Prevalence of unculturable bacteria in the periapical abscess: A systematic review and meta-analysis.

OBJECTIVE: To assess the prevalence of unculturable bacteria in periapical abscess, radicular cyst, and periapical granuloma. METHODS: PubMed, Scopus, Science Direct, and Ovid databases were systematically searched from January 1990 to May 2020. All the included studies were cross-sectional design. The risk of bias was assessed using Joanna Briggs Institute check-list. Heterogeneity was described using meta-regression and mixed-effects model for lesion, country, and sequence technique moderators. Funnel plot and unweighted Egger's regression test were used to estimate the publication bias. Microbiome data on diversity, abundance, and frequency of unculturable bacteria in the periapical lesions were reviewed, analysed, and the principal component analysis (PCA) was performed. RESULTS: A total of 13 studies out of 14,780, were selected for the final analysis. These studies focused on the prevalence of unculturable bacteria in periapical abscesses and related lesions. Approximately 13% (95% CI: 7-23%) of the cumulative number of bacteria derived from periapical abscesses was unculturable. Country moderator significantly (P = 0.05) affects the diversity summary proportion. While the pooled frequency of unculturable bacteria was 8%; 95% CI: 5, 14%, the estimate of the pooled abundance of unculturable bacteria was 5%; 95% CI: 2, 12% with a significant (P = 0.05) country moderator that affects the abundance summary proportion. Of the 62 unculturable bacteria, 35 were subjected to PCA and Peptostreptococcus sp. oral clone CK035 was the most abundant species in periapical abscesses. Hybridization techniques were found to be the most reliable molecular methods in detecting the abundance and frequency of unculturable bacteria. CONCLUSION: The significant prevalence of unculturable bacteria in the periapical abscess, suggests that they are likely to play, a yet unknown, critical role in the pathogenesis and progression of the disease. Further research remains to be done to confirm their specific contributions in the virulence and disease progression.

MRSA Septicemia With Septic Arthritis and Prostatic, Intraretinal, Periapical, and Lung Abscesses.

INTRODUCTION: Methicillin-resistant staphylococcus aureus (MRSA) bacteremia is a life-threatening illness and a major global health care problem. It can cause metastatic and complicated infections. CASE PRESENTATION: A 58-year-old man with uncontrolled type 2 diabetes mellitus presented with altered mental status after a fall. He was found to have a hip fracture, diabetic ketoacidosis, and MRSA bacteremia. This was complicated by septic knee arthritis, prostatic abscess, intraretinal abscess, periapical abscesses, and pulmonary abscesses. He was treated with intravenous vancomycin and oral linezolid and eventually recovered. DISCUSSION: Severe metastatic MRSA infection was likely due, in part, to the patient's uncontrolled diabetes, as he has no underlying immunodeficiency and was HIV negative. Prostatic abscesses are a relatively rare occurrence that typically develop in immunocompromised patients. CONCLUSION: This case is an interesting confluence of sequelae of MRSA bacteremia and reinforces the necessity for clinicians to be diligent when evaluating a patient with a suspected prostatic abscess.

A clinical trial comparing antimicrobial efficacy of "essential oil of Ocimum sanctum" with triple antibiotic paste as an intracanal medicament in primary molars.

OBJECTIVES: To evaluate the aerobic and anaerobic antimicrobial efficacy of Ocimum Sanctum (Tulsi) essential oil and compare it with that of triple antibiotic paste (TAP) by collecting microbiological samples from the root canals of primary molars. STUDY DESIGN: Forty children were selected for the study and were randomly divided into two groups of twenty each, namely, TAP group and O. sanctum group (basil). Six intracanal samples were collected for every patient, comprising of two each after access opening, irrigation and after 3 days of intracanal medicament placement. These samples were cultured in aerobic and anaerobic environment and later colony-forming units (CFUs) were counted and intragroup as well as intergroup comparison was done. RESULTS: Analysis of the results showed that there was a statistically significant reduction in CFUs after using essential oil of O. sanctum as an intracanal medicament. Saline use also leads to a statistically significant reduction in CFUs irrespective of the intracanal medicament used. TAP showed better antibiotic properties in comparison with that of O. sanctum. CONCLUSION: Antibiotic use is often associated with the adverse effects and development of resistance due to injudicious use. O. sanctum can be used in cases of long-standing infection owing to its antimicrobial efficacy and anti-inflammatory potential as an intracanal medicament in primary teeth.

Capnocytophaga endodontalis sp. nov., Isolated from a Human Refractory Periapical Abscess.

A novel Gram-negative, capnophilic, fusiform bacterium, designated strain ChDC OS43T, was isolated from a human refractory periapical abscess in the left mandibular second molar and was characterized by polyphasic taxonomic analysis. The 16S rRNA gene sequence revealed that the strain belongs to the genus Capnocytophaga, as it showed sequence similarities to Capnocytophaga ochracea ATCC 27872T (96.30%) and C. sputigena ATCC 33612T (96.16%). The prevalent fatty acids of strain ChDC OS43T were isoC15:0 (57.54%), C16:0 (5.93%), C16:0 3OH (5.72%), and C18:1 cis 9 (4.41%). The complete genome of strain ChDC OS43T was 3,412,686 bp, and the G+C content was 38.2 mol%. The average nucleotide identity (ANI) value between strain ChDC OS43T and C. ochracea ATCC 27872T or C. sputigena ATCC 33612T was >92.01%. The genome-to-genome distance (GGD) value between strain ChDC OS43T and C. ochracea ATCC 27872T or C. sputigena ATCC 33612T was 32.0 and 45.7%, respectively. Based on the results of phenotypic, chemotaxonomic, and phylogenetic analysis, strain ChDC OS43T (= KCOM 1579T = KCTC 5562T = KCCM 42841T = JCM 32133T) should be classified as the type strain of a novel species of genus Capnocytophaga, for which the name Capnocytophaga endodontalis sp. nov. is proposed.

Evaluación de Lesiones Periapicales en Pacientes Derivados a Cirugía Periapical Mediante Tomografía Computarizada de Haz Cónico / Evaluation of Periapical Lesions by Cone Beam Computed Tomography in Patients Referred for Apical Surgery

El uso de la tomografía computarizada de haz cónico (CBCT) en endodoncia ha ido en aumento, justificando su uso en casos más complejos, como cirugías periapicales. El objetivo fue evaluar las características imagenológicas encontradas en un grupo de pacientes derivados a cirugía periapical, mediante el uso de CBCT. Se realizó un estudio observacional descriptivo, en un grupo de pacientes, derivados a cirugía periapical, a los cuales se realizó un examen de CBCT, evaluación clínica y radiografía periapical. Un total de 18 pacientes fueron examinados (6 hombres y 12 mujeres), cuyas edades estaban entre los 19 y 64 años de edad. El diámetro mayor de las lesiones varió entre 6 mm a 16 mm. El uso de CBCT en cirugías periapicales entrega información más completa al cirujano, ya que permite mayor precisión al realizar el acceso quirúrgico y detecta un mayor número de lesiones periapicales que con la radiografía periapical, logrando en casos complejos un mejor diagnóstico y planificación del tratamiento.

The use of cone beam computed tomography (CBCT) in endodontics has increased, justifying its use in more complex cases, such as apical surgery. The aim was to evaluate the radiologic characteristics found in a group of patients referred to apical surgery, using CBCT. A descriptive study was conducted in a group of patients referred for apical surgery. In these patients, a clinical examination, a conventional radiographic evaluation and CBCT were performed. A total of 18 patients were examined (6 men and 12 women), ages were between 19 and 64 years old. The major diameter of the lesions ranged from 6 mm to 16 mm. The use of CBCT in apical surgery provides more complete information to the surgeon, allowing greater precision when performing surgical access and detects a greater number of periapical lesions than with conventional radiography. In complex cases is possible obtain better diagnosis and treatment planning.

Molecular Identification of Cultivable Bacteria From Infected Root Canals Associated With Acute Apical Abscess

Abstract The objective of this study was to investigate the bacterial composition present in root canals of teeth associated with acute apical abscess by molecular identification (16S rRNA) of cultivable bacteria. Two hundred and twenty strains isolated by culture from 20 root canals were subjected to DNA extraction and amplification of the 16S rRNA gene (PCR), followed by sequencing. The resulting nucleotide sequences were compared to the GenBank database from the National Center of Biotechnology Information through BLAST. Strains not identified by sequencing were submitted to clonal analysis. The association of microbiological findings with clinical features and the association between microbial species were also investigated. Fifty-nine different cultivable bacteria were identified by 16S rRNA gene sequencing, belonging to 6 phyla, with an average number of 6 species per root canal. Molecular approaches allowed identification of 99% of isolates. The most frequently identified bacteria were Prevotella spp., Pseudoramibacter alactolyticus, Parvimonas micra, Dialister invisus, Filifactor alocis, and Peptostreptococcus stomatis. Positive association was found between Prevotella buccae and Pseudoramibacter alactolyticus and between Parvimonas micra and Prevotella nigrescens (both p<0.05). It was concluded that the microbiota of infected root canals associated with acute apical abscess is diverse and heterogeneous, composed mainly of anaerobic Gram-negative bacteria, with the great majority belonging to the phyla Firmicutes and Bacteroidetes.

Resumo O objetivo deste estudo foi investigar a composição bacteriana de canais radiculares associados com abscesso apical agudo através de identificação molecular (16S rRNA) de bactérias cultiváveis. Duzentas e vinte cepas, de 20 casos, isoladas por cultura foram submetidas a extração de DNA e amplificação do gene 16S rRNA (PCR), seguido de sequenciamento. As sequências de nucleotídeos obtidas foram comparadas com o banco de dados (GenBank) do National Center of Biotechnology Information através do BLAST. Cepas não identificadas pelo sequenciamento foram submetidas à clonagem. Associação de achados microbiológicos e características clínicas e associação entre espécies bacterianas também foram investigadas. Cinquenta e nove bactérias cultiváveis diferentes foram identificadas pelo sequenciamento do gene 16S rRNA, pertencentes a 6 filos, numa média de 6 espécies por canal. Método molecular permitiu identificação de 99% das cepas isoladas. As bactérias mais frequentes foram Prevotella spp., Pseudoramibacter alactolyticus, Parvimonas micra, Dialister invisus, Filifactor alocis, Peptostreptococcus stomatis. Associação positiva foi encontrada entre Prevotella buccae e Pseudoramibacter alactolyticus, e entre Parvimonas micra e Prevotella nigrescens (p<0,05). Foi concluído que a microbiota de canais radiculares infectados associados com abscesso apical agudo é diversa e heterogênea, composta principalmente por anaeróbios Gram-negativos, pertencentes aos filos Firmicutes e Bacteroidetes.

Complex Apical Intraradicular Infection and Extraradicular Mineralized Biofilms as the Cause of Wet Canals and Treatment Failure: Report of 2 Cases.

This article describes 2 cases that showed persistent intracanal exudation (wet canal) even after several visits of antimicrobial endodontic treatment. Histologic and histobacteriologic investigation was conducted for determination of the cause. The 2 cases involved teeth with apical periodontitis lesions, which presented persistent exudation refractory to treatment after several visits. In case 1, it was not possible to achieve a dry canal, and surgery had to be performed. In case 2, attempts to dry the canal succeeded and the canal was filled, but follow-up examination showed an enlarged apical periodontitis lesion and extraction was performed. Biopsy specimens consisting of the root apex and apical periodontitis lesion for case 1 and the whole root for case 2 were subjected to histologic and histobacteriologic analyses. Both cases showed complex bacterial infection in the apical root, affecting both the intraradicular space and the outer root surface. Case 1 showed bacterial biofilms in ramifications, on untouched walls, and extending to the external root surface to form a thick and partially mineralized structure with high bacterial density. Different bacterial morphotypes were evidenced. Case 2 had a ledge on the apical canal wall created during instrumentation, which was filled with necrotic debris, filling material, and bacteria. The walls of the apical portion of the canal were covered by a bacterial biofilm, which was continuous with a thick extraradicular biofilm covering the cementum and dentin in resorptive defects. The extraradicular biofilm showed areas of mineralization and was dominated by filamentous bacteria. The 2 cases with wet canals and treatment failure were associated with complex persistent infection in the apical part of the root canal system extending to form thick and partially mineralized biofilm structures (calculus) on the outer apical root surface.

Bacterial diversity of symptomatic primary endodontic infection by clonal analysis

Abstract The aim of this study was to explore the bacterial diversity of 10 root canals with acute apical abscess using clonal analysis. Samples were collected from 10 patients and submitted to bacterial DNA isolation, 16S rRNA gene amplification, cloning, and sequencing. A bacterial genomic library was constructed and bacterial diversity was estimated. The mean number of taxa per canal was 15, ranging from 11 to 21. A total of 689 clones were analyzed and 76 phylotypes identified, of which 47 (61.84%) were different species and 29 (38.15%) were taxa reported as yet-uncultivable or as yet-uncharacterized species. Prevotella spp., Fusobacterium nucleatum, Filifactor alocis, and Peptostreptococcus stomatis were the most frequently detected species, followed by Dialister invisus, Phocaeicola abscessus, the uncharacterized Lachnospiraceae oral clone, Porphyromonas spp., and Parvimonas micra. Eight phyla were detected and the most frequently identified taxa belonged to the phylum Firmicutes (43.5%), followed by Bacteroidetes (22.5%) and Proteobacteria (13.2%). No species was detected in all studied samples and some species were identified in only one case. It was concluded that acute primary endodontic infection is characterized by wide bacterial diversity and a high intersubject variability was observed. Anaerobic Gram-negative bacteria belonging to the phylum Firmicutes, followed by Bacteroidetes, were the most frequently detected microorganisms.

[Cervico-facial cellulitis during pregnancy: about a series of 10 cases in Mali]. / Cellulite cervico-faciale au cours de la grossesse. À propos d'une série de 10 cas au Mali.

The objective of this work was to analyze the predisposing factors, diagnostic and therapeutic aspects of cervico-facial cellulitis on pregnancies and to determine maternal-fetal prognosis. We conducted a longitudinal observational descriptive study from January 2011 to March 2013 including records from pregnant women with cervicofacial cellulitis treated at the Oto-Rhino-Laryngology (ORL) and cervico-facial surgery department at Gabriel Touré Hospital in Bamako. Ten women met our inclusion criteria. The median age was 23 years. The entry way was dental in all cases. Three women had taken antibiotics and 3 others antibiotics associated with non steroidal anti-inflammatory. The medico-surgical treatment had permitted to cure 8 cases. Two cases of death were recorded and 4 cases of stillbirths. The cervico-facial cellulitis during pregnancy is a serious pathology that can be life-threatening to the mother and or child. Prevention is based on the control of dental status and informing women about the importance of dental hygiene.

Macrophage cell activation with acute apical abscess contents determined by interleukin-1 Beta and tumor necrosis factor alpha production.

INTRODUCTION: This clinical study has investigated the antigenic activity of bacterial contents from exudates of acute apical abscesses (AAAs) and their paired root canal contents regarding the stimulation capacity by levels of interleukin (IL)-1 beta and tumor necrosis factor alpha (TNF-α) throughout the root canal treatment against macrophage cells. METHODS: Paired samples of infected root canals and exudates of AAAs were collected from 10 subjects. Endodontic contents were sampled before (root canal sample [RCS] 1) and after chemomechanical preparation (RCS2) and after 30 days of intracanal medication with calcium hydroxide + chlorhexidine gel (Ca[OH]2 + CHX gel) (RCS3). Polymerase chain reaction (16S rDNA) was used for detection of the target bacteria, whereas limulus amebocyte lysate was used to measure endotoxin levels. Raw 264.7 macrophages were stimulated with AAA exudates from endodontic contents sampled in different moments of root canal treatment. Enzyme-linked immunosorbent assays were used to measure the levels of TNF-α and IL-1 beta. RESULTS: Parvimonas micra, Porphyromonas endodontalis, Dialister pneumosintes, and Prevotella nigrescens were the most frequently detected species. Higher levels of endotoxins were found in samples from periapical exudates at RCS1 (P < .005). In fact, samples collected from periapical exudates showed a higher stimulation capacity at RCS1 (P < .05). A positive correlation was found between endotoxins from exudates with IL-1 beta (r = 0.97) and TNF-α (r = 0.88) production (P < .01). The significant reduction of endotoxins and bacterial species achieved by chemomechanical procedures (RCS2) resulted in a lower capacity of root canal contents to stimulate the cells compared with that at RCS1 (P < .05). The use of Ca(OH)2 + CHX gel as an intracanal medication (RCS3) improved the removal of endotoxins and bacteria from infected root canals (P < .05) whose contents induced a lower stimulation capacity against macrophages cells at RCS1, RCS2, and RCS3 (P < .05). CONCLUSIONS: AAA exudates showed higher levels of endotoxins and showed a greater capacity of macrophage stimulation than the paired root canal samples. Moreover, the use of intracanal medication improved the removal of bacteria and endotoxins from infected root canals, which may have resulted in the reduction of the inflammatory potential of the root canal content.

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.

Craniocervical necrotizing fasciitis of odontogenic origin with thoracic extension.

Craniocervical necrotizing fasciitis is an uncommon but aggressive infection with high morbidity and mortality. We present a case of craniocervical necrotizing fasciitis with thoracic extension caused by a dental infection in a 56-year-old man, with a successful outcome involving broad-spectrum intravenous antibiotics and an aggressive surgical debridement.

Viral-bacterial associations in acute apical abscesses.

OBJECTIVE: Viral-bacterial and bacterial synergism have been suggested to contribute to the pathogenesis of several human diseases. This study sought to investigate the possible associations between 9 candidate endodontic bacterial pathogens and 9 human viruses in samples from acute apical abscesses. STUDY DESIGN: DNA extracts from purulent exudate aspirates of 33 cases of acute apical abscess were surveyed for the presence of 9 selected bacterial species using a 16S ribosomal RNA gene-based nested polymerase chain reaction (PCR) approach. Single or nested PCR assays were used for detection of the human papillomavirus (HPV) and herpesviruses types 1 to 8. RESULTS: Two-thirds of the abscess samples were positive for at least one of the target viruses. Specifically, the most frequently detected viruses were HHV-8 (54.5%); HPV (9%); and varicella zoster virus (VZV), Epstein-Barr virus (EBV), and HHV-6 (6%). Bacterial DNA was present in all cases and the most prevalent bacterial species were Treponema denticola (70%), Tannerella forsythia (67%), Porphyromonas endodontalis (67%), Dialister invisus (61%), and Dialister pneumosintes (57.5%). HHV-8 was positively associated with 7 of the target bacterial species and HPV with 4, but all these associations were weak. Several bacterial pairs showed a moderate positive association. Viral coinfection was found in 6 abscess cases, but no significant viral association could be determined. CONCLUSIONS: Findings demonstrated that bacterial and viral DNA occurred concomitantly in two-thirds of the samples from endodontic abscesses. Although this may suggest a role for viruses in the etiology of apical abscesses, the possibility also exists that the presence of viruses in abscess samples is merely a consequence of the bacterially induced disease process. Further studies are necessary to clarify the role of these viral-bacterial interactions, if any, in the pathogenesis of acute apical abscesses.

[Cerebral actinomycosis pseudotumor: a case report]. / Actinomycose cérébrale d'aspect pseudotumoral: à propos d'un cas.

INTRODUCTION: Cerebral actinomycosis is rare and difficult to diagnose. CASE REPORT: We report a case of a 45-year-old man hospitalized for seizures associated with fever and left hemiparesis. The white cell count and C-reactive protein were elevated. HIV serology was negative. Blood cultures remained sterile. The CT scan revealed hyperdense nodular lesions in the occipital area, with annular contrast uptake and peripheral edema causing a mass effect, suggestive of brain metastasis. The pathology examination of a surgical specimen disclosed cerebral actinomycosis. A dental origin of the infection was suspected. Hemiparesis remained after a 12-month antibiotic regimen associated with dental care and short-term corticosteroid therapy. CONCLUSION: Actinomycosis should be discussed as a possible diagnosis for all cerebral lesions, particularly in patients with a potential dental infection. Histology is required for positive diagnosis. Antibiotic therapy alone is generally sufficient; surgery is often performed for diagnostic purposes.

Apical actinomycosis: case report.

Actinomycosis has increasingly been recognized as a cause of persistent or recurrent periapical disease associated with endodontic therapy. After conventional root canal therapy of the lower left first and second molars, a 24-year-old woman presented with a persistent periapical lesion associated with one of the sinus tracts. The lesion was surgically removed, and actinomycosis was diagnosed on the basis of biopsy results. The clinical and histologic features of this rare condition are discussed.

Real-time polymerase chain reaction of "red complex" (Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola) in periradicular abscesses.

OBJECTIVE: The red complex bacteria (Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola) have been implicated, either singly or in combination, in the development of various forms of periodontal diseases. The aim of this study was to investigate the presence of "red complex" in acute periradicular abscesses by real-time polymerase chain reaction (PCR) method. STUDY DESIGN: Microbial samples were collected by aspiration from 32 cases diagnosed as acute periradicular abscess. DNA was extracted from the samples by using a QIAamp DNA mini-kit and analyzed with real-time PCR. RESULTS: At least 1 member of the red complex was found in 84% of the cases. In general T. denticola, P. gingivalis, and T. forsythia were detected in 65.6%, 43.7%, and 40.6% of the cases, respectively. Red complex was detected in 15.6% of samples taken from acute periradicular abscesses. CONCLUSIONS: Our findings suggest that "red complex" can participate in the pathogenesis of acute periradicular abscesses.

Spread of odontogenic infections in Port Harcourt, Nigeria.

PURPOSE: Odontogenic infections constitute a substantial portion of diseases encountered by oral and maxillofacial surgeons. Infections start from dental tissues and sometimes rapidly spread to contiguous spaces. The consequence is a fulminant disease with significant morbidity and mortality. The study was aimed at studying the pattern of spread, approach to management, and outcome of these infections at a Nigerian teaching hospital. PATIENTS AND METHODS: A retrospective study of all patients with orofacial infections who presented to our center over an 18-month period was carried out. The medical records were reviewed to retrieve the following: age, gender, source of infection, anatomic fascial spaces involved, associated medical conditions, various treatment modalities, types of antibiotics administered, causative micro-organisms, length of stay in the hospital, and any complications encountered. Infections were classified into 2 categories: those that are confined to the dentoalveolar tissues belong to category I, and those that have spread into the local/regional soft tissue spaces and beyond belong to category II. RESULTS: Odontogenic infections constituted 11.3% of the total oral and maxillofacial surgery cases. A total of 261 patients were treated for odontogenic infections. There were 146 female patients (59.8%) and 98 male patients (40.2%) in the first category, whereas the second category comprised 10 male patients (58.8%) and 7 female patients (41.2%). The fascial spaces involved, in descending order, were submasseteric in 10 (22.7%), submandibular in 9 (20.5%), and sublingual in 6 (13.6%). The causative micro-organisms commonly found were Klebsiella and Streptococcus spp. Incision and drainage were performed in the 17 cases with spreading infection. Amoxicillin, amoxicillin/clavulanate, and metronidazole were the most routinely administered antibiotics. CONCLUSIONS: Our experience shows that delay in presentation, self-medication, aging, male gender, and unusual causative agents are some of the factors associated with spread. Therefore efforts must be made to further improve public dental awareness.

Biofilms and apical periodontitis: study of prevalence and association with clinical and histopathologic findings.

INTRODUCTION: This study evaluated the prevalence of bacterial biofilms in untreated and treated root canals of teeth evincing apical periodontitis. The associations of biofilms with clinical conditions, radiographic size, and the histopathologic type of apical periodontitis were also investigated. METHODS: The material comprised biopsy specimens from 106 (64 untreated and 42 treated) roots of teeth with apical periodontitis. Specimens were obtained by apical surgery or extraction and were processed for histopathologic and histobacteriologic techniques. RESULTS: Bacteria were found in all but one specimen. Overall, intraradicular biofilm arrangements were observed in the apical segment of 77% of the root canals (untreated canals: 80%; treated canals: 74%). Biofilms were also seen covering the walls of ramifications and isthmuses. Bacterial biofilms were visualized in 62% and 82% of the root canals of teeth with small and large radiographic lesions, respectively. All canals with very large lesions harbored intraradicular biofilms. Biofilms were significantly associated with epithelialized lesions (cysts and epithelialized granulomas or abscesses) (p < 0.001). The overall prevalence of biofilms in cysts, abscesses, and granulomas was 95%, 83%, and 69.5%, respectively. No correlation was found between biofilms and clinical symptoms or sinus tract presence (p > 0.05). Extraradicular biofilms were observed in only 6% of the cases. CONCLUSIONS: The overall findings are consistent with acceptable criteria to include apical periodontitis in the set of biofilm-induced diseases. Biofilm morphologic structure varied from case to case and no unique pattern for endodontic infections was identified. Biofilms are more likely to be present in association with longstanding pathologic processes, including large lesions and cysts.

Distribution of Porphyromonas gingivalis fimA genotypes in primary endodontic infections.

OBJECTIVE: Long fimbriae (FimA) are important virulence factors of Porphyromonas gingivalis. Based on the diversity of the fimA gene, this species is classified into 6 genotypes. This study surveyed samples from primary endodontic infections for the presence of these P. gingivalis fimA variants. STUDY DESIGN: Genomic DNA isolated from samples taken from 25 root canals of teeth with chronic apical periodontitis and 25 aspirates from acute apical abscess was used as template in polymerase chain reaction (PCR) assays directed toward the detection of the different P. gingivalis fimA genotypes. RESULTS: Porphyromonas gingivalis was detected by a 16S rRNA gene-based PCR in 36% of the total number of cases sampled (44% of chronic apical periodontitis and 28% of abscess aspirates). In cases of chronic apical periodontitis, P. gingivalis variant type IV was the most prevalent (24%), followed by types I (20%), II (16%), and III (8%). In acute abscess samples, variant type II was the most prevalent (12%), followed by types III and IV (8% of each) and type I (4%). Combinations of up to 3 different genotypes were detected in a few cases. No single fimA genotype variant or combination thereof was significantly associated with symptoms. Overall, fimA types IV (16%), II (14%), and I (12%) were the most prevalent. CONCLUSIONS: Findings demonstrated that different P. gingivalis fimA genotypes can be present in primary endodontic infections.