Digital and Advanced Imaging in Endodontics: A Review
Madhu K. Nair, DMD, MS, Lic. Odont. (Sweden), PhD, Dipl. ABOMR, Umadevi P. Nair, DMD, MDS
This review provides an overview of digital radiography as it exists, including advanced imaging such as computed tomography (CT), cone beam volumetric imaging, and micro-CT as relevant to the practice of endodontics. An evidence-based approach to adoption of different imaging technologies is included to assist the practitioner with the selection process of imaging modalities. Commonly used imaging terminology is introduced, as well as the advantages and disadvantages of image processing. New image reconstruction techniques have been introduced that provide information three-dimensionally to the clinician for routine endodontic and surgical treatment planning. The age of three-dimensional imaging and image processing is here. Limitations and advantages of newly introduced imaging modalities are discussed briefly.
Anesthetic Efficacy of Lidocaine/Meperidine for Inferior Alveolar Nerve Blocks in Patients with Irreversible Pulpitis
Jason Bigby, DDS, MS, Al Reader, DDS, MS, John Nusstein, DDS, MS, Mike Beck, DDS, MA
The purpose of this prospective, randomized, single-blind study was to compare the anesthetic efficacy of lidocaine with epinephrine to lidocaine plus meperidine with epinephrine for inferior alveolar nerve blocks (IAN) in patients with mandibular posterior teeth experiencing irreversible pulpitis. Forty-eight emergency patients diagnosed with irreversible pulpitis of a mandibular posterior tooth randomly received, in a single-blind manner, 36 mg of lidocaine with 18 μg epinephrine or 36 mg of lidocaine with 18 μg of epinephrine plus 36 mg meperidine with 18 μg epinephrine, using a conventional inferior alveolar nerve block. Endodontic access was begun 15 minutes after solution deposition, and all patients were required to have profound lip numbness. Success was defined as no or mild pain (visual analog scale recordings) upon endodontic access or initial instrumentation. The success rate for the inferior alveolar nerve block using the lidocaine solution was 26%, and for the lidocaine/meperidine solution, the success rate was 12%. There was no significant difference (p = 0.28) between the two solutions. In conclusion, for mandibular posterior teeth with irreversible pulpitis, the addition of 36 mg of meperidine to a lidocaine solution administered in a conventional IAN block did not improve the success rate over a standard lidocaine solution.
The Effect of Preoperative Acetaminophen or a Combination of Acetaminophen and Ibuprofen on the Success of Inferior Alveolar Nerve Block for Teeth with Irreversible Pulpitis
Staci R. Ianiro, DDS, Billie G. Jeansonne, DDS, PhD, Sandre F. McNeal, MPH, Paul D. Eleazer, DDS MS
This study compared preoperative administration of acetaminophen or a combination of acetaminophen and ibuprofen versus placebo for potential increased effectiveness of inferior alveolar nerve (IAN) block anesthesia. There were 40 patients with irreversible pulpitis randomly assigned to a drug or placebo group. Thirty minutes after ingestion of medication, an IAN block was administered. A cold test was done 15 minutes after the block, and if the patients had no sensitivity, endodontic therapy was initiated. If the patient had no pain on access, the IAN was recorded as successful. If the patient had sensitivity to cold or to the access procedure, it was recorded as a failure. Overall success was 60% for all three groups. Success was 71.4% for the acetaminophen group, 75.9% for the acetaminophen and ibuprofen group, and 46.2% for the placebo group. There was no significant difference between the groups; however, there was a trend toward higher success in the medication groups.
The Effect of Operator Experience in Locating Additional Canals in Maxillary Molars
Jim Corcoran, DDS, Michael J. Apicella, DDS, Pete Mines, DDS
The purpose of this study was to determine the influence of operator experience on the ability to locate and fill extra canals in maxillary first and second molars in vivo. The number of canals located and filled from maxillary first and second molars was recorded from three endodontic residents during the first 6 months of their training, and then compared to the last 6 months of their training in a 2-yr endodontic residency program. Data from each resident was collected and compiled together. The study showed a statistically greater percentage of additional canals located and filled by residents in their last 6 months, as compared to the same residents in their first 6 months in maxillary first and second molars (p < 0.05). Therefore, operator experience was found to improve the ability to locate and fill additional canals in maxillary first and second molars.
Co-Expression of Cyclooxygenase-2 and Vascular Endothelial Growth Factor in Inflamed Human Pulp: An Immunohistochemical Study
Günseli Güven, DDS, PhD, Ceyhan Altun, DDS, PhD, Ömer Günhan, DDS, PhD, Taskin Gurbuz, DDS, PhD, Feridun Basak, DDS, PhD, Erman Akbulut, DDS, PhD, Zafer C. Cehreli, DDS, PhD
Recent data from the medical literature indicates that cyclooxygenase-2 (COX-2) plays a key role in the production of vascular endothelial growth factor (VEGF), a glycoprotein that has the ability to increase the permeability of blood vessels and to induce angiogenesis. This study was undertaken to investigate the immunohistological co-expression of COX-2 and VEGF in inflamed human pulp, in conjunction with the expression of CD34, a transmembrane glycoprotein expressed in endothelial cells. Pulp tissue of extracted carious human third molars with a recent history of spontaneous pain were collected and processed for immunostaining of COX-2, VEGF, and CD34 using the biotin-streptoavidin method. Healthy pulp samples served as controls. COX-2 expression was not observed in healthy pulps, whereas all inflamed pulps demonstrated COX-2-expressing cells. Similarly, VEGF was not expressed in normal pulp tissue, but was strongly positive in inflamed pulps. CD34 was expressed in the endothelium of both normal and inflamed pulp tissues. Co-expression of COX-2 and VEGF in all consecutive sections of inflamed pulps could be suggestive of a possible release of VEGF via a COX-2-dependent pathway.
The Role of Apical Size Determination and Enlargement in the Reduction of Intracanal Bacteria
André K. Mickel, DDS, MSD, Sami Chogle, BDS, DDS, MSD, Justin Liddle, Kirk Huffaker, DDS, Jefferson J. Jones, DDS
The master apical preparation size in root canal therapy is debatable despite considerable research. The present study compared file sizes that bind at the apex before and during crown-down preparation and assessed the relation between apical size and extent of intracanal bacterial load. There were 100 single-rooted teeth biomechanically prepared after inoculation with Enterococcus faecalis. Canals were preflared, and apical size was ascertained by the first file to bind (FAB) at the working length (WL). During crown-down preparation, the first crown-down file to reach the apex during instrumentation was noted (CDF). Teeth were then divided into three master apical file size groups of CDF + 1, CDF + 2, and CDF + 3. Positive controls were inoculated postinstrumentation, whereas negative controls were instrumented without inoculation (n = 5). The samples were then cultured for intracanal bacterial counts. Fifteen samples and four controls were analyzed under SEM. The data were analyzed using ANOVA, Student’s t-test, and χ2 tests. The CDF was demonstrated to be an average of four file sizes larger than the FAB (p < 0.05). There was a significant increase in the number of samples with negative cultures from CDF + 1 to CDF + 3. SEM observation revealed bacteria on dentinal walls and in tubules even in most negative canal cultures.
The Antimicrobial Effect of MTAD, Sodium Hypochlorite, Doxycycline, and Citric Acid on Enterococcus faecalis
Trisha A. Krause, DMD, MS, Frederick R. Liewehr, DDS, MS, Chin-Lo Hahn, PhD, DDS
This study compared the antimicrobial effect of MTAD, two of its components, doxycycline and citric acid, and sodium hypochlorite (NaOCl) in two in vitro models on Enterococcus faecalis. In the bovine tooth model, the lumens of 30 bovine dentin discs were infected with E. faecalis for 2 weeks before treating with either one of the experimental irrigants or saline. Bacteria in the shavings were collected with two sizes of burs and enumerated after overnight culturing. Zones of inhibition were recorded in the agar diffusion model for each irrigant. In the tooth model, NaOCl and doxycycline were more effective than control in killing E. faecalis at the shallow bur depth, but at the deeper bur depth only NaOCl was superior. In the agar diffusion model, NaOCl produced less inhibition than MTAD or doxycycline.
Influence of Moisture on the Apical Seal of Root Canal Fillings With Five Different Types of Sealer
Matthias Johannes Roggendorf, DMD, Johannes Ebert, DMD, Anselm Petschelt, DMD, PhD, Roland Frankenberger, DMD, PhD, FICD
The aim of this study was to evaluate the influence of moisture on apical leakage using five different types of sealer. There were 120 single-rooted teeth instrumented to .02/#60 and randomly assigned to 10 experimental groups, one control group (AH Plus, lateral condensation) (n = 10) or positive/negative controls (n = 5). Before obturation teeth were dried thoroughly, followed by recontamination with moisture in a wet chamber (moist groups; 37°C for 7 days). The teeth of the experimental groups (a, dry; b, moist) were obturated with sealer (groups 1, AH Plus; 2, Apexit; 3, Ketac-Endo; 4, RoekoSeal; 5, Tubli-Seal) and a single gutta-percha cone .02/#55. Teeth were centrifuged (30 × g for 3 minutes) in 5% methylene blue. Linear dye penetration was measured under a stereomicroscope. Moisture led to less microleakage for Apexit, RoekoSeal, and Tubli-Seal and higher values for AH Plus and Ketac-Endo. Multifactorial ANOVA displayed a significant dependence of leakage on sealer (p < 0.001) and the combination sealer or moisture (p < 0.01). It depends on the sealer type in which way moisture affects the apical seal.
Separate Whitening Effects on Enamel and Dentin After Fourteen Days
Gerard Kugel, DMD, MS, PhD, Jason Petkevis, BS, Sevil Gurgan, DDS, PhD, Eileen Doherty, MS
The purpose of this study was to investigate the mechanism of action of a bleaching agent, as it relates to enamel and dentin. Twenty-six extracted human molar teeth were sectioned at the cemento-enamel junction and were randomly assigned to two groups. L*a*b* readings were taken with a spectrophotometer: on buccal surfaces of the crown, at enamel and dentin. The teeth were exposed to carbamide peroxide or placebo gel and L*a*b* scores were again recorded to determine color changes. Treatments were compared using ancova test with baseline color as the covariate. Relative to placebo, buccal surfaces exhibited the greatest Δb* and ΔL* color change. On buccal surfaces, the adjusted mean (SE) treatment differences were −7.8 (1.00) for Δb* and 5.7 (0.97) for ΔL, with groups differing significantly (p < 0.0001). On enamel surfaces, treatment differences were −3.6 (0.61) for Δb* and 4.6 (0.80) for ΔL* (p < 0.0001). Dentin exhibited the least color improvement. Adjusted mean (SE) treatment differences were −1.9 (0.87) for Δb* and 2.4 (1.10) for ΔL*, with groups differing significantly (p < 0.02) on dentin color change. The majority of color change seen on the buccal surface of tooth crowns exposed to carbamide peroxide 15% was because of the color change in enamel. As compared to enamel, dentin was less affected after 14 days.
Efficacy of Two Rotary NiTi Instruments in the Removal of Gutta-Percha During Root Canal Retreatment
Abdulhamied Y. Saad, BDS, HDD, PhD⁎, Solaiman M. Al-Hadlaq, BDS, MS, PhD†, Nasser H. Al-Katheeri, BDS†
The aim of this study was to evaluate the efficacy of ProTaper and K3 in the removal of gutta-percha during root canal retreatment in comparison with hand Hedstrom files. Time of gutta-percha removal and amount of apically extruded debris were also evaluated. Sixty extracted single-rooted anterior teeth and premolars were instrumented and obturated with laterally condensed gutta-percha technique. The teeth were cleared and randomly divided into three groups of 20 teeth each. The roots were split longitudinally, digital images were created using a scanner, and the areas of remaining filling material were traced using Ulead Photoimpact7 then calculated using SigmaScan software. The results indicated that the two rotary nickel-titanium instruments left significantly less remaining filling material than hand instruments (p < 0.001). The ProTaper and K3 required significantly less time for filling material removal than hand instruments (p < 0.001). There was no statistically significant difference among the three techniques regarding the amount of apically extruded debris (p = 0.159). In conclusion, ProTaper and K3 were found to be effective and faster in removing gutta-percha.
Comparison of 5.25% Sodium Hypochlorite, MTAD, and 2% Chlorhexidine in the Rapid Disinfection of Polycaprolactone-Based Root Canal Filling Material
Mathew J. Royal, DDS, Anne E. Williamson, DDS, MS, David R. Drake, MS, PhD
The purpose of this investigation was to compare the effectiveness of 5.25% sodium hypochlorite, MTAD, and 2% chlorhexidine in the rapid disinfection of Resilon pellets. Resilon pellets were randomly selected, contaminated with Enterococcus faecalis, and disinfected with 5.25% sodium hypochlorite, MTAD, or 2% chlorhexidine. Positive and negative controls were used. All samples were air dried, washed in sterile water, placed in centrifuge tubes containing BHI broth, and incubated at 37°C for up to 7 days. Broths were visually checked for turbidity and scored for growth. Samples from each experimental and control group were randomly chosen, plated, incubated at 37°C, and checked visually for growth. If growth occurred, a gram stain was performed to identify bacterial species. Results indicate that 5.25% sodium hypochlorite, MTAD, and 2% chlorhexidine were all effective in the rapid disinfection of Resilon and gutta-percha pellets, and a 1-minute immersion was sufficient to disinfect.
Enterococcus faecalis Type Strain Leakage through Root Canals Filled with Gutta-Percha/AH Plus or Resilon/Epiphany
Gerhard Baumgartner, med dent, Matthias Zehnder, Dr. med dent, PhD, Frank Paqué, Dr. med dent
The aim of this in vitro study was to compare leakage of Enterococcus faecalis ATCC 29212 through root canals of single-rooted extracted human mandibular premolars filled with either gutta-percha/AH Plus or Resilon/Epiphany using the continuous wave of condensation technique. Test and control teeth were suspended in an experimental bacterial leakage setup for 50 days. Kaplan-Meyer curves showed a tendency of the gutta-percha/AH Plus root fillings to prevent leakage better than Resilon/Epiphany counterparts. This tendency, however, was not statistically significant (log-rank test, p = 0.141). The estimated mean time for turbidity to occur in the broth below the suspended root was 35 days (SD = 5 days) in the gutta-percha/AH Plus and 33 days (SD = 4 days) in the Resilon/Epiphany group. It was concluded that within the limitations of this study, there was no apparent advantage of using Resilon/Epiphany over gutta-percha/AH Plus.
Comparison of the Antimicrobial Efficacy of 1.3% NaOCl/BioPure MTAD to 5.25% NaOCl/15% EDTA for Root Canal Irrigation
J. Craig Baumgartner, Stephen Johal, DMD, J. Gordon Marshall, DMD
The purpose of this study was to compare the antimicrobial efficacy of 1.3% NaOCl/BioPure MTAD to 5.25% NaOCl/15% EDTA for root canal irrigation. Twenty-six bilaterally matched pairs of human teeth were collected. The teeth were incubated with Enterococcus faecalis for 4 weeks. The teeth were divided into two experimental groups and one positive control group. The canals were instrumented and irrigated with either 5.25% NaOCl/15% EDTA or 1.3% NaOCl/BioPure MTAD. Bacterial samples were collected after instrumentation/irrigation and after additional canal enlargement. Statistical analysis of the data using the Wilcoxon Signed Rank test showed significant differences between the experimental groups. The first bacterial samples revealed growth in 0 of 20 samples with 5.25% NaOCl/15% EDTA irrigation and in 8 of 20 samples with 1.3% NaOCl/BioPure MTAD irrigation. Samples taken after additional canal enlargement revealed growth in 0 of 20 samples in 5.25% NaOCl/15% EDTA and in 10 of 20 samples in 1.3% NaOCl/BioPure MTAD group. This investigation showed consistent disinfection of infected root canals with 5.25% NaOCl/15% EDTA. The combination of 1.3% NaOCl/BioPure MTAD left nearly 50% of the canals contaminated with E. faecalis.
The Effect of Operational Speed on the Fracture of Nickel-Titanium Rotary Instruments
G. Gray Kitchens Jr., DMD, MS, Frederick R. Liewehr, DDS, MS, Peter C. Moon, PhD
The purpose of this study was to compare the number of rotations to fracture of nickel-titanium (NiTi) rotary files operated at different speeds and different angles. We used 60 Profile NiTi rotary files, size 25 (30 each of 0.04 and 0.06 taper), operated at speeds of 350 or 600 rpm at angles of 25, 28, and 33.5 degrees. The time to fracture and number of rotations to fracture were recorded and calculated. A significant (p < 0.001) difference was found in the number of rotations to fracture according to taper and angle. Files of 0.06 taper fractured more readily than files of 0.04 taper. Increasing the angle at which the file was rotated decreased the number of rotations to fracture for both tapers; 0.04-taper files were more affected by an increase in the angle than the 0.06-taper files. However, the number of rotations to fracture was not related to the speed at which the files were operated.
Cyclic Fatigue of Protaper Instruments
Hélio Pereira Lopes, DDS, PhD, Edson Jorge Lima Moreira, DDS, MSc†, Carlos Nelson Elias, Eng, PhD, Renata Andriola de Almeida, Mônica Schultz Neves
The present work evaluated the influence of the curved segment length of artificial root canals (the arc) and the number of cycles necessary to fracture engine-driven nickel-titanium endodontic instruments. ProTaper F3 25-mm files at 250 rpm were used in two artificial canals. The artificial canals were made of stainless steel with an inner diameter of 1.04 mm, a total length of 20 mm, and arc on the ends with a radius of curvature of 6 mm. The arc length of the first tube measured 9.4 mm, and the straight part measured 10.6 mm. The second tube was 14.1 mm long, and the straight part measured 5.9 mm. We determined the fracture surface distances and the number of cycles necessary to induce fatigue fracture in the ProTaper F3 instruments. The fracture surfaces and the helical shaft of the instruments were investigated using a scanning electron microscope. The results indicated that the required number of cycles to cause a fracture was influenced by the canal arc length, the morphology of the fractured surface presented ductile characteristics, and plastic deformation in the helical shaft of the fractured instruments did not occur.
The Radix Entomolaris and Paramolaris: Clinical Approach in Endodontics
Filip L. Calberson, DDS, MMS, Roeland J. De Moor, DDS, MMS, PhD, Christophe A. Deroose, DDS, MMS
Mandibular molars can have an additional root located lingually (the radix entomolaris) or buccally (the radix paramolaris). If present, an awareness and understanding of this unusual root and its root canal morphology can contribute to the successful outcome of root canal treatment. This report discusses endodontic treatment of three mandibular molars with a radix entomolaris or paramolaris, both of which are rare macrostructures in the Caucasian population. The prevalence, the external morphological variations and internal anatomy of the radix entomolaris and paramolaris are described. Avoiding procedural errors during endodontic therapy demand an adapted clinical approach to diagnosis and root canal treatment.
Unusual Variant of Type 3 Dens Invaginatus in a Maxillary Canine: A Rare Case Report
Iztok Štamfelj, DMD, MSc, Andrej A. Kansky, DMD, PhD, Dominik Gašperšič, DMD, PhD
A 13-year-old boy presented with clinical symptoms of periapical inflammation related to the right maxillary canine. A bizarre radiographic appearance of the root was considered suggestive of a compound odontome. Histological examination of the surgically extracted canine revealed a very rare variant of Oehlers’ type 3 invagination. The invagination originated in a pit above the cingulum as a narrow coronal channel that opened into a large cavity inside the dilated root. The radicular part of the invagination contained all components of the attachment apparatus. The root canal and its apical foramen were slit-like and circular. Radiographic appearance of two roots separated by a wide interradicular area in a normally single-rooted tooth is indicative of this variant of type 3 invagination. Timely prophylactic treatment and follow-up or early endodontic treatment confined to the coronal channel are crucial to prevent pulp necrosis and consequent loss of the tooth.