Infection in a Complex Network of Apical Ramifications as the Cause of Persistent Apical Periodontitis: A Case Report

Introduction

This article reports a case of persistent apical periodontitis lesion in a mesiobuccal root of a maxillary molar subjected to single-visit endodontic treatment.

Methods

The treatment protocol followed endodontic standards including using nickel-titanium instruments with working length ending 0.5-mm short of the apex, establishment and maintenance of apical foramen patency, irrigation with 5% NaOCl, smear layer removal, a final rinse with and ultrasonic agitation of chlorhexidine, and filling by the vertical compaction technique. Even so, the lesion in the mesiobuccal root became larger in size after follow-up examination at 1 year 6 months, and periradicular surgery was performed. Radiographic control after 11 months showed that periradicular healing was almost complete. The root apex and the lesion were analyzed histologically and histobacteriologically.

Results

The lesion was diagnosed as a “pocket cyst,” and no bacteria were noted extraradicularly. The cause of continued disease was a heavy bacterial biofilm infection located in an intricate network of apical ramifications. Bacteria were also observed on the walls of one of the mesiobuccal canals packed between the obturation material and the root canal wall.

Conclusions

This case report reinforces the need for treating the infected root canal as a complex system that possesses anatomic intricacies in which bacteria can spread and remain unaffected by treatment procedures.     

Endodontic Microbial Communities in Apical Periodontitis

IntroductionApical periodontitis (AP) represents an inflammatory condition of peri-radicular tissues due to invasion and colonization of bacteria in the root canals. Primary apical periodontitis (PAP) is associated with untreated necrotic root canal and can be efficiently treated with endodontic treatment to remove bacteria. Persistent/secondary apical periodontitis (SAP) is a perpetual periapical lesion due to unsuccessfully treated root canals after an initial apparent healing of the tooth. The aim of the study was evaluating the microbial communities associated with root canals using Nanopore sequencing.MethodsSeventeen samples from the root canals of 15 patients with AP were Polymerase Chain Reaction-amplified for 16s ribosomal DNA gene and sequenced. Information regarding the presence or absence of AP symptoms, PAP and SAP, and periapical index of patients were recorded.ResultsFirmicutes, Bacteroidetes, and Actinobacteria were the most abundant phyla detected and Phocaeicola, Pseudomonas, Rothia, and Prevotella were the most prominent genera. In samples of patients with AP symptoms, the most frequent detected genera were Cutibacterium, Lactobacillus, Pseudomonas, Dialister, Prevotella, and Staphylococcus. In PAP samples, the most represented genera were Cutibacterium, Lactobacillus, Pseudomonas, and Prevotella, whilst in SAP cases were Cutibacterium, Prevotella, Atopobium, Capnocytophaga, Fusobacterium, Pseudomonas, Solobacterium, and Streptococcus.ConclusionsThe results provide additional information on the microbiota of root-canals. These data evidence the complexity of the microbiota and the relationship with many clinical and endodontic conditions. Future studies must evaluate these conditions and identify their role in inducing bone damage and local and systemic disease, aiming to better elucidate the relationship between microbes and endodontic pathologies.     

Apical Periodontitis,a Predictor Variable for Preeclampsia: A Case-control Study

Introduction

Preeclampsia (PE) is characterized by hypertension and proteinuria after the 20th week of gestation. There is an association between systemic inflammation and adverse pregnancy outcomes such as PE. Therefore, for the first time, the present study aimed to investigate the possible association between maternal apical periodontitis (AP) and PE.

A Survey of Dentists' Preferences for the Treatment of Teeth with Apical Periodontitis

Introduction

This study surveyed the preferences of Ontario, Canada dentists for teeth with apical periodontitis when selecting between retention via root canal treatment (RCT) and extraction without replacement, or replacement with implant-supported crowns (ISC), fixed, or removable partial prostheses.

Methods

A mail-out survey (census of Ontario endodontists, periodontists, prosthodontists, and oral and maxillofacial surgeons; n = 498, 40% response rate) and a Web-based survey (sample of Ontario general dentists; n = 1983, 15% response rate) were conducted. Participants ranked their treatment preferences for 4 clinical scenarios: an anterior or posterior tooth, without or with previous RCT. Associations between treatment preferences and covariates were explored by using bivariate and logistic regression analyses (P ≤ .05).

Results

For all 4 scenarios, the majority of participants preferred either RCT or ISC, whereas other treatment options were preferred by ≤3.1% of the participants in any professional registration category. A pattern of declining preference for RCT and increasing preference for ISC was noted across the scenarios, with significantly lower preference for RCT and higher preference for ISC associated with teeth needing repeated RCT compared with initial RCT (odds ratio [OR] = 3.3; confidence interval [CI], 2.5–4.4). Preferences were significantly lower for RCT and higher for ISC among general dentists (OR = 6.4; CI, 2.3–17.6), prosthodontists (OR = 9.1; CI, 3.0–28.3), periodontists (OR = 18.3; CI, 6.4–51.6), and surgeons (OR = 30.1; CI, 10.8–86.6) when compared with endodontists.

Conclusions

More surveyed dentists preferred RCT than ISC for teeth with apical periodontitis requiring initial RCT than repeated RCT. The dentists' preferences were associated with their professional registration but not with other characteristics.     

Healing of Apical Periodontitis after Nonsurgical Root Canal Treatment: The Role of Statin Intake

Introduction

Numerous previously undocumented factors may influence the healing of apical periodontitis (AP). The aim of this cohort study was to analyze the association between statin medication intake during the follow-up period and healing of AP.

Omega-3 Fatty Acids Reduce Inflammation in Rat Apical Periodontitis

Introduction

The effects of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) on pro- and anti-inflammatory mediators were evaluated in a rat model of pulp exposure–induced apical periodontitis (AP).

Recurrent Apical Periodontitis and Late Endodontic Treatment Failure Related to Coronal Leakage: A Case Report

Introduction

This article describes a case of late failure after endodontic retreatment as characterized by recurrent post-treatment apical periodontitis.

Methods

At the time of the initial treatment, the patient presented with acute apical abscess associated with a tooth with pulp necrosis caused by trauma. Four years later, the tooth was retreated because of persistent disease. The follow-up examination 28 months after retreatment showed complete healing.

Results

The patient returned 11 years and 7 months later for bleaching of the discolored tooth, and although the periodontal tissues were clinically and radiographically normal, a fracture line was observed on the mesial aspect of the pulp chamber. Extraction was indicated, but the patient only returned 5 years and 9 months later. Then a radiograph showed recurrent post-treatment apical periodontitis. The tooth was extracted, and histopathologic and histobacteriologic analyses revealed bacterial colonies along the fracture line and colonizing ramifications and accessory canals at the apical root canal system.

Conclusions

Coronal leakage can be regarded as the most reasonable explanation for resurgence of the disease. However, a predisposing overlapping condition in the form of root fracture conceivably favored the penetration of bacteria from saliva and plaque biofilm along the filled root canal.     

Repair of Extensive Apical Root Resorption Associated with Apical Periodontitis: Radiographic and Histologic Observations after 25 Years

Introduction

Root resorption is a frequent finding in teeth with apical periodontitis. In cases of severe apical periodontitis, root resorption may involve not only cementum but also dentin. Resorbed tooth structures can only be repaired with cementum because stem cells in the periradicular tissues are not capable of differentiating into odontoblasts. This article reports the repair of extensive apical root resorption associated with apical periodontitis 25 years after treatment.

Methods

A 51-year-old man presented with pulp necrosis and symptomatic apical periodontitis in tooth #7. The periapical radiograph showed a large radiolucent periradicular lesion and severe root resorption. Nonsurgical root canal therapy was performed. Twenty-five years after treatment, a crown fracture developed, and the tooth could not be restored. The periapical radiograph revealed complete healing of the previous apical periodontitis lesion and restoration of the resorbed root structure. The tooth was removed and examined histologically.

Results

The apical canal was almost completely filled with a cementumlike tissue with some strands of entrapped vital uninflamed connective tissue. Areas of cementum and dentin resorption in the apical third were repaired by a combination of cellular and acellular cementum to which periodontal ligament fibers were attached.

Conclusions

Root resorption caused by apical periodontitis can be restored almost to its normal structure after adequate nonsurgical root canal treatment that succeeded in controlling infection. The mechanisms behind this process are not clear but probably involve signaling pathways regulating root development, cell-cell and cell-matrix interaction, and morphogens.     

Large Bacterial Floc Causing an Independent Extraradicular Infection and Posttreatment Apical Periodontitis: A Case Report

This article describes a case of large persistent posttreatment apical periodontitis associated with 2 maxillary incisors, which was successfully managed by periradicular surgery. Histobacteriologic analysis revealed that the lesion was a granuloma that contained in its body a very large actinomycoticlike colony surrounded by accumulations of polymorphonuclear leukocytes and showing no direct communication with the root canal systems from both teeth. One incisor had no evidence of persistent intraradicular infection, whereas the other exhibited some residual dentinal tubule infection in the apical canal, which may have not significantly contributed to persistent inflammation given the organization and agglomeration of inflammatory cells around the large extraradicular bacterial colony. Findings showed that the main cause of persistent disease was the extraradicular infection in the form of a large bacterial floc, apparently independent of an intraradicular infection and as such only solved by surgery.     

An Overview on Biologic Medications and Their Possible Role in Apical Periodontitis

Introduction

Apical periodontitis (AP) is the expression of a deficient balance between infection and the host immune response.

Methods

If reducing the bacterial load from the root canal and preventing its reinfection may lead to clinical success, then the integrity of the nonspecific immune system has a relevant influence on the outcome of endodontic treatment.

Results

Compromised immune systems and/or genetic alterations of the host's response may as well play an important role on the development, progression, and healing of AP. Thus, immunomodulatory drugs might have the potential to influence both the severity of AP and the outcome of endodontic treatment. Biologic medications are a new class of drugs of monoclonal antibodies or fusion proteins that include fragments of a peculiar cytokine receptor. Specific inflammatory molecules or cells, such as tumor necrosis factor, interleukins, and T or B cells, are the selective targets of these drugs. They modulate the altered immune response and perform an important role in the short-term treatment of chronic inflammatory diseases such as rheumatoid arthritis, refractory Crohn disease, or ulcerative colitis. Despite the clinical positive outcomes and their widespread use, the consequences of administering biologic medications on the development of the dental diseases have not been adequately investigated.

Conclusions

The aim of this review was to give an overview of biologic medications, their composition, their mechanisms of action, and their possible implications on endodontic and other dental diseases.     

The Apical Root Canal System of Teeth with Posttreatment Apical Periodontitis: Correlating Microbiologic,Tomographic, and Histopathologic Findings

IntroductionThis study evaluated the microbiological conditions of the apical root canal system of teeth with posttreatment apical periodontitis and correlated them with observations from cone-beam computed tomographic (CBCT) imaging, micro–computed tomographic (micro-CT) imaging, and histopathology.MethodsRoot apices were obtained from 36 root canal–treated teeth subjected to periradicular surgery. CBCT examination was available before surgery. The apical root specimens were scanned in a micro-CT device and then cryopulverized. The powder was subjected to DNA extraction for real-time polymerase chain reaction quantification of total bacteria, Streptococcus species, members of the phylum Actinobacteria, and Enterococcus faecalis. Microbiological findings were evaluated for associations with CBCT, micro-CT, and histopathologic data. An association between lesion size and the proportion of unfilled apical canal system volume was also assessed.ResultsAll cryopulverized specimens were positive for total bacteria. Actinobacteria and streptococci occurred in 35 and 33 specimens, respectively, and were usually dominant in the community. Actinobacteria counts were 2.23 times higher in granulomas than in cysts. Streptococci were significantly more present in small lesion cases. E. faecalis was detected in only 7 samples, always as a dominant community member. The association of total bacteria, streptococci, and Actinobacteria counts with the unfilled canal volume was significant in the univariate analyses but not confirmed in the adjusted analyses. Large lesions were significantly associated with a higher volume of unfilled apical canals.ConclusionsBacterial infection occurred in all root apices, with high prevalence and dominance of Actinobacteria and streptococci. The volume of the unfilled apical canal system was significantly associated with the lesion size and possibly with bacterial counts. Findings illustrate the need to thoroughly disinfect and fill the apical root canal of infected teeth during endodontic therapy.     

Omega-3 Fatty Acids Alter Systemic Inflammatory Mediators Caused by Apical Periodontitis

IntroductionThis study investigated the effects of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) on serum inflammatory mediators of rats with pulp exposure–induced apical periodontitis.MethodsForty male Wistar rats were divided into the following groups: control, untreated rats (C); control rats treated with ω-3 PUFAs (C-O); rats with pulp exposure–induced apical periodontitis (AP); and rats with pulp exposure–induced apical periodontitis treated with ω-3 PUFAs (AP-O). ω-3 PUFAs were administered orally once a day for 15 days before pulp exposure and continued for 30 days after pulp exposure. The rats were sacrificed, and then blood and jaw samples were collected. Blood analysis was conducted to determine the total number of leukocytes including neutrophils, monocytes, and lymphocytes. Proinflammatory cytokines tumor necrosis factor alpha, interleukin (IL) 6, and IL-17 were quantified by enzyme-linked immunosorbent assay. Histologic analysis was performed to confirm the development of apical periodontitis. The data were statistically evaluated using analysis of variance and the Tukey posttest. The significance level was set at 5%.ResultsThe development of apical periodontitis was confirmed in all infected groups. Bone destruction was larger in the AP group compared with the AP-O group (P < .05). Blood analysis showed that the AP and AP-O groups showed higher numbers of lymphocytes, leukocytes, monocytes, eosinophils, and expressions of tumor necrosis factor alpha and IL-6 compared with the C and C-O groups (P < .05). In contrast, the presence of leukocytes, lymphocytes, and the expression of IL-6 decreased in the AP-O group compared with the AP group (P < .05).Conclusionsω-3 PUFA supplementation influences the systemic effects caused by apical periodontitis, decreasing the number of leukocytes, lymphocytes, and IL-6 in rat blood.     

Immunoexpression of Interleukin 17 in Apical Periodontitis Lesions

Introduction

Interleukin (IL)-17 expression has been detected in apical periodontitis lesions, but its role in the disease process remains unclear. The present study compared the expression of IL-17 in periradicular cysts and granulomas and evaluated the association of this cytokine with clinical and radiographic findings.

Methods

Apical periodontitis lesions (18 cysts and 20 granulomas) were obtained from 38 patients subjected to periradicular surgery. Some clinical, radiographic, and cone-beam computed tomographic features were recorded. Silanized slides containing paraffin sections were used for the immunohistochemical reactions using anti–IL-17 antibody. Image analysis was performed using an optical microscope, and each sample was divided into 5 high-power fields, which were evaluated for the expression of IL-17 in the epithelium and connective tissues. Results were evaluated for correlations with the lesion size and the occurrence of symptoms and sinus tract.

Results

Expression of IL-17 was significantly higher in cysts than in granulomas (P = .02). Among the periradicular cysts, a thin epithelium showed significantly increased labeling for IL-17 when compared with a hyperplastic epithelium (P = .003). IL-17 expression was usually associated with focal accumulations of polymorphonuclear leukocytes. No association of IL-17 expression with symptoms, sinus tract, or lesion size was observed (P > .05).

Conclusions

The present study reinforces the notion that IL-17 may take part in the pathogenesis of apical periodontitis lesions. A role in the exacerbation of chronic inflammation and cyst formation is suspected. Further studies are required to shed light on the specific functions of IL-17 in periradicular inflammatory processes.     

Prevalence of Ciliated Epithelium in Apical Periodontitis Lesions

Introduction

This article reports on the morphologic features and the frequency of ciliated epithelium in apical cysts and discusses its origin.

Methods

The study material consisted of 167 human apical periodontitis lesions obtained consecutively from patients presenting for treatment during a period of 12 years in a dental practice operated by one of the authors. All of the lesions were obtained still attached to the root apices of teeth with untreated (93 lesions) or treated canals (74 lesions). The former were obtained by extraction and the latter by extraction or apical surgery. Specimens were processed for histopathologic and histobacteriologic analyses. Lesions were classified, and the type of epithelium, if present, was recorded.

Results

Of the lesions analyzed, 49 (29%) were diagnosed as cysts. Of these, 26 (53%) were found in untreated teeth, and 23 (47%) related to root canal–treated teeth. Ciliated columnar epithelium was observed partially or completely lining the cyst wall in 4 cysts, and all of them occurred in untreated maxillary molars. Three of these lesions were categorized as pocket cysts, and the other was a true cyst.

Conclusions

Ciliated columnar epithelium-lined cysts corresponded to approximately 2% of the apical periodontitis lesions and 8% of the cysts of endodontic origin in the population studied. This epithelium is highly likely to have a sinus origin in the majority of cases. However, the possibility of prosoplasia or upgraded differentiation into ciliated epithelium from the typical cystic lining squamous epithelium may also be considered.     

Dens Invaginatus: Clinical Implications and Antimicrobial Endodontic Treatment Considerations

Dens invaginatus or dens in dente is a developmental dental anomaly resulting from an invagination of the enamel organ into the dental papilla during odontogenesis. Radiographically, it is usually seen as a radiolucent invagination surrounded by a radiopaque area (enamel) limited to the tooth crown or extending into the root. Because the invagination is opened to the oral cavity, it can retain saliva, food remnants, and bacteria. In conditions where the enamel lining of the invagination is naturally absent or lost because of caries, bacterial cells and products can diffuse from the invagination through the dentin tubules to reach the pulp and cause disease. Management of teeth with dens invaginatus includes preventive sealing or filling of the invagination, or if the pulp is affected, therapeutic options include vital pulp therapy, nonsurgical root canal treatment, apexification or regenerative endodontic procedures, periradicular surgery, intentional replantation, or extraction. It is recommended that the invagination be always approached, regardless of the type of dens invaginatus. The root canal should be treated whenever the pulp is irreversibly inflamed or necrotic. Endodontic management of teeth with dens invaginatus is often tricky because of its anatomic complexity, and special and customized strategies should be devised. This review discusses the endodontic implications of this anomaly and the current treatment recommendations based on anatomic, pathological, and technologic considerations.     

A Survey of Patients' Preferences for the Treatment of Teeth with Apical Periodontitis

Introduction

This research aimed to investigate the preference of patients in Toronto, Canada for management of a tooth affected by painful apical periodontitis when considering its retention via root canal treatment (RCT) and its extraction followed by no replacement, replacement with an implant-supported crown, fixed, or removable partial prostheses.

Methods

Data were collected through a mail-out survey of the University of Toronto Faculty of Dentistry patients, which was complemented by a convenience sample of patients in 10 community practices in Toronto (n = 1000, response rate = 43%). Participants were asked to select their general preference for anterior and posterior teeth with apical periodontitis between saving the tooth or extraction and their specific preference for tooth retention via RCT or extraction. By using bivariate and logistic regression analyses, we applied the Gelberg-Andersen Behavioral Model for Vulnerable Populations to the preference questions to understand the influential factors (P ≤ .05).

Results

Participants' specific preference for tooth retention via RCT was slightly but significantly lower than their general preference (anterior tooth, 93.7% versus 97.2%; posterior tooth, 83.8% versus 89.6%; P < .005). Higher annual income, previous RCT, functional dentition, good/excellent self-rated oral health, and regular dental visits were associated with higher preferences for tooth retention in response to different questions.

Conclusions

The high preference for retaining a tooth in general was moderated by the specific consideration of RCT to retain the tooth. When RCT and extraction are viable options, patients should be advised about the treatment options in an impartial manner and encouraged to communicate their preferences.     

Stem Cell Marker Expression in Persistent Apical Periodontitis

Introduction

This study evaluated the expression of CD90 (mesenchymal stem cell) and Sox2 (progenitor stem cell) markers in persistent apical periodontitis (PAP) (n = 16) and primary periapical lesions (PPLs) (n = 10).

Healing of Apical Periodontitis after Nonsurgical Treatment in Patients with Type 2 Diabetes

Introduction

The purpose of this prospective study was to compare the success of primary root canal treatment between type 2 diabetic and nondiabetic patients and to investigate the effect of periapical healing on glycated hemoglobin (HbA1c) in type 2 diabetic patients with apical periodontitis.

Genetic Polymorphisms in RANK and RANKL are Associated with Persistent Apical Periodontitis

Introduction

The outcome of root canal treatment has been reported as intimately related to the host response. Genetic polymorphisms might be associated with apical periodontitis repair. The aim of this study was to evaluate the association between receptor activator of nuclear factor kappa B (RANK), receptor activator of nuclear factor kappa B ligand (RANKL), and osteoprotegerin (OPG) genetic polymorphisms with persistent apical periodontitis (PAP) in Brazilian subjects.

Elevated Cytokine Levels in Gingival Crevicular Fluid of Teeth with Apical Periodontitis

IntroductionBiomarkers assayed from gingival crevicular fluid (GCF) are a potential tool for endodontic diagnosis and for monitoring treatment response. This cross-sectional study measured cytokines in GCF from teeth with apical periodontitis and evaluated their relationship with preoperative pain and other clinical findings.MethodsParticipants presenting for root-end resection surgery due to apical periodontitis diagnosis (n = 56) underwent standardized clinical testing and completed preoperative questionnaires. GCF from diseased and control teeth were collected, processed, and analyzed. Mann-Whitney U and Wilcoxon tests were used to examine the cytokine levels in diseased compared to healthy control teeth. We also assessed the relationship of cytokine levels with clinical findings.ResultsInterleukins (IL)-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, interferon-γ, and tumor necrosis factor-⍺ (TNF-⍺) were detected in GCF. TNF-⍺ levels were significantly higher in GCF collected from diseased versus control teeth (P = .02) and increased IL-1β levels in diseased teeth were detected (P = .06). Lower IL-10 levels were observed in teeth with a sinus tract and/or swelling compared to teeth without a sinus tract and/or swelling (P = .08). Cytokine levels did not clearly relate to the presence of pain.ConclusionsElevated levels of proinflammatory cytokines, including TNF-⍺ and IL1- β, were detected in GCF from diseased teeth compared to the healthy controls. Additional studies are needed to further investigate the utility of these biomarkers for objectively evaluating periradicular pathology.