Prion Disease: The Implications for Dentistry
Amir Azarpazhooh, DDS, MSc, FRCD(C), Edward D. Fillery, PhD
The aim of this article was to provide the dental community with a brief overview of the characteristics, risk of transmission, and the infection-control implications of prions in dentistry. MEDLINE, EMBASE, CINAHL, The Cochrane Library, and relevant databases were searched, and a targeted internet search was conducted up to July 2007. Transmissible spongiform encephalopathies (TSEs) are a group of fatal neurodegenerative diseases that are rapidly progressive and always fatal, with no approved cure, and their definite diagnosis can only be obtained at post mortem autopsy. The causative agent, prion protein, resists conventional sterilization methods especially when infected tissue becomes dried onto glass or metal surfaces. To date, there are no reported definite or suspected cases of disease transmission arising from dental procedures, and there seems to be no correlation between dental treatment and TSEs. Because there is a theoretical but real risk of transmission of prion disease from dental instruments (although it is extremely low, especially in North America), as a general rule, appropriate family and medical history (including the risk for prion diseases) should be obtained from all patients, before all dental procedures. TSE research regarding diagnosis, transmission, treatment, and inactivation of prions and other transmissible amyloidoses are ongoing, and, thus, dental professionals should maintain optimal and up-to-date standards of knowledge, infection control, and decontamination.
Effect of Sublingual Triazolam on the Success of Inferior Alveolar Nerve Block in Patients with Irreversible Pulpitis
Matthew Lindemann, DDS, MS, Al Reader, DDS, MS, John Nusstein, DDS, MS, Melissa Drum, DDS, MS, Mike Beck, DDS, MA
The purpose of this prospective, randomized, double-blind, placebo-controlled study was to determine the effect of the administration of sublingual triazolam on the success of the inferior alveolar nerve (IAN) block in patients experiencing irreversible pulpitis. Fifty-eight emergency patients diagnosed with irreversible pulpitis of a mandibular posterior tooth randomly received, in a double-blind manner, an identical sublingual tablet of either 0.25 mg of triazolam or a placebo 30 minutes before administration of a conventional IAN block. Access was begun 15 minutes after completion of the IAN block, and all patients had profound lip numbness. Success was defined as no or mild pain (visual analog scale recordings) on access or initial instrumentation. The success rate for the IAN block was 43% with triazolam and 57% with the placebo, with no significant difference (P = .43) between the 2 groups. For mandibular posterior teeth, triazolam in a sublingual dose of 0.25 mg did not result in an increase in success of the IAN block in patients with irreversible pulpitis. Therefore, when using conscious sedation, profound local anesthesia is still required to eliminate the sensation of pain during endodontic treatment for patients with irreversible pulpitis.
Retrospective Analysis of Open Apex Teeth Obturated with Mineral Trioxide Aggregate
David E. Witherspoon, BDSc, MS, Joel C. Small, DDS, John D. Regan, BDS, MS, Martha Nunn, DDS, PhD
This study is a retrospective analysis of the outcome of initial nonsurgical root canal treatment of teeth with open apices, obturated with mineral trioxide aggregate when no apical barrier existed. One hundred sixteen patients from a single private endodontic office were treated between 1999 and 2006. Treatments on 144 teeth were completed either in one (92/144) or two visits with an interim calcium hydroxide interappointment medication (52/144). Fifty-four percent (78/144) of the teeth were available for recall (60.3% one visit and 39.7% two visits). The maximum time to recall was 4.87 years. The mean time to recall was 19.4 months. Of the cases recalled for period of 1 year or longer, 93.5% of teeth treated in 1 visit healed, and 90.5% of teeth treated in 2 visits healed.
Flare-ups after Endodontic Treatment: A Meta-analysis of Literature
Igor Tsesis, DMD, Vadim Faivishevsky, DMD, Zvi Fuss, DMD, Ofer Zukerman, DMD
The purpose of this study was to determine the frequency of flare-ups and to evaluate factors that affect it by using meta-analysis of results of previous studies. MEDLINE database was searched by using Entrez PubMed search engine and Medical Subject Headings (MeSH) search with EviDents Search Engine to identify the studies dealing with endodontic flare-up phenomenon. The search covered all articles published in dental journals in English from 1966–May 2007, and the relevancy of 119 selected articles was evaluated by reading their titles and abstracts, from which 54 were rejected as irrelevant and 65 were subjected to a suitability test. Six studies that met all the above mentioned criteria were included in the study. Average percentage of incidence of flare-ups for 982 patients was 8.4 (standard deviation ±57). There were insufficient data to investigate the effect of the influencing factors.
Anatomic Determination of the Mesiobuccal Root Resection Level in Maxillary Molars
Randy Degerness, DDS, MS, Walter Bowles, DDS, MS, BPharm
Surgical endodontics involving root resection/apical fill are often performed when retreatment by orthograde endodontic procedures are not possible. Because of the potential presence of accessory canals within the root, a preferred minimal root resection level should be investigated for the removal of the majority of these canals. One hundred fifty-three extracted, uninstrumented, mesiobuccal roots from first and second maxillary molars were examined for the presence of accessory canals, canal isthmus, and canal wall thickness. Three hundred ninety accessory canals were identified, with 80% of these canals located within 3.64 mm of the apex of the tooth. Canal isthmus was often not evident until 3.12 mm of the root was resected, with canal wall thickness only approximating 1 mm thick. The observations here suggest a minimal resection level to 3.6 mm for accessory canal incidence, canal isthmus detection, and canal wall thickness and provide a better understanding of maxillary mesiobuccal (MB) root anatomy for retrograde root resection/apical filling.
Identification of a C-shaped Canal System in Mandibular Second Molars—Part III: Anatomic Features Revealed by Digital Subtraction Radiography
Wei Fan, DDS, MSc, PhD, Bing Fan, DDS, MSc, PhD, James L. Gutmann, DDS, PhD, FACD, FICD, FADI, Mingwen Fan, DDS
The purpose of this study was to investigate the ability of digital subtraction radiography (DSR) to reveal anatomic features of C-shaped canal systems in mandibular second molars with the aid of an intraradicular contrast medium. Thirty mandibular second molars with fused roots were collected and stored in 10% formalin solution. After being scanned with microcomputed tomography (μCT) 20 and reconstructed, the root canals were mechanically and chemically cleaned of their pulp tissue. Buccal-lingual digital radiographic (radiovisiography [RVG]) images were taken with mandibular bone plates for each tooth. After the introduction of contrast medium into canals, RVG images were taken again in the same way as before. The digital images taken before and after contrast medium introduction were overlapped, and the image subtraction was performed by using the 3D Doctor software (Able Software Corp, Lexington, MA). All the subtracted canal images (DSR) and reconstructed canal images based on μCT scanning were classified into three categories (ie, type I, II, and III). The classifications based on reconstructed canal images were used as the standard to evaluate the sensitivity (Se) and specificity (Sp) of DSR classification. The results were subjected to the Wilcoxon statistical test, which showed there was no significant difference between the two classifications (p > 0.05). The DSR classification had a very high Se and Sp in all three categories. It is feasible to use the DSR technique clinically to identify anatomic features of the C-shaped canal system in mandibular second molars.
Mechanisms of N-acetyl Cysteine–mediated Protection From 2-Hydroxyethyl Methacrylate–induced Apoptosis
Avina Paranjpe, DDS, MS, PhD, Nicholas A. Cacalano, PhD, Wyatt R. Hume, DDS, PhD, Anahid Jewett, PhD, MPH
Resin-based materials are now commonly used in dentistry in restorative materials as well as in endodontic sealers. These materials have been shown to be cytotoxic. The mechanisms by which resin-based materials mediate their adverse effects have not been completely elucidated. Here we show that 2-hydroxyethyl methacrylate (HEMA) induces apoptotic cell death in oral keratinocytes and immune cells through the intrinsic cell death pathway. Functional loss and cell death induced by HEMA was significantly inhibited in the presence of N-acetyl cysteine (NAC) treatment. In addition, HEMA induced a decrease in mitochondrial membrane potential, and an increase in cleaved caspases was potently inhibited in the presence of NAC treatment. Overall, the results reported in this article indicate that NAC is an effective chemoprotectant that can safely be used to protect the pulp and the surrounding tissues from adverse effects of dental restorative and endodontic materials.
Confocal Laser Scanning Microscopy Is Appropriate to Detect Viability of Enterococcus faecalis in Infected Dentin
Ronald Ordinola Zapata, DDS, Clovis M. Bramante, DDS, PhD, Ivaldo Gomes de Moraes, DDS, PhD, Norberti Bernardineli, DDS, PhD, Thais Helena Gasparoto, DDS, Marcia S.Z. Graeff, MS, Ana Paula Campanelli, PhD, Roberto Brandão Garcia, DDS, PhD
The purpose of this study was to explore the potential of confocal laser scanning microscopy (CLSM) for in situ identification of live and dead Enterococcus faecalis in infected dentin. Eight cylindrical dentin specimens were infected with Enterococcus faecalis in BHI for 21 days. After the experimental period, the specimens were stained with fluorescein diacetate (FDA) and propidium iodide (PI) or acridine orange (0.01%) and analyzed by CLSM. Two noninfected dentin specimens were used as negative controls. CLSM analysis shows that the discrimination between viable (green) and dead (red) bacteria in infected dentinal tubules could be observed after staining with FDA/PI. Acridine orange was able to show metabolic activity of the E. faecalis cells inside the dentinal tubules showed by its red fluorescence. The viability of bacteria in infected dentin can be determined in situ by CLSM. FDA/PI and acridine orange are useful for this technique.
Vasorelaxant Effect of a Self-etch Adhesive System through Calcium Antagonistic Action
Feridun Basak, DDS, PhD, Ismail Mert Vural, MD, PhD, Ertugrul Kaya, MD, PhD, Cunay Ulku, MD, PhD, Gunseli Guven, DDS, PhD, S. Burcak Cehreli, DDS, PhD, Zafer C. Cehreli, DDS, PhD, Melik Seyrek, MD, PhD, Oguzhan Yildiz, MD, PhD
Etch-and-rinse adhesives can cause vasorelaxation via mechanisms occurring in the endothelium and smooth muscle, including the release of nitric oxide (NO). This effect might promote or aggravate bleeding if such adhesives are placed inadvertently on iatrogenic pulp microexposures. The present study assessed the vasoactive potential of a newer generation self-etch adhesive, Clearfil Protect Bond (CPB), on isolated rat aorta. Cumulative concentrations of the primer, bond, and mixture of CPB elicited concentration-dependent relaxation of phenylephrine-induced active tonus in the rat aorta, demonstrating that the tested self-etch adhesive can lead to vasorelaxation of pulp vessels that is mediated by Ca2+ antagonistic effect. The vasorelaxant effect of CPB or its components was mediated neither via endothelium-dependent NO and prostanoid-dependent mechanisms nor by K+ efflux through K+ channels. Mechanical removal of the endothelium did not significantly alter the relaxation induced by CPB. Assuming these data can be extrapolated to the clinical situation, CPB, either in mixed form or by its components, can lead to vasorelaxation of pulp vessels that is mediated by a Ca2+ antagonistic effect. If CPB is placed inadvertently on pulp microexposures during direct pulp capping, this effect might promote bleeding that might impair healing and, via plasma exatravasation, might compromise resin infiltration and polymerization.
Activation of p38 Mitogen-activated Protein Kinase in Rat Periapical Lesions
Rui Zhang, DDS, Li Wang, DDS, Bin Peng, DDS, PhD
The purpose of this study was to investigate the activation of p38 mitogen-activated protein kinase (MAPK) during the development of periapical lesions in rats. Periapical lesions developed within 28 days after pulp exposure of mandibular first molars in Wistar rats. The animals were sacrificed randomly at 0, 7, 14, 21, and 28 days after pulpal exposure. The jaws that contained the first molar were obtained and routinely prepared for immunohistochemistry and enzyme histochemistry. A few phosphorylated p38 MAPK (P-p38)-positive cells and osteoclasts could be observed on day 7; both peaked in number on day 14. In the 21- and 28-day samples, the P-p38 MAPK expression decreased and fewer osteoclasts were observed. From day 7 to day 28, a significant positive correlation was found between P-p38 MAPK expression and osteoclasts. These findings showed that the activation of p38 MAPK might be associated with bone resorption in periapical lesions.
Diabetes Induces Metabolic Alterations in Dental Pulp
Mariana Ferreira Leite, DDS, PhD, Emily Ganzerla, DDS, PhD, Márcia Martins Marques, DDS, PhD, José Nicolau, DDS, PhD
Diabetes can interfere in tissue nutrition and can impair dental pulp metabolism. This disease causes oxidative stress in cells and tissues. However, little is known about the antioxidant system in the dental pulp of diabetics. Thus, it would be of importance to study this system in this tissue in order to verify possible alterations indicative of oxidative stress. The aim of this study was to evaluate some parameters of antioxidant system of the dental pulp of healthy (n = 8) and diabetic rats (n = 8). Diabetes was induced by streptozotocin in rats. Six weeks after diabetes induction, a pool of the dental pulp of the 4 incisors of each rat (healthy and diabetic) was used for the determination of total protein and sialic acid concentrations and catalase and peroxidase activities. Data were compared by a Student t test (p ≤ 0.05). Dental pulps from both groups presented similar total protein concentrations and peroxidase activity. Dental pulps of diabetic rats exhibited significantly lower free, conjugated, and total sialic acid concentrations than those of control tissues. Catalase activity in diabetic dental pulps was significantly enhanced in comparison with that of control pulps. The result of the present study is indicative of oxidative stress in the dental pulp caused by diabetes. The increase of catalase activity and the reduction of sialic acid could be resultant of reactive oxygen species production.
The Effect of a Resin-based Sealer Cement on Micropunch Shear Strength of Dentin
Angsana Jainaen, DDS, Cert (Endodontology), PhD, Joseph E.A. Palamara, PhD, Harold H. Messer, MDSc, PhD
Dentinal tubules occupy a substantial proportion of total dentin volume, especially of inner dentin. Resin-based sealer cements are known to penetrate deeply into dentinal tubules, but their ability to influence root strength is controversial. In this study, the contribution of dentinal tubules to shear strength and the influence of a resin-based sealer on shear strength were evaluated. Coronal 100-μm sections of 12 single-canal premolar teeth were tested in different locations (buccal and proximal) and tubule directions (parallel and perpendicular) using the micropunch shear test (MPSS). Tests were also conducted by using 10 two-canal premolars, with one untreated canal and the other obturated using epoxy resin-based sealer (plus gutta-percha). No difference in MPSS was found because of location or tubule orientation (p > 0.05). Outer dentin had a higher MPSS than middle and inner dentin (p < 0.001). Tubule infiltration by epoxy resin did not increase MPSS.
Comparison of Effects of ProTaper, HeroShaper, and Gates Glidden Burs on Cervical Dentin Thickness and Root Canal Volume by Using Multislice Computed Tomography
Abeer H. Mahran, BDS, MSc, PhD, Mona M. AboEl-Fotouh, BDS, MSc, PhD
The purpose of this study was to compare the effects of 3 different instruments used to prepare curved root canals on the remaining cervical dentin thickness and total amount of dentin removed from root canals during instrumentation by using multislice computed tomography. Mesiobuccal canals of 45 mandibular first molars with curvature between 30–40 degrees were divided into 3 equal groups: ProTaper, Hero Shaper, and Gates Glidden Bur with Flex-R hand file. Cervical dentin thickness and canal volume were measured before and after instrumentation by using multislice computed tomography and image analysis software. The results indicated that ProTaper removed significantly less cervical dentin from distal wall of the root (dangerous zone) than HeroShaper and Gates Glidden Bur (P < .05). The total dentin removed during canal instrumentation was significantly more with ProTaper system (P < .05).
Efficacy of ProTaper Retreatment System in Root Canals Filled with Gutta-Percha and Two Endodontic Sealers
Marcus Vinícius Reis Só, DDS, MSc, PhD, Caroline Saran, DDS, Miriam Lago Magro, DDS, MSc, Fabiana Vieira Vier-Pelisser, DDS, MSc, PhD, Marcelo Munhoz, DDS
This study evaluated the efficacy of ProTaper Universal rotary retreatment system and hand files for filling material removal during retreatment and the influence of sealer type on the presence of filling debris in the reinstrumented canals. The canals of 60 palatal roots of first molars were obturated with gutta-percha and either a zinc oxide–eugenol–based or a resin-based sealer and reinstrumented: G1, EndoFill/hand files; G2, AH Plus/hand files; G3, EndoFill/ProTaper; G4, AH Plus/ProTaper. Roots were cleaved and examined with an optical microscope, and the amount of filling debris on canal walls was analyzed on digitized images. There was no significant difference (P > .05) among the root canal thirds within each group. G3 presented significantly more filling debris than G1 in the cervical third (P = .04). In the middle third, G2/G3/G4 showed more debris than G1 (P = .03). The techniques were similar (P = .64) in the apical third. All groups presented filling debris in the 3 canal thirds after reinstrumentation.
Effect of pH on Sealing Ability of White Mineral Trioxide Aggregate as a Root-end Filling Material
Mohammad Ali Saghiri, BSc, MSc, PhD student, Mehrdad Lotfi, DMD, MSc, Ali Mohammad Saghiri, Sepideh Vosoughhosseini, DMD, MSc, Ali Fatemi, DMD, Vahab Shiezadeh, DMD, Bahram Ranjkesh, DMD
The aim of the present study was to evaluate microleakage of mineral trioxide aggregate (MTA) used as a root-end filling material after its exposure to a range of acidic environments during hydration. Seventy single-rooted teeth were divided into 4 experimental and 2 control groups. All the teeth were instrumented, and their apices were resected. Root-end cavities were filled with white MTA in the experimental groups. In the control groups root-end cavities were not filled. Root-end fillings were exposed to acidic environments with pH values of 4.4, 5.4, 6.4, or 7.4 for 3 days in the experimental groups. Microleakage was evaluated by using bovine serum albumin. The evaluation was conducted at 24-hour intervals for 80 days. Data were analyzed by using one-way analysis of variance and a post hoc Tukey test. The earliest bovine serum albumin microleakage was observed in a pH value of 4.4 followed by pH values of 5.4, 6.4, and 7.4, respectively. There was a significantly longer time necessary for leakage to occur in samples stored in higher pH values (P < .000).
Effects of Different Light-curing Units and Obturation Techniques on the Seal of the Resilon/Epiphany System
Emre Nagas, DDS, M. Ozgur Uyanik, DDS, PhD, Cem Sahin, DDS, PhD, Veli Durmaz, DDS, PhD, Zafer C. Cehreli, DDS, PhD
The purpose of this study was to compare the sealing ability of a resin- and polymer-based root canal obturation system (Resilon; Resilon Research LLC, Madison, CT/Epiphany; Clinical Technologies, Wallingford, CT) used in conjunction with different light-curing units and obturation techniques. A total of 120 decrowned single-rooted human teeth were used. After preparation of the root canals with 0.06 taper nickel-titanium rotary files to size 30, the roots were randomly assigned into three experimental groups according to the obturation technique used: (1) single cone, (2) cold lateral compaction, and (3) System B + Obtura. In all groups, the specimens were randomly assigned into four subgroups according to the polymerization method that was used to cure Epiphany sealer from the coronal aspect: (1) quartz-tungsten-halogen (QTH), (2) light-emitting diode (LED), (3) plasma-arc curing (PAC), and (4) chemical cure (uncured). Leakage was measured by the fluid-filtration method at 1 day and 1 week. Statistical analysis was performed by using Kruskal-Wallis and Wilcoxon signed-rank tests at p < 0.001. Fluid conductance of all groups increased significantly within time (p < 0.001). The tested obturation techniques had no significant effect on the leakage values (p = 0.433). The following statistical ranking was obtained for fluid-filtration values: uncured > PAC > LED > QTH (p < 0.001).
Evaluation of a Rotary Instrumentation Method for C-shaped Canals with Micro-computed Tomography
Lisa H.M. Cheung, BDS, MDS, AdvDipEndodnt, Gary S.P. Cheung, BDS, MDS, MSc, PhD
This study aimed to evaluate the safety and efficacy of a method of using nickel-titanium rotary instruments for preparing the C-shaped root canal system. Forty-three human mandibular second molars with a C-shaped canal configuration were prepared with a crown-down approach to an apical dimension of size 30 by using a combination of ProFile and HERO instruments. Micro–computed tomography was used to examine the canal diameter and the remaining thickness of the dentin wall along the root canal. Results showed that only isolated regions in cross section of the C-shaped canal were physically prepared by the rotary instruments. The furcal wall (concave aspect of the “C” in cross section) of all clinically identifiable canals had a similar thickness at a distance 1–7 mm from the apical constriction both before and after instrumentation. More dentin was removed from the outer (convex aspect of the “C”) than the furcal aspect at the apical region, but the converse was true more coronally. All prepared canals showed a taper that matched that of the last instrument used. It was concluded that cleaning of the C-shaped canal system is incomplete with the use of rotary instruments and should be assisted by ultrasonic irrigation. Although rotary instruments seemed to be safe in such canals, further enlargement to an apical dimension greater than size 30 (0.06 taper) is not recommended.
Ex Vivo Study of the Efficiency of Two Techniques for the Removal of Mineral Trioxide Aggregate Used as a Root Canal Filling Material
Christos Boutsioukis, DDS, MSc, Giovana Noula, DDS, Theodor Lambrianidis, DDS, PhD
The purpose of this study was to evaluate the removal efficiency of mineral trioxide aggregate (MTA) used as a root filling material. Ninety-three human teeth prepared with a step-back technique were randomly assigned to 2 groups and filled with vertically compacted MTA (group A) or MTA and a gutta-percha cone (group B). Fillings were removed by using ultrasonics and/or rotary nickel-titanium instruments. Roots were split into halves, and a 1 to 4 scoring system was used to assess the amount of residue. Data were analyzed with Kruskal-Wallis and Mann-Whitney tests. Remnants were found in all specimens. Rotary instruments were unable to penetrate canals in group A. The combination of rotary instruments and ultrasonics was superior in group B. Dark discoloration of most MTA fillings was evident. The results suggest that MTA cannot be completely removed from the root canal system by any of the methods examined.
A Scanning Electron Microscopic Evaluation of the Effectiveness of the F-file versus Ultrasonic Activation of a K-file to Remove Smear Layer
Sonia Chopra, DDS, Peter E. Murray, PhD, Kenneth N. Namerow, DDS
The objective of this study was to compare the effectiveness of F-files and ultrasonics to remove the smear layer from instrumented root canals when irrigated with sodium hypochlorite and EDTA. Sixty healthy human premolar teeth were instrumented with ProTaper file series to F3, and the canals were enlarged with Profiles 35/.06, 40/.06, and 45/.06. The canals were then instrumented with either the F-file or an ultrasonically activated #20 K-file with or without EDTA. The removal of smear layer was visualized using blind scanning electron microscopic micrographs. There appeared to be little difference between the F-file and the ultrasonically activated #20 K-file in removal of the smear layer with or without EDTA. The effect of ultrasonic activation appeared to be self-limiting with high-volume flushes of irrigant. It appears the F-file was not any more beneficial in removing smear layer. Conversely, smear layer removal appears to be mostly influenced by the introduction of an EDTA rinse.
An Agar Diffusion Comparison of the Antimicrobial Effect of Calcium Hydroxide at Five Different Concentrations with Three Different Vehicles
Michael L. Blanscet, DDS, MS, Patricia A. Tordik, DMD, Gary G. Goodell, DDS, MS, MA
The purpose of this study was to determine if varying the percent (by weight) of aqueous calcium hydroxide or using different vehicles had an effect on its antibacterial efficacy against common endodontic pathogens in a pour plate/traditional streak agar diffusion model. Mixtures of calcium hydroxide powder and sterile saline in 40, 50 and 60 percent concentrations and the commercial preparations UltraCal XS and Vitapex were tested against six known endodontic pathogens with an agar diffusion method. Each medicament was placed in one of five wells, in each of 10 agar plates (n = 10), for cultures of each bacterial species. Zones of inhibition were measured after 48 hours incubation for aerobes and 96 hours incubation for anaerobes. Multiple one-way analyses of variance and post-hoc Student Neuman Keuls evaluated the data at α = 0.05. Larger zones of inhibition were consistently observed for higher concentrations of calcium hydroxide with statistical significance among the bacteria, particularly between 40% and 60%. Vitapex had significantly smaller zones of inhibition than all other medicaments and 35% Ultracal XS with methylcellulose was nearly as effective as 50% Ca(OH)2 in inhibitory activity. Formulations containing 50–60% Ca(OH)2 or 35% Ca(OH)2 with aqueous methylcellulose are recommended as endodontic interappointment medicaments.
Anatomic and Microbiologic Challenges to Achieving Success with Endodontic Treatment: A Case Report
Domenico Ricucci, MD, DDS, José F. Siqueira Jr, DDS, MSc, PhD
This article describes a case of persistent apical periodontitis that required several nonsurgical and surgical approaches for resolution. A 28-year-old woman presented with a large symptomatic apical periodontitis lesion associated with the maxillary left lateral incisor that persisted in spite of previous nonsurgical and surgical endodontic treatment. Root canal retreatment was accomplished, but the lesion only showed a slight decrease in size after 18 months. Forty-six months after retreatment, the patient returned because of reemergence of symptoms. Radiographically, the lesion remained relatively unaltered. Periradicular resurgery was performed, and a biopsy specimen consisting of the lesion and the apical part of the root was collected for analysis. Radiographic and clinical reevaluation after 4 years revealed complete healing. Histopathologic and histobacteriologic observations demonstrated that the lesion was a cyst, and that the probable reason for failure was the occurrence of bacteria within dentinal tubules and in a lateral canal slightly coronal to the amalgam root-end filling. This case report clearly illustrates the difficulties imposed by anatomic complexities in attaining a disinfection level that is compatible with periradicular tissue healing.
Combined Endodontic and Surgical Management of a Mandibular Lateral Incisor with a Rare Type of Dens Invaginatus
Antonios M. Chaniotis, DDS, MSc, Giorgos N. Tzanetakis, DDS, MSc, Evangelos G. Kontakiotis, DDS, PhD, Konstantinos I. Tosios, DDS, MSc, PhD
Dens invaginatus is a developmental malformation of teeth that most commonly affects permanent maxillary lateral incisors. Presence of dens invaginatus in mandibular permanent teeth is relatively rare. The purpose of this report is to describe the combined nonsurgical and surgical management of a mandibular lateral incisor associated with a rare type of dens invaginatus. Pulp involvement of the malformed tooth, periapical abscess, and severe periodontal destruction were observed. The signs (sinus tracts) and symptoms ceased after completion of the treatment. Satisfactory healing of the periradicular lesion was observed at the 6-month and 2-year follow-up examinations.
Rapid Periapical Bone Destruction During Endodontic Treatment of a Patient with Rheumatoid Arthritis
Won-Mann Oh, DDS, PhD, In-Nam Hwang, DDS, PhD, Ho-Hyun Son, DDS, PhD, Yun-Chan Hwang, DDS, PhD
Rheumatoid arthritis is an autoimmune disease with an unknown etiology. Azathioprine is an immunosuppressive drug that is used to treat rheumatoid arthritis. This case report describes the rapid periapical bone destruction that occurred during the endodontic treatment of a rheumatoid arthritis patient taking azathioprine and a corticosteroid. The cause of the rapid destruction is unclear. However, severe side effects can occur after administering azathioprine to rheumatoid arthritis patients. Therefore, dentists should check the patient's medical state thoroughly in order to prevent side effects when performing endodontic treatment.