). Direct and indirect pulp caps by generalists and conventional retreatement and surgical therapy by endodontists made up the majority of the remaining endodontic services. Men had a greater procedure rate than women for most endodontic procedures.
Removal of Organic Debris from Bovine Dentin Shavings
J.J. Kamburis, DMD, T.H. Barker, PhD, R. D. Barfield, DMD, and P. D. Eleazer, DDS, MS
A common problem with root canal failures is chronic inflammation at the apex caused by overfilling of root canal materials. Dentin fillings have been suggested as an apical plug to create a biocompatible barrier between the filling material and the periapical tissue. Unfortunately residual organic material, such as pulp remnants or bacteria, still may be part of the fillings. Dentin fillings removed from the tooth, cleaned, and then used to form a barrier might serve as an effective barrier. The purpose of this study was to evaluate methods of cleaning dentin of organic debris. NaOCI, sodium dodecyl sulfate, and 1% Triton X-100 were used to treat dentin shavings and were evaluated by a micro bicinchoninic acid protein analysis assay. Two series of experiments were performed. One compared the effect of temperature while using phospate-buffered saline as a control and second compared exposure times. The percentage of protein extracted from dentin samples increased with temperature. Sodium hypochlorite at room temperature extracted 24.6%, NaOCI at 37°C extracted 26.9%, and NaOCI at 70°C extracted 33.9%. Only NaOCI at 37°C and 70°C showed statistically significant differences from phosphate-buffered saline at room temperature with p-values of 0.028 and 0.019, respectively. The exposure time series showed a difference between a phosphate-buffered saline solution and 6.25% NaOCI. NaOCI removed approximately 90% of protein compared with 60% for the phosphate-buffered saline. A 10-min exposure to 70°C 6.25% NaOCI may be an efficient means of removing organic material from dentin shavings.
The Effect of Passive Ultrasonic Activation of 2% Chlorhexidine or 5.25% Sodium Hypochlorite Irrigant on Residual Antimicrobial Activity in Root Canals
Carol Diener Weber, DDS, MS, Scott B. McClanahan, DDS, MS, Glenn A. Miller, PhD, Marie Diener-West, PhD, and James D. Johnson, DDS, MS
Ninety-four single-canal roots were prepared using the step-down technique. Forty-two canals were irrigated with 2% chlorhexidine, 42 canals with 5.25% sodium hypochlorite (NaOCI), and 10 control canals with phosphate-buffered saline (PBS). The chlorhexidine and NaOCI groups were each then equally divided into a final irrigation group and a 1-min passive ultrasonic irrigation group. Canals were enlarged with a Parapost drill. The apical 3-5 mm was covered with nail polish. Canals were rinsed with PBS, dried, refilled with PBS, and stored. At 6h, 20 μl of fluid was pipetted from each canal and placed into wells on agar plates, which were inoculated with Streptococcus sanguinis. The plates were incubated, and zones of inhibition were measured. Sampling was repeated at 24, 48, 72, 96, 120, 144, and 168 h. Residual antimicrobial activity with 2% chlorhexidine was statistically significantly superior to 5.25% NaOCI with irrigation alone and with final passive ultrasonic activation (p < 0.001). Chlorhexidine experimental groups demonstrated residual antimicrobial activity for as long as 168 h.
Effectiveness of Selected Materials Against Enterococcus faecalis: Part 3. The Antibacterial Effect of Calcium Hydroxide and Chlorhexidine on Enterococcus faecalis
Yu-heng Lin, DDS, MSD, André K. Mickel, DDS, MSD, and Sami Chogle, BDS, MSD
It has been found that Enterococcus faecalis is most commonly isolated in failed endodontic treatment. Irrigation with chlorhexidine gluconate has been suggested based on its antimicrobial effect and substantivity. Calsium hydroxide also is an effective antimicrobial agent because of its high alkalinity. The purpose of this study was to test the individual and combined effect of calcium hydroxide and chlorhexidine against E. faecalis. The agar-diffusion test was performed on Mueller-Hinton plates. Paper disks were impregnated with: (a) CaOH powder with sterile water; (b) Pulpdent®; (c) 0.12% Peridex®; (d) CaOH powder with Peridex®; and (e) Pulpdent® with Peridex®. Ampicillin served as a control. The plates were incubated at 37° C for 72 h. Peridex® showed significantly larger zones of inhibition compared with CaOH. No statistically significant difference was found between Peridex® and the combination of CaOH and Peridex®.
Analysis of Mechanical Preparations in Extracted Teeth Using ProTaper Rotary Instruments: Value of the Safety Quotient
J-Y Blum, P. Machtou, C. Ruddle, and J. P. Micallef
The purpose of this study was to apply the Endographe to analyze the vertical forces and torque developed during mechanical preparations in extracted teeth. The data collected in this study may be used to calculate the safety quotient (SQ) as proposed by J.T. McSpadden. The SQ formula is defined as the torque required to break a file at D3 divided by the mean working torque required to cut dentin. The Endographe is a unique force-analyzer device equipped to measure, record, and generate graphs of the vertical forces and torque exerted during root canal preparation. All preparations were performed by endodontists in roots with narrow, more restrictive canals, larger, more open canals, or in roots sectioned in two halves. All canals, including the sectioned canals, were prepared with ProTaper files in accordance with the manufacturer’s guidelines for use. For narrow canals, the mean values of the generated vertical forces (g) and torque (g.cm) varied from 80 (+ 20) g (SX) to 232 (+ 60) g (F2) and from 80 (+ 24) g.cm (F1) to 150 (+ 45) g.cm (S2), respectively. For large canals, the mean values of the generated vertical forces (g) and torque (g.cm) varied from 80 (+ 20) g (SX) to 340 (+ 20) g (F1) and from 31 (+ 9) g.cm (S2) to 96 (+ 35) g.cm (SX), respectively. The SQ varied from 0.93 to 7.95 for narrow canals and from 1.58 to 14.50 for large canals. The SQ is intended to provide values that can be analyzed to predict whether a rotary file will have a tendency to break or will work safely during clinical use. However, if the formula is going to provide useful information, it must index the “rotation to failure torque” with the “mean working torque” at a specific location along the cutting blades of a file. Additionally, this mathematical formula does not account for factors such as the concentration of forces, the way the instruments are used, or the wear of the instruments. A precise protocol for canal preparation should emphasize using small flexible stainless steel hand files to create or verify that within any portion of a root canal there is sufficient space for rotary instruments to follow. When there is a confirmed smooth, reproducible glide path, then a “secured” space exists to safely guide the more flexible terminal extent of a rotary NiTi file. Endogrammes provide an innovative approach to the analysis of mechanical preparations and suggest that the ProTaper shaping files are best used with lateral forces to decrease the coronal screwing effect. The ProTaper finishing files should be used with slow penetration and be introduced only into canals that have a confirmed smooth and reproducible glide path. When any part of the overall length of a canal has been secured, then the number of instruments, the time spent utilizing each instrument, and the overall time progressing through a sequence of instruments to shape this region of the canal is reduced.
Effect of MTAD of Enterococcus faecalis-Contaminated Root Canals of Extracted Human Teeth
Shahrokh Shabahang, DDS, MS, PhD, and Mahmoud Torabinejad, DMD, MSD, PhD
The purpose of this investigation was to compare the antimicrobial effect of MTAD (a mixture of a tetracycline isomer, an acid, and a detergent) with that of NaOCI with and without EDTA. Eighty-five extracted human teeth were contaminated with Enterococcus faecalis for 4 weeks. After biomechanical instrumentation using 1.3% or 5.25% NaOCI as root canal irrigant, the root canal and the external surface of each tooth were exposed to a 5-min application of MTAD, 1.3% NaOCI, 5.25% NaOCI or a 1-min application of EDTA followed by irrigation with 5 ml of 1.3% NaOCI or 5.25% NaOCI. Teeth or dentin shavings were cultured to determine presence or absence of the test bacteria. Fisher’s exact test showed that the combination of 1.3% NaOCI as a root canal irrigant and MTAD as a final rinse was significantly more effective against E. faecalis than the other regimens. The x2 test showed no difference between the other regimens.
Comparison of Two Techniques for Removing Fiber Posts
A. Gesi, DDS, S. Magnolfi, DDS, C. Goracci, DDS, MS, and M. Ferrari, MD, DDS, PhD
The purpose of this study was to evaluate the time needed to remove several types of fiber posts using two different bur kits. Estimates refer to the time needed to pass the fiber post until arriving at the gutta-percha. Sixty extracted anterior teeth were treated endodontically. A post space with a standard depth of 10 mm was prepared in each root canal. The sample was randomly divided into 3 groups of 20 specimens each. Three different types of posts were cemented: group 1, Conic 6% tapered fiber posts (Ghimas); group 2, FRC Poster fiber posts (Ivoclar-Vivadent); and group 3, Composipost carbon fiber posts (RTD). To remove the post, for half of each group’s specimens the burs from the RTD fiber posts removal kit were used (subgroup A). From the other half of the teeth in each group (subgroup B), posts were removed by using a diamond bur and a Largo bur. Composipost carbon fiber posts (group 3) took significantly less time to remove than the other two types of posts (p < 0.05). For the bur kits, the procedure involving the use of a diamond and a Largo bur (subgroup B) was significantly faster (p < 0.05). The interaction between the type of post and the type of bur kit used was not significant (p > 0.05).
Cytotoxicity Testing of Endodontic Sealers: A New Method
Jean Camps, DCD, PhD, and Imad About, PhD
The purpose of this study was to compare ISO standards versus a new technique for in vitro evaluation of cytotoxicity of root canal sealers. The cytotoxicity of AH Plus, Cortisomol, and Sealapex was first recorded according to ISO standards on L 929 fibroblasts by the MTT assay. In parallel, 30 single-rooted teeth were cut at the cementum enamel junction (CEJ), and the roots were prepared and sterilized before filling with the lateral condensation using one of three sealers (n =10). The apexes of the roots were dipped into 1 ml of minimum essential medium for 1, 2, and 30 days renewing the medium every other day. After 24-h contact between the medium and the filled roots, the medium was used to measure the cytotoxicity on L 929 with the MTT assay. ISO standards always gave a statistically higher cytotoxicity than the root-dipping technique (p < 0.0001), whatever the sealer and the exposure time. The ISO standards showed statistically significant differences among the sealers (p < 0.0001). AH Plus was noncytotoxic, Cortisomol showed a high cytotoxicity decreasing over time (p < 0.0001), and Sealapex displayed a high cytotoxicity that did not decrease over time (NS). The new technique showed statistically significant difference among the sealers (p = 0.001), but the differences were so small that they were likely not clinically relevant. The high cytotoxicity of Sealapex decreased over time but the cytotoxicity of AH Plus and Cortisomol did not. The results show that the ISO standards may strongly over-evaluate the cytotoxicity of the endodontic sealers, emphasize the difference among the sealers, and may clinically correspond to a large overfilling. The new technique reduces the discrimination of the test and may clinically correspond to a classical filling. Therefore, both methods might be considered as clinically relevant, corresponding to classical and overfilling conditions.
Comparison of Apical Transportation in Four Ni-Ti Rotary Instrumentation Techniques
Mian K. Iqbal, DMD, MS, Francesco Maggiore, DDS, Brian Suh, DMD, Kevin R. Edwards, DDS, Jamie Kang, DMD, and Syngcuk Kim, DDS, M. Phil, PhD
A new radiographic technique was used to compare apical transportation in four Ni-Ti rotary instrumentation sequences. Mesiobuccal canals of 60 extracted mandibular molars were randomly divided into four groups. Groups 1 and 3 were instrumented by crown-down and groups 2 and 4 by step-back technique with 0.06 ProFiles series 29 to size 6. In groups 3 and 4 Greater Taper files were first used in a crown-down manner. The central axes of initial and final instruments were radio-graphically superimposed to measure loss of working length (WL) and transportation at 0, 0.5, 1, 3, and 5 mm from WL. ANOVA test showed no significant differences among groups regarding degree of transportation or loss of WL. Transportation was negatively correlated with radius of curvature at 0.5 and 5 mm from WL. The results indicate that the operational sequence of ProFiles or preinstrumentation with GT files has no effect on degree of transportation and loss of WL.
Reliability of the Dye Penetration Studies
Jean Camps, DCD, PhD, and David Pashley, DMD, PhD
The purpose of this study was to compare the classical dye-penetration method to a dye-extraction method, with a fluid-filtration method as control. Forty teeth were prepared with a ProFile device and divided into four groups (n = 10 per group) according to the sealer used for the lateral condensation: Pulp Canal Sealer, Sealapex, AH Plus, and Ketac-Endo. The apical seal was evaluated on the same teeth with all three methods, successively: a fluid-filtration method, a dye-penetration method with 2% methylene blue, and a new method where the roots were dissolved in 65% nitric acid to extract the methylene blue before reading the absorbance of the solution. The classical dye penetration did not show any difference among the sealers and showed no correlation with the two other techniques. The fluid filtration (p < 0.01) and the dye extraction (p < 0.01) showed that Sealapex displayed the highest apical leakage. The correlation between the results obtained with these two methods was significant (p = 0.001 and r = 0.7). This study showed the imitation of the classical dye-penetration studies and that the dye-extraction, i.e. dissolution, method gave the same results as fluid filtration but saved much laboratory time.
Adhesion of Endodontic Sealers: Scanning Electron Microscopy and Energy Dispersive Spectroscopy
Iman M. Saleh, BDS, MSc, I. Eystein Ruyter, Dr. Rer. Nat., Dr. Philos., Markus P. Haapasalo, DDS, PhD, and Dag Ørstavik, DDS, PhD
The microscopic details of the debonded interfaces between endodontic sealers and dentin or gutta-percha were assessed in this study. Dentin, conditioned with 37% H3PO4 for 30 s, 25% citric acid for 30 s, 17% EDTA for 5 min, or a rinse with 10 ml of distilled H2O (control), and gutta-percha surfaces were coated with freshly mixed sealer: Grossman’s sealer, Apexit, Ketac-Endo, AH Plus, RoekoSeal Automix, or RoekoSeal Automix with an experimental primer. The surfaces were pressed together and the sealers were allowed to set. After tensile bond strength testing, the morphological aspects of the fractured surfaces were assessed by scanning electron microscopy and energy dispersive spectroscopy. The energy dispersive spectroscopy successfully traced sealer components to the debonded surfaces. Some of the sealers penetrated into the dentinal tubules when the dintin surface had been pretreated with acids. However, these sealer tags remained occluding the tubules after bond failure in some instances only (Grossman’s sealer, RoekoSeal Automix with an experimental primer, AH Plus/EDTA). Penetration of the endodontic sealers into the dentinal tubules when the smear layer was removed was not associated with higher bond strength.
Adhesion of Human Fibroblasts to Root-End-Filling Materials
Mark A. Camp, DDS, MS, Billie G. Jeansonne, DDS, PhD, and Thomas Lallier, PhD
This study evaluated the attachment of cultured explants of human periodontal ligament fibroblasts and gingival fibroblasts to different root-end-filling materials. Although periodontal ligament and gingival fibroblasts initially attached avidly to Geristore®, these same cells displayed no significant attachement to ProRootTM, Tytin® amalgam, or SuperEBATM. With further incubation on Geristore®, the attachment of both periodontal ligament and gingival fibroblasts improved and these cells proliferated. In contrast, no improvement in attachment or proliferation was observed for cells incubated for greater times with ProRootTM, Tytin® amalgam, or SuperEBATM. Because the attachment characteristics of these two groups of fibroblasts were identical, we examined the potential role of the extracellular matrix family of receptors (integrins) on the attachement of gingival fibroblasts. Gingival fibroblast attachement to collagen type 1 was determined to be dependent on χ1β1 and χ2β1 integrins, whereas their attachment to the RGD-binding sequence of fibronectin and vitronectin was partially inhibited by antibodies to the β1 and χV integrin subunits. However, attachement of gingival fibroblasts to Geristore® was not reduced by the addition of any of the attachment-perturbing anti-integrin antibodies examined. Thus, gingival fibroblasts attach to Geristore®, but this attachment was mediated by mechanisms other than integrins.
Toothache of Nonodontogenic Origin: A Case Report
Philip Mascia, DDS, Bruce R. Brown, DDS, and Seymour Friedman, DDS
This article describes the diagnosis and treatment of a patient exhibiting nonodontogenic tooth pain. A 25-yr old female patient presented to postgraduate endodontics, SUNY at Stony Brook, for evaluation and treatment of pain associated with the upper and lower left quadrants. After thorough intraoral and extraoral examinations, it was determined that the pain was referred to the dentition from a trigger point in the masseter muscle. An extraoral injection of 3% Carbocaine was administered into the trigger point, and the pain abated within 5 min. The patient has experienced no recurrence of this pain for 12 months. Consideration of nonodontogenic dental pain should be included in a differential diagnosis.